Professor Yang Gao

Associate Dean (International), Professor of Space Autonomous Systems
BEng (1st Hons), PhD, FIET, FRAeS, SMIEEE, FHEA
+44 (0)1483 683446
11 BA 01
PA: Janet Sheldrick
+44 (0)1483 683639


Areas of specialism

Robotic sensing and perception; Visual GNC; Under-actuated slew control; Robot soil interaction; Biomimetic mechanisms

University roles and responsibilities

  • Associate Dean (International) for Faculty of Engineering & Physical Sciences (FEPS)
  • Professor of Space Autonomous Systems at Surrey Space Centre (SSC)
  • Director of FAIR-SPACE Hub and Head of SSC-STAR Lab
  • Chair of FEPS International Relations Committee
  • Member of University Global Strategy Committee
  • Member of FEPS Executive Committee
  • Member of FEPS Research Committee

Affiliations and memberships

Institute of Engineering and Technology (IET) and Royal Aeronautical Society (RAeS)
Elected Fellow
IEEE Technical Committees within Computational Intelligence Society (CIS) and Robotics and Autonmation Society (RAS)
Royal Society Newton International Fellowship Committee


In the media


Research interests

Research collaborations

Indicators of esteem

  • Research Grants (>£15M):
    • Research Councils and Agencies: EPSRC (2017-2020, 2016-2017, 2012-2016, 2012-2013); STFC (2014-2016, 2006-2007); InnovateUK (2015-2018); NDA (2016-2020); RAEng (2015-2016; 2011-2012; 2008-2009); EU FP7 (2011-2014; 2008-2012);
    • Space Agencies: UKSA (2017-2020, 2016-2017, 2015-2016); ESA (2017-2018, 2008-2011);
    • Industrial Companies: Airbus D&S (2017-2020, 2013-2019; 2009-2012); CAS-CIOMP (2018-2020); Sellafield (2014-2018); OHB/Kayser-Threde (2014-2017); SSTL (2007-2008); FCO (2007-2008).
    • Fellowships & Scholarships: SCEPTrE Fellowship (2010-2011); SMF Fellowship (2002-2004); NTU Scholarship for PhD Research (2000-2002); Singapore Ministry of Education Scholarship for Undergraduate Study (1996-2000).
  • Awards & Prizes:
    • Supervised PhD research: International Astronautical Federation’s 3AF Edmond Brun Silver Medal (2013); COSPAR's Outstanding Paper Award (2016); First Prize of UKSEDS Lunar Rover Competition (2017)
    • Times Higher Education - One of ten young leading academics in the UK who are making a very significant contribution to their disciplines (2008)
    • First Prize of IEEE Asia-Pacific Postgraduate Paper Contest (2002)
    • Motorola Book Prize on Robotics and Automation (2000);
    • NTU Dean's List Awards (2000, 1999, 1998, 1997).

My teaching


Postgraduate research supervision

Completed postgraduate research projects I have supervised

My publications


Davies P, Phipps A, Taylor M, Curiel ADS, Baker A, Gao Y, Sweeting M, Parker D, Crawford IA, Ball AJ, Wilson L (2007) Uk lunar science missions: Moonlite & moonraker, 2007 3RD INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN SPACE TECHNOLOGIES, VOLS 1 AND 2 pp. 774-779 IEEE
Lewinger WA, Comin F, Ransom S, Richter L, Al-Milli S, Spiteri C, Gao Y, Saaj CM (2013) Multi-Level Soil Sensing Systems to Identify Safe Trafficability Areas for Extra-Planetary Rovers, ESA
Yuen P, Gao Y, Griffiths A, Coates A, Muller JP, Smith A, Walton D, Leff C, Hancock B, Shin D (2013) ExoMars rover pancam: Autonomous & computational intelligence [application notes], IEEE Computational Intelligence Magazine 8 (4) pp. 52-61
As a part of the Aurora programme for Mars exploration, funded by the United Kingdom Space Agency (UKSA) and European Space Agency (ESA), the UK contributes to the Exobiology on Mars (ExoMars) rover science and engineering programme, with a scheduled launch in 2018; Hence, our Panoramic Camera (PanCam) [9][15] research and development (R&D) is timely. PanCam consists of two stereo Wide Angle Cameras (WAC) and one High Resolution Camera (HRC). While the development is still ongoing, we used funding awarded by the University College London (UCL) Graduate School to conduct investigations in the Himalayas and at Mount Everest Base Camp (EBC), according to the ExoMars rover Reference Surface Mission (RSM). The investigations included capturing stereo and high resolution images using stereo WAC emulators and HRC emulator at altitudes 3490 m, 5150 m and above. Images from different WAC filters, and color images from HRC were acquired at various Pan and Tilt Unit (PTU) mast positions. Our investigation results show significant reduction in data volume with minimum loss in image quality. Furthermore, we introduce a novel autonomous and computational intelligent system called Mission-Specific Data Processor (MSDP) for the rover. It includes Pan-Cam, Visual Data Fusion (VDF), Learning-enabled Object Detection (LOD), Self-Learning Agent (SLA) [22], and Environment Model Library (EML) as part of the rover's computational intelligence [7]. © 2013 IEEE.
Gao Y, Er MJ (2004) Adaptive Modeling and Control of Drug Delivery Systems Using Generalized Fuzzy Neural Networks, In: Ruan D, Zeng X (eds.), Intelligent sensory evaluation Springer Verlag
This book collects a number of representative methods on sensory evaluation.
Gao Y, Er MJ, Leithead WE, Leith DJ (2001) On-line adaptive control of robot manipulators using dynamic fuzzy neural networks, PROCEEDINGS OF THE 2001 AMERICAN CONTROL CONFERENCE, VOLS 1-6 pp. 4828-4833 IEEE
Spiteri C, Al-Milli S, Gao Y, de Leon AS (2015) Real-time visual sinkage detection for planetary rovers, ROBOTICS AND AUTONOMOUS SYSTEMS 72 pp. 307-317 ELSEVIER SCIENCE BV
Gouache T, Gao Y, Coste P, Gourinat Y (2009) Experimental study of dual-reciprocating-drilling mechanism using design of experiment approach, European Space Agency, (Special Publication) ESA SP 670 SP
Y. Gao et al. proved the feasibility of designing a woodwasp
(Sirex Noctilio) inspired drill for Earth and extraterrestrial
drilling and boring activities [1]. But before
an optimised dual reciprocating drill design can be proposed,
it is necessary to better understand the driving
factors and the important parameters that influence this
mechanism?s performance and, power and force requirements.
Indeed the insect?s ovipositor is "optimised",
through natural selection, for wood; but the dual reciprocating
drill will bore into much different substrates. Here,
the numerous parameters that could influence the studied
mechanism?s performance are identified and the test
bench to
Wu YH, Gao Y, Lin JW, Raus R, Zhang SJ, Watt M (2014) Low-cost, high-performance monocular vision system for air bearing table attitude determination, Journal of Spacecraft and Rockets 51 (1) pp. 66-75
Attitude determination is one of the most important prerequisites for the implementation of an air bearing table. In this context, computer vision is shown to be an enabling technology; a cost-effective monocular camera vision system, including hardware setup and navigation software, has been developed to determine the attitude of the air bearing table. Both infrared light-emitting diodes and filter are selected to simplify image processing, thereby maximizing the attitude update rate.Afiducial marker system uses five infrared light-emitting diodes with four in the same plane and the fifth outside the plane. This noncoplanar design not only improves the attitude determination accuracy, but also provides an element of robustness via a fiducial marker fault diagnosis and process method in case one of the lightemitting diodes is obscured by the top balance mass or is faulty. The static experimental results show that the system can provide attitude accuracy of 0.06 deg and angular velocity accuracy of 0.15 deg /s with an attitude update rate of at least 10 Hz. Finally, a yaw-axis maneuver is performed to demonstrate the system performance under dynamic conditions. The developed system could be reused to support testing for other scientific space missions, which represents a major added value of this work. Copyright © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Er MJ, Wu S, Gao Y (2003) Dynamic Fuzzy Neural Networks: Architectures, Algorithms and Applications, McGraw-Hill
Yu C-Q, Ju H-H, Gao Y, Cui P-Y (2009) A bilateral teleoperation system for planetary rovers, Proceedings of International Conference on Computational Intelligence and Software Engineering
In this paper, a bilateral teleoperation system (BTS) is proposed for planetary rover remote control and operation. This is a continuation of the work presented in on computer-simulated virtual environment, that can be used as a predictive display module in the BTS. In the proposed system, a haptic device is used by the human operators to control planetary rovers as driving a car. Dynamic model of the rover is used and a passive-based bilateral teleoperation scheme is adopted to achieve the stability of the close-loop control. Kinematic model of the rover is used to get the torque distribution algorithm and applied to calculate the corresponding torque for each wheel based on the desired linear speed and heading angle of the rover. Buffer unit is designed to address the issue of variable time-delay caused by the Internet. Lab-based experiments have been carried out using the BH2 rover. The test results demonstrate good performance of the proposed system.
Gowen R, Smith A, Winter B, Theobald C, Rees K, Ball AJ, Hagermann A, Sheridan S, Brown P, Oddy T, Dougherty M, Church P, Gao Y, Jones A, Joy KH, Crawford I, Pike T, Kumar S, Hopf T, Wells N, Green K, Ryden K (2008) An update on MoonLITE, Proceedings of 59th International Astronautical Congress 7 pp. 4359-4369 International Astronautical Federation
MoonLITE is a proposed, UK led lunar science mission involving 4 scientific penetrators that will make in situ measurements at widely separated locations on the Moon. MoonLITE will create the first global lunar network with nodes near and far-side, and in permanently shaded crater(s). With such a network MoonLITE will be able to determine much about the interior of the Moon, including characterisation of its core. Penetrator(s) at the poles will seek and characterise frozen volatiles, possibly of cometary origin and of great importance both to human exploration and to astrobiology. MoonLITE penetrators will reach the Moon at ~300 m/s and so must be able to stand the forces associated with this impact. As part of a programme aimed to establish reliable penetrator technologies the first full-scale impact trials have been conducted and are described here.
Er MJ, Gao Y, Sun Y (2001) Real-Time Hybrid Adaptive Fuzzy Control of a SCARA, European Control Association
Gouache T, Gao Y, Gourinat Y, Coste P (2010) Wood Wasp Inspired Space and Earth Drill, In: Biomimetics, Learning from Nature INTECH
Gao Y, Er MJ (2002) Nonlinear identification and control using a generalized fuzzy neural network, PROCEEDINGS OF THE 41ST IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-4 pp. 1363-1368 IEEE
Er MJ, Gao Y, Lim MH, Ng SY (2001) Dynamic Fuzzy Neural Networks Control of a SCARA, European Control Association
Gao Y, Er MJ (2003) Modelling, control, and stability analysis of non-linear systems using generalized fuzzy neural networks, INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE 34 (6) pp. 427-438 TAYLOR & FRANCIS LTD
Gouache T, Gao Y, Coste P, Gourinat Y (2009) Experimental Parametric Evaluation of Dual-reciprocating Drilling Mechanism Performance, ESA SP European Space Agency
Si J, Gao Y, Chanik A (2015) Slew Control of Prolate Spinners Using Single-Magnetorquer, Journal of Guidance, Control, and Dynamics 39 (3) pp. 719-727 American Institute of Aeronautics and Astronautics
Gao Y, Policella N, Kirchner F (2013) Computational intelligence for space systems and operations, IEEE Computational Intelligence Magazine 8 (4) pp. 10-63
Yang S, Er MJ, Gao Y (2001) A high performance neural-networks-based speech recognition system, IJCNN'01: INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-4, PROCEEDINGS pp. 1527-1531 IEEE
Burroughes G, Gao Y (2016) Ontology-Based Self-Reconfiguring Guidance, Navigation, and Control for Planetary Rovers, Journal of Aerospace Information Systems 13 (8) pp. 316-328 American Institute of Aeronautics and Astronautics
Certain limitations exist in autonomous software and guidance, navigation, and control architectures developed for extraterrestrial planetary exploration rovers in regard to fault tolerance, changes in environment, and changes in rover capabilities. To address these limitations, this paper outlines a self-reconfiguring guidance, navigation, and control architecture, using an ontology-based rational agent to enable autonomous reconfiguration of mission goals, software architecture, software components, and the control of hardware components during the run time. This new architecture was evaluated through implementation onboard a rover and tested in challenging, Mars-like environments, both simulated and real world, and was found to be highly reliable, fault tolerant, and adaptable.
Shaukat A, Burroughes G, Gao Y (2015) Self-Reconfigurable Robotics Architecture Utilising Fuzzy and Deliberative Reasoning, 2015 SAI INTELLIGENT SYSTEMS CONFERENCE (INTELLISYS) pp. 258-266 IEEE
Gowen RA, Smith A, Fortes AD, Barber S, Brown P, Church P, Collinson G, Coates AJ, Collins G, Crawford IA, Dehant V, Chela-Flores J, Griffiths AD, Grindrod PM, Gurvits LI, Hagermann A, Hussmann H, Jaumann R, Jones AP, Joy KH, Karatekin O, Miljkovic K, Palomba E, Pike WT, Prieto-Ballesteros O, Raulin F, Sephton MA, Sheridan S, Sims M, Storrie-Lombardi MC, Ambrosi R, Fielding J, Fraser G, Gao Y, Jones GH, Kargl G, Karl WJ, MacAgnano A, Mukherjee A, Muller JP, Phipps A, Pullan D, Richter L, Sohl F, Snape J, Sykes J, Wells N (2011) Penetrators for in situ subsurface investigations of Europa, Advances in Space Research 48 (4) pp. 725-742
Gao Y (2016) Contemporary Planetary Robotics: An Approach Toward Autonomous Systems, Wiley-VCH
The book provides a comprehensive introduction to the key techniques and technologies that help to achieve autonomous space systems for cost-effective, high performing planetary robotic missions. Main topics covered include robotic vision, surface navigation, manipulation, mission operations and autonomy, being explained in
both theoretical principles and practical use cases. The book recognizes the importance of system design hence discusses practices and tools that help take mission concepts to baseline design solutions, making it a practical piece of scientific reference suited to a variety of practitioners in planetary robotics.
Samperio R, Shala K, Cheng Y, Gao Y (2011) Design and Implementation of Autonomous Software for Planetary Rovers using ROS,
Delfa Victoria JM, Von Stryk O, Policella N, Donati A, Gallant M, Gao Y (2012) Metrics for planetary rover planning & scheduling algorithms, Performance Metrics for Intelligent Systems (PerMIS) Workshop pp. 47-52
In addition to its utility in terrestrial-based applications, Automated Planning and Scheduling (P&S) has had a growing impact on space exploration. Such applications require an influx of new technologies to improve performance while not comprimising safety. As a result, a reliable method to rapidly assess the effectiveness of new P&S algorithms would be desirable to ensure the fulfillment of of all software requirements. This paper introduces RoBen, a missionindependent benchmarking tool that provides a standard framework for the evaluation and comparison of P&S algorithms. RoBen considers metrics derived from the model (the system on which the P&S algorithm will operate) as well as user input (e.g., desired problem complexity) to automatically generate relevant problems for quality assessment. A thorough description of the algorithms and metrics used in RoBen is provided, along with the preliminary test results of a P&S algorithm solving RoBen-generated problems. Copyright © 2012.
Gao Y, Er MJ, Mastorakis N, Leithead WE, Leith DJ (2000) Trajectory tracking of robot manipulators using adaptive fuzzy neural control, System and Control: Theory and Applications pp. 71-78
This paper presents a new control scheme utilizing fuzzy neural networks for trajectory control of robot manipulators. The adaptive capability of the fuzzy neural controller ensures that high performance can be achieved and maintained under time-varying conditions. This intelligent control scheme consists of two portions. In the first portion, the fuzzy neural networks with dynamic structure, in short DFNNs, are constructed to estimate dynamics of the robot model. The second portion is the fuzzy neural controller, which is built based on model learning and on-line weight adjustment. Computer simulations of a two-link robot manipulator demonstrate the effectiveness and efficiency of the proposed scheme.
Gao Y, Ellery A, Jaddou M, Vincent J, Eckersley S (2005) A novel penetration system for in situ astrobiological studies, International Journal of Advanced Robotic Systems 2 (4) pp. 281-286
Due to ultraviolet flux in the surface layers of most solar bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration and drilling to detect chemical signature for extant or extinct life. To address this issue, we present a micro-penetrator concept (mass
Shaukat A, Gao Y, Kuo JA, Bowen BA, Mort PE (2016) Visual classification of waste material for nuclear decommissioning, Robotics and Autonomous Systems 75 (Part B) pp. 365-378 Elsevier
Redundant and nonoperational buildings at nuclear sites go through the process of ?decommissioning?, involving decontamination of nuclear waste material and demolition of physical infrastructure. One challenging problem currently faced by the nuclear industry during this process is the segregation of redundant waste material into a choice of ?post-processes? based upon the nature and extent of its radioactivity that may pose a serious threat to the environment. Following an initial inspection, waste materials are subjected to treatment, disruption and consigned to various types of export containers. To date, the process of objects (waste) classification is performed manually. In order to automate this process, robotic platforms can be deployed that utilise robust and fast vision systems for visual classification of nuclear waste material. This paper proposes a novel solution incorporating a machine vision system for autonomous identification of waste material from decommissioned nuclear plants. Rotation and scale invariant moments are used to describe object shapes in the visual scene whereas a random forest learning algorithm performs object classification. Using nuclear waste simulants (from the nuclear plant decommissioning process), an exhaustive ?proof-of-concept? quantitative assessment of the proposed technique is performed, in order to test its applicability within the current problem domain.
Gouache TP, Gao Y, Coste P, Gourinat Y (2011) First experimental investigation of dual-reciprocating drilling in planetary regoliths: Proposition of penetration mechanics, PLANETARY AND SPACE SCIENCE 59 (13) pp. 1529-1541
Rau R, Gao Y, Watt M (2010) Review and Analysis of Single-Thruster Attitude Control Algorithms for Spinning Spacecraft, Proc. 60th IAC (IAC-10.C1.3.7) International Astronautical Federation
Gao Y, Frame TED, Pitcher C (2015) Peircing the extraterrestrial surface: Integrated robotic drill for planetary exploration, IEEE Robotics and Automation Magazine 22 (1) pp. 45-53
© 2015 IEEE.As we explore our solar system and other extraterrestrial bodies, the subsurface plays a vital role in allowing us to peer back into the history of a particular body, looking for life or signs that it may have been habitable. This can be achieved by using a form of drill or penetrator, although traditional technologies require large masses to produce an overhead force (OHF) that pushes the drill into the subsurface. Dual reciprocating drilling (DRD) is a new biologically inspired technology based on the wood wasp ovipositor. It consists of two reciprocating backward-facing teethed halves that generate a drilling force that reduces the required overhead penetration force and mass requirements. The Surrey Space Centre (SSC) has overseen the design, development, and testing of a proof-of-concept model with funding from European Space Agency. The system is now evolving to include a drive mechanism within the drill head and bays for scientific instrumentation.
Gao Y, Ellery A, Sweeting MN (2007) Bioinspired drill for planetary sampling: Literature survey, conceptual design, and feasibility study, JOURNAL OF SPACECRAFT AND ROCKETS 44 (3) pp. 703-709 AMER INST AERONAUTICS ASTRONAUTICS
Delfa J, Fratini S, Policella N, Stryk O, Gao Y, Donati A (2014) Planning Mars Rovers with Hierarchical Timeline Networks, Acta Futura (9) pp. 21-29
Gao Y (2008) Optical flow based techniques for ExoMars rover autonomous navigation, Proceeding iSAIRAS European Space Agency
Gao Y, Er MJ (2005) An intelligent adaptive control scheme for postsurgical blood pressure regulation., IEEE Trans Neural Netw 16 (2) pp. 475-483
This paper presents an adaptive modeling and control scheme for drug delivery systems based on a generalized fuzzy neural network (G-FNN). The proposed G-FNN is a novel intelligent modeling tool, which can model unknown nonlinearities of complex drug delivery systems and adapt to changes and uncertainties in these systems online. It offers salient features, such as dynamic fuzzy neural topology, fast online learning ability and adaptability. System approximation formulated by the G-FNN is employed in the adaptive controller design for drug infusion in intensive care environment. In particular, this paper investigates automated regulation of mean arterial pressure (MAP) through intravenous infusion of sodium nitroprusside (SNP), which is one attractive application in automation of drug delivery. Simulation studies demonstrate the capability of the proposed approach in estimating the drug's effect and regulating blood pressure at a prescribed level.
Smith A, Crawford IA, Gowen RA, Ball AJ, Barber SJ, Church P, Coates AJ, Gao Y, Griffiths AD, Hagermann A, Joy KH, Phipps A, Pike WT, Scott R, Sheridan S, Sweeting M, Talboys D, Tong V, Wells N, Biele J, Chela-Flores J, Dabrowski B, Flannagan J, Grande M, Grygorczuk J, Kargl G, Khavroshkin OB, Klingelhoefer G, Knapmeyer M, Marczewski W, McKenna-Lawlor S, Richter L, Rothery DA, Seweryn K, Ulamec S, Wawrzaszek R, Wieczorek M, Wright IP, Sims M (2009) LunarEX-a proposal to cosmic vision, EXPERIMENTAL ASTRONOMY 23 (3) pp. 711-740 SPRINGER
Gao Y, Er MJ (2002) Adaptive intelligent control of MIMO nonlinear systems based on generalized fuzzy neural network, PROCEEDING OF THE 2002 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-3 pp. 2333-2338 IEEE
Er MJ, Gao Y (2003) Adaptive control strategy for blood pressure regulation using a fuzzy neural network, 2003 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN AND CYBERNETICS, VOLS 1-5, CONFERENCE PROCEEDINGS pp. 2120-2125 IEEE
Shaukat A, Bajpai A, Gao Y (2015) Reconfigurable SLAM Utilising Fuzzy Reasoning, European Space Agency, ESTEC
Delfa JM, Policella N, Gao Y, Stryk O (2012) Design Concepts for a new Temporal Planning Paradigm,
Gouache T, Gao Y, Coste P, Gourinat Y (2009) Experimental Study of Dual Reciprocating Drilling Mechanism using Design of Experiment Approach, European Space Agency
Kömle NI, Kaufmann E, Kargl G, Gao Y, Rui X (2008) Development of thermal sensors and drilling systems for lunar and planetary regoliths, Advances in Space Research 42 (2) pp. 363-368
Gao Y, Er MJ (2005) NARMAX time series model prediction: feedforward and recurrent fuzzy neural network approaches, FUZZY SET SYST 150 (2) pp. 331-350 ELSEVIER SCIENCE BV
The nonlinear autoregressive moving average with exogenous inputs (NARMAX) model provides a powerful representation for time series analysis, modeling and prediction due to its capability of accommodating the dynamic, complex and nonlinear nature of real-world time series prediction problems. This paper focuses on the modeling and prediction of NARMAX-model-based time series using the fuzzy neural network (FNN) methodology. Both feedforward and recurrent FNNs approaches are proposed. Furthermore, an efficient algorithm for model structure determination and parameter identification with the aim of producing improved predictive performance for NARMAX time-series models is developed. Experiments and comparative studies demonstrate that the proposed FNN approaches can effectively learn complex temporal sequences in an adaptive way and they outperform some well-known existing methods.
Wu Y-H, Gao Y, Raus R, Watt M (2012) Tradeoff Analysis of Attitude-Control Slew Algorithms for Prolate Spinner, JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 35 (4) pp. 1143-1157 AMER INST AERONAUT ASTRONAUT
Delfa JM, Gao Y, Policella N, Donati A (2011) A Domain-Independent Pattern Recognition System to Support Space Mission Planning , Proceeding of, European Space Agency
Gao Y, Ellery A, Jaddou M, Vincent J, Eckersley S (2007) Planetary micro-penetrator concept study with biomimetric drill and sampler design, IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 43 (3) pp. 875-885 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Gowen RA, Smith A, Coates AJ, Crawford IA, Scott RF, Church PD, Gao Y, Pike WT, Flanagan J (2009) Development of kinetic penetrators for exploration of airless solar system bodies, In: Kargl G, Komle N, Ball AJ, Lorenz RD (eds.), Penetrometry in the solar system II
Gao Y, Er MJ, Du J (2004) Narmax-model-based time series prediction: feedforward and recurrent fuzzy neural network approaches, APPLIED COMPUTATIONAL INTELLIGENCE pp. 537-542 WORLD SCIENTIFIC PUBL CO PTE LTD
Yeomans B, Shaukat A, Gao Y (2015) Testing Saliency Based Techniques For Planetary Surface Scene Analysis, European Space Agency
Gao Y, Phipps A, Taylor M, Crawford IA, Ball AJ, Wilson L, Smith A, Parker D, Sweeting M, Da Silva Curiel A, Davies P (2007) Concepts and instruments of UK moonlite & moonraker missions, International Astronautical Federation - 58th International Astronautical Congress 2007 2 pp. 1037-1045
Returning to the Moon has been advocated by a number of planetary scientists in order to answer several key scientific questions. The UK has an active lunar science community keen to support (robotic) lunar exploration. However, for several years, these interests have been eclipsed by the drive to Mars. Recently there is a renewed global interest in the Moon, demonstrated by the Vision for Space Exploration in the USA, the evolving Global Exploration Partnership, and new lunar missions from Europe, Japan, China and India. The ESA Aurora programme may also broaden its focus to embrace the Moon as well as Mars - realising that many of the major technical challenges that are faced by Mars missions could be de-risked by relatively inexpensive and timely lunar precursors. Surrey Satellite Technology Ltd. (SSTL) and Surrey Space Centre (SSC) have been preparing a 'smallsat' approach to achieving a low-cost lunar mission for more than a decade - including various activities, such as Phase B study of LunarSat funded by ESA and a current hardware contribution to the Chandrayaan-1 mission. With the recent successes in GIOVE-A, TOPSAT & BEIJING-1, alongside participation in Aurora & Chandrayaan-1, Surrey has developed capabilities for providing affordable engineering solutions to space exploration. In 2006, SSTL/SSC was funded by the UK Particle Physics and Astronomy Research Council (PPARC) (now included within the UK Science & Technology Facilities Council) to undertake a study on low-cost lunar mission concepts that could address key scientific questions. This paper presents some major results from this study (Phipps and Gao, 2006) and provides preliminary definitions of two down-selected mission proposals. Copyright IAF/IAA. All rights reserved.
Gao Y, Phipps A, Taylor M, Crawford IA, Ball AJ, Wilson L, Parker D, Sweeting M, Curiel ADS, Davies P, Baker A, Pike WT, Smith A, Gowen R (2008) Lunar science with affordable small spacecraft technologies: MoonLITE and Moonraker, PLANETARY AND SPACE SCIENCE 56 (3-4) pp. 368-377 PERGAMON-ELSEVIER SCIENCE LTD
Delfa JM, Policella N, Gallant M, Donati A, Bertrand R, von Stryk O, Gao Y (2012) RoBen: Introducing a benchmarking Tool for planetary rover planning & scheduling algorithms, SpaceOps 2012 Conference
Automated Planning & Scheduling Systems are nowadays applied in a wide range of spacecraft, from satellites to Mars rovers. The planner is responsible for the generation of valid plans that determine the activities to be performed by the spacecraft, given a set of goals and constraints (the problem), and taking into consideration the status of the spacecraft and environment. Therefore, it represents a critical system that needs to be strictly validated and verified. This paper presents a benchmarking tool called RoBen intended to characterize the performance of timeline planning systems. Using a number of metrics and heuristics, RoBen can generate synthetic problems of a given complexity in order to stress planners at different levels. At the same time, we are looking for properties that could help us to determine when a problem is unsolvable. © 2012 by Juan Delfa Victoria, TU Darmstadt, University of Surrey, European Space Agency.
Gao Y, Er MJ (2003) Adaptive fuzzy neural modeling and control scheme for mean arterial pressure regulation, IROS 2003: PROCEEDINGS OF THE 2003 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-4 pp. 1198-1203 IEEE
Raus R, Gao Y, Wu Y, Watt M (2012) Analysis of state-of-the-art single-thruster attitude control techniques for spinning penetrator, Acta Astronautica 76 pp. 60-78
The attitude dynamics and manoeuvre survey in this paper is performed for a mission scenario involving a penetrator-type spacecraft: an axisymmetric prolate spacecraft spinning around its minor axis of inertia performing a 90 spin axis reorientation manoeuvre. In contrast to most existing spacecraft only one attitude control thruster is available, providing a control torque perpendicular to the spin axis. Having only one attitude thruster on a spinning spacecraft could be preferred for spacecraft simplicity (lower mass, lower power consumption etc), or it could be imposed in the context of redundancy/ contingency operations. This constraint does yield restrictions on the thruster timings, depending on the ratio of minor to major moments of inertia among other parameters. The Japanese Lunar-A penetrator spacecraft proposal is a good example of such a single-thruster spin-stabilised prolate spacecraft. The attitude dynamics of a spinning rigid body are first investigated analytically, then expanded for the specific case of a prolate and axisymmetric rigid body and finally a cursory exploration of non-rigid body dynamics is made. Next two well-known techniques for manoeuvring a spin-stabilised spacecraft, the Half-cone/Multiple Half- cone and the Rhumb line slew, are compared with two new techniques, the Sector-Arc Slew developed by Astrium Satellites and the Dual-cone developed at Surrey Space Centre. Each technique is introduced and characterised by means of simulation results and illustrations based on the penetrator mission scenario and a brief robustness analysis is performed against errors in moments of inertia and spin rate. Also, the relative benefits of each slew algorithm are discussed in terms of slew accuracy, energy (propellant) efficiency and time efficiency. For example, a sequence of half-cone manoeuvres (a Multi-half-cone manoeuvre) tends to be more energy-efficient than one half-cone for the same final slew angle, but more time-consuming. As another example, the new Sector-Arc Slew and Dual-cone techniques are designed to overcome a specific restriction on attainable slew angle that is associated with the half-cone manoeuvre, giving one additional degree of freedom for designers to fine-tune. © 2012 Elsevier Ltd.
Bajpai A, Burroughes G, Shaukat A, Gao Y (2015) Planetary Monocular Simultaneous Localization and Mapping, JOURNAL OF FIELD ROBOTICS 33 (2) pp. 229-242 WILEY-BLACKWELL
Wu YH, Gao Y (2013) Precise spin Sync slew control based on nonlinear optimization for Spinning Spacecraft, Proceedings of the International Astronautical Congress, IAC 7 pp. 5024-5035
The paper aims to address the challenge of performing precise spin-axis reorientation maneuver for prolate spacecraft (e.g. kinetic planetary penetrators) spinning about its minimal inertia axis using a single body fixed attitude control thruster, which takes into account constraints of dynamics, phase boundary and slew time, etc. Spin stabilization is an attractive way for providing attitude pointing stability to a spacecraft due to its simplicity and ability to reject against various disturbances, such as gravity gradient disturbance torque and liquid sloshing disturbance torque. This is deemed applicable to various missions involving upper stages, multiple unit cubesats, and kinetic impactors such as for MoonLITE and NEOShield projects. Furthermore, for spinners using one attitude control thruster that is perpendicular to the spin axis is theoretically feasible and advantageous in terms of simplicity and redundancy in comparison to 3-axis stabilization control. Spin Sync slew algorithm is recently developed for the single thruster attitude control of prolate spinners. It possesses similar characteristic as Rhumb Line slew, but can be implemented to overcome the inherent singularity of the Rhumb Line slew and sun sensor failure. Both Spin Sync and Rhumb Line slews still have issues with residual nutation angle and potential divergence of the angular momentum trajectory. In this paper, a geometric method is proposed to estimate and compensate the angular momentum vector divergence. In addition, the paper presents solutions to achieve precise attitude control using spin sync slew. This is a difficult problem due to nonlinear and nonconvex attitude dynamics and constraints and is hence treated as a nonlinear multi-phase optimal control problem with constraints related to initial and terminal state, control torque magnitude, attitude dynamics, and slew time. Here, the optimization is achieved by direct transcription using Gauss pseudo-spectral method, in which the varying boundary problem is converted to a fixed boundary problem by varying optimization parameters. Computer simulations and results are provided to demonstrate the proposed approach. The optimal control achieved is also verified using engineering software simulator of 'Attitude Control Simulator for Spinning Spacecraft with Single Thruster'.
Gao Y, Ellery A (2006) Autonomous Navigation Based on Optic Flow for ExoMars Rovers, European Space Agency
Menon C, Lan N, Ellery A, Zangani D, Manning C, Vincent JFV, Bilhaut L, Gao Y, Carosio S, Jaddou M, Eckersley S (2006) Bio-inspired micro-drills for future planetary exploration, Proceedings of MNT for Aerospace Applications, CANEUS2006 2006
In a domain such as space technology, where robustness, mass, volume and power efficiency are key, biological organisms may provide inspiration for new systems with high performance. By using micro-technology processes, designers of space systems may take advantage of the millions of years over which miniaturised mechanisms in plants and animals have been optimised for survival. Space exploration often requires systems equipped with drills, and miniaturised drillers could enable a number of new space operations. Two natural digging systems have been studied as potential miniature space digging systems; the ovipositors of the female locust and of sirex noctilio, a species of woodwasp. Being insectoid systems, the mechanics of their design work on an inherently small scale, though they are also thought to be scalable. Results of preliminary studies, performed during collaboration between the Advanced Concepts Team of ESA, the University of Bath, the University of Surrey, D'appolonia and EADS-Astrium, are presented and discussed. Engineering solutions are proposed and analysed to assess the potential of new bio-inspired miniaturised digging systems for space applications. Copyright © 2006 by ASME.
Dennis LA, Fisher M, Aitken JM, Veres SM, Gao Y, Shaukat A, Burroughes G (2014) Reconfigurable Autonomy, KI - Künstliche Intelligenz 28 (3) pp. 199-207 Springer Berlin Heidelberg
This position paper describes ongoing work at the Universities of Liverpool, Sheffield and Surrey in the UK on developing hybrid agent architectures for controlling autonomous systems, and specifically for ensuring that agent-controlled dynamic reconfiguration is viable. The work outlined here forms part of the Reconfigurable Autonomy research project.
Sancho-Pradel DL, Gao Y (2010) A survey on terrain assessment techniques for autonomous operation of planetary robots, JBIS - Journal of the British Interplanetary Society 63 (5-6) pp. 206-217
A key challenge in autonomous planetary surface exploration is the extraction of meaningful information from sensor data, which would allow a good interpretation of the nearby terrain, and a reasonable assessment of more distant areas. In the last decade, the desire to increase the autonomy of unmanned ground vehicles (UGVs), particularly in terms of off-road navigation, has significantly increased the interest in the field of automated terrain classification. Although the field is relatively new, its advances and goals are scattered across different robotic platforms and applications. The objective of this paper is to present a survey of the field from a planetary exploration perspective, bringing together the underlying techniques, existing approaches and relevant applications under a common framework. The aim is to provide a comprehensive overview to the newcomer in the field, and a structured reference for the practitioners.
Li ZG, Er MJ, Gao Y (2003) An adaptive RBFN-based filter for adaptive noise cancellation, 42ND IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-6, PROCEEDINGS pp. 6175-6180 IEEE
Wu YH, Gao Y, Raus R, Watt M (2012) Single Thruster Attitude Control Software Simulator for Spinning Spacecraft,
Gao Y, Er MJ, Yang S (2001) Adaptive control of robot manipulators using fuzzy neural networks, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 48 (6) pp. 1274-1278 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Shaukat A, Spiteri C, Gao Y, Al-Milli S, Bajpai A (2013) Quasi-thematic feature detection and tracking for future rover long-distance autonomous navigation, ESA/ESTEC
This paper investigates state-of-the-art approaches for object detection and tracking employing models that can efficiently detect objects (specifically 'rock? on planet surfaces) in the visual scene in terms of semantic descriptions. Two models (i.e., ?visual saliency? and ?blob (shape-based) detection?) are presented here specifically focused towards future planetary exploration rovers. We believe that these two object detection techniques will abate some of the algorithmic limitations of existing methods with no training requirements, lower computational complexity and greater robustness towards visual tracking applications over long-distance planetary terrains. Comprehensive (quantitative) experimental analysis of the proposed techniques performed using three challenging benchmark datasets (i.e., from PANGU, RAL Space SEEKER and SSC lab-based test-bed) will be presented in this paper.
Gao Y, Ellery A, Jaddou M, Vincent J (2006) Bio-inspired drill for planetary subsurface sampling: Literature survey, conceptual design and feasibility study, Proceedings of AISB'06: Adaptation in Artificial and Biological Systems 2 pp. 71-77
It is widely acknowledged that the next significant challenge in planetary exploration is to be able to drill deeply (two meters seems the most scientifically valuable and the most technologically reasonable) into the surface of solar system bodies for chemical or physical data. Major limitation of using conventional rotary drills in low gravity environments (such as Mars, asteroids, comet, etc) is the need for high axial force, which suffers from big overhead mass, buckling problem, and power hungriness. Though drills using percussive motion may operate in low mass and power, the drilling rate is generally slow. Drawing inspiration from nature for a lightweight and energy efficient solution, we propose a novel drilling method based on the working mechanism of wood wasp ovipositors. The bio-inspired drill requires no reactive external force by applying two-valve-reciprocating motion. The proposed bio-inspired system indicates enhanced utility that is critical for space missions where premium is placed on mass, volume and power. Biological systems are similarly constrained making biomimetic technology uniquely suited and advantageous as a model of miniaturized systems. As a result of the European Space Agency (ESA) project on bionics and space system design [Ellery, 2005], this paper presents a conceptual design of the bio-inspired drill. Lab-based experiments have shown that the two-valve-reciprocating drilling method is feasible and has potential of improving drill efficiency without any additional overhead force or mass.
Bamber DC, Forshaw JL, Frame TE, Aglietti G, Geshnizjani R, Goerries S, Kornienko A, Levenhagen J, Gao Y, Chanik A (2015) Absolute Attitude Determination System for a Spherical Air Bearing Testbed,
Gao Y, Spiteri C, Pham MT, Al-Milli S (2014) A survey on recent object detection techniques useful for monocular vision-based planetary terrain classification, Robotics and Autonomous Systems 62 (2) pp. 151-167
Direct terrain classification from monocular images for autonomous navigation of planetary rovers is a relatively new and challenging research area, not only because of the hardware limitation of a rover, but also because the rocks and obstacles to be detected exhibit diverse morphologies and have no uniform properties to distinguish them from background soil. We present a survey of recently developed object detection techniques that can be useful for terrain classification for planetary rovers. We start with summarizing current vision-based terrain classification methods. We then provide a comprehensive and structured overview of recent object detection techniques, focusing on those applicable to terrain classification. © 2013 Elsevier B.V. All rights reserved.
Baker AM, Phipps A, Sweeting M, Ellery A, Yang G (2006) Challenges and options for an affordable small lunar sample-return mission, AIAA 57th International Astronautical Congress, IAC 2006 3 pp. 1862-1870
SSTL has been studying the application of its highly successful Low Earth Orbit micro and mini-satellites for lunar and planetary missions since 1996, through in-house funded design exercises and supported by ESA through Lunar and inner planet mission studies. Technical feasibility of a minisatellite lunar orbiter has been demonstrated. SSTL has since developed a range of improved subsystems and more advanced platforms, many of which have gained heritage in-orbit. These include the GMP-MiniSat platform with deployable solar arrays, accurate 3-axis stabilized attitude control, high resolution and wide field-of-view multispectral cameras and low cost bipropellant propulsion systems. Low cost launch options range from a Proton auxiliary payload launch direct to geostationary orbit, to prime passenger on a PSLV, to secondary payload alongside larger lunar missions. While SSTL is focused on low cost lunar orbiter development, it is jointly considering affordable means of conducting lunar landing, and ultimately sample return with the University of Surrey Space Centre. Lunar landing and sample return would demonstrate the applicability of low-cost small spacecraft technology to reduce the risk of high profile and barely affordable missions such as Mars Sample Return, by demonstrating key technologies, offering secondary science, and increased mission frequency to build enthusiastic public and political support. A parametric study for a lunar sample return mission from the south polar Aitken basin is highlighted, which has shown that a 15kg rover can in principle be landed on the lunar surface for a maximum surface stay of 150hours, subsequently returning a 200g sample to Earth, for a total launch mass from Earth orbit of less than 500kg, using a mixture of chemical and electric propulsion. This paper briefly considers the technology requirements and COTS technology availability for the separate mission stages, in order to establish how SSTL's low cost approach may be applicable to this challenging mission. This study is an ongoing area of research between SSTL and the University of Surrey Space centre.
Firstbrook DG, Harkness P, Gao Y (2014) High-powered ultrasonic penetrators in granular material, AIAA SPACE 2014 Conference and Exposition
This work investigates the effects of high-powered ultrasonics in granular material. The aim is to facilitate penetration in granular material in low-mass/ low-gravity environments. The results show that the weight on bit requirement for penetration is significantly reduced on application of direct ultrasonic vibration, especially in high relative density substrates.
Er MJ, Gao Y (2003) Robust adaptive control of robot manipulators using generalized fuzzy neural networks, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 50 (3) pp. 620-628 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Smith A, Crawford IA, Gowen RA, Ambrosi R, Anand M, Banerdt B, Bannister N, Bowles N, Braithwaite C, Brown P, Chela-Flores J, Cholinser T, Church P, Coates AJ, Colaprete T, Collins G, Collinson G, Cook T, Elphic R, Fraser G, Gao Y, Gibson E, Glotch T, Grande M, Griffiths A, Grygorczuk J, Gudipati M, Hagermann A, Heldmann J, Hood LL, Jones AP, Joy KH, Khavroshkin OB, Klingelhoefer G, Knapmeyer M, Kramer G, Lawrence D, Marczewski W, McKenna-Lawlor S, Miljkovic K, Narendranath S, Palomba E, Phipps A, Pike WT, Pullan D, Rask J, Richard DT, Seweryn K, Sheridan S, Sims M, Sweeting M, Swindle T, Talboys D, Taylor L, Teanby N, Tong V, Ulamec S, Wawrzaszek R, Wieczorek M, Wilson L, Wright I (2012) Lunar Net-a proposal in response to an ESA M3 call in 2010 for a medium sized mission, Experimental Astronomy 33 (2-3) pp. 587-644 Springer
Emplacement of four or more kinetic penetrators geographically
distributed over the lunar surface can enable a broad range of scientific exploration
objectives of high priority and provide significant synergy with planned
orbital missions. Whilst past landed missions achieved a great deal, they have
not included a far-side lander, or investigation of the lunar interior apart from a
very small area on the near side. Though the LCROSS mission detected water
from a permanently shadowed polar crater, there remains in-situ confirmation,
knowledge of concentration levels, and detailed identification of potential
organic chemistry of astrobiology interest. The planned investigations will
also address issues relating to the origin and evolution of the Earth?Moon
system and other Solar System planetary bodies. Manned missions would
be enhanced with use of water as a potential in-situ resource; knowledge of
potential risks from damaging surface Moonquakes, and exploitation of lunar
regolith for radiation shielding. LunarNet is an evolution of the 2007 LunarEX
proposal to ESA (European Space Agency) which draws on recent significant
advances in mission definition and feasibility. In particular, the successful
Pendine full-scale impact trials have proved impact survivability for many of
the key technology items, and a penetrator system study has greatly improved
Shala K, Gao Y (2010) Review and analysis of localization and mapping techniques for planetary rovers, Proceedings of iSAIRAS European Space Agency
Komle NI, Hutter ES, Kargl G, Ju H, Gao Y, Grygorczuk J (2008) Development Of Thermal, Sensors And Drilling Systems, For Application On Lunar Lander Missions, Earth, Moon and Planets 103 pp. 119-141 Springer Verlag
The upcoming lunar lander missions, for example Chang?e 2 from CNSA and
several mission proposals and studies currently under consideration at NASA (e.g. Neal
et al., ROSES 2006 Proposal to NASA, 2006), ESA (e.g. Hufenbach, European Workshop
on Lunar Landers, ESTEC, Noordwijk, The Netherlands, 2005; Foing, EPSC Abstracts, vol
2, EPSC2007-A-00422, European Planetary Science Congress, Potsdam, Germany, 2007)
and JAXA, Japan (Matsumoto et al., Acta Astronautica, 59:68?76, 2006) offer new possibilities
to measure the thermal properties of the lunar regolith and to determine the global
lunar heat flow more accurately than it is hitherto known. Both properties are of high
importance for the understanding of the lunar structure and the evolution of the Moon?Earth
system. In this paper we present some work on new thermal sensors to be used for in situ
investigations of the lunar soil in combination with novel drilling techniques applicable for
the lunar regolith. Such systems may preferably be mounted on mobile stations like the lunar
rover currently built for the Chinese Chang?e 2 mission. A general description of a presently
tested prototype of the lunar rover is given and mounting possibilities for a drilling system
and thermal sensors are shown. Then we discuss some options for thermal sensors and drills
and how they could be combined into one compact instrument. Subsequently a tube-like
sensor suitable for measuring the thermal conductivity of the material surrounding a borehole is described in more detail. Finally the performance of such a tube-shaped sensor when
applied in a lunar borehole is investigated by thermal modelling and compared with the
behaviour of a more conventional needle-shaped sensor.
Pitcher C, Gao Y (2015) Analysis of drill head designs for dual-reciprocating drilling technique in planetary regoliths, Advances in Space Research 56 (8) pp. 1765-1776 Elsevier
© 2015 COSPAR. The dual-reciprocating drill (DRD) is a biologically-inspired concept which has shown promise in planetary environments, requiring a lower overhead force than traditional rotary drilling techniques. By using two reciprocating backwards-facing teethed halves to grip the surrounding substrate, it generates a traction force that reduces the required overhead penetration force. Research into DRD has focused on the effects of operational and substrate parameters on performance compared to static penetration, with minimal study of the geometrical parameters which define the drill head. This paper presents the exploration of the effects of drill head design on drilling depth and power consumption. Sixteen variations of the original design were tested in planetary regolith simulants up to depths of 800. mm. The experiments showed relationships between final depth, total drill radius and cone shape, though the teeth design had a negligible effect on performance. These results can be used alongside the previous research to optimise the future design and operation of the DRD. Drill stem bending was seen to cause an increase in drilling speed and depth, leading to the exploration of the mechanics of diagonal drilling. This resulted in the proposal of a fully-integrated system prototype that incorporates both reciprocating and lateral motion mechanisms.
Gao Y, Liu J (2014) China's robotics successes abound, Science 345 (6196)
Wu SQ, Er MJ, Gao Y (2001) A fast approach for automatic generation of fuzzy rules by generalized dynamic fuzzy neural networks, IEEE TRANSACTIONS ON FUZZY SYSTEMS 9 (4) pp. 578-594 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Gao Y, Sweeting M, Eckersley S, Vincent JFV (2009) A ?micro? concept for a planetary penetrator & drill package, In: Kargl G, Komle NI, Ball AJ, Lorenz RD (eds.), Penetrometry in the solar system II Austrian Academy of Sciences Press
Wu Y, Gao Y, Raus R, Watt M (2012) Single Thruster Attitude Control Software Simulator for Spinning Spacecraft, 2012 IEEE AEROSPACE CONFERENCE IEEE
This paper presents a software simulator 'Attitude Control Simulator for Spinning Spacecraft with Single Thruster' in terms of design, software architecture, trade-off philosophy, etc. Design of the simulator was motivated by interest in kinetic penetrators for planetary exploration, and single thruster attitude control technology for spinning spacecraft. The use of a single thruster delivering a torque perpendicular to the spin-axis represents a huge improvement in mechanical simplicity and operational redundancy. Such a system can implement various slew algorithms, such as the traditional Half Cone, Multi-Half Cone, Rhumb Line and Spin Sync, as well as the newly developed Extended Half Cone, Dual Cone, Sector Arc and Multi-Sector Arc slew algorithms. The simulator consists of a GUI, Fault Management, Slew Algorithm Simulink Model and an Analytical Toolbox. The GUI interacts between the simulator and the users. Fault Management implements both parameter and hardware monitoring. Parameter monitoring will check the conflict of selected parameters with corresponding algorithm and desired performance, whilst hardware monitoring will check sensors status. With these functions, the users can specify various properties of the penetrator and carry out a fast trial. The Analytical Toolbox addendum will provide a thorough analysis and quantitative comparison of these algorithms in terms of tradeoffs between performance and cost. The trade-off works independently of the Simulink Model, but its results can be verified through simulation. The developed simulator will provide a useful tool for the simulation and evaluation of different state-of-the-art slew algorithms, system design tradeoff, and parameter analysis and design for system engineers. © 2012 IEEE.
Pham M-T, Gao Y, Hoang V-DD, Cham T-J (2010) Fast polygonal integration and its application in extending haar-like features to improve object detection, Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition pp. 942-949
Gao Y, Ellery A, Jaddou M, Vincent J (2006) Deployable wood wasp drill for planetary subsurface sampling, 2006 IEEE Aerospace Conference, Vols 1-9 pp. 405-411 IEEE
Shaukat A, Al-Milli S, Bajpai A, Spiteri C, Burroughes G, Gao Y, Lachat D, Winter M (2015) Next-Generation Rover GNC Architectures, European Space Agency, ESTEC
Gouache TP, Brunskill C, Scott GP, Gao Y, Coste P, Gourinat Y (2010) Regolith simulant preparation methods for hardware testing, PLANETARY AND SPACE SCIENCE 58 (14-15) pp. 1977-1984 PERGAMON-ELSEVIER SCIENCE LTD
Makhlouta M, Gao Y, Shala K (2008) A Vision and Behaviour Based Approach for Short-Range Autonomous Navigation of Planetary Rovers, ESA SP European Space Agency
Luo Y, Liu J, Gao Y, Lu Z (2014) Smartphone-controlled robot snake for urban search and rescue, Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 8917 pp. 352-363
© Springer International Publishing Switzerland 2014.Search and rescue robots would benefit from versatile locomotion ability and hence cope with varying environments. Robot snakes, with hyperredundant body and unique gaits, offer a promising solution to search and rescue applications. This paper presents a portable design of robot snakes that can be controlled from commercial mobile devices like the smartphones. The control results are validated and demonstrated using hardware prototypes.
Gao Y, Er MJ (2001) Adaptive fuzzy neural control of multiple-link robot manipulators, International Journal of Robotics and Automation 16 (4) pp. 172-182
This article presents the design, development, and implementation of a new adaptive fuzzy neural controller (AFNC) suitable for real-time industrial applications. The developed AFNC consists of a combination of a fuzzy neural network (FNN) controller and a supervisory PD controller. The salient features of the AFNC are: (1) dynamic fuzzy neural structure, that is, fuzzy control rules can be generated or deleted automatically; (2) fast on-line learning ability; (3) fast convergence of tracking error; (4) adaptive control; and (5) robust control, where global stability of the system is established using Lyapunov approach. Experimental evaluation conducted on a SEIKO TT-3000 SCARA robot demonstrates that excellent tracking performance can be achieved under time-varying conditions. The proposed controller also outperforms some of the existing adaptive fuzzy and neural controllers in terms of tracking speed and accuracy.
Yu C-Q, Ju H-H, Gao Y (2009) 3D virtual reality simulator for planetary rover operation and testing, Proceedings of International Conference on Virtual Environments, Human-Computer Interfaces, and Measurements Systems pp. 101-106
This paper describes a computer-simulated virtual reality environment for planetary rover operation and testing. The proposed 3D Virtual Rover Operation Simulator (VROS) consists of rover model, perception of the planetary surface, and rover-terrain contact model, which provides a simulation platform to test and validate different rover chassis design, navigation and locomotion algorithms, and to support rover operation. Lab-based experiments have been carried out and results can demonstrate various functions of VROS and its performance.
Gao Y, Er MJ (2004) Adaptive fuzzy neural control of mean arterial pressure through sodium nitroprusside infusion, 42ND IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-6, PROCEEDINGS pp. 2198-2203 IEEE
Pitcher C, Kömle N, Leibniz O, Morales-Calderon O, Gao Y, Richter L (2015) Investigation of the properties of icy lunar polar regolith simulants, Advances in Space Research 57 (5) pp. 1197-1208 Elsevier
As icy regolith is believed to exist in the subsurface of permanently shadowed areas near the lunar south pole, there is a growing interest in obtaining samples from these polar regions. To qualify for spaceflight, sampling instruments must demonstrate their ability to operate in the expected environment. However, there is currently no quantitative data detailing the extent and distribution of ice in polar regolith. While work has been done to determine the effects of water ice content in simulants such as JSC-1A, to date there has been no investigation into the properties of icy simulants of the regolith believed to be found at lunar polar regions. A series of experiments has therefore been conducted to determine the properties of icy NU-LHT-2M lunar highland simulant, an approximation of lunar polar regolith, at varying degrees of saturation. A number of procedures for preparing the simulant were tested, with the aim of defining a standardised technique for the creation of icy simulants with controlled water contents. Saturation of the highland simulant was found to occur at a water mass content between 13% and 17%, while cone penetration tests demonstrated that a significant increase in penetration resistance occurs at 5 ± 1%. Uniaxial compression tests showed an increase in regolith strength with water mass and density, which slows down as the saturation level is reached. The results presented here demonstrate the first characterisation of the properties of icy lunar polar regolith simulants, which can be expanded upon to further the understanding of its properties for use in future instrumentation testing.
Er MJ, Gao Y, Leithead WE, Leith DJ (2001) Lateral Auto-Pilot Design for an Agile Missile Using Dynamic Fuzzy Neural Networks, Proceeding of ECC European Control Association
Gao Y, Ellery A, Jaddou M, Vincent J, Eckersley S (2005) A Biologically-Inspired Penetration/Drilling/ Sampling System for in situ Astrobiological Studies, proceedings of TAROS Springer
Jiang H, Er MJ, Gao Y (2003) Feature extraction using wavelet packets strategy, 42ND IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-6, PROCEEDINGS pp. 4517-4520 IEEE
Wild A, Gao Y, Sweeting M (2008) Sensing and Autonomous High Precision Planetary Landers, ESA SP European Space Agency
Bajpai A, Gao Y (2013) End to end monocular slam system for planetary rovers, Proceedings of the International Astronautical Congress, IAC 13 pp. 10023-10028
Current techniques for the exploration of planetary surfaces are slow, and involve frequent human intervention. Rapid growth in complexity of future missions requires the development of ambitious technologies that may allow remotely deployable vehicles to carry out a majority of their tasks autonomously. Mapping and localisation is a key area of planetary exploration that can benefit from an increased level of autonomy, for instance in upcoming missions such as ExoMars and the ESA sample return proposal FASTER. Simultaneous Localisation And Mapping (SLAM) is a technique developed for terrestrial uses allow autonomous vehicles to calculate their position in an unknown environment, whilst also creating a map. This technique can be transferred to a planetary platform in order to allow the rover to better traverse through its environment without human intervention. While several techniques existed for implementing SLAM in a terrestrial environment, the use of SLAM for planetary exploration has not been explored in depth. The use of LIDAR, commonly used in terrestrial SLAM implementations, is a complex solution for use in space missions, and has yet to be robustly proven. Therefore, another means of observing the environment, a key part of the SLAM algorithm, is required. Monocular cameras together with vision processing algorithms present a simple scenario well suited to the scenario. The work presented in this paper comprises the design and implementation of a fully end-to-end, modular planetary SLAM system. The system takes data from the Planetary and Asteroid Natural scene Generation Utility, and using vision based algorithms passes observation data to one of three SLAM filters, the Extended Kalman Filter, the Extended Information Filter and FastSLAM. The results show that these techniques and filters are well suited to the planetary environment and provide a route towards extending rover autonomy. ©2013 by the International Astronautical Federation. All rights reserved.
Delfa JM, Policella N, Gallant M, Stryk O, Donati A, Gao Y (2012) Metrics for Planetary Rover Planning & Scheduling Algorithms, Proceedings of the Workshop on Performance Metrics for Intelligent Systems pp. 47-52 ACM
In addition to its utility in terrestrial-based applications, Automated Planning and Scheduling (P&S) has had a growing impact on space exploration. Such applications require an influx of new technologies to improve performance while not comprimising safety. As a result, a reliable method to rapidly assess the effectiveness of new P&S algorithms would be desirable to ensure the fulfillment of of all software requirements. This paper introduces RoBen, a mission-independent benchmarking tool that provides a standard framework for the evaluation and comparison of P&S algorithms. RoBen considers metrics derived from the model (the system on which the P&S algorithm will operate) as well as user input (e.g., desired problem complexity) to automatically generate relevant problems for quality assessment. A thorough description of the algorithms and metrics used in RoBen is provided, along with the preliminary test results of a P&S algorithm solving RoBen-generated problems.
Gao Y, Er MJ, Deng C (2002) Adaptive fuzzy neural control of nonlinear systems, COMPUTATIONAL INTELLIGENT SYSTEMS FOR APPLIED RESEARCH pp. 461-468 WORLD SCIENTIFIC PUBL CO PTE LTD
Sorensen TC, Bergman JES, Saunders C, Gao Y, Lappas V, Liddle D, Mouginis-Mark P, Nunes MA, Palmer P, Underwood C, Bridges C (2014) Using a constellation of small satellites to characterize the RF quiescence of the lunar farside, Proceedings of the International Astronautical Congress, IAC 6 pp. 4071-4083
Radio images of red-shifted 21-cm signals from neutral hydrogen originating from the very early Universe, the so-called Dark Ages before the first stars formed, are impossible to obtain from Earth due to man-made radio frequency interference (RFI) and the opacity of the ionosphere below
Pitcher C, Gao Y (2016) First Implementation of Burrowing Motions in Dual-Reciprocating Drilling Using an Integrated Actuation Mechanism, Advances in Space Research 59 (5) pp. 1368-1380 Elsevier
The dual-reciprocating drill (DRD) is a biologically-inspired low-mass alternative to traditional drilling techniques, using backwards-facing teethed halves to grip the surrounding substrate, generating a traction force that reduces the required overhead penetration force. Previous experiments using a proof-of-concept test bench have provided evidence as to the significant role of sideways movements and lateral forces in improving drilling performance. The system is also progressing to a first system prototype concept, in which an actuation mechanism is integrated within the drill heads. To experimentally determine the effect of lateral motions, a new internal actuation mechanism was developed to allow the inclusion of controlled sideways movements, resulting in the creation of the circular and diagonal burrowing motions. This paper presents an investigation into the performance of the reciprocation and burrowing motions by testing them in a planetary regolith simulant. Analysis of force sensor measurements has shown a relationship between the penetration and traction forces and the internal friction of the mechanism and depth achieved. These tests have also experimentally demonstrated the benefit of lateral motions in drilling performance, with both the burrowing mechanisms and drilling tests performed at an angle able to penetrate further than traditional vertical reciprocation, leading to the proposition of new burrowing and diagonal drilling mechanics. From this, a new fully integrated system prototype can be developed which incorporates lateral motions that can optimise the drilling performance.
Shaukat A, Blacker PC, Spiteri C, Gao Y (2016) Towards Camera-LIDAR Fusion-Based Terrain Modelling for Planetary Surfaces: Review and Analysis, Sensors 16 (11) MDPI
: In recent decades, terrain modelling and reconstruction techniques have increased research
interest in precise short and long distance autonomous navigation, localisation and mapping within
field robotics. One of the most challenging applications is in relation to autonomous planetary
exploration using mobile robots. Rovers deployed to explore extraterrestrial surfaces are required
to perceive and model the environment with little or no intervention from the ground station. Up
to date, stereopsis represents the state-of-the art method and can achieve short-distance planetary
surface modelling. However, future space missions will require scene reconstruction at greater
distance, fidelity and feature complexity, potentially using other sensors like Light Detection And
Ranging (LIDAR). LIDAR has been extensively exploited for target detection, identification, and depth
estimation in terrestrial robotics, but is still under development to become a viable technology
for space robotics. This paper will first review current methods for scene reconstruction and
terrain modelling using cameras in planetary robotics and LIDARs in terrestrial robotics; then
we will propose camera-LIDAR fusion as a feasible technique to overcome the limitations of
either of these individual sensors for planetary exploration. A comprehensive analysis will be
presented to demonstrate the advantages of camera-LIDAR fusion in terms of range, fidelity, accuracy
and computation.
Delfa JM, Gao Y, Policella N, Donati A (2011) A Domain-Independent Pattern Recognition System to Support Space Mission Planning, Proceedings of 11th Symposium on Advanced Space Technologies in
Automated planning has been applied to numerous fields such as computer games, industrial robotics and even highprofile missions like planning and scheduling activities for Martian rovers. A current trend among the researchers
is to apply automated planning in multiple space systems that work together in a coordinated fashion so as to attain highly complex mission goals. Even though automated planning and scheduling algorithms are mature in industrial
scenarios and robotics, little consideration has been given to multiple-agent space applications. In this paper, we describe the development of a domain configurable planner which can be used for different space mission comprising of multiple systems i.e. satellites or rovers.
The multiagent planning systems uses agent based modeling techniques, hierarchical task network (HTN) planning and a mixed approach from centralized and distributed planning. The initial results from the prototype planner are also discussed.
Spiteri C, Al-Milli S, Gao Y, Sarrionandia De León A (2015) Real-time visual sinkage detection for planetary rovers, Robotics and Autonomous Systems 72 pp. 307-317
© 2015 Elsevier B.V. All rights reserved.Identifying wheel sinkage for planetary exploration rovers can give a critical insight about the terrain traversability and in particular the characteristics of deformable soils that the rover travels on. This paper presents a monocular vision based approach that can detect and estimate the sinkage of a hybrid legged wheel in real time and robustly, with little sensitivity to changing operational conditions. The proposed method involves color-space segmentation that identifies the leg contour and consequently depth of wheel sinkage into the regolith. In addition, it enables dynamic analysis of the sinkage, hence making detection of non-geometric hazards possible while the rover moves. Extensive field trials have been conducted on natural deformable terrain. The experimental results demonstrate that the average discrepancy against annotated images is less than 1%.
Isarabhakdee P, Gao Y (2009) Cooperative Control of a Multi-tier Multi-agent Robotic System for Planetary Exploration, ESA SP European Space Agency
Gao Y, Er MJ (2001) Robust adaptive fuzzy neural control of robot manipulators, Proceedings of the International Joint Conference on Neural Networks 3 pp. 2188-2193
This paper presents a robust Adaptive Fuzzy Neural Controller (AFNC) suitable for trajectory control of robot manipulators. The proposed controller has the following salient features: (1) Self-organizing fuzzy neural structure, i.e. fuzzy control rules can be generated or deleted automatically according to their significence to the control system and the complexity of the mapped system, and no predefined fuzzy rules are required; (2) Online learning, i.e. no prescribed training models are needed for online learning; (3) Fast learning speed, i.e. Generalized Dynamic Fuzzy Neural Network (GD-FNN) algorithm provides an efficient learning method. Moreover, weights of the AFNC are modified without using the Back-Propagation (BP) iteration method. Structure and parameters identification of the AFNC are done automatically and simultaneously without partitioning the input space and selecting initial parameters a priori; (4) Fast convergence of tracking error, i.e. manipulator joints can track the desired trajectory very quickly; (5) Adaptive control, i.e. structure and parameters of the AFNC can be self-adaptive in the presence of disturbances to maintain high control performance; (6) Robust control, i.e. asymptotic stability of the control system is established using Lyapunov theorem. Computer simulation studies were carried out and comparison of simulation results with some existing controllers demonstrate the flexibility, adaptability and good tracking performance of the proposed controller.
Gouache TP, Gao Y, Frame T, Coste P, Gourinat Y (2011) Identification of the forces between regolith and a reciprocating drill-head : perspectives for the exploration of Martian Regolith,
Er MJ, Gao Y (2003) Online Adaptive Fuzzy Neural Identification and Control of Nonlinear Dynamic Systems, In: Zhou C, Maravall D, Ruan D (eds.), Autonomous robotic systems pp. 373-402 Physica Verlag
This book contains an edited collection of eighteen contributions on soft and hard computing techniques and their applications to autonomous robotic systems.
Gao Y, Er MJ (2003) Online adaptive fuzzy neural identification and control of a class of MIMO nonlinear systems, IEEE TRANSACTIONS ON FUZZY SYSTEMS 11 (4) pp. 462-477 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Al-Milli S, Spiteri C, Comin F, Gao Y (2013) Real-time Vision Based Dynamic Sinkage Detection for Exploration Rovers,
Identification of the wheel sinkage of exploration rovers provides valuable insight into the characteristics of deformable soils and thus the ease of traversal is also identified. In this paper we propose a simple vision based approach that robustly detects and measures the sinkage of any shaped wheel in real-time and with little sensitivity to various operating conditions. The method is based on color-space segmentation to identify the wheel contour and consequently the depth of the sinkage. In addition, our approach also provides a dynamic sinkage analysis which potentially allows for the identification of non-geometric hazards. The robustness of the algorithm has been validated for poor lighting, blurring, and background noise. The experimental results presented are for a hybrid legged wheel from our in-house single-wheel test-bed.
Gao Y, Ellery A (2006) Autonomous Navigation Based on Optic Flow for ExoMars Rovers, Proceedings of AISB'06: Adaptation in Artificial and Biological Systems 2
Gao Y, Samperio R, Shala K, Cheng Y (2012) Modular Design for Planetary Rover Autonomous Navigation Software using ROS, Acta Futura (5) 1 pp. 9-16 European Space Agency
?is paper presents a modular design
concept of autonomous navigation software
for planetary rovers. ?e software covers major
navigation functions such as autonomous localisation
and mapping, visual rock detection, and
path planning. ?e proposed design includes a
generic data pipeline which produces a sequence
of data products based on sensory raw data. To
effectively and efficiently integrate the various design
elements, Robot Operating System (known
as ROS) is used as the middleware framework to
implement the generic data pipeline and synthesize
various navigation functions in terms of ROS
nodes. ?e paper also presents test results of the
proposed software implemented within the Surrey
Rover Autonomous Software and Hardware
Testbed (SMART) based on real and artificial data.
Gao Y, Spiteri C, Pham M-T, Al-Milli S (2013) A survey on recent object detection techniques useful for monocular vision-based planetary terrain classification, Robotics and Autonomous Systems
Direct terrain classification from monocular images for autonomous navigation of planetary rovers is a relatively new and challenging research area, not only because of the hardware limitation of a rover, but also because the rocks and obstacles to be detected exhibit diverse morphologies and have no uniform properties to distinguish them from background soil. We present a survey of recently developed object detection techniques that can be useful for terrain classification for planetary rovers. We start with summarizing current vision-based terrain classification methods. We then provide a comprehensive and structured overview of recent object detection techniques, focusing on those applicable to terrain classification. Crown Copyright © 2013.
Gao Y, Phipps A, Taylor M, Clemmet J, Parker D, Crawford I, Ball A, Wilson L, Curiel A, Davies P, Sweeting M, Baker A (2007) UK Lunar Science Missions: MoonLITE & Moonraker,
Liu J, Gao Y, Wang Y, Ma S, Luo Y (2015) Comments on "sidewinding with minimal slip: snake and robot ascent of sandy slopes", Jiqiren/Robot 37 (2) pp. 254-256
©, 2015, Chinese Academy of Sciences. All right reserved.Marvi et al (Science, 2014, vol.346, p.224) concluded a sidewinder rattlesnake increases the body contact length with the sand when granular incline angle increases. They also claimed the same principle should work on robotic snake too. We have evidence to prove that this conclusion is only partial in describing the snake body-sand interaction. There should be three phases that fully represent the snake locomotion behaviors during ascent of sandy slopes, namely lifting, descending, and ceasing. The snake body-sand interaction during the descending and ceasing phases helps with the climbing while such interaction during the lifting phase in fact contributes resistance.
Spiteri C, Shaukat A, Gao Y (2016) Structure Augmented Monocular Saliency for Planetary Rovers, Robotics and Autonomous Systems 88 (Feb) pp. 1-10 Elsevier
This paper proposes a novel object detection method based on the visual saliency model in order to reliably detect objects such as rocks from single monocular planetary images. The algorithm takes advantage of the relatively homogeneous and distinct albedos present in planetary environments such as Mars or the Moon to extract a Digital Terrain Model of a scene using photoclinometry. The Digital Terrain Model is then incorporated into a bottom-up visual saliency algorithm to augment objects that protrude out of the ground. This Structure Augmented Monocular Saliency algorithm (SAMS) improves the accuracy and reliability of detecting objects in a planetary environment with no training requirements, greater robustness and lower computational complexity than 3D saliency models. Comprehensive analysis of the proposed method is performed using three challenging benchmark datasets. The results show that the Structure Augmented Monocular Saliency (SAMS) algorithm performs better than against commonly used visual saliency models on the same datasets
Chanik AB, Gao Y, Si J (2016) Modular testbed for spinning spacecraft, AIAA Journal of Spacecraft, and Rockets 54 (1) pp. 90-100 American Institute of Aeronautics and Astronautics
The ground verification of a spacecraft control algorithm is commonly done via air bearing facility. Air bearing testbeds are frequently developed for testing a three-axis stabilized spacecraft control algorithm but hardly for a spin-stabilized spacecraft. A modular testbed for testing a spinning spacecraft has been developed at Surrey Space Centre initially for the real-time verification of a prolate spinner slew control algorithm. This testbed is made from commercial off-the-shelf components with a modular system design approach through rapid control prototyping using Matlab xPC Target and is extendable to other rapid control prototyping techniques. It is equipped with a novel low-cost monocular vision system for attitude determination with accuracy of 0.06 deg and angular velocity accuracy of 0.15 deg/s0.15 deg/s. For the current specification, a cold-gas propulsion system is fixed to the testbed with a two-degree-of-freedom thruster set that can deliver up to 0.25 N of thrust and an air bearing capability that gives three degrees of freedom with a maximum tilt angle of 30 deg. In this paper, the testbed implementation is described, and the test platform is verified.
Kömle N, Pitcher CW, Gao Y, Richter L (2016) Study of the Formation of Duricrusts on the Martian Surface and Their Effect on Sampling Equipment, Icarus 281 pp. 220-227 Elsevier
The Powdered Sample Dosing and Distribution System (PSDDS) of the ExoMars rover will be required to handle and contain samples of Mars regolith for long periods of time. Cementation of the regolith, caused by water and salts in the soil, results in clumpy material and a duricrust layer forming on the surface. It is therefore possible that material residing in the sampling system may cement, and could potentially hinder its operation. There has yet to be an investigation into the formation of duricrusts under simulated Martian conditions, or how this may affect the performance of sample handling mechanisms. Therefore experiments have been performed to create a duricrust and to explore the cementation of Mars analogues, before performing a series of tests on a qualification model of the PSDDS under simulated Martian conditions.It was possible to create a consolidated crust of cemented material several millimetres deep, with the material below remaining powder-like. It was seen that due to the very low permeability of the Montmorillonite component material, diffusion of water through the material was quickly blocked, resulting in a sample with an inhomogeneous water content. Additionally, samples with a water mass content of 10% or higher would cement into a single solid piece. Finally, tests with the PSDDS revealed that samples with a water mass content of just 5% created small clumps with significant internal cohesion, blocking the sample funnels and preventing transportation of the material. These experiments have highlighted that the cementation of regolith in Martian conditions must be taken into consideration in the design of sample handling instruments.
Gao Y, Spiteri CC, Li C, Zheng Y (2016) Lunar soil strength estimation based on Chang?E-3 images, Advances in Space Research 58 (9) pp. 1893-1899 Elsevier
Chang?E-3 (CE-3) was the third mission by China to explore the Moon which had landed two spacecraft, the CE-3 lander and Yutu rover on the lunar surface in late 2013. The paper presents analytical results of high-resolution terrain data taken by CE-3?s onboard cameras. The image data processing aims to extract sinkage profiles of the wheel tracks during the rover traverse. Further analysis leads to derivation or estimation of lunar soil physical properties (in terms of strength and stiffness) based on the wheel sinkage, despite the fact Yutu does not possess in situ soil measurement instruments. Our findings indicate that the lunar soil at the CE-3 landing site has similar stiffness to what is measured at the Luna 17 landing site but has much less strength compared to the Apollo 15 landing site.
Gao Y, Chien S (2017) Review on space robotics: Toward top-level science through space exploration, Science Robotics 2 (7) American Association for the Advancement of Science
Robotics and autonomous systems have been instrumental to space exploration by enabling scientific breakthroughs
and by fulfilling human curiosity and ambition to conquer new worlds. We provide an overview of space
robotics as a rapidly emerging field, covering basic concepts, definitions, historical context, and evolution. We
further present a technical road map of the field for the coming decades, taking into account major challenges
and priorities recognized by the international space community. Space robotics represents several key enablers
to a wide range of future robotic and crewed space missions as well as opportunities for knowledge and technology
transfer to many terrestrial sectors. In the greater humanitarian context, space robotics inspires both current
and future generations to exploration and critical study of science, technology, engineering, and mathematics.
Firstbrook D, Worrall K, Timoney R, Suñol F, Gao Y, Harkness P (2017) An experimental study of ultrasonic vibration and the penetration of granular material, Proceedings of the Royal Society A 473 (2198) The Royal Society
This work investigates the potential use of direct ultrasonic vibration as an aid to penetration of granular material. Compared with non-ultrasonic penetration, required forces have been observed to reduce by an order of magnitude. Similarly, total consumed power can be reduced by up to 27%, depending on the substrate and ultrasonic amplitude used. Tests were also carried out in high-gravity conditions, displaying a trend that suggests these benefits could be leveraged in lower gravity regimes.
Nevatia Y, Bulens F, Gancet J, Gao Y, Al-Milli S, Sonsalla R, Kaupisch T, Fritsche M, Vögele T, Allouis E, Skocki K, Ransom S, Saaj CM, Matthews MC, Yeomans B, Richter L (2013) Safe Long?RangeTravel for Planetary Rovers through Forward Sensing, ESA Publications Division
Extra-terrestrial Planetary rover systems are uniquely remote, placing
constraints in regard to communication, environmental uncertainty, and
limited physical resources, and requiring a high level of fault tolerance
and resistance to hardware degradation.
This thesis presents a novel self-reconfiguring autonomous software architecture
designed to meet the needs of extraterrestrial planetary environments.
At runtime it can safely reconfigure low-level control systems,
high-level decisional autonomy systems, and managed software
architecture. The architecture can perform automatic Verification and
Validation of self-reconfiguration at run-time, and enables a system to be
self-optimising, self-protecting, and self-healing. A novel self-monitoring
system, which is non-invasive, efficient, tunable, and autonomously deploying,
is also presented.
The architecture was validated through the use-case of a highly autonomous
extra-terrestrial planetary exploration rover. Three major
forms of reconfiguration were demonstrated and tested: first, high level
adjustment of system internal architecture and goal; second, software
module modification; and third, low level alteration of hardware control
in response to degradation of hardware and environmental change. The
architecture was demonstrated to be robust and effective in a Mars sample
return mission use-case testing the operational aspects of a novel,
reconfigurable guidance, navigation, and control system for a planetary
rover, all operating in concert through a scenario that required reconfiguration
of all elements of the system.
Future Mars exploration missions will have increasingly ambitious goals compared to current rover and lander missions. There will be a need for extremely long distance traverses over shorter periods of time. This will allow more varied and complex scientific tasks to be performed and increase the overall value of the missions. The missions may also include a sample return component, where items collected on the surface will be returned to a cache in order to be returned to Earth, for further study. In order to make these missions feasible, future rover platforms will require increased levels of autonomy, allowing them to operate without heavy reliance on a terrestrial ground station. Being able to autonomously localise the rover is an important element in increasing the rover's capability to independently explore.

This thesis develops a Planetary Monocular Simultaneous Localisation And Mapping (PM-SLAM) system aimed specifically at a planetary exploration context. The system uses a novel modular feature detection and tracking algorithm called hybrid-saliency in order to achieve robust tracking, while maintaining low computational complexity in the SLAM filter. The hybrid saliency technique uses a combination of cognitive inspired saliency features with point-based feature descriptors as input to the SLAM filter. The system was tested on simulated datasets generated using the Planetary, Asteroid and Natural scene Generation Utility (PANGU) as well as two real world datasets which closely approximated images from a planetary environment. The system was shown to provide a higher accuracy of localisation estimate than a state-of-the-art VO system tested on the same data set.

In order to be able to localise the rover absolutely, further techniques are investigated which attempt to determine the rover's position in orbital maps. Orbiter Mask Matching uses point-based features detected by the rover to associate descriptors with large features extracted from orbital imagery and stored in the rover memory prior the mission launch. A proof of concept is evaluated using a PANGU simulated boulder field.

Si Juntian, Gao Yang, Chanik Abadi (2017) Feedback Slew Algorithms for Prolate Spinners Using Single?Thruster, Acta Astronautica 144 pp. 39-51 Elsevier
A number of low-cost open-loop slew control algorithms have been developed for prolate spinning spacecraft using single-thruster actuation. Robustness analysis indicates that these algorithms have high sensitiveness over thruster firing time error, spacecraft inertia error, and especially spin rate perturbations. This paper proposed two novel feedback slew algorithms, Feedback Half-Cone and Feedback Sector-Arc Slew, built on the existing open-loop algorithms and they use attitude and angular velocity feedback to improve robustness. As presented, after the first thruster actuation initiate the spin-axis precession, the feedback slew algorithms take attitude and spin-rate feedback to estimate the angular momentum and predict the spin-axis attitude during the slew. These techniques contribute to improve the cancelation thrust impulse accuracy and reduce the final nutation error. Simulations for a Penetrator mission scenario validate these feedback algorithms and show their slew performance and robustness over the perturbations mentioned above. It is proved that the attitude feedback greatly improves the slew accuracy and robustness.
Passive spacecraft attitude control using spin-stabilization is considered as one of traditional and low-cost control strategies. In literature, low-cost state-of-the-art slew algorithms based on single thruster are designed to perform large angle spin axis attitude manoeuvre. The existing research and analysis shows that half-cone category algorithms are open-loop slew control and they are sensitive to spin rate perturbation. In order to improve the tolerance of spin-rate perturbations, the work is motivated to introduce closed-loop attitude feedback using sensors.
For nano-satellites, especially for cubesat missions, thrusters are restricted to its size and propellant consumption, so thrusters are not usually chosen as the actuators on nano-satellites. Alternatively, other actuators such as magnetorquers and momentum wheels are feasible in nano-satellite missions. For nano-satellite missions, a novel low-cost slew control algorithm using single-magnetorquer is investigated based on the philosophy of single-thruster slew algorithms.
This thesis gives an overview of the research on single actuator control of a prolate spin-stabilised around its minimum moment of inertia axis. Two novel feedback slew algorithms using single-thruster have been developed. Thorough robustness analyses have been performed to estimate how well these novel algorithms perform in the presence of spin-rate disturbances compared with co-responding open-loop algorithms. The results of these analyses indicate that with the help of attitude feedback, these feedback slew algorithms show more robust performance compared with their corresponding open-loop algorithms.
A feedback slew algorithm using single-magnetorquer has also been developed based on Half-Cone slew philosophy using single-thruster, dealing with large angle attitude manoeuvre problem where magnetorquer is applied for the mission. Simulations based on STRaND-1, a 3-U cubesat launched by Surrey Space Centre and Surrey Satellite Technology Ltd., was chosen as a use case to simulate attitude manoeuvres parallel with Earth equatorial plane. These manoeuvres were carried out at different orbital positions.
To conclude, the research presented in this thesis has led to two novel slew algorithms using single-thruster and thorough analysis proves that these algorithms greatly improve the robustness on spin-rate perturbations. A feedback algorithm using single-magnetorquer has also been developed dealing with large angle attitude manoeuvre problem. Future directions for research in this area is also recommended.
Nanjangud S, Blacker P, Bandyopadhyay S, Gao Y (2018) Robotics and AI-Enabled On-Orbit Operations With Future Generation of Small Satellites, Proceedings of the IEEE 106 (3) pp. 429-439 Institute of Electrical and Electronics Engineers (IEEE)
The low-cost and short-lead time of small satellites
has led to their use in science-based missions, earth observation,
and interplanetary missions. Today, they are also key instruments
in orchestrating technological demonstrations for on-orbit
operations (O3) such as inspection and spacecraft servicing with
planned roles in active debris removal and on-orbit assembly.
This paper provides an overview of the robotics and autonomous
systems (RASs) technologies that enable robotic O3 on smallsat
platforms. Major RAS topics such as sensing & perception,
guidance, navigation & control (GN&C) microgravity mobility
and mobile manipulation, and autonomy are discussed from the
perspective of relevant past and planned missions.
Proenca P, Gao Y (2018) SPLODE: Semi-probabilistic point and line odometry with depth estimation from RGB-D camera motion, 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) pp. 1594-1601 Institute of Electrical and Electronics Engineers (IEEE)
Active depth cameras suffer from several limitations, which cause incomplete and noisy depth maps, and may consequently affect the performance of RGB-D Odometry. To address this issue, this paper presents a visual odometry method based on point and line features that leverages both measurements from a depth sensor and depth estimates from camera motion. Depth estimates are generated continuously by a probabilistic depth estimation framework for both types of features to compensate for the lack of depth measurements and inaccurate feature depth associations. The framework models explicitly the uncertainty of triangulating depth from both point and line observations to validate and obtain precise estimates. Furthermore, depth measurements are exploited by propagating them through a depth map registration module and using a frame-to-frame motion estimation method that considers 3D-to-2D and 2D-to-3D reprojection errors, independently. Results on RGB-D sequences captured on large indoor and outdoor scenes, where depth sensor limitations are critical, show that the combination of depth measurements and estimates through our approach is able to overcome the absence and inaccuracy of depth measurements.
Proenca P, Gao Y (2018) Probabilistic RGB-D odometry based on points, lines and planes under depth uncertainty, Robotics and Autonomous Systems Elsevier
This work proposes a robust visual odometry method for structured environments that combines point features with line and plane segments, extracted through an RGB-D camera. Noisy depth maps are processed by a probabilistic depth fusion framework based on Mixtures of Gaussians to denoise and derive the depth uncertainty, which is then propagated throughout the visual odometry pipeline. Probabilistic 3D plane and line fitting solutions are used to model the uncertainties of the feature parameters and pose is estimated by combining the three types of primitives based on their uncertainties.

Performance evaluation on RGB-D sequences collected in this work and two public RGB-D datasets: TUM and ICL-NUIM show the benefit of using the proposed depth fusion framework and combining the three feature-types, particularly in scenes with low-textured surfaces, dynamic objects and missing depth measurements.

Pitcher C, Gao Y (2018) Physical Properties of Icy Materials, In: Badescu V, Zacny K (eds.), Outer Solar System: Prospective Energy and Material Resources Springer International Publishing
Saunders C, Lobb D, Sweeting M, Gao Y (2017) Building large telescopes in orbit using small satellites, Acta Astronautica 141 pp. 183-195 Elsevier
In many types of space mission there is a constant desire for larger and larger instrument apertures, primarily for the purposes of increased resolution or sensitivity. In the Radio Frequency domain, this is currently addressed by antennas that unfold or deploy on-orbit. However, in the optical and infrared domains, this is a significantly more challenging problem, and has up to now either been addressed by simply having large monolithic mirrors (which are fundamentally limited by the volume and mass lifting capacity of any launch vehicle) or by complex ?semi-folding? designs such as the James Webb Space Telescope. An alternative is to consider a fractionated instrument which is launched as a collection of individual smaller elements which are then assembled (or self-assemble) once in space, to form a much larger overall instrument. SSTL has been performing early concept assessment work on such systems for high resolution science observations from high orbits (potentially also for persistent surveillance of Earth). A point design of a 25 m sparse aperture (annular ring) telescope is presented. Key characteristics of 1) multiple small elements launched separately and 2) on-orbit assembly to form a larger instrument are included in the architecture. However, on-orbit assembly brings its own challenges in terms of guidance navigation and control, robotics, docking mechanisms, system control and data handling, optical alignment and stability, and many other elements. The number and type of launchers used, and the technologies and systems used heavily affect the outcome and general cost of the telescope. The paper describes one of the fractionated architecture concepts currently being studied by SSTL, including the key technologies and operational concepts that may be possible in the future.
Vision based object detection is a key feature within planetary rover navigation
which facilitates several functions such as hazard avoidance, localization and path
planning. Most of the current research is based on stereoscopic vision or multiple cameras
strategically placed along the rover chassis that perform one specific function. This
works for large rovers with sufficient processing power, however such resources would
not be very practical for small or micro-rovers.
This thesis aims to extract terrain surface information from a single camera mounted
on a micro-rover such as the Surrey Mobile Autonomy and Robotics Testbed (SMART)
based on minimal computational resources. The terrain surface information can provide
feature inputs to other on-board navigation functions such as the Planetary Monocular
Simultaneous Localisation and Mapping (PM-SLAM) and constellation matching.
The detected terrain surface can also be of scientific interest due of the geometrical
characteristics produced from this research.
This research aims to improve the processing speed of the Guidance Navigation
and Control (GNC) system using low level 2D image processing techniques. The methods
employed result in a faster "perception stage" of the GNC with lower processing
power requirements, creating structural information, shape descriptors and cognitive
segmentation/classification of the rover?s surrounding environment.
Although the initial application of this research is for planetary rovers, the research
outcome is envisaged to be relevant, and hence transferable, to other vehicle navigation
problems used on land, air or under water.
Kruzelecky Roman, Murzionak Piotr, Lavoie Jonathan, Sinclair Ian, Schinn Gregory, Underwood Craig, Gao Yang, Bridges Christopher, Armellin Roberto, Luccafabris Andrea, Cloutis Edward, Leijtens Johan (2018) VMMO Lunar Volatile and Mineralogy Mapping Orbiter, International Conference on Environmental Systems Proceedings 2018 MPB Communications Inc.
Understanding the lunar near-surface distribution of relevant in-situ resources, such as ilmenite (FeTiO3), and volatiles, such as water/ice, is vital to future sustained manned bases. VMMO is a highly-capable, low-cost 12U Cubesat designed for operation in a lunar frozen orbit. It accomodates the LVMM Lunar Volatile and Mineralogy Mapper and the CLAIRE Compact LunAr Ionising Radiation Environment payloads. LVMM is a multi-wavelength Chemical Lidar using fiber lasers emitting at 532nm and 1560nm, with an optional 1064nm channel, for stand-off mapping of the lunar ice distribution using active laser illumination, with a focus on the permanently-shadowed craters in the lunar south pole. This combination of spectral channels can provide sensitive discrimination of water/ice in various regolith. The fiber-laser technology has heritage in the ongoing Fiber Sensor Demonstrator flying on ESA's Proba-2. LVMM can also be used in a low-power passive mode with an added 280nm UV channel to map the lunar mineralogy and ilmenite distribution during the lunar day using the reflected solar illumination. CLAIRE is designed to provide a highly miniaturized radiation environment and effect monitor. CLAIRE draws on heritage from the MuREM and RM payloads, flown on the UK?s TDS-1 spacecraft. The payload includes PIN-diode sensors to measure ionizing particle fluxes (protons and heavy-ions) and to record the resulting linear energy transfer (LET) energy-deposition spectra. It also includes solid-state RADFET dosimeters to measure accumulated ionizing dose, and dose-rate diode detectors, designed to respond to a Coronal Mass Ejection (CME) or Solar Particle Event (SPE). CLAIRE also includes an electronic component test board, capable of measuring SEEs and TID effects in a selected set of candidate electronics, allowing direct correlations between effects and the real measured environment.
Bergman JES, Bridges Christopher, Bruhn F, Gao Yang, Lappas V, Liddle D, Mouginis-Mark P, Nunes M, Palmer P, Sorensen T, Underwood Craig (2014) Characterizing the RF Quiescence of the Lunar Far Side Using a Constellation of Small Satellites, EPSC Abstracts; European Planetary Science Congress 2014 9 European Planetary Science Congress
Observations of highly red-shifted 21-cm hydrogen signals have been suggested as the only means to probe the early Universe from recombination to reionization. During this era, called the Dark Ages, the Universe consisted of neutral hydrogen gas and was opaque to light. It did not become transparent, as we see it today, until reionization was completed. The Dark Ages was the time period when matter clumped together, the very first stars and black holes were born, and, eventually, the first galaxies were formed. To enable observations of the Dark Ages is therefore one of the top priorities in cosmology and astrophysics. Today, the cosmological 21-cm signals are highly red-shifted and should peak in the FM radio band. Observing the Dark Ages from Earth is therefore next to impossible, due to man-made radio frequency interference (RFI) and ionospheric disturbances. To efficiently block the RFI, which would otherwise overwhelm the weak cosmological signal; it has been proposed to use the Moon as a radio shield and either place a satellite equipped with an ultra-sensitive radio instrument in lunar orbit or to deploy a large low-frequency radio array on the far-side of the Moon. Such missions are technically challenging and expensive and have so far failed to gain support from any national or international space program. Our goal is therefore to use a constellation of small inexpensive satellites in lunar orbit to collect pathfinder data, which would demonstrate EPSC Abstracts Vol. 9, EPSC2014-798, 2014 European Planetary Science Congress 2014 c Author(s) 2014 EPSC European Planetary Science Congress the feasibility of using the Moon as a radio shield, and map out the spatial extent of this RF quiescent zone to support future missions to explore the cosmos. This paper examines the design and radio payload of this mission. Alternative orbits, constellation and payload designs are analyzed to optimize the mission for performance and cost.