Ahu Hartavi Karci

Dr Ahu Ece Hartavi Karci

Senior Lecturer in Automotive Engineering
+44 (0)1483 682895
16A AA 03

Academic and research departments

Department of Mechanical Engineering Sciences.



In the media

Formula Student UK 2019 Competition @SilverstoneCircuit 
e-Formula Student 2019 Coordinator


Research interests

My publications


Hartavi Karci A, Can Uygan IM, Güvenç L (2016) A hybrid electric vehicle hardware-in-the-loop simulator as a development platform for energy management algorithms, International Journal of Vehicle Design 71 (1-4) pp. 410-428 Inderscience Enterprises Ltd.
The aim of an effective hybrid electric vehicle (HEV) energy management strategy is to reduce fuel consumption and undesired pollutant emission levels while maintaining drivability and battery state of charge (SOC). A high-fidelity laboratory test platform that enables verification, validation and testing of the strategy developed in the shortest possible time is essential for the demanded quality and performance levels. This paper presents a hardware-in-the-loop simulator developed for the evaluation of HEV energy management algorithms (EMAs). The hardware in the loop (HiL) simulation model of a front and rear wheel electric motor driven hybrid electric commercial van with an internal combustion engine powering the front wheels is presented. The EMA used in the platform is also introduced. Finally, HiL simulation results are compared with road test results to demonstrate the effectiveness of the proposed approach.
Güvenç L, Uygan IMC, Kahraman K, Karaahmetoglu R, Altay I, Sentürk M, Emirler MT, Hartavi Karci AE, Aksun Güvenç B, Altug E, Turan MC, Tas OS, Bozkurt E, Özgüner U, Redmill K, Kurt A, Efendioglu B (2012) Cooperative Adaptive Cruise Control Implementation of Team Mekar at the Grand Cooperative Driving Challenge,IEEE Transactions on Intelligent Transportation Systems
This paper presents the cooperative adaptive cruise control implementation of Team Mekar at the Grand Cooperative Driving Challenge (GCDC). The Team Mekar vehicle used a dSpace microautobox for access to the vehicle controller area network bus and for control of the autonomous throttle intervention and the electric-motor-operated brake pedal. The vehicle was equipped with real-time kinematic Global Positioning System (RTK GPS) and an IEEE 802.11p modem installed in an onboard computer for vehicle-to-vehicle (V2V) communication. The Team Mekar vehicle did not have an original-equipment-manufacturer-supplied adaptive cruise control (ACC). ACC/Cooperative adaptive cruise control (CACC) based on V2V-communicated GPS position/velocity and preceding vehicle acceleration feedforward were implemented in the Team Mekar vehicle. This paper presents experimental and simulation results of the Team Mekar CACC implementation, along with a discussion of the problems encountered during the GCDC cooperative mobility runs.
Vacca F, Pinto De S, Hartavi Karci A, Gruber P, Viotto F, Cavallino C, Rossi J, Sorniotti A (2017) On the Energy Efficiency of Dual Clutch
Transmissions and Automated Manual Transmissions
Energies 10 (10) 1562 pp. 1-22 MDPI
The main benefits of dual clutch transmissions (DCTs) are: (i) a higher energy efficiency
than automatic transmission systems with torque converters; and (ii) the capability to fill the torque
gap during gear shifts to allow seamless longitudinal acceleration profiles. Therefore, DCTs are viable
alternatives to automated manual transmissions (AMTs). For vehicles equipped with engines that
can generate considerable torque, large clutch-slip energy losses occur during power-on gear shifts
and, as a result, DCTs need wet clutches for effective heat dissipation. This requirement substantially
reduces DCT efficiency because of the churning and ancillary power dissipations associated with
the wet clutch pack. To the knowledge of the authors, this study is the first to analyse the detailed
power loss contributions of a DCT with wet clutches, and their relative significance along a set of
driving cycles. Based on these results, a novel hybridised AMT (HAMT) with a single dry clutch
and an electric motor is proposed for the same vehicle. The HAMT architecture combines the high
mechanical efficiency typical of AMTs with a single dry clutch, with the torque-fill capability and
operational flexibility allowed by the electric motor. The measured efficiency maps of a case study
DCT and HAMT are compared. This is then complemented by the analysis of the respective fuel
consumption along the driving cycles, which is simulated with an experimentally validated vehicle
model. In its internal combustion engine mode, the HAMT reduces fuel consumption by >9% with
respect to the DCT.

The research of this thesis focuses on the hardware-in-the-loop (HIL) assessment of proof-of-concept automotive systems. Two main applications are investigated: i) hybridised drivetrains; and ii) novel wheel slip controllers for anti-lock braking systems (ABS) applications.

The activities related to the assessment of proof-of-concept transmissions involve preliminary simulations and experimental evaluation of novel transmission prototypes for high performance passenger cars. A model-based approach is used to analyse the main power loss contributions of a baseline case study transmission. The newly developed hybridised transmission offers comparable performance (i.e. smooth acceleration profile during gearshift events), addressing comfort requirements. The experimental activity showed the efficiency improvements due to the mechanical layout of the new hybridised transmission. The benefits deriving by the hybridisation are also assessed through simulations carried out considering alternative proof-of-concept transmission layouts and an on-line implementable energy management strategy (A-ECMS). Other examples of hybridization layouts are also reported, i.e., the very recently developed hybrid rear axle module (HRAM). Furthermore, because of its ?modular? nature, the device can be equipped with advanced mechanical systems which allow a left-to-right torque distribution.

The wheel slip controller assessment on a HIL test rig setup involves an electro-hydraulic braking (EHB) unit. Because of their decoupled nature, EHBs offer independent and continuous modulation of the pressure levels at the four corners of the vehicle. For this test case, the HIL methodology is employed to quantify the performance benefits deriving from a PID-based wheel slip controller and a more advanced control strategy such as an explicit non-linear model predictive controller (eNMPC). The eNMPC performs better with respect the PID-based wheel slip controller on different test case scenarios. The results obtained during the development process have proven the effectiveness of the presented devices.

Shao Lingyun, Hartavi Karci Ahu Ece, Tavernini Davide, Sorniotti Aldo, Cheng Ming (2020) Design Approaches and Control Strategies for Energy-Efficient Electric Machines for Electric Vehicles - A Review,IEEE Access Institute of Electrical and Electronics Engineers
The market penetration of electric vehicles (EVs) is going to significantly increase in the next
years and decades. However, EVs still present significant practical limitations in terms of mileage. Hence,
the automotive industry is making important research efforts towards the progressive increase of battery
energy density, reduction of battery charging time, and enhancement of electric powertrain efficiency. The
electric machine is the main power loss contributor of an electric powertrain. This literature survey reviews
the design and control methods to improve the energy efficiency of electric machines for EVs. The motor
design requirements and specifications are described in terms of power density, efficiency along driving
cycles, and cost, according to the targets set by the roadmaps of the main governmental agencies. The review
discusses the stator and rotor design parameters, winding configurations, novel materials, construction
technologies as well as control methods that are most influential on the power loss characteristics of typical
traction machines. Moreover, the paper covers: i) driving cycle based design methods of traction motors,
for energy consumption reduction in real operating conditions; and ii) novel machine topologies providing
potential efficiency benefits.

Additional publications