Fault-Tolerant Over-Actuated Hybrid Electric Vehicles
The overall goal of this research work is to analyze the impact of failure modes (caused by electrical and other faults) and the degree of in-built fault-tolerance for different vehicle control strategies in hybrid electric and pure electric vehicles (HEV). Particular focus is set on concepts where propulsion power is obtained from light in-wheel motors at each wheel. The solutions will be depending on which forces do occur and which sensors and actuators are available. The vehicle control strategy will also be depending on actual type of failure mode. Finally, verifying measurements of the level of fault-tolerance for various vehicle control algorithms on a scaled-down and a full-scale prototype vehicle is planned.
Vehicles with electric drive trains and by-wire chassis systems provide potential improvements in terms of passenger safety, comfort and handling. With an increased level of electrification, the number of ways on how to influence the vehicle movement can also be increased; an electric machine can be used for providing tractive as well as braking forces. This leads to a higher level of functional integration applying combined forces in longitudinal, lateral, and vertical direction with each actuator, thus vehicle safety can be increased. With this higher level of electrification, the amount of possible failure modes that can occur during operation is growing as well. Therefore this research work is conducted to analyze the system dependability of HEVs and design new fault-tolerant solutions.
The overall goal of the project is to analyze the impact of failure modes (caused by electrical and other faults) and the degree of in-built fault-tolerance for different vehicle control strategies in electric and hybrid-electric drivelines. Particular focus is on concepts where propulsion power is obtained from light in-wheel motors at each wheel.
The researchers are putting particular focus on HEV concepts where the propulsion power is obtained from light in-wheel motors at each wheel. A broad collection of possible risks and failure modes that can occur in a HEV (and in a regular car) is conducted. These faults aremodelled in a high-fideligty vehicle simulation environment and analysed regarding their influence on the vehicle dynamic behaviour. Possible consequences for traffic safety are identified and a fault classification method is developed from these results. Hereby, the severity of the identified faults and the controllability of the affected vehicle can be determined. Depending on which sensors and actuators are available, vehicle control strategies on to how to compensate for the occurring faults are developed.
In a next step, verifying measurements of the level of fault-tolerance for various vehicle control algorithms on a scaled-down prototype vehicle are planned.
- D. Wanner, J. Edrén, O. Wallmark, M. Jonasson, L. Drugge and A. Stensson Trigell, "Fault-Tolerant Control of Electric Vehicles with In-Wheel Motors through Tyre-Force Allocation", in proceedings of the 11th International Symposium on Advanced Vehicle Control, 2012. ( link to publication )
- D. Wanner, A. Stensson Trigell, L. Drugge, and J. Jerrelind, “Survey on fault-tolerant vehicle design”, in proceedings of the 26th Electric Vehicle Symposium, 2012. ( link to publication and download poster (pdf 1.6 MB) and word cloud (png 164 kB) )
- D. Wanner, "Fault-Tolerant Over-Actuated Hybrid Electric Vehicles", KTH Transport Day,
Funding and project partners
The Swedish Hybrid Vehicle Centre (SHC) is a national competence centre for the development of electric and hybrid vehicles. It is an arena where Sweden’s automotive industry, leading universities and government agencies are collaborating on research and development that focuses on electric and hybrid vehicle technology. This research work is one of the SHC funded projects within the thematic area of system studies and tools focusing on diagnostics, energy management and optimised control of hybrid vehicles. The partners actively involved in this project are: