Faults and their influence on the dynamic behaviour of electric vehicles

The increase of electronics in road vehicles comes along with a broad variety of possibilities in terms of safety, handling and comfort for the users. A rising complexity of the vehicle subsystems and components accompanies this development and has to be managed by increased electronic control. More potential elements, such as sensors, actuators or software codes, can cause a failure independently or by mutually influencing each other. There is a need of a structured approach to sort the faults from a vehicle dynamics stability perspective. This thesis tries to solve this issue by suggesting a fault classification method and fault tolerant control strategies. Focus is on typical faults of the electric driveline and the control system, however mechanical and hydraulic faults are also considered. During the work, a broad failure mode and effect analysis has been performed and the faults have been modeled and grouped based on the effect on the vehicle dynamic behaviour. A method is proposed and evaluated, where faults are categorized into different levels of controllability, i. e. levels on how easy or difficult it is to control a fault for the driver, but also for a control system. Further, fault-tolerant control strategies are suggested that can handle a fault with acritical controllability level. Two strategies are proposed and evaluated based on the control allocation method and an electric vehicle with typical faults. It is shown that the control allocation approaches give less critical trajectory deviation compared to no active control and a regular Electronic Stability Control algorithm. To conclude, this thesis work contributes with a methodology to analyse and develop fault-tolerant solutions for electric vehicles with improved traffic safety.

Language

  • English

Media Info

  • Pagination: 70
  • Serial:
    • TRITA-AVE
    • Issue Number: 2013:48
    • Publisher: KTH Royal Institute of Technology, Sweden
    • ISSN: 1651-7660

Subject/Index Terms

Filing Info

  • Accession Number: 01575413
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Files: ITRD, VTI
  • Created Date: Sep 1 2015 11:21AM