Direct Torque Control for Electronic Differential in an Electric Racing Car
This paper presents a new method for development of electronic differentials for electric racing vehicles. Most electronic differential solutions focus on maintaining the vehicle stability as the first and dominant priority, and are designed to keep some stability-related quantity (e.g. wheel slip) in a “safe region”. With racing cars however, the main focus is on the responsiveness of the vehicle and its capability to cope with extreme steering and accelerating demands from the driver. Our focus is on designing a controller to achieve neutral-steer (avoiding over- or under-steer) in race car driving conditions. We show a direct relationship between the steering condition and the difference of the longitudinal tire-road friction forces for the driven wheels. We mathematically derive the desired difference in the tire-road frictions that would achieve neutral-steer and show that it is directly related to the difference in the driving torques provided by motors. A closed-loop-control system is proposed for direct control of the motor torques. The simulation results show a close-to-neutral steering performance of the car (while maintaining its stability) in challenging steering scenarios.
KeywordsMotor Torque Slip Ratio Drive Wheel Direct Torque Control Vehicle Stability
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- 1.Magallan, G.A., et al.: A neighborhood electric vehicle with electronic differential traction control. In: 34th Annual Conference of the IEEE Industrial Electronics Society, IECON 2008, Orlando, FL, United states, pp. 2757–2763 (2008)Google Scholar
- 3.Kim, J., Kim, H.: Electric vehicle yaw rate control using independent in-wheel motor. In: 4th Power Conversion Conference-NAGOYA, PCC-NAGOYA 2007, Nagoya, Japan, pp. 705–710 (2007)Google Scholar
- 5.Li, J., et al.: Electronic differential control with vehicle state observer based on Extended Kalman Filter. In: 2011 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring, CDCIEM 2011, Changsha, Hunan, China, pp. 172–175 (2011)Google Scholar