Dynamics characteristics analysis and control of FWID EV
Compared with internal combustion engine (ICE) vehicles, four-wheel-independently-drive electric vehicles (FWID EV) have significant advantages, such as more controlled degree of freedom (DOF), higher energy efficiency and faster torque response of an electric motor. The influence of these advantages and other characteristics on vehicle dynamics control need to be evaluated in detail. This paper firstly analyzed the dynamics characteristics of FWID EV, including the feasible region of vehicle global force, the improvement of powertrain energy efficiency and the time-delays of electric motor torque in the direct yaw moment feedback control system. In this way, the influence of electric motor output power limit, road friction coefficient and the wheel torque response on the stability control, as well as the impact of motor idle loss on the torque distribution method were illustrated clearly. Then a vehicle dynamics control method based on the vehicle stability state was proposed. In normal driving condition, the powertrain energy efficiency can be improved by torque distribution between front and rear wheels. In extreme driving condition, the electric motors combined with the electro-hydraulic braking system were employed as actuators for direct yaw moment control. Simulation results show that dynamics control which take full advantages of the more controlled freedom and the motor torque response characteristics improve the vehicle stability better than the control based on the hydraulic braking system of conventional vehicle. Furthermore, some road tests in a real vehicle were conducted to evaluate the performance of proposed control method.
KeywordsFour-wheel-independently-drive electric vehicles (FWID EV) Dynamics characteristics Powertrain energy efficiency Vehicle stability, Dynamics control
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- Hac, A. and Simpson, M. (2000). Estimation of vehicle sideslip angle and yaw rate. SAE Paper No. 2000-01-0696.Google Scholar
- Sawase, K. and Ushiroda, Y. (2008). Improvement of vehicle dynamics by right-and-left torque vectoring system in various drivetrains. Mitsubishi Technical Review 2008, 2, 14–20.Google Scholar
- Keiji, I. (1989). Effects on cornering characteristics by driven-force control. J. Society of Automotive Engineers of Japan 43, 4, 67–73.Google Scholar
- Keiji, I. (1990). Technical trends of driving-force control technology. J. Society of Automotive Engineers of Japan 44, 1, 76–84.Google Scholar
- Kim, W., Yi, K. and Lee, J. (2012). An optimal traction, braking, and steering coordination strategy for stability and manoeuvrability of a six-wheel drive and six-wheel steer vehicle. Proc. Institution of Mechanical Engineers, Part D: J. Automobile Engineering 226, 1, 3–22.Google Scholar
- Lu, D., Gu, J., Li, J., Ouyang, M. and Ma, Y. (2009). Highperformance control of PMSM based on a new forecast algorithm with only low-resolution position sensor. Vehicle Power and Propulsion Conf., IEEE, 1440–1444.Google Scholar
- Lv, C., Zhang, J., Li, Y., Sun, D. and Yuan, Y. (2014). Hardware-in-the-loop simulation of pressure-differencelimiting modulation of the hydraulic brake for regenerative braking control of electric vehicles. Proc. Institution of Mechanical Engineers, Part D: J. Automobile Engineering 228, 6, 649–662.CrossRefGoogle Scholar
- NHTSA (2007). Electronic Stability Control Systems. Federal Motor Vehicle Safety Standard 126.Google Scholar
- Yu, N. and Gong, Y. M. (2008). High dynamic performance speed control strategy of high density IPMSM for HEV application. Intelligent Control and Automation, 7th World Cong., 1588–1593.Google Scholar