Ideal wheel acceleration curve for nonlinear model predictive control approach in anti-slip traction of battery electric vehicle

Abstract

Traction control for battery electric vehicles requires high dynamic performance during acceleration and deceleration driving, making vehicle whole-process stability paramount. This is especially difficult for preventing traction wheels from slipping against rapidly increasing electric motor torque, for which ground adhesion data is scant. In addition, fast torque response is one of the characteristics of the traction-electric motor, with reaction times on the order of milliseconds. Most research on vehicle system dynamics focuses on vehicle and wheel speeds as the system states, while relatively few studies adopt wheel acceleration to formulate the traction dynamics model. In this research, the wheel acceleration dynamics, ground traction observer, and ideal wheel acceleration curve are mainly discussed in order to solve the anti-slip traction issue. A wheel acceleration demand control approach using the nonlinear model predictive controller is designed to prevent traction wheels from slipping. The designed approach is downloaded to the vehicle control unit and validated under some actual conditions using the battery electric vehicle, achieving the practical application of the anti-skid traction control based on the electric motor torque.