In-situ steering can significantly improve the vehicle's maneuverability in
narrow spaces, especially suitable for extreme scenarios such as off-road
driving and professional operations. For distributed drive electric vehicles,
kinematics-based left and right wheel differential control and dynamics-based
vehicle yaw control can achieve in-situ steering, however, the two methods have
different effects on in-situ steering performance. This paper proposes a
kinematics-based distributed drive electric vehicle differential in-situ
steering control method, which first establishes the functional relationship
between the drive pedal and the expected yaw rate, so that the driver can adjust
the steering speed. The initial reference wheel speed is calculated from the
expected yaw rate, and the reference wheel speed is adjusted by feedback from
the actual and expected yaw rate errors to improve the tracking accuracy. On
this basis, the sliding mode control algorithm is used to calculate the required
wheel torque, and finally the differential movement is realized by applying
reverse drive torque to the wheels on both sides. The simulation results show
that on the road surface of 0.85, the lateral offset is increased by 15.7% but
the longitudinal offset is reduced by 64% compared with the PID control, and the
lateral offset is reduced by 98.6% and the longitudinal offset is reduced by
97.5% compared with the yaw rate PID control, the steering radius can be less
than 0.1m, which greatly improves the stability and accuracy of in-situ
steering.