Abstract:

This paper examines using electric vehicles with independently actuated wheels and anti-squat/lift/dive suspensions to improve passenger comfort by reducing the lift, pitch, and roll motion of the vehicle chassis. Anti-squat/lift/dive suspensions use an angled suspension bar to transfer a portion of the longitudinal driving force into a vertical reaction force on the chassis. Using this effect, we derive a control-oriented model of the lift, pitch, and roll of the chassis where the steering angle and the four driving forces of the individual wheels are the control inputs and the road-height is a disturbance. The model is simplified under the assumption that the suspension deflections are small during normal, comfortable driving. Finally, we use steady-state analysis and open-loop simulations to provide intuition about the relationship between the driving forces and the chassis motions.