High-Bandwidth Suspension Resonance Analysis of In-Wheel Motor Vehicle Using Multibody Dynamics

Vibration suppression control of vehicles is important for ride comfort. In vehicles electrification, the in-wheel motor as an actuator for vibration suppression has attracted attention as an alternative to active suspension systems. For controller design, it is necessary to figure out the characteristics of the system. However, the frequency response characteristics of the suspension with the in-wheel motor are not fully understood. A conventional and traditional quarter car model gives an expression of only two resonances of the suspension system. This paper reveals that the third resonance comes from the suspension bushing using multibody dynamics. The authors also perform a sensitivity analysis of the frequency responses for a set of bushing stiffnesses that may differ with the product lifetime. Lastly, the authors show a feedforward controller design example based on the model analysis.