Performance Sensitivity of an Actively Damped Vehicle Suspension to Feedback Variation

Abstract

A two degree of freedom vehicle model is analyzed for its performance sensitivity as a function of the system’s feedback gains. Three measures of performance, namely, sprung mass isolation, suspension travel, and tire contact force variation are examined. The varied feedback gains are the spring stiffness, the passive damping coefficient, and the active damping coefficient. Both frequency response and RMS response of the performance variables are considered and surfaces are formed to examine output sensitivity to suspension feedback. The results show that RMS vehicle isolation is increased by both softening the suspension and adding active damping. RMS tire contact force is influenced mostly by passive damping and only marginally affected by active damping. Suspension stiffness is shown to have no influence suspension travel for the passive suspension modeled.