Parametric numerical study of electrohydraulic active suspension performance against passive suspension

A parametric numerical study for an active electro-hydraulic and passive automotive quarter-car suspensions is implemented. Performance comparison is carried out numerically using SIMULINK's Simscape library. Road, vehicle and suspension parameters were varied and their effect were shown. Those parameters are the bump’s shape, amplitude and frequency, sprung mass, spring stiffness and damping coefficient. The active control is proportional-integral-derivative. This technique is most suitable as it shows how varied parameters affect the system for the same control technique. Vibrational analysis was performed on the system. The details of the developed system with the analytical results are presented. The active suspension’s performance was always superior to the passive. The active performance decreases slightly while increasing the road input frequency and amplitude. Also its performance is found to be undependable on the sprung mass thus having high load carrying capacity. Changing spring stiffness and damping coefficients didn’t affect the active performance much. It is also concluded that the spring and damper in parallel to the hydraulic suspension don’t affect the active performance but only useful as failsafe option. Keywords: Active suspension, Passive suspension, Servo, Hydraulic, PID, Control, Electrohydrauli