Experimental Research on PMSM Ball Screw Actuator and Structural Design Suggestion of Featured Active Suspension

Aiming to develop a practical active suspension, a PMSM ball screw actuator prototype is manufactured and experimented for parameter identification. Based on identification results, a new double-vibration-reduction-structure for the featured active suspension is proposed to cope with the problem caused by the actuator's overlarge equivalent inertial mass. Unlike using a resistance to absorb output energy of the actuator, a method of varying charge voltage in steps is utilized to reclaim vibration energy into the battery pack directly. The mechanical and energy-regenerative characteristics are tested for verification of the marked parameters and identification of the unmarked parameters, especially for the Coulomb damping and the equivalent inertial mass of the actuator prototype. Besides, a high energy-regenerative efficiency and a large capability of electromagnetic control force are achieved, the overlarge equivalent inertial mass exists. To reduce the amplified demand of the active control force caused by the actuator's overlarge equivalent inertial mass directly exposed to the unsprung mass acceleration, the new double-vibration-reduction-structure (DVRS) based active suspension structure scheme suggestion with an added-vibration-reduction-structure (AVRS) between the actuator and the unsprung mass is proposed. Regulated by the corresponding LQG controller, the proposed active suspension can achieve almost the same performance of the conventional ideal active suspension.