Structure Design and Parameter Optimization of a Three-Function Integrated Actuator-Based Active Suspension System

This study presents an innovative paralleled spring and three-function (vibration isolation, absorption, and active reduction) integrated actuator (TFIA)-based active suspension system. This novel design significantly enhanced the high-frequency vibration reduction effect and minimized the demanded control force of rotary-motor-type active suspension. TFIA comprised a bushing spring, a suspension third mass, and a ball screw-motor assembly (BSMA) in series from bottom to up. Besides using the bushing spring to primarily suppress the input of wheel acceleration, TFIA adopted the suspension third mass to further absorb high-frequency vibration to BSMA. Based on the feedforward feedback linearization method, the full-information optimal sliding mode controller was designed by establishing the sliding mode manifold function to include the suspension structure and expected performance information. To balance performance improvement and easy installation, three schemes of structure and control parameters were proposed and compared. Results illustrated that the BSMA self-mass and visual mass scheme is more feasible. The effectiveness of TFIA in suppressing the body's high-frequency vibration and reducing the demanded control force was corroborated by simulation and hardware-in-the-loop experiments.