A novel approach to design and control of an active suspension using linear pump control-based hydraulic system

Abstract

This paper presents a novel design and control method of an active suspension system using a linear pump control-based hydraulic system for a cost-effective application. Various active suspension systems have been proposed and applied to vehicles due to its ability to improve ride comfort and handling performance even though these active suspension systems are not popular because of their complexity, high cost, heavyweight, and low power efficiency. A new type of active suspension actuator system was designed and validated herein based on the methods of actuator sizing and modified control scheme to address the aforementioned issues. System power capability has been analyzed under various dynamics and road conditions. Active suspension actuator components have been designed based on the results. The electro-hydraulic system is powered by a battery to reduce the energy consumption of the system; hence, it is operated by torque on demand. A double-acting linear hydraulic motor pump with a dual rack and pinion has been proposed for hydraulic force control with a simple on/off switch operation. The actuator force has been controlled by continuous linear motor pump displacement control via torque control using a three-phase synchronous brushless alternative current motor. Dynamic performance evaluation of the actuator system has been conducted using AMESIM and actual rig test. Active height and roll control algorithms for the enhancement of vehicle dynamics considering actuator dynamics have also been developed and validated through the rig and real vehicle tests. The evaluation results showed that the linear motor pump-based active suspension system performs as well as the previous complicated hydraulic active suspension system. The new active system proposed in this study was able to improve the vehicle dynamics using cost-effective actuation system significantly.