A theoretical investigation of a prototype active roll control system

This paper describes a simulation study conducted as part of the development of a hydraulic active roll control suspension. The system is based upon roll bars with integral closed loop position controlled hydraulic rotary actuators supplied with flow by a single proportional valve. A theoretical analysis of the fundamental characteristics of the system is presented together with the simulation implementation. System performance is examined, parameter sensitivity studies are undertaken and a number of practical measures to enhance performance are considered. The roll control system was largely insensitive to hydraulic system changes, control valve bandwidth being the most important parameter. Speed dependent gain scheduling of the forward path actuation system roll moment controller was shown to partially overcome the problem of vehicle dynamics which change with forward speed. A comparison of actuator displacement and actuator differential pressure feedback systems demonstrated that while the roll control performance of the former system was superior, the ride performance was inferior.