A systems approach to controlled heavy vehicle suspensions

This paper considers the design of a vehicle dynamics control system to control a tractor - semi-trailer vehicle fitted with active anti-roll hardware and semi-active ride suspension units. Key items of the system specification are discussed. The configuration of processors is considered, as are key issues of CPU requirements and communications. For reasons of reliability, safety, coding simplicity and modularity, a system of local controllers connected via a CAN bus to a global controller was selected. Details of this implementation, including safety precautions such as a vehicle dynamics watchdog, sensor consistency checks, localised processor watchdogs and a hardwired stop system are also discussed. Application to all areas of vehicle dynamics data collection and control is looked at.