Integration of Active Suspension and Active Driveline to Ensure Stability While Improving Vehicle Dynamics

Most active control systems developed for passenger vehicles are developed as safety systems. These control systems usually focus on improving vehicle stability and safety while ignoring the effects on the vehicle driveability. While stability is the primary concern of these control systems the driveability of the vehicle is also an important consideration. An example of compromised driveability in a stability control system is brake based active yaw control. Brake based systems are very effective at stability control but can have a negative impact on the longitudinal dynamics of a vehicle. The objective of the vehicle control systems developed for the future will be to preserve vehicle driveability while ensuring the stability of the vehicle. In this work, active suspension and active drivelines are developed as stability control systems that have a minimal impact on the driveability of the vehicle. The active control systems are developed as separate driveability and stability controls and then tested individually. Then the individual controls are integrated to create a multi-objective control system to improve driveability while maintaining stability. Enhancing driveability is a requirement but the primary goal of the controllers is to maintain stability. The controllers are tested with step steer and fishhook manoeuvres. Since many manoeuvres that require the intervention of a stability control system occur during evasive action, the controllers are tested at the limit handling conditions of the vehicle.