Coordinated Control of Active Steering and Differential Braking Using Extended Command Governor for Rollover Avoidance

This paper develops an Extended Command Governor (ECG) for coordinated control of active steering and differential braking to prevent a vehicle from rolling over when undergoing aggressive maneuvers. The ECG modifies commands to well-designed closed-loop systems when necessary to prevent constraint violations. In this paper, the ECG is applied to a nonlinear vehicle model to maintain the vehicle in a safe state. For rollover avoidance, the ECG is designed to intervene and modify the driver’s input steering and braking commands when it predicts these signals may be unsafe and cause violation of the Load Transfer Ratio constraint. Simulation results show that the ECG can successfully detect and correct the unsafe commands to prevent constraint violation. Moreover, the ECG also behaves less conservatively than a previous design that used active steering control only. Specifically, the ECG described in this work allows the vehicle trajectory to stay closer to the desired trajectory.