Viability of Differential Braking Based Steering Redundancy for an Autonomous Vehicle

Increasing demand for autonomous vehicles results in ever increasing research and development on safety-critical systems. This paper takes on the idea of using differential braking as a redundant steering system. The performance of the proposed method is tested using double lane change maneuvers. Two PID controllers are utilized to minimize the error between reference lateral position, yaw angle and system outputs. “Constant Velocity Offset Plus Sine Lane Change” model is used to obtain the reference trajectories. Gains of the controllers are tuned by using “Particle Swarm Optimization” method. High-fidelity multi-body vehicle dynamics simulations are performed in ADAMS Car and the controller is set up in Simulink environment, resulting in a co-simulation scheme. The simulated results are presented for two scenarios with one high and one low speed cases. The effects of front wheel scrub radius on the success of differential braking are also discussed in detail. This study may shed light on the development of new redundant steering systems for self-driving vehicles.