Comparison of linear and non-linear controllers for active steering of vehicles in evasive manoeuvres

Abstract

This paper presents different control approaches to perform an evasive collision avoidance manoeuvre using active steering. Linear and non-linear controllers to control the combined lateral and longitudinal motion of the vehicle using predefined trajectories are compared. A proportional–derivative controller, a linear quadratic regulator (LQR), and two different sliding-mode controllers (SMC) were developed. The second SMC model includes an additional velocity error term, which augments the model with a steering actuator term. The controllers were implemented on a bicycle model and a 17 degrees-of-freedom (DOF) vehicle model. The results showed that all controllers perform similarly in controlling the trajectory of the bicycle model. However, in implementation on the non-linear full vehicle dynamics model, the LQR and SMCs provided similar position tracking, but the two SMCs performed better in minimizing the yaw (directional) error at the end of the trajectory. However, at a higher velocity, SMC2 resulted in a more stable manoeuvre than SMC1.