The Integrated Disturbance Estimation and Non-Singular Terminal Sliding Mode Longitudinal Motion Controller for...

In the current literature, few motion control studies have considered the disturbances caused by road profile, model uncertainty, and actuator delay in regard to low-speed autonomous vehicles. In addition, motion controller designs usually rely on motor/brake torque control, which is not always available. This study outlines an integrated disturbance estimation and non-singular terminal sliding mode controller (NS-TSMC) to overcome disturbances in low-speed scenarios through traction/brake pedal position control. First, a longitudinal dynamic model that considers a detailed brake-by-wire hydraulic braking system model and a motor actuator model is proposed. Road disturbances, model uncertainty, and actuator delays are also considered in vehicle modelling. This vehicle model was verified through experimental data from a low-speed autonomous sightseeing vehicle. Then, based on the proposed vehicle model, the disturbance and uncertain parameter estimator was designed and integrated with NS-TSMC to achieve longitudinal motion control through throttle/brake pedal control. Experimental results from the experimental sightseeing vehicle and simulation results demonstrated the improvement of the longitudinal motion tracking performance and motion comfort compared with a benchmark proportional-integral-derivative (PID) longitudinal motion controller.