Abstract:

To enhance the emergency collision avoidance performance of commercial vehicles， the way of steering / braking joint collision avoidance is adopted. In view of that tractor semi-trailer combination is prone to instability in emergency steering， a nonlinear model predictive controller with consideration of rollover and yaw instability prevention is designed and validated by simulations under different load and speed conditions in emergency collision avoidance scene. Accounting for the inadequate real time performance of the controller， with which as the datum of tracking performance a linear time-varying model predictive control algorithm is designed for improving its real time performance in a condition of meeting the requirements on the tracking accuracy of collision avoidance trajectory. Finally， a small scaled test vehicle of tractor semi-trailer combination is produced to carry out trajectory tracking verification in emergency collision avoidance condition. The results show that the control algorithm designed can accurately follow the target trajectory， meeting the requirements of practical application.

Key words: tractor semi-trailer combination, emergency collision avoidance, trajectory tracking, model predictive control, real vehicle verification