A New Steering and Braking Control Strategy for Tractor Semi-Trailer Truck During a Critical Lane Change Maneuver

In this study, a new integrated control for the steering and braking of semi-trailer trucks for tracking in longitudinal and lateral combined maneuvers is proposed. For this purpose, a nonlinear model of a tractor semi-trailer with 10 degrees of freedom including the longitudinal, lateral and yaw motion of the tractor unit, the articulation angle and the rotational motion of each wheel is used. Then the active steering and braking controller is designed with the purpose of tracking and utilizing the sliding mode method. Also, for the yaw stability of the vehicle, a lateral stability controller is proposed using the sliding control method. Then, by utilizing multi-objective optimization, a new integrated control strategy is presented in order to optimally allocate the longitudinal and lateral forces of the tires. This strategy is designed based on achieving the purposes of tracking and stability by using the capacity of tire forces in the optimum slip range by using variable weight coefficients. In order to implement the integrated controller, the tractor semi-trailer model presented in the TruckSim software is used. The obtained results indicate the excellent performance of the integrated controller strategy designed for tracking by maintaining lateral stability when performing the lane change maneuver with braking. So, by using the proposed controller, the maximum tracking error of the longitudinal and lateral position, the yaw angle of the tractor and the articulation angle are equal to 1.83, 0.56, 4.42 and 9.53%, respectively. This is while in the case of a vehicle without a controller, due to lateral instability, the reference path is not tracked.