A hierarchical adaptive control framework of path tracking and roll stability for intelligent heavy vehicle with MPC

Abstract

Roll stability is a major concern in the path tracking process of intelligent heavy vehicles in emergency steering maneuvers. Due to the coupling of lateral and roll motions of heavy vehicle, steering actions for path tracking may come into conflict with that for roll stability. In this paper, a hierarchical adaptive control framework composed of a supervisor, an upper controller and a lower controller is developed to mediate conflicting objectives of path tracking and roll stability via steering control. In the supervisor, path tracking control mode or cooperative control mode of path tracking and roll stability is determined by the predicted rollover index, and a weight function is introduced to balance the control objectives of path tracking and roll stability in cooperative control mode. Then, in order to achieve multi-objective real-time optimization, model predictive control with varying optimization weights is used in the upper controller to calculate the desired front steer angle. The lower controller which integrates the real electrically assisted hydraulic steering system based on Proportional-Integral-Derivative control is designed to control steering wheel angle. Simulation and hardware-in-loop implementation results in double lane change scenario show that the proposed hierarchical adaptive control framework can enhance roll stability in emergency steering maneuvers while keeping the accuracy of path tracking for intelligent heavy vehicle within an acceptable range.

Roll Stability and Path Tracking Control Strategy Considering Driver in the Loop

“…Obviously, this is a constrained optimization problem, which can be transformed into a quadratic programming problem. The specific implementation process will not be detailed here, more details can be seen in reference [13].…”

“…The proposed integrated control strategy has good path tracking performance and roll stability. Tian et al [13] exploited a hierarchical adaptive control framework to coordinate the contradiction between path tracking and roll stability through steering control.…”

Rollover Prevention Control for Autonomous Electric Road Sweeper

“…In Equation ( 27), v xi,desired is the reference speed that is needed to make the lateral acceleration be a yi,desired for rollover prevention. By eliminating the time derivative of v yi from the two equations of Equation ( 27), the desired longitudinal velocity is obtained as Equation (28). As shown in Equation ( 28), v xi,desired depends on the lateral accelerations, the longitudinal velocity, and the yaw rate, regardless of the various road conditions.…”

“…To prevent the AERS from rolling over, a rollover prevention scheme is proposed in this paper. To date, several rollover prevention controls or schemes have been proposed for passenger or commercial heavy vehicles [24][25][26][27][28][29][30]. In the literature, differential braking, active steering, active suspension, and torque vectoring devices have been adopted as actuators for rollover prevention.…”

“…However, all of the the actuators used in previous research cannot be used for rollover prevention because the AERS only has rear-wheel drive with a single motor. On the other hand, recent research has investigated both the rollover prevention and path tracking controls simultaneously [27][28][29]. For the AERS, the path tracking controller is needed to follow a pre-defined path.…”