Research on Hierarchical Control of Intelligent Industrial Vehicle Path Tracking Based on Fully Hydraulic Steering Time Delay

An intelligent industrial vehicle path-tracking hierarchical controller considering fully hydraulic steering time delay compensation is designed in this study. The upper decision layer uses variable constraint linear time-varying MPC for path-tracking control. The lower execution layer uses a time delay probability model and variational Bayesian algorithm to estimate the optimal time-delay value and combines with proposed input–output moment equations for the steering system to advance the target steering wheel angle to realize the real-time compensation of steering time-delay disturbance by path tracking. The simulation and test results show that the lateral acceleration, center of mass sideslip angle, tire-slip angle, and tracking error of the intelligent industrial vehicle under different loads and working conditions are improved by 29.8%, 36.2%, 41.5%, and 43.2%, respectively.