Path Tracking of Wheeled Mobile Robots Based on Dynamic Prediction Model

Abstract

In the field of path tracking control for wheeled mobile robots, researchers generally believe that the motion of robots meets non-holonomic constraints. However, the robot may sideslip by centrifugal force when it is steering. This kind of slip is usually uncontrollable and dangerous. In order to prevent sideslip and improve the performance of path tracking control, we propose a controller based on tire mechanics. Moreover, the new controller is based on the model predictive control, and this control method has proven to be suitable for path tracking of wheeled mobile robots. The proposed controller was verified by simulation and compared with a model predictive controller based on kinematics (non-holonomic constraints). As for the simulation results, the maximum values of displacement error, heading error, lateral velocity, and slip angle of the dynamic-based model predictive controller are 0.2086 m, 0.1609 rad, 0.1546 m/s, and 0.0576 rad, respectively. Compared with the kinematics-based model predictive controller, the maximum values of the above-mentioned parameters of the dynamic-based controller reduce by 86.55%, 72.25%, 96.30%, and 90.02%, respectively. The above-mentioned results show that the proposed controller can effectively improve the accuracy of path tracking control and avoid sideslip. INDEX TERMS Wheeled mobile robot, path tracking, path following, model predictive control, dynamic model.

Review and Comparison of Path Tracking Based on Model Predictive Control

“…In 1994-1999, Gómez-Ortega et al proposed the NMPC controller and improved the real-time performance of the controller by using artificial neural networks or genetic algorithms [37][38][39][40][41]. After 2000, researchers have proposed more NMPC-based path tracking controllers [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61]. In these studies, Künhe et al [42], Oyelere et al [54], and Li et al [58] have compared NMPC and LMPC.…”

“…All of the controllers are based on the same model. Referring to our previous work [60], the classic kinematics model is:…”

“…Referring to [60], if the control period T is 0.05 s, the constraints of the velocity and heading angle speed in each control period are:…”

“…The radius of the arc is 2.5 m. The displacement error and heading error are the targets of comparison. Their definitions are shown in [60]. Table 1.…”

Path Tracking Control of an Articulated Road Roller With Sideslip Compensation

“…Path tracking is one of the most elemental and important problems in the research of unmanned road roller, whose purpose is to ensure the vehicle can lock into a desired path with a designed control law [4]- [6]. It is important to point out that a road roller is an articulated steering type vehicle, which has two frames (front and rear) articulated by an active revolute joint.…”