Modeling, Parameter Estimation and Control Design of 4WIS4WID Mobile Robot: Simulation and Experimental Validation

This paper introduces a systematic modeling approach for a mobile robot structure equipped with four-wheel-independent steering and four-wheel-independent driving (4WIS4WID). The mathematical model provided in this study forms the basis for the development of conventional PID controllers for both the steering and driving systems. Additionally, a non-linear kinematic trajectory tracking control law is proposed for accurate trajectory tracking. To ensure the effectiveness of the model, all relevant parameters are estimated, and the driving and steering subsystems are rigorously validated through simulations. These simulations are instrumental in identifying the optimal controller gains required for precise trajectory tracking. Subsequently, the chosen controller gains are implemented on a physical 4WIS4WID mobile robot, and the paper presents the results obtained from both simulation and experimental trials. During the experimental phase, the robot's movements are recorded using the OptiTrack motion capture system, enabling the verification of kinematic parameters, and providing insights for future research endeavors.