Observer-Based Adaptive Tracking Control of Wheeled Mobile Robots With Unknown Slipping Parameters

Based on wheeled mobile robots (WMRs) with unknown longitudinal slipping parameters, an adaptive control strategy for a tracked mobile robot is presented, in which the longitudinal slipping of the left and right wheels are described by two unknown parameters. The kinematic model of mobile robot with wheels' slipping is derived from the motion model of mobile robot without wheels' slipping. Employing the Lyapunov direct method, an adaptive nonlinear feedback control law that compensates for the longitudinal slipping is proposed to achieve an objective of tracking a given trajectory. The orientation angle observer is designed to estimate the immeasurable orientation angle of the robot by employing the coordinate information. Asymptotic stability of the closed-loop system is ensured by choosing an appropriate Lyapunov function. Numerical and experimental results show the effectiveness of the proposed control approach.