Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding

Abstract

An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunovstability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

Nonlinear Control for Autonomous Trajectory Tracking While Considering Collision Avoidance of UAVs Based on Geometric Relations

“…In addition, the proportional (P) controller is used in the end of the robot's journey to guarantee the vehicle reaches a given point and stops there. Furthermore, this study presents a simple, practical, and effective controller in comparison with other advanced methods [54,55] with considerations of the implementation on a real-time embedded system. The full control scheme, introduced in this paper, comprises of a multi-loop architecture, which includes an outer loop and an inner loop.…”

Nonlinear Control for Tracking and Obstacle Avoidance of a Wheeled Mobile Robot With Nonholonomic Constraint

“…Contributions [11] Adaptive control no considering external disturbances at the kinematic level [12] Model-reference control without external disturbances [13] An integrated method and path following no considering external disturbances [14] Binary logic controller and FLC without external disturbances This paper Nonlinear controller with considering external disturbances at the dynamic level according to the actual needs. In this paper, an extended state observer is introduced to estimate the unknown disturbances, which will be compensated in controller (15).…”

“…Moreover, wheeled mobile robots often encounter obstacles when working in complex environment [10]. Based on kinematical equations, some control problems have been studied on tracking and obstacle avoidance, please refer to [11], [12], [13], [14], and so on. Note that trajectory tracking and obstacle avoidance controllers are designed separately in most existing works, which easily lead to the low work efficiency and cause high frequency noise [15].…”

Neural Network-Based Adaptive Motion Control for a Mobile Robot with Unknown Longitudinal Slipping

“…For mobile robots in presence of slip conditions, Gonzalez et al [21] proposed an adaptive control law together with an LMI-Based approach, which guarantee the stability and asymptotical convergence subject to both constraints and varying dynamics. Aimed at the trajectory tracking subject to unknown wheels' slipping, Cui et al [22] addressed the unknown skidding for mobile robots by designing adaptive unscented Kalman filter scheme. Though kinematic modeling with wheel slipping phenomena gives a theoretical possibility of obtaining good performance of the control action, the kinematics model is only taken position and velocity into account, and without model uncertainties, unmodelled or unstructured disturbances, nonlinear friction and other factors.…”