An Intelligent Robust Tracking Control for a Class of Electrically Driven Mobile Robots

Abstract

This paper addresses the problem of designing robust tracking control for a class of uncertain wheeled mobile robots actuated by brushed direct current motors. This class of electrically-driven mechanical systems consists of the robot kinematics, the robot dynamics, and the wheel actuator dynamics. Via the backstepping technique, an intelligent robust tracking control scheme that integrates a kinematic controller and an adaptive neural network-based (or fuzzy-based) controller is developed such that all of the states and signals of the closed-loop system are bounded and the tracking error can be made as small as possible. Two adaptive approximation systems are constructed to learn the behaviors of unknown mechanical and electrical dynamics. The effects of both the approximation errors and the unmodeled time-varying perturbations in the input and virtual-input weighting matrices are counteracted by suitably tuning the control gains. Consequently, the robust control scheme developed here can be employed to handle a broader class of electrically-driven wheeled mobile robots in the presence of high-degree time-varying uncertainties. Finally, a simulation example is given to demonstrate the effectiveness of the developed control scheme.

A Saturating Extension of an Output Feedback Controller for Internally Damped Euler‐Lagrange Systems

“…The design of tracking controllers for such systems is a difficult task because of the challenging theoretical nature of the problem, according to Brockett's theorem [19,20]. To the best of the authors' knowledge, in spite of the existence of a large number of proposed controllers for nonholonomic WMRs in the literature [21][22][23][24][25][26][27][28][29][30][31][32][33][34], there is no work to theoretically support the idea of designing a bounded output feedback controller to solve the tracking problem of uncertain dynamic nonholonomic WMRs. In this section, the proposed bounded tracking controller is applied successfully to solve this problem for nonholonomic WMRs under actuator constraints and without velocity measurements.…”

“…This makes the EL system track a desired trajectory with less control energy and more acceptable tracking performance in the presence of parametric uncertainties. The proposed controller alleviates fast transient and high frequency components of the control signals in order to provide feasible control signals, considering the limited bandwidth of actuators. An application of the proposed bounded adaptive OFBC to the trajectory tracking of a nonholonomic wheeled mobile robot (WMR) is presented, which is new and attractive from theoretical and practical viewpoints. According to and to the best of the authors' knowledge, there is no result on the bounded adaptive output feedback tracking control of nonholonomic WMRs. Simulation results are provided to illustrate that the controller copes well with actuator constraints when the initial tracking errors are large.…”

“…• An application of the proposed bounded adaptive OFBC to the trajectory tracking of a nonholonomic wheeled mobile robot (WMR) is presented, which is new and attractive from theoretical and practical viewpoints. According to [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] and to the best of the authors' knowledge, there is no result on the bounded adaptive output feedback tracking control of nonholonomic WMRs. Simulation results are provided to illustrate that the controller copes well with actuator constraints when the initial tracking errors are large.…”

Motion Control of a Nonholonomic Mobile Manipulator in Task Space

“…However, these proposed approaches do not consider the dynamics of the mobile robots. This motivates the recent research on integrating the kinematic controller and computed-torque controller for both the mobile robots and the mobile manipulators [2,[7][8][9][10][11][12][13][14][15][16][17][18]. In these works, adaptive control methods and robust control methods have been proposed to control mobile robots subjected to parametric uncertainties and external disturbances [2,[7][8][9].…”

Linear Observer‐Based Active Disturbance Rejection Control of the Omnidirectional Mobile Robot

“…In this article, instead of an intrinsically nonlinear solution to the tracking problem (see for instance, or ) we propose a fundamentally linear, global, approach to the robust output feedback controller design task for nonlinear mechanical systems on which a reference trajectory tracking is demanded on available minimum phase outputs. We propose a robust GPI observer‐based, linear output feedback controller for the trajectory tracking problem in nonlinear mechanical systems.…”