A robust tracking controller for electrically driven robot manipulators: Stability analysis and experiment

Abstract

Abstract:In this paper, a robust controller for electrically driven robotic systems is developed. The controller is designed in a backstepping manner. The main features of the controller are: 1) Control strategy is developed at the voltage level and can deal with both mechanical and electrical uncertainties. 2) The proposed control law removes the restriction of previous robust methods on the upper bound of system uncertainties. 3) It also benefits from global asymptotic stability in the Lyapunov sense. It is worth to mention that the proposed controller can be utilized for constrained and nonconstrained robotic systems. The effectiveness of the proposed controller is verified by simulations for a two link robot manipulator and a four-bar linkage. In addition to simulation results, experimental results on a two link serial manipulator are included to demonstrate the performance of the proposed controller in tracking a given trajectory.

Design of a robust tracking controller for a nonholonomic mobile robot based on sliding mode with adaptive gain

“…In view of equation (7), it is clear that for nonholonomic robots, the constraints of motion are introduced using the multiplier constraint l. Those parameters are not constant and depend on the generalized coordinates and the time factor. Hence, the use of the transformation's coordinate is an interesting solution to reduce these multipliers.…”

“…Substituting equations ( 12) and ( 14) into the dynamic motion of the robot expressed by equation (7) leads to…”

“…1,2 Over the last decade, a lot of research effort has been put into the design of sophisticated control strategies for strongly nonlinear systems, such as nonholonomic mobile robots. [3][4][5][6][7][8] Although this class of robotic systems presents great advantages in terms of high energy efficiency, fast and precise response flexibility, and advanced control dynamics, it is very sensitive to disturbances and uncertainties. This criteria has encouraged the researchers to focus deeply on studying the stability and trajectory tracking of the considered system.…”

“…This criteria has encouraged the researchers to focus deeply on studying the stability and trajectory tracking of the considered system. [7][8][9][10][11][12][13] In this framework, Shojaei and Sharhi 14 introduced an adaptive robust controller for nonholonomic robotic systems, where parametric and nonparametric uncertainties were taken into account. Parametric uncertainties were compensated via an adaptive controller and the nonparametric uncertainties were suppressed by a sliding mode controller.…”