ولی اله غفاری

The overall goal of this study is to find a simple and easy control law to improve the performance of robotic tracking paths and given the popularity and simplicity of proportional-derivative control in industrial applications, the combination of proportional-derivative control and sliding mode control for Robotic systems has focused on a new control rule to deal with tracking tracking problems. Finally, the robustness analysis for a robot with two degrees of freedom with rotation is proved by the Lyapunov method. Research method: In this thesis, a proportional-derivative-sliding-mode control (PD-SMC) scheme is proposed for tracking problem of a two-degree of freedom robot manipulator. In presence of parameter change and system uncertainties, the sliding-mode control law is a simple and also an efficient control policy. In a typical control problem, the proportional-derivative (PD) control law provides a fast response while the stability of the closed loop system is increased. In this thesis, by using of the well-known Lyapunov stability theory, a two degree of freedom robot is considered and then the asymptotic stability of closed loop system would be shown with using of the proposed control law PD-SMC. As a result of this thesis, the asymptotic stability criteria would be checked in term of some simple matrix inequalities. Having satisfaction of such matrix inequalities, the tracking error and its derivative would be converged to zero in the tracking problem of the robot manipulator. The proportional-derivative-sliding-mode control law is comparable with sliding mode control independent of the system model. The simplicity and ease-of-use design of sliding-proportional-derivative method controller is another advantage over sliding-mode control. Numerical simulation results showed that the proportional-derivative-sliding-mode control compared with proportional-derivative control and sliding mode control in the presence of uncertainty, disturbances, and load shift fu