Robust Controller Design for Trajectory Tracking of Robot Manipulators in the Presence of Uncertain Dynamical Models

The purpose of this activity is to design and simulate a robust controller for a robot manipulator tracking a trajectory in case of uncertainties in the dynamical model. In this study the main goal is to introduce a way to overcome the usual assumptions made in the design of the robustness which depends on a previous knowledge of some parameters. Matlab has been adopted as a computing environment for the development of the design. The analysis of the obtained results has been carried out through Simulink toolbox. After the derivation of the model describing the dynamics of the robot under analysis, a simple feedback control system has been implemented to control the position of the manipulator. To enhance the robustness of the system stability, the previous structure has been subsequently improved by introducing a term that represents the robust contribution that counteracts the indeterminacy in computing the nonlinear terms that depend on the manipulator state. To overcome the assumptions made in the design of robustness term that need previous knowledge of some parameters, a technique which depends on the evaluation of the Lyapunov function is used to determine this term.