A simulation study on impedance control of two-degree-of-freedom robotic manipulators

In this research, motion control of a two-degree-of-freedom robotic manipulator with rigid links is studied. Robot control with this approach needs a control system that includes dynamic models of applied torques effecting the positions, speeds, and forces at joints. Hybrid impedance control is proposed in this research to address this need. For hybrid impedance control to be fully understood, position control, force control and impedance control methods are discussed in depth. In the light of the literature review, the mathematical kinematic and dynamic equations of two-degree-of-freedom robotic manipulators are first derived. The manipulator model is converted into a simulation model in computer simulation environment, and the accuracy of the model is proven through open loop tests. The force and position of the end effector of the robotic manipulator is computed with a hybrid impedance control model that can be controlled simultaneously. The designed hybrid impedance controller is integrated into the created robotic manipulator model, and integrated into the closed-loop simulation model along with the PID control system with the purpose of performance assessment. The simulation results are presented in graphs and compared with the desired force control, position control, speed control and joint angle with the force control, actual position control, velocity and joint angle. The simulation is continued until the margin of error reaches the minimum level. Hybrid impedance control is determined to have superior performance compared to other control methods tested. Key Words: 2 DOF Robotic Manipulator, Hybrid Impedance Control