Explicit dynamic and MTJ Control of a 3-RRS Parallel Manipulator with mass Compensator

In this paper, a 3-RRS ball and plate parallel manipulator is discussed to obtain the exact kinematics and kinetics of the robot. Numerous types of ball and plate systems, reckoned as multivariable and nonlinear workbenches, are exploited to conduct researches to evaluate advanced control algorithms. Although most of these equipment have been presented as two degrees of freedom (DOF), the presented mechanism possesses 3 DOF. Floating plate of this system has three independent motion, two rotational movements and a translation along the vertical axis. Moreover, three dependent motion, two translational and one rotational, are also available. In order to reduce the required torques produced by servomotors, a mass compensator is designed and exploited. Control of the system has been investigated after deriving kinematics and dynamics equations of motion. In the control section, due to the high complexity of kinematics and dynamics equations, Modified Transpose Jacobian (MTJ) control algorithm which is based on feedback linearization approach is used. The goal is to cause the ball follow the chosen trajectories with properly controlled inputs. Simulation results indicate the ability of the suggested controller to accomplish its task.