Trajectory generation for a 2-dof over-actuated parallel manipulator with actuator speed and torque limits consideration

This paper discusses the problem of generating trajectory for a 2-dof parallel manipulator with actuator redundancy. We investigate how to transform the speed and torque limits of the actuators to the velocity and acceleration limits in the end-effector space where the desired trajectory is normally specified. How these limits vary over the workspace is also investigated in details for the particular platform. With these limits, the automatic trajectory generation algorithm for traditional x-y table is modified to suit our parallel manipulator with actuator redundancy. Our trajectory generation algorithm can automatically generate symmetric straight line point-to-point trapezoidal trajectory for the parallel manipulator given the start point, the end point, and the desired traveling time. If it is impossible for the parallel manipulator to travel the distance within the desired traveling time under the velocity and acceleration limits, the shortest time trajectory will be generated instead.