Manipulator design for optimal dynamic motions along specified paths

Design methods of robotic manipulators for optimal motions along specified paths are presented. The design problem is formulated as a parameter optimization, using the optimal motion time along the given path as the cost function, and the link lengths or the actuator sizes as the design parameters. Based on geometric insights into the shapes of time optimal paths, an approximate method is also presented that curve fits the acceleration lines to the specified path, avoiding the computationally expensive time optimization problem. The approximate method yields efficiently near optimal designs in a fraction of the computation time required for the exact solutions. Design examples of a five-bar mechanism are presented, showing a close correlation between the exact and approximate solutions.