The optimal design of robot drive system-gear ratios and actuator impedances

Robots are employed in flexible manufacturing systems. More robots of better performance are needed for a variety of industrial applications. This paper focuses on designing the manipulator-drive assembly having the desirable properties of quick dynamic response and isotroplc velocity convergence to improve the robot performances and partially satisfy those needs. The design variables are identified to be functions of gear ratios and actuator impedances. An appropriate performance function is proposed and proven to be a convex function of the design variables. A design procedure that optimally matches gear ratios and actuator impedances to achieve quick and isotropic velocity convergence is developed using the algorithm adopted from Nonlinear Programming to search for the global optimal design. Efforts are also attempted to locate good starting points for the search algorithm. The drive system of an already existing manipulator i.e., CMU DD Arm, is redesigned to illustrate the design procedure.