Optimal robot speed trajectory by minimization of the actuator motor electromechanical losses (Q1610638)

The authors of this paper consider the control problem of a robotic manipulator whose actuators are separately excited direct-current motor drives. They propose a method for robot speed control with simultaneous minimization of total electromechanical losses as the motor drives follow desired speed profiles of the robotic joints under various loads and random load disturbances. When there is no desired speed profile, the optimal trajectory is determined by minimizing electromechanical losses. Controllable energy losses include armature copper losses, armature iron losses, field copper losses, stroy load losses, brushload losses as well as friction and windage losses. These losses can be expressed as proportional to the squares of the armature and exciting currents, angular velocity, and magnetic field flux. The authors' method is implementable in a straightforward way and could easily be realized with Matlab, for example. Two case studies of optimal robot speed control, with and without use of the minimization of actuator energy losses, are presented and compared.