Soichi Arita

Flexible servo control method

A robotic arm is driven by a servomotor which is controlled through position and speed control loops. The position and speed control loops are adaptable in response to a flexible position control. Upon receipt of a flexible control command, a position gain and a proportional gain of the speed control loop are lowered in accordance with a set degree of flexibility. The output of an integrator of the speed control loop is also limited to a set clamp value. As a result, a torque command for controlling the servomotor never achieves an expressly large value even if a position deviation increases. In case an obstacle is placed in the transfer path of the robotic arm, the arm can be moved by human power to avoid the obstacle.