Patent Number: 6,298,283

Title: Industrial robot

Abstract: An industrial robot capable of preventing re-collision after colliding with an obstacle. Disturbing torque exerted on each servomotor for a robot axis is estimated by its associated disturbance estimating observer. When a hand attached to an end of a robot arm collides with an obstacle, an estimated value of disturbance given by a disturbance estimating observer exceeds a predetermined threshold, and the collision is detected. Then, each motor for driving a robot arm is drivingly controlled with a velocity command turned to "0". Each motor for driving the robot hand is driven with torque having a predetermined magnitude (maximum magnitude) and the same sign as that of an estimated value of disturbing torque exerted on it, for a predetermined time, and then it is brought to an emergency stop. Thus, after colliding with an obstacle, the robot hand is driven in a direction such that it recedes from the obstacle. Therefore, the robot hand is prevented from colliding with the obstacle again, and parts of the robot, the hand and the obstacle are prevented from being damaged by collision.

Inventors: Kato; Tetsuaki (Hadano, JP), Tsuchida; Yukinobu (Minamitsuru-gun, JP)

Assignee: Fanuc Ltd.

International Classification: B25J 9/16 (20060101); G05B 019/04 (); G05B 019/18 ()

Expiration Date: 10/02/2018