Fanuc Corporation

Tokyo Institute of Technology

Masumi Ohno

Hikaru Yamashiro

Kenichiro Abe

Yunfeng Wu

Yukio Takeda

Soichi Arita

Hiroshi Nakagawa

Daisuke Matsuura

Hideo Matsui

Yusuke Sugahara

A device and method for judging the presence or absence of an abnormal clearance between paring elements of a passive joint of a robot. The device has sections configured to: calculate a score for each motion path, wherein the score is increased when the paring elements of an objective pair collide with each other and is decreased when the paring elements of the other pair collide with each other; generate a robot motion for moving the robot along the motion path having the score not lower than a predetermined threshold; measure a drive torque or a current value of a motor when the robot is moved according to the generated robot motion; calculate an index value based on a magnitude of variation of the measured drive torque or current value; and judge as to whether the abnormal clearance exists in the objective pair, based on the index value.

Device and method for detecting abnormality of joint of robot

A device and method for easily detecting an abnormality of a joint part of a delta-type parallel link robot having a link ball structure, by estimating a friction torque of a ball joint of the robot. A controller of the robot has: a control section configured to control the motion of the robot; a torque measurement section configured to measure or calculate, during the robot is operated, an amount of change in a drive torque, based on a current value of the motor, before and after the robot represents a specified posture where a sign of a relative angular velocity between a ball and a housing of the ball joint is changed; and a judgment section configured to judge that, when the measured amount of change in the drive torque exceeds a predetermined threshold, a friction state of the ball joint corresponding to the motor is abnormal.

Device and method for detecting abnormality of joint of parallel link robot

Growing community of inventors

Tokyo, Japan

Masumi Ohno