ROBOT MALFUNCTION INDICATION METHOD

In sensor-less collision detection of a robot, a conventional method for displaying abnormality of the robot makes an abnormality display of “collision detected” when a collision is erroneously detected, and does not clarify the situations under which the collision has been erroneously detected. In a method for displaying abnormality of a robot, when a collision of the robot is detected and the collision detection is displayed, at least one abnormality display is selected from a plurality of abnormality detection items different from collision detection. This can offer information useful for the user to understand the situations at occurrence of the erroneous collision detection.