Robot Diagnosing Method

A robot diagnosing method comprising:

• preparing a robot and a line sensor,
• the robot including
• a robot arm including at least one joint portion,
• a detected portion that is part of a wrist portion of the robot arm, and
• a robot control portion configured to control the robot arm and the wrist portion,
• the line sensor including
• a light emitter configured to emit a band-shaped light ray,
• a light receiver configured to receive the band-shaped light ray emitted from the light emitter, and
• a detecting portion comprising a program configured to, when executed by a processor, detect a position of the detected portion based on a light receiving state of the light receiver, the detected portion being inserted between the light emitter and the light receiver;
• detecting a position of a linearly-extending edge portion of the detected portion by the line sensor while linearly moving the wrist portion based on a command value from the robot control portion such that the wrist portion intersects with the band-shaped light ray;
• and
• diagnosing a property of a waving movement of the wrist portion in a linearly moving state based on the detected position of the linearly-extending edge portion.