| 摘要 |
PROBLEM TO BE SOLVED: To detect shifting of a movable part and to prevent accidents such as damaging of carried articles during a carrying process by providing a positional shift detector for detecting a positional shift between the movable part and a fixed part. SOLUTION: When an excessive load is applied on a receiving base 8 or the like, sliding occurs in the articulated part of an arm and a difference occurs between an arm position recognized by the controller of a device and an actual position by an encoder attached to a motor, since no luminous fluxes are made incident from a receiving light optical fiber 20 on a projected light optical fiber 19 in a homing position recognized by the controller, no detecting signals are outputted from a light receiving element and the controller detects the occurrence of a positional shift. For correcting a shift amount, entering of luminous fluxes from the projected light optical fiber 19 to the receiving light optical fiber 20 is monitored and, by outputting a reset signal or the like in a position for entering of the luminous fluxes to the receiving light optical fiber 20, a count signal or the like from the encoder is reset. |
