Patent ID: 7248943
Filing Date: 2007-07-24
Classification: B25J,G05B

Abstract:
1. A method of judging whether a communication state between a main control unit and a sub control unit through a signal line is normal or abnormal in a control system, which includes: the main control unit for controlling drive of an entire set of linkages connected by a plurality of joints; a plurality of the sub control units communicatively connected to the main control unit through the signal lines that pass through one joint portion of the set of linkages; a drive system power source; and an actuator for driving the set of linkages about each of the joints by being supplied with power from the drive system power source through a drive system power line that passes through the one joint portion of the set of linkages, wherein the sub control units include a first sub control unit that is provided in a midstream of the drive system power line and controls actuation of the actuator by controlling power supply from the drive system power source to the actuator based on communication with the main control unit through the signal line, the method comprising the steps of: a power supply step of supplying power from the drive system power source to the first sub control unit in a case where the signal line and the power line are concentrated at each of the joint portions of the set of linkages, while the power supply from the drive system power source to the actuator is stopped; a test communication step of performing test communication between the main control unit and the sub control units while power is supplied from the drive system power source to the first sub control unit by performing the power supply step; and a judgment step of judging whether the communication state between the main control unit and each of the sub control units is normal or abnormal based on a result of the test communication between the main control unit and each of the sub control units which is performed in the test communication step.