Protective relay device of robot arm

Abstract

Abstract PURPOSE:To detect quickly abnormal contact of a robot arm by sampling the load current of a driving motor to perform the averaging processing and outputting an emergency stop signal if the difference between the current result and the preceding result exceeds a set value. CONSTITUTION:A control and driving system of a robot arm 6 provided with a protective relay device inputs the output of an angle detector 5 to a main logic device 1 and controls a motor 3 and a brake 4 through a driving control device 2 by commands from the device 1. This protective relay device 7 consists of an auxiliary logic part 10, a sampling part 9, an output part 11, etc., and a time series table where check point numbers and time element values correspond to each other in relation to the operation cycle of the arm 6 is set in a prescribed area of a RAM12 in the device 7. The load current value of the motor 3 is sampled at every said point by the part 9 to perform the averaging processing, and the difference (deviation value) between the current result and the preceding result is obtained; and if this difference exceeds a preliminarily determined set value, the emergency stop signal is outputted from the output part 11 to stop the arm 6 in the current position.

Inventors

• 👤 Masatsune Kosaka
• 👤 正恒 香坂

Bibliographic Details