Hole position and inclination sensor with 2 dimensional PSD for automatic shaft inserting

摘要

Shaft inserting is frequent and important operation for automatic parts assemble. We have been developing a sensor that detects in real time a position of hole center and its inclination using a 2-dimensional PSD. The sensor can detect the hole position by signals for the center of blight part. When the hole is inclined, a black ellipse image is focused on the PSD, the total current of one pair of PSD electrode differs from that of another pair. Therefore the sensor can detect hole inclination by this current difference. The sensor has about 20μm and 0.3 degree resolution for the position and the inclination sensing respectively.We developed an automatic shaft inserting system applying the position and inclination sensor to a parallel joint robot with four freedom. The output of sensor is sent to PC-98 host computer which evaluates dislocation and inclination values. These values are sent to the robot to correct the shaft position and its inclination.Within 5 sec the robot can insert a shaft into a hole with 50μm of clearance and without chamfering with 2mm dislocation and 3 degree inclination.