Force control and visual measurement in precision assembly

On account of the assembling demand for the metal framework of frequency stabilizing component for laser gyro, a precision assembly system was designed and developed in this paper. The coaxiality of the metal framework and the grooved mirror is the key index to assembly. Meanwhile, the grooved mirror is fragile and the assembly force has to be monitored and controlled in real time. The installation structure of force sensor is designed and a force control unit is established. The contact force can be detected and feedback to control the movement of the linear stages to complete the displacement in the vertical direction for the operation of pick up and place parts for end effector. To reduce the time of image processing, the machine vision unit is based on high repeatability accuracy of the stage to assist image mosaic, thus the calculation workload for image mosaic is reduced, and the time of image mosaic is about 0.5s.