Precision Peg-in-Hole Assembly Strategy Using Force-Guided Robot

Abstract

Position error is inevitable in robotic precision assembly task, so force sensor is needed to get information of the environment and guide the motion of robot. In order to describe assembly task clearly, we divided it in three phases: 1.Move to a certain position; 2.Move the shaft to the exactly top of the hole; 3. Put the shaft down in the hole. Phase1 is easy because the position of the hole and shaft is already known. In Phase2, we divide the contact area in sixteen regions, and detect the regions using KD-tree method. After detecting the regions, a coordinate search path is followed in finding the position of the hole. In phase3, we fine adjust the shaft on the X-Y plane according to the value of x F and y F , and put the shaft down in the hole. In order to validate the strategy, experiments are conducted on a Cartesian coordinate robot. Multiple position error is considered and the strategy perform well.