Hybrid Vision-Force Control for Automatic Assembly of Miniaturized Gear System

This paper presents the automatic microassembly of miniaturized gear system by hybrid vision-force control with the vision system and the 3-DOF force sensor feedback data. The assembly process consists of three phases, including visual positioning, searching meshing state, and inserting. Visual feedback is used to achieve the coarse positioning and guide the grasping and transporting of microparts during the visual positioning phase. During the searching phase, a fuzzy PID controller is used to control the contact force on z axis and fuzzy logic strategy is developed to search the meshing state by the force feedback on x and y axes. The tolerance compensations movement is used to support the inserting task to avoid the case of blocking and prevent the micro parts from damaging. The assembly experiment of three planetary gears validates the hybrid force control strategy.