Precision assembly method based on coaxial alignment and force control

Abstract

To ensure the assembly performance of precision assembly system, a high-precision assembly system for gear-piece and gear-shaft is developed in this paper, which consists of a computer, two manipulators, a coaxial alignment module(CAM), a selective compliance assembly robot arm (SCARA), an adjusting platform and a force sensor. The CAM is used to calculate the position and angular deviation of gear-piece and gear-shaft. The force sensor is equipped to detect the contact force. In the stage of adjusting alignment, position-based visual servoing (PBVS) is adopted to ensure high precision alignment of parts. In the insertion stage, an impedance control method based on position is proposed to ensure the contact force. Experiments are carried out to demonstrate the validation of the proposed system and methods. Automated assembly of parts with a 5μm gap is achieved.