Motion Planning and Compliance Control for Intelligent Contact Assembly Based on Force Screw Decomposition
摘要
Contact assembly operations have long been a subject of intense research interest in the field of robotics. The prevailing solutions currently in use include series robotic arms, as well as non-standard automation equipment. Nevertheless, in certain contact assembly scenarios where high accuracy is required, these devices are unable to achieve the desired assembly task through pure positional motion. To address this situation, this paper investigates a new model of position-force responsive joint assembly operation using a series robotic arm in combination with a parallel robot to realize position actuators and force compensators, respectively. The wide range of sub-millimeter coarse positioning of the series robotic arm enables the assembly positions to be accurately identified through a finite number of collisions in the assembly process with the parallel mechanism. This allows the response and compliance to the contact force in the assembly to be realized. This paper discusses the use of cylindrical and cuboid parts in assembly operations and proposes a control method combining admittance compliance and dynamic feedforward based on the synthesis and decomposition of force screw. This method effectively reduces the target dimension of the contact force controller and enables fixed-parameter and fixed-mode control of forces and moments in arbitrary states. The related planning and control algorithms in this paper are validated through simulation. Moreover, the proposed scheme is effectively verified by utilizing the mouse receiver assembly, cylindrical part assembly, and memory module assembly as experimental targets, resulting in satisfactory assembly outcomes. The related work presented in this paper provides a foundation for new modes, methods, and applications of intelligent assembly.