Adaptive Admittance Control for Collaborative Assembly Using Dual Parallel-Serial Robots

The admittance control is currently an effective method for enabling robots to perceive external environments, adapt to complex assembly conditions, and furtherly achieve satisfactory compliant assembly. Aiming at the limitations of serial robots with insufficient load capacities, this paper puts forward an asymmetrical multi-robot assembly solution based on dual parallel-serial robots. This system integrates the complementary advantages of different robots, effectively resolving the conflict between precision and flexibility. Focusing on the ability to assembly with compliance of this parallel-serial robots system, a fuzzy adaptive admittance control strategy for typical assembly scenarios is proposed. This strategy incorporates an adaptive update function utilizing fuzzy inference and an improved hyperbolic tangent function for adjusting the damping parameters. Eventually, the effectiveness of this method is verified through peg-hole assembly experiment on a prototype.