Enhanced Admittance Control for Time-Varying Force Tracking of Robots in Unknown Environment

In this paper, we introduce admittance control as an approach to control the physical interaction between robot and environment, and propose an enhanced admittance controller (EAC) framework with a well-designed control scheme that improves the system response while possessing the ability to suppress transient force overshoot and maintain steady-state force tracking. Within this framework, we analyze the pre-fuzzy PID, environmental parameter estimation, computed torque control, and propose a time-varying force control theory analysis based on the traditional target admittance model, and introduce an adaptive algorithm to compensate the environmental uncertainty, and verify the stability of the system based on the Routh criterion and Lyapunov equation. Finally, simulations are performed to verify the proposed control scheme in terms of system response, transient and steady-state force overshoot, and steady-state force tracking. Finally, simulations are performed to verify the effectiveness of the proposed control scheme in terms of system response, transient and steady-state force control performance.