Discontinuous force-based robot adaptive switching update rate impedance control

Abstract

For the robot force control system, affected by the uncertainty of system modeling, unknown environmental parameters, nonlinear time lag and unknown external disturbances, classic force control schemes such as: hybrid force/position control, impedance control are suppressing transient forces the overshoot and steady-state force tracking phases cannot achieve good results. Therefore, this paper proposes an adaptive switching update rate impedance control scheme (SAHI) based on the above control algorithm. The algorithm dynamically changes the damping parameters in the impedance model and adjusts the adaptive update rate appropriately to compensate for environmental parameter errors. The force tracking error caused by the robot system model error not only solves the transient force overshoot problem in the case of discontinuous force tracking, but also guarantees the steady-state force tracking accuracy. And based on the Routh criterion, the stability analysis of the system ensures that all parameters and states of the entire closed-loop system are consistent and ultimately bounded. The simulation part compares the dynamic performance of different stages of hybrid impedance control (HI), adaptive hybrid impedance control (AHI), and adaptive switching update rate impedance control (SAHI), which verifies the effectiveness of the research scheme.