A Robust Region Control Approach for Simultaneous Trajectory Tracking and Compliant Physical Human-Robot Interaction

For the safe and smooth robot-assisted healthcare task execution, real-time motion tracking controls and compliant physical human-robot interactions are concurrently important control objectives. In this work, the uncertainty and disturbance estimator (UDE)-based robust region tracking controller for a robot manipulator is developed. The regional feedback error is derived from the potential function to drive the robot manipulator end-effector converging into the target region, where the safe and compliant physical human-robot interaction can be achieved. Utilizing the back-stepping control approach, the regional feedback error is seamlessly integrated into the UDE-based control framework, where the UDE is employed to estimate and compensate model uncertainties such that only the minimum model information is needed for implementation. The Lyapunov method is used to analyze the stability of the closed-loop control system. Extensive experimental studies including trajectory tracking, human-robot interaction and benchmark comparison are carried out for controller effectiveness validation.

Automated summary

To achieve safe and smooth robot-assisted healthcare task execution, real-time motion tracking controls and compliant physical human-robot interactions are crucial control objectives. This work develops a robust region tracking controller based on the uncertainty and disturbance estimator (UDE) for a robot manipulator. By using the potential function, the regional feedback error is derived to drive the robot manipulator end-effector to converge into the target region, enabling safe and compliant physical human-robot interaction. The UDE-based control framework integrates the regional feedback error seamlessly with the back-stepping control approach, utilizing the UDE to estimate and compensate for model uncertainties while requiring minimum model information for implementation. The stability of the closed-loop control system is analyzed using the Lyapunov method. Extensive experimental studies, including trajectory tracking, human-robot interaction, and benchmark comparison, are conducted to validate the effectiveness of the controller.