A force/position controller free of velocity measurement for robot manipulators with bounded torque input

Abstract

Robot manipulators play a crucial role in various industrial and research settings, requiring precise and controlled interactions with their surroundings. Achieving this goal with fewer sensors offers advantages not only in terms of cost and decreased risk of failure but also enhances accuracy and long-termreliability. In this paper,we introduce a nonlinear force/position controller that eliminates the requirement for velocity measurements. This controller provides versatility by facilitating the generation of bounded control actions during robot-environment interactions, ensuring a higher level of safety for both the robot and its environment during the execution of tasks necessitating physical contact between them. The proposed approach is underpinned by a stability analysis in the Lyapunov sense and has been validated through a series of simulation and experimental tests.

Keywords

• force/position control
• lyapunov stability
• robot manipulator
• saturation function