Position/Force control for robot manipulators without force and velocity measurements ☆

In the most position/force control schemes for robot manipulators, it is often assumed that a complete description of the system, including an accurate model with velocity, the position of links and reaction force between the end-effector of robot manipulators with the environment are measured by sensors. In this paper, a velocity/force observer is designed by using the Generalized Proportional Integral (GPI) technique to estimate the angular velocity of joints and contact force instead of using velocity/force sensors in constrained movements of robot manipulators. More ever, only position measurements are required. An adaptive force/position control scheme is proposed by a combination of the designed observer with an adaptive control law for position and force tracking of robot manipulators with the constraints of the movement in the environment and uncertain parameters in the dynamic model. The simulation results are presented to validate the proposed method