Fuzzy-PI force control for industrial robotics

Abstract

Increasingly, robot programs are generated off-line, for example, through a virtual model of a robotic cell. However, when the virtual model does not reproduce exactly the real scenario or the calibration process is not performed correctly it is difficult to generate reliable robot programs. In order to circumvent this problem, it was introduced sensory feedback (force and torque sensing) in a robotic framework. By controlling the robot end-effector pose and specifying its relationship to the interaction/contact forces, robot programmers can ensure that the robot maneuvers correctly, damping possible impacts and also increasing the tolerance to positioning errors from the off-line programming process. In this paper Fuzzy-PI and PI reasoning was proposed as a force control technique. The effectiveness of the proposed approach was evaluated in a serie of 20 experiments that demonstrated that Fuzzy-PI controllers are more suitable to deal with this type of situations. © 2010 Springer-Verlag.