Fuzzy logic controller design methodology for Cartesian robot control

Abstract

This paper presents an approach for complex task control involving robot-environment interaction. For this purpose, an effective hybrid force/position based-approach for MIMO robot control is proposed. This approach is based on Fuzzy Logic Controller (FLC) design and optimisation methodology operating in two stages: At the first stage, the FLC is trained offline on the basis of data acquired during free motion of the robot, in order to map FLC outputs to real behaviour. A method based on Solis' and Wetts' algorithm is then applied for fuzzy parameter optimisation so that the constraints in terms of interpretability of the predefined rules are respected. Finally, an online learning is implemented into the proposed control structure. The approach has been implemented into an experimental setup, including a 2D Cartesian robot linked to a C5 parallel robot, performing contour following under force constraints. The analysis of the obtained results shows the efficiency of the proposed approach.