Fuzzy Nonprehensile Manipulation Control of a Two-Rigid-Link Object by Two Cooperative Arms

Motivated by the application of robots in holding and/or transferring a patient, this paper introduces the nonprehensile manipulation control algorithm for lifting up (or lowering down) a two-rigid link object with a passive joint applying two cooperative arms in a two-dimensional space. Fuzzy technique is applied for manipulation control, with high friction at contact, as it is very difficult to be done by conventional model based methods. A fuzzy controller is designed for every variable of the four dimensional position vector specifying the joint’s position and links’ orientations. A rule of a fuzzy controller would be like a human would do: while the friction at contact is high, “IF the reference position is far THEN move the hands quickly forward”. An enhanced dynamic model of the system with high friction at contact for simulation purposes is presented. Simulation results for the manipulation control with the proposed fuzzy controllers are presented to verify the validity of the proposed control algorithm in the achievement of the manipulation motion.