Hybrid fuzzy control of an eye-to-hand robotic manipulator for autonomous assembly tasks

This paper presents a hybrid fuzzy control approach for a robotic manipulator to perform assembly tasks autonomously. Hybrid force and pose control typically employs an expensive high dimensional force sensor in addition to vision sensors. In contrast to traditional approaches, a low-cost single-axis force sensor together with two CCD cameras and a laser projector can be applied to carry out hybrid force and pose control of a robotic manipulator on 3-D unknown surfaces. Specifically, design of hybrid fuzzy control approaches has been applied to eye-to-hand binocular visual servoing configurations. After visually determining the direction normal to the 3-D surface at the center of the target position by reconstructing the laser cross projected by the laser projector, a robotic manipulator equipped with a low-cost single-axis force sensor is able to perform hybrid force and pose control for drilling, bolting, and screw locking tasks. The proposed approaches have been successfully validated on 3-D unknown surfaces by performing experiments with an industrial 6-DOF robotic manipulator.