Two-Flexible-Fingers Gripper Force Feedback Control System for Its Application as End Effector on a 6-DOF Manipulator

Abstract

Flexible manipulators have many advantages over rigid robots when used in grasping tasks, owing to the characteristic flexibility of the materials used in their construction, which allow them to absorb energy during impact and make them controllable in order to limit the force applied during contact. In this paper, a two-flexible-finger gripper with a simple sensory feedback system is proposed. A generalized proportional-integral controller is implemented to acquire high control accuracy, while eliminating the need for derivatives of system output. The performance of this force feedback control system is investigated when mounted on a 6-degree-of-freedom (6-DOF) manipulator and grasping different objects. The experimental results indicate that the system proposed is able to manipulate different types of objects (both rigid and flexible) in an industrial environment by perfectly controlling the applied contact torque.