A survey paper on a factors affecting on selection of mechanical gripper

Abstract

A mechanical gripper is an end effector that uses mechanical fingers actuated by a mechanism to grasp an object. Fingers are the one which makes an actual contact with object. The fingers are either attached to the mechanism or are an integral part of the mechanism. The function of gripper mechanism is to translate some form of power input into grasping action of fingers against the part. The power input supplied from the robot and can be mechanical, pneumatic, hydraulic or electrical. The mechanism must be able to open and close the finger and to exert the sufficient force against the part when closed to hold it securely. The process of handling component parts or workpieces in production is often underrated as technically simple or even trivial. From the production point of view it is obvious that the workpiece itself does not increase in value during the handling process. Since a gripper gives a great contribution to practical success of using an automated and/or robotized solution, a proper design may be of fundamental importance. The design of a gripper must take into account several aspects of the system design together with the peculiarities of a given application or a multi-task purpose. Strong constraints for the gripping system can be considered for lightness, small dimensions, rigidity, multi-task capability, simplicity and lack of maintenance. These design characteristics can be achieved by considering specific end-effectors or grippers. In the last case a two-finger gripper corresponds to the minimum number of fingers and the minimum complexity of a hand.