Robomechs: a new class of linkage arms for multi-task applications

Abstract

A typical robot arm of serial or parallel chain structure has one end effector and the dimension of its links are not synthesized for a specific task. Meanwhile, a path or motion generator mechanism is designed to perform a specific task utilizing one point of its coupler link. In the present paper, a new class of linkage arms, called Robomechs, which are neither robots nor mechanisms is introduced. A robomech is characterized as being task specific in the sense that its links are sized for a desired task, has a parallel architecture, and has more than one end effector for simultaneous multi-functions task performance. Because the number of its actuated joints is less than the number of task variables, a robomech is an overconstrained linkage whose links have to be synthesized, after satisfying some constraints, for the desired task. Hence, a robomech can only traverse trajectories through a number of precision positions and is not suitable for continuous path operations. This paper presents Robomech-I. It has two endpoints, two actuated joints, and its structure is based on a five-bar linkage. The features of the robomech are introduced, the essential constraints to be imposed in determining its link demensions are established, and an application example is given.