Task based kinematic design of a two DOF manipulator with a parallelogram five-bar link mechanism

As the demand for modular manipulators or special purpose manipulators has increased, task based design to design an optimal manipulator for given tasks become more and more important. However, manipulator design problems usually are very complex due to a large number of design parameters, their nonlinear and implicit relationship, and so on. To achieve task based design successfully, it is necessary to develop a methodology that can solve the complexity. This paper addresses how to determine the kinematic parameters of a two degrees of freedom manipulator with a parallelogram five-bar link mechanism from a given task, namely, how to map a given task into the kinematic parameters. With a simplified example of designing a manipulator with a five-bar link mechanism, a methodology for task based design is presented. And it introduces formulations of task specifications and manipulator specifications, and presents a new dexterity measure as an optimality criterion for manipulator design. Also it finds out an optimal design solution for the manipulator by using a genetic algorithm that has robust search performance in complex spaces. (C) 2006 Elsevier Ltd. All rights reserved.