Optimum design of spherical parallel manipulators for a prescribed workspace

The optimum design of spherical parallel manipulators (SPM) is studied for a prescribed workspace. A numerical method is developed to find optimal design parameters including link dimensions and architecture parameters for a maximum dexterity. In the method, the objective function is formulated in such a way that the optimal problem is converted to a nonlinear least squares problem, which can be readily solved. Moreover, the problem of design space is addressed. A system of inequalities in terms of link dimensions is derived to describe the design space for feasible SPMs. Examples are included to illustrate the application of the method.