OPTIMAL SYNTHESIS OF MECHANISMS FOR PATH GENERATION USING FOURIER DESCRIPTORS AND GLOBAL SEARCH METHODS

Generally, success in synthesis of mechanisms for path generation is l imited to finding a reasonable local optima at best in spite of a very good initial guess. The most widely used Structural Error objective f unction is not effective in leading to practical solutions as it misre presents the nature of the design problem by requiring the shape, size , orientation and position of the coupler curve to be optimized all at once. In this paper, we present an effective objective function based on Fourier descriptors that evaluates only the shape differences betw een two curves. This function is first minimized using a stochastic gl obal search method derived from simulated annealing followed by Powell 's method. The size, orientation and position of the desired curve are addressed in a later stage by determining analogous points on the des ired and candidate curves. In spite of highly non-linear mechanisms de sign space, our method discovers near-global and practical solutions c onsistently without requiring any initial guess.