This paper proposes an analytical synthesis method for optimal synthesis of planar eight bar mechanism for path generation with variable topology. The eight bar planar mechanism has been considered to be made of three phases where each of the phases is a four bar mechanism of RRRR type. The method of kinematic synthesis involves the use of Cheybeychev's spacing for locating precision points and Freudenstein's equations for determining link lengths. For any given function, link lengths of the

more »

... hanism are determined by assuming the range of input and output angular rotations. Optimized length of rocker link and output angle of the first phase is used as input values for the second phase and same procedure is continued to find the dimensions of the third phase. The combined objective function is established for optimization with transmission angle and link length ratios as design variables. The optimized values of lengths of links of the resulting mechanism satisfy Grashof's condition and have controlled transmission angle. The coupler connected to third phase generates the coupler curve for obtained optimized link lengths. The method developed herein is illustrated with a numerical example.