APPROXIMATE SYNTHESIS OF PLANE 4-BAR MECHANISM FOR RIGID BODY GUIDANCE

An analytical method is presented for the synthesis of a plane four-bar mechanism to guide a rigid body through five precision positions. The numerical procedure for determining the values of ten design parameters of a rigid body guidance mechanism is established in a concise form that consists in solving three systems of five linear equations and a quartic equation. This method is extended to the synthesis of such a mechanism that the higher order differential coefficients of three position variables of the segment on the coupler link at precision positions may coincide with the specified values. Moreover, combining some calculations on the basis of the Roberts-Chebyshev theorem with the numerical procedure, this analytical method may be used as a general precision derivative approximation for designing a path generatinag mechanism or a function generator.