Abstract
A new approach to the synthesis of planar linkage mechanisms is proposed. Design methods for two exact positions and an arbitrary number of approximate positions are presented. Approximate velocities may also be specified at the exact positions. The use of approximate position and velocity specifications allows the designer to more realistically represent design objectives. The same design procedure is used regardless of the number of approximate positions or velocities specified.
A precision position synthesis approach is used to generate a complete three-dimensional solution space of dyads satisfying all exact and approximate constraints. The solution space may be reduced to a two-dimensional ground-pivot map where the best solution at each ground pivot is determined through one-dimensional optimization. This optimization step occurs within the solution space. Therefore, the position and velocity objectives need not be included in the objective function.
Dyad synthesis methods for two exact and n approximate positions are applied to four-bar linkage design for motion, path and function generation. Approximate velocity specifications are added to the four-bar motion generator. Solution rectification is developed for the mixed exact-approximate position synthesis of a four-bar linkage. Triad synthesis methods for mixed exact and approximate positions are also presented. Combinations of dyad and triad synthesis techniques may be used to design multi-loop linkages.