sitions, for example. The calculated points are found by solving a set of equations that define the behavior of the linkage geometry, using assumed initial values for the linkage parameters. A set of inequality constraints that limit the range of variation of parameters such as link length ratios, Grashof condition, or transmission angle may also be includ ed in the calculation. New values of linkage parameters are generated with each itera- tion step according to the particular optimization scheme used. The closest achievable fit between the calculated solution points and the desired points is sought, defined as minimization of the chosen objective function None of the desired points will be exact- ly matched by these methods, but for most engineering tasks this is an acceptable result.