Based on the constrained length of the bars

the problem of mechanism synthesis can be transformed into nonlinear equations and then the nonlinear equations are transformed into multi-objective unconstrained optimization problem. All solutions are found with multi ?objective optimization method. Applying the principle of multi ?objective optimization

the new method is proposed to find all solutions of nonlinear equations of mechanism synthesis and the program is compiled with Matlab Optimization Toolbox. The numerical example of linkage synthesis shows that the method is effective.