A Synthesis of a Six Bar Mechanism with Nonlinear Stiffness for Prismatic Compliant Joint

A prismatic compliant joint (PCJ) composed of a linear spring and a six-bar mechanism is proposed in this paper. The operating principle of the PCJ is discussed and its mathematical model is established. The main contribution of the proposed PCJ lies in its nonlinear stiffness capability achieved thanks to only passive mechanical elements. An optimal synthesis of the six-bar mechanism with nonlinear stiffness is presented. A genetic algorithm approach (GA) is used in order to explore and identify optimal design solutions. A CAD model and a first prototype of the PCJ are presented.