Robust Parameter Design and Analysis of a Leaf Compliant Joint for Micropositioning Systems

A compliant joint is used to store and transfer the elastic energy for flexure-based mechanisms. This paper proposes a robust parameter design and analysis for a leaf compliant joint. The joint can achieve a large working travel in the micrometer range. The sensitivity of length l, width w, thickness t and filleted radius r of the joint on the responses are analyzed via finite element method. The parasitic error, dynamics and stiffness are then described. In addition, the stiffness of the joint is reinforced via embedded the silicone rubber into the cavity. Subsequently, the robust optimization of parameters is conducted via the Taguchi method. Analysis of variance is used to determine the effect degree of each parameter. To solve the continuous optimization problem, the second optimization is carried out by integrating of the response surface methodology and differential evolution algorithm. Compared with the genetic algorithm, the proposed optimization method has a faster convergence. The experimental validation is performed to measure the displacement of the joint. The results indicated that the joint can achieve the displacement up to 140.93 $$\upmu \hbox {m}$$μm. The proposed hybrid optimization algorithm can improve the performance of the leaf compliant joint. The proposed joint can be used for the micro-indentation device for testing the micromechanical properties of micro-sized materials. It can be also developed for biomedical rehabilitation devices to assist disable people.