Irregular-Shaped Torsion Spring Design for Gravity Compensation Mechanism Using Chain Algorithm and DIRECT Optimization

A method that uses a modified chained-pseudo-rigid body model (CPRBM) to design an irregular-shaped torsion spring to function as a compact and lightweight gravity compensation mechanism for linkage systems was previously proposed. In this paper, the method that combines the chain algorithm for approximating the deformation of modified CPRBM and the DIRECT optimization algorithm to optimize the spring design is attempted to improve the accuracy and efficiency of the optimization process. By using the chain algorithm, the deformation of the irregular-shaped torsion spring can be approximated quickly and accurately without the need for parallel computing as in the previous method. The DIRECT optimization algorithm is used to optimize the spring design by minimizing the difference between the desired and approximated endpoint positions of the spring more efficiently. A preliminary case study is conducted to verify the effectiveness of the proposed method.