Soft pneumatic actuator optimal design based on isogeometric analysis

Abstract

Pneumatic-driven robots are one of the most widely-used soft robots in the industry, such as manipulation tasks in factories and production lines. The structural design for the soft pneumatic actuator is a hotspot in practical applications. This paper proposes a novel optimal design framework based on isogeometric analysis (IGA) for soft pneumatic actuators, which integrates the design, analysis, and optimization in a NURBS-based framework. Firstly, the positions of the control points are defined to construct a NURBS-based geometry model. To solve the design-dependent analysis problem, a pressure-loading method based on IGA is introduced. An optimization model is built to generate the optimal structures based on the selected design variables related to the NURBS curve. After the optimization, the optimized configurations are printed using an extrusion-based additive manufacturing machine with flexible material, and a pressure-loading experiment is conducted. The experiment reveals the deformation pattern of different structures, demonstrates the proposed method’s accuracy and reports the optimized structure performs better than the conventional design. The proposed method provides a high-efficiency optimization way for the structural design of soft pneumatic actuators, advancing in the diverse design space, programming design, and concise optimization model. With isogeometric analysis, the proposed method integrates the deign-analysis-manufacturing system in the NURBS framework, with significant adaptability for a fast-iterating manufacturing system.