Chamber layout design optimization of soft pneumatic robots

This paper presents a study on improving the mechanical performance of soft pneumatic robots through parameterized layout and shape optimization of air chambers. Most soft robots are designed mainly by using biomimetics or engineering intuition. To fully explore the potential of the soft robots, however, it is highly desirable to develop a rational and systematic method to optimize the structural layout. In particular, structural stiffness of soft pneumatic robots is a key issue to be considered in practical design. This study first shows that the structural layout has a significant impact on the structural stiffness of the soft robot. In the optimization model, the design parameters explicitly defining the layout and shapes of the air chambers are to be optimized. In order to attain adequate structural stiffness so as to enhance the gripping force while improving the delivered motion, the output work is considered as the objective function to be maximized. This optimizaiton model enables a gradient-based mathematical programming algorithm to be used. It is shown through finite element analysis and physical experiments that the optimized layout and shape of the air chambers significantly improve the output work of the soft pneumatic gripper. The method is also adapted to be used in the structural design of a crawling soft robot.