Journal of Bionic Engineering (2022) 19:657–667  https://doi.org/10.1007/s42235-022-00170-8

Task-oriented Hierarchical Control of Modular Soft Robots with External Vision Guidance 

Xin Sui1  · Tianjiao Zheng1  · Jian Qi1  · Zhiyuan Yang1  · Ning Zhao1  · Jie Zhao1  · Hegao Cai1  · Yanhe Zhu1 

1 State Key Laboratory of Robotics and System, Harbin Institute of Technology (HIT), Harbin 150001, China

Abstract  General, high-precision theoretical modeling method is not well developed in the feld of soft robotics, which holds back motion control and practical application of soft robots. The concept of modularization brings novel structure, novel locomotion patterns as well as novel control method for soft robots. This paper presents the concept of hierarchical control method for modular soft robot system and a H-confguration pneumatic modular soft robot is designed as the control object. The H-confguration modular soft robot is composed of two basic motion units that take worm-like locomotion principle. The locomotion principle of the basic motion unit is analyzed and the actuation sequence is optimized by evolution strategy in VOXCAD simulation software. The diferential drive method is applied to the H-confguration modular soft robot with multi motion modes and vision sensor is used to control the motion mode of the robot. The H-confguration modular soft robot and the basic motion unit are assembled by a cubic soft module made of silicone rubber. Also, connection mechanism is designed to ensure that the soft modules can be assembled in any direction and posture. Experiments are conducted to verify the efect of the hierarchical control method of the modular soft robots. 

Keywords  Soft robot · Modular robot · Locomotion pattern optimization · VOXCAD simulation software · Vision feedback control

Dimensions of the inner cavities of the soft module. a 3D model of the soft module; b the sectional views of the soft module