Abstract: This paper designs a soft robot with a multi-chamber, multi-airbag mimicking soft biological structure, where the airbags of the same chamber are interconnected with each other. The upper and lower chambers are separated by an intermediate layer (thin plate), which is extended and widened to achieve robot movement and balance. By applying pressure to the different chambers of the soft robot, it is possible to produce a variety of bionic movements of the inchworm and caterpillar. Due to the strong nonlinearity and infinite number of degrees of freedom properties of the material, it is impossible to obtain the analytical solution of the bending morphology and pressure of the soft robot directly. Therefore, a method to establish a mathematical model of soft robot deformation based on the classical stacked plate theory is proposed, and a chain composite model of soft robot bending motion is established based on the large-deflection modeling method. This paper proposes a method to generate a multi-mode soft robot motion control based on the Central Pattern Generator (CPG) using a single controller, which achieves the switching of sine wave-like patterns, half-wave-like patterns, and dragging patterns by adjusting frequency, amplitude and period of parameters. Finally, a pneumatic control platform is built for the validation of the theoretical model and different experimental models of the motion of the robot. And comparation of the different motion modes of the soft robot under similar non-load and load conditions.

Key words: Soft robot , · Bionic multi-modal movement , · Laminated plate theory , · CPG control