Multimodal Pneumatic Control System for Soft Robot

In order to satisfy the requirements of output channels, drive modes and pressure detection for the complex motion of soft pneumatic robots, a multimodal pneumatic control system is proposed to solve the problem of pneumatic control and condition detection for multi-chamber soft robot of different shapes. The pneumatic control unit of the system consists of hybrid valve which composed of proportional valve and solenoid valve. In the hybrid valve, the positive proportional valve is connected with the positive air pressure source, and the negative proportional valve is connected with the negative air pressure source, then two solenoid valves are connected in series to switch the air pressure on and off. This enables the controllable output of positive and negative air pressure to control soft robots of different structures. In detection, the solenoid valve is used to achieve pressure detection of the pneumatic control process and the working state detection of the soft robot. Based on the principle of pneumatic control and detection, positive pressure output and detection mode, negative pressure output and detection mode, positive pressure cutoff and chamber pressure detection mode, and negative pressure cutoff and chamber pressure detection mode are realized, and a control of multi-chamber soft robot through channel expansion. The experimental results show that the positive pressure output and detection mode, negative pressure output and detection mode and the negative pressure cutoff and chamber pressure detection mode can adjust the bending attitude of the variable stiffness four-chamber soft robot from 0° to 360° and the maximum stiffness change of 1.47N. Combining positive pressure output and detection mode, negative pressure output and detection mode and positive pressure cutoff and chamber pressure detection mode, as well as 12-channel pressure control and 0−60 kPa chamber pressure detection, the operation control of the six-finger soft gripper and finger damage detection are realized. The multimodal pneumatic control system can adapt to control and detection of various types of soft robots through channel expansion.