Simultaneous Multi-channel Positive and Negative Pneumatic Boosting System for Operating Pneumatic Soft Actuators

In this study, a novel system that can produce both positive and negative pressure in multiple channels using a single pneumatic pump is proposed. The pressure-tracking ability of the system is enhanced by incorporating boosters. The multi-channel pressure generation is achieved through the use of proportional valves and regulators controlled by PID, with a disturbance observer added to reduce the impact of coupled dynamics from simultaneous positive and negative generation using a single pneumatic pump. Positive pressure is boosted by a compressed air cartridge, and negative pressure is boosted by ejectors. The system was tested using two positive pressure actuators and two negative pressure actuators that followed target step inputs simultaneously. The results show that the system can effectively follow multiple channel target pressures and increase the following speed through the use of boosters. The rising time for two positive pressure channels was reduced from 1.5470 seconds and 1.2730 seconds to 0.3140 seconds and 0.4970 seconds with the boosters. Similarly, the rising time for two negative pressure channels was reduced from 2.8751 seconds and 2.2940 seconds to 0.1150 seconds and 0.1300 seconds with the boosters.