Model of Variable Volume Tank used for Portable Air Supply Sysetm

Abstract

Wearable robots are desired to be lightweight from the viewpoint of safety and load reduction, so compressed air source is required to have high portability in order to install it in a wearable robot. The portable air supply system for wearable robot had been developed in previous works. The proposed system constructed with a compressor and a variable volume tank, which has been developed in our previous works, and has a mechanism of recompressing exhausted air. The developed tank can accumulate pneumatic energy converted into elastic energy. In addition, this tank can mitigate pressure change even when inflow or outflow of compressed air. The previous system can decrease energy consumption by the pressure mitigation characteristics of the variable volume tank. However, this tank had been made by trial and error to realize ideal characteristic. In this study, the model of variable volume tank is proposed to design the tank which has ideal deformation and energy characteristics. Moony-Rivlin function is introduced in the proposed model to calculate the deformation of rubber material. The energy characteristic is simulated based on this calculated deformation characteristic. In this paper, the accuracy of the proposed model is verified by comparing it with the characteristics of the variable volume tank manufactured based on the model.