*2.2.1. Specification analysis*

The AIRS mechanism is installed on top of the AUV and dives down into the ocean. One should note that the hydrostatic pressure exerted by a liquid increases with increase in ocean depth, which influences the specification of the cylinder. Not only that, the full displacement and weight of the AUV also affect the size of the airbag and cylinder. These interrelated factors cause the different performance of the airbag inflation time and rescue time. To analyze the inflator specification more accurately and conveniently, we have engineered the specification calculator for the inflator to ensure that the airbag can be inflated and can bring the AUV to surface successfully. From the required buoyancy and the depth of the location, the calculator analyzes the required gas cylinders and airbag volume.

From the result of the calculation illustrated in **Figure 3**(**b**), it takes 68.1 seconds to make nylon airbags fill with CO2 and provides 42.1 N buoyancy for AUV. The design of added buoyancy can bring 7.47 kgw of underwater vehicle to the surface (assume that the full load displacement is fixed). With this technology, we can install the appropriate number of gas cylinders and airbags in accordance with different displacements of AUV accurately and conveniently.
