Pneumatics - Theory
theory of pneumatics is pretty straightforward from a robot wars perspective.The
most common use of pneumatics is in the weapons systems and in this situation
you want to move as much gas from point A to point B as quickly as possible.
The greater volume of gas moved in a given time, the more energy can be
passed through the system. The gas creates movement by being at a different
pressure to the atmosphere outside it. (Imagine a water pipe - pour water
in one end with your finger over the other end and the water doesn't flow.
Remove the finger and there is a pressure difference between the ends which
causes the water to move through the pipe).
Gases are complex in their movement and use, but for our purposes, we need to take note of the pressure the gas is stored at; the pressure the gas is to be used at and the transistion between these two states. Robot wars allows a maximum pressure of 1000 pounds per square inch (psi) for gases in a pneumatic system. Most commercial pneumatics equipement operates at around 145 psi. This is fine because it means you can keep gas in a heavily compressed at 1000 psi and decompress smaller amounts as required by the system. This does, however, mean that a device is needed to perform this function and in doing so, the velocity at which the gas is moving is reduced. The art is to minimise the losses in the system and create a highly efficient system. Note also that the speed of sound through a gas is a reflection of how much gas can be moved through a hole at pressure. CO2 is slower than air. Hydrogen and helium are faster.