Pneumatics are a useful category of robot components that provide simple and powerful linear motion. In short, pneumatics utilize compressed air to drive pistons (cylinders) that move in/out, which can be incorporated into robot subsystems for various purposes. In the past, 4311 has employed pistons to control the motion of claws, arms, climbing legs, and more. However, FRC has many regulations surrounding pneumatics, so it is important to understand both when and how to use them.
There are many cases in which linear movement of a robot subsystem is desirable. In these situations, pneumatic cylinders provide many advantages:
Pneumatic cylinders are incredibly strong, and can often supply more force than a motor.
The motion of pistons is straightforward and easy to employ in robot designs.
Pistons can be purchased in all manner of shapes/sizes, meaning they can be tailored to the design at hand.
Pneumatic systems are not incredibly robust, and have a tendency to break with wear and tear. Compressed air needs to be stored and delivered to pistons at different locations on the robot, and an incorrectly configured pneumatic system can lead to air leakages and pneumatic tube disconnections. To prevent failure during competition, it is paramount that all pneumatic systems be constructed with care.
Adding pneumatics to a robot takes a significant amount of time and space, because one needs to add a compressor, a PCM, air tanks, and solenoids along with the pistons themselves.
Pistons require compressed air to move and release compressed air upon movement. As such, performing too many piston actuations can deplete the air supply, requiring the compressor to refill the air tanks before the pistons can move again. On robots which make heavy use of pistons, multiple air tanks can be used to circumvent this issue, as they increase the maximum supply of air.