A pneumatic system uses compressed air to perform a certain task. You have definitely experienced such a system at a dentist or if you have been riding a bus across the city. The doors of the bus are closed and opened with such a system.
In robotics, the pneumatic systems are used to replace servo and electric motors. In other words, a pneumatic motor acts to move a certain load.
Such a system is simple. Inside of a pneumatic system is a cylinder piston that moves up and down to create pressure.
Even if a pneumatic system is simple, we rarely find a hobby project that uses pneumatic pistons to act on the arms, legs or other components of the robot.
The most common projects using pneumatic systems are in the film industry. Disney uses compressed air to move various movie characters. A pneumatic system is the best hardware to build a robot with realistic and fluid movements.
- simplicity. Any component of a pneumatic system can be simply changed. In addition, such a system works efficiently in comparison to electric or hydraulic motors.
- precision and good repeatability. The precision of a pneumatic system is approximately 2 mm with a repeatability of 0.02mm.
- even if it does not apply to a hobby project, a pneumatic engine can be used at extreme temperatures. The temperatures with minus may reach -40 Celsius degrees, while the temperatures with plus can reach 120 Celsius degrees.
- it is easy to replace a pneumatic piston in case of a malfunction.
- simple and clean. Using air as the main material for producing motion is much simpler and cleaner than a hydraulic system.
- the robotics enthusiasts who use pneumatic systems to drive various components do not have available a significant variety of hardware components. Moreover, it is quite difficult to obtain these components, at least in Europe.
- if such a system has air loss, the efficiency decreases a lot.
- the air compressor must run almost continuously even if there is no movement.
- noise and vibration. The air compressor produces a lot of noise and vibration compared to an electric or hydraulic system.
- efficiency. For high efficiency, the pneumatic system must correspond to a specific job. In other words, the same pneumatic piston can be used in another robotic project only if is adjusted.
- space. Space is a problem in most robotics projects. Such a system occupies quite a lot of space.
An example of a pneumatic system of a robot built at home
If you’re using electric current to move a robotic arm, you need servo motors, servo motor controllers and a microcontroller to control the servo motor controller. The system is simple and is found in almost all the DIY projects build at home.
For a pneumatic system, the list of components is long and costly. Let’s see what it’s all about:
- Air compressor: this device that produces noise and vibration is the basis for any pneumatic project. Considering the effects produced, it is necessary to mount it away from the sensors or video cameras. A compressor used by hobbyists would be that.
- Pressure Valve: This is a safety system for cases when the system pressure is higher than necessary.
- Connectors: To attach the components between them, you need connectors.
- Pressure Switch: this is a sensor that sends a signal to the compressor to stop when a certain pressure is reached.
- Air Tank: this keeps the air under pressure. If you have a system that consumes a lot of resources, you probably need more such tanks.
- Regulators: They regulate the pressure in the components of the system. If it is necessary to apply different pressures to certain components, you need more regulators.
- Pressure Gauge: it indicates the system’s pressure.
- Valves: these have a role similar to the transistors in an electrical system. They have the ability to change the direction of air flow and can be controlled in both directions.
- Hand Valves: these are manually controlled and are generally used for user’s safety.
- Fittings: these are the parts that connect all components of the system. These are in different sizes and shapes.
- Air Tubing: In an electrical system we have wires to transport the current from the source to the consumer. In a pneumatic system, we need pneumatic air tubing.
- Air Cylinders: this is the equivalent of the electric motor and uses pressure to produce the piston movement to accomplish a certain task.
The list of a pneumatic system is long, much longer compared to an electrical system. From the cost point of view, an electrical system has a clear advantage in front of a pneumatic system. From an efficiency point of view, the pneumatic system has an advantage compared to an electric system.
What types of action element do you intend to use in your projects? Electric or pneumatic?