Position Control of Pneumatic Cylinder Actuated by Low-Cost On/Off Valves Pulse Number Modulation

A replacement of a proportional valves with digital valves in pneumatic positioning systems possesses numerous attractive features that reduce the cost of actuation systems. Due to operation of pneumatic actuator with digital valves continuous switching mode is possible. Such mode decreases the system efficiency and valve durability. A large number of parallel connected valves is better to be controlled separately with a large number of opening state combinations because it decreases switching and increases efficiency. It also leads to better performance than the traditional control solutions based on digital valves, which are being widely adopted in industrial applications such as robotics, automobiles, manufacturing, and motion simulators. This paper introduces and investigates the benefits of the pneumatic actuation systems with a large number of parallel connected low-cost on/off valves acting in pulse number modulation.