Modern control systems are becoming more and more complex and sophisticated. It is not a driving control technology that can satisfy various control functions of the system. Electric actuators are mainly used in applications requiring precise control. Flexibility requirements in automation equipment are constantly increasing. The same equipment often needs to adapt to the processing needs of workpieces of different sizes. Actuators need multi-point positioning control, and precise control or synchronous tracking of the speed and torque of the actuators. Trace, these traditional pneumatic control can not be achieved, and the electric actuator can be very easy to achieve such control. It can be seen that pneumatic actuators are more suitable for simple motion control, while electrical actuators are mostly used for precise motion control.

In terms of technical performance, the advantages of pneumatic actuators mainly include the following four aspects:

(1) It has large load and can be used in high torque output applications.

(2) Quick action and quick reaction.

(3) Good adaptability to working environment, especially in flammable, explosive, dusty, strong magnetic, radiation and vibration working environment, superior to hydraulic, electronic and electrical control.

(4) The motor is easily damaged when the stroke is blocked or the valve stem is tied.

The advantages of electric actuators include:

(1) compact structure and compact volume. Compared with pneumatic actuators, electric actuators are relatively simple in structure. A basic electronic system includes actuators, three-position DPDT switches, fuses and some wires, which are easy to assemble.

(2) The driving source of the electric actuator is very flexible. Generally, the on-board power supply can meet the demand, while the pneumatic actuator needs the air source and the compression driving device.

(3) The electric actuator has no danger of air leakage and high reliability, while the air compressibility makes the stability of the pneumatic actuator slightly worse.

(4) There is no need to install and maintain various pneumatic pipelines.

(5) The load can be maintained without power, while the pneumatic actuator needs constant pressure supply.

(6) Because no additional pressure device is needed, the electric actuator is quieter. Usually, if the pneumatic actuator is under heavy load, it is necessary to install a muffler.

(7) In pneumatic devices, it is usually necessary to convert electrical signals into gas signals, and then into electrical signals. The transmission speed is slow, so it is not suitable for complex circuits with too many series of components.

(8) The electric actuator is superior in control accuracy.

Pneumatic actuator

In fact, pneumatic and electric systems are not mutually exclusive. Pneumatic actuator can simply realize fast linear cyclic movement, simple structure, convenient maintenance, and can be used in various harsh working environments, such as explosion-proof requirements, multi-dust or humid conditions. But when the force increases rapidly and needs precise positioning, the electric driver with servo motor has advantages. For applications requiring precise, synchronous operation, adjustable and specified positioning programming, electric driver is the best choice. The electric drive system composed of servo or stepping motor with closed-loop positioning controller can supplement the shortcomings of pneumatic system.