1. Bus and network
Abroad, factory automation engineering technology based on industrial modeling technology has been developed rapidly in the past ten years. In order to adapt to this development trend, the electric actuator, as one of the automation instruments in automatic control, should also have a standard serial Communication interface and dedicated serial interface to enhance its interconnection capability with other control equipment. Only one cable or optical cable is needed to connect several, even fieldbuses, to field devices/instruments installed in the production process area. A serial, digital, multi-point communication data bus between automatic control devices/systems in the control room. As the development direction of the previous control system, the fieldbus enterprise network, with its openness, networking and other advantages, makes it possible to combine with Interent. Fieldbus technology makes electric actuators an inevitable trend. The application of fieldbus technology replaces the traditional 4-20mA analog signal, realizes the remote monitoring, status, fault, parameter information transmission of the electric actuator, completes the remote parameterization work, improves its reliability, and reduces the system and Engineering costs. At present, the influential fieldbuses mainly include PROFIBUS, FF, HART, CAN, etc. In fact, the existing foreign intelligent electric actuators generally have fieldbus interfaces, and some intelligent actuators with fieldbus interfaces have also been developed.
2. Digitization and intelligence
Intelligence is the current trend of all industrial control equipment. The low-priced single-chip microcomputer and new high-speed speed change will fully replace the control unit of the electric push rod based on analog electronic devices, thereby realizing a completely digital control system. The realization of full digitalization turns its hardware control into software control, so that advanced algorithms of modern control theory (such as optimal control, artificial intelligence, fuzzy control, neural network, etc.) can be applied to small electric actuators to improve Control performance. Traditional electric actuators are usually referred to as linear systems, consisting of amplification and integral interchange, but in fact, the execution will change significantly during execution. The application of parameter scheduling and model identification adaptive control will greatly improve electric actuators Control performance. Compared with pneumatic and hydraulic actuators, the wiring is simple, the function is powerful, and the reliable intelligent electric actuator will continue to expand the application range.
3. Miniaturization, mechatronics
The high integration of power electronics, the use of single-chip microcomputers and the use of some powerful modules have made the volume of small electric actuators smaller and smaller, and they have developed towards miniaturization and portability. At present, the intelligent electric actuator generally integrates the entire control loop with the electric actuator, thus simplifying the installation and debugging of the actuator; installing the entire control loop in the desktop field instrument, and reducing the signal transmission The influence of interference and interference on the system improves the reliability of the system.