Design On Intelligent Electric Actuator

At present, design on intelligent electric actuator is becoming a hot spot in the area ofinternational process control. As is known to all, intelligent electric actuator which is widely used inthe industrial automation control system is the important component controlling and driving thevalve. Intelligent electric actuator which implements centralized control, automatic control andremote control to the valve, is the important part of pipe network system.In the past years, our country gave more attention to the design on electric actuator, haddesigned many kinds of multifunctional electric actuators, resulting in generally improving thequality of electric actuator and expanding the functions. However, the reliability, stability,sensitivity and precision of all most of electric actuators are not very good. In addition, there are notany good protective ways or communication technologies for them, so we can only perform localcontrol operation on these devices. Therefore, it is significant for us to design a new multifunctionalintelligent electric actuator.Firstly, intelligent electric actuator is analyzed in detail by this paper which introduces theover-all structure of the system. By this way, we can know deeply the structures and functions ofcontroller and actuator, and master the operation principle of intelligent electric actuator to providethe direction to hardware and software design.Secondly, this paper provides the hardware design scheme of control system based oncombination of the requirements of intelligent electric actuator control system and understanding ofoperation principle of wireless radio frequency (RF) communication. For hardware circuit design,the selection of CPU and wireless RF chips, circuit of power supply, circuit of SCR driving, circuitof input and output interface (including circuit of A/D converting, circuit of position detection,circuit of motor overheating detection protection and alarm indication, circuit of the keywordinterface and state control output, circuit of D/A converting and V/A, circuit of LCD display) andcircuit of wireless RF communication are introduced in detail. For the software design, the paperprovides the main flow block diagram of system and each functional module scheme according tothe requirements of intelligent electric actuator.Finally, in order to improve the reliability and stability of control systerm to make good use ofintelligent electric actuator, introduction of the key technologies on intelligent electric actuator aregiven in detail by this paper.Output valve position can be accurately controlled and measured precisely, calculated anddisplayed by this new designed intelligent electric actuator. It makes combination of servo amplifierand actuator through CPU and communication technology, achieving the control functions of local limiting protection, overload (torque) protection, motor overheating protection, emergency stopprotection, indication of output valve, failure alarm and so on. The actuator can be controlled bylocal and remote operation, and it is easy to finish the manual operation and switch between manualand automatic operation without any disturbances.