Study On NC Technology Of Electric-Actuator Of Fluid Valve

The intelligent-electric-actuator is very important for remote distributed control of valves used in processing industry automation. Based on a review of present technology of electric-valve-actuator both domestic and aboard, and making use of available successful experience and the achievement of MCU technology, the study of the paper has achieved some results to improve electric-valve-actuator with intelligence-function and network-interface.The electric-valve-actuator is made up of controller and actuator, the study mainly works in the improvement of controller both in performance and functions, and also gives a necessary summarization for the actuator. The improved design of the control for valve-actuator is based on MCU of C8051F040 which produced by Silicon Laboratories. The controller provides some new functions, for example, setting parameters such as zero-point, and full-position setting, can be carried out both in local panel and remote panel on host computer in the network. The feed back signal of the valve-opening is obtained by step motor and MCU, and the signal is compared with the setting valve of that, the difference is calculated and used for control motor's running until the difference reduced to zero and the valve-opening is satisfying the setting value. The value of the valve-opening is displayed with LCD on local panel and can also be observed on the host computer connected to control network. Furthermore, advanced functions are also implemented in the design, such as over-heating protection, network communication, and fault-diagnosis. To get the design data for electric-actuator which satisfying the industry demand, a detailed analysis on the turning torque of most kinds of common valves is finished, and the fundamental data for the designing of intelligent valve controller is obtained..This thesis analyses and discusses the torque of valve in detail, based on the demand of valve to electric-actuator, it provides the necessary basic data and basis for the design of intelligent controller, to satisfy the request of actual production.The research in this paper is fallen into two portions, that is software and hardware work. A series of measurement with both hardware and software is employed to enhance the reliability and anti-jamming ability in industry field. Experiment result shows that the design is feasible, the system can realize the expected function.