Research And Design Of Electric Actuator Controller Based On Fieldbus

Electric actuator is a kind of terminal unit in the auto control field; it has a prodigious influence on running safely, reliability and performance of adjustor. At present there are a lot of disadvantages in most domestic electric performer such as these products'control can't consider sensitivity and stability, it has low performance for being controlled by analog signal and being droved on-off directly by asynchronous Motor. Electric actuator control system model is difficult to certain because it is affected by blind area, variable motor permanent and uncertain industry status, so it can't achieve good performance in usual PID. Most electric actuator which only receive analog signal can't communicate with host control system(for example host computer,DCS,FCS), they are difficult to process digital distributed control. Maintenance is difficult and the degree of integration is low. Debugging and maintenance are difficult, and the worker can't adjust parameter basing fact in spots. Foreign electric actuators have advantage performance, but they are applied restricted because of its expensive. Therefore, it is very important to design domestic new electric actuator.First of all, this thesis researches control technology of electric actuator, designs a kind of new embedded multi-CPU controller according to controller requires. Secondly, this thesis analyses position control and velocity control, and proposes fuzzy PID algorithm of velocity adjustor. It introduces the design process detailedly, and simulates the algorithm in MATLAB. The result of simulation shows that it can consider sensitivity and stability.Lastly, this thesis research multi-CPU controller hardware circuit based on high power MCU AT89C55, and designs main control circuit, keyboard and display circuit, motor droved circuit, Fieldbus communication circuit and data acquisition circuit. These modules are designed independent cards which achieve data sharing by extending dual-port RAM. The thesis designs software with Module Architecture. All function module software are designed independently and are scheduled by main control module. Experimental results show the effectiveness of the method, and this kind of controller with compact configuration and high reliability has improved electric actuator performance, it proved to achieve anticipated result.