Study On The Experimental Platform Construction Of DC Speed Control System And Object Modeling

In the modern society that computer technology and control technology develop rapidly, digital control technology has a wide range of applications for its advantages of accuracy, stability and fast calculation speed in controlling and it can realize complex algorithm. Therefore, it is very important to master the method of digital controller design. In practical control system digital controller is designed mainly according to analog controller rather than taking direct design method, which does not give full play to the advantages of digital control.In this background, this paper puts forward the construction scheme of experimental platform based on the DC speed control system. The experimental platform is used to research the direct design method of digital controller, and is constructed on the basis of digital DC converter6RA70.6RA70takes speed-current double closed-loop structure. Because of the speed controller has main adjustment function in speed controlling, and the speed loop has less strict requirement in sampling time than the current loop, this paper proposed a scheme that move the speed regulation part to external controller. For6RA70is not good enough for the open question, the author completed the task that removing speed controller by using the configurability of6RA70software function module and some necessary hardware connection. To chose a PLC as the controller and PC as the host computer to monitor the system. The direct controller design experiment and digital controller program realization experiment can be completed on the designed platform. In order to increase the system transient time to study the dynamic characteristics, this paper increased the design of the inertia load. In addition, this paper also gave an example of experiments.Because studying the methods of digital controller design is based on the model of the controlled object, this paper gave a research on modeling the DC speed control system object. Through the experimental results and the theoretical analysis to get the input and output characteristics of the controlled object in the actual system is different from that of the theory. The object is researched by the means of dividing the curve into3parts and identified by using least square. This model satisfied the engineering requirements after it verified by experimental data. At the end of the paper, it established BP neural network model based on a large amount of experimental data. This model has a high precision it verified by generalization of simulation results.