The Study Of The Parameter's Detection And Control Methods Of Smooth-flux Pump

Abstract Constant-flux pump is a kind of precise liquid machine. It is widely used in petroleum, petrochemical, pharmaceuticals, refined chemistry and other domains of scientific and research. In the exploration and development of petroleum, constant-flux pump is an important device which is used to simulate the parameter of the stratum liquid. In the using process, some domestic pumps don't have constant flux. The main reason is that their control precision of output flux and output pressure is low. And the price of the oversea product are very high. So exploiting constant-flux pump which has high precision has more economic significance. So this article built the mathematic model of the pump's output. And the control technologies and stepper motor drive technologies are adopted based on micro processing technology. The solution to boost up the quality of the pump's constant flux and constant pressure is put forward. The precise control and steady output of the pump come true.In this article, first, a brief introduction to the background of the pump's exploiting and application is made. And the main content, technology route and the organizational structure of the thesis is also expatiated. And then, after the subject framework of the article is introduced, the content of four aspects is expatiated: the basal theory of the control of the constant flux and constant pressure, the design of micro processing system based on ADuC831, the research of constant-flux model and constant-pressure model and the realization of control methods of the two models, the design of the stepper motor drive circuit and control circuit. In the aspect of basic theory, the academic knowledge which is used in the control of constant-flux pump is introduced in detail, such as linear regression model, recursive least squares and adaptive control technology. In the design of the micro processing system based on ADuC831, the pressure signal is acquired by the ADC in the ADuC831. The speed of the stepper motor can be controlled by the PWM function in the ADuC831. In the design of the pulse distribution circuit, the quality of the low frequency and high frequency of the stepper motor is ensured. In the design of the constant-flux, the flux and the speed is found satisfy the linear regression model, after it is adjusted according to the output pressure, the precise control parameters of stepper motor can be get. So the feed-forward control can be realized by adjusting the speed of the stepper motor, and the pump will output a precise and constant flux. In the design of constant-pressure model, the mathematic model of the head of the pump can be estimated with recursive least squares algorithm. And the output of the controller can be calculated on line. So the adaptive PID control to the output pressure can realize. At last the software and hardware designed was integrated, and combined with the mechanical parts. The sample can be obtained. Some experiments are done to test the quality of the pump. The result is that the quality is very good. Now the pump has been used in some correlative projects in Instrument Research Institute.