| With the rapid development of computer communication technology, the host computer monitoring technology at home and abroad has been thoroughly studied and widely used. In this paper, it takes the speed control research of step motor at home and abroad as a research background, for the problem that the mechanistc study in the field of speed control of the blood pump is still little, analyzes and discusses a varity of speed control models which suitable to the speed increaing of the axial flow blood pump, and takes VB6.0 as a softwore control platform to solve the speed models,and discrete these models to acquire speed control parameters,then through the PC serial communication to pass parameters to the microcontroller in real time,and utilmately realizes the speed curves'planning.In addition, for the current experimental system exists outside the human workload, low level of intelligent control and on-line detection imperfect, using the serial communication between PC and intelligent instrument or SCM, establishes the host computer line detection system based on VB6.0. And in accordance with the features of temperature and flow, it takes the appropriate digital filter to do the signals filter analysis and processing,which can meet the system's requirements. The main research contents are introduced as following:1. According to the characteristics of the data object of serial communication between PC and MCU AT89S52, PC and the Turbine Flow Meter, provides different communication protocols, designed a different data frame structure.In the communication process, sequential polling method is used to ensure the data structure integrity and compact.2. In the VB6.0 platform for control analysis, it proposes a general formula for solving speed control parameters of axial flow blood pump. It establishes basic curve model and a three sections S-curve speed-rising-control model controlled by three initial conditions parameters. Speed control parameters are obtained by discrete solution through host computer for more research.3. Based on the dynamics model of blood pump, Runge-Kutta algorithm is used to solve and analysis the model and the result that time-domain curves are obtained and the distribution of the stable point of speed has gotten. Based on the principle of Hermite interpolation, two discrete methods are proposed such as equal time law and equal speed law. Finally, the specific method of blood pump speed control is realized to achieve the purposes in strong controllable and higher accuracy.4. Based on the temperature measurement circuit making up of digital sensor DS18B20 and AT89S52, a temperature acquisition system is established. And it establishes flow acquisition system in the host computer which takes LWGY-15C Turbine Flow Meter as the core. Using ADO object accesses to ACCESS database to implement the operation and treatment of the data. The entire detection system has achieved acquisition reliable, functional and strong controllable.5. It built detection experimental device of a large gap magnetic drive system. Drive performance of the speed control models such as the Baisc Curve law and Blood Pump Three-sections S-Curve law are compared by test,and proves that the S-curve is better.Measurement temperature of the silicon steel sheet inside electromagnet and outlet flow of blood pump acquisition experiments have been done to get the warming curves, instantaneous and cumulative flow curve in the different speed. Acquired signals have been through filter analysis, and accuracy of flow measurement has been analyzed. Using the cumulative method of indication of the overall flow measuring accuracy of less than 5%.It demonstrates the feasibility of the host computer system, and provides valuable tools and methods in detection. |
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