Design Of Self Validation Turbidity Sensor Based On Virtual Instrument

With the rapid development of industrial technology, the application of sensor is extensive more and more. All kinds of sensors are used in different domain and different systems. As we know that sensors in automatic control and information systems are very important devices, they play the pivotal roles. The higher level of automation system is, the more dependence on the sensor's accuracy is. The Sensors as the only approach of information acquisition which is the basis of system decision, there is no doubt that it plays a very key role in those automated, intelligent systems. The accuracy of sensors measurements directly affects the outcome of the operation, systems analysis, the correctness of the decision-making.The traditional sensors support the value of the signal which we want to measure. Because the sensors we used will be in all sorts of fault, there are some uncertainties, the sensor's fault will makes the whole system disable. Systems will be controlled by the wrong information and run incorrectly even brings catastrophic consequences. The problem must solve is to improve the Reliability of sensors. it is the key issue we are facing.The type of self-validation sensor which is mention in this thesis is identified by the traditional sensor is that it can not only support the value of the signal we want to measure, but also support the value's degree of validation. The self-validation sensors are on the basis of self-recognition algorithm using its own output of the sensor signals. This new intelligent sensor will be a very good solution to the problem the above mentions. With high reliability, high stability, high fault-tolerant features such as monitoring and control system for the signal acquisition provides a good solution, it brings us very important significance in control engineer domain.We choice the PC and data acquisition card (DAC) as the platform of the self-validation turbidity system research. In detail describing is that the first use PC applications driver NI Company's product (6024-E Series Data Acquisition Card) which is driven through the PCI bus by LabVIEW to get the acquisitions on measure value. Include three phase turbidity values one phase temperature values of the water to be measured. And then send the collecting data back to the PC and the LabVIEW application do the operation for wave analysis, processing, integration; the final results will be displayed on the intuitive GUI (Graphic User Interface). In the arithmetic facet we use a virtual instrument technology with signal processing technology (ARMA Model), intelligent control algorithms (BP Neural Networks) to achieve the multi-turbidity Sensors real-time fault diagnosis, data fusion output, the final object is to reached a intelligent turbidity sensor system which not only give users the high-reliability turbidity values, but also to provide users with the uncertainty value of the turbidity values.At the present time, with the rapid development of science and technology, industrial automation level increasing very fast. Many high precision and high accuracy sensor will be need. We need to build high reliability and high-precision control system; a necessary condition is high reliability and high-precision sensor. So the self-validation sensor technology which is described in this paper has practical application worthiness. At the same time, the technology and arithmetic of fault diagnose, data integration is not only worthiness for the turbidity sensor, and it can be use for reference to improve the reliability of other sensors.