Research On Online Monitoring System For Mine Ventilator

For the modern needs of mine ventilator monitoring, a new type of low-power, integrated monitoring system of mine ventilator is designed in this thesis, which merges the embedded technology, modern signal processing technology, and object-oriented programming technology. The system includes three parts of signal acquisition and processing, data communication and computer control, which has realized the online real-time monitoring of mine ventilator pressure, flow, power and temperature and humidity parameters.In this thesis, measurement principles of the mine ventilator basic parameters and theoretical conversion formulas of parameters have been studied. Through the measuring method that uses of conversion between two parameters, the number of ventilator measured parameters is reduced. Characteristics of five types of sensor errors are analyzed. For characteristics of mine ventilator measured parameters, the proper sensor has been selected to reduce the measurement error of the whole system. For the noise of the system, the principle of wavelet denoising has been studied. The wavelet denoising method includes three parts of the wavelet decomposition and reconstruction method, wavelet threshold method and wavelet transform modulus maxima method. Comparing and analyzing features of these three methods, wavelet threshold method is selected and the determining method of the wavelet transform threshold is introduced. The conversion of mine ventilator measured parameters needs a lot of fast iterative operations, 32-bit high-performance microprocessor STM32F103VB is selected to improve the data processing capability of the system. To ensure real-time monitoring, the real-time operating systemμC /OS?II is used in the software design of the system. The circuit of data collection, LCD screen, keyboard processing, data storage, switch signal output control and communications module have been completed. Finally, the part of software design is introduced. Some flow chats of client software program which contains the data collection process, keyboard processing and communications module program are introduced. The PC software which is developed on the platform of Delphi7 is designed to complete the monitoring interface. In order to complete the data processing, display and recording, rich plugins of Delphi7 is used, and the multithreading pattern is adopted to complete data display ,real-time curves and so on while the data sampling and processing.The commissioning of prototype that is designed according to the above specification in the laboratory shows that the main technical parameters can achieve the design requirement. At the same time, data remote transmission by using communication interface of the system provides a simple and feasible design for the remote monitoring.