The Design Of The Portable Rotating Machinery Condition Monitoring System

Rotating machinery is widely applied in all walks of life, many of which are the most key equipments of the production process and the main objects for the enterprise to carry out the condition monitoring. Strengthen the diagnosis and monitoring of these apparatus is of great significance, such as making sure the efficient operation, increasing the production, improving the product quality and improving the economic efficiency of enterprise. While traditional equipment vibration monitoring system is an independent diagnostic testing device, which is composed of the sensors, signal processing circuits, test results show and control panel. The main function is signal acquisition and control, analysis and processing, expression of results and output. These functions are given by the equipment manufacturers, are all achieved by hardware circuits and firmware and generally in fixed constitution. It is the function form of hardware that determined the traditional fault diagnose system is of poor flexibility, which can be defined, manufactured and maintained only by equipment manufacturers, but users can not change its structure and function arbitrarily. In addition, because of the high cost of the development and maintenance of traditional fault diagnosis system, the long period of the development and technology update, the system is very difficult to work with the other apparatus and usually work independently and manually. It has limitations obviously and is inconvenient to use on the complex and multi-parameter occasions. There's a large amount of information in the running course of rotate machinery devices which can help people to judge the running states of all kinds of rotate machinery. Base on the above, a rotating machinery state monitoring system based on vibration analysis was designed and developed, which is a virtual machine in a sense. It consisted of computer, application software and apparatus hardware. The computer hardware and apparatus hardware were organic integrated by the software, combined the strong data processing and analysis capacity of computer and the measurement and control capacity of apparatus together. The data processing, display, storage and wave analysis were achieved by the application software.The thought of the system is that, collecting the vibration signal by vibration sensor in the operation of rotating machinery equipment, filtering and magnifying by hardware circuits, A/D converting, and then processing the data after it was uploaded to the computer through the USB interface. The PC can set the corresponding parameters of data collector, such as sample rate, the number of channels, etc. The analysis and processing of signal and the relative waveform analysis diagram were achieved by the application software. Then through the relative waveform analysis and spectrum analysis judging the condition of the machinery equipment.The main content of this paper includes:Firstly, discussed deeply of the common cause of malfunction, the vibration characteristic and means of vibration diagnosis to rotating machinery, introduced the approaches of time domain and frequency domain analysis of vibration signal, proposed the design idea.Secondly, the hardware design of the system was introduced. The design idea of master-slave single-chips to work together was taken, the master single-chip control the main system hardware and the slave single-chip control the collection of data, the purpose of which is to improve the speed and the precision of the data collection. Filter circuit design, amplify circuit design, ADC unit design, control unit design and USB interface unit design were introduced in detail.Afterward, the system firmware programming and the function modules of application software were introduced. The system firmware program consists of the single-chip control program, the interrupt program and USB communication program, etc. The function modules of system consists of time domain graph, spectrum graph,3D waterfall chart, detailed spectral analysis, cepstrum analysis, autocorrelation analysis and Bode plots.At last, the rotating monitoring system was tested. It shows the design of the system was successful, and the system can monitor the vibration signal of various kinds of large rotating machinery equipments, can find the failures of kinds of machinery equipments, with the virtues of fast response, low cost, high reliability and stable performance.