Application And Research Of High Frequency Signal Wireless Technology In Equipment On-Line Monitoring Field

The development of science and technology has been boosting the sensor, detecting circuit and digital transmission development into the direction of microminiaturized, intellectualized, integrated and lowly-consumed, particularly in computer technology, wireless communication technology, controlling technology, and the sensor technology. Moreover, the sensor technology and the radio technology are combined more and more closely with the latter's rapid development. The use of radio technology in constructing the wireless transmission module of data acquisition could reduce the cable connection between systems. And this wireless transmission module could be carried conveniently and applied widely, being able to be used outdoors or in some temporary monitoring situations besides under the ordinary conditions. Thus, it is significant in practice to study the miniaturized integrated acceleration sensor based on radio transmitting and receiving. The subject is based on the project "Portable diesel vehicles on-line monitoring, diagnostic apparatus" which is studied by Northeastern University Equipment Diagnostic Engineering Center for Shenyang Military Region, this paper designs a kind of high-frequency vibration monitoring sensor, then makes the wireless transmission of data come true.The first part of this paper proposes the composing of wireless communication system. The system's overall design is given according to the wireless system design principles and applications of the system. Then the paper detailed describes the selection and design about each part of the hardware. The system usually uses battery to supply energy. As a result, it is the core issue of saving the system energy from hardware circuit design to software. On the one hand, we choose micro-power chips:the sensor is ADXL105, a monolithic IC accelerometer made by ANALOG DEVICES Company. The wireless transceiver is a RF transceiver chip nRF401, which is produced by the Norwegian Nordic company and set transmit and receive integrated single-chip. Select C8051F530 single chip computer as MCU to convert analog to digital, control receiving, transmitting and store the data. It links to computers via RS-232 aerial port to transmit data to the central database, and joints to end-user's sensors through RS-232 serial port to collect data. On the other hand, it is also been thinking over about saving energy on communication protocol design. During idle time, the system can switch into low power mode. When the timer expires, it turns to active mode and another working cycle begins. During the period, if the system receives the synchronous signal sent by the PC, it will start to sample data, the send the data to PC. Finally, the experimental results are presented in this paper, proved that the design of this system and communication protocol could work as normal, and put forward new ideas to further improve the system.