| Company attempts to design a system for on-line monitoring of temperature and sag of the high-voltage transmission lines. In this system, the current-transformer with separate style is adopted for power supply. In this case, the efficiency of power supply is determined by the coupling tightness of the two sections of current-transformer. During the installation process, the real-time detection data is transmitted to worker on the ground by wireless transmission, and then people can judge whether the transformer is well coupled. Since the height of power tower ranges from 20 meter to 50 meter, constructors on tower have to talk with workers on ground through wireless communication. Because of the high-risk operations on tower, constructors should only carry some essential tools. Therefore, the functions of voice communication and data communication are tried to be integrated into the detection device, which makes the installation more convenient and efficient.First, the feasibility of IEEE 802.15.4-based real-time voice communication is discussed in detail in this paper. Second, considering the transmission characteristics of JN5168(NXP) module, the suitable application protocol for voice communication is developed. Then, using the 32-bit embedded processor PIC32MX(Microchip) as core unit, the hardware platform for real-time voice communication is designed including speech-acquisition-and-coding chip WM8960, wireless transmission module JN5168 and corresponding peripheral circuits. At last, based on Speech compression encoding and decoding algorithm(ADPCM), digital signal sequence algorithm and frame encoding and decoding algorithm, the device successfully implements the real-time voice communication. The experimental results and test results show that the developed detection device meets the expected requirements and has the traits of low-cost, low-complexity, high-transmission-rate, high portability, better real-time, etc. |
PDF Full Text Request