| The oil is important strategic resource, and non-renewable. Well logging is an important part of oil exploration and development, and the logging data is main basis to evaluate the reservoir and estimate oil and gas reserves. Wireless logging is becoming a research hotspot because of the advantages of cost savings and easy to operation. Looking for a highly efficient wireless logging system and complete its hardware implementation, are very valuable in both theoretical research and engineering applications. Firstly, this paper studied Scattering, critical angle and steel transmission distance, choosing the right matching materials can reduce the Scattering energy, proved that the transmission of ultrasonic wave in the pipe does not exist a critical angle, and estimate d the distance of the ultrasonic transmission in pipes, proposed the transducer parallel equivalent model. Secondly this paper designed of the relay transmission mode, use the binary frequency shift keying modulation and differential detection demodulation, Discussed the overall framework and the internal module design in detail, Introduction power amplifier, matching circuit and the automatic gain control circuit design specially, embedded an asynchronous serial interface in DE2board to improve the entire system’s modular. At the end of the paper, we tested the Communication system, in the condition of Transducer transmission power is0.35W, error rate is0, data transmission rate is600bps, The communication system can spread1.2m in the air; it can transport data in a1.8m square wood accurately, although signal received by receiver is weaker; and the system can communicate in a2.4m steel pipe easily; Experimental results show that:it is feasible to use ultrasonic to transport data in the steel pipe wall. |
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