The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
권호 표지
DOI QR코드

DOI QR Code

A study on wideband underwater acoustic signal amplifier design for generating multi-frequency

다중 주파수 재생을 위한 광대역 수중 음향 신호 증폭기 설계 연구

  • Received : 2017.04.04
  • Accepted : 2017.05.30
  • Published : 2017.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

The problem that occurred in the design/fabrication/testing of the wideband transmitting power amplifier for an embedded active SONAR (Sound Navigation and Ranging) system operating underwater was analyzed and the solution of the problem was proposed in this paper. Wideband acoustic SONAR systems had been developed in order to improve the underwater detection performance. The underwater acoustic transmission system had been also developed to achieve the wideband SONAR system. In this paper, the wideband acoustic transmission signal was generated using a 2 Level sawtooth type Class D PWM (Pulse Width Modulation) which was not complicated to implement. When the sonar signals having two or more frequencies were simultaneously generated, parasitic frequencies were added to the original signals by integer multiples of the frequency difference of the original signal. To cope with this problem, we proposed a way to remove the parasitic frequency from the source signal through modeling and simulation of the implemented power amplifier and PWM control hardware using MATLAB and Simulink.

본 논문에서는 수중에서 운용하는 임베디드 능동 음향탐지 시스템에 적용하기 위한 광대역 송신 전력 증폭기 설계/제작/시험 과정에서 발생된 문제를 분석하고 해결방안을 제시한다. 최근 수중음향 분야에서도 탐지 성능을 향상시키기 위해 광대역 소나(Sound Navigation and Ranging, SONAR) 신호처리 연구가 진행되고 있으며 이를 위한 광대역 수중음향 송수신 장치 개발이 이루어지고 있다. 본 논문에서는 임베디드 시스템 특성상 복잡하지 않고 구현이 간단한 2 레벨 톱니파 형태의 Class D 급 PWM(Pulse Width Modulation) 신호 생성 방식을 사용하여 광대역 수중음향 신호를 생성한 이후에, 송신 증폭기를 통하여 다양한 형태의 송신 파형을 재생하고 수중에서 실험을 하는 과정에서 두가지 이상의 주파수를 가진 소나 신호를 동시에 재생한 경우, 원신호에 두 신호의 주파수 차의 정수배만큼 더해진 기생 주파수가 나타나는 현상이 발생하여 원하지 않은 송신 음원이 재생되는 문제가 있음을 발견하였다. 이러한 문제점의 원인을 분석하기 위해 MATLAB 및 Simulink를 이용하여 송신 하드웨어 및 PWM 제어 과정을 모델링하고 시뮬레이션 하였으며, 시뮬레이션을 통해 문제점을 재현하고 해결방안을 제시한다.

Keywords

References

  1. S. C. Butler and F. A. Tito. "A broadband hybrid magnetostrictive/ piezoelectric transducer array," Oceans 2000 MTS/IEEE Conference and Exhibition. 3, 1469-1475 (2000).
  2. M. P. Hayes, P. J. Barclay, P. T. Gough, and H. J. Callow, "Test results from a multi-frequency bathymetric synthetic aperture sonar," OCEANS, 2001. MTS/ IEEE Conference and Exhibition. 1682-1688 (2001).
  3. P. Chapman, D. Wills, G. Brookes, and P. Stevens, "Visualizing underwater environments using multifrequency sonar," IEEE Computer Graphics and Applications. 19, 61-65 (1999).
  4. K. H. Kim, D. S. Cho, and J. C. Kim. "High frequency acoustic scattering analysis of underwater target" (in Korean), Journal of the Society of Naval Architects of Korea 42, 528-533 (2005). https://doi.org/10.3744/SNAK.2005.42.5.528
  5. J. W. Shin, W. J. Kim, D. W. Do, D. H. Lee, and H. N. Kim. "Fast wideband active detection and doppler estimation using the extended replica of an HFM pulse in active SONAR systems" (in Korean), Journal of the Institute of Electronics and Information Engineers 51, 11-19 (2014).
  6. X. Song, P. Willet, and S. Zhou, "Range bias modeling for hyperbolic-frequency-modulated waveforms in target tracking," IEEE Journal of Oceanic Engineering, 37, 670-679 (2012). https://doi.org/10.1109/JOE.2012.2206682
  7. Y. Doisy, L. Deruaz, S. P. vanljsselmuide, and S. P. Beerens, "Reverberation suppression using wideband doppler-sensitive pulses," IEEE Journal of Oceanic Engineering, 33, 419-433 (2008). https://doi.org/10.1109/JOE.2008.2002582
  8. D. H. Jang, G. H. Choe, and M. Ehsani, "Asymmetrical PWM technique with harmonic elimination and power factor control in AC choppers," IEEE Transactions on Power Electronics, 10, 175-184 (1995). https://doi.org/10.1109/63.372602
  9. B. G. Cho, H. C. Jin, and K. W. Lee, "Real-time implementation of variable-frequency sinusoidal PWM with harmonics suppressing characteristics" (in Korean), The Transaction of the Korean Institute of Electrical Engineers 1071-1073 (1992).