|A Study on the Detection Algorithm of an Advanced Ultrasonic Signal for Hydro-acoustic Releaser
Young-Jin Kim, Kyung-Moo Huh*, and Young-June Cho
International Journal of Control, Automation, and Systems, vol. 6, no. 5, pp.767-775, 2008
Abstract : Methods used for exploring marine resources and spaces include positioning a probe under water and then recalling it after a specified time. Hydro-acoustic Releasers are commonly used for positioning and retrieving of such exploration equipment. The most important factor in this kind of system is the reliability for recalling the instruments. The frequently used ultrasonic signal detection method can detect ultrasonic signals using a fixed comparator, but because of increased rates of errors due to outside interferences, information is repetitively acquired. This study presents an effective ultrasonic signal detection algorithm using the characteristics of a resonance and adaptive comparator Combined with the FSK+ASK modulator. As a result, approximately 8.8% of ultrasonic wave communication errors caused by background noise and transmission losses were reduced for effectively detecting ultrasonic waves. Furthermore, the resonance circuit’s quality factor was enhanced (Q = 120 to 160). As such, the bias voltage of the transistor (Vb= 3.3 to 6.8V) was increased thereby enhancing the frequency’s selectivity.
Keyword : Detection algorithm, marine instrument, probes, remote control system, ultrasonic signal.