| 摘要 |
PURPOSE:To obtain a fishing net monitoring device which is capable of an inclined angle of a detecting part, as well, by controlling the modulation of a detecting information transmitting ultrasonic wave in accordance with inclination of an ultrasonic detecting part installed to a fishing net. CONSTITUTION:An inclined angle of an ultrasonic detecting part which is provided with upper and lower side ultrasonic transducers 21, 22, etc. and is installed to a fishing net is detected by an angle sensor 8, and a time constant of a monostable multivibrator 9 which moves in accordance with a reference oscillator 7 is controlled. Subsequently, by inclined angle information converted to time information through a differentiating circuit 10, a monostable multivibrator 13, etc., an ultrasonic carrier wave FM oscillating circuit 25 is controlled, and a transmitting ultrasonic wave modulated in accordance with detecting information and inclined angle information by the transducers 21, 22 is transmitted from a carrier wave transducer 27. In accordance with this reception, the inclined angle of the detecting part is also recorded in a fishing net monitoring device of a fishing boat. Accordingly, data required for the following operation, such as the inclined angle of the detecting part whose receiving state becomes worse, etc. can be obtained easily and exactly. |
