JPH0266486A - Speed measuring instrument for submarine craft - Google Patents

Abstract

PURPOSE:To improve measuring accuracy by analyzing the frequency of sea reverberation and finding out the absolute speed of a submarine craft including the influence of a tidal current on the basis of the analyzed result and the operation posture data of the submarine craft. CONSTITUTION:Depth data 111, track data 121 and inclined angle data 131 are respectively outputted from a depth sensor 11, a track sensor 12 using a gyroscope, etc., and an inclined angle sensor 13 in a sensor part 1 and supplied to a speed calculator 5. An acoustic sensor part 2 projects a transmission output transmitted from a transmitter/receiver 22 to the front of the submarine craft in the traveling direction as an acoustic pulse from a transmitter/receiver 21. The transmitter/receiver 21 is arranged on the head of the submarine craft, receives projected acoustic pulses including an underwater target and sea buttom, underwater and sea level reflections as sea buttom, underwater and sea level reverberation and utilizes the sea level reverberation to measure the speed of the submarine craft including the influence of a tidal current. Since the speed of the submarine craft can be measured by utilizing the sea level reverberation, the absolute speed including the influence of the tidal current to the submarine craft can be obtained.

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a speed measuring device for underwater vehicles, and
- A speed measuring device for an underwater vehicle equipped with a sound sensor and configured to measure and output the speed of the underwater vehicle necessary for tracking a target while navigating under the sea.

[Conventional technology]

Conventionally, this type of speed measuring device for an underwater vehicle calculates the speed from the scree rotation speed of the underwater vehicle.

[Problem to be solved by the invention]

The conventional underwater vehicle speed measuring device described above calculates the speed from the rotational speed of the screw, so it can only determine the speed relative to the tidal current, and therefore the actual speed that takes into account the influence of the tidal current cannot be obtained. First, it has the disadvantage that it introduces errors in position determination during tracking navigation of an underwater vehicle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speed measuring device for an underwater vehicle that can eliminate the above-mentioned drawbacks and measure the actual speed taking into account the influence of tidal currents.

[Means to solve the problem]

The speed measuring device for an underwater vehicle of the present invention is a speed measuring device for an underwater vehicle that is mounted on an underwater vehicle that navigates under the sea with its own blades and acquires speed information of the underwater vehicle. and a sensor unit that acquires data regarding the course and the inclination angle of the traveling direction with respect to the water surface; an acoustic sensor section that receives the signal; a frequency analyzer that analyzes the frequency of sea surface reverberation received by the acoustic sensor section; and a Doppler frequency of the emission frequency of the acoustic pulse emitted from the acoustic sensor section based on the analysis result by the frequency analyzer. A speed calculation that calculates the speed of the underwater vehicle based on a Doppler frequency calculator that calculates, data regarding the depth, course, and inclination angle obtained by the height section, and the Doppler frequency output from the Doppler frequency calculator. It consists of a container.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and is a diagram of an underwater vehicle. lt, the course, and the sensor data for acquiring data on the inclination angle of the traveling direction with respect to the water surface1. Acoustic sensor unit that emits acoustic pulses with a predetermined direction in the direction of travel of the watercraft and receives echoes from the sea, including sea surface reverberations2. Frequency analyzer 30 that analyzes the frequency of sea surface reverberation received by the acoustic seven-stage part 2 Doppler frequency calculation that calculates the Doppler frequency of the emission frequency of the acoustic pulse emitted from the acoustic sensor section 2 from the analysis result by the frequency analyzer 3 Vessel 4. and data regarding the depth, course, and inclination angle acquired by the sensor unit 1 and the Doppler frequency calculator 4
The submersible vehicle is configured to include a speed calculator 5 which calculates the speed of the underwater vehicle based on the Dob 2 frequency outputted by the submersible vehicle.

The sensor unit 1 also has a depth center t-11. Course Seven Nbu 12. A tilt angle sensor 13 is provided to output depth, course, #, and tilt angle data, respectively.

The acoustic sensor part 2 includes a transducer 21 that transmits acoustic pulses into the sea and receives the echoes thereof, and generates and receives signals transmitted and received via the transducer 21. The acoustic sensor unit 2 utilizes an acoustic guidance device installed in an underwater vehicle for target tracking.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

The depth sensor 11 of the sensor unit 1 receives depth data 11.l
Further, course data 121 and inclination angle data 131 are outputted from the course centimeter 12 and inclination angle sensor 13, which utilize a gyro or the like, respectively, and are supplied to the speed calculator 5.

The acoustic sensor section 2 emits the transmission output output from the transceiver 22 from the transceiver 21 as an acoustic pulse forward in the traveling direction of the underwater vehicle. The transducer 211 is disposed at the head of the underwater vehicle, and the emitted acoustic pulses are transmitted to targets in the ocean, including the ocean floor.

Reverberations from the sea and from the sea surface are also called submarine reverberations.

A feature of the present invention is that waves are received as underwater reverberations and sea surface reverberations, and of these, the sea surface reverberations are used to measure the speed of an underwater vehicle, including the influence of tidal currents. It is used to ensure the functionality of a Dogura sonar.

Diagram M2 is an explanatory diagram showing how underwater reverberations are captured by underwater vehicles.

The underwater vehicle 10 travels underwater in the direction of travel at a depth [h].

Assume that the ship is traveling at a speed of V. This underwater vehicle 10
The t# pulse emitted from the 0 head generates a sea surface reverberation #R as a reflection from the sea surface W, and is captured by the transducer 21 at a sea surface reverberation incident angle θ with respect to the cruising direction.

This sea surface reverberation R is captured after T SMP of the following equation (1) after sending out the acoustic pulse, and the transceiver 22 captures this T SMP
Later, sampling for sea surface reverberation input will begin.

(1) In equation (1), h is the image of the underwater vehicle 10 and is provided from the depth sensor 11, and δ is the transmitted beam depression angle and is provided from the speed calculator 5, which will be described later. where C is the speed of sound in the ocean. (
1) Equation means that the propagation distance of sea surface reverberation is 2.
h a secδ is the center, so °C its propagation time is TSM
This means that P. In this case, the depth is usually
Although the position of the underwater vehicle 10 is shown as a dot point, the size of the underwater vehicle 10 is sufficiently small compared to the operating depth, so in the case of FIG. It can be considered almost the same as.

Now, after the acoustic pulse is transmitted, sampling for inputting sea surface reverberation is started after this T SMP, and after a time corresponding to the acoustic pulse width has elapsed, sampling is finished and sea surface reverberation is input. After transmitting the acoustic pulse, the underwater vehicle 10 changes its position by 7 feet until TSMP.
The influence of SMP is appropriately corrected by a glogram built into the reception system of the transceiver 22 based on the attitude data of the underwater vehicle 10.

The sea surface reverberation has sufficiently larger reflected energy than the underwater reverberation, and the thus captured sea surface reverberation signal 22 is then supplied to the frequency analyzer 3.

The frequency analyzer 3 performs frequency analysis on the input sea surface reverberation signal by fast Fourier transform or the like, and supplies the analysis result to the Doppler frequency calculator 4 .

The Doppler frequency calculator 4 calculates the Doppler frequency of the sea surface reverberation signal based on the difference between the frequency of the transmitted acoustic pulse and the input frequency analysis result, and uses this Doppler frequency data 4.
01 to the velocity calculator 5. The velocity calculator 5 supplies the depth data 111. Course data 121
．． Tilt angle data 131 and Doppler frequency data 401
Based on this, the speed V of the underwater vehicle 10 is determined by the following equation (2).

(2) In equation (2), V is the speed of the underwater vehicle, fd is the Doppler frequency, fo is the frequency of the transmitted acoustic pulse, and δ is the depression angle of the transmitted beam. δ is depth data 111° course data 11
2 and the tilt angle data 113, and this δ is also provided to the above-mentioned transceiver 22.

In this way, the speed of the underwater vehicle can be calculated in total by 11111 by using the ocean WJ reverberations, and the speed thus obtained is an absolute speed that takes into account the influence of the tidal current on the underwater vehicle.

〔Effect of the invention〕

As explained above, the present invention analyzes the frequency of sea surface reverberation,
Based on this and the operational attitude data of the underwater vehicle, it is possible to determine the absolute speed of the underwater vehicle, including the influence of tidal currents.

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing how sea surface reverberation is captured by an underwater vehicle.

1... Sensor section, 2... Acoustic sensor section, 3... Frequency analyzer, 4... Doppler frequency calculator, 5......・Speed calculator, 11・
... Depth sensor 12 ... Path 1 length - 13 ... Inclination angle sensor, 21 ...
Transmitter/receiver, 22...Transmitter/receiver.

Agent Patent Attorney Susumu Uchihara

[Brief explanation of the drawing]

Claims (1)

[Scope of Claim] A speed measuring device for an underwater vehicle that is mounted on an underwater vehicle that navigates under the sea and acquires its own speed information, comprising: a depth and a course of the underwater vehicle, and a traveling direction with respect to the water surface; a sensor unit that acquires data regarding the inclination angle of the underwater vehicle; an acoustic sensor unit that emits acoustic pulses with a predetermined direction in the traveling direction of the underwater vehicle and receives reverberant sounds from the sea including sea surface reverberation; a frequency analyzer that analyzes the frequency of sea surface reverberation received by the acoustic sensor section; and a Doppler frequency calculator that calculates the Doppler frequency of the emission frequency of the acoustic pulse emitted from the acoustic sensor section from the analysis result by the frequency analyzer. , a speed calculator that calculates the speed of the underwater vehicle based on the data regarding the depth, course, and inclination angle acquired by the sensor unit and the Doppler frequency output from the Doppler frequency calculator. Features: Speed measuring device for underwater vehicles.