JPH01288787A - Measuring method of position of steaming body - Google Patents

Abstract

PURPOSE:To enable the measurement of the position of a steaming body being a target by a receiver group set in one point substantially, by receiving a steaming sound of the steaming body by three Geophones having maximum sensitivities in the directions of three axes intersecting one another perpendicularly and by one nondirectional receiver. CONSTITUTION:A nondirectional receiver HO is disposed at the origin O of coordinates, while Geophones Gx-Gz are disposed in the vicinity of the origin O on the axes x, y and z of rectangular coordinates so that the directions of the respective sensitivities being maximum coincide with the directions of the coordinate axes. A steaming sound emitted by a target is received by these devices. First, the respective azimuth angles are detected from the outputs of the Geophones Gx-Gz by an azimuth estimating element 12, and based on these angles, theta and phi of polar coordinates are determined or calculated. Then, the point of the nearest proximity is estimated from a change of theta with time. Besides, the frequency of the target sound is detected from the output of the receiver HO by a frequency estimating element 11, and based on the frequency, the speed of the target body at the time of the nearest proximity is estimated. A value (r) of the polar coordinates is calculated from these values by a position computing part 13.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention uses a small receiver to receive underwater sound waves emitted by a moving object, and processes the received signal. This relates to a positioning method for calculating the position of.

(Prior Art) Conventionally, as a method of measuring the position of a vehicle using a so-called passive method that only receives underwater sounds (travelling sounds) generated by the vehicle, a three-point measurement method shown in Fig. 5 has been used. Distance method (Tokuko Showa 54-
38910) and the triangular ranging method shown in Figure 6 have been used in the field of passive navigation. In Fig. 5, three receivers 1 to 3 are arranged in a straight line for the sound of navigation.
The difference in the propagation time of the sound waves from the vehicle V to the three receivers 1 to 3 is measured by a method such as determining the cross-correlation function between the received signals. The position of body V is determined. In Figure 6,
The navigation sound is received by two receiver arrays 1 and 2, and the arrival direction of the navigation sound is measured by each receiver array 1, 2, so the position of the vehicle V can be determined from these two angle information. is required.

(Problem to be Solved by the Invention) However, with any of the methods described above, positioning accuracy cannot be improved unless the intervals between the installation of the receivers or receiver arrays are greatly increased. There was a problem in that it was unsuitable for installation on other objects.

An object of the present invention is to provide a method that eliminates the above-mentioned problems and allows positioning of a mobile object using a group of receivers installed at one point in principle.

(Means for Solving the Problems) The present invention provides three
The navigation sound emitted by the vehicle is received by two geo-phonons (or directional receivers) and one omnidirectional receiver, and the frequency and incident azimuth of the navigation sound are measured. This is a positioning method for a vehicle that estimates the time of closest approach of the vehicle by observing changes, and calculates the position of the vehicle at that time.

(Function) In the present invention, the position at the time of closest approach is detected when the mobile object does not have a large velocity component in one axis direction of the geoffon.

First, the azimuth angles θ, θa, and θ2 are detected from the outputs of the receiver group, and based on these, the polar coordinates θ and ψ are determined or calculated.

Also, the time of closest approach is estimated from the change in θ over time.

Additionally, the frequency of the cruise sound is detected from the output of the omnidirectional receiver, and based on that, the vehicle speed at the time of closest approach is estimated.

Then, other polar coordinates γ are calculated based on the vehicle speed, θ and ψ.

(Embodiment) FIG. 1 is a layout diagram of a sensor according to an embodiment of the present invention, in which an omnidirectional receiver H8 is placed at the origin O of coordinates, and x
, geoion Gx・Gy, Q near the origin on the y and z axes
2 are arranged so that the direction of maximum sensitivity of each coincides with the direction of each coordinate axis. FIG. 2 is a diagram showing the positional relationship between the sensors and the vehicle, and shows the sensor group H8I GX + G71G7. shown in FIG. is placed near the origin O, and the position of the vehicle V is (X g yr
Z ), in the polar coordinate system (γ.

θ, ψ). Further, it is assumed that the vehicle V is moving at a speed V parallel to X@. These days.

A relationship is established.

FIG. 3 is a block diagram of the processing section according to the embodiment of the present invention, and the output signal of the receiver H6 is sent to the frequency estimating section 11, where the frequency f of the line spectrum component of the cruise sound is measured. . Furthermore, the output signal of the receiver H8 and the output signal of the geophonon Gz + Gy + Gz are sent to the direction estimation unit 12.
, where the directional knob buoy DIFAR (dir
ction finding and rangein
The angles θ, θa, and θ2 formed by the incident vector of the cruise sound and the x, y, and z axes are measured by the same process as g). The position calculation unit 13 calculates the frequency f of the navigation sound and the azimuth θ.
, θa, 02'f are input, their time changes are plotted, and the position of the vehicle is calculated using the following relationship. First, since the following holds true, θ=θ7 holds true according to equation (1). Next, if we set the point in time when the vehicle ■ crosses the yz-plane as t=o, then x==vt and rmin"=y+
If we put z, the following relationship holds true.

The vehicle V increases the speed V while emitting a sine wave with a frequency f0.
Assuming that it is moving in a straight line with a uniform velocity at
+-L) j'o (5). Here, C is the speed of sound. When the vehicle V is far enough from the sensor, Vr is V, and when it is at its closest approach (t=0), it is V
, 20, so if the time t=o can be estimated, 1 of the estimated value of the frequency of the navigation sound obtained by the frequency estimator
An estimate of the speed V of the vehicle can be obtained from the ratio of the value f at =0 (t=0) and the value f sufficiently before that, Ct = γ so).

Next, θ=02 obtained from the direction estimation section and equation (3
) is obtained as shown in FIG. 4 near 1=0, so by finding the minimum point of change in θ, an estimated value of bt=o can be obtained. Also, the gradient of ψ at this time is calculated by the third equation of equation (4) as v
/y, so if g is the estimate of the gradient of ψ in the vicinity of 1=0, then g= v/y
The relationship (7) holds true.

Estimates of θ and γ at 1=0 are expressed as Δ Let θ and r, mxn Since the relationship holds true, when combined with equation (7), △ An estimated value of the distance γ□,n can be obtained. Direction θ.

Since the estimate of ψ has already been obtained, we were able to obtain the measured values of the position (γ, θ, ψ) of the vehicle (1) at the time of closest approach (1=0). Furthermore, subsequent positions can be easily estimated.

In the above explanation, it is assumed that the cruising value moves parallel to the can be obtained.

(Effects of the Invention) As described above, according to the positioning method of the present invention, the position of a vehicle moving in a straight line at a constant velocity can be determined using a small sensor group placed at a single point. Since it can be measured with
It is highly effective if used as a positioning method for a moving vehicle when there are restrictions on the installation location of the sensor and it is not desirable to make sounds on its own.

[Brief explanation of the drawing]

FIGS. 1 to 4 are explanatory diagrams of one embodiment of the present invention,
Figure 1 is a layout diagram of the sensor, Figure 2 is a diagram explaining the relationship between the vehicle and the sensor, Figure 3 is a block diagram of the processing section, and Figure 4 is a diagram explaining the relationship between the moving object and the sensor.
The figure shows changes in polar coordinates θ and ψ, and FIGS. 5 and 6 are explanatory diagrams of the prior art, respectively. Ho...Omnidirectional receiver, Gz T Gy r Gz
...Geoffon, 11...Frequency estimation section, 12...
- Orientation estimation section, 13... position calculation section. Patent applicant: Oki Electric Industry Co., Ltd. Pro+77 I2I 3rd calculation t==0 (key iL1 te t11 no θ damn yohi "Y's consideration" 3, 111 distance is the 6th factor 1, Indication of the case 1988 Patent No. 8 No. 118156 2, Name of the invention Method for positioning a moving object 3, Person making the amendment Relationship with the case Patent applicant 6, Contents of the amendment (1) From the second line to the third line of page 7 of the specification, “(t=■
)” should be corrected to “(t=-)”. (2) Formula (6) on the same page of the same book is corrected as follows. Lower Blade\9 (3) In the 8th blind line 9 of the same book, σ that says ``cruising value'' is corrected to ``cruising object.''

Claims (1)

[Scope of Claims] Three geophones with maximum sensitivity in the directions of three mutually orthogonal axes and one omnidirectional receiver receive the traveling sound emitted by the mobile vehicle, A method of positioning a mobile vehicle, characterized in that the frequency and incident azimuth of the vehicle are measured, and the time change thereof is observed, thereby estimating the time of closest approach of the vehicle, and calculating the position of the vehicle at that time. Method.