JPH09197038A - Display circuit of sonar device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the grasping of situation in a B scope display which is disadvantageous for grasping the situation of a target and ship where an active sonar device is installed. SOLUTION: With the speed and course of a target as parameters, a CPA calculation circuit 6 superposed a trace (CPA cursor trace) 22 of a time-predicted position when viewing the target from the ship on a B scope display of a CRT 11 for display, thus assisting in grasping situation. When they are close to each other, a U-shaped display 22 results and closest contact (CPA) is indicated. This trace is called a CPA cursor trace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display circuit of a sonar device, and in particular, it emits a sound wave in water to receive a reverberant sound from a target object, and based on the result of this reception, an image is displayed on a B scope to search for the target. The present invention relates to a display circuit of an active sonar device for detecting.

[0002]

2. Description of the Related Art Generally, in an active sonar apparatus, a received echo is displayed on a CRT as a video image to search, detect and track a target. At this time, if the target is relatively close to each other in the tracking state, the sonar operator needs to grasp the target and the opposition of the own ship and perform the tracking operation.

As a mode of image display on the CRT in this case, there is a display system as shown in FIG. Figure 5 (a) shows PP
This is an I display system, in which the radial direction is the distance and the circumferential direction is the azimuth direction. With this PPI display system, it is easy to grasp the opposition of the ship and perform a tracking operation.

However, this PPI display system has a problem in that the image becomes dense at a short distance and the accuracy in the case where the cursor is aligned with the target is deteriorated, and the PPI display system is compatible with the CRT display of the TV scan system which is currently the mainstream. In recent years, the B scope display has been adopted because of poor performance.

FIG. 5 (b) shows this B scope display, in which the horizontal axis represents the azimuth and the vertical axis represents the distance.

[0006]

This B-scope display has a azimuth that is linear on the horizontal axis, making it difficult to intuitively grasp the opponent's attitude. PPI can be installed separately or by switching the conventional PPI.
Was displayed to complement this. For this reason, the operation becomes complicated and it is necessary to add a scan converter or the like.

Incidentally, in Japanese Patent Laid-Open No. 3-245075,
There is a method to display estimated positions of past and future target objects, but when the target is fixed, the relative position locus (history) with the own ship is displayed in conjunction with the direction and distance cursors, and the target is fixed. A technique is disclosed that is used to assist in determining whether it is moving or moving.

Also in the technique disclosed in Japanese Patent Laid-Open No. 3-245075, the target temporal predicted position cannot be displayed while taking advantage of the above-mentioned advantage of the B-scope display (affinity with the CRT display of the television scan system). There is.

An object of the present invention is to provide a B-scope display in which it is difficult to intuitively distinguish between the target of the conventional method and the reaction of the ship.
Using the target course and speed as parameters, the temporal predicted position of the target from the past to the future is calculated, and by displaying this trajectory superimposed on the image, a sonar device that can assist the sonar operator in grasping the attitude It is to provide a display circuit.

[0010]

According to the present invention, there is provided a display circuit of a sonar device for displaying a locus of a detected target position in a B scope display, wherein the detected target position is used as a base point. Means for calculating a target position viewed from the ship at regular time intervals from the course and speed of the ship and the target course and speed input from outside, and the calculated target position. A display circuit of a sonar device is obtained, which includes a display unit that is superimposed on a display and displayed as a locus.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention will be described. The target temporal predicted position is calculated using the target course and speed as parameters, and the calculation result is displayed as a trajectory superimposed on the B scope. The calculation of the temporal predicted position of the target from the past to the future is set by the operator estimating the motion parameters (course, speed) of the own ship, which is self-explanatory, based on the currently detected target position (azimuth, distance). The estimated position in the past and the estimated position in the future are geometrically obtained using the target motion specifications (course, speed) as parameters, and the coordinate position corresponding to the B scope display is obtained.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, a reverberant sound from a target or the like is converted into an electric signal by the wave receiver 1 and A / D converted by the receiver 2, and then a large number of directional preformed beams are formed. The preformed beam reception signal is subjected to signal processing such as correlation calculation by the signal processor 3 to obtain the video signal 101.
Is output to the video generation circuit 7.

The image generation circuit 7 interpolates and scans the image signal 101 corresponding to each preformed beam to generate an image luminance signal corresponding to the B scope display, and writes it in the image memory circuit 8. The video luminance signal is converted into an analog signal by the D / A conversion circuit 9 read corresponding to the scanning of the CRT, and is displayed on the CRT 11 in the B scope format via the video amplifier 10.

On the other hand, when the sonar operator moves a cursor symbol mark (not shown) on the CRT screen by operating a trackball or the like, the target position determining circuit 5 matches the target image 30 with the target image 30, and operates the hook. Direction of
The distance value is given to the CPA calculation circuit 6 as the target azimuth / distance information 104.

In the CPA calculation circuit 6, based on the target estimated course / speed information 102 output from the parameter setting circuit 4 by the key operation of the operator and the past and present course / speed information 103 of the own ship, The future estimated position of the relative position of the target viewed from the ship is calculated, and CPA (Close
st Point Approach) trajectory information 106
To the video generation circuit 7.

In the image generation circuit 7, the CPA trajectory information 10
The luminance signal for displaying the symbol mark determined based on 6 is generated by superimposing it on the above-mentioned image luminance signal, written in the image memory circuit 8, and similarly displayed on the B scope (for example, a locus). 22). CRT screen 11
Reference numeral 21 above indicates the course of the ship.

Next, the method of calculating the CPA locus will be described with reference to FIGS. Now, assuming that the relationship between the own ship 20 and the target 30 is as shown in FIG. 2A, the course of the own ship 20 is C0, the speed is V0, and that of the target 30 is CT, VT. Further, when the own ship position at the time t0 of the calculation is X00, Y00 and the target ones are X0T, Y0T, the own ship 20 changes to the target 30.
The relative position when viewed is represented by the following equation on the Cartesian coordinates (B scope display) as a function of time.

The relative azimuth B0T of the target is B0T = tan ^-1 {XT (t) -X0 (t)} / {YT (t) -Y0 (t)}-C0 (1), and the target relative distance ROT is, ROT = a [{YT (t) -Y0 ( t)} 2 + {XT (t) -X0 (t)} 2] 1/2 ... (2).

However, YT (tn) = VT.multidot.tn.cosCT + YOTY0 (tn) = V0.tn.cosC0 + YO0XT (tn) = VT.tn.sinCT + XOTX0 (tn) = V0.tn.SinC0. , T = t0, t1, ..., Tk, ..., Tn.

BOT and R represented by the above equations (1) and (2)
If the temporal prediction trajectory with OT is displayed on the B scope as a continuous bright line or an intermittent symbol mark, it becomes a CPA trajectory display. FIG. 2B shows an example thereof, and is an example of the CPA locus display 22 when the velocity of the target 30 is changed to VT1 to VT3 while keeping the course of the target 30 constant.

The target 30 is the own ship 20 as shown in FIG.
In the case where the vehicle is approaching from the upper left and is passing in front of the ship, the U-shaped C as shown in Fig. 2 (b)
The PA track display 22 is displayed. In addition, the locus at this time is the closest point (Closest Point of Approa).
ch), it is called “CPA”.

Further, with the target speed VT being constant, the course C
When T is changed, the CPA locus is displayed as shown in Fig. 4 (a), and when both the course and the speed are changed, Fig. 4 is displayed.
As shown in (b). These CPA trajectories are schematic.

When the CPA locus is displayed with intermittent symbol marks, it is usually performed every detection cycle (sonner transmission cycle). For example, if the maximum range of the distance (vertical axis) on the B scope display is 2 kiloyards, then approximately 5
CPA trajectory calculation is performed at intervals of seconds, and symbol marks are displayed at positions of 5 seconds, 10 seconds, 15 seconds, ....

Therefore, the sonar operator determines the relationship between the actual locus of the detected position and the CPA locus as the detection progresses.
It is possible to observe on the image, and it is possible to perform an appropriate operation by grasping the target motion (course, speed), the positional relationship with the CPA (closest contact point), the time relationship, and the like.

[0026]

As described above, according to the present invention,
With the parameters of the motion parameters (route, speed) of the ship that are obvious based on the currently detected target position (azimuth, distance) and the motion parameters of the target (route, speed) estimated and set by the operator, By geometrically obtaining the estimated position in the past and the estimated position in the future and displaying it on the B-scope display so as to be superimposed on the received image, the disadvantage of the B-scope display is difficult to intuitively grasp the reaction between the ship and the target. It has the effect of being able to make up for it.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 (a) is a diagram showing a relationship between a ship and a target, and (b).
FIG. 6 is a diagram showing an example of B scope display of a CPA locus in this case.

FIG. 3 is an explanatory diagram for calculating CPA trajectory information.

FIG. 4A is a diagram showing another example of a B scope display of a CPA locus, and FIG. 4B is a diagram showing another example of the same.

5A is a diagram showing a PPI display, and FIG. 5B is a diagram showing a B scope display.

[Explanation of symbols]

 1 receiver 2 receiver 3 signal processor 4 target parameter setting circuit 5 target position determination circuit 6 CPA calculation circuit 7 video generation circuit 8 video memory circuit 9 D / A circuit 10 video amplifier 11 CRT (B scope display) 20 self Ship 21 Own course 22 CPA trajectory display 30 Target

Claims (2)

[Claims] 1. A display circuit of a sonar device for displaying a locus of a detected target position in a B scope display,
Based on the detected target position as a base, from the course and speed of the ship itself, and further from the target course and speed input from the outside, means for calculating the target position viewed from the ship at regular intervals. And a display means for displaying the calculated target position as a locus by superimposing it on the B scope display. 2. The display circuit of a sonar device according to claim 1, wherein the display means changes at least one of the target course and the speed to display a trajectory of the target position. .