JPH0632629Y2 - Course and speed display - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a course and speed display device for estimating and displaying a target course and speed from information of a sensor for detecting the position of a target such as a radar or a sonar.

[0002]

2. Description of the Related Art Conventionally, an apparatus for estimating and displaying a course and speed of a target (for example, a ship) in a radar image display has, for example, a structure as shown in FIG. -The target observation position is measured from the target radar video signal obtained for each antenna scanning period of the radar 1, and the target course is determined based on the target observation position signal output from the target detection means 2 in the motion estimation means 3. And the velocity are estimated, the vector generating means 5 generates a vector signal from the target course and velocity signals output from the motion estimating means 3, and the display 7 displays the vector signal output from the vector generating means 5. It is displayed superimposed on the video signal.

FIG . 5 shows an example of the display screen of the display unit 7, and targets 9a, 9b, ...
..Target 9a, 9b, ... 9e
Are displayed by vectors 10a, 10b, ... Here, the respective directions of the vectors 10a to 10e represent the course of the respective targets 9a to 9e, and the respective lengths of the vectors 10a to 10e represent the velocities of the respective targets 9a to 9e.

By the way, the radar video signal contains clutter noise and receiver noise in addition to the target signal, and the target signal also has fluctuations. The signal contains an error. Therefore, the motion estimating means 3 uses a cyclic filter such as a Kalman filter or an α-β filter in order to stably estimate the course and velocity, or the observation time is different.
It was necessary to perform a smoothing process by applying a moving average to the course and speed obtained from the position change of the points and the time difference, or by combining the two.

[0005]

However, in such a conventional display device, when the target is performing a uniform linear motion, the course and speed are well estimated and a stable vector is displayed. However, the response when the target is changed or the gear is changed becomes very slow, and the vector is displayed as if the uniform linear motion continues despite the change of the needle or the change in speed, and the course and speed indicated by the vector are displayed. However, there was a problem in that the actual route and speed were significantly different from the target.

FIG . 6 is a diagram for specifically explaining the above problem and shows an example of a vector display of a course and a speed when a target, which is performing a constant-velocity linear movement, suddenly changes its needle. In FIG. 6 , L is the trajectory of the target motion, and Po and P1 are the target positions of the motion process. At the point Po, where the target is moving at a constant speed, the vector 10 correctly represents the target course and speed. At the point P2 where the target is changed, the course and speed represented by the vector 10, particularly, the course is greatly delayed from the target change in course, which is significantly different from the actual target course and speed.

One for solving such a problem
As a method, the radar data file disclosed in JP-A-49-4491 is used.
Ruta device has been proposed. In this filter device, the target of
Fixed with excellent smoothness as a channel to predict movement
There are two channels, an immediate channel with excellent response characteristics.
Fixed when the prediction error of the fixed channel becomes large.
Clear the channel's forecast data and predict on the immediate channel
I will replace it with the data.

That is, the following process is repeated. A fixed channel is used to predict the target position based on radar data.
Measure and display vector of speed and course. Predicted position with fixed channel and actual position with radar
Error and determine whether the error exceeds the threshold
It Specifically, the distance error Δρ, the threshold Sρ, and the angle
The degree error Δθ is compared with the threshold value Sθ to determine whether any one of Δρ> Sρ Δθ> Sθ continues three times.

When it is judged that there is a prediction error, the fixed check
Erase the position and speed predicted by the channel, at that time separately,
Replace with the position and velocity predicted on the immediate channel.
Therefore, if it is determined that there is a prediction error in the fixed channel,
The vector display is based on the predicted position and velocity in the immediate channel.
The display can be temporarily switched to the following display. However, such a radar data filter device
In that case, it will not occur if the target changes
Predicted position and velocity of fixed channels with excellent smoothness
Error with the predicted position on the responsive immediate channel
Temporarily replaced with speed to reduce and improve accuracy
Can be done, but real-time replacement by
When the error from the position disappears, the fixed channel prediction
I got back, for example, the display vector of the target while changing needles,
Display status based on position and velocity predicted on fixed channel
And the display status based on the predicted position and speed in the immediate channel.
State alternately and repeatedly while changing needle and changing gear
There is a problem that the torque display is not stable.

Further, even if the prediction accuracy is improved, the target is changed.
Whether or not the gear has been changed depends on the target display vector on the display screen.
You can't judge unless you keep watching the state of. However, on the display screen, for example, as shown in FIG.
The target facing the ship 15 at the center of the plane is the target 9a,
There are multiple targets like 9e, and there are multiple targets like this.
On the other hand, (a) the target ship judged that it was an escape ship and started changing needles.
Or, alternatively holding vessels and whether to judgment continues to hold the track, field that started the veering determines that (b) the target ship itself Collision Ship
In this case, the evacuation started in either the right or left direction.
Or, the child judged by the continuous monitoring of vector 10a~10e
Is quite difficult and hard to judge. This
Therefore, even if the prediction error can be reduced, the goal is enough to change the course.
Only after you have completed the
It is impossible to know the movement tendency and the ship operator can avoid the collision.
It is a big problem when making a disconnection.

The present invention has been made in order to solve the above problems, and estimates a course and a speed that quickly follow an actual target motion even if a target needle change or gear shift is performed. It is an object of the present invention to provide a course and speed display device capable of displaying.

[0012]

In order to achieve this object, in the present invention, there is provided a first motion estimating means having an excellent smoothing characteristic for estimating a target course and speed from a target observation position signal, and a target. Second motion estimating means having excellent response characteristics for estimating the target course and speed from the observed position signal of the second motion estimating means, and the first motion estimating means and the second motion estimating means.
Calculate the deviation of the constant value, and this deviation is smaller than the predetermined reference value.
At the end, it is judged that the target is not changing the needle or shifting, and the reference
When the value exceeds the value, the needle change gear shift detection means for determining that the target has changed needle or the gear change, and when the needle change gear change detection means has determined that the target has not changed needle or gear change, the first motion estimating means having excellent smoothing characteristics The target course and speed estimated by is displayed, and when it is determined by the change needle shift detection means that the target has changed needle or changed gear, the target course and speed estimated by the first motion estimating means having excellent smoothness characteristics are displayed. In addition, the display control means for displaying the target course and speed information estimated by the second motion estimation means having excellent response characteristics is provided.

[0013]

According to the present invention having such a structure, when a stable course and speed are displayed for a target performing a constant-velocity rectilinear motion, if a change or a shift is recognized, the motion of the motion is recognized. The trend is displayed promptly, and the target
The direction of change of needle can be clearly presented to the operator.

Further, in the present invention, when it is determined that the target needle change or gear shift has occurred, not only the target course and speed estimated by the first motion estimating means are displayed,
Since the target course and speed estimated by the second motion estimating means are displayed at the same time, when the needle change gear shift detecting means erroneously determines that the needle has changed or changed gears even though the target has not changed needle or changed gears. In comparison with a device that switches and displays only the target course and speed estimated by the second motion estimating means, the influence of incorrect determination is extremely small.

[0015]

DETAILED DESCRIPTION FIG. 1 is - in the case of the dust sensor les - block diagram illustrating one embodiment of taking the present invention in an example case of displaying by estimating the target of course and speed in da video display Is. In FIG. 1, 1 is a radar, 2 is a target detecting means, 3a is a first motion estimating means, 3b is a second motion estimating means, 5 is a vector generating means, 6 is a needle change gear detecting means, and 7 is an indicator. is there.

The first motion estimating means 3a and the second motion estimating means 3b estimate the target course and speed from the target observed position signal output from the target detecting means 2, and the first motion estimating means 3a is smooth. The second motion estimation means 3b has a characteristic that the degree of smoothing is large but the response is slow, and conversely, the degree of smoothing is small but the response is fast. The first motion estimating means 3a and the second motion estimating means 3b can be realized by using, for example, an α-β filter. For example, a one-dimensional α-β filter is represented by the following equation. Xp (k) = Xs (k-1) + Vs (k-1) .ΔT Xs (k) = Xp (k) + α {Xm (k) -Xp (k)} Vs (k) = Vs (k -1) + β {Xm (k)-Xp (k)} / ΔT Xm: Target observation position Xs: Target smooth position Xp: Target predicted position Vs: Target smooth velocity ΔT: Observation time interval α: Position Smoothing constant β: Velocity smoothing constant To estimate the target course and velocity using this α-β filter, for example, the target observation position is set to the orthogonal coordinate system (XY
Coordinate system) and α-in each of the X and Y directions
The β filter may be applied to calculate the target smoothing velocity in the X direction and the Y direction, and coordinate conversion may be performed to convert to the course and velocity.

Here, the characteristics of the α-β filter are α, β
If the value of is made small (close to 0), the degree of smoothing becomes large and stabilization can be achieved, but the response becomes slow, and conversely α,
When the β value is increased (close to 1), the degree of smoothing decreases, but the response becomes faster. (For the characteristics of this α-β filter, see, for example, DEMAYIATIS “COMPARISON OFAN
α-β AND KALMAM FILTER IN TRACK WHILE SCAN RADAR
S ”(MASTER'S THESIS). ) Therefore, α-β used in the first motion estimation means 3a
If the constants α and β of the filter are α1 and β1, and the constants α and β of the α-β filter used in the second motion estimating means 3b are α2 and β2, respectively, α1> α2 and β1> β2 should be set. The first motion estimating means 3a and the second
The motion estimating means 3b obtains the above characteristics, the first motion estimating means 3 estimates a stable course and speed, and the second motion estimating means 4 estimates the course and speed that well follow the target needle change or gear shift. Can be done.

As is clear from the above characteristics,
If the target is a needle change or a gear change, the first motion estimating means 3a
There is a deviation between the course and speed estimated in (3) and the course and speed estimated in the second motion estimating means 3b. Therefore,
The needle change gear shift detection means 6 receives the course and speed signals which are the outputs of the first motion estimation means 3a and the second motion estimation means 3b as input, and compares the both directions and speed signals to obtain a deviation value,
The target variable gear shift is detected by collating with a preset specified value d. That is, when (deviation value) ≤ (specified value d), it is determined that the target is not changed or changed gears, and when (deviation value)> (specified value d), it is determined that the target is changed or changed gears.

In the vector generating means 5 functioning as the display control means, if it is determined that the target is not changing the needle or the gear is not changed, according to the determination result of the needle change gear shift detecting means 6, the first
A vector signal representing the target course and speed estimated by the motion estimating means 3a is generated, and when it is determined that the target has changed needles or speed changes, the target course and speed estimated by the first motion estimating means 3a are calculated. A second representing the target course and speed estimated by the second motion estimating means 3b together with the vector signal representing the second
Generates a vector signal of.

The display 7 superimposes and displays the vector representing the speed and the course as a target in the radar image display based on the output signal of the vector generating means 5. FIG. 2 shows an example of vector display of the course and speed according to the embodiment of FIG. In FIG. 2, 10 is a vector that displays a target course and speed, 12 is a second vector that is displayed when a needle change or gear change is determined, L is a trajectory of a target motion, and P ₀ and P ₁
Is the target position of the motor process.

First, at the point Po where the target is performing a uniform linear motion, the variable needle shift detection means 6 determines that (deviation value) <(specified value d) and the target is not changing the needle or shifting gears. A vector 10 representing the stable course and speed estimated by the first motion estimating means 3a is displayed. At the point P1 where the target has changed needle, (deviation value)> (specified value d) and it is determined that the target has changed needle or changed gear, and the vector 1 representing the course and speed estimated by the first motion estimating means 3a.
In addition to 0, the vector 12 representing the course and velocity that well follows the change in the motion estimated by the second motion estimating means 3b is displayed, and the tendency of the target motion is quickly shown.

FIG . 3 shows the velocity and course vector according to the present invention.
Fig. 5 shows an example of the target display, using the same goal as Fig. 5 as an example.
ing. In Fig. 3, the target toward the ship 15 at the center of the screen
Are targets 9a and 9e, but for targets 9a and 9e
Vector by the first motion estimating means 3a having excellent smoothing characteristics
Second motion estimation with excellent responsiveness in addition to 10a and 10e
Vectors 12a and 12e by means 3b are displayed simultaneously.
Has been.

For this reason, the operator of the target 10a
Immediately after the evacuating vessel was judged and the evacuating operation started to the left
It is possible to judge, and the following target 9e is different from the own ship.
Is starting to take the course that becomes
You can judge immediately. In the above embodiment, the method for comparing the course and speed signals of the outputs of the first motion estimating means 3a and the second motion estimating means 3b is used as the needle change gear shift detecting means 6, but, for example, the first motion estimating means 3a and When the α-β filter is used as the second motion estimating means 3b, the target predicted position Xp (k) in the α-β filter of the first motion estimating means 3a having a particularly slow response when the target changes the needle or changes gears.
It is also possible to adopt a method in which the deviation value is compared with a preset prescribed value as in the above embodiment, paying attention to the deviation occurring at the target observation position Xm (k).

Further, although the above embodiment has described the case where the radar is used as the sensor for detecting the target position, the present invention is similarly effective when the other sensor such as a sonar is used. It is something.

[0025]

As described above, according to the present invention, the target motion state is detected, and only the course and speed information estimated by the estimation means having excellent smoothing characteristics is displayed according to the state. Or, by displaying simultaneously the course and speed information estimated by the estimator with excellent response characteristics in addition to the course and speed information estimated by the estimator with excellent smoothness characteristics, a stable indication of the course and speed can be obtained. The target movement state such as the change of the needle or the gear shift is promptly shown while the target movement state can always be faithfully grasped.

Therefore, for example, in the case of a ship, the movement of another ship can be grasped quickly and accurately to prevent a collision accident, which has an effect of greatly contributing to safety during navigation.

[Brief description of drawings]

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

FIG. 2 is an explanatory view showing an example of vector display of course and speed according to the present invention.

FIG. 3 shows a vector display of velocity and course according to the present invention .
Explanatory diagram showing an example

FIG. 4 is a block diagram showing an example of a conventional course and speed display device.

FIG. 5 is an explanatory diagram showing an example of display by a conventional device.

FIG. 6 is an explanatory diagram showing a problem of vector display of a course and a velocity of a conventional device.

[Explanation of Codes] 1: Radar 2: Target detecting means 3a: First motion estimating means 3b: Second motion estimating means 5: Vector generating means 6: Hand change gear shift detecting means 7: Display 10: Vector 12: Second Vector 2 of 2 : Own ship

Claims (2)

[Scope of utility model registration request] 1. A course and speed display device for estimating and displaying a course and a speed of the target based on position information of the target measured by a target detecting means, wherein a course and a speed of the target are calculated from the position information of the target. A first motion estimating means having excellent smoothness characteristics, a second motion estimating means having excellent response characteristics for estimating a target course and velocity from target position information, the first motion estimating means and the second motion estimating means. Motion estimation means
Find the deviation of a constant value, and the deviation is smaller than the predetermined reference value
If the target is not changing needles or shifting,
When the target is changed or when the target is not changed, it is estimated by the first motion estimation means. The target course and speed are displayed, and if it is determined that the target has changed needle or changed gear, the first
Course, characterized by comprising display control means for displaying the heading and the speed of the estimated simultaneously <br/> the the course of the estimated by the motion estimation unit target and a speed second motion estimation unit target, the And speed display device. 2. The route and speed display device according to claim 1, wherein the display control means estimates the first motion when the target change gear shift detection means determines that the target is not changed or changed gears. The target course and velocity estimated by the means
If the target change or shift is determined by the change needle shift detection means, the target course and speed estimated by the second motion estimating means are displayed by the first vector and A course and velocity display device for displaying a target course and velocity estimated by the second motion estimating means by a second vector.