JP4474191B2 - Radar apparatus, radar detection signal processing and display method - Google Patents

Description

  The present invention relates to a radar apparatus that captures and tracks the position of a target from echoes included in a radar detection signal, and relates to a radar detection signal processing and display method in the radar apparatus.

  A pulse-type radar apparatus widely used for ships detects an object all around by rotating the antenna once in about 2 to 3 seconds. For the purpose of preventing a collision with another ship using such a radar device, an automatic collision prevention assist device (ARPA: Automatic Radar Plotting Aid) (hereinafter simply referred to as “ARPA”) is a large number of ships. It is mounted on.

FIG. 11 is a block diagram showing a schematic configuration of the signal processing unit 6 of the radar apparatus having the ARPA function.
The signal processing unit 6 includes an A / D conversion unit 61 whose input unit is connected to the reception unit 5 that generates a video signal including detected image information from the radar detection signal, and an input unit connected to the output unit of the A / D conversion unit 61. Are connected, the output unit is connected to the display unit 7, the input unit is connected to the antenna 3 and the azimuth sensor 102, and the output unit is connected to the A / D conversion unit 61. Is provided.

The A / D converter 61 converts a video signal based on the radar detection signal into digital detection data. The azimuth data generation unit 63 adds the antenna angle data from the antenna 3 and the bow direction data from the azimuth sensor 102 and outputs the antenna azimuth data to the echo detection unit 64 of the data processing unit 62. The echo detector 64 extracts (captures) an echo that can be regarded as a target from the detection data and the antenna orientation data, calculates a representative position of each target, and outputs the representative position to the echo selector 65. The echo sorting unit 65 selects only the target corresponding to the target currently being tracked (target target). That is, only one echo that can be regarded as the most relevant from a plurality of echoes is selected based on the estimated amount of motion of the target, and data related to the echo is output to the motion estimation unit 66.
The motion estimation unit 66 inputs the ship speed of the ship from the GPS receiver 101 and the bow direction of the ship from the direction sensor 102, and estimates the amount of movement of the target from the selected echo data. For estimating the momentum, an αβ tracker or a Kalman filter is used to calculate a new estimated position between the current predicted position and the selected echo position, and further, an estimated speed is obtained based on the calculation result.
Here, αβ tracking will be described. FIG. 12 is a conceptual diagram showing a tracking method of the αβ tracker, and shows a state in which the (n + 1) th scan is predicted from the nth scan as a linear predictor having a position smoothing constant α and a velocity smoothing constant β.
If the predicted position in the nth scan is P (n) and the measurement position is M (n), the tracking error E (n) is
E (n) = M (n) -P (n)
It is. The smoothing position S (n) and the smoothing speed V (n) are
S (n) = P (n) + αE (n)
V (n) = V (n−1) + βE (n) / T
Is required. Here, T is a sample period. From this, the predicted position P (n + 1) of the (n + 1) th scan is
P (n + 1) = S (n) + V (n) / T
Is required. At this time, if α = 0, the predicted position is set as the smooth position, and if α = 1, the measurement position is set as the smooth position. The smaller α is, the deeper the smoothing is performed.
In this way, the target target is tracked by repeatedly estimating the position and speed of the target target.
The display data generation unit 67 generates display data of the position of the target target (echo) and the amount of movement estimated by the movement estimation unit 66 and outputs them to the display unit 7.

  In such a radar apparatus, in addition to the target target (such as a ship) that is originally desired to be tracked, clutter such as the sea surface or rain may be superimposed, or the echo of the target target may disappear. Such superposition of clutter or disappearance of the echo may cause the wrong echo to be tracked or cause tracking accuracy to deteriorate. In some cases, transfer to a target other than the target target or lost (target target) A tracking error such as “lost” occurs.

Various radar apparatuses using an MHT (Multiple Hypothesis Tracking) method (multiple hypothesis tracking method) have been devised as means for correcting such tracking errors. This radar device of the MHT system, apart from the target target currently being tracked, within a predetermined area where the target target exists, possibly a target that may be a target target. Capture and track as. Then, the MHT radar device sets a predetermined judgment standard, and when the current target target does not conform to the judgment standard, the most probable hypothetical target target is switched to the current target target and tracking is continued. (For example, refer to Patent Document 1 and Patent Document 2).
Special Table 2000-505201 JP 2002-328164 A

  However, in the conventional MHT radar device, it is difficult for the user to determine that the target target has been switched for the following reason.

First, the distance between the target target that has been tracked so far and the hypothetical target target to be switched is not always short, and in most cases this distance is long. For this reason, when the display of the target target is switched, the display position of the target target on the display unit moves to a completely different position before and after switching.
Second, because there is a difference between the momentum of the target target before switching and the momentum of the target target after switching, there is no continuity of momentum before and after switching.

  Thirdly, since the target target on the display is the same marking by definition, when there are multiple target targets and there is a hypothetical target target for each of these target targets, This is because it is not known which target target has been switched.

  An object of the present invention is to provide an MHT radar device that can easily recognize this switching even when a target target is switched, and a radar detection signal processing and display method in the radar device.

  The radar apparatus according to the present invention includes a target motion estimation unit that estimates a motion of a target target, a target target switching unit that determines switching of the target target, and switches the target target according to the determination result; When the target target switching means switches the target target, the target target switching means switches display data of the target target, and includes display data generation means for generating intermediate display data between display data before and after the switching. It is a feature.

  Further, the radar detection signal processing and display method according to the present invention includes a step of estimating the motion of the target target, a step of determining the target target switching, and a step of switching the target target according to the determination result; A step of switching display data of the target target and generating intermediate display data between the display data before and after the switching when the target target switching means switches the target target.

  In these configurations, when the target target is switched, intermediate display data is output between the target target currently being tracked and the hypothetical target target. For this reason, the relationship between the target targets before and after switching is clearly displayed.

  In addition, the radar apparatus of the present invention specifically captures a target target using detection image data obtained from a radar detection signal, and detects a target existing in a predetermined area including the target target. Target capturing means for capturing; target motion estimating means for estimating the motion of the target target and the motion of the target in the predetermined area; the estimated momentum of the target target and the estimated momentum of the target in the predetermined area; A hypothetical target target detecting means for detecting a hypothetical target target from targets within a predetermined area, and a tracking quality evaluating means for evaluating the tracking quality of the target target using the estimated momentum of the target target And target target switching means for switching the target target to a hypothetical target target when the tracking quality of the target target does not conform to a predetermined standard, and further display of the target target When switching over data to the display data of the hypothesis targets target is characterized by generating an intermediate display data between the display data of the display data and the hypothesis targets target target target.

  The radar detection signal processing and display method according to the present invention specifically captures a target target using detection image data obtained from the radar detection signal, and within a predetermined region including the target target. Comparing the step of capturing an existing target, the step of estimating the movement of the target target and the movement of the target within the predetermined area, and the estimated momentum of the target target and the estimated movement of the target within the predetermined area Detecting a hypothetical target target from targets within a predetermined area, evaluating the tracking quality of the target target using the estimated momentum, and tracking quality of the target target is predetermined. When not complying with the standard, the step of switching the target target to the hypothetical target target and switching the display data of the target target to the display data of the hypothetical target target. When changing, it is characterized by comprising the steps of: generating an intermediate display data between the display data of the display data and the hypothesis targets target target target, the.

  In this configuration, at the time of switching, intermediate display data is output between the target target currently being tracked and the hypothetical target target. For this reason, the relationship between the target targets before and after switching is clearly displayed.

  Further, the display data generation unit of the radar apparatus according to the present invention is characterized in that the intermediate display data is sequentially displaced from the target target side to the hypothetical target target side and output.

  Further, the radar detection signal processing and display method according to the present invention is characterized in that the intermediate display data is sequentially displaced from the target target side to the hypothetical target target side in the step of generating intermediate display data and output.

  In these configurations, when the target target currently being tracked is switched to the hypothetical target target, the target target after switching (the target target being currently tracked) is changed from the display position of the target target before switching (the target target currently being tracked). The display position of the target target is sequentially shifted to the display position of the hypothetical target target) by the intermediate display data. For this reason, the position of the target target is output as a moving image on the display screen when the target is switched.

  The display data generating means of the radar apparatus according to the present invention is characterized in that the intermediate display data to be output is sequentially increased from the target target side to the hypothetical target target side.

  The radar detection signal processing and display method of the present invention is characterized in that the intermediate display data to be output is sequentially increased from the target target side to the hypothetical target target side in the step of generating intermediate display data. .

  In these configurations, when the display position of the target target is sequentially changed, the intermediate display data is output while increasing in order, so that the target target before switching (target target currently being tracked) The trajectory of the target target is displayed in a line shape that sequentially extends from the side to the switched target target (hypothetical target target) side.

  According to the present invention, even when a target target that has been tracked so far is switched to a hypothetical target target, the radar apparatus and the radar detection signal processing that allows the user to easily recognize the relationship between the target target before and after the switching. A display method can be provided.

  In addition, according to the present invention, when a target target that has been tracked so far is switched to a hypothetical target target, which target target is switched to the hypothetical target target can be displayed in a moving image. Accordingly, it is possible to provide a radar apparatus that makes it easy for the user to recognize the switching of the target target, and a radar detection signal processing and display method.

  Further, according to the present invention, when the target target is switched, it is possible to display the target target switching with a trajectory. As a result, it is possible to provide a radar apparatus that allows the user to more easily recognize the switching of the target target, and a radar detection signal processing and display method.

A radar apparatus according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram showing a schematic configuration of a radar apparatus according to the present embodiment.
As shown in FIG. 1, the radar apparatus according to the present embodiment receives a radar detection signal and outputs a video signal including a detection image by a transmission unit 1 that generates a transmission signal, a transmission / reception switch 2, an antenna 3, and a radar detection signal. A receiving unit 5, a signal processing unit 6 including a MHT processing unit for performing predetermined processing on the video signal, a display 7, and a synchronization signal generating unit 4 for providing a synchronization signal to each of these units. Further, the transmission unit 1 includes a high-voltage power supply 11, a modulator 12, a power amplifier 13, a reference signal generator / exciter 14, and the reception unit 5 includes an LNA 50, a mixer 51, an IF amplifier / detector / video amplifier 52, The signal processing unit 6 includes an A / D converter 61 and a data processor 62 that performs MHT processing.

  The synchronization signal generator 4 gives a transmission trigger pulse to the modulator 12. The modulator 12 outputs a pulse signal to the power amplifier 13 using the high voltage power supply 11 as a power supply in accordance with the given transmission trigger pulse. The power amplifier 13 amplifies the transmission signal and outputs it to the antenna 3 via the transmission / reception switch 2 composed of a circulator or the like. The antenna 3 receives a signal reflected from a target in a predetermined area, and guides the received signal to a low noise amplifier (LNA) 50 via the transmission / reception switch 2. The low noise amplifier (LNA) 50 amplifies the received signal and outputs it to the mixer 51. The mixer 51 mixes the frequency signal generated by the reference signal generator / exciter 14 and the received signal and outputs a received intermediate frequency signal. The IF amplifier / detector / video amplifier 52 performs amplification and detection of the received reception intermediate frequency signal, generates and amplifies a video signal as a radar detection signal, and outputs it to the signal processing unit 6 and the display 7. The A / D converter 61 converts the video signal (radar detection signal) into digital radar detection data and outputs it to the data processor 62. The data processor 62 captures and tracks a desired target (target target) by MHT processing, which will be described later, using the input radar detection data, and displays an echo trail image (display data) on the display 7 as necessary. ) Is output. Here, the data processor 62 performs MHT processing to capture and track a desired target target, and also capture and track at least one hypothetical target target corresponding to the target target. . Then, if the tracking quality of the target target currently being captured / tracked is degraded and the accuracy of the hypothetical target target has reached the predetermined standard, the target target is changed from the previous target to the hypothetical target target. Switch to output an echo image. At this time, intermediate display data is generated between the echo display position of the target target immediately before switching and the echo display position of the target target immediately after switching (the first hypothetical target target), and is output as a moving image. The user is made aware that the target target has been switched before and after switching.

Next, a specific radar detection data processing and display method will be described.
FIG. 2 is a block diagram showing the configuration of the signal processing unit 6, and FIG. 3 is a block diagram showing the configuration of the motion estimation unit 66.
As shown in FIG. 2, the signal processing unit 6 includes an A / D converter 61, a data processor 62, and an azimuth data generation unit 63, and the azimuth data generation unit 63 is connected to the antenna 3 and the azimuth sensor 102. Has been. The data processor 62 includes an echo detector 64, an echo selector 65, a motion estimator 66, and a display data generator 67. The motion estimator 66 is connected to the GPS receiver 101 and the direction sensor 102.

  The A / D converter 61 converts the video signal (radar detection signal) input from the receiving unit 5 into digital radar detection data and outputs the digital radar detection data to the echo detection unit 64. The azimuth data generation unit 63 adds the antenna angle data input from the antenna 3 and the bow direction data input from the azimuth sensor 102 and outputs the antenna azimuth data to the echo detection unit 64. The echo detector 64 detects (captures) an echo that can be regarded as a target from the antenna orientation data and the radar detection data, calculates representative position data of each target (echo), and calculates an echo selector 65 and a motion estimator 66. Output to. The echo sorting unit 65 selects only echo data (such as representative position data) corresponding to the target target currently being tracked, and outputs the selected echo data to the motion estimation unit 66. Here, the echo detector 64 and the echo selector 65 correspond to the “target capturing means” of the present invention.

  As illustrated in FIG. 3, the motion estimation unit 66 includes a normal target motion estimation unit 661 that performs tracking processing of a target target that is currently being tracked, a hypothesis target capture unit 662 that performs processing of capturing a hypothetical target target, and a hypothesis. When switching from a target target currently being tracked to a hypothetical target target, a hypothetical target motion estimation unit 663 that performs target target tracking processing, a normal target tracking quality evaluation unit 664 that evaluates tracking reliability of the target target, And a tracking correction unit 665 for performing the correction process. Further, the motion estimation unit 66 inputs the ship speed of the ship from the GPS receiver 101 and the bow direction of the ship from the direction sensor 102, and targets in the normal target motion estimation unit 661 and the hypothetical target motion estimation unit 663. Used for motion estimation. Here, the normal target motion estimation unit 661 and the hypothesis target motion estimation unit 663 correspond to the “target motion estimation unit” of the present invention, and the hypothesis target capture unit 662 corresponds to the “hypothesis target capture unit” of the present invention, The normal target tracking quality evaluation unit 664 corresponds to the “tracking quality evaluation unit” of the present invention, and the tracking correction unit 665 corresponds to the “target target switching unit” of the present invention.

  The normal target motion estimation unit 661 estimates the target target's momentum from the echo data of the target target currently being tracked input from the echo sorting unit 65 by using the αβ tracker or the Kalman filter described above. To track. At this time, the normal target motion estimation unit 661 stores the target data related to the estimated motion amount such as the estimated position in a normal target file in the memory area in the apparatus, and the hypothesis target capturing unit 662, the normal target tracking quality evaluation unit 664, and the display The data is output to the data generation unit 67.

The hypothesis target acquisition unit 662 detects (captures) a hypothesis target target corresponding to the target target currently being tracked based on the echo data input from the echo detection unit 64 and the target data from the normal target motion estimation unit 661. And output to the hypothesis target motion estimation unit 663. The hypothesis target motion estimation unit 663 estimates the amount of motion of the hypothesis target target from the hypothesis target target echo data input from the hypothesis target capture unit 662 using the αβ tracker and the Kalman filter described above, The target data related to the estimated momentum is output to the tracking correction unit 665.
Specifically, the hypothesis target is captured and tracked based on the flow shown in FIG.
FIG. 4 is a follow chart showing a hypothesis target target capturing / tracking method, and FIG. 5 is a diagram showing a concept of the hypothesis target target capturing method.
In the hypothesis target capturing unit 662, a NEAR gate including a region wider by a predetermined range than the prediction gate (region where the target target will exist in the next scan) in the normal target motion estimation unit 661 is set. The hypothesis target acquisition unit 662 selects a hypothesis target candidate target echo from the echoes present in the NEAR gate (S1). Next, the hypothesis target acquisition unit 662 obtains target data of a hypothesis target target echo currently being tracked from a hypothesis target file in a memory area in the apparatus, and among the selected hypothesis target candidate echoes, If there is something corresponding to the hypothesis target target echo being tracked, the hypothesis target motion estimation unit 663 continues tracking (S2 → S8).

  Here, if there is no hypothesis target target echo currently being tracked in the selected hypothesis target candidate target echo, the already selected echo data stored in the entry file in the memory area of the device is read and selected this time. The made hypothesis target candidate target echo is collated with the stored echo data (S2-> S3-> S4). If echo data corresponding to the selected hypothesis target candidate target echo is already stored in the entry file, the echo data of the entry file is updated (S4 → S5). Then, the hypothesis target capturing unit 662 updates the echo data of the entry file and counts up the number of updates, and determines that the hypothesis target target echo is captured when the number of updates exceeds a predetermined threshold. The echo data is output to the hypothetical target motion estimation unit 663. The hypothetical target motion estimation unit 663 stores the echo data of the hypothetical target echo as target data in the hypothesis target file and starts the tracking process of the hypothetical target (S6 → S7 → S8).

  On the other hand, if the selected hypothesis target candidate target echo does not correspond to the echo data already stored in the entry file, new echo data is stored (registered) in the entry file (S4 → S9).

  Further, the hypothesis target capturing unit 662 counts up the number of non-updates for the echo data stored in the entry file, and deletes this echo data when the number of non-updates exceeds a predetermined threshold ( S10 → S11 → S12).

  By repeating such a series of operations at a predetermined cycle (scan cycle), the selection of consecutive hypothesis target candidate targets and hypothesis target targets corresponding to the target target currently being tracked according to the time point. Capture / tracking, registering new hypothesis target candidates, and deleting unnecessary hypothesis target candidates. This makes it possible to capture and track only the necessary hypothetical target at the time of each scan. Further, by not capturing / tracking unless it is selected a predetermined number of times or more, it is possible to prevent noise such as clutter from being captured / tracked as a hypothetical target.

  In addition, hypothetical target targets that are captured and tracked in this way are generated one after another as the target target moves. For this reason, the hypothesis target motion estimation unit 663 reads the target data of each hypothesis target that is stored in the hypothesis target file memory at a predetermined period set in advance, and erases the target data that satisfies the erasure condition. As the erasure condition, for example, (1) the elapsed time from the start of tracking of the hypothetical target target is a predetermined time or more, or (2) the interval between the hypothetical target target and the target target is And (3) the condition that the echo of the hypothetical target object disappears and tracking becomes impossible can be adopted.

  Next, the tracking quality evaluation of the target target will be described.

  The normal target tracking quality evaluation unit 664 uses the target data of the target target output from the normal target motion estimation unit 661 to evaluate the tracking quality at a predetermined period. As the evaluation method, the content of each item shown below is digitized, scale conversion and weighted average processing are performed, and the tracking quality as a whole is calculated as a one-dimensional numerical value. Then, the normal target tracking quality evaluation unit 664 outputs a numerical value representing the tracking quality to the tracking correction unit 665.

(A) Tracking estimated speed change rate The estimated speed data is extracted from the target data of the target target, recorded at predetermined intervals, and the change rate is digitized. For example, if the rate of change in speed at the n-th scan is DV_RATE (n), the estimated speed at that time is V (n), and the estimated speed at the immediately preceding n-1 scan is V (n-1). In this case, the speed change rate (tracking estimated speed change rate) DV_RATE (n) is
DV_RATE (n) = ABS (V (n) −V (n−1) / V (n))
Can be calculated. This tracking estimated speed change rate is “0” if the estimated speed of the target target is constant, indicating that the tracking quality is good.
(B) Echo non-detection probability The probability that the echo corresponding to the target target does not exist in the prediction gate in a certain period is quantified. For example, the echo non-detection probability P when the number of times that no echo is detected within N scans is M is
P = M / N
Can be calculated. The echo non-detection probability P is “0” if the echo is always detected, indicating that the tracking quality is good. If the echo is detected or not detected, the numerical value increases. The higher the numerical value, the higher the tracking quality. Indicates a bad condition.
(C) Echo shape value change rate The shape of the echo is calculated from the input target target data, digitized according to the shape, and the change in the numeric value is digitized as the echo shape value change rate. As the echo shape value, for example, the ratio (Lr / Laz) of the echo distance direction length Lr and the azimuth direction length Laz as shown in FIG. 6 or data equal to or higher than the echo detection level as shown in FIG. And the ratio (Se / Sle) of the echo area Se to the rectangular area Sle that encloses the echo. If the echo shape value change rate is small, the tracking quality is good.

  6 and 7 are conceptual diagrams for explaining the echo shape value. FIG. 6 shows the concept of the echo distance direction length Lr and the azimuth direction length Laz. FIG. 7 shows the echo area Se and the rectangular area Sle. Represents the concept of

(D) Noise generation rate around the target target echo with respect to the hypothetical target number that needs to be tracked in the above NEAR gate, that is, the number T_VOL of the hypothetical target target stored in the hypothetical target file memory The number N of the hypothesis target once captured in the NEAR gate, that is, the ratio N_RATE of the echo number E_VOL that is temporarily stored in the entry file memory but is not stored in the hypothesis target file memory is quantified. This ratio (noise generation rate around the target target echo) N_RATE is
(N_RATE) = (E_VOL) / (T_VOL)
When the radar image is very clear, E_VOL and T_VOL match, so N_RATE is “1”, indicating that the tracking quality is good. On the other hand, when noise such as sea surface reflection or wind / snow reflection occurs, the noise may be temporarily captured as a hypothetical target. At that time, E_VOL is larger than T_VOL, and therefore N_RATE is larger than “1”, indicating that the tracking quality is poor.

Then, all the items (a) to (d) or necessary items are digitized and subjected to scale conversion and weighted average processing to calculate one total tracking quality evaluation value Qa.
This total tracking quality evaluation value Qa is obtained when the numerical value of each of the items (a) to (d) is Qn and the weighted weight value for each numerical value Qn is Wn.
Qa = ΣQn · Wn
Can be expressed as If the total tracking quality evaluation value Qa is small, the tracking state is good and indicates that the possibility that a tracking error has occurred is low. If the total tracking quality evaluation value Qa is large, the tracking state is bad and a tracking error occurs. This indicates a state where there is a high possibility that
Note that the weight value Wn can be arbitrarily set by the user, and may be set to an appropriate value according to the radar performance and usage conditions.
Next, a tracking correction method, that is, a method of switching a target target currently being tracked to a hypothetical target target will be described.
FIG. 8 is a flowchart showing a method of switching the tracking target from the target target currently being tracked to the hypothetical target target.
The tracking correction unit 665 compares the total tracking quality evaluation value Qa input from the normal target tracking quality evaluation unit 664 with a previously stored quality evaluation threshold value (S21 → S22). This quality evaluation threshold means that if the threshold is exceeded, the tracking quality is poor, and it becomes difficult to continuously capture and track the target object currently being tracked, and a tracking error is likely to occur. At this time, if the specific Qn is large in advance according to the use situation, an appropriate tracking quality evaluation threshold value can be obtained by performing a non-linear setting such as increasing the quality evaluation threshold value.
When the total tracking quality evaluation value Qa exceeds the quality evaluation threshold value, the tracking correction unit 665 determines the hypothetical target target corresponding to the target target currently being tracked from the target data input from the hypothetical target motion estimation unit 663. Whether the target data exists is identified (S23). Here, if there is a hypothetical target, the estimated speed, the echo non-detection probability, and the echo shape value change rate are calculated and stored for this hypothetical target, and are obtained by the normal target tracking quality evaluation unit 664. The target target estimated speed, the echo non-detection probability, and the echo shape value change rate are acquired, and a difference value is calculated between the hypothetical target target and the target target for each item. Then, each difference value is multiplied by a weight value to obtain a sum, and if this sum is within a predetermined threshold, the tracking correction unit 665 has the same hypothesized target target that is currently being tracked as the target target being tracked. (S24 → S25). Next, the tracking correction unit 665 overwrites and stores the target data of the hypothetical target target in the normal target file of the normal target motion estimation unit 661 and also stores the target data of the hypothetical target target stored in the hypothesis target file. Is initialized (erased) (S26 → S27). Then, the tracking correction unit 665 outputs the target data (corrected momentum) of the hypothetical target target to the display data generation unit 67 (S28).

Next, the display data generation unit will be described.
FIG. 9 is a block diagram illustrating a schematic configuration of the display data generation unit 67. The display data generation unit 67 includes a normal target display data generation unit 671, a corrected display data generation unit 672, and a display data synthesis unit 673.
The normal target display data generation unit 671 is based on the estimated momentum data that is output from the normal target motion estimation unit 661 of the motion estimation unit 66 and is the target data of the target target that is currently being tracked. Is output to the display data synthesis unit 673.
The corrected display data generation unit 672 generates display data of a hypothetical target target that switches from the target target currently being tracked when the corrected momentum data that is target data of the hypothetical target target is input from the tracking correction unit 665. To do. At the same time, the corrected display data generation unit 672 is positioned between the display data of the hypothetical target target and the display data of the target target based on the corrected momentum data and the estimated momentum data of the target target currently being tracked. Generate intermediate display data. Then, the corrected display data generation unit 672 outputs the generated hypothesis target target display data and intermediate display data to the display data synthesis unit 673.
Specifically, when the estimated speed of the target target is Va, the estimated position is Xa, the estimated speed of the hypothetical target target is Vb, and the estimated position is Xb, the target target and the hypothetical target target are estimated. A speed difference D_V and an estimated positional deviation amount D_R are calculated.
Then, the estimated speed difference D_V and the estimated position shift amount D_R are divided by the division number N corresponding to the number of intermediate display data, and the speed change amount dv (= (D_V) / N) and the position change amount dr (for each intermediate display data) = (D_R) / N).

By performing such calculation, the estimated speed MV and estimated position MX of the Mth intermediate display data from the display data of the target target are
MV = Va + M × dv
MX = Xa + M × dr
The intermediate display data calculated from these equations is output to the display data synthesis unit 673.

When the display data is input only from the normal target display data generation unit 671, that is, when the target target is captured and tracked without any problem, the display data synthesis unit 673 only displays the display data of the target target. Output. On the other hand, when the hypothetical target display data and the intermediate display data are input from the corrected display data generation unit 672, that is, the tracking quality of the target target decreases, and the hypothetical target target is detected from the target target currently being tracked. In the case of switching to the display data, the display data synthesis unit 673 outputs the display data of the hypothetical target target together with the display data of the normal target target, and further outputs the intermediate display data positioned between these display data. .
FIGS. 10A and 10B are diagrams showing the display state of the display. FIG. 10A shows a tracking state of a normal target target, FIG. 10B shows a state where a tracking error of the target target has occurred, and FIG. The initial state of switching to a hypothetical target is shown, and (d) shows a display state that clarifies this switching state. In addition, the white circle mark in the figure indicates the tracking target mark, the solid oval-shaped hatched substantially oval mark indicates the display data of the target, and the solid oval combined grid-hatched substantially oval mark is a fixed object. The mark display data (echo) is shown, and a substantially oval mark hatched with a solid diagonal line indicates intermediate display data.
As shown in FIG. 10A, if there is no problem in tracking of the target target, only display data indicating the tracking result of the target target is displayed on the display unit 7. When a tracking error of the target target occurs, an incorrect result is displayed such that the display data of the target target overlaps the display data of the fixed target as shown in FIG. When the tracking quality of the target target is reduced by using the configuration of the present embodiment so that such a state does not occur, the display data of the target target is the hypothetical target object as shown in FIG. The display is switched to the display data of the target and displayed together with the display data of the fixed target. At this time, since the display data of the target target and the display data of the hypothetical target target are separated from each other on the screen of the display unit 7, as shown in FIG. The intermediate display data is displayed on the screen of the display 7 so as to move sequentially to the display data of the hypothetical target. As a result, the switching of the target target is displayed as a moving image, and the user can easily recognize that the target target has been switched to the hypothetical target target, and which target target displayed on the display unit is the hypothetical target target. It can be easily recognized whether it has been switched to the mark. At this time, it is only necessary to know that the display of the intermediate display data shifts from the target target to the hypothetical target target.For example, by displaying and deleting the intermediate display data in order, the target display is sequentially switched from the target target to the hypothetical target target. There is a display method in which the position changes. In addition, by displaying intermediate display data in order and erasing all intermediate display data after a predetermined time after all intermediate display data is displayed, the hypothetical target object is derived from the trajectory of the intermediate display data, that is, the display data of the target target. You may use the method of displaying the transition to the display data of a mark with a locus | trajectory.

  By using the configuration and method as described above, even if the target target currently being tracked cannot be tracked, it is possible to switch to the hypothetical target target and continue tracking. By displaying intermediate display data indicating the switching of the target target sometimes, it is possible to configure a radar apparatus that allows the user to easily recognize the switching of the target target.

  In the above-described embodiment, the hypothesis target target is captured and tracked with respect to the target target currently being tracked. However, the hypothesis target target is further captured and tracked with respect to the hypothesis target target. In contrast, the above-described target target switching display process can be used.

1 is a block diagram showing a schematic configuration of a radar apparatus according to an embodiment of the present invention. The block diagram which shows schematic structure of the signal processing part 6 of the radar apparatus shown in FIG. The block diagram which shows schematic structure of the motion estimation part 66 of the signal processing part 6 shown in FIG. Follow chart showing how to capture and track hypothetical target Diagram showing the concept of a hypothetical target capture method Conceptual diagram for explaining echo shape values Conceptual diagram for explaining echo shape values Flow chart showing how to switch from a target target currently being tracked to a hypothetical target target The block diagram which shows schematic structure of the display data generation part 67 of the signal processing part 6 shown in FIG. Figure showing the display status on the display unit The block diagram which shows schematic structure of the signal processing part 6 provided with the function of ARPA Conceptual diagram showing the tracking method of αβ tracker

Explanation of symbols

1-transmission unit 11-high voltage power supply 12-modulator 13-power amplifier 14-reference signal generator / exciter 2-transmission / reception switch 3-antenna 4-synchronization signal generator 5-reception unit 50-LNA
51-mixer 52-IF amplifier / detector / video amplifier 6-signal processor 61-A / D converter 62-data processor 63-azimuth data generator 64-echo detector 65-echo selector 66-motion estimation Unit 661-normal target motion estimation unit 662-hypothesis target capture unit 663-hypothesis target motion estimation unit 664-normal target tracking quality evaluation unit 665-tracking correction unit 67-display data generation unit 671-normal target display data generation unit 672- Modified display data generator 673-Display data synthesizer 7-Display 101-GPS receiver 102-Direction sensor

Claims (8)

The movement of the target target and the movement of the hypothetical target target are obtained from the target target obtained from the radar detection signal and the detection image data of the hypothetical target target different from the target target and the speed and direction of the own device. Target motion estimation means to estimate,
The target target being currently displayed performs toggle its judgment to the hypothesis targets target object that is not currently displayed, and the target target switching means for switching the target target according to the determination result,
If the target target switching means switches the target target, the display data of the target target being currently displayed, when switching to the display data of the hypothesis targets target that is not currently displayed, the currently displayed Intermediate display data at the position indicated by the estimated position and estimated speed calculated based on the estimated position and estimated speed of the target target and the estimated position and estimated speed of the hypothetical target target that is not currently displayed. And a display data generating means for simultaneously outputting the intermediate display data and the display data of a hypothetical target target that is not currently displayed as a new target target . Using the detection image data obtained from the radar detection signal, the target target is captured, and the target other than the target target including the hypothetical target target existing in a predetermined area including the target target. Target capturing means for capturing
A hypothesis target target detecting means for comparing the estimated momentum of the target target and the estimated momentum of the target in the predetermined area, and detecting a hypothetical target target from the target in the predetermined area;
And a tracking quality evaluation means for evaluating the tracking quality of the target target using the estimated momentum of the target target,
The radar apparatus according to claim 1, wherein the target target switching unit determines to switch the target target to the hypothetical target target when the tracking quality of the target target does not conform to a predetermined standard. The display data generation unit displays the display data of the target target that is the current display target and the hypothetical target target that is not currently displayed and becomes a new target target when the target target is switched. together and outputs the data at the same time, the radar apparatus according to claim 1 or claim 2, outputted from the target target object side the intermediate display data by sequentially displacing to the hypothesis targets target object side. The display data generation means displays the display data of the target target that is the current display target and the hypothetical target target that is not currently displayed as a new target target when the target target is switched. Output the data at the same time , and generate the intermediate display data at a plurality of intermediate positions of the display data of the target target and the display data of the hypothetical target target, with respect to the generated plurality of intermediate display data The radar apparatus according to claim 1 or 2 , wherein the number of output data is sequentially increased from the target target side to the hypothetical target target side. Estimate the motion of the target target and the motion of the hypothetical target target from the target image obtained from the radar detection signal and the detected image data of the hypothetical target target different from the target target and the speed and direction of the device itself And steps to
The target target being currently displayed performs toggle its judgment to the hypothesis targets target object that is not currently displayed, and performing switching of the target target according to the determination result,
If the target target switching means switches the target target, the display data of the target target being currently displayed at the time of switching to the display data currently displayed no hypothesis targets target, switching of the front and rear Estimated position and estimated speed calculated based on the estimated position and estimated speed of the target target currently displayed between the coordinate positions of display data and the estimated position and estimated speed of a hypothetical target target not currently displayed Generating intermediate display data at a position represented by the following , and simultaneously outputting the intermediate display data and display data of a hypothetical target target that is not currently displayed as a new target target . Radar detection signal processing and display method characterized by the above. Using the detection image data obtained from the radar detection signal, the target target is captured, and a target other than the target target including the hypothetical target target existing in a predetermined area including the target target is captured. Step to capture,
Comparing the estimated momentum of the target target with the estimated momentum of the target in the predetermined area, and detecting a hypothetical target target from the target in the predetermined area;
Anda step of evaluating the tracking quality of the target target using the estimated momentum of the target target,
The step of switching the target target includes:
The radar detection signal processing and display method according to claim 5 , wherein when the tracking quality of the target target does not conform to a predetermined standard, it is determined to switch the target target to the hypothetical target target. The step of simultaneously outputting the intermediate display data and the display data of a hypothetical target target that is not currently displayed as a new target target is the target object that is currently displayed when the target target is switched. and display data preparation, not currently displayed as the new target target the hypothesis targets target both outputs display data at the same time, the intermediate display data from the target target object side to the hypothesis targets target object side 7. The radar detection signal processing and display method according to claim 5 or 6, wherein the signals are sequentially displaced. The step of simultaneously outputting the intermediate display data and the display data of a hypothetical target target that is not currently displayed as a new target target ,
At the time of switching the target target, simultaneously output the display data of the target target that is the current display target and the display data of the hypothetical target target that is not currently displayed as a new target target the intermediate display data, said generated at a plurality of intermediate positions between the display data of the target target display data of said hypothesis targets target, the number of output data for a plurality of intermediate display data the generated, the target The radar detection signal processing and display method according to claim 5, wherein the radar detection signal processing is sequentially increased from the target side to the hypothetical target target side.

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