JP3492403B2 - Automatic radar tracking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing apparatus for calculating output data based on a plurality of types of time-series detection data relating to the same object, and more particularly, to calculating output data. The present invention relates to an improvement in a selection method for selecting an optimal data combination from a plurality of types of time-series detection data for performing the above-described operations. 2. Description of the Related Art In a ship system such as an automatic radar tracking device, there are a plurality of sensors (for example, a gyro or an electromagnetic log) for detecting data relating to the speed of the ship, and by combining these input data, Processing data such as other ship speed data is created. The automatic radar tracking device calculates the true speed data of the target based on the own ship speed data and the relative speed data of the target detected from the radar image with respect to the own ship. However, for example, when trying to calculate own ship speed data (vector data) from gyro data (direction data) and log data (speed data), the gyro data is generally While log data is input every 25 ms, log data differs depending on the speed of the ship, but is generally input only once every 1 to 2 seconds. In this case, accurate data cannot be calculated and an error occurs. When the true speed of the target is obtained by using the own ship speed data calculated in this way, there is a possibility that an accurate true speed cannot be obtained and accurate tracking cannot be performed. An object of the present invention is to select an appropriate combination of a plurality of time-series detection data such as a gyro and logging data, by calculating the output data such as the ship speed data, calculation of the output data Eliminate errors
Another object of the present invention is to provide an automatic radar tracking device . [0008] The invention according to claim 1 of the present application provides own ship speed data based on log data and gyro data input asynchronously, respectively. In the automatic radar tracking device to calculate, a gyro data table and a log data table for sequentially storing the log data and the gyro data together with their input time data, and as the data for calculating the own ship speed data when calculating the own ship speed data. Data selecting means for selecting the latest log data from the log data table and selecting the gyro data whose input time is closest to the log data from the gyro data table. FIG. 1 is a conceptual diagram for explaining the present invention. A plurality of time-series detection data are detected for one target, and are input asynchronously. These data are sequentially (time-sequentially) stored in the storage means. When storing this time-series detection data, the input time data of the data is stored in association with the data. When the timing for calculating the output data comes (for example, this timing is instructed by the output data calculation unit), the data selection means selects the corresponding time-series detection data as output data calculation data based on the input time data, and outputs Pass it to the data calculation unit. The output data calculation unit calculates and outputs output data based on the time series detection data. As a method of selecting output data calculation data, the latest data is selected from one piece of time-series detection data, and data closest in time to this data is selected from the other time-series detection data. select. This allows
The calculation output of the output data can be performed based on the substantially simultaneous data, and the output data can be calculated with high accuracy. In the invention of claim 3 of this application, log data is used as one time-series detection data, and gyro data is input as time-series detection data every other time and asynchronously, and among these time-series detection data, From the above, the optimum combination is obtained based on the above-mentioned method, and the own ship speed data is calculated. Gyro data is input approximately every 25 ms, whereas log data is input only approximately once every 1-2 seconds. For this reason, when calculating output data, highly accurate own ship speed data can be calculated by selecting a combination of data at almost the same input time by the above method. Further, in the automatic radar tracking apparatus according to the fourth aspect, log data and gyro data are inputted asynchronously, input time data is added to them, and they are stored in the gyro data table and the log data table. When calculating own ship speed data, the latest log data is selected from the log data table. This is because the input frequency of the log data table is lower than that of the gyro data table as described above. Further, gyro data whose input time is closest to the log data is selected from the gyro data table. As a result, the latest combination data having the closest input time can be extracted, and based on this, accurate ship speed data can be calculated, and the target can be tracked accurately. FIG. 2 is a block diagram of an automatic radar tracking apparatus according to an embodiment of the present invention. This automatic radar tracking device is a device mounted on a ship, calculates own ship speed data based on azimuth data detected by the gyro 20 and speed data detected by the electromagnetic log 21, and calculates the own ship speed data. This is a device that calculates and displays true speed data of the target by subtracting from the relative movement speed data of the target detected by the radar 23. These azimuth data and speed data correspond to a plurality of types of time-series detection data relating to the same object (own ship) of the present invention, and own ship speed data corresponds to output data of the present invention. The gyro 20, the electromagnetic log 21, and the radar 23 are other devices installed outside the automatic radar tracking device, and are connected to the device via a data cable. In the automatic radar tracking device, the CPU 10, the memory 11, the timer 12, the interfaces 13, 14, 1
5 and an image memory (VRAM) 16 are connected via a bus. The interface 13 includes the gyro 2
0 is connected. The electromagnetic log 21 is connected to the interface 14 via an A / D converter 24.
This is because the gyro 20 outputs digitized azimuth data, whereas the electromagnetic log 21 outputs a voltage value corresponding to the ship speed. This voltage value is converted into digital data by the A / D converter 24. That's why. A radar 23 is connected to the interface 15 via an A / D converter 25. The radar 23 outputs a radial scan image, and the A / D converter 25 converts the image into digital image data in a matrix and buffers the digital image data in a memory built in the interface 15. CPU10
Periodically reads the digital image data in a matrix form from the interface 15 and writes it in the image memory 16. On the other hand, a display device 30 is connected to the image memory 16. The display device 30 includes a color CRT,
The contents stored in the image memory 16 are read for each frame and displayed on a color CRT. The display contents are as shown in FIG. FIG. 3 is a view showing a gyro data table, a log data table and a target coordinate table set in the memory. The gyro data table contains gyro data (direction data) DDD (degrees) input from the gyro 20. MM (minutes) is the input time data T
are sequentially stored together with n. The input time data Tn is a 16-bit value counted up every 10 ms, and is not data representing an absolute time. However, the relative time relationship between the input times of the gyro data and the log data can be known from this data. it can. This gyro data is about 25
Input every ms. On the other hand, log data (speed data) N input from the electromagnetic log 21 is stored in the log data table.
N (knot). XX are sequentially stored together with the input time data Tn. This log data is input approximately every 1 to 2 seconds. Therefore, these data are inputted at asynchronous intervals as shown in FIG. These tables are sequentially written each time data is input, and are all cleared when the own ship speed data calculation process (FIG. 5B) described later is executed. On the other hand, the target coordinate table stores coordinate values of the target detected by the radar 23 at predetermined times. The coordinates are coordinate values in a relative coordinate system centered on the own ship position, and the coordinate values are calculated based on digital image data in a matrix read out from the interface 15. FIGS. 5 and 6 are flowcharts showing a partial operation of the CPU 10. FIG. 5A shows a gyro data storage process and a log data storage process, and FIG. 5B shows an own ship speed data calculation process. Also,
FIG. 6A shows a radar image capturing process, and FIG. 6B shows a target speed calculating process. FIG. 4 is a diagram showing an input interval between gyro data and log data. The operation shown in FIG.
(Gyro data storage processing) and interface 14
(Log data storage processing) is executed at appropriate intervals. First, it is determined whether or not data exists in the buffer of the corresponding interface (n1). If there is no data, the operation ends. If there is data, the data is fetched (n2), and the time at that time is set to timer 1
2 (n3). The time data is added to the data (gyro data or log data), and writing is performed in the corresponding one of the gyro data table and log data table (n4). FIG. 2B is a flowchart showing the own ship speed data calculation operation. The own ship speed data is a process of obtaining a current speed vector (own ship speed data) of the own ship based on the azimuth data and the speed data, and adding it to a past wake to create new wake data. This operation depends on the amount of tasks of the CPU 10, but approximately once every two to three seconds.
Executed multiple times. First, the latest log data is searched from the log data table (n10). The reason why the log data is searched first is to search for the corresponding gyro data using the latest log data because the log data has a lower data input frequency than the gyro data. When the latest log data is searched, the input time is read, and the gyro data input at the time closest to the time is searched from the gyro data table (n11). In the example of FIG. 4, if the own ship speed data calculation operation is performed at time T, the log data selected at n10 is L2 data, and at n11, the log data is selected corresponding to this log data. Is G4 data. The wake data is calculated based on these data (n12). As described above, by selecting the data whose input times are close to each other, it becomes possible to calculate the own ship speed data with high accuracy.
This own ship speed data is written into an image memory (VRAM) 16 for display as numerical data of the direction and speed (n
13). The writing to the image memory 16 may be performed simultaneously with other display contents (speed data of the target, etc.). FIG. 6A shows a radar image capturing process. This operation is performed every predetermined time when the radar image is updated. First, a matrix-like radar image is fetched from the interface 15 (n20), and this data is written into the image memory (VRAM) 16 (n21). A target is detected from this data and the previously acquired data (n2
2) The coordinates of the target are calculated and written in the target table (n23). FIG. 2B shows a target speed calculation process. First, the coordinates of the target are read out in time series from the target coordinate table, and relative speed data (azimuth, speed) of the target is calculated based on these coordinate values and the time (n30). Next, it is determined whether the display mode of the display device 30 is the relative speed display mode or the true speed display mode (n31). here,
The relative speed display mode is a mode for displaying the relative speed data of the target with respect to the own ship, and the true speed is a mode for displaying the true speed with respect to the stationary coordinates of the target. In the case of the relative speed mode, since the relative speed data directly obtained from the coordinate values in n30 may be used as it is, the image displayed by numerical values (azimuth, speed) and arrows is edited (n34). Write to the memory (n35). The image data written in this way is displayed as shown in FIG. On the other hand, in the case of the true speed display mode, it is necessary to calculate the target true speed data based on the target relative speed data and the own ship speed data. Therefore, first, the own ship speed data is taken in (n32), and then, the true ship speed data (vector) is calculated by subtracting the own ship speed data (vector) from the relative speed data (vector) of the target. . The true speed data of each target obtained in this way is edited with numerical values (azimuth and speed) and an image displayed by an arrow (n34), and written into the image memory (n35). The image data thus written is displayed as shown in FIG. According to the above operation, the own ship speed data is calculated based on the gyro data and the log data which are observed almost at the same time. Calculation becomes possible. Furthermore, since the true speed of the target is calculated based on this,
An accurate true speed of the target can be calculated, and tracking accuracy of the target is improved. In this embodiment, an automatic radar tracking device is described. The target time series detection data is gyro data and log data, and the output data is own ship speed data. However, the present invention is limited to this example. For example, in a case where the present invention is applied to another ship-mounted device, in addition to gyro data and log data, GPS data and positioning data by Loran may be used. As described above, according to the present invention, even if a plurality of types of time-series detection data are input asynchronously, the corresponding data combination is selected to calculate the output data. It is possible to calculate good output data. In the automatic radar tracking apparatus according to the present invention, the own ship speed data is calculated by combining the latest log data with the gyro data whose input time is closest to the latest log data. Data can be calculated, and tracking of the target can be performed accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining the concept of the present invention. FIG. 2 is a block diagram of an automatic radar tracking device according to an embodiment of the present invention. FIG. 3 is a gyro of the automatic radar tracking device. FIG. 4 is a diagram showing a data table, a log data table, and a target coordinate table. FIG. 4 is a diagram illustrating input timing of gyro data and log data input to the automatic radar tracking device. 6 is a flowchart showing the operation of the control unit of the automatic radar tracking device. FIG. 7 is a diagram showing a display example of the automatic radar tracking device.

Claims (1)

(57) [Claims] [Claim 1] Log data input asynchronously
And own ship speed data based on gyro data
In the automatic radar tracking device, the log data and the gyro data
Gyro data table to store sequentially with time data
And a log data table for calculating the own ship speed data.
As data, the latest log from the log data table
Select the data and enter the log data
The gyro data table, which is close to the time,
Automatic radar tracking apparatus characterized by comprising a data selection means for selecting from.