Data Processing Unit

Abstract

To provide a data processing device that can shorten a processing delay in an RDF system.SOLUTION: A data processing device 22, which estimates a position of an aircraft serving as a transmission source of an aviation radio on the basis of an IP packet to be transmitted from a reception device 11 receiving the aviation radio of a prescribed frequency and including azimuth information indicative of an arrival direction of the aviation radio, is configured to set a timer having a collection period of the azimuth information defined for each frequency to start collecting the azimuth information; check a collection situation of the azimuth information on each frequency in a shorter cycle than the timer; group pieces of the azimuth information on frequencies having collections of the specified number completed; and perform grouping processing of grouping the pieces of the azimuth information collected so far, as for the frequencies in which the timer expires prior to the completion of the collections of the specified number, and position estimation processing of estimating a position of the aircraft conducting the aviation radio using the frequency on the basis of azimuth information grouped for each frequency by the grouping processing.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a data processing device that estimates the position of an aircraft that is the source of aviation radio signals. [Background technology]

[0002] Conventionally, RDF (Radio Direction Finder) systems have been used in air traffic control systems, etc. Figure 1 shows an overview of RDF systems deployed nationwide. Figure 2 shows an example of the configuration of an RDF system.

[0003] 1 and 2, the RDF system has a plurality of receiving stations 10 and a plurality of server stations 20, and these bases are connected by a wide-area communication network. The receiving station 10 has a receiving device 11 capable of receiving aircraft aviation radio signals at a plurality of frequencies, and a network device 12 for communicating with other stations via the communication network. The server station 20 has a network device 21 for communicating with other stations via the communication network, a data processing device 22 which is a computer that processes data transmitted from the receiving station 10, and an external storage device 23 for storing various data related to processing in the data processing device 22.

[0004] The receiving stations 10 are installed at bases throughout Japan. The receiving device 11 of each receiving station 10 detects voice communications by aircraft control, estimates the radio arrival direction, converts the estimated radio arrival direction into IP packets, and transmits them to the server station 20. The frequencies used for voice communications differ for each area formed by dividing the country into sectors, as shown in Tables 1 and 2 below. The sectors of the air traffic control area are set, for example, in a manner as shown in FIG. 3.

[0005] [Table 1]

[0006] [Table 2]

[0007] The data processing device 22 in the server station 20 extracts direction information indicating the radio arrival direction from the IP packets sent from the receiving stations 10 in various locations, and estimates the position of the aircraft using this direction information. The aircraft position information estimated by the data processing device 22 is visualized and displayed on a monitor or the like, and is used to support the situational awareness of the controller.

[0008] The following are examples of conventional technologies in the technical field of the present invention. For example, Patent Document 1 discloses an invention in which a second wireless station acquires propagation channel information calculated by a first wireless station to be positioned from a feedback frame of propagation channel information defined in wireless LANs after the IEEE802.11n transition, and estimates the position of the first wireless station based on the propagation channel information. For example, Patent Document 2 discloses an invention in which an aircraft is equipped with a communication device connectable to a packet switching line and a constant connection line, and current position data is normally transmitted to a ground station using the packet switching line, and when the aircraft reaches a range corresponding to the purpose, etc., the packet switching line is switched to the constant connection line to transmit the current position data to the ground station. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2021-100169 A [Patent Document 2] JP 2012-70260 A Summary of the Invention [Problem to be solved by the invention]

[0010] The problem with the RDF system is that there are multiple delay elements in the system as a whole, such as the following delay elements shown in Figure 4. (t1) Sampling time required for the receiver to detect voice and estimate the direction of arrival (t2) Transmission delay of IP packets containing direction information delivered from a receiving device in a wide area network (t3) Processing delay required to calculate the aircraft's position using the collected direction information

[0011] If it takes 100 milliseconds for (t1), 100 milliseconds for (t2), and 50 milliseconds for (t3), it will take at least 250 milliseconds to calculate the aircraft's position. In this case, if the pilot of the aircraft speaks and a ground controller listens to the voice and recognizes and indicates the aircraft's position, if there is an additional delay on top of the 250 milliseconds, the synchronization between the voice and the position display will be delayed by that amount. This can lead to misidentification and incorrect instructions, and may instead cause confusion in the RDF system that is supposed to support air traffic control.

[0012] However, although the above-mentioned delay elements (t1) to (t3) are caused by hardware, they are necessary delay elements to satisfy performance, and therefore it is difficult to solve them. The above-mentioned +α delay includes the following delay elements in the data processing device: (t4) Time to collect the necessary amount of direction information for position calculation (t5) Time required to group the collected direction information (grouping processing time)

[0013] The present invention has been made in consideration of the above-mentioned conventional circumstances, and has an object to provide a data processing device capable of reducing the processing delay of an RDF system. [Means for solving the problem]

[0014] In order to achieve the above object, a data processing device according to one aspect of the present invention is configured as follows. In other words, the data processing device of the present invention is a data processing device that estimates the position of an aircraft that is the source of an aviation radio signal based on an IP packet containing orientation information indicating the direction of arrival of the aviation radio signal, which is transmitted from a receiving device that has received aviation radio signals of a specified frequency. The data processing device starts the collection of orientation information by setting a timer that determines the collection period of orientation information for each frequency, checks the collection status of orientation information for each frequency at a period shorter than the timer, groups the orientation information for frequencies for which the specified number of pieces of information have been collected, and for frequencies for which the timer expires before the specified number of pieces of information have been collected, performs a grouping process that groups the orientation information collected up to that point, and a position estimation process that estimates the position of an aircraft transmitting aviation radio signals using that frequency based on the orientation information grouped by frequency by the grouping process.

[0015] Here, the data processing device according to the present invention can be configured so that at least one of the time length and the specified number of the timer in the grouping process can be changed.

[0016] Furthermore, the data processing device according to the present invention can be configured to perform grouping processing using a table in which aviation radio frequencies defined for each sector are set as frequencies that can be received by each receiving device. Effect of the Invention

[0017] According to the present invention, it is possible to provide a data processing device capable of reducing the processing delay of an RDF system. [Brief description of the drawings]

[0018] [Figure 1] This is a diagram showing an overview of the RDF systems deployed nationwide. [Diagram 2] FIG. 1 illustrates an example of the configuration of an RDF system. [Diagram 3] FIG. 2 illustrates an example of sectors of an air traffic control area. [Figure 4] FIG. 1 is a diagram showing where delay elements occur in an RDF system. [Diagram 5]11 is a diagram showing an example of an IP packet including direction information transmitted by a receiving device. FIG. [Figure 6] FIG. 2 is a diagram showing an overall processing flow in a data processing device. [Figure 7] FIG. 11 is a diagram showing the timing of collecting azimuth information. [Figure 8] FIG. 13 is a diagram showing an example of a receiving station table that is read at the time of startup. [Figure 9] FIG. 13 is a diagram illustrating an example of a buffer table generated from the receiving station table. [Figure 10] FIG. 11 is a diagram showing a processing flow when the data processing device receives an IP packet including direction information from a receiving device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of the present invention will be described with reference to the drawings. The schematic configuration of the RDF system is as shown in Figure 2. The RDF system of this example has about 100 receiving stations 10 located throughout the country, and two server stations 20, and these bases are connected by a wide-area communication network.

[0020] The receiving station 10 is equipped with a receiving device 11 that can simultaneously receive eight VHF aviation radio waves with an antenna and can process the signals of the eight aviation radio waves input simultaneously. Since the receiving device 11 can be set to receive eight frequencies, when it is placed in a sector (see, for example, Table 1 and Table 2), it can receive up to eight frequencies of VHF aviation radio signals used within the sector of the reception coverage centered on that position. The receiving device 11 is connected via Ethernet to a network device 12 (for example, network equipment such as a router or switch) that serves as an entrance / exit to the wide area network.

[0021] The server station 20 includes a data processing device 22, which is a computer device. The data processing device 22 extracts direction information from IP packets sent from the receiving stations 10 in various locations, and estimates the position of the aircraft using this direction information. The data processing device 22 is connected via Ethernet to a network device 21 (e.g., network equipment such as a router or switch) that serves as an entrance / exit to the wide area network. The data processing device 22 includes an external storage device 23 that stores the direction information collected from the receiving stations 10 in various locations, the calculated position information of the aircraft, and operation parameters related to the calculation process.

[0022] The receiving device 11 receives VHF aviation radio (voice radio) signals from aircraft using an antenna, performs voice sampling and estimates the direction of radio arrival using a well-known method, converts the results into IP packet data, and transmits them to the server station 20 via the network device 12 and the wide area network.

[0023] 5 shows an example of an IP packet transmitted by the receiving device 11. The IP packet transmitted by the receiving device 11 stores data such as the receiving station number, receiving frequency, direction information, receiving level, direction accuracy, ..., radio reception time, packet transmission time, etc. Data for eight waves that the receiving device 11 can process simultaneously can be stored for the receiving frequency, direction information, receiving level, direction accuracy, ..., and radio reception time.

[0024] The data processing device 22 performs a predetermined process using the IP packets collected from the receiving devices 11 in various locations via the network device 21, in the procedure shown in Fig. 6. That is, the data processing device 22 first extracts direction information from the collected packets, and performs a process of grouping the information by frequency used in each sector shown in Table 1 and Table 2 (hereinafter referred to as "grouping"). Next, the data processing device 22 performs a process of calculating the position of the aircraft based on the grouped direction information data. The position of the aircraft is calculated, for example, by inputting the grouped direction information data into a logic circuit of an FPGA (Field Programmable Gate Array) mounted on a board connected by PCI-Express inside the device. The data processing device 22 transmits the calculated aircraft position data in an IP packet, so that the device (destination 30) receiving the data can display the aircraft position.

[0025] Next, a method for reducing the additional delay time, which was cited as a problem in the conventional RDF system, will be described with reference to FIG. [Method 1] How to reduce the time (t4) required to collect direction information For example, a method is conceivable in which the data processing device 22 provides a section of X milliseconds, which is a certain fixed time, during which direction information is extracted from IP packets received from the receiving station 10 and handed over to the grouping process. In this case, since the timer X is uniformly fixed, if collection of the direction information for the specified number of groupings (e.g., "4") is completed at a millisecond before the timer X expires, it is necessary to wait for the remaining (Xa) milliseconds until the timer X expires. Also, in the next X millisecond section, if collection of the direction information for the specified number of groupings is completed at b milliseconds, it is necessary to wait for the remaining (Xb) milliseconds until the timer X expires.

[0026] A more detailed description will be given with reference to FIG. 7(A). In FIG. 7, packets transmitted from each receiving station are represented in the order of reception, such as "receiving station 1 packet" and "receiving station 2 packet". Also, the direction information extracted from the packets is represented as "direction 1" and "direction 2". Note that "direction n" is direction information indicating the radio arrival direction of the nth frequency. In FIG. 7(A), the data processing device 22 waits for the remaining (Xa) milliseconds until the timer X expires, and then performs grouping of "direction 2" and grouping of "direction 3". As described above, the method described above has a large delay because it is necessary to wait even after the collection of the direction information is completed.

[0027] Therefore, the time required for the data processing device 22 to collect azimuth information is reduced by the following method. (1) A timer X is provided that determines the collection period of azimuth information for each frequency. (2) A prescribed number (e.g., "4") is set that determines the amount of azimuth information to be collected for each frequency. (3) Timer X is started for each frequency upon receipt of the first direction information. (4) The collection status of azimuth information for each frequency is checked at a cycle Y that is sufficiently shorter than the timer X, and the azimuth information that has reached a prescribed number is handed over to the grouping process. (5) If the timer X for each frequency times out before the number of collected pieces of azimuth information reaches a prescribed number, the azimuth information collected up to that point is handed over to the grouping process.

[0028] A more detailed description will be given with reference to Fig. 7(B). In Fig. 7(B), since "orientation 1", "orientation 2", and "orientation 3" are extracted from the "receiving station 1 packet", the data processing device 22 starts the timers X for "orientation 1", "orientation 2", and "orientation 3" at that time. Furthermore, since "orientation 4" is newly extracted from the "receiving station 2 packet", the data processing device 22 starts the timer X for "orientation 4" at that time. Similarly, since "orientation 5" is newly extracted from the "receiving station 3 packet", the data processing device 22 starts the timer X for "orientation 5" at that time. After that, since "orientation 2" and "orientation 3" reach the specified number of groupings (=4) at the time of the "receiving station 4 packet", grouping of "orientation 2" and grouping of "orientation 3" are performed. Furthermore, since "orientation 1" reaches the specified number of groupings at the time of the "receiving station 6 packet", grouping of "orientation 1" is performed. On the other hand, since the timer X for each frequency timed out before the number of "direction 4" data collected reached the specified number, the three "direction 4" data collected up to that point were grouped.

[0029] Thus, in [Method 1], the data processing device 22 sets a timer that determines the collection period of the direction information for each frequency, starts collecting the direction information, checks the collection status of the direction information for each frequency at a period shorter than the timer, groups the direction information of the frequency for which the specified number of collections have been completed, and for the frequency for which the timer expires before the specified number of collections have been completed, performs a grouping process to group the direction information collected up to that point, and performs a position estimation process to estimate the position of the aircraft that uses the frequency for aviation radio based on the direction information grouped for each frequency. As a result, for example, in the method of FIG. 7(A), only the grouping process of "direction 2" and "direction 3" is performed within a period of X milliseconds, whereas in the method of FIG. 7(B), it is possible to perform the grouping process of "direction 1", "direction 2", "direction 3", and "direction 4". Furthermore, it is possible to perform the grouping process for "direction 2" and "direction 3" at an earlier timing than in the method of FIG. 7(A).

[0030] For example, if the number of collected orientation information items is insufficient for the accuracy of aircraft position calculation, the timer time that determines the orientation information collection period can be extended and / or the specified number of orientation information items required for grouping can be increased. In this way, by extending the timer time or increasing the specified number of orientation information items, more orientation information items can be collected and grouped, making it possible to switch to an operation that prioritizes the accuracy of position calculation. Also, if the calculation speed is more important than the accuracy of aircraft position calculation, the timer time can be shortened and / or the specified number of orientation information items can be reduced, on the contrary to the above. This allows the collection of orientation information to be completed and grouped in a shorter time, making it possible to switch to an operation that prioritizes the speed of position calculation.

[0031] [Method 2] How to reduce the grouping processing time (t5) for consolidating directional information As described above, the receiving device 11 can receive aviation radio signals of up to eight frequencies. For example, if the receiving device 11 of the receiving station 10 installed near sector F08 (East of Southern Kyushu) in Table 2 is within the coverage area of ​​sectors F01, F02, F03, F04, F06, F07, the receiving device 11 can receive aviation radio signals of the frequencies of the above eight sectors by setting the main VHF frequencies of these sectors (F01 to F08) as the receiving frequencies in the receiving device 11.

[0032] With this setting, when the receiving device 11 receives an aviation radio signal with the main VHF frequency of 132.5 MHz from F01, the frequency information of 132.5 MHz and its direction information are transmitted to the data processing device 22. Here, a method in which the data processing device 22 can determine the area using 132.5 MHz is to have the frequency tables shown in (Table 1) and (Table 2) in a table, search sequentially starting from the frequency of the first sector S01, and determine the sector with a matching frequency as the area using 132.5 MHz.

[0033] However, in the above method, the data processing device 22 needs to search all 49 sectors in order at the maximum. Also, when the receiver 11 receives up to 8 frequencies simultaneously, an IP packet containing frequency information and direction information for 8 waves is transmitted to the data processing device 22, so even in the case of only VHF frequencies, the data processing device 22 needs to search in a loop process of up to 8 x 49 x 3 (primary / secondary / emergency) every time it receives an IP packet. Furthermore, in Table 1 and Table 2, the 133.3 MHz frequency is used in two sectors, sector S01 and sector F08, but there are frequencies used in two or more sectors like this, so it is not possible to simply determine in which sector the frequency was used by just one loop process, which has a large impact on the processing time.

[0034] Therefore, the grouping process time for grouping the direction information is reduced by the following method. (1) In the data processing device 22, the location where each receiving device 11 is installed is associated with the frequencies of all eight waves that the receiving device 11 can receive and the collection group numbers for those frequencies, and this is prepared in a JSON format file (hereinafter referred to as the "receiving station table") as shown in FIG. 8. (2) When the data processor 22 is started, the receiving station table is read and expanded in memory, which acts as a hash table. (3) From the receiving station table expanded in the memory, a hash table (hereinafter referred to as a "buffer table") is created with a set of frequency and collection group number as a key and the address of the collection buffer for the azimuth information related to the key as a value. An example of the buffer table is shown in Figure 9. (4) When an IP packet is received from the receiving device 22, the receiving station number and each frequency included in the IP packet are checked against the receiving station table (FIG. 8) to extract the frequency and its group. (5) The extracted frequency and group pair is used as a search key to refer to the buffer table (Figure 9) to identify a collection buffer, and the azimuth information, etc. required for calculating the aircraft position is buffered in the collection buffer.

[0035] Fig. 10 shows the flow of the processing related to (4) and (5) above. That is, the data processing device 22 that receives the IP packet from the receiving device 11 first extracts a set of frequency and collection group number that will be a search key for the buffer table based on the receiving station number and each frequency included in the IP packet (steps S1 to S4). Next, the data processing device 22 refers to the buffer table using the extracted set of frequency and collection group number as a search key, extracts (the address of) the collection buffer that will be the storage destination for the azimuth information (step S5), and buffers the information required for calculating the aircraft's position in the collection buffer (step S6). The above processing is repeated for a maximum of eight waves of data included in the IP packet.

[0036] Thus, in [Method 2], the data processing device 22 is configured to perform grouping processing using a receiving station table in which the frequencies of aviation radio signals used in a certain sector are set as frequencies that can be received by each receiving device 11. This allows the data processing device 22 to perform grouping (buffering) of direction information with only a maximum of about eight loops each time an IP packet is received. As a result, it becomes possible to quickly calculate the positions of multiple aircraft.

[0037] In the above explanation, both [Method 1] and [Method 2] are implemented by the data processing device 22, but even if only one of these is implemented by the data processing device 22, the processing delay of the RDF system can be reduced.

[0038] Although the embodiments of the present invention have been described above, the above embodiments are merely illustrative and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and various modifications such as omissions and substitutions can be made without departing from the gist of the present invention. These embodiments and modifications are included in the scope and gist of the invention described in this specification, etc., and are included in the scope of the invention described in the claims and their equivalents.

[0039] Furthermore, the present invention can be provided not only as devices such as those described above or as a system composed of these devices, but also as methods executed by these devices, programs for causing a processor to realize the functions of these devices, and storage media for storing such programs in a computer-readable format. [Industrial Applicability]

[0040] The present invention can be used in a data processing device that estimates the position of an aircraft that is the source of aviation radio signals. [Explanation of symbols]

[0041] 10: Receiving station, 11: Receiving device, 12: Network device, 20: Server station, 21: Network device, 22: Data processing device, 23: External storage device

Claims

1. 1. A data processing device that estimates a position of an aircraft that is a source of an aviation radio signal based on an IP packet including azimuth information indicating a direction from which the aviation radio signal is arriving, the IP packet being transmitted from a receiving device that has received the aviation radio signal at a predetermined frequency, the data processing device comprising: A grouping process is performed in which a timer is set for each frequency, which determines the collection period of the azimuth information, and the collection status of the azimuth information of each frequency is checked at a period shorter than the timer, and the azimuth information of the frequency for which the specified number of collections have been completed is grouped, and for the frequency for which the timer expires before the specified number of collections have been completed, the azimuth information collected up to that point is grouped; and performing a position estimation process for estimating the position of an aircraft communicating with aviation radio using the frequency based on the direction information grouped for each frequency by the grouping process.

2. 2. The data processing device according to claim 1, 2. A data processing apparatus comprising: a processor for processing a plurality of groups of data; a timer for controlling a time period of the timer;

3. 3. The data processing device according to claim 1, 2. A data processing device comprising: a data processing unit for performing said grouping process using a table in which aviation radio frequencies defined for each sector are set as frequencies that each receiving device can receive.

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