JP5570964B2 - Ground equipment - Google Patents

Description

  Embodiments described herein relate generally to a ground device that receives and processes data transmitted from an aircraft.

  In order to ensure flight safety of an aircraft, the aircraft is monitored using a radar such as an SSR device (mode S secondary monitoring radar device) that transmits and receives an inquiry signal and a response signal. In addition, in order to prevent a collision between aircrafts, broadcast-type automatic dependent surveillance (ADS-B) that exchanges position information between aircrafts is also used. In addition, a broadcast information service-broadcast (TIS-B) that transmits aircraft flight information collected on the ground by the ground device to the aircraft is also used.

  By using ADS-B or TIS-B, the absolute position of the aircraft can be known. However, a conventional SSR device or the like can only know the relative distance from the aircraft to the device itself. Therefore, it is necessary to accurately grasp the position of the own device in order to specify the absolute position of the aircraft. For setting the position of the own apparatus on the ground apparatus, a position input by an operator or a position specified using GPS (Global Positioning System) is used.

JP 2004-170114 A

Michael C. Stevens “Secondary Surveillance Radar” 1988, ISBN 0-89006-292-7.

  However, when an input operation by an operator is used, there is a possibility that an accurate position cannot be set due to an input error or the like. In addition, when using GPS, it is necessary to add a GPS antenna, a receiver, and the like to the ground device.

  Therefore, the present invention provides a ground device that accurately identifies the position of its own device with a simple configuration from position information included in a signal transmitted by an aircraft.

  The ground device according to the embodiment of the present invention includes a distance specifying unit and a position specifying unit. The distance specifying means is a distance from the first transmission position that is the position of the aircraft that transmitted the first signal to the ground device, and a second position that is the position of the aircraft that transmitted the second signal after moving from the first transmission position. A distance from the transmission position to the ground device is obtained. When a plurality of distances between the aircraft and the ground device are determined by the distance specifying unit, the position specifying unit specifies the position of the ground device using the determined distances.

It is a block diagram explaining the structure of the ground apparatus which concerns on embodiment. It is a figure explaining the received signal from the aircraft utilized with the ground apparatus of FIG. It is a figure explaining the positional relationship of the aircraft in the time different from the ground apparatus of FIG. It is a figure explaining the positional relationship of two different machines in time different from the ground apparatus of FIG. It is a figure explaining the identification method of the position of a ground apparatus.

  Below, the ground apparatus which concerns on embodiment is demonstrated using drawing. The ground device 1 according to the embodiment is a device that is installed on the ground, receives and processes a signal transmitted from an aircraft transponder, and uses it for air traffic control. The signal used by the ground device 1 for processing is a mode S extended squitter. In addition, the ground device 1 uses the position information included in the extended squitter of mode S to specify the position of the own device.

  As shown in FIG. 1, the ground device 1 includes an antenna 10 used for signal transmission / reception, a receiver 11 that receives a signal, an analyzer 12 that analyzes the received signal, and signal processing that processes the analyzed signal. Unit 13 and a calculation unit 14 for calculating the position of the own device from the received signal.

  The receiver 11 outputs the received signal to the analyzer 12 together with the signal reception time. The analyzer 12 analyzes the input signal and outputs the analyzed signal to the signal processing unit 13 and the calculation unit 14 together with the signal reception time. Here, as shown in FIG. 2, the signal output from the analyzer 12 includes “time” when the signal is received, “aircraft identifier” that identifies the aircraft that transmitted the signal, and “the aircraft position”. "Position data" and "flight data" representing the flight status of the aircraft. The position data includes “latitude”, “longitude”, and “altitude” of the aircraft, and the flight data includes “rise rate”, “speed to ground”, and “heading direction” of the aircraft.

  The calculation unit 14 includes a distance specifying unit 141 and a position specifying unit 142 in order to specify the position of the own device from the signal input from the analyzer 12.

  As shown in FIG. 3, the ground device 1 is at point X, and an aircraft transmits a signal (first signal) at point A (first transmission position) at time Ta and then at point B (second transmission position). It is assumed that a signal (second signal) is transmitted again at the time Tb when the movement is performed. In this case, since the position of the point A is included in the first signal and the position of the point B is included in the second signal, the ground device 1 can grasp the points A and B. Also, since the receiver 11 measures the reception time Txa of the first signal and the reception time Txb of the second signal, the ground device 1 has both the reception time Txa of the first signal and the reception time Txb of the second signal. I can grasp it. Furthermore, the time tl required from the transmission time Ta of the first signal to the transmission time Tb of the second signal can be obtained from the distance L and the flight data of the received signal.

  The distance specifying unit 141 first transmits the second signal from the point A which is the position of the aircraft that transmitted the first signal, using the position information of the point A and the position information of the point B included in the received signal. A distance L to point B, which is the position after the aircraft has moved, is obtained. Alternatively, the distance specifying unit 141 obtains the time tl required for the movement of the distance L by using the distance L and the moving speed and nose direction of the aircraft included in the received signal.

  Here, when the distance from point A to point X is R, and the distance from point B to point X is (R + D), distance D is the distance from point X to point A and point X to point B. D = 0 when there is a point A and a point B on a radius R centered on the point X. That is, as shown in FIG. 3, when the aircraft is moving away from the point X, which is the position of the ground device 1, the distance D becomes a positive value, and the time required from transmission to reception of the second signal ( Txb−Tb) becomes longer according to the distance D than the time (Txa−Ta) required from transmission to reception of the first signal. Also, unlike the example shown in FIG. 3, when the aircraft is moving so as to approach the point X that is the position of the ground device 1, the distance D becomes a negative value and the second signal is transmitted. The time required for reception (Txb−Tb) is shorter according to the distance D than the time required for transmission from the transmission of the first signal (Txa−Ta).

  When the distance specifying unit 141 obtains the time tl required for the movement from the point A to the point B (movement of the distance L), the distance identifying unit 141 identifies the distance D using the difference between the obtained time and the reception time of Txa and Txb. To do. That is, if D = 0, the time required to move from the point A to the point B is equal to the difference between the reception time Txa of the first signal and the reception time Txb of the second signal, so (Txb−Txa− The distance D can be specified using tl). Specifically, when the difference between the reception time Txa and the reception time Txb (Txb−Txa) is longer than the time tl required for the aircraft to move from the point A to the point B, D becomes a positive value, and the reception time Txa When the difference in reception time Txb (Txb-Txa) is shorter than the time tl required for the aircraft to move from point A to point B, D is a negative value.

  When the distance specifying unit 141 calculates the distance D, the distance specifying unit 141 generates the distance R by the cosine theorem (Formula 1).

(R + D) ² = R ² + L ² −2RL cos θ (Formula 1)
In (Expression 1), the distance R and the angle θ are unknowns.

  Here, if the distance R and the distance (R + D) are determined, the point R from the point A and the distance (R + D) from the point B can be obtained as the point X. That is, the point X exists on the circumference from the point A to the radius R and from the point B to the radius (R + D). However, the point X1 as well as the point X is a point on the circumference from the point A to the radius R and from the point B to the radius (R + D).

  Therefore, the ground device 1 does not determine the position of the X point (the position of the ground device 1) from the data related to the movement of two points of one aircraft, but obtains the distance from the X point for a plurality of aircrafts. Determine the position. Or the ground apparatus 1 determines the position of X point from the data regarding the movement of three or more points of one aircraft. For this reason, the distance specifying unit 141 generates equations for a plurality of aircraft or generates equations for three or more points of one moving aircraft. At this time, the ground device 1 can specify the position of the ground device 1 more accurately by using the data regarding the movement of a plurality of aircraft than using the data regarding the positions of three or more points of one aircraft. .

  In addition, when the calculating part 14 calculates, it is desirable to extract and calculate the data regarding the aircraft which is carrying out the stable motion like the aircraft which carries out the straight horizontal flight, for example. Specifically, the calculation unit 14 compares the “nose direction”, “speed”, and “effect ratio” of the position data before and after the movement, that is, data that does not change, that is, an aircraft that is moving at constant speed It is desirable to extract and use.

  The distance specifying means 141 generates (Equation 1) using the data relating to the aircraft moved from the point A to the point B to obtain the distance R (Formula 1) and moved from the point A ′ to the point B ′ as shown in FIG. Using the data related to another aircraft, the distance R ′ is calculated by the cosine theorem (Formula 2).

(R ′ + D ′) ² = R ′ ² + L ′ ² −2R′L′cos θ ′ (Expression 2)
In (Expression 2), the distance R ′ and the angle θ ′ are unknown numbers.

  After that, the distance specifying unit 141 solves the simultaneous equations of (Equation 1) and (Equation 2) so as to satisfy the distance R, the angle θ, the distance R ′, and the angle θ ′ to obtain the distance R and the distance R ′. In addition, when it cannot obtain | require only by 2 type | formulas, it calculates | requires using the data of a several body further.

  When the distance from the aircraft position at the time of signal transmission to the point X is obtained by the distance specifying unit 141, the position specifying unit 142 specifies a plurality of position candidates for the ground device 1. In the example of FIG. 5, a point (X point and X1 point) where a radius R centered on point A and a radius (R + D) centered on point B intersect, and a radius R ′ and B centered on point A ′ are used. A point (X point and X2 point) where the radius (R ′ + D ′) centering on the point intersects is set as a candidate for the position of the ground device 1.

  Further, the position specifying unit 142 specifies the position of the ground device 1 (the position of the X point). That is, the position specifying unit 142 specifies the position where the candidates for the point X specified from the data regarding a plurality of aircraft match as the position of the ground device 1.

  Note that the position specifying unit 142 specifies the X point by using a plurality of adjacent X point candidates when the X point candidates are close but do not match. That is, since the value specified by the distance specifying means 141 may be shifted due to an error in position data due to an update interval error or a measurement error in the distance D, the centroids of a plurality of X point candidates are set as X points. Identify.

  As described above, in the ground device 1 according to the embodiment, the position can be specified by using data relating to signals transmitted from a plurality of easy aircraft and signals transmitted from a plurality of positions of the same aircraft. Therefore, it is not necessary to input a position when installing the ground device 1 or specify a position using the CPS, and the ground device 1 can easily set the position.

  As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Further, the present invention naturally includes various embodiments not described herein.

DESCRIPTION OF SYMBOLS 1 ... Ground apparatus 10 ... Antenna 11 ... Receiver 12 ... Analyzer 13 ... Signal processing part 14 ... Calculation part 141 ... Distance specification means 142 ... Position specification means

Claims (1)

A ground device that receives and processes a signal including a transmission time, an identifier of the aircraft, a position of the aircraft, and flight data transmitted from the aircraft,
A transmission time transmitted from the aircraft, an identifier of the aircraft, a position of the aircraft, a distance from the first transmission position that is the position of the aircraft that transmitted the first signal including flight data, and the first transmission position The distance from the second transmission position, which is the position of the aircraft that transmitted the second signal including the transmission time, the identifier of the aircraft, the position of the aircraft, and the flight data transmitted from the aircraft after moving from the aircraft to the ground device Distance specifying means for obtaining
When a plurality of sets of the distance from the first transmission position to the ground device and the distance from the second transmission position to the ground device are obtained by the distance specifying unit, the distance from the first transmission position of each set to the ground device And the distance from the second transmission position to the ground device, each of the ground device position candidates is specified. Position specifying means for specifying the position of the ground device with the position obtained from the plurality of position candidates as the position of the ground device ;
A ground device comprising:

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