JP2000266846A - Radar system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar system which is resistive to mutual interferences even when a plurality of radars are simultaneously used. SOLUTION: Four antennas 1a-1d are rotated synchronously in an equal direction. Whether a direction of each of the synchronously rotated antennas agrees with a plurality of preliminarily set monitor ranges is judged. Based on the judgment result, a radar transmission reception apparatuses 8a-8d transmit and receive radar waves separately for a plurality of time zones, synthesize a plurality of received echoes obtained by the transmission reception, and then visibly display the echoes on a display device 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar system such as an airport surface detection radar system used for controlling the departure and arrival of an aircraft on an airport surface.

[0002]

2. Description of the Related Art Airport detection radars (ASDEs) have conventionally been used for controlling aircraft on an airport.
The ASDE is for detecting an airport surface by rotating a plurality of adjacent antennas. As one method of synchronously rotating the plurality of antennas, for example, Japanese Patent Laid-Open No. 1-19768
There is a multiple radar operation system described in Japanese Patent Publication No.

FIG. 7 is a system diagram showing an embodiment of a synchronous rotation system of a plurality of adjacent antennas as a conventional radar system disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-197885. The system shown in the figure includes antennas 1a and 1b, servo motors 113a and 113b, an antenna control device 11
1a, 111b, and an angle command generator 116. Among these, the angle command generator 116 generates angle commands 115a and 115b for controlling the antenna control devices 111a and 111b, and the antenna control devices 111a and 111b receive these commands. , And outputs control signals 112a and 112b.

[0004] Servo motors 113a and 113b control signals 112 from antenna control devices 111a and 111b.
The antennas 1a and 1b are driven based on a and 112b.
At this time, the servo motors 113a and 113b are connected to the antennas 1a and 1b via the drive shafts 114a and 114b, respectively.
Transmit the driving force to b.

Hereinafter, the operation of the system according to the conventional synchronous rotation method will be described in detail. The angle command generator 116 generates an angle signal synchronized with the rotation of the antennas 1a and 1b,
Angle commands 115a and 11b are given to antenna control devices 111a and 111b, respectively, which are two radar systems of this system.
Give 5b. And each radar system,
In response to this angle command, the antennas 1a and 1b are rotated synchronously.

Here, the antenna control devices 111a and 11a
1b or the antennas 1a and 1b form a servo loop, so that the angle command and the antennas 1a and 1b
There is almost no error from the actual angle of 1b. Therefore, as long as the antenna control devices 111a and 111b generate a synchronized angle command, the antenna is rotated synchronously.

The angle commands 115a and 115b, which are signals generated by the angle command generator 116, have the same rotation speed because the antennas of the two radar systems have the same rotation speed. And signals having different phase differences. Therefore, for the purpose of preventing mutual interference of radar systems, as an example, these signals may have a phase difference of 90 °. Even when there are three or more radar systems, mutual interference can be prevented by appropriately selecting the phase difference between signals generated by the angle command generator 116.

In the conventional ASDE, an aircraft is controlled on an airport surface using one sensor. However, due to recent expansion of airport facilities, runways, and the like, the area monitored by one sensor is widened. In the direction. As a countermeasure against such a situation, a method is adopted in which the location of the sensor is taken into account, and the control is partially performed visually.

[0009]

However, the above-mentioned conventional radar system has a configuration in which mutual interference is prevented by shifting the rotation angle of the antenna. Therefore, when a plurality of radar systems are operated at the same time, there is another problem. However, there is a problem that the radar is easily affected by side lobes, multipaths, and the like.

Further, in the above-mentioned conventional radar system, the monitoring area of the sensor is limited, and an area which cannot be seen by a single antenna is generated. Therefore, the control using a plurality of radar systems according to the expansion of the monitoring area. Performs a problem that mutual interference cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a radar system which is hardly affected by mutual interference even when a plurality of radars are operated simultaneously.

It is another object of the present invention to provide a radar system capable of controlling an entire airport even at a large-scale airport where a single radar cannot control the airport.

[0013]

According to a first aspect of the present invention, there is provided a radar system for detecting a radar by rotating a plurality of antennas, wherein the plurality of antennas are synchronously rotated in the same direction. Means for determining whether the direction of each of the plurality of antennas rotating in synchronization with each other matches a plurality of monitoring ranges set in advance, and dividing the antenna into a plurality of time zones based on the determination result. Provided is a radar system including a transmitting / receiving unit for transmitting / receiving radar radio waves, a combining unit for combining a plurality of reception echoes obtained by the transmission / reception, and a unit for visually displaying the combined echo.

Preferably, the radar system according to the present invention is provided with a plurality of the transmitting / receiving means corresponding to the plurality of antennas. Preferably, the radar system according to the present invention further includes a plurality of switching units corresponding to the plurality of antennas, and the switching unit switches connection between the single transmitting / receiving unit and the plurality of antennas. I do.

[0015] Preferably, the synthesizing means converts the coordinates of the received echo with reference to one of the plurality of antennas. Preferably, the plurality of antennas and the plurality of monitoring ranges correspond one-to-one.

[0016] Preferably, in the radar system according to the present invention, the plurality of antennas are four antennas located at four vertexes of a quadrangle, and the plurality of monitoring ranges are such that the quadrangle is equal to four quadrangles. It corresponds to the four regions obtained separately.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a radar system according to Embodiment 1 of the present invention. The system shown in FIG. 1 has an antenna 1 for transmitting and receiving radar signals.
a, 1b, 1c, 1d, an antenna drive control device 2 for outputting drive control and rotation signals of these antennas to a signal processing unit 6 described later, and circulators 3a, 3b, 3
c, 3d and radar transmitting / receiving devices 8a, 8 for transmitting / receiving radio waves corresponding to the antennas 1a, 1b, 1c, 1d, respectively.
b, 8c, 8d, and a display device 7 for displaying echoes and the like processed (digitally processed) from the signal processing unit 6.

The radar transmitting / receiving devices 8a, 8b, 8
c and 8d are radar transmitters 4a, 4b, 4c,
4d and radar receivers 5a, 5b, 5c and 5d, but since each transmitting and receiving device has the same configuration, in FIG. 1, only the radar transmitting and receiving device 8a has a radar transmitter 4a and a radar receiver which constitute it. 5a is illustrated. Further, the signal processing unit 6 performs transmission timing creation and digital processing of the received signal.

The monitoring range of a radar system for controlling takeoff and landing of an aircraft is generally about 3 to 5 kilometers. This is a range determined by the length of the runway (about 3 km). However, in a large airport where there are two or more runways, control with one radar system is not possible, and It is necessary to adopt a configuration using a system.

In particular, in an airport where a parallel runway exists, a portion such as a control tower that is behind a building may occur, which may hinder the monitoring of the entire airport. For this reason, it is necessary to provide a plurality of radars or a function for compensating for performance deficiencies and weaknesses.

Therefore, the operation of the radar system according to the present embodiment for solving the above problem will be described. FIG.
In order to avoid mutual interference, the radar system shown in (1) adopts a method of synchronously rotating the antennas 1a, 1b, 1c and 1d. That is, the antenna drive control device 2 of the radar system according to the present embodiment performs synchronous control so that all four antennas 1a, 1b, 1c, and 1d rotate in the same direction.

FIG. 2 shows the antennas 1a, 1b, 1c and 1d.
Are shown, and their monitoring areas are shown.
a indicates the area a, the antenna 1b indicates the area b, and the antenna 1c
Monitor the area c, and the antenna 1d monitors the area d. In other words, the radar transmitting / receiving device 8a operates only when the rotation direction of the antenna 1a is within the range of the area a.
A radio wave is transmitted from the radar transmitter 4a via the antenna 1a, and at the same time, an echo of the radio wave is received by the radar receiver 5a.

Next, when the rotation direction of the antenna 1b comes to the range of the area b, the radar transmitting / receiving device 8b transmits and receives radio waves via the antenna 1b. Thereafter, similarly, the radar transmission / reception device 8c performs radio wave transmission and echo reception (transmission / reception control) via the antenna 1c and the radar transmission / reception device 8d via the antenna 1d. In other words, in the system according to the present embodiment, the time zone for transmitting and receiving radio waves from the four antennas 1a to 1d is divided so as to avoid simultaneous transmission of radio waves.

As a result of the time-divided transmission / reception control, the echoes received by the radar transmission / reception devices 8a to 8d are:
The signal is input to the signal processing unit 6 as a reception echo signal. Then, the signal processing unit 6 includes the radar transmitting / receiving devices 8a, 8b,
When displaying the reception echoes from 8c and 8d on the display device 7, the following processing is performed.

That is, the signal processing unit 6 responds to the azimuth signal from the antenna drive control device 2 and
The received echo for each transmission timing received by the radar receiver 5a via the
゜ minutes (that is, the amount corresponding to the area a) is accumulated and output to the display device 7.

Thereafter, similarly, the signal processing section 6 converts the received echo received by the antenna 1b and the radar receiver 5b and the azimuth information at that time into 90 ° (corresponding to the area b),
The received echo received by the antenna 1c and the radar receiver 5c and the direction information at that time are 90 ° (corresponding to the area c), the received echo received by the antenna 1d and the radar receiver 5d, and the azimuth at that time. The information is accumulated for 90 degrees (corresponding to the area d) and is sequentially output to the display device 7.

Eventually, an echo of one screen (360 °) is input to the signal processing unit 6, and the display unit 7 outputs a signal from the signal processing unit 6 in accordance with the azimuth and distance assigned in advance. Based on the antenna angle information (azimuth information) of
Visualize the received echo. The antenna angle information is sent to the display device 7 while being attached to the received echo signal.

FIG. 3 shows a display method for displaying the reception echo of each antenna input from the signal processing section 6. In the system according to the present embodiment, since the reception echo Ta from the antenna 1a is input in the polar coordinates of R-θ, it is converted into XY coordinates based on the antenna 1a. That is, the position of Ta is represented by ΔXa = Ra · cos θa ΔYa = Ra · sin θa

Similarly, the reception echo T from the antenna 1b
b, reception echo Tc from antenna 1c, antenna 1d
For the received echo Td from, the received echo based on the respective antennas 1b, 1c and 1d is converted into XY coordinates.

Since the result of the coordinate conversion is coordinates based on the respective antennas, to display them as one display screen, the coordinate system obtained by combining the echoes received from the respective antennas with the actual coordinates is used. Need to be converted to Therefore, the basic origin of the display is the antenna 1a,
When coordinate conversion is performed for the received echo from each antenna,
It looks like this:

Received echo Ta: Xa = ΔXa, Ya = ΔYa Received echo Tb: Xb = X−ΔXb, Yb = ΔYb Received echo Tc: Xc = X−ΔXc, Yc = Y−ΔYc Received echo Td: Xd = ΔXd, Yd = Y−ΔYd As described above, the reception echo from each antenna is expressed in a coordinate system based on the antenna 1a.

FIG. 4 shows a display example of a radar echo on the display device 7, that is, a case of displaying in a composite coordinate system. As shown in the figure, in the system according to the present embodiment, the echoes of the coordinate system converted by the above-described method are displayed at any of coordinates X1 to Xn and Y1 to Yn. Then, the reception echo of each antenna input from the signal processing unit 6 to the display device 7 is displayed as a composite image on a display screen (not shown) of the display device 7.

As described above, according to the present embodiment, the four antennas are synchronously controlled to rotate in the same direction, and at the same time, the monitoring area is determined for each antenna, By configuring the transmission and reception control for the reception echo for each transmission timing of the radio wave divided by the band, it is possible to sufficiently monitor an area that cannot be monitored by a single antenna, and to obtain a high quality without interference from each antenna. A radar echo display can be obtained.

Further, when the radar system according to the present embodiment is used as an airport surface detection radar, it is possible to cover the entire area of the airport surface, including the area where one antenna cannot be seen, and to integrate based on the received echo. Based on the image display,
More precise control can be performed.

Embodiment 2 Hereinafter, Embodiment 2 of the present invention will be described. FIG. 5 is a diagram showing a configuration of the radar system according to the present embodiment. In the system shown in the figure, the same components as those in the system according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted here.

The operation of the radar system according to the embodiment will be described below. As shown in FIG. 1, the system according to the first embodiment includes the antennas 1a, 1b, 1
c, 1d, the radar transmitting / receiving devices 8a, 8b, 8c, 8
Although d is connected, the radar system according to the present embodiment has a simplified configuration.

That is, the radar system according to the present embodiment includes a transmission / reception switch 10 and a switching control unit 9 built therein, and performs input / output of one radar transmission / reception device 8.
The transmission / reception switching is performed by the switching control unit 9 in accordance with the antenna rotation direction from the antenna drive control device 2. More specifically, the switching control unit 9 receives an azimuth signal from the antenna drive control device 2 and performs the following on / off control of the switching switch in accordance with the signal.

For example, when performing radio wave transmission from the antenna 1a, the switching control unit 9 performs control to close (turn on) the changeover switch 11s and transmit radio waves from the radar transmitter 4 via the antenna 1a. Then, at the reception timing of the echo by the antenna 1a, the switch 11r is closed, and the radar receiver 5 receives the echo of the radio wave.

Hereinafter, the switching control section 9 also controls the switching switches 12 for the antennas 1b, 1c and 1d in accordance with the respective transmission / reception timings, similarly to the case of the antenna 1a.
s, 12r, the changeover switches 13s, 13r, and the changeover switches 14s, 14r are turned on / off. as a result,
The signal processing unit 6 and the display device 7 obtain a predetermined reception echo signal.

As described above, according to the present embodiment, the radar transmitter, the radar receiver, and the switch for switching between the antenna and the antenna provided in correspondence with each antenna are controlled in accordance with the antenna rotation direction. Thus, a radar system can be assembled with a single radar transmitting / receiving device, and the system configuration can be simplified.

Embodiment 3 Hereinafter, Embodiment 3 of the present invention will be described. FIG. 6 is a diagram showing a configuration of the radar system according to the present embodiment. In the system shown in the figure, the same components as those in the system according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted here.

The system according to the present embodiment shown in FIG. 6 has a configuration in which the number of antennas is increased as compared with the system according to the first embodiment, and includes a plurality (n) of antennas. You. That is, in the radar system shown in FIG. 6, mutual interference is avoided by synchronously rotating the antennas 1a to 1n. At this time, the antenna drive control device 2 performs synchronous control so that the n antennas 1a to 1n all rotate in the same direction.

In the system according to this embodiment, for example, n monitoring areas corresponding to antennas are provided, and each antenna transmits and receives radio waves at a predetermined angle. That is, the radar transmitting / receiving devices 8a to 8n are
The respective radio wave transmission and echo reception (transmission / reception control) are performed via n, and as a result of the transmission / reception control, the echoes received by the radar transmission / reception devices 8a to 8n are input to the signal processing unit 6 as reception echo signals.

With this configuration, in the system according to the present embodiment, the monitoring area is subdivided, antennas corresponding to the respective areas are provided, and radio wave transmission and echo reception are executed, so that the system can be more detailed. Monitoring can be performed.

The system according to the second embodiment shown in FIG. 5 is applied to the system according to the present embodiment, and the radar transmitter, the radar receiver, and the antenna are associated with each antenna. A changeover switch may be provided. With this configuration, the same effect as that of the system according to the second embodiment can be obtained, but the illustration of the system configuration is omitted here.

[0046]

As described above, according to the radar system of the first invention, in a radar system for detecting a radar by rotating a plurality of antennas, means for synchronously rotating the plurality of antennas in the same direction. Means for determining whether the direction of each of the plurality of antennas rotating in synchronization with each other matches a plurality of monitoring ranges set in advance, and dividing the antenna into a plurality of time zones based on the determination result. By providing a transmitting / receiving means for transmitting / receiving radar radio waves, a synthesizing means for synthesizing a plurality of received echoes obtained by the transmitting / receiving, and a means for visually displaying the echo after the synthesizing, it is impossible to monitor with a single antenna In other words, a so-called blind spot area can be sufficiently monitored, and at the same time, a high-quality echo display without interference from each antenna can be obtained.

Further, by providing a plurality of transmitting and receiving means corresponding to a plurality of antennas, the processing of transmitting and receiving radar radio waves can be smoothly performed. Further, a plurality of switching means corresponding to a plurality of antennas are provided, and these switching means perform connection switching between the single transmitting / receiving means and the plurality of antennas, thereby greatly simplifying the system configuration. Can be

Further, since the synthesizing means converts the coordinates of the received echo with reference to one of the plurality of antennas, it is possible to display an image using a specific antenna as a basic origin of the display. Furthermore, the reliability of the radar detection result is improved by associating the plurality of antennas with the plurality of monitoring ranges on a one-to-one basis and determining the monitoring area.

Further, in the radar system according to the present invention, the plurality of antennas are four antennas located at four vertexes of a quadrangle, and the plurality of monitoring ranges are
By associating the quadrangle with four regions obtained by equally dividing the quadrangle, it is possible to realize highly reliable radar detection with a small number of antennas.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a radar system according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing an antenna arrangement and a monitoring area in the system according to the first embodiment.

FIG. 3 is a diagram showing a method of displaying a received echo according to the first embodiment.

FIG. 4 is a diagram showing a display example of radar echo on the display device according to the first embodiment.

FIG. 5 is a block diagram showing a configuration of a radar system according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a configuration of a radar system according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a conventional radar system.

[Explanation of symbols]

1a, 1b, 1c, 1d ... antenna, 2 ... antenna drive control device, 3a, 3b, 3c, 3d ... circulator,
4a, 4b, 4c, 4d ... radar transmitters, 5a, 5b,
5c, 5d: radar receiver, 6: signal processing unit, 7: display device, 8a, 8b, 8c, 8d: radar transmitting / receiving device, 9
... Switch control unit, 10 ... Transmission / reception switch, 11s, 11r,
12s, 12r, 13s, 13r, 14s, 14r ... changeover switches

Claims (6)

[Claims] 1. A radar system for performing radar detection by rotating a plurality of antennas, wherein: a means for synchronously rotating the plurality of antennas in the same direction; Means for judging whether or not they match a plurality of set monitoring ranges; transmitting / receiving means for transmitting / receiving radar radio waves by dividing into a plurality of time zones based on the judgment result; and A radar system comprising: combining means for combining received echoes; and means for visually displaying the combined echoes. 2. The radar system according to claim 1, wherein a plurality of said transmitting / receiving means are provided corresponding to said plurality of antennas. 3. The apparatus according to claim 2, further comprising a plurality of switching units corresponding to the plurality of antennas, wherein the switching unit switches connection between the single transmitting / receiving unit and the plurality of antennas. Item 4. The radar system according to item 1. 4. The radar system according to claim 1, wherein said synthesizing unit performs coordinate conversion on the reception echo based on one of the plurality of antennas. 5. The radar system according to claim 1, wherein the plurality of antennas and the plurality of monitoring ranges correspond one to one. 6. The plurality of antennas are four antennas located at four vertexes of a rectangle, and the plurality of monitoring ranges are divided into four areas obtained by equally dividing the rectangle into four rectangles. The radar system according to claim 5, wherein the radar system is compatible.