JP2000131454A - Detecting device for moving body and detecting apparatus for position of airplane by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting device for a moving body, which can easily decide a GPS satellite suitable for detecting the moving body even when a receiving antenna is buried. SOLUTION: An antenna 6 which receives radio waves which are transmitted from a plurality of GPS satellites is provided. In addition, a reception means 7 by which the reception intensity of radio waves and the angle of elevation of a GPS satellite are extracted from information contained in the radio waves received by the antenna 6 is provided. In addition, a moving-body existence judgment means 8 by which the GPS satellite used to detect a moving body is selected out of the plurality of GPS satellites on the basis of the reception intensity and the angle of elevation, and which detects the moving body on the basis of a change in the reception intensity of the radio waves transmitted by the selected GPS satellite is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object detecting device for detecting a moving object and an aircraft position detecting device using the same, and more particularly to a moving object detecting device using radio waves from GPS satellites and using the same. The present invention relates to an aircraft position detection device.

[0002]

2. Description of the Related Art As a moving object detecting device for detecting a moving object such as a vehicle, a transmitter for transmitting an electromagnetic wave such as a microwave and a receiver for receiving the electromagnetic wave are provided, and the electromagnetic wave is blocked by the moving object. In other words, there has been devised a moving object detection device that detects that a moving object is located between a transmitter and a receiver due to a decrease in the reception level of electromagnetic waves in the receiver.

[0003] As one example, International Publication Number WO97 /
Japanese Patent No. 04337 describes a moving object detection device using radio waves transmitted by GPS satellites. As described in the above publication, the use of radio waves transmitted by GPS satellites makes it possible to configure a moving object detection device without newly providing a transmitter for detecting a moving object.

[0004]

In the above prior art, G
Although the receiving antenna is exposed on the ground surface in order to receive the radio wave transmitted by the PS satellite, it is conceivable that the receiving antenna may come into contact with a moving object, and it is necessary to consider the strength of the receiving antenna. Further, even if the receiving antenna is buried in the ground to solve this problem, the directivity becomes complicated due to the structure of the housing for accommodating the receiving antenna. It is very difficult to determine a GPS satellite to be used for detection of a moving object from the satellite. An object of the present invention is to provide a moving object detection device that can easily determine a GPS satellite suitable for detecting a moving object even when a receiving antenna is embedded.

[0005]

A feature of the present invention that achieves the above object is that when a mobile object is detected using radio waves transmitted from a plurality of GPS satellites, the reception intensity of the radio waves and the elevation angle of the GPS satellites GPS satellites to be used for detecting a moving object are selected from the plurality of GPS satellites based on
It is to detect a moving object based on a change in the reception intensity of a radio wave transmitted by a PS satellite.

According to the present invention, a GPS satellite used for detecting a moving object is selected based on the reception intensity of a radio wave. Therefore, when the antenna for receiving the radio wave is buried, the directivity of the antenna becomes complicated. However, a GPS satellite suitable for detecting a moving object can be easily selected.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an aircraft position detecting device according to a preferred embodiment of the present invention. Note that the aircraft position detection device of the present embodiment uses a plurality of moving object detectors to detect aircraft and other vehicles (hereinafter, referred to as work vehicles) on routes along which aircraft travel, such as airport taxiways and aprons. This is to detect the position.

In FIG. 1, an AC power supply 1 supplies AC power to lamps 5a to 5n via a power line 2 and transformers 3a to 3n to turn on the lamps 5a to 5n. In addition,
The lamps 5a to 5n are buried in a guideway or the like of an aircraft and used for guiding an aircraft, and several methods of controlling turning on and off are already known.

The AC power output from the AC power supply 1 is also supplied to the mobile detectors 4a to 4n. Moving object detector 4
a to 4n are buried in a taxiway or the like of an aircraft to detect whether an aircraft exists above the aircraft. In the moving object detector 4a, the input AC power is AC /
After being converted from AC power to DC power by the DC converter 10, the power is supplied to each unit as power for driving the receiving unit 7, the mobile unit presence / absence determining unit 8, and the information transmitting unit 9 constituting the mobile unit detector 4 a. . In this embodiment, the moving body detector 4a among the moving body detectors 4a to 4n will be described, but the other moving body detectors have the same configuration.

In the moving object detector 4a, the antenna 6
Is an antenna for receiving radio waves transmitted from a plurality of GPS satellites, and outputs the received radio waves to the receiving unit 7 as signals. The receiving unit 7 includes a GPS unit included in the input signal.
It decodes navigation data and organizes satellite information for each GPS satellite. Note that GPS navigation data refers to each GP
The unique data of the S satellite, which includes information such as the individual identification number of the GPS satellite, the apparent elevation angle from the position where the antenna is installed (hereinafter, simply referred to as elevation angle), the apparent azimuth angle, the radio wave reception intensity, and the like. . The receiving unit 7 outputs the satellite information arranged for each GPS satellite to the mobile unit presence / absence determining unit 8. The processing of the GPS navigation data in the receiving unit 7 is generally known as described in Japanese Patent Application Laid-Open No. 63-191880, and a detailed description thereof will be omitted.

The moving body presence / absence determining unit 8 determines whether or not a moving body is present above the moving body detector 4a (specifically, the antenna 6) based on the input satellite information. The result is output to the information transmitting unit 9.

FIG. 5 shows the structure of the moving body presence / absence determining section 8.
The satellite information input to the moving object presence / absence determination unit 8 is input to the data distribution unit 51. The data distribution unit 51 determines the elevation angle and the reception intensity of the radio wave (hereinafter simply referred to as reception intensity) of the input satellite information by using the mobile arrival detection units 52a to 52n.
And output to the moving body detachment detection units 53a to 53n,
At this time, based on the individual identification numbers of the GPS satellites included in the satellite information, the mobile object arrival detectors 52a to 52n and the mobile object departure detectors 53a to 53n corresponding to the respective GPS satellites.
Output the elevation angle and the reception intensity respectively corresponding to. That is, the moving object arrival detecting units 52a to 52n and the moving object leaving detecting units 53a to 53n are provided in accordance with the number of GPS satellites, and are respectively associated with one GPS satellite in advance.

FIG. 6 shows the structure of the moving body arrival detecting section 52a. Note that the other moving body arrival detection units have the same configuration. The elevation angle and the reception intensity input to the moving object arrival detection unit 52a are input to the data separation unit 61, and the data separation unit 61
Separates the two data, and outputs the reception intensity to the reception intensity reduction detection unit 62 and the satellite data use evaluation unit 63, and the elevation angle to the satellite data use evaluation unit 63, respectively.

FIG. 8 shows the configuration of the reception intensity decrease detection section 62. In the reception intensity decrease detection unit 62, the data classification unit 6
The reception intensity input from 1 is an LPF (low-pass filter) 8
1 to the comparators 82 and 83. Note that LP
F81 is provided for cutting noise.

The comparator 82 has a delay circuit, and calculates a difference between the reception intensity delayed by the delay circuit and the reception intensity not passing through the delay circuit. In other words, the difference between the current reception intensity and the reception intensity one second before is calculated by giving a delay (one second delay in this embodiment) to the reception intensity by the delay circuit. From this difference, it is determined whether or not the reception intensity has decreased. If the reception intensity has decreased, the difference, that is, the amount of decrease in the reception intensity is obtained and compared with a preset first reference value. As a result of the comparison, “1” is output when the reduction amount is equal to or more than the first reference value, and “0” is output when the reduction amount is equal to or less than the first reference value. The first reference value is
The minimum value of the amount of decrease in the reception intensity when the radio wave of the GPS satellite is cut off by the moving object is set. Since this minimum value changes depending on the installation state of the antenna, it is obtained by an experiment.

On the other hand, the comparator 83 also has a delay circuit, and compares the reception intensity delayed by the delay circuit (1 second delay in the present embodiment) with a preset first threshold value. As a result of the comparison, “1” is output when the reception intensity one second before is equal to or higher than the preset first threshold, and “0” is output when the reception intensity is equal to or lower than the first threshold. Here, the value set as the first threshold will be described. Since GPS satellites are always moving, GPS was able to receive radio waves at some point
Even if a satellite passes over time, it may move to a position where radio waves are blocked by an obstacle such as a building. In that case, it was found that the reception intensity gradually decreased to a certain value and then decreased sharply. As described above, the reception strength is also reduced by the movement of the GPS satellites. Therefore, it is necessary to distinguish between the reduction of the reception strength due to the movement of the GPS satellites and the reduction of the reception strength due to the arrival of the moving object. For this purpose, a value of the reception intensity one second before the reception intensity sharply decreases when the reception intensity decreases due to the movement of the GPS satellite is set as the first threshold value. Since the value of the reception intensity changes depending on the installation state of the antenna, it is obtained by an experiment. Also, since the value of the reception intensity differs for each GPS satellite, an appropriate value is set for each GPS satellite. Alternatively, the largest value may be commonly set.

The AND circuit 84 receives the output signals of the comparators 82 and 83 and outputs "1" when both are "1", and outputs "0" when both or one of them is "0". I do.

The output signal of the AND circuit 84 is output to the signal holding unit 64 as a detection result of the reception intensity reduction detecting unit 62. According to the reception intensity decrease detection unit 62, “1” is output when the reception intensity decreases due to the arrival of the moving object.

Here, the operation of the reception intensity decrease detection unit 62 when the reception intensity decreases due to the movement of the GPS satellite (when the radio wave is blocked by a building or the like) will be described. As described above, when the reception intensity decreases due to the movement of the GPS satellite, the reception intensity gradually decreases to a certain value, but the amount of decrease at that time increases as the value exceeds the first reference value set in the comparator 82. Therefore, the output of the comparator 82 becomes “0”. Therefore, regardless of the output of the comparator 83, the output of the AND circuit 84 is "0". When the reception intensity gradually decreases and reaches the first threshold value, that is, the value one second before the reception intensity sharply decreases, the output of the comparator 83 becomes “0”.
Therefore, even if the output of the comparator 82 becomes “1” due to a sudden decrease in the reception intensity, the output of the comparator 83 is “0” at that time, and the output of the AND circuit 84 is “0”. Become. As described above, when the reception intensity decreases due to the movement of the GPS satellite (when the radio wave is blocked by a building or the like), the output of the reception intensity decrease detection unit 62 becomes “0”. That is, “1” is output from the reception intensity decrease detection unit 62 only when the reception intensity decreases due to the arrival of the moving object.

In FIG. 6, the signal holding unit 64 receives the output of the reception strength reduction detection unit 62 and the output of the moving object arrival determination unit 54, and outputs “1” from the reception strength reduction detection unit 62. Then, “1” is output until “1” is output from the mobile object arrival determination unit 54. This is performed because there is a difference in the time required for the reception intensity to decrease when a mobile unit arrives depending on the satellite. As will be described later, the mobile object arrival determination unit 54 outputs “1” when it is determined that the mobile object has arrived. The output of the signal holding unit 64 is input to the information transmitting unit 65.

The satellite data use evaluation section 63 evaluates whether or not the corresponding satellite is suitable for moving object detection based on the reception intensity and the elevation angle. FIG. 9 shows the satellite data use evaluation unit 63.
Is shown. In FIG. 9, the reception intensity is input to a comparator 91. The comparator 91 compares the input received signal strength with a preset first threshold value, and outputs “1” when the received signal strength is smaller than the first threshold value, and outputs “0” when the received signal strength is larger than the first threshold value. The output signal of the mobile object presence detection unit 56 is also input to the satellite data use evaluation unit 63, and this output signal is input to the delay circuit 92. Note that, as described later, the output signal of the moving object presence detection unit 56 is “1” when the moving object is present above the antenna 6 and is “0” when the moving object is not present. . The output signal of the delay circuit 92 is NO
After being inverted by the T circuit 93, it is input to the AND circuit 94. The output signal of the comparator 91 is also input to the AND circuit 94, and the logical product of both inputs is calculated. That is, when both inputs are "1", "1", and both or either one is "0".
In this case, "0" is output. The comparator 91, the delay circuit 92, the NOT circuit 93, and the AND circuit 94 output "1" when the reception strength is low even though the moving object is not present above the antenna. In other words, “1” is output when the reception strength of the radio wave is reduced due to a part of the radio wave being blocked by an obstacle such as a building.

The elevation angle is input to a comparator 95. Comparator 9
Reference numeral 5 compares the elevation angle with the second reference value, and outputs "1" when the elevation angle is smaller than the second reference value, and outputs "0" when the elevation angle is larger than the second reference value. Here, the value set as the second reference value will be described. When detecting a vehicle whose body is located at a certain height, such as an aircraft, even if the moving object is above the antenna, the radio wave of the GPS satellite with a small elevation angle passes below the body and is blocked by the moving object. It may be received by the antenna without receiving. Radio waves from GPS satellites with such an elevation angle are not suitable for detecting a moving object and must be excluded. Therefore, the maximum value of the elevation angle of the GPS satellite from which radio waves are detected even when the moving object is located above the antenna is set as the second reference value. Note that the value of the elevation angle varies depending on the installation state of the antenna, and is obtained by an experiment.

The output signal of the comparator 95 and an AND circuit 94
Is input to the NOR circuit 96. The NOR circuit 96 outputs “1” when both input signals are “0”,
"0" when one or both of the inputs are "1"
Is output. The output of the NOR circuit 96 is output to the information transmission unit 65 as the output of the satellite data use evaluation unit 63. By such a satellite data use evaluation unit 63, when the moving object is not above the aircraft detection device 4a (antenna 6), the reception intensity is equal to or less than the first threshold value, or the elevation angle is higher than the second reference value. Is also smaller, "0" is output. Conversely, if none of the above applies, “1” is output. Note that “0” indicates that the corresponding GPS satellite is not suitable for mobile object detection, and “1” indicates that the corresponding GPS satellite is not suitable for mobile object detection.
Indicates that the satellite is suitable for moving object detection.

In FIG. 6, the output signals of the signal holding unit 64 and the satellite data use evaluation unit 63 are input to the information transmission unit 65. The information transmitting unit 65 sends two pieces of information indicating whether the corresponding GPS satellite is suitable for detecting the moving object and whether the reception intensity has decreased to the moving object arrival determining unit 54 as an output of the moving object arrival detecting unit 52a. Output. The output signal of the mobile object arrival detection unit 52a is 2-bit data as shown in FIG. 12, and the upper bits indicate whether the corresponding GPS satellite is suitable for mobile object detection, and the lower bits indicate Indicates whether the reception strength has decreased. That is, "0
“0” and “01” indicate that the corresponding GPS satellite is not suitable for detecting the moving object, and “10” indicates that the arrival of the moving object is not detected. "11" indicates that the arrival of the moving object has been detected. Note that the moving body arrival detection unit 52
The mobile object arrival detectors other than a also output the information on the corresponding satellite to the mobile object arrival determiner 54.

FIG. 11 shows the configuration of the mobile object arrival determination section 54. Each output signal of the moving body arrival detection units 52a to 52n is input to the data extraction unit 111. The data extraction unit 111 selects, from the output signals of the mobile object arrival detection units 52a to 52n, the satellite for which the corresponding satellite has been determined to be suitable for mobile object detection, that is, the one whose data high-order bit is "1". Then, data indicating whether the reception strength corresponding to the satellite has decreased, that is, the lower bits
Output to The AND circuit 112 calculates the logical product of the input lower-order bits, and outputs the result to the mobile unit presence detecting unit 56.
Output to The output of the AND circuit 112 is “1” when all inputs are “1”. That is, when the reception intensity of all the satellites determined to be suitable for the mobile object detection is reduced, “1” is output as the mobile object has arrived. As described above, the moving body arrival detection unit 5
2a to 52n and the mobile object arrival determination unit 54 can detect that the mobile object has arrived above the antenna 6.

Next, the moving body separation detecting sections 53a to 53n will be described. FIG. 7 shows the configuration of the moving body detachment detection unit 53a. In addition, the moving body separation detecting units 53a to 53n all have the same configuration. In FIG. 7, the data distribution unit 5
The reception intensity and elevation angle output from the data extraction unit 71
Is input to The data extraction unit 71 extracts the reception intensity from the above, and outputs the extracted reception intensity to the reception intensity increase detection unit 72 and the satellite data use evaluation unit 73. In addition, the reception intensity rise detection unit 7
The output of the moving object presence detection unit 56 is also input to 2.

FIG. 10 shows the configuration of the reception intensity rise detecting section 72. In the reception intensity increase detection section 72, the reception intensity is input to the comparator 101. The comparator 101 has a delay circuit, and calculates a difference between the reception intensity delayed by the delay circuit and the reception intensity not passing through the delay circuit. In other words, the reception intensity is delayed by the delay circuit (1 in this embodiment).
(A second delay) to calculate the difference between the current reception intensity and the reception intensity one second before. From this difference, it is determined whether or not the reception strength has increased. If the reception strength has increased, the difference, that is, the amount of increase in the reception strength is determined and compared with a first reference value set in advance. As a result of the comparison, “1” is output if the amount of increase is equal to or greater than the first reference value, and “0” is output if the amount of increase is equal to or less than the first reference value.

On the other hand, the output signal of the object presence detector 56 is
AND via delay circuit 102 (providing a one second delay)
The signal is input to the circuit 103. AND circuit 103 is a comparator
101 and the output of the delay circuit 102 are input, and "1" is output when both inputs are "1", and "0" is output when either or both of the inputs are "0". According to the reception intensity increase detection unit 72, “1” is output when the presence of the moving object is detected by the object presence detection unit 56 one second before and the reception intensity increases. That is, “1” is output when the receiving strength increases due to the moving body detaching from above the antenna 6. It should be noted that even when no moving object exists above the antenna 6,
When the GPS satellite moves from a state in which the radio wave is cut off by an obstacle such as a building to a state in which the radio wave is not cut off by the obstacle, the reception intensity increases. Since the condition is that the output of the presence detection unit 56 is “1” one second before, it is possible to detect only an increase in the reception strength due to the separation of the moving object.

In FIG. 7, the output of the reception strength increase detection section 72 and the output of the moving body separation determination section 55 are input to the signal holding section 74, and the signal holding section 74 is provided with the reception strength increase detection section 7.
When “1” is output from 2, the moving body separation determination unit 5
"1" is output from "5" until "1" is output. This is performed because there is a difference in the time required for the reception strength to increase when the moving object leaves the satellite, depending on the satellite. Note that the moving body leaving determination unit 55 outputs “1” when determining that the moving body has left. The output of the detection signal holding unit 74 is output to the information transmitting unit 75.

On the other hand, the satellite data use evaluation unit 73 compares the input reception strength with a preset second threshold value,
When the reception intensity is a value exceeding the second threshold value, the corresponding satellite is evaluated as being suitable for moving object detection, and “1” is output to the information transmitting unit 75. When the reception intensity is equal to or less than the second threshold, the corresponding satellite is evaluated as not suitable for detecting the moving object, and “0” is output to the information transmitting unit 75. In this embodiment, 0 is set as the second threshold. The satellite data use evaluation unit 73 determines that a GPS satellite whose radio wave reception intensity is 0 because radio waves are blocked by an obstacle such as a building is not suitable for mobile object detection.

The information transmitting section 75 receives two information indicating whether or not the satellite is suitable for detecting a moving object and whether or not the reception intensity has increased, as the output of the moving object detachment detecting section 53a, and outputs the information from the moving object detachment determining section 55a. Output to In addition, the moving body detachment detection unit 53
The output signal a is 2-bit data as shown in FIG. 14, where the upper bits indicate whether the satellite is suitable for mobile object detection and the lower bits indicate whether the reception strength has increased. . That is, “00” and “01” indicate that the moving object is not suitable for detection, and “10” indicates that the separation of the moving object is not detected. Also, “11” indicates that the separation of the moving object has been detected. It should be noted that the moving body separation detecting sections other than the moving body separation detecting section 53a also output the above information on the corresponding satellites to the moving body separation determining section 55.

Next, the moving body leaving determination section 55 will be described. FIG. 13 shows the configuration of the moving body separation determination unit 55.
In the moving body detachment determination section 55, the moving body detachment detecting section 53
Outputs of a to 53n are input to the data extraction unit 131. The data extraction unit 131 selects, from the input information, a satellite determined to be suitable for moving object detection, that is, a satellite whose data high-order bit is “1”, and the reception strength corresponding to the satellite is selected. Data indicating whether the signal has risen, that is, lower bits are output to the logic circuit 132. When two or more low-order bits of the input M lower-order bits are “1”, the logic circuit 132 determines that the moving body has left, and sends a “ 1 "is output. On the other hand, of the input M lower bits,
If there is one or less "1", "0" is output. Note that “1” indicates that the moving body has left from above the antenna 6. As described above, the moving body detachment detecting unit 53
It is possible to detect that the moving body has left from above the antenna 6 by the a to 53n and the moving body separation determination unit 55.

FIG. 15 shows the structure of the moving object presence detecting section 56. In the moving object presence detecting unit 56, the output of the moving object arrival determining unit 54 is input to the OR circuit 151. When the output of the moving body arrival determination unit becomes “1”, the OR circuit 15
The output of 1 becomes “1”. At that time, the moving body separation determination unit 5
Since the output of No. 5 is “0”, the output of the NOT circuit 152 becomes “1”. Therefore, the output of the AND circuit 153 is “1”. The output of the AND circuit 153 is
Since the signal is input to the OR circuit 151 via the switch 54, the output of the OR circuit 151 remains “1” even if the output of the moving object arrival determination unit 54 changes to “0”, and the NOT circuit 152
Unless the output of the AND circuit 153 becomes “0” and the output of the AND circuit 153 becomes “0”, the output of the OR circuit 151 becomes “0”.
Does not. When the output of the moving body separation determination unit 55 becomes “1” and the output of the NOT circuit 152 becomes “0”, AND
The output of the circuit 153 becomes “0”. That is, the AND circuit 153 outputs “1” from when “1” is input from the moving body arrival determination unit 54 to when “1” is input from the moving body leaving determination unit 55. That is, "1" is output while the mobile object is present above the antenna 6, and "0" is output when the mobile object is not present. The output of the AND circuit 153 is input to the moving object arrival detecting units 53a to 53n, the moving object leaving detecting units 53a to 53n, and the information transmitting unit 9 as outputs of the moving object presence detecting unit 56 and the moving object presence / absence determining unit 8.

In FIG. 1, the information transmitting section 9 determines whether the input judgment result (the presence or absence of a moving body) is in advance and the moving body detector 4a.
Is transmitted to the information integration unit 11 by the power line carrier method using the power line 2. By using the power line carrier method for transmitting information as described above, information can be transmitted via the power line 2 for supplying the output power of the AC power supply 1, so that it is necessary to separately provide a signal line for transmitting information. Cost can be prevented. The power line carrier technology is described in Japanese Patent Application Laid-Open No. 10-9258.
Since it is known from Japanese Patent Publication No. 8, etc., its detailed contents will not be described.

The moving body detector 4a has been described above. However, the other moving body detectors have the same configuration and operation, and the result of determining the presence or absence of a moving body at the position of each moving body detector and the moving body detector The address is transmitted to the information integration unit 11.

The information integrating unit 11 includes mobile object detectors 4a-4
Based on the address of the moving object detector sent from n and the result of the presence / absence judgment of the corresponding moving object, it is determined at which position what kind of moving object exists.

FIG. 16 shows the configuration of the information integrating unit 11. The address of the moving object detector and the presence / absence determination result sent to the information integration unit 11 are input to the detection information receiving unit 161.
The detection information receiving unit 161 analyzes the data transmitted by the power line carrier method, and outputs the analysis result to the data distribution unit 162. The data distribution unit 162 sorts the input data for each mobile object detector, and
63. The moving object type determination unit 163 determines whether the moving object detected by each moving object detector is an aircraft or another vehicle.

The specific configuration and operation of the moving object type determination section 163 will be described with reference to FIG. As shown in FIG. 17, the presence / absence determination result of the moving object corresponding to the moving object detectors 4a to 4g is input to the moving object type determination unit 163. When it is determined that there is a moving object, “01” (binary number) is input, and when it is determined that there is no moving object, “00” (binary number) is input. Therefore, in the case of FIG. 17, the presence / absence determination result corresponding to the moving object detectors 4a, 4e, and 4g is "00", and the moving object detectors 4b to 4d and 4f are provided.
Is "01". Note that the moving object type determination unit 163 handles data in binary numbers. Here, the flow of signals regarding the moving object detector 4a will be described. The presence / absence determination result corresponding to the moving object detector 4a is input to the AND circuits 175a and 175b and the detection data generation unit 177a. Now, since the presence / absence determination result corresponding to the moving object detector 4a is “00”, the AND circuit 17
The outputs of 5a and 175b are "00" irrespective of the other inputs, and the output of OR circuit 176a is also "00". In the detection data generation unit 177a,
Since “00” is input to the multiplier 178, the output is also “0”.
0 ", and the adder 179 calculates" 00 + 00 ", and outputs" 00 ". The output of the detection data generation unit 177a obtained in this way is input to the data combination unit 164 as a mobile object type determination result corresponding to the mobile object detector 4a. The detection data generation units 177b to 177
f has the same configuration as the detection data generation unit 177a.

Next, the flow of signals for the moving object detector 4b will be described. The presence / absence judgment result corresponding to the moving object detector 4b is input to the AND circuits 175b and 175c and the detection data generation unit 177b. Since the presence / absence determination result corresponding to the moving body detector 4a is “00” and the presence / absence determination result corresponding to the moving body detectors 4b and 4c is “01”, the output of the AND circuit 175b is “00”, and The output of the circuit 175c is "01". Therefore, the output of the OR circuit 176b is "01". In the detection data generation unit 177b,
Since “01” is input to the multiplier 178, the output is “1”.
In addition, the adder 179 calculates “01 + 10” and outputs “11”. The output of the detection data generation unit 177b obtained in this manner is input to the data combination unit 164 as a mobile object type determination result corresponding to the mobile object detector 4b.

The signal flow of the moving object detector 4f will be further described. The result of the presence / absence judgment corresponding to the moving object detector 4f is input to AND circuits 175f and 175g and a detection data generation unit 177f. Since the presence / absence determination result corresponding to the moving body detector 4f is "01" and the presence / absence determination result corresponding to the moving body detectors 4e and 4g is "00", the outputs of the AND circuits 175f and 175g are "00". And the output of the OR circuit 176b is also "00". Detection data generator 1
At 77f, since “01” is input to the multiplier 178, the output is “10”, and the adder 179 is “00 + 1”.
"0" is calculated and "10" is output. The output of the detection data generation unit 177f obtained in this way is input to the data combination unit 164 as a mobile object type determination result corresponding to the mobile object detector 4f.

177c, 1 in the same manner as described above.
“11” is output from 77d, and “0” is output from 177e.
"0" is output. As can be seen from these output results, when the moving object detector does not detect the moving object, “00” is detected, and the moving object is not detected by the adjacent moving object detector. In this case, “10” is output, and “11” is output when the moving object is detected and one of the adjacent moving object detectors detects the moving object.

FIG. 18 shows the output data of the moving object type determination unit 163 and its meaning. As shown in the figure, the presence / absence of a moving object and the type of the moving object are represented by the values. That is, it indicates that there is no moving object above the moving object detectors 4a and 4e to which "00" has been output as the corresponding determination result. In addition, it indicates that a work vehicle exists above the moving object detector 4f to which "10" has been output as the corresponding determination result. Further, "1"
1 "indicates that an aircraft is present above the moving object detectors 4b to 4d. The vehicle of the moving object is determined based on the arrangement of the moving object detectors that have detected the moving object. This focuses on the fact that the length of the vehicle body differs between the aircraft and the work vehicle. In order to determine the type of the moving body in this manner, the total length of the work vehicle What is necessary is just to set an interval of less than half of the total length of the aircraft.

The data integration unit 164 sorts the output data (type determination result) of the mobile unit type determination unit 163 into addresses indicating the mobile unit detectors 4a to 4n and corresponding type determination results, and displays the detection result. Send to section 12.

The detection result display section 12 displays the state of the moving object at the airport based on the input address and the type determination result. FIG. 19 shows a display example on the detection result display unit 12. As shown in the figure, the detection result display unit 12
The guideway 191, the apron 192, the spot 193, and the like are displayed, and the position of the moving object detector is indicated by a circle. Of the moving object detectors, those that do not detect the moving object are indicated by white circles, those that detect the aircraft are indicated by black circles, and those that detect the work vehicle are indicated by the shaded circles. In addition, the meaning of each display is shown in the description column of another frame. By displaying in this way, the position and type of the moving object at the airport can be grasped at a glance. Further, by detecting and displaying the position of the moving body in real time, the moving direction and the moving speed of the moving body can be grasped.

FIG. 2 is a structural diagram of the moving object detector of this embodiment.
FIG. The lamp housing 21 is almost buried under the ground 22, and a power line pipe 23 through which the power line 2 passes is connected. The power line 2 is connected to a transformer 3a, and the transformer 3a is connected to a moving object detector 4a and a lamp 5a.
Light from the lamp 5a is reflected by the reflecting mirror 24 and emitted to the outside through the glass 25. The antenna 6, which is a part of the moving object detector 4a, is installed in a space that is not shielded from the outside by an electromagnetic field. For example, as shown in FIG.
Since the lower part of 4 and the like can receive an external radio wave through the glass 25, the lower part and the like are installed at such a position. Even at a position where direct radio waves cannot be received, it should be installed at a position where reflected waves, refracted waves, wraparound waves, etc. can be reliably received.
By burying the antenna 6 as shown in the figure, it is not necessary to consider the load-bearing performance (strength) of the antenna 6.
In this embodiment, the moving object detector 4a is embedded in the lamp housing for ease of construction. However, the moving object detector 4a and the antenna 6 can be made independent.

FIG. 3 is a view of the housing 21 shown in FIG. 2 as viewed from above. Azimuth angles of 90 ° and 270 as shown
Glass 25 for emitting the light of the lamp 5a
Is arranged. The pure directivity of the antenna 6 is a general figure-of-eight directivity having a peak at the upper side, but when the housing 21 is installed inside the housing 21 due to such a structure, the antenna 6 has The directivity is theoretically the directivity shown in FIG. FIG. 4 can be used for detecting a moving object (a certain receiving strength can be obtained with the antenna 6).
The range of the GPS satellite is represented by the relationship between the azimuth and the elevation. As shown in the figure, when the elevation angle is large, radio waves can be received regardless of the azimuth angle, but when the elevation angle is small, radio waves can be received only in the direction of the glass part of the lamp housing. A ° in the drawing is an angle corresponding to the second threshold. That is, a radio wave from a GPS satellite having an elevation angle equal to or smaller than A ° is not used for mobile object detection because it may pass under the body of the aircraft and be detected by the antenna 6. It should be noted that the directivity shown in FIG. 4 is a theoretical directivity for facilitating the explanation, and actually becomes more complicated depending on the installation state of the antenna. Therefore, it is very difficult to determine a GPS satellite suitable for mobile object detection from the elevation angle and the azimuth angle. In the present embodiment, the GPS satellite to be used is determined based on the elevation angle and the reception strength of the radio wave, so that it is possible to cope with the case where an antenna having a complicated directivity is used.

The present embodiment described above is an aircraft position detecting apparatus in which the moving object detector is applied to the position detection of an aircraft at an airport, but is also applied as a moving object detector on a general road, a track or the like. be able to. Further, in this embodiment, a plurality of satellites such as GPS satellites that transmit radio waves of the same frequency are used. However, by supporting a plurality of receivers, a group of satellites having different frequencies such as GLONASS may be used. it can.

[0049]

According to the present invention, a GPS satellite suitable for detecting a moving object can be easily selected even when the directivity of the antenna is complicated by burying an antenna for receiving a radio wave. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an aircraft position detection device according to a preferred embodiment of the present invention.

FIG. 2 is a structural diagram (longitudinal sectional view) of the aircraft position detecting device shown in FIG.

FIG. 3 is a structural view of the aircraft position detecting device shown in FIG. 2 as viewed from above.

4 is a diagram showing a relationship between an azimuth angle and an elevation angle of a GPS satellite used for detecting a moving object in the aircraft position detection device shown in FIG.

FIG. 5 is a configuration diagram of a moving object presence / absence determining unit 8 shown in FIG. 1;

FIG. 6 is a configuration diagram of a moving object arrival detection unit 52a shown in FIG. 5;

7 is a configuration diagram of a moving body detachment detection unit 53a shown in FIG.

FIG. 8 is a configuration diagram of a reception intensity decrease detection unit 62 shown in FIG. 6;

9 is a configuration diagram of a satellite data use evaluation unit 63 shown in FIG.

FIG. 10 is a configuration diagram of a reception strength increase detection unit 72 shown in FIG. 7;

11 is a configuration diagram of a moving object arrival determination unit 54 shown in FIG.

12 is a diagram showing a relationship between output data output from the moving object arrival detection unit 52a shown in FIG. 5 and the meaning of the data.

13 is a configuration diagram of a moving body separation determination unit 55 shown in FIG.

14 is a diagram illustrating a relationship between output data output from the moving body separation detecting unit 53a illustrated in FIG. 5 and the meaning of the data.

15 is a configuration diagram of a moving object presence detection unit 56 shown in FIG.

FIG. 16 is a configuration diagram of the information integration unit 11 shown in FIG.

17 is a configuration diagram of a moving object type determination unit 163 shown in FIG.

18 is a diagram showing a relationship between output data output from the moving object type determination unit 163 shown in FIG. 17 and the meaning of the data.

19 is a diagram showing a display example on the detection result display section 12 shown in FIG.

[Explanation of symbols]

1 ... AC power supply, 2 ... Power line, 3a-3n ... Transformer, 4
a to 4n: Moving object detector, 5a to 5n: Lamp, 6: Antenna, 7: Receiving unit, 8: Moving object presence / absence determining unit, 9: Information transmitting unit, 10: AC / DC converter, 11: Information integrating unit , 12 ... Detection result display section.

Continued on the front page (72) Inventor Juichiro Atsumi 5-2-1 Omikacho, Hitachi City, Ibaraki Prefecture F-term in the Hitachi, Ltd. Omika Plant F-term (reference) 2G005 DA02 5J062 BB03 CC07

Claims (9)

[Claims] An antenna for receiving radio waves transmitted from a plurality of GPS satellites, receiving means for extracting a radio wave reception intensity and an elevation angle of a GPS satellite from information contained in the radio waves received by the antenna, and the reception intensity And a mobile object that selects a GPS satellite to be used for detecting the mobile object from the plurality of GPS satellites based on the elevation angle, and detects the mobile object based on a change in reception intensity of a radio wave transmitted by the selected GPS satellite. A moving object detection device comprising: presence / absence determination means. 2. The mobile object presence / absence determining means includes a mobile object arrival determining means for determining that a mobile object has come above the antenna, and wherein the mobile object arrival determining means includes the selected G.
2. The moving object detection device according to claim 1, wherein it is determined that the moving object has come above the antenna based on a decrease in the reception intensity of the radio wave transmitted by the PS satellite. 3. The moving object presence / absence determining means detects a GPS satellite whose elevation angle is smaller than a first set value or whose radio wave reception intensity is lower than a second set value even though no moving object exists above the antenna. 3. The moving object detecting device according to claim 1, further comprising a unit that determines that the moving object is not used for detecting a moving object. 4. The moving object presence / absence determining means includes moving object leaving determination means for determining that the moving object has left from above the antenna. 4. The moving object detection device according to claim 1, wherein it is determined that the moving object has left from above the antenna based on an increase in the reception intensity of the transmitted radio wave. 5. The moving object detection device according to claim 1, wherein the antenna is buried under the ground. 6. A plurality of moving object detection devices arranged on a route on which an aircraft travels, and aircraft position detection for detecting a position of the aircraft on the route based on a result of detection of a moving object by the plurality of moving object detection devices. An aircraft position detecting device comprising: means for detecting a moving object, wherein the moving object detecting device is the moving object detecting device according to any one of claims 1 to 5. 7. The aircraft position detecting device according to claim 6, further comprising a power line for transmitting detection results of said plurality of moving object detecting devices to said aircraft position detecting means. 8. The aircraft position detecting means, wherein when a plurality of adjacent moving object detecting devices detect a moving object, the positions of the plurality of adjacent moving object detecting devices are set as positions of the aircraft. The aircraft position detecting device according to any one of claims 6 and 7. 9. The aircraft detection device according to claim 8, further comprising display means for displaying a position of the aircraft on the route based on a detection result by the aircraft position detection means.