JP3522256B2 - Surface condition detection method, surface condition detection system, and surface condition detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground condition detecting method, a ground condition detecting system, and a ground condition detecting apparatus suitable for detecting the condition of the ground surface, particularly the ground surface of a runway where an aircraft takes off and landing.

[0002]

2. Description of the Related Art Aircraft accidents can lead to a great human disaster and must be prevented in advance. By the way, on the runway, objects such as structural materials, panels, and rods (hereinafter, FO: Foreign Obje
ct), and pavement cracks, depressions, and bumps on the runway may be present. Such FOs, pavement cracks, depressions, and ridges, as well as wet and frozen conditions on the ground surface (hereinafter referred to as ground conditions) are one of the causes of an aircraft accident. Therefore, in order to ensure a high degree of safety in the operation of aircraft, it is essential to check the surface condition and remove FO and repair pavement cracks. Therefore, conventionally, an inspector has walked or boarded a low-speed vehicle and patrolled the runway to visually check the surface condition of the inspector.

[0003]

However, when an inspector makes a walk or walks by a low-speed vehicle, it takes a considerable amount of time to finish the entire runway patrol. Therefore,
When the frequency of departures and arrivals of aircraft is high, it is necessary to shorten the patrol time and carry out before departure and arrival. In addition, since the runway is generally several kilometers long and has a vast area,
The mental fatigue of the inspector due to the patrol work is also great. Therefore, the work efficiency may be deteriorated and the FO may be overlooked.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to obtain the ground surface conditions such as FO, pavement cracks, depressions, bumps, wet conditions, and frozen conditions regardless of the weather, and Especially on the runway, regardless of whether the aircraft is taking off or landing, it can be detected relatively reliably and efficiently, and the surface condition detection method that can reduce the work by the inspector,
An object of the present invention is to provide a surface condition detecting system and a surface condition detecting device.

[0005]

According to the present invention described above, a signal wave is transmitted toward a surface area, the signal wave reflected by an object existing in the surface area is received, and the signal wave is transmitted. The distance to the object is calculated based on the time from the reception to the reception or the phase difference between the transmitted signal wave and the received signal wave. In addition, short-wavelength light is detected to image the surface area. Further, the ground condition is detected based on the information indicating the calculated distance and the information indicating the captured image.

For example, a distance calculation device such as a laser radar or a radio wave radar calculates a distance to an object existing in the ground surface area, and an image pickup device such as an ultraviolet image sensor detects ultraviolet rays in the ground surface area to pick up an image. , The ground state is detected based on the information on the distance and the information on the image.

In this case, from the information indicating the distance obtained by using the laser radar, F having a predetermined size is obtained.
O, the pavement cracking, depression, upheaval, etc. can detect the surface condition of the ground. On the other hand, from the information showing the image acquired using the ultraviolet image sensor, the reflectance of light is larger than that of the ground surface. For example, if the size is smaller than the specified size, it is relatively small
It is possible to detect an FO, a planar FO such as a panel, a wet condition and a frozen condition of the ground surface, which are difficult to detect by the laser radar. In particular, on the runway, almost all the ground surface conditions necessary for safe operation of the aircraft can be detected with almost no influence of departure / arrival of the aircraft, weather, or the like.

Further, the present invention described above further includes a surface condition detecting device for collecting the information indicating the distance and the information indicating the image and detecting the surface condition.

Therefore, the information indicating the distance and the information indicating the image are unified at a place separated from the surface of the runway or the like to be inspected (for example, a management center responsible for the inspection work of the runway). In addition to being able to manage the information and checking it by personnel, it is possible to send information to the control center provided at the airport and use this information for safe operation of the aircraft.

The above-described invention detects light having a wavelength in the range of 190 nm to 500 nm as short wavelength light.

When light having a wavelength within the above range is detected and imaged, FO or the like having a light reflectance higher than that of the surface of the earth is compared with that in the visible light regardless of the position of the sun and the image pickup position. The image can be more clearly captured, and the detection accuracy of the ground condition can be further improved. Also, within the range of 190 nm to 500 nm, 280 nm to 315 nm
It is more desirable to detect and image UVB, which is light whose wavelength is included in the range, in order to improve detection accuracy.

Further, according to the present invention described above, binarization processing and noise removal processing are performed on the image picked up by the image pickup device.

Therefore, the ground surface condition can be detected more accurately.

Further, in the above-mentioned present invention, the distance calculation device and the image pickup device are installed in the vicinity of the runway in order to detect the ground condition of the runway where the aircraft takes off and landing.

Therefore, for example, by installing a plurality along the runway, the ground surface condition of the runway can be efficiently and early detected regardless of the departure and arrival of the aircraft, and the safety of the operation of the aircraft can be further improved. Can be improved.

Further, according to the present invention described above, the distance calculating device is of a self-propelled type, and is installed so as to be movable along the runway.

Therefore, it is possible to reduce the investment cost for the equipment necessary for detecting the ground condition of the entire runway having a vast area.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic diagram showing an arrangement configuration of equipment when the surface condition detection system according to the present invention is applied to a runway. In the figure, 1 is a runway provided at an airport, and a pair of laser radars 2 and 2 facing each other with the runway 1 in between are installed. A plurality of pairs of the laser radars 2 and 2 are arranged at predetermined intervals along the longitudinal direction of the runway 1.

Further, a plurality of ultraviolet image sensors 3 are installed on both sides of the runway 1 at predetermined intervals along the longitudinal direction of the runway 1 and alternately on both sides of the runway 1. Has been done.

On the other hand, on the premises of the airport having the runway 1, there is provided an information management center 4 capable of wirelessly or wiredly communicating with the laser radar 2 and the ultraviolet image sensor 3. The information management center 4 is equipped with the surface state detecting device 40 according to the present invention. Also,
A control center 5 that manages the operation of the aircraft is provided on the premises of the airport, and the control center 5 can communicate with the information management center 4.

FIG. 2 is a schematic diagram showing an example of a more detailed arrangement of the laser radar 2. As described above, the laser radars 2 are installed so as to face each other with the runway 1 in between, and the pair of laser radars 2 and 2 facing each other are arranged from the width center position of the runway 1 as shown in FIG. Only 150m apart. The laser radars 2 and 2 adjacent to each other in the longitudinal direction of the runway 1 are separated by 520 m.
Further, the installation height of the laser radar 2 is 0.2 m or more above the ground, but the laser radar 2 may be configured to be vertically expandable / contractible as necessary.

The laser radar 2 according to this embodiment is
It is possible to calculate the distance to an object existing in the ground surface area, and calculate the distance for the object existing in the fan-shaped surface area 2a having a radius of 300 m and a central angle of 120 ° centered on its own installation position. set to target. In this case, the range in the longitudinal direction of the runway 1 in the ground surface areas 2a, 2a targeted by the opposing laser radars 2, 2 is 520 m.

By the way, the runway 1 usually has the highest altitude at the width center position and is inclined downward from the width center position toward both sides. FIG. 3 is a cross-sectional view of the runway 1, and as shown in the figure, when the installation height of the laser radar 2 is relatively low, the target surface area 2 a is divided at the width center position of the runway 1. Therefore, as shown in FIG.
By disposing the radar 2, the pair of opposing laser radars 2 and 2 can include the entire range of the runway 1 in the longitudinal direction 520 m in the ground surface area 2 a. In addition, the laser radars 2 and 2 adjacent to each other in the longitudinal direction of the runway 520
Since they are installed at m intervals, the entire length of the runway 1 can be covered.

The arrangement form of the laser radar 2 as described above is an example, and other installation forms can be appropriately adopted depending on the performance of the laser radar 2 and the environmental conditions. Further, it goes without saying that the laser radar 2 may be replaced by another device such as a radio wave radar or an ultrasonic radar that can measure the distance by using the wave propagating in space. Further, when arranged as described above, eight pairs of laser radars 2 are required on the 4000 m class runway, which is the largest scale in Japan.

FIG. 4 is a schematic diagram showing an example of a more detailed arrangement configuration of the ultraviolet image sensor 3. UV image sensor 3
Is 500 from the width center position of the runway 1 as shown in FIG.
They are separated by m and are installed every 520 m in the longitudinal direction of the runway 1. The installation height of the ultraviolet image sensor 3 is based on 50 m above the ground.

The ultraviolet image sensor 3 according to this embodiment is
It detects light included in the wavelength range of 190 nm to 500 nm (hereinafter referred to as short-wavelength light) to image the surface area, and has a radius of 5 with respect to its own installation position.
The fan-shaped ground surface area 3a having a center angle of 58 ° at 90 m is targeted.

In this case, the range in the longitudinal direction of the runway 1 in the surface area 3a targeted by the ultraviolet image sensor 3 is 52.
Since the installation height is 0 m and the installation height is relatively high at 50 m above the ground, one range of the runway 1 in the width direction can be covered by one ultraviolet image sensor 3. Further, since the ultraviolet image sensor 3 and the ground surface region 3a are relatively separated from each other, the ultraviolet image sensor 3 according to the present embodiment has a relatively narrow viewing angle (for example, a wide viewing angle) in order to improve the resolution of an image to be captured. , 1.26 ° (V) * 0.47 ° (H) etc.)
The ultraviolet image sensor 3 is used to image the entire ground surface area 3a by appropriately changing the imaging direction.

The arrangement form of the ultraviolet image sensor 3 as described above is an example, and other installation forms can be appropriately adopted depending on the performance of the ultraviolet image sensor 3, environmental conditions and the like. Further, when arranged in this way, eight ultraviolet image sensors 3 are required on a 4000 m class runway.

Next, the configuration of each device used in the surface condition detecting system according to the present embodiment will be described. In addition,
The ultraviolet image sensor 3 detects short-wavelength light using a high-sensitivity CCD or the like and converts an optical signal into an electric signal. Since it can be realized by using a known one, detailed description thereof will be given here. Omit it.

FIG. 5 is a block diagram showing the configuration of the laser radar 2. Reference numeral 20 in the figure denotes a light source, which can emit laser light. The laser light emitted from the light source 20 is split into laser light in two directions by the beam splitter 21. One of the split laser beams (hereinafter referred to as the first laser beam) is the analyzer 2
Input to 5. The other laser beam is incident on one mirror surface of an inverted V-shaped mirror body 22 having two mirror surfaces whose normal directions are substantially orthogonal to each other. The incident laser light is reflected by the one mirror surface, is output to the outside of the laser radar 2, and is irradiated on the object existing in the ground surface area 2a.

The mirror body 22 is provided with a motor 23, and the mirror body 22 is driven so that the direction of the mirror surface changes when the motor 23 drives. That is, the operation of the motor 23 is controlled by the CPU 26 described later, and the mirror body 22 is moved so that the first laser light emitted from the laser radar 2 scans the ground surface area 2a shown in FIGS. Drive it.

More specifically, the scanning method will be described. First, after scanning the horizontal direction by 120 °, the depression angle of the laser radar 2 is lowered by a predetermined angle and then again by 120 ° in the horizontal direction.
Just scan. As shown in FIG. 2, in order for the laser radar 2 to scan the entire range of the ground surface area 2a, it is necessary to scan the range of 0.15 ° in the vertical direction. Therefore, by repeating the operation as described above, the laser radar 2 completes the scanning of the entire range of the ground surface area 2a only once when the cumulative angle of the depression angle gradually decreased to 0.15 ° or more. It has been done. In this way, when the cumulative depression angle is 0.15 ° or more, the reverse operation is performed in which the depression angle of the laser radar 2 is sequentially increased by a predetermined angle after the horizontal scanning of 120 °. Also, when the cumulative angle of depression is 0.15 ° or more,
It is also possible to return the direction of the laser radar 2 to the initial depression angle, scan again in the horizontal direction, and then lower the depression angle by a predetermined angle.

The predetermined angle may be, for example, a value obtained by dividing the total change angle of the depression angle of 0.15 ° into 20. In this case, runway 1 included in surface area 2a
In the above, assuming that the difference between the highest point and the lowest point is 40 cm, the laser radar 2 theoretically has a resolution capable of detecting an FO having a height of about 2 cm.

Further, by dividing the total change angle of the depression angle of 0.15 ° into finer divisions (for example, 100 divisions), the laser radar 2 can have a higher resolution, but the processing time is long. However, the number of divisions may be determined in consideration of these circumstances.

Next, a part or all of the laser light reflected by the object is input to the mirror body 22 and is incident on the other mirror surface. The incident laser light is reflected by the other mirror surface and is input to the filter 24. The light reflected by the other mirror surface of the mirror body 22 and input to the filter 24 includes not only laser light but also light having various wavelengths such as visible light and infrared light. Only light having the same wavelength as the first laser light is extracted from among them. The extracted light (hereinafter referred to as the second laser light) is
Input from the filter 24 to the analyzer 25.

The analyzer 25 includes a beam splitter 21.
The first laser light directly input from the CPU and the second laser light input through the filter 24 are analyzed to generate digital data regarding amplitude and phase, and the CPU
26.

The CPU 26 controls the operation of the hardware constituting the laser radar 2 and also calculates the distance to the object and the average value of the distance based on the data input from the analyzer 25. The data obtained by performing the communication is transferred to a communication interface such as a modem (hereinafter, communication I /
It is transmitted to the information management center 4 via the antenna connected to the (F) 27.

FIG. 6 is a block diagram showing the configuration of the ground surface state detecting device 40 according to this embodiment. The ground surface state detection device 40 includes a CPU 41, and the CPU 41 is a RAM.
42, ROM 43, hard disk (hereinafter, HD) 44, and communication interface (hereinafter, communication I /
45), etc., is controlled.

The RAM 42 temporarily stores the data generated while the CPU 41 performs the arithmetic processing, and also temporarily stores the data transmitted and received through the communication I / F 45. The ROM 43 is composed of a PROM, a mask ROM, etc., and basic computer programs necessary for operating the ground surface state detecting device 40 according to the present embodiment are stored in advance.

The HD 44 is the ROM 4 necessary for operating the ground surface state detecting device 40 according to the present embodiment.
A computer program different from the one stored in 3 is stored. Further, the data received via the communication I / F 45 is stored in a database format. The communication I / F 45 is hardware for communicating with the laser radar 2, the ultraviolet image sensor 3, and the control center 5 via an antenna.

The configurations of the laser radar 2 and the ground surface state detecting device 40 shown in FIGS. 5 and 6 are examples.
Other configurations can be adopted as appropriate.

Next, the CPU 2 provided in the laser radar 2
The operation flow of No. 6 will be described with reference to the flowchart shown in FIG. As described above, the analyzer 25 outputs digital data regarding the amplitude and phase of the first laser light and the second laser light, and the CPU 26 receives the digital data (S1). The CPU 26 determines the time lag (that is,
The distance to the object is calculated by calculating the phase difference between the first laser light and the second laser light (S2).

FIG. 8 is a chart schematically showing an example of the calculation result for explaining the contents of the calculation processing in the CPU 26. Of these, FIG. 8A is a chart showing the relationship between the scanning angle of the laser light and the distance to the object calculated in step 2. As shown in the figure, in this case, the distance calculated during the scan angle from X to Y is longer than the distance calculated during the other scan angles.

By the way, when the laser radar 2 scans the ground surface area where the FO exists and the distance is calculated, the distance from the laser radar 2 becomes short only where the FO exists. On the other hand, when the distance is calculated by scanning the ground surface area where the pavement crack exists with the laser / laser 2, the distance from the laser radar 2 increases only where the pavement crack exists. Therefore, in the case of FIG. 8A, it can be understood that pavement cracks may exist between the scanning angles X and Y.

The CPU 26 differentiates the function indicating the distance calculated in step 2 with the scanning angle as a parameter (S3). FIG. 8B is a chart showing a result obtained by differentiating the calculation result shown in FIG. 8A by the scanning angle. As shown in FIG. 8A, the distance to the object becomes long at the scanning angle X, and the distance to the object becomes short at the scanning angle Y. Therefore, as shown in FIG. 8B, the result of differentiation with respect to the scan angle (that is, the degree of change in distance with respect to the scan angle) has a predetermined positive value at the scan angle X and a predetermined value at the scan angle Y. It has a negative value. By extracting the degree of change in the distance in this way, edge locations such as FO or pavement cracks (scan angles X and Y in FIG. 8)
Can be extracted.

Next, the CPU 26 sets the ground area 2a in a plurality of ranges (in FIG. 8, the scanning angle is X or less and the scanning angle is X) based on the scanning angle values X and Y obtained as a result of the differential processing in step 3. To Y and three ranges in which the scanning angle is Y or more), and the average value of the distances calculated in step 2 is calculated in each range (S4). FIG. 8C shows
9 is a chart showing the relationship between the distance calculated in step 4 and the scanning angle.

Further, the CPU 26 transmits the data regarding the average value of the distance calculated in step 4 to the information management center 4 (S5), and the transmitted data regarding the average value of the distance is calculated from the scanning angle X as described later. It is used to judge whether pavement cracks exist in the range up to Y. Further, the laser radar 2 irradiates the laser light from the light source 20 at a predetermined cycle. Therefore, the CPU 2 shown in steps 1 to 5 above
The operation of 6 is repeated every time data is received from the analyzer 25 in the predetermined cycle.

Next, based on the data relating to the average value of the distances collected from the laser radar 2, the surface condition detecting device 4
The flow of operation when the CPU 41 provided in 0 determines whether there is an FO or pavement crack will be described with reference to the flowchart shown in FIG. The surface condition detecting device 40
Collects data from each of the plurality of laser radars 2, the following operation is performed by time-division processing, or when the ground surface state detecting device 40 has a plurality of CPUs, the processing is divided by each CPU. To do.

First, when the data concerning the average value of the distance is received from the laser radar 2 (S10), the CPU 4
1 compares the average value of the distances indicated by the received data with a predetermined threshold value (hereinafter referred to as the first threshold value) (S11),
The size relationship is judged (S12).

The first threshold value is a numerical value that depends on the accuracy of distance calculation by the laser radar 2 and environmental conditions such as weather. By comparing the average value of the distance and the first threshold value, the FO Alternatively, the presence of pavement cracks can be determined.

FIG. 10 is a table showing an example of the relationship between the average value of distances and the first threshold value. When the distance to the ground surface area where FO and pavement cracks do not exist is set to L, L + α and L−α are set as the first threshold in consideration of the detection error of the laser radar 2. Of these, L + α is a threshold value for detecting pavement cracks, and L−α is a threshold value for detecting FO.

Therefore, the average value of the calculated distances is L + α
And in the range of L-α, both FO and pavement cracks do not exist in the ground surface area, and it can be determined that the area is normal. On the other hand, the average value of the calculated distances is L + W, and L + W
When W> L + α, it can be determined that pavement cracking exists, and when the calculated average distance is L−H, and L−H <L−α, FO exists. Then you can tell.

For example, the average value of the distances obtained in the range of the scanning angle X or less shown in FIG. 8C is within the range of the first threshold value, that is, between L + α and L-α, Similarly, the average value of the distances obtained in the range of the scanning angle Y or more is the first value.
If the average value of the distances obtained in the range of the scanning angles X to Y is outside the range of the first threshold, that is, L + α or more or L-α or less, the scanning is performed. It is determined that FO or pavement crack (here, pavement crack) exists in the range between the angles X and Y.

When it is determined in step 12 that the average value of the distances does not exceed the first threshold value (S12: YES), it is determined that there is no FO or the like in the surface area 2a (S13),
The system waits for data reception from the laser radar 2 again and repeats the operation from step 10. Also, step 12
When it is determined that the average value of the distances exceeds the first threshold value (S12: NO), it is determined that the FO or the like exists in the ground surface area 2a (S14), and the result is output to the monitor or printed on the paper. In addition to outputting (S15), the control center 5 can also be provided with information indicating the surface condition of the runway 1.
After the output in step 15, the operation after step 10 is repeated again.

FIG. 11 is a chart schematically showing another example of the calculation result in the CPU 26. In addition, FIG.
Is a chart showing the relationship between the scanning angle of the laser beam and the calculated distance to the object, and FIG. 11 (b) shows the result obtained by differentiating the calculation result shown in FIG. 11 (a) by the scanning angle. FIG. 11C is a chart showing the relationship between the calculated average value of the distance and the scanning angle.

In the case as shown in FIG.
Unlike the case shown in (a), the distance calculated during the scanning angle from X to Y is shorter than the distance calculated during the other scanning angles. Therefore, it is understood that FO may exist between the scanning angles X and Y.

Therefore, when the differentiation process shown in step 3 of FIG. 7 is applied to the result shown in FIG. 11A, a predetermined negative value is obtained at the scanning angle X as shown in FIG. 11B. It is found that the scanning angle Y has a predetermined positive value, and the edge portion of FO can be extracted. Further, by calculating the average value of the distances as shown in step 4 in each range divided by the edge portion,
The calculation result as shown in (c) can be obtained.

Further, based on the data showing the obtained calculation result, the measuring means control unit 10 performs the processing as shown in the flowchart of FIG. 9 so that FO exists between the scanning angles X and Y. It is possible to determine whether or not.

As described above, using the laser radar 2,
The surface condition can be detected for the presence or absence of both FO and pavement cracking.

The method of detecting the surface condition by the laser radar 2 described above is an example, and the step 1 shown in FIG.
9 to the operation of step 5 and the operation of step 11 to step 14 shown in FIG. 9 are all performed by the CPU 26 included in the laser radar 2, and only the result of the determination of the presence or absence of FO and the like obtained as a result is transmitted to the information management center 4. You may do it. Further, the analyzer 25 provided in the laser radar 2
The data output from the device is transmitted to the information management center 4 through the communication line, and the operations of steps 2 to 5 shown in FIG. 7 and the operations of steps 11 to 15 shown in FIG. CPU 41 included in 40
May be performed in. In this way, the operation performed by the laser radar 2 and the operation performed by the ground surface state detecting device 40 may be appropriately shared.

Next, a case where the ground surface state is detected based on the image of the ground surface area 3a taken by the ultraviolet image sensor 3 will be described.

First, the principle of capturing an image of the ground surface area 3a by the ultraviolet image sensor 3 detecting short wavelength light will be described. In the outdoor environment, there are mainly two types of light that illuminate the surface area 3a. That is, there are direct light emitted directly from the sun and skylight emitted from the entire sky as a surface light source by scattering the light emitted from the sun in the atmosphere. Therefore, the object such as FO existing in the surface area 3a and the ground surface reflect both the direct light and the skylight, and are incident on the image sensor such as the visible light image sensor and the ultraviolet image sensor 3.

By the way, when the sun and the image sensor are in a regular reflection positional relationship with respect to the FO, visible light and short light are reflected unless the reflectance of the FO is sufficiently smaller than the reflectance of the ground surface. In any case of the wavelength light, the FO is detected brighter than the ground surface. However, it is rare that the sun and the image sensor have the above-mentioned regular reflection positional relationship, and there is usually a high probability that the sun and the image sensor do not have the regular reflection positional relationship.

On the other hand, when the sun and the image sensor are not in the position of regular reflection with respect to FO, in the ultraviolet light, the sky light component incident on the image sensor is about 1.5 times the direct light component. On the other hand, with visible light, the sky light component is only about 1/9 times the direct light component even on a sunny day. This is because ultraviolet light has a shorter wavelength than visible light and is scattered more in the atmosphere to have more skylight components.

That is, when the sun and the image sensor are not in the positional relationship of regular reflection, the visible light image sensor mainly detects strong direct light from the ground surface and detects it, and weak sky light is reflected from FO. The FO is imaged relatively bright only when it has a reflectance sufficiently higher than the ground surface. On the other hand, in the ultraviolet image sensor 3, the main component of the incident light is the skylight, and if the reflectance of FO is slightly higher than that of the ground surface, the FO is compared even if it is not in the positional relationship of the regular reflection. It is captured brightly.

As described above, by using the ultraviolet image sensor 3 instead of the visible light image sensor, the positional relationship between the sun and the image sensor (backlight position, forward light position) or the weather condition (clear weather, cloudy weather) is taken into consideration. If the reflectance of FO is larger than that of the ground surface, the FO can be brightly imaged. The ultraviolet image sensor 3 is a laser radar 2
Since it has a feature of higher resolution, it is possible to image a relatively small FO such as a bolt or the like, and a planar FO such as a panel or the like, in distinction from a normal ground surface. In addition, when the ground surface is wet due to rainfall, even if it is frozen, the reflectance is generally higher than that of a normal ground surface. Can be imaged separately from the normal ground surface.

Further, since an ultraviolet image (an image obtained by detecting ultraviolet light) is taken and visible light is not used, even if FO has the same color as the ground surface, the FO is distinguished from the ground surface and taken. be able to. Further, since infrared rays are not used, the FO can be distinguished from the ground surface and imaged even when there is almost no temperature difference between the FO and the ground surface.

Next, the flow of operation when the CPU 41 provided in the ground surface state detecting device 40 judges the presence or absence of FO etc. based on the data relating to the image collected from the ultraviolet image sensor 3 is shown in the flowchart of FIG. Will be explained.

First, the CPU 41 receives data relating to an image from the ultraviolet image sensor 3 (S20), and sets the brightness value of each pixel indicated by the received data and a predetermined threshold value (hereinafter referred to as the second threshold value). Binarization processing is performed by comparison (S21). FIG. 13 is a schematic diagram for explaining the process in the CPU 41 based on the data related to the image received from the ultraviolet image sensor 3, and FIG. 13A is a schematic diagram showing the image before the binarization process. FIG. 13B is a schematic diagram showing the image after the binarization process. As shown in FIG. 13A, the image obtained by the ultraviolet image sensor 3 contains an image considered to be an FO and some noise, and has a shaded background due to uneven brightness. However, by performing the binarization process in step 21, a black and white image is obtained as shown in FIG.

The CPU 41 removes the noise by subjecting the image obtained by the processing in step 21 to the black area contraction processing and the black area expansion processing (S22). Further, the area of the image considered to be FO or the like is extracted by performing labeling on the image from which noise has been removed (S23). FIG. 13C is a schematic diagram showing an image obtained after the image shown in FIG. 13B has been subjected to contraction / expansion processing and area extraction.

Next, the size relation between the area extracted in step 23 and a predetermined threshold value (hereinafter referred to as a third threshold value) is determined (S24). The third threshold value is a numerical value that slightly depends on the resolution of the image captured by the ultraviolet image sensor 3, environmental conditions, etc. When the extraction area is equal to or greater than the third threshold value, the ultraviolet image sensor 3 captures an image. The possibility that FO and the like exist in the ground surface area 3a is relatively high, and when the extraction area is smaller than the third threshold value, the possibility that the FO and the like exist is relatively small.

When it is determined in step 24 that the extraction area is smaller than the third threshold value (S24: YES), the surface area 3
It is determined that FO does not exist in a (S25). Then, in order to follow changes in the environment,
The value of the second threshold value used for the binarization process is updated, and the operations of step 20 and subsequent steps are repeated again.

On the other hand, when it is determined in step 24 that the extraction area is equal to or larger than the third threshold value (S24: NO), it is determined that FO or the like exists in the surface area 3a (S27), and the result is displayed on the monitor or In addition to printing output on paper (S2
8) It is also possible to provide the control center 5 with information indicating the surface condition of the runway 1. After the output in step 28, the operation after step 20 is repeated again.

The method of detecting the surface condition by the surface condition detecting device 40 described above is an example, and the ultraviolet image sensor 3 is used.
The CPU is equipped with a CPU, and the CPU performs all the operations of steps 21 to 27 shown in FIG.
May be transmitted to. In this way, the operation performed by the ultraviolet image sensor 3 and the operation performed by the ground surface state detection device 40 may be appropriately shared.

As described above, the surface condition detecting device 40 is
The ground condition is detected by using the data obtained by the laser radar 2 and the ultraviolet image sensor 3, respectively. In particular,
Both the laser radar 2 and the ultraviolet image sensor 3 are constantly operated regardless of the departure and arrival of the aircraft, and the ground surface conditions such as the presence of relatively large FO, pavement cracks, depressions, and ridges are collected from the laser radar 2. Based on the data collected from the ultraviolet image sensor 3, ground surface conditions such as a relatively small FO, the presence or absence of a planar FO, a wet condition, and a frozen condition are detected.

Furthermore, if it is found as a result of the detection that FO or the like is present, it is displayed on a monitor or printed out on paper, and other than that, an alarm lamp and voice are used to notify, and control is also provided. You may make it report to the center 5.

As described above, according to the ground condition detecting system of the present embodiment, the laser radar 2 and the ultraviolet image sensor 3 are installed, and the information indicating the distance obtained from the laser radar 2 and the ultraviolet light are obtained. The state of the target ground surface is detected based on the information indicating the image obtained from the image sensor 3. According to the laser radar 2, a relatively large FO of about 10 cm or more, a pavement crack, etc., even if these have the same reflectance as the ground surface (that is, regardless of the reflectance)
It can be detected, and according to the ultraviolet image sensor 3, 10
It is possible to detect a relatively small FO of about cm or less, a flat FO such as a panel, a wet state and a frozen state of the ground surface, and a FO having a reflectance higher than the ground surface. Therefore, the ground condition can be detected in detail and accurately.

Since the ground condition detecting device 40 for collecting data from the laser radar 2 and the ultraviolet image sensor 3 is provided, the ground condition detecting device 40 can centrally manage the data and collect the collected data. The surface condition can be detected based on the.

Since the image picked up by the ultraviolet image sensor 3 is subjected to binarization processing and noise removal processing,
The ground condition can be detected more accurately.

Further, since the laser radar 2 and the ultraviolet image sensor 3 are arranged in the vicinity of the runway 1, the ground condition of the runway 1 can be detected efficiently and early regardless of whether the aircraft is taking off or landing or regardless of personnel. Therefore, it is possible to improve the safety of the operation of the aircraft.

The laser radar 2 according to the present embodiment may be of a self-propelled type so that it can move along a track or an arbitrary route attached along the runway 1. In this case, It is possible to reduce the number of laser radars 2 required to detect the surface condition of the vast runway 1, and it is possible to reduce the equipment cost. The same applies to the ultraviolet image sensor 3.

Further, although the present embodiment describes the case of targeting a runway, it is needless to say that it is also effective in detecting the surface condition of a highway and other road surfaces.

[0083]

According to the present invention, FO, pavement cracking, depression,
Surface conditions such as upheaval, wet condition, and frozen condition can be detected relatively reliably and efficiently regardless of weather conditions and on the runway regardless of whether the aircraft is taking off or landing.
It is possible to provide a surface condition detecting method, a surface condition detecting system, and a surface condition detecting device that can reduce the work of an inspector.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an arrangement configuration of equipment when a surface condition detecting system according to the present invention is applied to a runway.

FIG. 2 is a schematic diagram showing an example of a more detailed arrangement configuration of a laser radar.

FIG. 3 is a cross-sectional view of the runway.

FIG. 4 is a schematic diagram showing an example of a more detailed arrangement configuration of an ultraviolet image sensor.

FIG. 5 is a block diagram showing a configuration of a laser radar.

FIG. 6 is a block diagram showing a configuration of a ground surface state detecting device according to the present embodiment.

FIG. 7 is a flowchart for explaining a flow of operations of a CPU included in the laser radar.

FIG. 8 is a chart schematically showing an example of a calculation result for explaining the contents of a calculation process in a CPU included in the laser radar.

FIG. 9 is a flowchart for explaining a flow of operations when a CPU included in the ground surface state detecting device determines whether or not there is an FO or a pavement crack.

FIG. 10 is a chart showing an example of a relationship between an average value of distances and a first threshold value.

FIG. 11 is a chart schematically showing another example of the calculation result by the CPU included in the laser radar.

FIG. 12 is a flowchart for explaining a flow of an operation when a CPU included in the ground surface state detecting device determines the presence or absence of an FO or the like.

FIG. 13 is a schematic diagram for explaining processing in a CPU based on data regarding an image received from an ultraviolet image sensor.

[Explanation of symbols]

1 runway 2 Laser radar (distance calculator) 3 Ultraviolet image sensor (imaging device) 4 Information management center 5 control center 20 light sources 21 Beam splitter 22 Mirror 23 motor 24 filters 25 analyzer 26,41 CPU 27,45 Communication interface (communication I / F) 40 Surface condition detector 42 RAM 43 ROM 44 hard disk (HD)

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Claims (10)

(57) [Claims] 1. A signal wave is transmitted to a ground surface area, the signal wave reflected by an object existing in the ground surface area is received, and the time from the transmission of the signal wave to the reception is transmitted. calculating a distance to the object based on the phase difference between the signal wave and the received signal wave, and images the surface area by detecting the short-wavelength light in sunlight which wavelength is in the range from 190 nm ~ 500 nm , Based on the information indicating the calculated distance and the information indicating the captured image
At least the existence of the object in the state and the frozen state
A method of detecting a ground condition, comprising detecting a ground condition including the ground condition. 2. The surface state detecting method according to claim 1, wherein the short-wavelength light has a wavelength in the range of 280 nm to 315 nm . 3. A means for transmitting a signal wave toward the surface area, a means for receiving the signal wave reflected by an object existing in the surface area, and a time from transmission to reception of the signal wave, or, a distance calculating device having a means for calculating a distance to the object based on the phase difference between the transmitted signal wave and the received signal wave, short wavelength in sunlight which wavelength is in the range from 190 nm ~ 500 nm An image pickup device having means for picking up an image of the ground surface area by detecting light, and based on the information indicating the calculated distance and the imaged image, an object on the ground surface, a pavement crack, a depression, a ridge, Damp
Presence or absence of at least the object in the wet state and the frozen state
A surface condition detecting system comprising means for detecting a surface condition including the following . 4. The surface condition detecting device according to claim 3, further comprising a surface condition detecting device having a unit for collecting the information related to the distance and the information related to the image, and a unit for detecting the surface condition. Surface condition detection system. 5. The surface condition detecting system according to claim 3, wherein the short-wavelength light is light having a wavelength in the range of 280 nm to 315 nm . 6. The ground surface state detecting system according to claim 3, further comprising: a unit that performs a binarization process and a unit that performs a noise removal process on the image. 7. The surface condition is a surface condition of a runway where an aircraft takes off and landing, and the distance calculation device and the imaging device are installed in the vicinity of the runway. The surface condition detection system according to any one of 1. 8. The surface condition detecting system according to claim 7, wherein the distance calculating device is self-propelled and is installed so as to be movable along the runway. 9. Information relating to the distance to an object existing on the surface area, and the wavelength is included in the range of 190 nm to 500 nm.
Means for collecting each of the information indicating the image of the ground surface area that is detected by detecting short-wave light in the sunlight, and based on the collected information, objects on the ground surface, pavement cracks, depressions, bumps, wetting Condition
State and frozen state, including at least the presence or absence of the object.
An apparatus for detecting a ground surface condition, comprising: a unit for detecting a ground condition; and a unit for outputting information indicating the detected ground condition. 10. The short wavelength light has a wavelength 280nm ~ 315nm
10. The light included in the range of
The surface condition detection device described.