JP4938838B2 - Improved aircraft docking system - Google Patents

Description

  The present invention relates to an aircraft docking system installed at a docking site, the system comprising distance determining means configured to determine at least a distance between the system and the aircraft.

In recent years, there has been a growing need to streamline operations at airports, and at the same time there has been a need to use an automated aircraft docking system at many airports instead of manually leading an aircraft to a gate.
In general, the technology used by the automatic docking system is affected to some extent when visibility is deteriorated due to, for example, fog or rain. The expression “view” may be thought of as the permeability of electromagnetic radiation of an appropriate wavelength in the atmosphere. An example of such a system is disclosed in US Pat. No. 6,563,432. In this case, the system that detects and determines the distance to the aircraft scans the area at the gate with a laser pulse, analyzes the reflected laser pulse to detect solid objects, and also detects solid objects and fog or rain. To distinguish.
Another example of an automatic docking system that is affected by viewing conditions is disclosed in US Pat. No. 6,542,086. The system of US Pat. No. 6,542,086 uses a video camera as a sensor.
US Pat. No. 6,563,432 US Pat. No. 6,542,086

  The disadvantage of such a system is that it cannot always be docked in all climatic conditions, even when the airport is open and ready for use. The aircraft must be guided 80-100 meters away from the closest location (generally the gate) where the docking system is installed, while the airport can be opened and used even if the field of view is 80-100 meters or less. As a result, in conditions where automatic docking is not possible due to fog or rain, docking must be performed manually by the leader. The problem in such a situation is that it is not clear whether manual guidance is required until the aircraft approaches the gate and finds that the fog and rain are so heavy that it cannot be guided by the docking system. In large airports, this can happen at multiple gates at the same time, and this is not anticipated, causing confusion in the operation of the airport and associated problems such as cost or reduced safety There is.

  The system disclosed in US Pat. No. 6,563,432 detects, identifies and docks an aircraft and determines whether the detected object is solid, fog or rain, but does not determine whether automatic docking is possible .

  In general, visibility at an airport is measured using a visibility meter installed near the runway. However, the output of existing visibility meters generally does not represent the conditions in the docking system very well. This is because it is usually installed at a gate near the terminal building, and the fog density usually varies considerably throughout the airport. Also, installing such a visibility meter at each gate is not an optimal solution. The output of this meter still does not represent the conditions that govern the performance of the docking system. This is because fog is partly present and the operating area of the system extends about 100 meters away from the system. Another disadvantage of such a solution is that the cost is increased by installing a plurality of expensive view meters.

Because prior art systems have the disadvantages described above, there is a need in the field of aircraft docking systems that can determine whether docking is possible using this system at current viewing conditions.
Accordingly, it is an object of the present invention to provide a docking system that determines a viewing condition within the operating region of the system, and that provides a signal when docking using the system is not possible under this condition. That is.

  To achieve this object, a first aspect of the present invention provides an aircraft docking system configured to be installed at a docking site. The system includes distance determining means configured to determine at least the distance between the system and the aircraft using electromagnetic radiation signal receiving means. The distance determining means further measures at least one characteristic of the receiver signal received by the signal receiving means related to the field of view of the docking site, and is a measure of the at least one receiver signal characteristic. It is configured to compare to a threshold and, based on this comparison, provide a signal indicating whether the field of view at the docking site is good enough to allow safe docking using the system.

  In a second aspect, the present invention provides a method for controlling aircraft docking using an aircraft docking system installed at a docking site. The system includes distance determining means configured to determine at least a distance between the system and the aircraft using electromagnetic radiation signal receiving means, the distance determining means being a receiver signal received by the signal receiving means. And measuring at least one characteristic related to visibility at the docking site, comparing the measured value of the at least one receiver signal characteristic with a threshold, and based on the comparison Generating a signal indicating whether the field of view at the docking site is sufficiently good to enable safe docking using the system.

In a third aspect, the present invention provides a computer program comprising software instructions that when executed in a computer perform the method described above.
In a fourth aspect, the present invention provides for the use of an aircraft docking system that controls operation at an airport.

  In other words, the system according to the invention is configured to check the visibility conditions of the work area of the docking system before and / or during the docking of the aircraft. The system measures characteristics that relate to the visibility of the docking site and limit the performance of the system. The measurement result is used as a determinant for determining whether safe docking is possible under the visibility condition.

  Thus, the advantage of the present invention is that it provides airport operators with a high ability to determine whether docking operations can be performed when visibility is poor and it is uncertain whether safe docking is possible. is there. For example, prior art systems generally cannot distinguish between dense fog or rain and a portion of an approaching aircraft. Needless to say, this lack of ability to distinguish can lead to a dangerous situation. On the other hand, given the lack of such distinction capabilities, prior art systems only signal that docking is not possible when they are not sure. However, this means that the availability of the prior art system is not as high as the availability of the system according to the invention.

  Another advantage is that the air controller can be constantly given this information by constantly determining whether automatic docking is not possible due to fog or rain depth. Since it is possible to foresee the necessity of leading, the leading person can be put in place when the aircraft arrives, so that confusion due to docking delay can be prevented. Thus, for example, airport operations can be efficiently performed by reducing aircraft waiting time and quickly and efficiently allocating arriving aircraft to gates and terminals capable of automatic docking.

  A further advantage of the present invention is that by providing a solution to the above-mentioned problem, existing docking systems can be adapted to also provide signals representative of viewing conditions at the docking site. In general, this only requires changing the programming of the control software in the system. This means that the cost is much lower than when a separate viewing system is installed. There is no need to adapt existing docking system hardware. This is because the wavelength interval at which the docking system operates is also suitable for operations related to determining viewing conditions.

  Embodiments of the invention include aspects in which the distance determining means is configured to measure receiver signal characteristics related to the scattering of electromagnetic radiation. For example, the distance determining means may comprise laser distance measuring means, in which case the distance determining means may be configured to measure the scattering of the laser radiation. Alternatively, the distance determining means may comprise radar distance measuring means, in which case the distance determining means may be configured to measure radar radiation scatter. In another embodiment, backscattered electromagnetic radiation (more precisely, the power distribution of the backscattered radiation) indicates scattering.

  Another embodiment is an aspect in which the distance determining means comprises signal receiving means having image means configured to provide a two-dimensional image of the docking site, and the distance determining means is between at least two regions in the image. Configured to measure at least one characteristic of the receiver signal that is at least related to the contrast difference. These image areas may correspond to predetermined locations of the docking site, preferably the same distance from the system.

In other words, when the docking system uses two-dimensional image technology, the measure of visibility condition is the contrast in the image. By analyzing the image signal used to determine the position of the aircraft to determine the degradation of this signal caused by fog or rain, whether the degradation of visibility has exceeded a level where docking is unsafe or impossible A good indicator can be obtained.
The imaging means may be configured to detect electromagnetic radiation in either the visible wavelength interval and the infrared wavelength interval, and to detect electromagnetic radiation in both of these wavelength intervals.

  FIG. 1 shows a schematic view of an airport from above. Terminal 101 may be a passenger terminal and / or a cargo terminal and is configured to include a first aircraft docking system 115 and a second aircraft docking system 117. A first docking site 103 and a second docking site 105 are at each docking system 115, 117, respectively. Although the docking sites are shown as dotted lines in FIG. 1, these lines need not represent actual marks on the ground, but are merely an aid in reading this description.

  Also, although FIG. 1 shows both docking systems 115, 117 as being connected to terminal 101, in other configurations, the docking system is not directly connected to the terminal, but instead of another at the docking site. It may be connected to suitable means. In fact, the docking site may not be directly associated with a particular terminal, but may be associated with any designated site at the airport that can be docked for airport operation.

The state shown in FIG. 1 is a state in which the first aircraft 111 is entering the first docking site 103 along the ground guide line 107. The second aircraft 113 is located at the second docking site 105 and is connected to the terminal 101 via the passenger bridge 109 after the docking operation is normally performed.
Most of the first docking site 103 is covered with fog 119. It is believed that the fog 119 can spread into three-dimensional space in the docking site's atmosphere and hinder safe docking when the first aircraft 111 approaches the first docking system 115.

  As is well known, fog or rain affects the field of view mainly because incident electromagnetic radiation is scattered by water droplets in the atmosphere. During scattering, the irradiated water droplets re-radiate some of the incident electromagnetic radiation in all directions. In this case, the water droplet acts as a point source of re-radiant energy. According to the relationship between the size of the water droplet and the radiation wavelength, a part of the incident electromagnetic radiation is scattered in the opposite direction toward the radiation source. The relationship between the field of view and scattered electromagnetic radiation is extensively described in the literature. For example, “Ground-based remote sensing of visual range / Visual-range lidar”, German Engineers Association VDI 3786, or “Elastic Rider Theory, Practice, and Analysis” Method (Elastic Lidar: Theory, Practice and analysis methods) ”, V. A. Kovalev, W.M. E. Eichinger, Hoboken, N .; J. et al. , Wiley, 2004.

  In a docking system using electromagnetic radiation means (eg for pulse radiation), the amount of received energy reflected from the object to be detected is reduced when there is scattering. In a docking system using image means, the contrast of the image used decreases if there is scattering.

  The docking system 215 will now be described with reference to FIGS. 2a and 2b. This uses electromagnetic radiation in the form of radiation of pulses and reception of backscattered radiation of these pulses. The docking system 215 is configured to determine the distance to the approaching aircraft 240 in real time, and the view of the docking site between the docking system 215 and the approaching aircraft 240 is such that the aircraft 240 can be safely docked. Configured to show whether it is good enough.

  The docking system 215 of FIG. 2 a may represent any of the docking systems 115, 117 described above with respect to FIG. 1 and includes a control unit 221, a transmitter 223, and a receiver 225. The transmitter 223 is configured to emit electromagnetic radiation pulses in the form of laser radiation under the control of the control unit 221 (although other embodiments are transmissions configured to operate with radar pulses). Machine / receiver pair). As schematically shown in FIG. 2 a, radiation is emitted from the transmitter in a transmit beam 229 in the transmit beam direction 230. Correspondingly, the receiver receives the backscattered radiation with the receive beam 231 in the receive beam direction 232, also under the control of the control unit 221, and controls the signal representing the backscattered radiation. The unit 221 is configured to be fed.

Transmitter 223 and receiver 225 are configured to be able to be directed in any desired spatial direction via beam direction device 226 controlled by control unit 221. As those skilled in the art will appreciate, the beam directing device 226 may be implemented in the form of a mirror, stepper motor, or the like.
As shown in FIG. 1, the docking system 215 may form part of a larger system located at the airport terminal and may also be connected to an external control system 227 operated by airport staff.

Next, an operation in which the docking system 215 of FIG. 2 gives an instruction as to whether safe docking is possible will be described. Here, in determining the distance of the docking system 215 , the transmitter 223 and the receiver 225 are used to emit and receive electromagnetic pulses in the form of laser pulses or radar pulses. Please also refer to the flowchart of FIG.

The graph of FIG. 2b shows the distance-correction of the system when a pulse is emitted towards the homogeneous fog at radiation step 401 and the receiver 225 receives the backscattered radiation at reception step 403. A representative power distribution Z (r) of the corrected receiver signal is shown in the form of a receiver signal having a power distribution P (r). Next, in the calculation step 405, the value of the field of view V is calculated.
In calculation step 405, the distance corrected power distribution Z (r) is first calculated as Z (r) = r ² * P (r) to compensate that the received signal decreases by 1 / r ² over a long distance. . r is the distance between the transmitter / receiver and the reflecting / scattering object.

で計算することができる。ただし、
ｃ＝光速、

ｒ₀は送信機と受信機の視野が完全に重なり始める距離、
ｒ₁は信号が距離ｒ₀での最大値の１０％まで落ちた距離、
ｒ₂＝ｒ₁−ｒ₀
である。
Ｉ_r1の積分時間はｔ₀からｔ₁＝ｔ₀＋Δｔまで、またＩ_r2の積分時間はｔ₁からｔ₂＝ｔ₁＋Δｔまでであり、ｔ₀、ｔ₁、ｔ₂およびΔｔは図２ｂに定義するようにｒ₀、ｒ₁、ｒ₂およびΔｒに関係する。 Next, the field of view V is calculated from the received signal Z (r) corrected for distance using, for example, an algorithm disclosed in DE196642967 or using a so-called asymptotic approximation method. In this method, the field of view V is

Can be calculated with However,
c = speed of light,

r ₀ is the distance at which the fields of view of the transmitter and receiver begin to overlap completely,
r ₁ is the distance that the signal falls to 10% of the maximum value at distance r ₀ ,
r ₂ = r ₁ −r ₀
It is.
The integration time of I _r1 is from t ₀ to t ₁ = t ₀ + Δt, and the integration time of I _r2 is from t ₁ to t ₂ = t ₁ + Δt, where t ₀ , t ₁ , t ₂ and Δt are shown in FIG. Is related to r ₀ , r ₁ , r ₂ and Δr.

  Next, in a comparison step 407, the calculated field of view V is compared with a predetermined threshold value to provide an indication (ie, a signal) whether docking is possible. The specific value of the threshold value is determined empirically, for example. If the field of view V is larger than this threshold value, an instruction is given in the instruction step 409 that safe docking is possible because the field of view is good. However, if the field of view V is smaller than this threshold value, an instruction is given at step 411 that safe docking is not possible because the field of view is poor.

Referring now to FIG. 3, a docking system 315 using image means in the form of a camera 324 will be described. Similar to the previous embodiment, the docking system 315 is configured to determine in real time the distance to the approaching aircraft and whether the docking site visibility is good enough to allow the aircraft 340 to be safely docked. Configured as shown.
The docking system 315 of FIG. 3 may represent either of the docking systems 115, 117 described above with respect to FIG. 1, and is connected to the camera 324 and externally similar to the situation described above with respect to the embodiment of FIG. 2a. A control unit 321 connected to the control system 327 is provided.

The camera 324 is controlled to record an image of the contrast test object indicated by a dark spot 303 and a bright spot 304 at a distance d from the docking system 315. As those skilled in the art will appreciate, the test objects 303, 304 are any predetermined object or sign that is at a docking site within the field of view of the docking system (eg, part of the drawn guide line 107). Good. The mist 305 shown in FIG. 3 extends into the atmosphere between the docking system 315 and the approaching aircraft 340.

Next, the operation of the docking system 315 of FIG. 3 for giving an instruction as to whether safe docking is possible will be described. Here, in order to determine the distance, the control unit 321 records an image using the camera 324. In the recorded image, the first pixel represented by i and the second pixel represented by _j include image data of each site point P _i and P _j corresponding to each point 303, 304 of the measurement object. Please also refer to the flowchart of FIG.

After recording the image at the recording step 501, the calculation step 503 calculates the contrast between the two pixels i and j in the camera image corresponding to the two field points P _i and P _j at the same distance from the camera. . This contrast is then used as a measure of performance degradation due to reduced visibility, as will be explained later.

  As shown in FIG. 3, the contrast in the camera image has two effects due to light scattering by atmospheric particles. Direct transmission 307 is the attenuated irradiance received by the camera sensor along the line of sight from the site points 303, 304. The air scattered light (air light) 309 is the total amount of the environment irradiation 311 (sunlight, skylight, ground light) reflected in the line of sight by atmospheric particles.

ただし、
Ｅ⁽ⁱ⁾およびＥ^(j)は２つの画素ｉおよびｊでのそれぞれの輝度、
I_∞は環境照射の強さ、
ρは現場点３０３，３０４の正規化された放射輝度であって、現場点の反射率、正規化された環境照射スペクトル、およびカメラ３２４のスペクトル応答の関数、
βはカメラ３２４の前の大気の後方散乱係数、
ｄはシステム３１５と現場点３０３，３０４との間の距離、
である。 It is known that there is the following relationship. That is,

However,
E ⁽ⁱ⁾ and E ^(j) are the respective luminances at the two pixels i and j,
I _∞ is the intensity of environmental illumination,
ρ is the normalized radiance of the field points 303, 304 and is a function of the field point reflectivity, the normalized ambient illumination spectrum, and the spectral response of the camera 324;
β is the backscatter coefficient of the atmosphere in front of the camera 324,
d is the distance between the system 315 and the site points 303, 304;
It is.

これは、散乱係数βおよび霧３０５が存在する状態での現場点の深さと共にコントラストが指数関数的に劣化することを示す。
２つの画素の輝度Ｅは測定により得られ、２つの点の間のコントラストＣ（ｉ，ｊ）は

として計算される。 The observed contrast between P _i and P _j may be defined as:

This indicates that the contrast degrades exponentially with the scattering coefficient β and the depth of the field point in the presence of fog 305.
The luminance E of the two pixels is obtained by measurement, and the contrast C (i, j) between the two points is

Is calculated as

  Next, in a comparison step 505, the calculated contrast C is compared with a predetermined threshold to provide an indication (ie, a signal) whether docking is possible. The specific value of the threshold value is determined empirically, for example. If the contrast C is greater than this threshold, an indication step 507 gives an indication that safe docking is possible due to good visibility. However, if the contrast C is smaller than this threshold value, an instruction is given in the instruction step 509 that safe docking is not possible because the field of view is poor.

The present invention will be described in detail with reference to the accompanying drawings.
1 shows a schematic diagram of a docking site in which a docking system according to the present invention is arranged. FIG. 2a shows a schematic diagram of a docking system according to a first embodiment of the present invention. FIG. 2b is a graph of the response curve related to electromagnetic pulses reflected in the fog. 2 shows a schematic diagram of a docking system according to a second embodiment of the present invention. 3 is a flowchart of a method according to the present invention. 3 is a flowchart of a method according to the present invention.

Claims (19)

An aircraft docking system configured to be installed at a docking site, the system comprising distance determining means configured to determine at least a distance between the system and the aircraft using electromagnetic radiation signal receiving means. The distance determining means further includes
Measuring at least one characteristic of the receiver signal received by the signal receiving means relating to the field of view at the docking site;
Comparing the measured value of the at least one receiver signal characteristic with a threshold value;
Based on the comparison, a signal indicating whether the field of view at the docking site is sufficiently good to allow safe docking using the system;
An aircraft docking system configured as follows.   The aircraft docking system of claim 1, wherein the distance determining means is configured to measure the at least one receiver signal characteristic that is at least related to scattering of the electromagnetic radiation.   The aircraft docking system of claim 2, wherein the distance determining means comprises laser distance measuring means, and wherein the distance determining means is configured to measure the scattering of laser radiation.   The aircraft docking system of claim 2, wherein the distance determining means comprises radar distance measuring means, and wherein the distance determining means is configured to measure radar radiation scatter.   The aircraft docking system according to any of claims 2-4, wherein the distance determining means is configured to measure backscattered electromagnetic radiation.   6. The aircraft docking system of claim 5, wherein the distance determining means is configured to determine a power distribution of a received signal of backscattered electromagnetic radiation.   The distance determining means comprises signal receiving means having image means configured to provide a two-dimensional image at the docking site, and the distance determining means at least in contrast difference between at least two regions in the image. The aircraft docking system of claim 1, wherein the aircraft docking system is configured to measure at least one characteristic of an associated receiver signal.   The aircraft docking system of claim 7, wherein the image means is configured to determine the contrast difference between predetermined positions corresponding to at least two regions in the image at the docking site.   The aircraft docking system of claim 8, wherein the predetermined location is at substantially the same distance from the device.   10. An aircraft docking system according to any one of claims 7-9, wherein the imaging means is configured to detect electromagnetic radiation within at least a visible wavelength interval.   11. An aircraft docking system according to any one of claims 7-10, wherein the imaging means is configured to detect electromagnetic radiation at least within an infrared wavelength interval. A method of controlling aircraft docking using an aircraft docking system installed at a docking site, wherein the system uses electromagnetic radiation signal receiving means to determine at least the distance between the system and the aircraft A distance determining means configured, the distance determining means comprising:
Measuring at least one characteristic of the receiver signal received by the signal receiving means related to the field of view at the docking site;
Comparing the measured value of the at least one receiver signal characteristic with a threshold value;
Based on the comparison, providing a signal indicating whether the view at the docking site is sufficiently good to allow safe docking with the system;
How to control the docking of the aircraft.   The method of controlling aircraft docking according to claim 12, wherein measuring at least one receiver signal characteristic comprises measuring at least a scatter of the electromagnetic radiation.   The method of controlling aircraft docking according to claim 13, wherein the measuring includes measuring backscattered electromagnetic radiation.   The method of controlling aircraft docking according to claim 14, comprising determining a power distribution of the backscattered electromagnetic radiation.   The distance determining means comprises signal receiving means comprising image means configured to provide a two-dimensional image at the docking site, and measuring at least one characteristic of the receiver signal comprises at least 2 in the image The method of controlling aircraft docking according to claim 12, comprising measuring at least a contrast difference between two regions.   The determination of the contrast difference between the predetermined positions at the docking site includes determining a contrast difference between predetermined positions corresponding to the at least two regions in the image. Item 17. A method for controlling aircraft docking according to Item 16.   The method of controlling aircraft docking according to claim 17, wherein the predetermined position is at substantially the same distance from the system.   Computer program comprising software instructions for executing the method of any one of claims 12 to 18 when executed in a computer.

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