Device and method for measuring offset of ground running track of aircraft

Abstract

The invention relates to the technical field of aircraft ground transfer test equipment, in particular to an aircraft ground transfer track offset measuring device and method. The device is wide in application range, is suitable for various types of aircrafts and runway sites, and can be suitable for different types of aircrafts and runways only by properly adjusting the mounting positions of the high-precision laser transmitter, the front camera and the datum line laser transmitter and related parameters of the analysis computer in advance. The method is high in precision, and when the method for calculating the pixels on the shot image is adopted, the measurement precision of the method can be improved to the millimeter level. The method is low in cost, and compared with a GPS + satellite communication navigation method, the test cost of the method is reduced by more than 70%.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft geostrophic testing equipment, and in particular to a device and method for measuring the deviation of an aircraft ground operation trajectory. Background Art

[0002] The ground operation of the aircraft requires the pilot to control it through a dedicated aircraft controller at the ground control station. The direction of the aircraft's movement is controlled by inputting the front wheel turning angle command. In theory, when a 0° command is input, the front wheel angle of the aircraft is 0°, and the aircraft will move forward in a straight line. However, in reality, due to defects in the ground runway or extreme conditions such as ice and snow, the front wheels cannot be guaranteed to operate at the theoretical 0°. If the aircraft deviates at any angle during the transfer process, the aircraft will deviate from the set route and is likely to collide with surrounding aircraft, personnel and other objects, causing personal safety and economic losses.

[0003] At present, it is impossible to achieve high-precision self-operation trajectory correction by the aircraft itself. Based on this, a device and method for measuring the deviation of the ground operation trajectory of the aircraft are proposed. At present, the movement mode of aircraft in my country adopts the use of its own wheel-shaped structure to drive the ground after receiving the signal input remotely by the aircraft controller. When the pilot controls outside the runway, the angle of the front wheel is changed by inputting the signal to control the movement direction of the aircraft. However, when the aircraft cannot move according to the theoretical trajectory due to objective factors such as the site, the pilot cannot timely feedback and correct the aircraft's movement trajectory due to factors such as limited viewing angle, and the deviation is large. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a device and method for measuring the ground operation trajectory deviation of an aircraft, which adopts digital control and automated analysis and processing to solve the problem in the prior art that the aircraft itself cannot achieve high-precision self-operation trajectory correction.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] The device for measuring the deviation of the ground operation trajectory of an aircraft comprises:

[0007] A high-precision laser transmitter is used to be installed at the center axis of the lower surface of the front fuselage of the aircraft under test, located at the front end of the front landing gear compartment, irradiating vertically downward and irradiating on the runway to form a runway laser spot;

[0008] A forward-looking camera, which is used to be installed on the aircraft under test and capture images of the runway laser point and the runway reference line when the aircraft under test is in operation;

[0009] The baseline laser transmitter is placed on the ground or other stationary facilities and is used to illuminate the runway to form the runway baseline.

[0010] An analysis computer, which is connected to the forward-looking camera by wireless signal, and is used to obtain the image captured by the forward-looking camera, and determine the running track offset of the measured aircraft according to the images of the runway laser point and the runway reference line;

[0011] A data processing module, which is used to determine the motion trajectory offset of the measured aircraft based on the images of the runway laser point and the runway reference line;

[0012] The display module is used to be arranged in the ground control station of the aircraft under test to display the data of the running deviation of the aircraft under test.

[0013] The measurement method of the trajectory deviation measurement device for the ground operation of an aircraft is implemented by using the above-mentioned trajectory deviation measurement device, and comprises the following steps:

[0014] A baseline laser transmitter is used to illuminate a straight beam of light along the center line of the test runway, which falls on the ground to form the runway baseline.

[0015] Make the aircraft under test operate according to the taxiing speed and front wheel turning angle control requirements specified in the standard, and take images of the runway laser points and runway reference lines when the aircraft under test is operating.

[0016] The running track deviation of the measured aircraft is determined according to the images of the runway laser point and the runway reference line when the measured aircraft is running.

[0017] Before the aircraft under test is operated according to the taxiing speed and front wheel turning angle control requirements specified in the standard, the method also includes a step of obtaining a reference size, wherein the reference size is used to determine the motion offset of the aircraft under test.

[0018] The specific method flow is as follows:

[0019] First, we need to determine the ratio coefficient between the distance between the runway laser point on the captured image and the runway baseline and the actual measured distance. There are two calculation methods available. Regardless of which calculation method is used, we need to park the measured aircraft parallel to the ground baseline in advance, that is, the center axis of the aircraft is parallel to the ground baseline. The distance between the aircraft and the ground baseline should be as large as possible under the premise that the camera can shoot clearly, generally 20-30m.

[0020] Method 1: Park the aircraft under test parallel to the runway baseline, so that the runway laser point is separated from the runway baseline by a set distance S1.

[0021] Acquire a photographic image of the runway laser point and the runway baseline, measure a distance S2 between the runway laser point and the runway baseline on the image, and record a value of S2;

[0022] Calculate the proportionality coefficient between the actual distance between the runway laser point and the runway baseline and the distance between the runway laser point and the runway baseline on the image: proportionality coefficient A = S1 / S2.

[0023] Method 2: Park the aircraft under test parallel to the runway baseline, so that the runway laser point is separated from the runway baseline by a set distance S1.

[0024] The captured image of the runway laser point and the runway baseline is obtained, and the number of pixels N between the center points of the pixels corresponding to the ground laser point and the ground baseline in the image is obtained by using a computer and a camera program.

[0025] Calculate the ratio coefficient B = S1 / N between the distance between the runway laser point and the runway baseline and the number of pixels between the corresponding pixel center points of the ground laser point and the ground baseline in the image.

[0026] According to the images of the runway laser point and the runway reference line when the aircraft under test is in operation, the operation offset of the aircraft under test and the offset angle of the aircraft under test are determined, and the process is as follows:

[0027] First, we need to use the images captured by the analysis computer and the forward-looking camera to calculate the relative distance between the aircraft and the runway baseline in real time, and collect data at fixed time intervals of △t. The value of △t should be as small as possible within the range allowed by the equipment performance, such as 0.01s, 0.02s.

[0028] Therefore, when using the calculation method of method 1, we can calculate the lateral displacement of the aircraft at any time in a time interval during its movement.

[0029] △x=x2-x1

[0030] Where x2 is the relative distance between the runway laser point and the runway baseline at that moment, and x1 is the relative distance between the runway laser point and the runway baseline in the previous time interval. We stipulate that when the runway laser point is on the right side of the runway baseline, x is a positive number; when the runway laser point is on the left side of the runway baseline, x is a negative number. From this, we can further calculate that the lateral deviation speed of the aircraft at that moment is

[0031] v1=A·△x / △t

[0032] Further combined with the aircraft's own speed v at that moment, we can calculate the angle between the aircraft's instantaneous direction of motion and the runway baseline at that moment:

[0033] Ф=arcsin(v1 / v)

[0034] After calculating the angle, we give the following feedback instructions to the aircraft controller and analysis computer: every time interval △t2, a signal is applied to the aircraft to set the current front wheel turning angle to -2Ф. △t2 should be a positive integer multiple of △t1, and is generally equal to △t1 if performance permits, thereby achieving the effect of negative feedback to adjust the aircraft's motion trajectory.

[0035] When the calculation method of method 2 is used to obtain the value of v1, the method is as follows:

[0036] During the movement of the aircraft, we can calculate the difference in the number of pixels of the lateral offset at any time interval.

[0037] △N=N2-N1

[0038] Where N2 is the number of pixels of the runway laser point and the runway baseline on the image at that moment, and N1 is the number of pixels of the runway laser point and the runway baseline on the image of the previous time interval. When the runway laser point is on the right side of the runway baseline, N is a positive number; when the runway laser point is on the left side of the runway baseline, N is a negative number. From this, we can further calculate that the lateral deviation speed of the aircraft at that moment is

[0039] v1=B·△N / △t.

[0040] Beneficial effects of the present invention:

[0041] 1. Wide range of applications. The system is applicable to various types of aircraft and runway sites. As long as the installation positions of the high-precision laser transmitter 1, the front camera 5, the baseline laser transmitter 7 and the relevant parameters of the analysis computer are properly adjusted in advance, it can be applied to different types of aircraft and runways.

[0042] 2. High accuracy: When the method of calculating the pixels on the captured image (i.e., method 2) is adopted, the measurement accuracy of this scheme can be improved to the millimeter level.

[0043] 3. Low cost. Compared with the GPS+satellite navigation method, the experimental cost of this solution is reduced by more than 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Aircraft ground operation trajectory deviation measuring device.

[0045] In the figure: 1. High-precision laser transmitter; 2. Aircraft under test; 3. Ground laser point; 4. Ground reference line; 5. Forward-looking camera; 6. Analysis computer; 7. Reference line laser transmitter; 8. Aircraft controller. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application.

[0047] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0048] Embodiment 1:

[0049] Figure 1 FIG. 1 is a schematic diagram of a track deviation measurement device according to an embodiment of the present invention. Figure 1 As shown, the present invention provides a track deviation measuring device, including: a high-precision laser transmitter 1, a forward-looking camera 5 and an analysis computer 6.

[0050] The reference line laser transmitter 7 is installed at a corresponding position on the runway, and is used to emit laser to the runway to form a ground reference line 4. The high-precision laser transmitter 1 is used to be installed on the aircraft under test 2, and should be installed near the front landing gear, irradiating vertically downward, and irradiating on the ground to form a ground laser point 3; the forward-looking camera 5 is used to be installed on the aircraft under test 2, and capture images of the ground laser point 3 and the ground reference line 4 when the aircraft under test 2 is traveling; the analysis computer 6 is connected to the signal of the forward-looking camera 5, and is used to obtain the image captured by the forward-looking camera 5, and determine the motion offset of the aircraft under test 2 according to the images of the ground laser point 3 and the ground reference line 4.

[0051] When the trajectory deviation measuring device is used, a high-precision laser transmitter 1 is installed at the front midpoint of the measured aircraft 2, the high-precision laser transmitter 1 is vertically downward and irradiates the ground to form a ground laser point 3, and a forward-looking camera 5 is installed near the high-precision laser transmitter 1, and the adjustment of its height and focal length ensures that its viewing angle range can cover the extreme position of the deviation of the ground reference line 4 and the ground laser point 3 on the ground; the measured aircraft 2 is driven in the direction of the ground reference line 4, and the image of the ground laser point 3 relative to the ground reference line 4 obtained by the forward-looking camera 5 during the driving of the measured aircraft 2 is transmitted to the analysis computer 6 in real time, and the analysis computer 6 automatically captures the ground laser point 3 and the ground reference line 4 in the image, calculates according to the relative position parameters of the ground laser point 3 and the ground reference line 4, determines the movement deviation of the measured aircraft 2, and then performs negative feedback adjustment on the actual movement direction of the aircraft through the aircraft controller 7 to correct the movement trajectory.

[0052] Embodiment 2:

[0053] Now we want to use this system to perform negative feedback regulation of the motion trajectory of a certain aircraft.

[0054] Firstly, we place the reference line laser transmitter 7 at the corresponding position on the runway, and transmit laser to the runway to form a ground reference line 4. The direction of the ground reference line 4 is the theoretical movement direction of the aircraft 2 under test.

[0055] We install the high-precision laser transmitter 1 on the front landing gear of the aircraft, and install the front camera 5 near the high-precision laser transmitter 1, so that it can clearly capture the ground laser point 3 and the ground reference line 4 formed on the ground when the high-precision laser transmitter 1 is irradiated vertically downward.

[0056] We park the aircraft under test parallel to the ground reference line, that is, the central axis of the aircraft is parallel to the ground reference line, the distance between the aircraft and the ground reference line is set to 20m, and ensure that the front camera 5 can clearly capture the ground reference line 4 and the ground laser point 3.

[0057] First, we use method 1 to calculate:

[0058] By taking an image of the runway laser point 3 and the runway reference line 4, and measuring the distance between the runway laser point and the runway reference line on the image as 160 mm, the proportional coefficient between the actual distance between the runway laser point and the runway reference line and the distance between the runway laser point and the runway reference line on the image can be calculated: proportional coefficient A=125.

[0059] We set the data collection interval △t of the images taken by the analysis computer 6 and the forward-looking camera 5, and we set △t1=0.1s; the time interval △t2 of the analysis computer 6 sending the current front wheel turning angle negative feedback control signal to the tested aircraft 2 through the flight controller 8 is set to be equal to △t1, that is, 0.1s.

[0060] After the above work is completed, we place the aircraft under test 2 at the starting position, and send a command to the aircraft under test 2 through the aircraft controller 8 to make it start moving along the direction of the ground reference line 4.

[0061] At a certain moment, the trajectory of the aircraft is deviated due to factors such as the venue. At this time, the distance x2 between the runway laser point 3 and the runway baseline 4 in the last image taken by the front camera is analyzed and measured by the computer 6 to be 25.6 mm. The distance x1 between the runway laser point 3 and the runway baseline 4 in the image of the previous time interval is measured to be 25.2 mm. It can be obtained that the value of the lateral offset in this time interval is △x=x2-x1=0.4mm, and then the lateral speed at this moment is calculated to be v1=A·△x / △t=0.5m / s. At this time, the total velocity of the aircraft is If the speed is v=8m / s, it can be calculated that the angle between the instantaneous movement direction of the aircraft and the runway baseline at this moment is Ф=arcsin(v1 / v)=3.5°, that is, the aircraft is deviating from the theoretical direction to the right at an angle of 3.5°. At this time, the analysis computer 6 automatically sends a signal to the aircraft through the aircraft controller 8 by a pre-set program, sets the current front wheel turning angle to -2Ф=-7°, and turns the front wheel to the left 7° to correct the motion trajectory, and adjusts this angle in real time every 0.1s.

[0062] We then use method 2 to get the value of v1:

[0063] The image of the runway laser point 3 and the runway reference line 4 is taken, and the number of pixel points between the runway laser point and the runway reference line on the image is measured by the analysis calculator 6 as 100,000. Then, the proportional coefficient B=S1 / N=0.2 (in mm / pixel) between the distance between the runway laser point and the runway reference line and the number of pixels between the corresponding pixel center points of the ground laser point and the ground reference line in the image can be calculated.

[0064] We set the data collection interval △t of the images taken by the analysis computer 6 and the forward-looking camera 5, and we set △t1=0.1s; the time interval △t2 of the analysis computer 6 sending the current front wheel turning angle negative feedback control signal to the tested aircraft 2 through the flight controller 8 is set to be equal to △t1, that is, 0.1s.

[0065] After the above work is completed, we place the aircraft under test 2 at the starting position, and send a command to the aircraft under test 2 through the aircraft controller 8 to make it start moving along the direction of the ground reference line 4.

[0066] At a certain moment, the trajectory of the aircraft deviates due to factors such as the venue. At this time, the number of pixels between the runway laser point 3 and the runway baseline 4 in the last image taken by the front camera is measured by the analysis computer 6 to be 16,000, and the number of pixels between the runway laser point 3 and the runway baseline 4 in the image of the previous time interval is measured to be 15,750. The difference in the number of pixels in this time interval can be calculated to be △N = N2-N1 = 250, and then the lateral speed at this moment is calculated as v1 = B·△N / △

[0067] t=0.5m / s.

Claims

1. An aircraft ground operation trajectory deviation measuring device, characterized in that: include: A high-precision laser transmitter (1), a forward-looking camera (5), an analysis computer (6), and a reference line laser transmitter (7); The high-precision laser transmitter (1) is installed at the central axis of the lower surface of the front fuselage of the aircraft (2) under test, located at the front end of the front landing gear compartment, irradiates vertically downward, and irradiates on the runway to form a runway laser point; The forward-looking camera (5) is used to be installed on the aircraft under test (2) to capture images of the runway laser point and the runway reference line when the aircraft under test (2) is in operation; The reference line laser transmitter (7) is placed on the ground or other stationary facilities and is used to illuminate the runway to form a runway reference line; The analysis computer (6) is connected to the forward-looking camera (5) by wireless signals, and is used to obtain the image captured by the forward-looking camera (5), and determine the running track deviation of the measured aircraft (2) based on the images of the runway laser point and the runway reference line; The data processing module is used to determine the movement track offset of the measured aircraft (2) based on the images of the runway laser point and the runway reference line; A display module is used to be arranged in a ground control station of the aircraft under test (2) to display data on the running deviation of the aircraft under test (2).

2. A measuring method of an aircraft ground operation trajectory deviation measuring device, characterized in that: Here are the steps: The first step is to use a reference line laser transmitter (7) to emit a straight line of light along the center line of the test runway and onto the ground to form a runway reference line; Step 2: operate the aircraft under test (2) according to the taxiing speed and front wheel turning angle control requirements specified in the standard, and take images of the runway laser point and the runway reference line when the aircraft under test (2) is operating; Step 3: determining the running track deviation of the aircraft under test (2) based on the images of the runway laser point and the runway reference line when the aircraft under test (2) is running; Step 4: Before the aircraft under test (2) is operated according to the taxiing speed and front wheel turning angle control requirements specified in the standard, the step of obtaining reference dimensions is also included, and the reference dimensions are used to determine the movement offset of the aircraft under test (2).

3. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 2, characterized in that: In the third step, the proportionality coefficient between the distance between the runway laser point and the runway reference line and the actually measured distance requires that the measured aircraft (2) be parked parallel to the ground reference line (4) in advance, that is, the central axis of the aircraft is parallel to the ground reference line (4).

4. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 3, characterized in that: In the third step, the proportionality coefficient between the distance between the runway laser point and the runway baseline and the actually measured distance adopts method 1: Parking the aircraft (2) under test parallel to the runway baseline so that the runway laser point is spaced a set distance S1 from the runway baseline; Acquire a photographic image of the runway laser point and the runway baseline, measure a distance S2 between the runway laser point and the runway baseline on the image, and record a value of S2; The proportionality coefficient between the actual distance between the runway laser point and the runway baseline and the distance between the runway laser point and the runway baseline on the image is calculated: proportionality coefficient A = S1 / S2.

5. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 3, characterized in that: In the third step, the proportionality coefficient between the distance between the runway laser point and the runway baseline and the actually measured distance adopts method 2: The aircraft (2) to be tested is parked parallel to the runway baseline, so that the runway laser point is separated from the runway baseline by a set distance S1; Obtaining a photographic image of the runway laser point and the runway reference line, and using a computer and a camera program to obtain the number of pixels N between the positions of the corresponding pixel centers of the ground laser point (3) and the ground reference line (4) in the image; The proportionality coefficient B=S1 / N between the distance between the runway laser point and the runway reference line and the number of pixels between the corresponding pixel center positions of the ground laser point (3) and the ground reference line (4) in the image is calculated.

6. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 4, characterized in that: In the third step, the running offset of the aircraft (2) under test and the offset angle of the aircraft are determined based on the images of the runway laser point and the runway reference line when the aircraft (2) under test is running. The process is as follows: Using the images captured by the analysis computer (6) and the forward-looking camera (5), the relative distance between the aircraft and the runway baseline is calculated in real time, and data is collected at fixed time intervals of △t, wherein the value of △t is not greater than 0.02s; When the calculation method of method 1 is used, the lateral displacement of the aircraft at any time in a time interval during the movement is calculated as △x=x2-x1 Where x2 is the relative distance between the runway laser point and the runway baseline at that moment, and x1 is the relative distance between the runway laser point and the runway baseline in the previous time interval. It is stipulated that when the runway laser point is on the right side of the runway baseline, x is a positive number; when the runway laser point is on the left side of the runway baseline, x is a negative number. It is further calculated that the lateral deviation speed of the aircraft at that moment is v1=A·△x / △t Further combined with the aircraft's own speed v at that moment, the angle between the aircraft's instantaneous direction of motion and the runway baseline is calculated to be Φ = arcsin (v1 / v) After calculating the angle, the following feedback instructions are given to the aircraft controller (8) and the analysis computer (6): every time interval △t2, a signal is applied to the aircraft to set the current front wheel turning angle to -2Ф. △t2 should be a positive integer multiple of △t1, and is generally equal to △t1 if performance permits, so as to achieve the effect of negative feedback to adjust the aircraft's motion trajectory.

7. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 4, characterized in that: When the value of v1 is obtained by using the calculation method of method 2, the method is as follows: The difference in the number of pixels of the lateral offset of the aircraft at any time in a time interval during its motion is calculated. △N=N2-N1 Where N2 is the number of pixels of the runway laser point and the runway baseline on the image at that moment, and N1 is the number of pixels of the runway laser point and the runway baseline on the image of the previous time interval at that moment; when the runway laser point is on the right side of the runway baseline, N is a positive number; when the runway laser point is on the left side of the runway baseline, N is a negative number, and thus the lateral deviation speed of the aircraft at that moment is further calculated to be v1=B·△N / △t.

8. The measuring method of the aircraft ground operation trajectory deviation measuring device as claimed in claim 3, characterized in that: In the third step, the distance between the measured aircraft (2) and the ground reference line (4) is 20m-30m.

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