Aircraft terminal area navigation parameter calculation method based on multi-view camera

Abstract

According to the multi-camera-based aircraft terminal area navigation parameter calculation method, an aircraft is provided with a plurality of cameras and a controller, the cameras operate a binocular camera system, the controller comprises an image processing module, and the method comprises the following steps: acquiring a video image containing a target runway in a terminal area in real time through the cameras; the video image is identified and processed through an image processing module to identify parameters of the target runway, and the parameters comprise four end points of the target runway; the image processing module is used for calculating distances between the aircraft and four end points of the target runway through a binocular vision algorithm, and calculating visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm; the aircraft is guided to land or land on the target runway according to the distance and the visual navigation parameters, the dependence on airport facilities is reduced, and the application range of the automatic take-off and landing function of the aircraft is expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of airborne graphics and images, and in particular relates to a method for calculating navigation parameters of an aircraft terminal area based on a multi-camera. Background Art

[0002] The approach phase is a critical phase in an aircraft's flight. In order to reduce the pilot's operating load during the landing phase and implement automatic approach and landing, some airports are equipped with instrument landing equipment (ILS) and corresponding levels of lighting systems, runways, and airport operating procedures. When the aircraft approaches, these facilities can guide the aircraft not only in the lateral direction relative to the runway axis but also in the longitudinal direction relative to the glide path. The instrument landing equipment requires high-frequency maintenance and overhaul, which makes the equipment cost and maintenance and operation cost very expensive, thereby limiting the operating range of the automatic approach. Summary of the invention

[0003] In view of this, the present invention provides a method for calculating aircraft terminal area navigation parameters based on a multi-camera, which solves the technical problem that the methods of the prior art result in high costs for airport navigation facilities.

[0004] A method for calculating navigation parameters of an aircraft terminal area based on a multi-camera, wherein the aircraft is equipped with multiple cameras and a controller, wherein the cameras operate a binocular camera system, and the controller includes an image processing module, and the method includes:

[0005] A video image of a terminal area including a target runway is acquired in real time by a camera, and the video image is processed by an image processing module to identify parameters of the target runway, the parameters including four endpoints of the target runway;

[0006] The image processing module calculates the distance between the aircraft and the four endpoints of the target runway through a binocular vision algorithm, and calculates the visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm;

[0007] Guide the aircraft to land or land on the target runway based on distance and visual navigation parameters.

[0008] The technical beneficial effects of the present invention are:

[0009] The present invention focuses on the airborne equipment itself, captures the terminal area through onboard sensors, and calculates navigation information such as lateral deviation, longitudinal deviation and distance similar to the ILS system through visual methods, thereby improving the universality of automatic approach of aircraft and reducing airport operating costs. In addition, like traditional ILS navigation facilities and other similar airport sensor equipment, it can obtain navigation and position information such as aircraft during approach, reduce dependence on airport facilities, and expand the scope of application of automatic take-off and landing functions of aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0012] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0013] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0014] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0015] like Figure 1 The method for calculating the navigation parameters of the aircraft terminal area based on a multi-camera is shown, the aircraft is equipped with multiple cameras and a controller, the camera operates a binocular camera system, the controller includes an image processing module, and the method includes:

[0016] A video image of a terminal area (e.g., an airport) including a target runway is acquired in real time by a camera, and the video image is processed by an image processing module to identify parameters of the target runway, the parameters including four endpoints of the target runway;

[0017] The image processing module calculates the distance between the aircraft and the four endpoints of the target runway through a binocular vision algorithm, and calculates the visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm;

[0018] Guide the aircraft to land or land on the target runway based on distance and visual navigation parameters.

[0019] The method of the present invention detects the position of the airport runway and tracks it in real time, measures the distance information between the aircraft and the airport target runway through binocular or multi-camera and visual methods, and calculates the lateral deviation information and longitudinal deviation information of the aircraft relative to the target runway through multiple cameras and visual methods. The present invention can obtain navigation and position information during the approach of the aircraft, just like traditional ILS navigation facilities and other similar airport sensor equipment, reduce dependence on airport facilities, and expand the scope of application of the automatic take-off and landing function of the aircraft.

[0020] As a specific implementation method provided in this case, the visual navigation parameters include the distance D between the aircraft and the centerline of the runway entrance, the lateral deviation Loc and the longitudinal deviation Gs. The visual navigation parameters are calculated using the three-point positioning principle. There are more than one binocular camera system. When the aircraft is approaching from far away, more than two sets are more suitable. The four identified runway endpoints can be combined with any three runway endpoints to optimize the calculation results.

[0021] Furthermore, the image processing module calculates the distance between the four endpoints of the aircraft relative to the target runway through a binocular vision algorithm, and calculates the visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm, including the determination of the video image, specifically,

[0022] At least two or more cameras on the aircraft form a binocular vision system to acquire video images of the terminal area including the target runway in real time. Real-time identification of the four endpoints of the target runway in the physical environment, P1 (x1, y1, z1), P2 (x2, y2, z2), P3 (x3, y3, z3), P4 (x4, y4, z4), where P1 and P2 are the runway entrance endpoints, and P3 and P4 are the runway end endpoints. The binocular camera system collects two groups of runway images with four endpoints. The first group of runway images includes PL1 (xl1, yl1), PL2 (xl2, yl2), PL3 (xl3, yl3) and PL4 (xl4, yl4), and the second group of runway images includes PR1 (xr1, yr1), PR2 (xr2, yr2), PR3 (xr3, yr3) and PR4 (xr4, yr4);

[0023] Determine the pixel difference between each endpoint and the corresponding endpoint (e.g., the pixel difference between PL1 and PR1, the pixel difference between PL2 and PR2, etc.) and obtain the intrinsic parameter matrix of the camera;

[0024] All pixel differences and the intrinsic parameter matrix are used to determine the distances of the endpoints of the actual physical space of the target runway relative to the camera through the distance calculation software, where the distance parameter D = f*b / (xr'-xl'), where xr' is the horizontal coordinate of each point in the second group of runway images, xl' is the horizontal coordinate corresponding to each point in the first group of runway images and each point in the second group of runway images, and the vertical coordinates are generally equal, f is the focal length of the camera, and b is the distance between the optical axes of the cameras, which are all fixed parameters;

[0025] The coordinates P1, P2, P3 and P4 of the four endpoints in the physical environment of the target runway are obtained. All the distances are calculated by the positioning algorithm to obtain the relative position information P (x, y, z) of the aircraft relative to the target runway in the physical space, which is expressed as:

[0026] In the formula, the distances between the camera and each point P1, P2, P3, and P4 of the target runway are expressed as D1, D2, D3, and D4, respectively. Generally, the coordinates are established with the physical space target runway as a circle, and the distances D1, D2, D3, and D4 between the four endpoints of the aircraft relative to the target runway are calculated by the binocular vision algorithm, wherein D1, D2, D3, and D4 are the distances between the aircraft and the points P1, P2, P3, and P4, respectively. Preferably, the three-point positioning algorithm principle is used to calculate the optimal solution (x, y, z) of the relative coordinates of the aircraft relative to the target runway by combining any three points of D1, D2, D3, and D4 and applying the least squares method;

[0027] According to the relative position information P(x,y,z), the distance D, the lateral deviation Loc and the longitudinal deviation Gs are calculated.

[0028] The distance D between the aircraft and the centerline of the runway entrance is obtained through the distance relationship between two points in space:

[0029]

[0030] The lateral deviation parameter Loc satisfies:

[0031]

[0032] The longitudinal deviation parameter Gs satisfies:

[0033] Where, is the glide path angle θ of the target runway.

[0034] The two onboard cameras on the aircraft use visual algorithms to calculate the terminal area navigation parameters. The navigation parameters include the distance parameter D, the lateral deviation parameter Loc, and the longitudinal deviation parameter Gs. The purpose is to focus on the onboard equipment itself, capture the terminal area through the onboard sensor, and calculate the lateral deviation, longitudinal deviation and distance and other navigation information similar to the ILS system through visual methods, thereby improving the universality of the aircraft's automatic approach and reducing airport operating costs. In the approach phase, the aircraft relies on the distance parameter D, lateral deviation parameter Loc, and longitudinal deviation parameter Gs calculated above to achieve the purpose of automatic landing by relying only on the onboard equipment itself, replacing the existing ILS system.

[0035] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for calculating navigation parameters of an aircraft terminal area based on a multi-camera, wherein the aircraft is equipped with multiple cameras and a controller, characterized in that: The camera runs a binocular camera system, the controller includes an image processing module, and the method includes: A video image of a terminal area including a target runway is acquired in real time by a camera, and the video image is processed by an image processing module to identify parameters of the target runway, the parameters including four endpoints of the target runway; The image processing module calculates the distance between the aircraft and the four endpoints of the target runway through a binocular vision algorithm, and calculates the visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm; Guide the aircraft to land or land on the target runway based on distance and visual navigation parameters.

2. The method for calculating aircraft terminal area navigation parameters according to claim 1, characterized in that: The visual navigation parameters include the distance D between the aircraft and the centerline of the runway entrance, the lateral deviation Loc and the longitudinal deviation Gs.

3. The method for calculating aircraft terminal area navigation parameters according to claim 2, characterized in that: The visual navigation parameters are calculated using the three-point positioning principle.

4. According to the visual navigation calculation method of claim 2, any three of the four identified runway endpoints can be combined to optimize the calculation result.

5. The binocular camera system according to claim 2, characterized in that: The image processing module calculates the distance between the four endpoints of the aircraft relative to the target runway through a binocular vision algorithm, and calculates the visual navigation parameters of the aircraft relative to the target runway through a three-point positioning algorithm, including: The binocular camera system collects two groups of runway images with four endpoints, the first group of runway images includes PL1 (xl 1, yl 1), PL2 (xl 2, yl 2), PL3 (xl 3, yl 3) and PL4 (xl4, yl4), and the second group of runway images includes PR1 (xr1, yr1), PR2 (xr2, yr2), PR3 (xr3, yr3) and PR4 (xr4, yr4); Determine the pixel difference between each endpoint and the corresponding endpoint and obtain the camera's intrinsic parameter matrix; All the pixel differences and the intrinsic parameter matrix are used to determine the distances of the endpoints of the actual physical space of the target runway relative to the camera through the distance calculation software, wherein the distance parameter D=f*b / (xr'-xl'), where xr' is the horizontal coordinate of each point of the second group of runway images, xl' is the horizontal coordinate of each point of the first group of runway images and each point of the second group of runway images, f is the focal length of the camera, and b is the distance between the optical axes of the cameras; The coordinates P1, P2, P3 and P4 of the four endpoints in the physical environment of the target runway are obtained. All the distances are calculated by the positioning algorithm to obtain the relative position information P (x, y, z) of the aircraft relative to the target runway in the physical space, which is expressed as: In the formula, the distances between the camera and each point P1, P2, P3, and P4 on the target runway are expressed as D1, D2, D3, and D4, respectively; Calculate the least squares solution of x, y, and z; According to the relative position information P (x, y, z), the distance D, lateral deviation Loc and longitudinal deviation Gs are calculated. The distance D between the aircraft and the centerline of the runway entrance is obtained through the distance relationship between two points in space: The lateral deviation parameter Loc satisfies: The longitudinal deviation parameter Gs satisfies: Where θ is the glide path angle of the target runway.

Images