Railway inspection method based on unmanned aerial vehicle

Abstract

The invention relates to the technical field of railway inspection, in particular to a railway inspection method based on an unmanned aerial vehicle. The unmanned aerial vehicle performs railway inspection based on a railway inspection platform, and the railway inspection method comprises the following steps: establishing an unmanned aerial vehicle flight path model for planning the flight path of the unmanned aerial vehicle; the unmanned aerial vehicle flight path model comprises a flight path altitude Hi function and a flight path longitude Li and latitude Bi function; the flight path altitude function is determined by adopting the gradient of a railway line and the height of a field obstacle; and the longitude and latitude functions of the flight path are determined by adopting a cubic spline interpolation method, so that the unmanned aerial vehicle can be better guided to automatically cruise along the railway line, the requirements of railway inspection under special conditions can be met, the cruise safety is ensured, and the practical value is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of railway inspection, and particularly relates to a railway inspection method based on a UAV. BACKGROUND

[0002] Traditional railway inspection methods mainly include manual inspection and track inspection vehicle inspection. In the manual inspection, skilled inspectors detect disasters and hidden dangers in railway lines and auxiliary facilities by naked eyes or handheld devices. In the track inspection vehicle inspection, a special track inspection vehicle carries equipment to carry out inspection along the track. Both methods have problems such as low efficiency, poor night inspection conditions, low inspection frequency, narrow inspection area, low automation degree, and are constrained by the comprehensive maintenance window. The inspection during the operation time cannot be realized by the track inspection vehicle, so only manual inspection can be used, and the problems of low inspection efficiency and insufficient inspection coverage become more prominent.

[0003] Therefore, it is necessary to provide an improved technical solution for the above-mentioned problems of the prior art. SUMMARY

[0004] The present application aims to provide a railway inspection method based on a UAV to solve or alleviate the above-mentioned problems in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solution: The present application provides a railway inspection method based on a UAV, the UAV performs railway inspection based on a railway inspection platform, and the railway inspection method comprises the following steps: establishing a UAV flight path model for planning a UAV flight path; The UAV flight path model comprises a flight path altitude H i function, a flight path longitude L i and a flight path latitude B i function. The flight path altitude function is determined by the railway line slope and the height of the on-site obstacle. The flight path longitude and latitude functions are determined by the cubic spline interpolation method.

[0006] Preferably, the determination of the railway line slope and the height of the on-site obstacle comprises the following steps: Step S1: Pre-inspect the height of the on-site obstacle of the railway; Step S2: Measure the ground altitude information and the height information of the on-site obstacle according to the RTK; Step S3: Determine the altitude of the UAV flight path.

[0007] Preferably, the step S3 is specifically as follows: Let the ground elevation height be H0, and the height of the obstacle be ΔH, then the elevation of the flight path of the unmanned aerial vehicle is H i = H0+ΔH.

[0008] Preferably, the determination by using the cubic spline interpolation method comprises: Step S1: obtaining the coordinate values of the start point, end point and interval sampling points of the inspection section; Step S2: based on the above coordinate values, interpolation conditions, continuity conditions and boundary conditions, a cubic spline interpolation function S i (L).

[0009] Preferably, the railway inspection platform comprises a positioning module, a control module, a holder, and a camera. The positioning module is used to obtain the three-dimensional coordinates of the unmanned aerial vehicle. The control module is used to control the unmanned aerial vehicle to automatically cruise according to the flight path model of the unmanned aerial vehicle. The holder is used to connect the unmanned aerial vehicle and the camera. The camera is used to collect video data along the railway.

[0010] Preferably, the positioning module comprises a ground positioning module and a sky positioning module. The ground positioning module is fixedly arranged on the ground, and is used to continuously receive satellite signals to calculate the three-dimensional coordinates of the position thereof, and transmit the relevant position information to the sky positioning module. The sky positioning module is arranged on the unmanned aerial vehicle, and is used to calculate the three-dimensional coordinates of the unmanned aerial vehicle in combination with the GPS information and the position information provided by the ground positioning module.

[0011] Compared with the closest prior art, the technical scheme of the embodiments of the present application has the following beneficial effects: The technical scheme described in the present application can better guide the automatic cruising of the unmanned aerial vehicle along the railway line, can meet the needs of railway inspection under special conditions and ensure the cruising safety, and has high practical value. BRIEF DESCRIPTION OF DRAWINGS

[0012] The drawings accompanying the specification of the present application form a part of the present application, and are used to provide a further understanding of the present application, the illustrative embodiments of the present application and the description thereof serve to explain the present application, and do not constitute an improper limitation on the present application. Among them: Figure 1 The figure is a schematic diagram of the railway inspection platform architecture according to some embodiments of the present application. DETAILED DESCRIPTION

[0013] The application will be described in detail below with reference to the drawings and embodiments. Various examples are provided by way of explanation of the application but not to limit the application. It will be apparent to those skilled in the art that modifications and variations can be made in the application without departing from the scope or spirit of the application. For example, features shown or described as part of one embodiment can be used in another embodiment to yield still a further embodiment. It is therefore intended that the application encompass such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0014] In the following description, the terms "first / second / third" are merely to distinguish similar objects, and do not represent a specific order of the objects. Understandably, the "first / second / third" can be interchanged with a specific order or sequence as allowed, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification herein is for describing the embodiments of the application only and is not intended to be limiting of the application.

[0016] In the description of the application, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and do not require the application to be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the application. The terms "connected", "connected", "provided" used in the application should be understood broadly, for example, it can be fixedly connected or detachably connected; it can be directly connected or indirectly connected through intermediate components; it can be wired electrical connection, wireless electrical connection or wireless communication signal connection, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0017] The application will be described in detail below with reference to the drawings and embodiments. Various examples are provided by way of explanation of the application but not to limit the application. It will be apparent to those skilled in the art that modifications and variations can be made in the application without departing from the scope or spirit of the application. For example, features shown or described as part of one embodiment can be used in another embodiment to yield still a further embodiment. It is therefore intended that the application encompass such modifications and variations as fall within the scope of the appended claims and their equivalents. Figure 1 A railway inspection method based on a UAV will be further described in detail.

[0018] A railway inspection method based on a UAV, the UAV performs railway inspection based on a railway inspection platform, the railway inspection method comprising: establishing a UAV flight path model for planning a UAV flight path; The UAV flight path model comprises a flight path altitude H i a function of the latitude B i and the longitude L i and the latitude B The flight path altitude function is determined by the railway line slope and the height of the on-site obstacles; The flight path longitude and latitude function is determined by the cubic spline interpolation method.

[0019] The cubic spline interpolation method is a method for solving a smooth curve passing through a series of shape value points by solving a three-moment equation set. The cubic spline curve obtained by solving is smooth everywhere, and the degree is ≤ 3 in each small interval. Considering that the turning radius of the railway line is above 300 m, and the curvature changes gently at the turning, the smoothness is good, so the cubic spline curve can well represent the functional relationship between the longitude and latitude of the railway line. The RTK is used to obtain the coordinate points on the experimental railway line as the shape value points of the cubic spline curve, and the longitude and latitude cubic spline curve of the UAV flight path is solved based on this.

[0020] The determination of the railway line slope and the height of the on-site obstacles includes: Step S1: Pre-inspect the height of the on-site obstacles of the railway; Step S2: According to the RTK measured ground elevation information and the on-site obstacle height information; Step S3: Determine the altitude of the UAV flight path.

[0021] Step S3 is specifically: Let the ground elevation be H0, and the obstacle height be ΔH, then the altitude of the UAV flight path is H i = H0+ΔH.

[0022] The determination by the cubic spline interpolation method includes: Step S1: Obtain the coordinate values of the start point, end point and interval sampling points of the inspection section; Step S2: Based on the above coordinate values, interpolation conditions, continuity conditions and boundary conditions, a cubic spline interpolation function S i (L) is established.

[0023] The cubic spline function between the longitude and latitude of the UAV flight path is S(L). Then at the sampling point L i , the solution of S(L) satisfies: ; And the second derivative is: ; The function f(L) represents the mapping relationship between the longitude and latitude of the collected sample points; since the cubic spline function S(L) is divided into n-1 segments by n sample points, then in the sub-interval [L i-1 , L i ], the cubic spline function can be denoted as S i(L). Since S(L) is a polynomial of degree not higher than three, its second derivative is a linear function or a constant, then in the subinterval [L i-1 , L i ] for any L, it satisfies: ; wherein, .

[0024] Integrating the above equation twice continuously and using the interpolation conditions S i (L i-1 )=B i–1 , S i (L i )=B i to find the integral constants, we have: ; The railway inspection platform comprises a positioning module, a control module, a holder, and a camera. The positioning module is configured to obtain the three-dimensional coordinates of the UAV. The control module is configured to control the UAV to automatically cruise according to a UAV flight path model. The holder is configured to connect the UAV and the camera, and fix the camera on the UAV, so as to increase the camera shooting range while maintaining the stability of the camera.

[0025] The camera is configured to collect video data along the railway, and shoot the railway live from a bird's eye view, so as to provide reference data for fault diagnosis of the railway line.

[0026] The positioning module comprises a ground positioning module and a sky positioning module. The ground positioning module is fixedly arranged on the ground, and is configured to continuously receive satellite signals to calculate the three-dimensional coordinates of the ground positioning module, and transmit the relevant position information to the sky positioning module. The sky positioning module is arranged on the UAV, and is configured to calculate the three-dimensional coordinates of the UAV in combination with the GPS information and the position information provided by the ground positioning module.

[0027] The above only describes the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A railway inspection method based on drones, characterized in that: The UAV performs railway inspection based on the railway inspection platform, and the railway inspection method includes: Establish a UAV flight path model for planning UAV flight paths; The UAV flight path model includes the flight path altitude H i Function, flight path longitude L i With latitude B i function; The flight path altitude function is determined using the slope of the railway line and the height of on-site obstacles; The flight path longitude and latitude functions are determined using a cubic spline interpolation method.

2. The railway inspection method based on drone according to claim 1, characterized in that: The determination using the railway line slope and on-site obstacle height includes: Step S1: Preliminary inspection of the height of obstacles on the railway site; Step S2: Measure the ground elevation information and the height information of the on-site obstacles based on RTK; Step S3: Determine the altitude of the UAV flight path.

3. The railway inspection method based on drone according to claim 2, characterized in that: The step S3 is specifically as follows: Assume that the ground altitude is H0 and the obstacle height is ΔH, then the altitude of the drone's flight path is H i = H0+ΔH.

4. The railway inspection method based on drone according to claim 1, characterized in that: The determination using the cubic spline interpolation method includes: Step S1: Obtain the coordinate values ​​of the starting point, end point and interval sampling points of the inspection section; Step S2: Based on the above coordinate values, interpolation conditions, continuity conditions and boundary conditions, a cubic spline interpolation function S is established. i (L).

5. The railway inspection method based on drone according to claim 1, characterized in that: The railway inspection platform includes a positioning module, a control module, a pan / tilt platform, and a camera; The positioning module is used to obtain the three-dimensional coordinates of the drone; The control module is used to control the automatic cruising of the UAV according to the UAV flight path model; The gimbal is used to connect the drone and the camera; The camera is used to collect video data along the railway.

6. The railway inspection method based on drone according to claim 5, characterized in that: The positioning module includes a ground positioning module and a sky positioning module; The ground positioning module is fixedly arranged on the ground and is used to continuously receive satellite signals to calculate the three-dimensional coordinates of its location and transmit the relevant position information to the sky positioning module; The sky positioning module is set on the drone and calculates the three-dimensional coordinates of the drone by combining GPS information and position information provided by the ground positioning module.

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