Grid type measuring method for elevation of surface mine platform

Abstract

The invention discloses a surface mine platform elevation grid type measuring method, which comprises the following steps of: constructing an earth coordinate system in a surface mine surrounding area, determining a coordinate value of an unmanned aerial vehicle relative to the earth coordinate system during aerial survey, and setting the unmanned aerial vehicle to move according to a curve route, in the process of moving along the curve route, a mine surface image of the route is shot, slope coordinates and platform coordinates of the mine surface relative to an earth coordinate system are obtained, an intermittent mine three-dimensional model formed by the curve route is constructed, and the unmanned aerial vehicle is regulated and controlled to have an intersection point between two adjacent curve routes; supplementing the mine surface information obtained by the next curve route into the intermittent mine three-dimensional model until the intermittent mine three-dimensional model with uniformly spaced mine surface images is formed; performing interpolation supplement on the two adjacent mine surface images and the corresponding slope coordinates and platform coordinates until a complete surface mine three-dimensional model is formed; according to the method, the modeling time of the three-dimensional model containing the height of the platform is short, and the precision is high.

Description

Technical Field

[0001] This invention relates to the field of open-pit mine modeling elevation technology, specifically to a grid-based method for determining the elevation of an open-pit mine platform. Background Technology

[0002] Bench-type mining in open-pit mines effectively controls slope stability by dividing the ore into horizontal layers, forming a stepped structure. When the slope angle is designed appropriately, it ensures mining safety while reducing stripping workload and costs. Excessively large slope angles can easily trigger landslides and collapses; conversely, excessively small slope angles increase stripping costs. Bench-type structures facilitate independent operations such as drilling, blasting, and loading, improving mining efficiency. For example, working platforms allow for blasting operations, safety platforms ensure the safety of personnel and equipment, and cleaning platforms facilitate the removal of waste rock. Different rock structures may contain defects such as joints and fissures; bench-type mining can reduce the risk of stress concentration in the rock mass and decrease the probability of landslides through layered control. To further monitor open-pit mines comprehensively and reduce damage caused by landslides and other disasters, the commonly used solution is to construct a three-dimensional simulated mine model identical to the open-pit mine. The process involves using drones to capture images of the open-pit mine, generating a three-dimensional mine image, marking different platform heights on the three-dimensional mine image, and then replicating the simulated three-dimensional mine image one-to-one with the actual open-pit mine.

[0003] However, when marking different platform heights on three-dimensional mine images, most of the time, drones are used to measure the different platform heights by flying around at different heights. This takes a lot of time, and complex weather conditions (such as strong winds and low temperatures) can exacerbate flight attitude disturbances, leading to instability risks. It is difficult for drones to maintain the same height for large-diameter circular flights. Therefore, when the weather is unstable, the drone will fluctuate up and down, which increases the error in the measured platform height. Summary of the Invention

[0004] The purpose of this invention is to provide a grid-based method for determining the elevation of open-pit mine platforms. This method addresses the problem that in existing technologies, when different platform heights are marked on three-dimensional mine images, drones are often used to measure these heights by flying around at different altitudes. However, it is difficult for drones to maintain a consistent altitude for large-diameter circling flights. Consequently, in unstable weather conditions, the drones may fluctuate, leading to increased errors in the measured platform heights.

[0005] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A method for determining the elevation grid of an open-pit mine platform includes the following steps: Step 100: Construct a geodetic coordinate system within the area surrounded by the open-pit mine, determine the starting position of the UAV during its first aerial survey of the open-pit mine, and determine the coordinate values ​​of the UAV relative to the geodetic coordinate system during the aerial survey. Step 200: Set the UAV to move along a curved route, and take pictures of the mine surface along the curved route during the movement, and obtain the slope coordinates and platform coordinates of the mine surface relative to the Earth coordinate system. Construct a discontinuous three-dimensional mine model formed by the curved route. On the discontinuous three-dimensional mine model, vertical grid lines are formed on both sides of each mine surface image, and horizontal grid lines are formed on the same elevation platform of each mine platform on the discontinuous three-dimensional mine model. Step 300: Adjust the horizontal interval between the next curved flight path of the UAV and the previous curved flight path, and adjust the UAV to fly along the curved flight path so that there is an intersection point between two adjacent curved flight paths of the UAV. Add the mineral surface information obtained by the next curved flight path to the discontinuous mine 3D model until a discontinuous mine 3D model with uniform mineral surface image interval is formed. Step 400: Interpolate the two adjacent mine surface images at the same height, as well as the slope coordinates and platform coordinates corresponding to the two adjacent mine surface images, to form a complete three-dimensional model of the open-pit mine.

[0006] As a preferred embodiment of the present invention, in step 100, the origin of the Earth coordinate system is preset, the UAV is moved to the origin of the Earth coordinate system, and the GPS coordinates of the UAV at this time are determined and set as the origin of the Earth coordinate system. Select the starting position for the first aerial survey of the UAV, and convert the UAV's real-time GPS coordinates into the UAV's real-time coordinate position in the Earth coordinate system.

[0007] As a preferred embodiment of the present invention, in step 200, the UAV flies along a sinusoidal path to form a curved flight path, and while flying along the curved flight path, the UAV takes pictures of the open-pit mine surface and obtains the latitude and longitude of the inclined surface measurement point in the open-pit mine surface image relative to the UAV, as well as the latitude and longitude of the mine platform measurement point relative to the UAV. The latitude and longitude of the inclined plane measurement points in the open-pit mine surface image relative to the UAV, and the latitude and longitude of the mine platform measurement points relative to the UAV, are converted into three-dimensional coordinates relative to the Earth coordinate system, forming a dense point three-dimensional model within the Earth coordinate system. Images of the open-pit mine face are stitched together into a dense point 3D model to form a discontinuous 3D mine model containing images of the mine face.

[0008] As a preferred embodiment of the present invention, the method for obtaining the latitude and longitude of the inclined surface measurement point relative to the UAV within the open-pit mine surface image, and the latitude and longitude of the mine platform measurement point relative to the UAV, is as follows: A body coordinate system is constructed using the UAV itself. A test laser is emitted from a laser emission point on the UAV itself. The tilt angle between the test laser and the XY plane of the body coordinate system, as well as the three-dimensional coordinate values ​​of the laser emission point relative to the body coordinate system, are determined. The test laser is received by the UAV after being reflected by the surface of the open-pit mine, so as to determine the one-way length of the test laser. Based on the single-journey length of the test laser, the tilt angle of the test laser to the XY plane of the machine coordinate system, and the latitude and longitude of the laser emission point in the machine coordinate system, the latitude and longitude of the reflection point of the test laser on the mine surface in the open-pit mine corresponding to the reflection point in the machine coordinate system are determined. Based on the latitudinal variation pattern of the reflection points, the reflection points of the open-pit mine are divided into mine slope reflection points and mine platform reflection points. Among them, reflection points with latitude values ​​at the same height are designated as mine platform reflection points, and reflection points with latitude values ​​that differ greatly from mine platform reflection points are designated as mine slope reflection points.

[0009] As a preferred embodiment of the present invention, the method for converting the latitude and longitude of the reflection points of the mine slope and the reflection points of the mine platform in the open-pit mine surface image into three-dimensional coordinates relative to the Earth coordinate system is as follows: Determine the coordinate transformation matrix for converting the GPS coordinates of the UAV body into three-dimensional coordinates of Earth coordinates; The latitude and longitude values ​​of the mine slope reflection point relative to the UAV are converted into the three-dimensional coordinates of the mine slope reflection point in the Earth coordinate system according to the coordinate transformation matrix. The latitude and longitude values ​​of the mine platform reflection point relative to the UAV are also converted into the three-dimensional coordinates of the mine platform reflection point in the Earth coordinate system according to the coordinate transformation matrix. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point in the Earth coordinate system, obtained by the UAV monitoring along the curved route, are integrated into the Earth coordinate system. After data fitting of the three-dimensional coordinates of the mine platform reflection point and the mine slope reflection point, a dense point three-dimensional model containing only point coordinates is formed.

[0010] As a preferred embodiment of the present invention, the method for stitching together captured images of the open-pit mine face into a dense point 3D model to form a discontinuous 3D mine model containing the mine face images is as follows: The system synchronously triggers the drone to capture images of the open-pit mine surface, the drone to emit test lasers, and the drone to obtain its current GPS coordinates. The three-dimensional coordinate values ​​of the mine slope reflection point and the mine platform reflection point obtained from the drone's test lasers emitted during each open-pit mine surface image capture are integrated into the same monitoring set in the Earth coordinate system. The three-dimensional coordinate values ​​of the mine slope reflection points and mine platform reflection points extracted from the same monitoring set are integrated into the Earth coordinate system. After image processing of the open-pit mine surface images in the set, the open-pit mine surface images are pasted into the dense point three-dimensional model according to the image features and coordinate value alignment method to generate a discontinuous mine three-dimensional model.

[0011] As a preferred embodiment of the present invention, the method for pasting the open-pit mine face image into the dense point 3D model according to the image feature and coordinate value alignment is as follows: The images of the open-pit mine face from two adjacent monitoring sets, captured by the drone along a curved flight path, are stitched together sequentially. The stitched open-pit mine face image is binarized to identify the edges corresponding to the mine platform in the open-pit mine face image; Determine the monitoring set corresponding to the open-pit mine face image, and use the coordinate values ​​of the reflection points of the mine platform in the monitoring set as indexes to paste the corresponding edges of the mine platform in the open-pit mine face image into the dense point 3D model to form a discontinuous mine 3D model containing mine coordinate information and image information. Vertical grid lines are formed on both sides of each mine face image in the discontinuous 3D mine model, and horizontal grid lines are formed on the same elevation platform of each mine platform in the discontinuous 3D mine model.

[0012] As a preferred embodiment of the present invention, in step 300, the UAV flies around the open-pit mine according to the curved route planned for the first flight, and the flight position of the UAV is determined in real time based on the three-dimensional coordinates of the UAV in the Earth coordinate system. After the drone flies to the end of the curved route planned for the first flight, the drone is controlled to fly according to the next curved route, with overlapping points between two adjacent curved routes; Based on the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured at the overlapping points when the UAV flies the next curved route, corresponding to the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained during the current flight monitoring of the UAV, the error coefficient of the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point is calculated, and the three-dimensional coordinates of all the mine slope reflection points and the mine platform reflection points measured along the current curved route are corrected. The corrected three-dimensional coordinates of the mine slope reflection points and mine platform reflection points, as well as the open-pit mine surface image taken by UAV, are added to the discontinuous mine three-dimensional model. Repeat the above steps until the drone conducts flight monitoring in sequence according to all the planned curved routes, until a discontinuous 3D model of the mine with uniformly spaced images of the mine surface is formed.

[0013] As a preferred embodiment of the present invention, the method for calculating the error coefficient during the current flight monitoring of the UAV is as follows: Determine the same three-dimensional coordinate values ​​of the UAV body in the current curved flight path and in the previous curved flight paths; Determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the previous curved flight path; Calculate the error coefficients on the x-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, the error coefficients on the y-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and the error coefficients on the z-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained by the UAV along the current curved flight path are corrected using the above error coefficients and then added into the discontinuous mine three-dimensional model.

[0014] As a preferred embodiment of the present invention, in step 400, there are mining platforms with the same platform height range on the discontinuous three-dimensional model of the mine with uniformly spaced mine surface images. Identify the reflection points of the discontinuous three-dimensional mine model located on the same mine platform in sequence from top to bottom or bottom to top. Based on the three-dimensional coordinates of the reflection points of two adjacent mining platforms in the Earth coordinate system, the coordinate values ​​of the area between the two adjacent mining platforms are interpolated and supplemented according to the interpolation method until the area between all mining platforms in the same mining height range is filled to form a complete mining platform. Based on the pixel features of open-pit mine face images of two adjacent mining platforms, pixel interpolation is performed on the regions between the two adjacent open-pit mine face images according to the interpolation method to form a complete 3D mine model.

[0015] Compared with the prior art, the present invention has the following advantages: This invention uses unmanned aerial vehicles (UAVs) for aerial surveying. Instead of the conventional method of circling and monitoring the surface of an open-pit mine at the same altitude, or circling and monitoring the slope and platform heights of the open-pit mine at the same altitude, the UAV conducts aerial surveys along a sinusoidal flight path. It monitors the mine surface cyclically from bottom to top and from top to bottom. By repeatedly conducting aerial surveys along sinusoidal flight paths with lateral intervals, it can obtain laterally equidistant surface images and coordinates of the open-pit mine. By interpolating two adjacent surface images and coordinates within the same altitude range, it can obtain the overall three-dimensional model of the open-pit mine and the platform height of each step. This results in a short modeling time for a three-dimensional model that includes the platform heights. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of the mesh size determination method according to an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, this invention provides a method for determining the elevation grid of an open-pit mine platform, comprising the following steps: Step 100: Construct a geodetic coordinate system within the area surrounded by the open-pit mine, determine the starting position of the UAV during its first aerial survey of the open-pit mine, and determine the coordinate values ​​of the UAV relative to the geodetic coordinate system during the aerial survey. Step 200: Set the UAV to move along a curved route, and take pictures of the mine surface along the curved route during the movement, and obtain the slope coordinates and platform coordinates of the mine surface relative to the Earth coordinate system. Construct a discontinuous three-dimensional mine model formed by the curved route. On the discontinuous three-dimensional mine model, vertical grid lines are formed on both sides of each mine surface image, and horizontal grid lines are formed on the same elevation platform of each mine platform on the discontinuous three-dimensional mine model. Step 300: Adjust the horizontal interval between the next curved flight path of the UAV and the previous curved flight path, and adjust the UAV to fly along the curved flight path so that there is an intersection point between two adjacent curved flight paths of the UAV. Add the mineral surface information obtained by the next curved flight path to the discontinuous mine 3D model until a discontinuous mine 3D model with uniform mineral surface image interval is formed. Step 400: Interpolate the two adjacent mine surface images at the same height, as well as the slope coordinates and platform coordinates corresponding to the two adjacent mine surface images, to form a complete three-dimensional model of the open-pit mine.

[0020] Existing methods for determining the platform elevation of open-pit mines mostly involve one or a combination of UAV aerial surveying, GNSS large-scale rapid data acquisition, and ground laser scanning. This implementation method only uses UAV aerial surveying for preliminary grid-like 3D modeling of the open-pit mine. For data correction and confirmation of platform elevation, further data can be obtained through ground laser scanning or GNSS large-scale rapid data acquisition.

[0021] In this embodiment, when using UAV aerial surveying, the conventional method of circling and monitoring the open-pit mine surface at the same altitude, as well as the slope height and platform height, is not employed. Instead, the UAV is used to conduct aerial surveys along a sinusoidal flight path, cyclically monitoring the mine surface from bottom to top and from top to bottom. By repeatedly conducting aerial surveys along the sinusoidal flight path with lateral intervals, laterally equidistant images and coordinates of the open-pit mine surface can be obtained. By interpolating two adjacent images and coordinates of the open-pit mine surface within the same altitude range, an overall 3D model of the open-pit mine and the platform height of each step can be obtained, resulting in a short modeling time for a 3D model that includes the platform height.

[0022] Furthermore, to avoid the impact of weather conditions on UAV monitoring data, when monitoring the mountain along a sine curve, the UAV may overlap with previous sine curve routes during subsequent flights. An error coefficient is calculated based on the three-dimensional coordinates of these overlapping points to correct the data measured along the current curve route and reduce measurement errors. However, the slope height and platform height measured by flying around at different altitudes do not have intersections, making it impossible to determine whether there is a deviation between the previous and next measurement data and to generate an error coefficient for correction. Therefore, this implementation method has a short modeling time for the platform elevation of the entire open-pit mine and can reduce measurement errors by automatically correcting deviations based on the deviations between the previous and next measurement data at the same measurement location.

[0023] In step 100, the origin of the Earth coordinate system is preset, the UAV is moved to the origin of the Earth coordinate system, and the GPS coordinates of the UAV at this time are determined and set as the origin of the Earth coordinate system.

[0024] Select the starting position for the first aerial survey of the UAV, and convert the UAV's real-time GPS coordinates into the UAV's real-time coordinate position in the Earth coordinate system.

[0025] The Earth coordinate system uses a three-dimensional sphere to define the position on the Earth's surface, enabling the reference of points on the Earth's surface through latitude and longitude. Therefore, when a drone is conducting aerial surveying, it can determine the drone's real-time coordinate position in the Earth coordinate system based on the GPS coordinates measured by the drone's built-in GPS system.

[0026] In addition, when the UAV conducts aerial surveys along a sine curve, it is used to acquire images of the mine surface and the height of the slope and platform of the mine. If the starting point of the UAV is at the bottom of the mine, when the UAV flies from bottom to top along the curve, its real-time coordinate position in the Earth coordinate system can be determined based on the UAV's GPS coordinates. Then, a body coordinate system is constructed with the UAV itself. Based on the latitude and longitude of the slope measurement points and mine platform measurement points measured by the UAV in the body coordinate system, the real-time coordinate positions of the slope measurement points and mine platform measurement points in the Earth coordinate system can be determined. Thus, the height of the slope measurement points and mine platform measurement points relative to the ground can be determined.

[0027] In step 200, the UAV flies along a sinusoidal path to form a curved flight path. While flying along the curved flight path, the UAV takes pictures of the open-pit mine surface and obtains the latitude and longitude of the inclined surface measurement point in the open-pit mine surface image relative to the UAV, as well as the latitude and longitude of the mine platform measurement point relative to the UAV. The latitude and longitude of the inclined plane measurement points in the open-pit mine face image relative to the UAV, and the latitude and longitude of the mine platform measurement points relative to the UAV, are converted into three-dimensional coordinates of the inclined plane measurement points and the mine platform measurement points relative to the Earth coordinate system, forming a dense point three-dimensional model within the Earth coordinate system.

[0028] Images of the open-pit mine face are stitched together into a dense point 3D model to form a discontinuous 3D mine model containing images of the mine face.

[0029] In this embodiment, when the UAV flies along a sine curve, it can simultaneously acquire images of the mine surface and the three-dimensional coordinates of the inclined planes and step platforms on the mine surface relative to the Earth coordinate system. However, since the UAV can only obtain fragments of the mine surface image along the sine curve when flying along the sine curve, only by combining the fragments of the mine surface image with the three-dimensional coordinates of the inclined plane measurement points and the mine platform measurement points relative to the Earth coordinate system, a discontinuous three-dimensional mine model can be obtained, rather than a complete three-dimensional mine model.

[0030] This embodiment, by controlling the drone to fly along multiple sinusoidal flight paths with lateral intervals, can gradually add mine surface image fragments, as well as the corresponding 3D coordinate values ​​of inclined plane measurement points and mine platform measurement points on the discontinuous 3D mine model. Then, by performing difference processing on the mine surface image fragments, inclined plane measurement point 3D coordinate values, and mine platform measurement point 3D coordinate values ​​within the same height range, a simulated complete 3D mine model can be obtained.

[0031] The method for obtaining the latitude and longitude of the inclined surface measurement points relative to the UAV within the open-pit mine surface image, and the latitude and longitude of the mine platform measurement points relative to the UAV, is as follows: A body coordinate system is constructed using the UAV itself. A test laser is emitted from a laser emission point on the UAV itself. The tilt angle between the test laser and the XY plane of the body coordinate system, as well as the three-dimensional coordinates of the laser emission point relative to the body coordinate system, are determined. The test laser is received by the UAV after being reflected by the surface of the open-pit mine, in order to determine the one-way length of the test laser.

[0032] Based on the single-journey length of the test laser, the tilt angle between the test laser and the XY plane of the machine coordinate system, and the latitude and longitude of the laser emission point in the machine coordinate system, the latitude and longitude of the reflection point of the test laser on the mine surface in the open-pit mine corresponding to the reflection point in the machine coordinate system are determined.

[0033] Based on the latitudinal variation of the reflection points, the reflection points of the open-pit mine surface are divided into mine slope reflection points and mine platform reflection points. Among them, reflection points with latitude values ​​at the same height are designated as mine platform reflection points, and reflection points with latitude values ​​that differ greatly from mine platform reflection points are designated as mine slope reflection points.

[0034] This implementation method uses a drone to emit a test laser to determine the latitude and longitude of the reflection point on the surface of the open-pit mine relative to the drone, and then converts the latitude and longitude into three-dimensional coordinates relative to the Earth coordinate system.

[0035] When the laser emission point is placed in the YZ plane of the UAV's body coordinate system, the longitude of the mine platform reflection point and the mine slope reflection point are the same as the longitude of the UAV. Based on the one-way length of the test laser, the tilt angle of the test laser to the XY plane of the body coordinate system and the latitude of the laser emission point in the body coordinate system.

[0036] The method for converting the latitude and longitude of the reflection points of the mine slope and the reflection points of the mine platform in the open-pit mine face image into three-dimensional coordinates relative to the Earth coordinate system is as follows: Determine the coordinate transformation matrix for converting the GPS coordinates of the UAV body into three-dimensional coordinates of Earth coordinates; The latitude and longitude values ​​of the mine slope reflection point relative to the UAV are converted into the three-dimensional coordinates of the mine slope reflection point in the Earth coordinate system according to the coordinate transformation matrix. Similarly, the latitude and longitude values ​​of the mine platform reflection point relative to the UAV are converted into the three-dimensional coordinates of the mine platform reflection point in the Earth coordinate system according to the coordinate transformation matrix. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point in the Earth coordinate system, obtained by the UAV monitoring along the curved flight path, are integrated into the Earth coordinate system. After data fitting of the three-dimensional coordinates of the mine platform reflection point and the mine slope reflection point, a dense point three-dimensional model containing only the point coordinates is formed.

[0037] The method for stitching together images of the open-pit mine face into a dense point 3D model to form a discontinuous 3D mine model containing the mine face images is as follows: The system synchronously triggers the drone to capture images of the open-pit mine surface, the drone to emit test lasers, and the drone to obtain its current GPS coordinates. It integrates the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point in the Earth coordinate system obtained from the drone's test laser emission during each open-pit mine surface image capture into the same monitoring set. The three-dimensional coordinates of the mine slope reflection points and mine platform reflection points extracted from the same monitoring set are integrated into the Earth coordinate system. After image processing of the open-pit mine surface images in the set, they are pasted into the dense point three-dimensional model according to the image features and coordinate value alignment, thus generating a discontinuous mine three-dimensional model.

[0038] This implementation integrates the open-pit mine surface image captured each time, the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point acquired in the Earth coordinate system, and the three-dimensional coordinates of the UAV capturing the open-pit mine surface image in the Earth coordinate system into the same set.

[0039] After integrating the three-dimensional coordinates of the mine slope reflection points and mine platform reflection points into the Earth coordinate system, the features of the step platform in the captured image are obtained. The coordinates of the step platform features are aligned with the coordinates of the mine platform reflection points, thereby generating a discontinuous three-dimensional mine model containing image information.

[0040] The method for pasting an open-pit mine face image into a dense point 3D model, based on the image's features and coordinate value alignment, is as follows: The images of the open-pit mine face from two adjacent monitoring sets, captured by the drone along a curved flight path, are stitched together sequentially. The stitched open-pit mine face image is binarized to identify the edges corresponding to the mine platform in the open-pit mine face image; Determine the monitoring set corresponding to the open-pit mine face image. Using the coordinates of the reflection points of the mine platform in the monitoring set as the index, paste the corresponding edges of the mine platform in the open-pit mine face image into the dense point 3D model to form a discontinuous 3D mine model containing mine coordinate information and image information. Vertical grid lines are formed on both sides of each mine face image in the discontinuous 3D mine model, and horizontal grid lines are formed on the same elevation platform of each mine platform in the discontinuous 3D mine model.

[0041] In step 300, the UAV flies around the open-pit mine along the curved route planned for the first flight, and the UAV's flight position is determined in real time based on the three-dimensional coordinates of the UAV in the Earth coordinate system.

[0042] After the drone flies to the end of the curved route planned for the first flight, the drone is controlled to fly according to the next curved route, with overlapping points between adjacent curved routes.

[0043] Based on the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured at the overlapping points during the next flight of the UAV along the curved route, the error coefficient of the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained during the current flight monitoring of the UAV is calculated, and the three-dimensional coordinates of all the mine slope reflection points and the mine platform reflection points measured along the curved route are corrected.

[0044] The corrected 3D coordinates of the mine slope reflection points and mine platform reflection points, along with aerial images of the open-pit mine surface taken by drones, were added to the discontinuous 3D mine model.

[0045] Repeat the above steps until the drone conducts flight monitoring in sequence according to all the planned curved routes, until a discontinuous 3D model of the mine with uniformly spaced images of the mine surface is formed.

[0046] The method for calculating the error coefficient during the current flight monitoring of the UAV is as follows: Determine the same three-dimensional coordinate values ​​of the UAV body in the current curved flight path and in the previous curved flight paths; Determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the previous curved flight path; Calculate the error coefficients on the x-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, the error coefficients on the y-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and the error coefficients on the z-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained by the UAV along the current curved flight path are corrected using the above error coefficients and then added into the discontinuous mine three-dimensional model.

[0047] Since there are overlapping intersections between the UAV's backward curve route and its forward curve route, by comparing the error coefficients of the three-dimensional coordinate values ​​corresponding to the overlapping intersections, the three-dimensional coordinate values ​​of all mine slope reflection points and mine platform reflection points obtained by the UAV in this aerial survey can be corrected, thereby improving the accuracy of the measurement data.

[0048] In step 400, there are mining platforms with the same platform height range on the discontinuous 3D model of the mine with uniformly spaced mine surface images.

[0049] Identify the reflection points of the discontinuous 3D mine model on the same mine platform in sequence from top to bottom or bottom to top.

[0050] Based on the three-dimensional coordinates of the reflection points of two adjacent mining platforms in the Earth coordinate system, the coordinate values ​​of the area between the two adjacent mining platforms are interpolated and supplemented according to the interpolation method until the area between all mining platforms within the same mining height range is filled to form a complete mining platform.

[0051] Based on the pixel features of open-pit mine face images of two adjacent mining platforms, pixel interpolation is performed on the regions between the two adjacent open-pit mine face images according to the interpolation method to form a complete 3D mine model.

[0052] Commonly used methods for spatial measurement data interpolation include inverse distance weighting (IDW), Kriging, spline interpolation, trend surface analysis, natural neighborhood method, Thiessen polygon method, and radial basis function method (RBF). This implementation method selects different interpolation methods based on the characteristics of image pixel interpolation and coordinate interpolation.

[0053] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A method for determining the elevation grid of an open-pit mine platform, characterized in that, Includes the following steps: Step 100: Construct a geodetic coordinate system within the area surrounded by the open-pit mine, determine the starting position of the UAV during its first aerial survey of the open-pit mine, and determine the coordinate values ​​of the UAV relative to the geodetic coordinate system during the aerial survey. Step 200: Set the UAV to move along a curved route, and take pictures of the mine surface along the curved route during the movement, and obtain the slope coordinates and platform coordinates of the mine surface relative to the Earth coordinate system. Construct a discontinuous three-dimensional mine model formed by the curved route. On the discontinuous three-dimensional mine model, vertical grid lines are formed on both sides of each mine surface image, and horizontal grid lines are formed on the same elevation platform of each mine platform on the discontinuous three-dimensional mine model. Step 300: Adjust the horizontal interval between the next curved flight path of the UAV and the previous curved flight path, and adjust the UAV to fly along the curved flight path so that there is an intersection point between two adjacent curved flight paths of the UAV. Add the mineral surface information obtained by the next curved flight path to the discontinuous mine 3D model until a discontinuous mine 3D model with uniform mineral surface image interval is formed. Step 400: Interpolate the two adjacent mine surface images at the same height, as well as the slope coordinates and platform coordinates corresponding to the two adjacent mine surface images, to form a complete three-dimensional model of the open-pit mine.

2. The method for determining the elevation grid of an open-pit mine platform according to claim 1, characterized in that, In step 100, the origin of the Earth coordinate system is preset, the UAV is moved to the origin of the Earth coordinate system, and the GPS coordinates of the UAV at this time are determined and set as the origin of the Earth coordinate system. Select the starting position for the first aerial survey of the UAV, and convert the UAV's real-time GPS coordinates into the UAV's real-time coordinate position in the Earth coordinate system.

3. The method for determining the elevation grid of an open-pit mine platform according to claim 1, characterized in that, In step 200, the UAV flies along a sinusoidal path to form a curved flight path. While flying along the curved flight path, the UAV takes pictures of the open-pit mine surface and obtains the latitude and longitude of the inclined surface measurement point in the open-pit mine surface image relative to the UAV, as well as the latitude and longitude of the mine platform measurement point relative to the UAV. The latitude and longitude of the inclined plane measurement points in the open-pit mine surface image relative to the UAV, and the latitude and longitude of the mine platform measurement points relative to the UAV, are converted into three-dimensional coordinates relative to the Earth coordinate system, forming a dense point three-dimensional model within the Earth coordinate system. Images of the open-pit mine face are stitched together into a dense point 3D model to form a discontinuous 3D mine model containing images of the mine face.

4. The method for determining the elevation grid of an open-pit mine platform according to claim 3, characterized in that, The method for obtaining the latitude and longitude of the inclined surface measurement points relative to the UAV within the open-pit mine surface image, and the latitude and longitude of the mine platform measurement points relative to the UAV, is as follows: A body coordinate system is constructed using the UAV itself. A test laser is emitted from a laser emission point on the UAV itself. The tilt angle between the test laser and the XY plane of the body coordinate system, as well as the three-dimensional coordinate values ​​of the laser emission point relative to the body coordinate system, are determined. The test laser is received by the UAV after being reflected by the surface of the open-pit mine, so as to determine the one-way length of the test laser. Based on the single-journey length of the test laser, the tilt angle of the test laser to the XY plane of the machine coordinate system, and the latitude and longitude of the laser emission point in the machine coordinate system, the latitude and longitude of the reflection point of the test laser on the mine surface in the open-pit mine corresponding to the reflection point in the machine coordinate system are determined. Based on the latitudinal variation pattern of the reflection points, the reflection points of the open-pit mine are divided into mine slope reflection points and mine platform reflection points. Among them, reflection points with latitude values ​​at the same height are designated as mine platform reflection points, and reflection points with latitude values ​​that differ greatly from mine platform reflection points are designated as mine slope reflection points.

5. The method for determining the elevation grid of an open-pit mine platform according to claim 4, characterized in that, The method for converting the latitude and longitude of the reflection points on the mine slope and the mine platform within the open-pit mine surface image into three-dimensional coordinates relative to the Earth coordinate system is as follows: Determine the coordinate transformation matrix for converting the GPS coordinates of the UAV body into three-dimensional coordinates of Earth coordinates; The latitude and longitude values ​​of the mine slope reflection point relative to the UAV are converted into the three-dimensional coordinates of the mine slope reflection point in the Earth coordinate system according to the coordinate transformation matrix. The latitude and longitude values ​​of the mine platform reflection point relative to the UAV are also converted into the three-dimensional coordinates of the mine platform reflection point in the Earth coordinate system according to the coordinate transformation matrix. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point in the Earth coordinate system, obtained by the UAV monitoring along the curved route, are integrated into the Earth coordinate system. After data fitting of the three-dimensional coordinates of the mine platform reflection point and the mine slope reflection point, a dense point three-dimensional model containing only point coordinates is formed.

6. The method for determining the elevation grid of an open-pit mine platform according to claim 5, characterized in that, The method for stitching together images of the open-pit mine face into a dense point 3D model to form a discontinuous 3D mine model containing the mine face images is as follows: The system synchronously triggers the drone to capture images of the open-pit mine surface, the drone to emit test lasers, and the drone to obtain its current GPS coordinates. The three-dimensional coordinate values ​​of the mine slope reflection point and the mine platform reflection point obtained from the drone's test lasers emitted during each open-pit mine surface image capture are integrated into the same monitoring set in the Earth coordinate system. The three-dimensional coordinate values ​​of the mine slope reflection points and mine platform reflection points extracted from the same monitoring set are integrated into the Earth coordinate system. After image processing of the open-pit mine surface images in the set, the open-pit mine surface images are pasted into the dense point three-dimensional model according to the image features and coordinate value alignment method to generate a discontinuous mine three-dimensional model.

7. The method for determining the elevation grid of an open-pit mine platform according to claim 6, characterized in that, The method for pasting the open-pit mine face image into the dense point 3D model, based on the image features and coordinate value alignment, is as follows: The images of the open-pit mine face from two adjacent monitoring sets, captured by the drone along a curved flight path, are stitched together sequentially. The stitched open-pit mine face image is binarized to identify the edges corresponding to the mine platform in the open-pit mine face image; Determine the monitoring set corresponding to the open-pit mine face image, and use the coordinate values ​​of the reflection points of the mine platform in the monitoring set as indexes to paste the corresponding edges of the mine platform in the open-pit mine face image into the dense point 3D model to form a discontinuous mine 3D model containing mine coordinate information and image information. Vertical grid lines are formed on both sides of each mine face image in the discontinuous 3D mine model, and horizontal grid lines are formed on the same elevation platform of each mine platform in the discontinuous 3D mine model.

8. The method for determining the elevation grid of an open-pit mine platform according to claim 1, characterized in that, In step 300, the UAV flies around the open-pit mine along the curved route planned for the first flight, and the flight position of the UAV is determined in real time based on the three-dimensional coordinates of the UAV in the Earth coordinate system. After the drone flies to the end of the curved route planned for the first flight, the drone is controlled to fly according to the next curved route, with overlapping points between two adjacent curved routes; Based on the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured at the overlapping points when the UAV flies the next curved route, corresponding to the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained during the current flight monitoring of the UAV, the error coefficient of the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point is calculated, and the three-dimensional coordinates of all the mine slope reflection points and the mine platform reflection points measured along the current curved route are corrected. The corrected three-dimensional coordinates of the mine slope reflection points and mine platform reflection points, as well as the open-pit mine surface image taken by UAV, are added to the discontinuous mine three-dimensional model. Repeat the above steps until the drone conducts flight monitoring in sequence according to all the planned curved routes, until a discontinuous 3D model of the mine with uniformly spaced images of the mine surface is formed.

9. The method for determining the elevation grid of an open-pit mine platform according to claim 8, characterized in that, The method for calculating the error coefficient during the current flight monitoring of the UAV is as follows: Determine the same three-dimensional coordinate values ​​of the UAV body in the current curved flight path and in the previous curved flight paths; Determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and determine the three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the previous curved flight path. Calculate the error coefficients on the x-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, the error coefficients on the y-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path, and the error coefficients on the z-axis of the mine slope reflection point and the mine platform reflection point measured by the UAV at this position on the current curved flight path. The three-dimensional coordinates of the mine slope reflection point and the mine platform reflection point obtained by the UAV along the current curved flight path are corrected using the above error coefficients and then added into the discontinuous mine three-dimensional model.

10. The method for determining the elevation grid of an open-pit mine platform according to claim 1, characterized in that... ； In step 400, there are mining platforms with the same platform height range on the discontinuous 3D model of the mine with uniformly spaced ore face images. Identify the reflection points of the discontinuous three-dimensional mine model located on the same mine platform in sequence from top to bottom or bottom to top. Based on the three-dimensional coordinates of the reflection points of two adjacent mining platforms in the Earth coordinate system, the coordinate values ​​of the area between the two adjacent mining platforms are interpolated and supplemented according to the interpolation method until the area between all mining platforms in the same mining height range is filled to form a complete mining platform. Based on the pixel features of open-pit mine face images of two adjacent mining platforms, pixel interpolation is performed on the regions between the two adjacent open-pit mine face images according to the interpolation method to form a complete 3D mine model.

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