CN105333818A - 3D space measurement method based on monocular camera - Google Patents

Abstract

The present invention provides a 3D space measurement method based on a monocular camera, comprising: respectively focusing on the points to be measured and auxiliary test points on the ground to obtain corresponding imaging parameters, wherein the auxiliary test points are located on the projection line of the optical axis of the camera on the ground In the above, the object distance between the point to be measured and the auxiliary test point is different, and the camera installation parameters of the two imaging remain unchanged; according to the imaging parameters of the point to be measured and the auxiliary test point, the correlation calculation is performed on the two imaging to obtain the relative distance of the point to be measured Coordinates, the reference coordinate system of the relative coordinates is, the projection of the fulcrum of the camera on the ground is the origin, the vertical line between the fulcrum and the ground is the Y axis, the projection of the optical axis of the camera along the ground is the X axis, and the X axis and the The direction perpendicular to the Y axis is the Z axis. The invention uses the internal parameters of the monocular camera to calculate the spatial coordinates of the point to be measured, without measuring the installation parameters of the camera and calibrating the calibration object, which saves the cost and simplifies the operation.

Description

3D space measurement method based on monocular camera

technical field

The invention relates to the field of video monitoring, in particular to a 3D space measurement method based on a monocular camera.

Background technique

Monocular cameras cannot form 3D vision through a single shot. When there is no reference object of predicted size for auxiliary measurement, and the height of the camera erection and the angle between the central axis of the lens and the ground are not known, the relative coordinates between the object to be photographed and the installation point of the camera cannot be measured.

In the prior art, when a monocular camera takes a single shot, by shooting a reference object with a predetermined size, the object size and The proportional relationship between the pixels of the image captured by the camera. Then, in the subsequent shooting, without changing the installation parameters of the camera, it is only necessary to calculate the actual size of the object according to the number of pixels occupied by the object to be photographed. Through the angle between the camera and the ground and the height of the erection pole, the relative coordinates between the object to be photographed and the camera can be calculated.

Through the above process, it can be seen that a single shot of a monocular camera requires many external conditions, and requires camera installation data, such as the height of the erection pole, the angle between the camera and the ground; calibration objects are required, and manual auxiliary calibration calculations are required to obtain conversion parameters ;The installation parameters of the camera cannot be changed in the subsequent use, otherwise it must be re-calibrated, and the adaptability is not good.

Or in the prior art, binocular cameras shoot the same object, or a monocular camera shoots the same object at two different positions and angles, and realize 3D visual perception through different positions in the image. However, two cameras must be used, or a moving guide rail and a driving device must be provided for a single camera, and the cost is relatively high.

Contents of the invention

In view of this, the present invention provides a method for measuring 3D space based on a monocular camera, the method comprising:

Focus on the point to be measured and the auxiliary test point on the ground respectively, and obtain corresponding imaging parameters, wherein the auxiliary test point is located on the projection line of the optical axis of the camera on the ground, and the object distance between the point to be measured and the auxiliary test point is different, and the camera installation parameters of the two imaging remain unchanged;

According to the imaging parameters of the point to be measured and the auxiliary test point, the two images are correlated and calculated to obtain the relative coordinates of the point to be measured. The reference coordinate system of the relative coordinates is that the fulcrum of the camera is installed on the ground The projection of the fulcrum is the origin, the vertical line between the fulcrum and the ground is the Y axis, the projection of the optical axis of the camera along the ground is the X axis, and the direction perpendicular to the X and Y axes is the Z axis.

The present invention also provides a 3D space measuring device based on a monocular camera, the device comprising:

The imaging parameter acquisition unit is used to respectively focus on the point to be measured and the auxiliary test point on the ground to obtain corresponding imaging parameters, wherein the auxiliary test point is located on the projection line of the optical axis of the camera on the ground, and the point to be measured is connected to the projection line of the ground. The object distance of the auxiliary test points is different, and the camera installation parameters of the two imaging are unchanged;

The relative coordinate calculation unit is used to perform correlation calculation on the two imaging according to the imaging parameters of the point to be measured and the auxiliary test point to obtain the relative coordinates of the point to be measured, and the reference coordinate system of the relative coordinates is , taking the projection of the camera installation fulcrum on the ground as the origin, taking the vertical line between the fulcrum and the ground as the Y axis, taking the projection of the camera optical axis along the ground as the X axis, and taking the direction perpendicular to the X and Y axes as the Z axis.

The present invention uses the internal parameters of the monocular camera to calculate the spatial relative coordinates of the points to be measured without measuring the installation parameters of the camera and calibrating the calibration object, saving manpower, material resources and time costs, and simplifying the operation process.

Description of drawings

Fig. 1 is a schematic diagram of the logical structure and basic hardware environment of 3D space measurement based on a monocular camera in an embodiment of the present invention.

Fig. 2 is a flowchart of a 3D space measurement method based on a monocular camera in an embodiment of the present invention.

Figure 3 is a schematic diagram of the installation of a monocular camera.

Fig. 4 is a schematic diagram of optical imaging in an embodiment of the present invention.

Fig. 5 is a schematic diagram of the image height of the imaging point in the Y-axis direction of the image acquisition sensor in an embodiment of the present invention.

Fig. 6 is a schematic diagram of the principle of lens imaging.

Fig. 7 is a schematic diagram of the image height of the imaging point in the Z-axis direction of the image acquisition sensor in an embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings.

The present invention provides a 3D space measurement device based on a monocular camera. The software implementation is taken as an example for description below, but the present invention does not exclude other implementations such as hardware or logic devices. As shown in FIG. 1 , the hardware environment in which the device operates includes CPU, memory, non-volatile memory and other hardware. The device acts as a virtual device on a logical level, which runs through the CPU. The device includes an imaging parameter acquisition unit and a relative coordinate calculation unit. Please refer to Fig. 2, the use and operation process of this device comprises the following steps:

Step 101, the imaging parameter acquisition unit focuses on the point to be measured and the auxiliary test point on the ground respectively, and obtains corresponding imaging parameters, wherein the auxiliary test point is located on the projection line of the optical axis of the camera on the ground, and the point to be measured and the auxiliary test point are located on the projection line of the ground. The object distance of the auxiliary test points is different, and the camera installation parameters of the two imaging are unchanged;

Step 102, the relative coordinate calculation unit performs correlation calculation on the two imaging according to the imaging parameters of the point to be measured and the auxiliary test point, and obtains the relative coordinates of the point to be measured, and the reference coordinate system of the relative coordinates is , taking the projection of the camera installation fulcrum on the ground as the origin, taking the vertical line between the fulcrum and the ground as the Y axis, taking the projection of the camera optical axis along the ground as the X axis, and taking the direction perpendicular to the X and Y axes as the Z axis.

The present invention performs imaging on the points to be measured and auxiliary test points without changing the installation parameters (position, height, pan-tilt angle, etc.) of the monocular camera, and performs correlation calculation on the two imaging according to the imaging parameters to obtain the points to be measured space coordinates. The specific process is as follows.

As shown in Figure 3, the monocular camera is vertically installed at point E through a pole. Establish a reference coordinate system with point E as the origin, and calculate the position coordinates of the points to be measured relative to the coordinate system. The X-axis of the coordinate system is the projection of the optical axis direction of the camera on the ground, the Y-axis is the direction of the pole, and the Z-axis is perpendicular to the XY plane. The intersection A of the object AD and the ground in the figure is the point to be tested, and the point B on the ground is the auxiliary test point, which is on the projection of the optical axis of the camera along the ground.

As shown in Figure 4, the simple structure of the camera is shown in the figure, where the optical center of the lens is the virtual optical center formed by the multiple lenses of the camera lens, and the distance between the optical center of the lens and the fulcrum of the camera (along the direction of the optical axis of the camera) is r, there may be some changes in the two imaging before and after. is the angle between the optical axis of the camera and the ground.

Without changing the camera installation parameters (height, optical axis angle, direction), use the monocular camera to focus on point A and point B respectively, and obtain the corresponding imaging parameters. The imaging point of point A on the image sensor is point a, and the imaging point of point B on the image sensor is point b. Both the image and the object are projected on a plane perpendicular to the optical axis for easy calculation and derivation. P ₁ is the primary imaging object plane, that is, the object plane where point A is located; P ₂ is the secondary imaging object plane, that is, the object plane where point B is located. Thus, the primary imaging image distance V ₁ , focal length F ₁ and the distance r ₁ between the lens optical center and the mounting fulcrum; the secondary imaging image distance V ₂ , focal length F ₂ and the distance r ₂ between the lens optical center and the mounting fulcrum .

The image height is calculated according to the position of the imaging point in the image sensor, as shown in Figure 5. The upper imaging point in the figure is point b, and the lower imaging point is point a. According to the proportional relationship between the physical size and the number of corresponding pixel points along the physical size direction, the physical size (image height) of the imaging point along the XY plane is calculated. In the figure, S is the physical size of the effective pixel range of the image sensor along the XY plane; S ₁ is the vertical distance from point a to the horizontal line of the center of the image sensor, that is, the imaging height of point A; S ₂ is the vertical distance from point b to the horizontal line of the center of the image sensor , that is, the imaging height of point B.

Through the above process, obtain the image distance V ₁ , focal length F ₁ , image height S ₁ corresponding to point A, and the distance r ₁ between the optical center of the lens and the mounting fulcrum; obtain the image distance V ₂ , focal length F ₂ , and image height corresponding to point B S ₂ and the distance r ₂ between the optical center of the lens and the mounting fulcrum. The relative coordinates of the point A to be measured are obtained by performing correlation calculation on the two imaging parameters according to the above imaging parameters. The calculation process will be described in detail below in conjunction with FIG. 4 .

According to the Gaussian imaging formula

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Calculate the object distance U ₁ of point A and the object distance U ₂ of point B respectively

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Thus, the distance (along the direction of the optical axis) between the two imaging object planes is:

$\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

According to the lens imaging principle shown in Figure 6

Find the object heights of point A and point B relative to the optical axis of the camera, that is, the values of n and k in Figure 4

$\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

According to the geometric relationship in Figure 4, it can be concluded that

$\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{\sqrt{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

Substituting formula (4), formula (6) and formula (7) into formula (8), we get

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\sqrt{{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

Similarly, it can be obtained from the geometric relationship

$\frac{\mathrm{<span\; class="notranslate">\; no</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>\frac{\sqrt{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

Substituting formula (4), formula (6) and formula (7) into formula (10), we get

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}{\sqrt{{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

therefore,

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}{\sqrt{{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

L is the X-axis coordinate of the point A to be measured, denoted as A _x .

The distance between point A on the object plane P ₁ and the plane perpendicular to the ground with the optical axis is A _z , and the distance between the image point a of point A and the plane perpendicular to the ground with the optical axis is a _z , then

$\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

Similarly, according to the proportional relationship between the physical size and the number of corresponding pixels along the physical size direction, the physical size (image height a _z ) of the imaging point a along the Z-axis direction is calculated. Q in FIG. 7 is the physical size of the effective pixel range of the image sensor along the Z-axis direction.

Substituting formula (2) into formula (13) gives

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 14</span>}<span\; class="notranslate">\; )</span>$

A _z is the Z-axis coordinate of point A to be measured; the Y-axis coordinate A _y of point A is 0. The coordinates of point A (A _x , A _y , A _z ) are the coordinates relative to the preset coordinate system of point E. If the physical coordinates of point E are known, the actual geographic coordinates of point A can be added to the coordinates of point E The calculated relative coordinates of point A are calculated.

It can be seen that through two or more imaging of the monocular camera, and using the internal data of the monocular camera, such as image distance, focal length, and image sensor size, the associated calculation of the imaging parameters can realize the accuracy of the point to be measured. position measurement. In this process, there is no need to measure the installation parameters of the camera and calibrate the calibration object, which saves manpower, material resources and time costs, and simplifies the operation process.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (8)

1. A3D space measurement method based on a monocular camera is characterized by comprising the following steps:

focusing a point to be tested and an auxiliary test point on the ground respectively to obtain corresponding imaging parameters, wherein the auxiliary test point is positioned on a projection line of an optical axis of a camera on the ground, the object distance between the point to be tested and the auxiliary test point is different, and the camera installation parameters of two times of imaging are unchanged;

and performing correlation calculation on the two imaging according to the imaging parameters of the point to be measured and the auxiliary test point to obtain a relative coordinate of the point to be measured, wherein a reference coordinate system of the relative coordinate is that the projection of a camera mounting fulcrum on the ground is taken as an origin, the perpendicular line of the fulcrum and the ground is taken as a Y axis, the projection of the camera optical axis along the ground is taken as an X axis, and the direction perpendicular to the X axis and the Y axis is taken as a Z axis.

2. The method of claim 1, wherein:

x-axis coordinate A in the relative coordinate of the point to be measured_xComprises the following steps:

$A_x=\frac{(\frac{V_1{F}_1}{V_1-F_1}+r_1)(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)+\left(\frac{F_1{S}_1}{V_1-F_1}\right)(\frac{S_1{F}_1}{V_1-F_1}+\frac{S_2{F}_2}{V_2-F_2})}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

wherein,

V₁the image distance of the point to be measured is taken as the image distance of the point to be measured;

F₁the focal length of the point to be measured is taken as the focal length of the point to be measured;

S₁the image height of the point to be measured along the XY plane is taken as the image height;

r₁the distance (along the optical axis of the camera) between the optical center of the lens of the point to be measured and the mounting pivot of the camera;

V₂the image distance of the auxiliary test point is used as the image distance of the auxiliary test point;

F₂the focal distance of the auxiliary test point is;

S₂the image height of the auxiliary test point along the XY plane is taken as the image height;

r₂as lens light of the auxiliary test pointThe distance (along the optical axis of the camera) between the optical center and the mounting pivot of the camera.

3. The method of claim 1, wherein:

z-axis coordinate A in the relative coordinate of the point to be measured_zComprises the following steps:

$A_z=\frac{F_1{a}_z}{V_1-F_1}$

wherein,

V₁the image distance of the point to be measured is taken as the image distance of the point to be measured;

F₁the focal length of the point to be measured is taken as the focal length of the point to be measured;

a_zand the image height of the point to be measured along the Z-axis direction is obtained.

4. The method of claim 2, wherein:

a is described_xThe specific calculation process is as follows:

the object distance U of the point to be measured₁And the object distance U of the auxiliary test point₂Respectively as follows:

$U_1=\frac{V_1{F}_1}{V_1-F_1}$

$U_2=\frac{V_2{F}_2}{V_2-F_2}$

thereby obtaining object planes P imaged twice₁And P₂The distance (in the optical axis direction) j + m therebetween is:

$j+m=(U_1+r_1)-(U_2+r_2)=\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+(r_1-r_2)$

respectively solving the object height n of the point to be tested, which is vertical to the optical axis of the camera, and the object height k of the auxiliary test point, which is vertical to the optical axis of the camera:

$n=\frac{U_1}{V_1}*S_1=\frac{F_1{S}_1}{V_1-F_1}$

$k=\frac{U_2}{V_2}*S_2=\frac{F_2{S}_2}{V_2-F_2}$

respectively substituting the above parameters into a geometric formulaAnd $\frac{n}{L_2}=\frac{\sqrt{{(j+m)}^2+{(k+n)}^2}}{n+k},$ can obtain the product

$L_1=\frac{(\frac{V_1{F}_1}{V_1-F_1}+r_1)(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

$L_2=\frac{\left(\frac{F_1{S}_1}{V_1-F_1}\right)(\frac{S_1{F}_1}{V_1-F_1}+\frac{S_2{F}_2}{V_2-F_2})}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

A_x＝L₁+L₂。

5. A monocular camera-based 3D spatial measuring device, comprising:

the imaging parameter acquisition unit is used for respectively focusing a point to be measured and an auxiliary test point on the ground to acquire corresponding imaging parameters, wherein the auxiliary test point is positioned on a projection line of a camera optical axis on the ground, the object distance between the point to be measured and the auxiliary test point is different, and the camera installation parameters of the two times of imaging are unchanged;

and the relative coordinate calculation unit is used for performing correlation calculation on the two imaging according to the imaging parameters of the point to be measured and the auxiliary test point to obtain the relative coordinate of the point to be measured, wherein the reference coordinate system of the relative coordinate is that the projection of the camera installation fulcrum on the ground is taken as an origin, the perpendicular line of the fulcrum and the ground is taken as a Y axis, the projection of the camera optical axis along the ground is taken as an X axis, and the direction perpendicular to the X axis and the Y axis is taken as a Z axis.

6. The apparatus of claim 5, wherein:

the relative coordinate calculation unit calculates the relative coordinateX-axis coordinate A of measuring point_xComprises the following steps:

$A_x=\frac{(\frac{V_1{F}_1}{V_1-F_1}+r_1)(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)+\left(\frac{F_1{S}_1}{V_1-F_1}\right)(\frac{S_1{F}_1}{V_1-F_1}+\frac{S_2{F}_2}{V_2-F_2})}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

wherein,

V₁the image distance of the point to be measured is taken as the image distance of the point to be measured;

F₁the focal length of the point to be measured is taken as the focal length of the point to be measured;

S₁the image height of the point to be measured along the XY plane is taken as the image height;

r₁the distance (along the optical axis of the camera) between the optical center of the lens of the point to be measured and the mounting pivot of the camera;

V₂the image distance of the auxiliary test point is used as the image distance of the auxiliary test point;

F₂the focal distance of the auxiliary test point is;

S₂the image height of the auxiliary test point along the XY plane is taken as the image height;

r₂the distance (along the optical axis of the camera) between the optical center of the lens of the auxiliary test point and the mounting pivot of the camera.

7. The apparatus of claim 5, wherein:

the relative coordinate calculation unit calculates the Z-axis coordinate A of the point to be measured_zComprises the following steps:

$A_z=\frac{F_1{a}_z}{V_1-F_1}$

wherein,

V₁the image distance of the point to be measured is taken as the image distance of the point to be measured;

F₁the focal length of the point to be measured is taken as the focal length of the point to be measured;

a_zand the image height of the point to be measured along the Z-axis direction is obtained.

8. The apparatus of claim 6, wherein:

the relative coordinate calculation unit calculates the A_xThe specific process comprises the following steps:

the object distance U of the point to be measured₁And the object distance U of the auxiliary test point₂Respectively as follows:

$U_1=\frac{V_1{F}_1}{V_1-F_1}$

$U_2=\frac{V_2{F}_2}{V_2-F_2}$

thereby obtaining object planes P imaged twice₁And P₂The distance (in the optical axis direction) j + m therebetween is:

$j+m=(U_1+r_1)-(U_2+r_2)=\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+(r_1-r_2)$

respectively solving the object height n of the point to be tested, which is vertical to the optical axis of the camera, and the object height k of the auxiliary test point, which is vertical to the optical axis of the camera:

$n=\frac{U_1}{V_1}*S_1=\frac{F_1{S}_1}{V_1-F_1}$

$k=\frac{U_2}{V_2}*S_2=\frac{F_2{S}_2}{V_2-F_2}$

respectively substituting the above parameters into a geometric formulaAnd $\frac{n}{L_2}=\frac{\sqrt{{(j+m)}^2+{(k+n)}^2}}{n+k},$ can obtain the product

$L_1=\frac{(\frac{V_1{F}_1}{V_1-F_1}+r_1)(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

$L_2=\frac{\left(\frac{F_1{S}_1}{V_1-F_1}\right)(\frac{S_1{F}_1}{V_1-F_1}+\frac{S_2{F}_2}{V_2-F_2})}{\sqrt{{(\frac{V_1{F}_1}{V_1-F_1}-\frac{V_2{F}_2}{V_2-F_2}+r_1-r_2)}^2+{(\frac{F_1{S}_1}{V_1-F_1}+\frac{F_2{S}_2}{V_2-F_2})}^2}}$

A_x＝L₁+L₂。