Micron-level high-precision automatic three-dimensional positioning device and positioning method based on frequency interference and binocular vision

Abstract

The present invention discloses a micron-level, high-precision, automatic three-dimensional positioning device and method based on frequency interferometry and binocular vision. The device comprises a horizontal and pitch turntable, a ranging module, a binocular vision positioning module, and a multi-station network control system. The binocular vision positioning module of each host synchronously observes a common target sphere and calculates relative orientation parameters between the hosts. Driven by the turntable, the frequency scanning interferometry ranging module of each host sights the same target sphere to obtain high-precision ranging data. Based on the relative orientation parameters and the multi-station ranging data, the three-dimensional spatial coordinates of the target sphere are calculated using a forward intersection adjustment algorithm. The present invention obtains image information of a target sphere with high reflective brightness by adjusting contrast and brightness information. Based on the binocular vision positioning information, the horizontal angle and pitch angle of the point relative to the current ranging module are calculated. The angle information is then transmitted to the turntable to guide the ranging module to sight the corresponding target sphere, thereby achieving automatic target search and aiming functions.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser precision three-dimensional measurement, and specifically relates to a micron-level high-precision automatic three-dimensional positioning device and positioning method based on frequency interference and binocular vision. Background Art

[0002] Frequency scanning interferometry (FSI) has become a key technology in precision industrial measurement due to its superior ranging accuracy, compact design, ability to measure without a cooperating target, and robust adaptability to complex environments. This technology relies on tunable lasers to achieve high-precision absolute distance measurement. Compared to traditional laser interferometry methods, FSI, by using a laser with adjustable wavelength as a light source, not only improves measurement accuracy but also enhances its ability to measure diffuse reflections on non-cooperative targets, thereby maintaining high measurement accuracy and reliability in a wider range of environments.

[0003] In FSI systems, semiconductor tunable lasers are currently the most commonly used type of light source. These lasers vary according to parameters such as their tuning range, bandwidth, and linewidth, so users can choose the most suitable laser model based on specific application requirements. However, despite the many advantages of FSI technology, it also has certain limitations. For example, FSI can only provide absolute distance information to the target that is currently being precisely aimed. This means that in scenarios where multi-point measurements are being made or multiple FSI devices need to work together, the laser beams of each device must be manually adjusted to ensure that they are correctly aligned with their respective measurement targets, which undoubtedly increases the complexity and time cost of the operation. To overcome this limitation, those skilled in the art are exploring new methods and technologies to improve the flexibility and efficiency of FSI systems and make them more suitable for a variety of industrial applications. Summary of the Invention

[0004] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the existing technology and provide a micron-level high-precision automatic three-dimensional positioning device and positioning method based on frequency interference and binocular vision. Based on the high-precision ranging information obtained by frequency scanning interference technology, multi-position ranging network forward intersection technology is adopted, and an automatic target search algorithm is added to realize batch high-precision coordinate information collection of multiple points in space.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a micron-level high-precision automatic three-dimensional positioning device based on frequency interferometry and binocular vision, comprising two or more hosts, each of which comprises:

[0007] A horizontal and tilt turntable having a horizontal rotation axis and a tilt rotation axis;

[0008] The distance measurement module is fixedly mounted on the rotating mechanism of the horizontal and pitch turntable, and is used to transmit frequency-modulated laser light to the target sphere and receive the reflected signal, and obtain the absolute distance value to the target sphere by solving the interference fringes;

[0009] A binocular vision positioning module is fixedly mounted on the rotation mechanism of the pan and tilt turntable and includes two calibrated image sensors for identifying the pixel position of the target sphere and outputting the pan and tilt angles to the pan and tilt turntable;

[0010] The multi-station network control system is used to calculate the horizontal angle and pitch angle of the point relative to the current ranging module based on the binocular vision positioning information obtained by the binocular vision positioning module, and transmit the angle information to the horizontal and pitch turntables to guide the ranging module to aim at the corresponding target ball, realizing automatic target search and aiming functions;

[0011] The two or more hosts work together in the following ways:

[0012] The binocular vision positioning module of each host synchronously observes the common target ball and calculates the relative orientation parameters between the hosts;

[0013] The frequency scanning interferometric ranging module of each host is driven by the turntable to aim at the same target ball to obtain high-precision ranging data;

[0014] Based on the relative orientation parameters and multi-station ranging data, the three-dimensional spatial coordinates of the target sphere are calculated using a forward intersection adjustment algorithm.

[0015] As a preferred technical solution, the distance measurement module includes a tunable injection laser, a dual beam splitter and a sensor; the tunable laser outputs wavelength-adjustable laser light, which is divided into a measurement light path and a reference light path by the beam splitter;

[0016] The measuring light path illuminates the target sphere through the circulator and collimator. After the reflected signal returns, it forms interference fringes with the reference light path at the optical sensor. The optical sensor calculates the absolute distance value by solving the phase change of the interference fringes. The formula is:

[0017]

[0018] Where Δ is the laser sweep rate and F is the interference fringe frequency.

[0019] As an optimal technical solution, the binocular vision positioning module includes two image sensors, which are calibrated to obtain the relative position relationship and the orientation elements in each camera, obtain the position of the target ball in the current field of view and the approximate value of the global reference coordinates, inversely calculate the relative horizontal angle and vertical angle relative to the binocular vision positioning module, and transmit them to the turntable drive ranging module to aim at the target ball.

[0020] As an optimal technical solution, the target ball is used to reflect the laser beam of the ranging module; the target ball is a homogeneous glass ball, and the interior is made of glass microbeads to make an embedded spherical layer to achieve high-contrast reflection under the binocular vision positioning field of view to facilitate determination of the pixel position of the target ball.

[0021] As an optimal technical solution, in the multi-station network control system, the initial parameter values ​​are calculated through the binocular vision positioning module in combination with known points in space to obtain the coordinates and posture of each ranging module in the current reference coordinate system, and then combined with the vertical angle, horizontal angle and distance of the target ball to obtain the approximate coordinates of the target point in the reference coordinate system.

[0022] As a preferred technical solution, the horizontal rotation range of the horizontal and pitch turntables is 360°, and the pitch rotation range is not less than 270°.

[0023] In a second aspect, the present invention provides a positioning method for a micron-level high-precision automatic three-dimensional positioning device based on frequency interferometry and binocular vision, comprising the following steps:

[0024] S1. The injected tunable laser is split into a measurement beam and a local oscillator beam after passing through a beam splitter. The local oscillator beam enters the detector through a delayed optical fiber with a fixed optical path. The measurement beam passes through a circulator and a collimator to illuminate the target. The return signal re-enters the collimator and circulator to reach the detector and merges with the local oscillator beam to produce interference. The absolute distance measurement value is calculated based on the tunable laser center frequency, linewidth, light speed, optical path, interference fringe phase, and instantaneous frequency.

[0025] S2. Acquire the image of the measurement area in the current field of view, and obtain the image information of the target ball with high reflective brightness by adjusting the contrast and brightness information. Based on the binocular vision positioning information obtained by the binocular vision positioning module, calculate the horizontal angle and pitch angle of the point relative to the current ranging module, and transmit the angle information to the horizontal and pitch turntables to guide the ranging module to aim at the corresponding target ball, thereby realizing the automatic target search and aiming function;

[0026] S3. After obtaining the absolute distance information from the spatial multi-points to each measurement module, the coordinates of the spatial multi-points in the current reference system are calculated through forward intersection adjustment.

[0027] As a preferred technical solution, in step S1, the absolute distance information is calculated as follows:

[0028] The interference fringe phase φ(t) and instantaneous frequency f(t) are obtained by phase differentiation as follows:

[0029] φ(t)=2πL(t)v(t) / c;

[0030]

[0031] Where v(t) is the laser center frequency, w is the line width, c is the speed of light, and L(t) is the optical path length.

[0032] The optical path difference is twice the actual measured distance x.

[0033]

[0034] Assume that the fixed sweep rate is Δv(t) = v0 + Δ·t and substitute it into the instantaneous frequency calculation formula to obtain the absolute distance information x:

[0035]

[0036] As a preferred technical solution, step S2 is specifically as follows:

[0037] In a binocular vision system, the depth of an object is determined by calculating the disparity of homologous points in two camera images. The disparity d is calculated using the following formula:

[0038]

[0039] Where f is the focal length of the camera, X c and Z c are the coordinates in the camera coordinate system;

[0040]

[0041] The pixel position deviation of the same scene imaged by two cameras is called disparity. Through binocular correction, the depth estimation is converted into feature point matching and disparity calculation. The relationship between disparity d and depth Z is:

[0042]

[0043] Therefore, the image of the target scene is captured through the binocular camera, and its internal and external parameters are given in combination with camera calibration. The distortion is eliminated by combining stereo correction to complete the matching. Finally, the binocular vision system can extract the position and direction information of the object in three-dimensional space from the images of the two cameras.

[0044] As a preferred technical solution, step S3 is specifically as follows:

[0045] Using the high-precision ranging observations obtained between the instrument and the target sphere, and combining them with redundant observations from multiple instruments and multiple stations, a rigorous overall least squares adjustment is performed to obtain the three-dimensional spatial coordinates of the target sphere with high precision and high reliability. The specific process is as follows:

[0046] The distance from a point i in space to the measurement center q0 of the ranging module

[0047]

[0048] Among them, x i ,y i ,z i is the global three-dimensional coordinate of a point i in space, The global three-dimensional coordinates of the measurement center q0 of the ranging module;

[0049] Construct the observation equation:

[0050]

[0051] in, is the absolute distance measurement observation value from a point i in space to the measurement center q0 of the ranging module;

[0052] Nonlinear equations need to be linearized and then solved by least squares parameters:

[0053]

[0054] X=[δx i ,δy i ,δz i ] T ;

[0055]

[0056] Where V is the absolute range observation residual, is the approximate global three-dimensional coordinate of a point i in space, δx i ,δy i ,δz i is the correction number of the approximate global three-dimensional coordinate of a point i in space, is the least squares adjustment constant term of the current observation equation, and P is the observation weight matrix;

[0057] The weight matrix P is determined according to the distance from the point to the module:

[0058]

[0059] The initial value of the parameters is calculated by binocular vision positioning, combined with the known points in space to obtain the coordinates and posture of each ranging module in the current reference coordinate system, and then combined with the vertical angle of the sighting target reflector ball. Horizontal angle θ and distance Get the approximate coordinates of the target point in the reference coordinates.

[0060] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0061] The present invention provides a micron-level high-precision automatic three-dimensional positioning device and positioning method based on frequency interferometry and binocular vision. Compared with traditional interferometric ranging methods, it has significant advantages and effects:

[0062] Improved efficiency: Abandoning the limitations of manually guided measurement, the work efficiency of the measurement process is greatly improved through automated target recognition and aiming technology. The advantages are particularly obvious in scenarios where frequent and repeated measurements are required.

[0063] Improved accuracy: High-contrast image processing technology is used to highlight the target sphere, and binocular vision positioning information is combined to accurately calculate the target's attitude angle relative to the ranging module, ensuring alignment accuracy and thus improving overall measurement accuracy.

[0064] Simplified operation: An integrated process from image acquisition and target recognition to angle calculation and automatic aiming is realized, which reduces human intervention and simplifies the operation steps, allowing non-professionals to easily complete complex measurement tasks.

[0065] Strong adaptability: This method can adapt to measurement needs in different environments. Through real-time processing of images in the field of view, it can stably and reliably identify and aim at the target even when lighting conditions change.

[0066] High degree of automation: The entire system is designed with automation as its core. It not only realizes the automatic target search and aiming functions, but also can transmit the calculated angle information to the turntable to achieve precise control of the ranging module, greatly improving the automation level of the measurement work.

[0067] In summary, the present invention provides an efficient, accurate and easy-to-operate multi-point distance measurement solution, which is suitable for various applications requiring fast and precise distance measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0069] Figure 1 This is a schematic structural diagram of a micron-level high-precision automatic three-dimensional positioning device based on frequency interferometry and binocular vision according to an embodiment of the present invention;

[0070] Figure 2 For the embodiment of the present invention Figure 1 Schematic diagram of the structure of a single host;

[0071] Figure 3 Schematic diagram of binocular vision positioning according to an embodiment of the present invention;

[0072] Figure 4 Schematic diagram of a target ball according to an embodiment of the present invention;

[0073] Figure 5 It is a flowchart of a positioning method according to an embodiment of the present invention.

[0074] Explanation of the accompanying figures: 1. Horizontal and vertical turntable; 2. Distance measurement module; 3. Binocular vision positioning module; 4. Target ball; 401. Homogeneous glass ball; 402. Embedded spherical layer. DETAILED DESCRIPTION

[0075] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0076] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0077] like Figure 1 、 Figure 2 As shown, this embodiment provides a micron-level high-precision automatic three-dimensional positioning device based on frequency interferometry and binocular vision, including two or more hosts, each host having a horizontal and pitch turntable 1, a ranging module 2, a binocular vision positioning module 3, and a multi-station networking control system; the present invention uses the high-precision ranging information obtained by the ranging module based on frequency scanning interferometry technology, adopts the multi-position ranging networking forward intersection technology, and adds an automatic target search method to realize batch high-precision coordinate information collection of multiple points in space.

[0078] Furthermore, the horizontal and tilt turntable 1 has a horizontal rotation axis and a tilt rotation axis; its horizontal rotation range is 360°, and its tilt rotation range is not less than 270°.

[0079] In a specific example, the horizontal and pitch turntable includes a base and a bracket, the bracket is arranged on the base, a turntable is provided between the base and the bracket, and the bracket can rotate 360° in the horizontal range with the turntable; the bracket is provided with a ranging module 2 and a binocular vision positioning module 3, which are arranged on the bracket in a hinged manner through a carrier, thereby achieving a rotation of not less than 270° in the vertical range.

[0080] Furthermore, the distance measuring module 2 is fixedly mounted on the rotating mechanism of the horizontal and pitch turntable 1, and is used to emit frequency-modulated laser to the target sphere 4 and receive the reflected signal, and obtain the absolute distance value to the target sphere by solving the interference fringes.

[0081] Furthermore, the distance measurement module 2 includes a tunable injection laser, a dual beam splitter and a sensor; after the measurement light path and the reference light path are transmitted, interference is formed in the sensor and the absolute distance measurement information between the module and the target ball 4 is obtained by calculation, such as Figure 3 As shown, the details are as follows:

[0082] The tunable laser outputs wavelength-tunable laser light, which is divided into a measurement light path and a reference light path by an optical splitter;

[0083] The measuring light path illuminates the target sphere 4 through the circulator and collimator. After the reflected signal returns, it forms interference fringes with the reference light path at the optical sensor. The optical sensor calculates the absolute distance value by solving the phase change of the interference fringes. The formula is:

[0084]

[0085] Where Δ is the laser sweep rate and F is the interference fringe frequency.

[0086] Furthermore, the binocular vision positioning module 3 includes two image sensors, which are calibrated to obtain the relative position relationship and the orientation elements in each camera, obtain the position of the target ball in the current field of view and the approximate value of the global reference coordinates, inversely calculate the relative horizontal angle and vertical angle relative to the binocular vision positioning module, and pass them to the turntable drive ranging module to aim at the target ball.

[0087] Further, such as Figure 4As shown in parts (a) and (b), the target ball 4 is characterized by a homogeneous glass ball 401, which can reflect the laser beam of the frequency scanning interferometer ranging module 1 with high intensity; the embedded spherical layer 402 made of glass microbeads inside realizes high-contrast reflection under the binocular vision positioning field, which facilitates the determination of the pixel position of the target ball.

[0088] Glass microbeads are widely used as a raw material in industrial manufacturing. These spheres, ranging in size from a few microns to tens of microns, possess excellent reflective properties, capable of reflecting parallel light along its original path. Currently, all types of reflective products are made with glass microbeads as a coating. By coating the spheres with glass microbeads, they can reflect parallel incident light along its original direction, achieving high reflectivity for interfering lasers and brightness differences for binocular visual target search.

[0089] Furthermore, the multi-station networking control system is used to calculate the horizontal angle and pitch angle of the point relative to the current ranging module based on the binocular vision positioning information obtained by the binocular vision positioning module, and transmit the angle information to the horizontal and pitch turntables to guide the ranging module to aim at the corresponding target ball, thereby realizing automatic target search and aiming functions.

[0090] The method comprises the following steps: a multi-point forward intersection measurement network is constructed by an integrated ranging and positioning module formed by a plurality of frequency scanning interferometer ranging modules 2, a binocular vision positioning module 3, and a horizontal and pitch turntable 1; after batch-automatically obtaining the absolute ranging information of multi-point target balls relative to each integrated module and their approximate coordinates in a reference coordinate system, an adjustment calculation is performed based on a least squares adjustment criterion and relative distance weighting to obtain the adjusted coordinates of the multi-points in the reference coordinate system, thereby completing multi-point three-dimensional high-precision and high-efficiency acquisition.

[0091] It can be understood that in the multi-station network control system, the initial parameter values ​​are calculated through the binocular vision positioning module in combination with the known points in space to obtain the coordinates and posture of each ranging module in the current reference coordinate system, and then combined with the vertical angle, horizontal angle and distance of the target ball to obtain the approximate coordinates of the target point in the reference coordinate system.

[0092] like Figure 5 As shown, in another embodiment of the present application, a positioning method for a micron-level high-precision automatic three-dimensional positioning device based on frequency interferometry and binocular vision is provided, which specifically includes the following steps:

[0093] Step S1: The injected tunable laser is divided into a measurement beam and a local oscillator beam after passing through a beam splitter. The local oscillator beam enters a detector through a delayed optical fiber with a fixed optical path. The measurement beam passes through a circulator and a collimator to illuminate the target. The return signal re-enters the collimator and circulator to reach the detector and merges with the local oscillator beam to generate interference. Absolute ranging information is calculated based on the tunable laser center frequency, linewidth, light speed, optical path, interference fringe phase, and instantaneous frequency.

[0094] Furthermore, the absolute distance information is calculated as follows:

[0095] The interference fringe phase φ(t) and instantaneous frequency f(t) are obtained by phase differentiation as follows:

[0096] φ(t)=2πL(t)v(t) / c;

[0097]

[0098] Where v(t) is the laser center frequency, w is the line width, c is the speed of light, and L(t) is the optical path length.

[0099] The optical path difference is twice the actual measured distance x.

[0100]

[0101] Assume that the fixed sweep rate is Δv(t) = v0 + Δ·t and substitute it into the instantaneous frequency calculation formula to obtain the absolute distance information x:

[0102]

[0103] In practical applications, based on this principle and combined with the influence of factors such as the actual laser measurement environment, it is necessary to adopt a specific method of adding a reference optical path to eliminate the nonlinear error of light source tuning.

[0104] Step S2: Automatically search for a target and aim at it;

[0105] In the actual measurement process of multi-point ranging, the efficiency of traditional interferometric ranging methods is mainly affected by manual guidance. Automatic target search can greatly improve efficiency and is more efficient during repeated measurements. The image of the measurement area in the current field of view is acquired. By adjusting the contrast and brightness information, the image information of the target sphere with high reflective brightness is obtained. Based on the binocular vision positioning information obtained by the binocular vision positioning module, the horizontal angle and pitch angle of the point relative to the current ranging module are calculated. This angle information is transmitted to the horizontal and pitch turntables, guiding the ranging module to aim at the corresponding target sphere, realizing automatic target search and aiming functions.

[0106] Furthermore, step S2 is specifically as follows:

[0107] In a binocular vision system, the depth of an object is determined by calculating the disparity of homologous points in two camera images. The disparity d is calculated using the following formula:

[0108]

[0109] Where f is the focal length of the camera, X c and Z c are the coordinates in the camera coordinate system;

[0110]

[0111] The pixel position deviation of the same scene imaged by two cameras is called disparity. Through binocular correction, the depth estimation is converted into feature point matching and disparity calculation. The relationship between disparity d and depth Z is:

[0112]

[0113] Therefore, the image of the target scene is captured through the binocular camera, and its internal and external parameters are given in combination with camera calibration. The distortion is eliminated by combining stereo correction to complete the matching. Finally, the binocular vision system can extract the position and direction information of the object in three-dimensional space from the images of the two cameras.

[0114] With the above steps and formulas, the binocular vision system can extract the position and direction information of the object in three-dimensional space from the images of two cameras.

[0115] S3, after obtaining the absolute distance information of the spatial multi-point to each measurement module, the coordinates of the spatial multi-point in the current reference system are calculated by forward intersection adjustment; specifically:

[0116] Using the high-precision ranging observations obtained between the instrument and the target sphere, and combining them with redundant observations from multiple instruments and multiple stations, a rigorous overall least squares adjustment is performed to obtain the three-dimensional spatial coordinates of the target sphere with high accuracy and reliability. The specific process is as follows:

[0117] The distance from a point i in space to the measurement center q0 of the ranging module

[0118]

[0119] Among them, x i ,y i ,z i is the global three-dimensional coordinate of a point i in space, The global three-dimensional coordinates of the measurement center q0 of the ranging module;

[0120] Construct the observation equation:

[0121]

[0122] in, is the absolute distance measurement observation value from a point i in space to the measurement center q0 of the ranging module;

[0123] Nonlinear equations need to be linearized and then solved by least squares parameters:

[0124]

[0125] X=[δx i ,δy i ,δz i ] T ;

[0126]

[0127]

[0128] Where V is the absolute range observation residual, is the approximate global three-dimensional coordinate of a point i in space, δx i ,δy i ,δz i is the correction number of the approximate global three-dimensional coordinate of a point i in space, is the least squares adjustment constant term of the current observation equation, and P is the observation weight matrix;

[0129] The weight matrix P is determined according to the distance from the point to the module:

[0130]

[0131] The initial value of the parameters is calculated by binocular vision positioning, combined with the known points in space to obtain the coordinates and posture of each ranging module in the current reference coordinate system, and then combined with the vertical angle of the sighting target reflector ball. Horizontal angle θ and distance Get the approximate coordinates of the target point in the reference coordinates.

[0132] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision, characterized by: Includes two or more hosts, each of which includes: A horizontal and tilt turntable having a horizontal rotation axis and a tilt rotation axis; A distance measurement module is fixedly mounted on the rotating mechanism of the pan and tilt turntable, and is used to emit a frequency-modulated laser toward the target sphere and receive the reflected signal, thereby obtaining the absolute distance to the target sphere by calculating the interference fringes. The distance measurement module includes a tunable injection laser, a dual beam splitter, and a sensor. The tunable injection laser outputs a wavelength-adjustable laser, which is divided into a measurement optical path and a reference optical path by the beam splitter. The measuring light path illuminates the target sphere through the circulator and collimator. After the reflected signal returns, it forms interference fringes with the reference light path at the optical sensor. The optical sensor calculates the absolute distance value by solving the phase change of the interference fringes. The formula is: Where Δ is the laser sweep rate, F is the interference fringe frequency, and c is the speed of light; A binocular vision positioning module is fixedly mounted on the rotation mechanism of the pan and tilt turntable and includes two calibrated image sensors for identifying the pixel position of the target sphere and outputting the pan and tilt angles to the pan and tilt turntable; The multi-station network control system is used to calculate the horizontal angle and pitch angle of the point relative to the current ranging module based on the binocular vision positioning information obtained by the binocular vision positioning module, and transmit the angle information to the horizontal and pitch turntables to guide the ranging module to aim at the corresponding target ball, realizing automatic target search and aiming functions; The two or more hosts work together in the following ways: The binocular vision positioning module of each host synchronously observes the common target ball and calculates the relative orientation parameters between the hosts; The frequency scanning interferometric ranging module of each host is driven by the turntable to aim at the same target ball to obtain high-precision ranging data; Based on the relative orientation parameters and multi-station ranging data, the three-dimensional spatial coordinates of the target sphere are calculated using a forward intersection adjustment algorithm.

2. The micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision according to claim 1 is characterized in that: The binocular vision positioning module includes two image sensors. After calibration, the relative position relationship and the orientation elements in each camera are obtained, the position of the target ball in the current field of view and the approximate value of the global reference coordinates are obtained, the relative horizontal angle and vertical angle relative to the binocular vision positioning module are inversely calculated, and the results are transmitted to the turntable drive ranging module to aim at the target ball.

3. The micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision according to claim 1 is characterized in that: The target ball is used to reflect the laser beam of the ranging module; the target ball is a homogeneous glass ball, and the interior is made of glass microbeads to make an embedded spherical layer to achieve high-contrast reflection under the binocular vision positioning field, which facilitates the determination of the pixel position of the target ball.

4. The micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision according to claim 1 is characterized in that: In the multi-station network control system, the initial parameter values ​​are calculated by the binocular vision positioning module in combination with known points in space to obtain the coordinates and posture of each ranging module in the current reference coordinate system. Then, the vertical angle, horizontal angle and distance of the sighting target sphere are combined to obtain the approximate coordinates of the target point in the reference coordinate system.

5. The micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision according to claim 1 is characterized in that: The horizontal rotation range of the horizontal and pitch turntables is 360°, and the pitch rotation range is not less than 270°.

6. The positioning method of the micron-level high-precision automatic three-dimensional positioning device based on frequency interference and binocular vision according to any one of claims 1 to 5, characterized in that: The steps include: S1. The injected tunable laser is split into a measurement beam and a local oscillator beam after passing through a beam splitter. The local oscillator beam enters the detector through a delayed optical fiber with a fixed optical path. The measurement beam passes through a circulator and a collimator to illuminate the target. The return signal re-enters the collimator and circulator to reach the detector and merges with the local oscillator beam to produce interference. The absolute distance measurement value is calculated based on the tunable laser center frequency, light speed, optical path, interference fringe phase, and instantaneous frequency. S2. Acquire the image of the measurement area in the current field of view, and obtain the image information of the target ball with high reflective brightness by adjusting the contrast and brightness information. Based on the binocular vision positioning information obtained by the binocular vision positioning module, calculate the horizontal angle and pitch angle of the point relative to the current ranging module, and transmit the angle information to the horizontal and pitch turntables to guide the ranging module to aim at the corresponding target ball, thereby realizing the automatic target search and aiming function; S3. After obtaining the absolute distance information from the spatial multi-points to each measurement module, the coordinates of the spatial multi-points in the current reference system are calculated through forward intersection adjustment.

7. The positioning method according to claim 6, characterized in that: In step S1, the absolute distance information is calculated as follows: The interference fringe phase φ(t) and instantaneous frequency f(t) are obtained by phase differentiation as follows: φ(t)=2πL(t)v(t) / c; Where v(t) is the center frequency of the laser, c is the speed of light, and L(t) is the optical path. The optical path difference is twice the actual measured distance x. Assume that the fixed sweep rate is Δv(t) = v0 + Δ·t and substitute it into the instantaneous frequency calculation formula to obtain the absolute distance information x: Where Δ is the laser sweep rate and F is the interference fringe frequency.

8. The positioning method according to claim 6, characterized in that: Step S2 is specifically as follows: In a binocular vision system, the depth of an object is determined by calculating the disparity of homologous points in two camera images. The disparity d is calculated using the following formula: Where f is the focal length of the camera, X c 、Y c and Z c are the coordinates in the camera coordinate system; The pixel position deviation of the same scene imaged by two cameras is called disparity. Through binocular correction, the depth estimation is converted into feature point matching and disparity calculation. The relationship between disparity d and depth Z is: Therefore, the image of the target scene is captured through the binocular camera, and its internal and external parameters are given in combination with camera calibration. The distortion is eliminated by combining stereo correction to complete the matching. Finally, the binocular vision system can extract the position and direction information of the object in three-dimensional space from the images of the two cameras.

Images