Large-scale multi-position-indicator spatial ranging system and method based on visible light

Abstract

The invention discloses a visible light-based large-scale multi-position-indicator spatial ranging system and a visible light-based large-scale multi-position-indicator spatial ranging method. The system comprises three position indicators, three mark bridging objects, a gradienter, a mark probe and a computer, the three position indicators are a first position indicator, a second position indicator and a third position indicator; and the three marked bridging objects are a first single-sided marked bridging object, a second single-sided marked bridging object and a double-sided marked bridging object. The distance measuring method comprises the following steps: step 1, building the distance measuring system; 2, determining the positions of the three position indicators and the positions of the three marked bridging objects; 3, the positioning instrument identifies and distinguishes the marking bridging object and the marking probe; 4, unifying a coordinate system and converting coordinates; and step 5, measuring the distance in the distance measurement range of the system by using the marking probe. According to the invention, the coordinate information of a plurality of groups of position indicators is unified on a specific marked bridging object, and the related coordinate information of the marked bridging object is easier to obtain, so that the distance measurement range is widened, and the test precision is also ensured.

Description

Technical Field

[0001] The present invention relates to the field of space distance measurement technology, and in particular to a large-scale multi-positioner space distance measurement system and method based on visible light. Background Art

[0002] The current spatial distance measurement methods are mainly laser sensor distance measurement and binocular camera visual distance measurement. Laser distance measurement uses the identification and pickup of the emitted light beam, captures the flight time of the laser pulse between two space targets, and calculates the distance between the two targets. It is mainly used for long-distance detection, such as satellite altitude measurement, ground combat system distance measurement, etc. Binocular visual distance measurement uses two cameras to simulate binoculars, analyzes the images of objects detected at different positions, and detects the distance. It involves steps such as image processing, feature extraction, point matching, and posture solution. The algorithm involved is relatively complex, but the accuracy is higher than laser distance measurement when measuring close objects.

[0003] The laser ranging system is complex in layout and has high requirements for the surface of the object. The laser pulse echo intensity will be affected by the scattering characteristics of the atmosphere and the target, resulting in large fluctuations. Real-time monitoring of the laser power to troubleshoot is a relatively important link, but it is costly and not suitable for small and medium distance distance measurement. The current binocular camera visual ranging is affected by the camera's field of view and is mostly suitable for close-range point detection. The general detection range is about 1.5 meters, and the relative error of ranging will be larger as the range increases. Therefore, combining the advantages of binocular camera visual ranging with high accuracy, improving the binocular camera visual ranging method, increasing its test range, and simplifying the test operation are urgent research directions. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem that the present invention intends to solve is to provide a large-scale multi-locator spatial ranging system and method based on visible light.

[0005] The technical solution of the present invention to solve the technical problem of the system is to provide a large-scale multi-locator space distance measurement system based on visible light, characterized in that the system includes three locators, three marking bridges, a level, a marking probe and a computer; the three locators are a first locator, a second locator and a third locator; the three marking bridges are a first single-sided marking bridge, a second single-sided marking bridge and a double-sided marking bridge;

[0006] At least three marks are arranged on the front sides of the first single-sided marking bridge and the second single-sided marking bridge, the distances between any two marks on the same side are different, and no marks are arranged on the back side; at least three marks are arranged on the front and back sides of the double-sided marking bridge, and the distances between any two marks on the same side are different; the mark arrangement on the front side of the double-sided marking bridge is the same as that on the front side of the second single-sided marking bridge, and the mark arrangement on the back side is different from that on the first single-sided marking bridge and the second single-sided marking bridge; at least three marks are arranged on the front side of the end of the marking probe, the distances between any two marks are different, and no marks are arranged on the back side; the marking probe is used to measure the distance within the ranging range of the system;

[0007] The level is installed on the first single-sided marking bridge; the distance measuring software is installed in the computer; the first locator, the second locator and the third locator are connected to the computer for communication; the three locators are placed at intervals, and there are two placement methods:

[0008] The first placement method: the three locators are placed on the same side, from left to right, they are the first locator, the second locator and the third locator, the first locator and the third locator have an inclination angle relative to the vertical plane; the first single-sided marked bridge is located between the first locator and the second locator, and is located within the field of view of the first locator and the second locator; the second single-sided marked bridge is located between the second locator and the third locator, and is located within the field of view of the second locator and the third locator;

[0009] The second placement method: from left to right, they are the first locator, the second locator and the third locator, the first locator and the second locator are placed on the same side, the third locator is placed on the opposite side of the first locator and the second locator, and the third locator is arranged in reverse, and the first locator has an inclination angle relative to the vertical plane; the first single-sided marked bridge is located between the first locator and the second locator, and is located within the field of view of the first locator and the second locator; the double-sided marked bridge is located between the second locator and the third locator, and the front side of the double-sided marked bridge is located within the field of view of the second locator, and the back side is located within the field of view of the third locator.

[0010] The technical solution of the present invention to solve the technical problem of the method is to provide a large-scale multi-positioner spatial ranging method based on visible light, characterized in that the method comprises the following steps:

[0011] Step 1, building the distance measurement system;

[0012] Step 2: Determine the positions of the three locators and the three marked bridges:

[0013] For the first placement method, the display image of the first single-sided marked bridge object by the first locator is moved to the rightmost end of the field of view, ensuring that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge object and the second single-sided marked bridge object are respectively placed at the leftmost end and the rightmost end of the field of view of the second locator, thereby fixing the positions of the first single-sided marked bridge object and the second single-sided marked bridge object; the display image of the second single-sided marked bridge object by the third locator is moved to the leftmost end of the field of view, ensuring that the field of view from the rightmost end is included in the distance measurement range of the system;

[0014] For the second placement method, the display image of the first single-sided marked bridge object by the first locator is moved to the rightmost end of the field of view, ensuring that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge object and the double-sided marked bridge object are placed at the leftmost end and the rightmost end of the field of view of the second locator respectively, thereby fixing the positions of the first single-sided marked bridge object and the double-sided marked bridge object; the display image of the double-sided marked bridge object by the third locator is moved to the leftmost end of the field of view, ensuring that the field of view from the rightmost end is included in the distance measurement range of the system;

[0015] Step 3, the locator identifies and distinguishes the marker bridge and the marker probe: After the arrangement is completed, two marker bridges appear in the field of view of the second locator in each arrangement mode, and the instrument fusion algorithm is used to realize the identification of each marker bridge and marker probe and the distinction between different marker bridges and marker probes;

[0016] Step 4: Unify the coordinate system and transform the coordinates:

[0017] For the first placement method, the first locator and the third locator are respectively moved to the position of the second locator, and double bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object and the second single-sided marked bridge object, and then the first locator and the third locator are moved to the corresponding positions of the respective placement methods in the steps;

[0018] For the second placement method, the first locator and the third locator are respectively moved to the position of the second locator, and double-bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object and the double-sided marked bridge object; then the first locator and the third locator are moved to the corresponding positions of their respective placement methods in step 2, and the third locator is subjected to triple-bridging operations to establish a coordinate conversion matrix for the third locator from the back side of the double-sided marked bridge object to the front side and then to the first single-sided marked bridge object;

[0019] Step 5. Use the marking probe to measure the distance within the system's ranging range: the marking probe enters the field of view of any locator, and the locator recognizes the end mark of the marking probe; then the tip of the marking probe is placed at the two positions where the distance needs to be measured, and geometric calculations are performed to complete the ranging.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention uses multiple groups of locators, combines the advantages of high accuracy of binocular camera visual ranging, and proposes a reasonable and effective coordination scheme for multiple groups of locators. More combinations can be made for the use of locators. Compared with the traditional locator ranging system, the ranging range is broadened. Compared with the laser ranging system, the environmental requirements for system layout are greatly reduced. By adjusting the camera exposure, it can be applied to test scenes in different light intensity environments.

[0022] (2) The distance measurement system of the present invention only needs to move the marking probe to take points for distance measurement during the distance measurement operation, without moving the locator system and the marking bridge. The positions of the locator system and the marking bridge can be adjusted and then fixed according to the distance measurement needs. The customized positioning method and relatively fixed position system are more convenient for tooling in various test scenarios.

[0023] (3) The present invention proposes a new coordinate conversion method, which unifies the coordinate information of multiple groups of locators on a specific marking bridge object. The relevant coordinate information of the marking bridge object is easier to obtain. While widening the distance measurement range, the test accuracy is also guaranteed. Moreover, the marking bridge object can be rigidly installed on the measured object or fixture, avoiding the situation where the locator is accidentally hit and causes inaccurate measurement.

[0024] (4) The software platform of the present invention is developed as a whole. In the interface function, image content information and point coordinate information can be directly displayed. At the same time, the three-dimensional information of the test object can be imported to perform point prompt operations. After the marked bridge object is recognized in the image, the measurement operation can be started. After the measurement is completed, the measurement results can be recorded and stored in real time.

[0025] (5) The algorithm of the present invention is developed using C++ language, in which a threshold comparator is used to constrain the accuracy, and points that do not meet the registration accuracy and attitude solution are eliminated and re-collected. The overall development uses QT for interface development, and the slot function instructions in QT are used to realize the connection and communication with the selected commands in the ranging process.

[0026] (6) The present invention uses three marking plates and one marking probe, and designs a double-sided marking bridge to meet the needs of placing the locator in different positions. The marking probe is used as a marking device for selecting distance coordinates.

[0027] (7) The present invention adopts two placement methods according to different depth measurement ranges. The first placement method is simple to operate and accurate. The second placement method relatively widens the longitudinal measurement range. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of a first arrangement of multiple locators of the present invention; in the figure, the area included in the dotted line drawn from each locator is the measurement range of the locator;

[0029] Figure 2 Schematic diagram of the second arrangement of the multiple locators of the present invention; in the figure, the area included in the dotted line drawn by each locator is the measurement range of the locator;

[0030] Figure 3 It is a schematic diagram of the three-dimensional structure of the first single-sided marking bridge of the present invention;

[0031] Figure 4 It is a schematic diagram of the three-dimensional structure of the second single-sided marking bridge of the present invention;

[0032] Figure 5 It is a schematic diagram of the three-dimensional structure of the double-sided marking bridge of the present invention;

[0033] Figure 6 It is a front view schematic diagram of the double-sided marking bridge of the present invention;

[0034] Figure 7 It is a schematic diagram of the reverse side of the double-sided marking bridge of the present invention;

[0035] Figure 8 is a schematic diagram of the three-dimensional structure of the labeling probe of the present invention;

[0036] Fig. 9 This is an interface diagram of the distance measurement software developed based on QT of the present invention.

[0037] In the figure, there are a first locator 1 , a second locator 2 , a third locator 3 , a first single-sided marking bridge 4 , a second single-sided marking bridge 5 , a double-sided marking bridge 6 , a level 7 , and a marking probe 8 . DETAILED DESCRIPTION

[0038] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the present invention.

[0039] The present invention also provides a large-scale multi-positioner space distance measurement system based on visible light (referred to as system), characterized in that the system includes three positioners, three marking bridges, a level 7, a marking probe 8 and a computer; the three positioners are a first positioner 1, a second positioner 2 and a third positioner 3; the three marking bridges are a first single-sided marking bridge 4, a second single-sided marking bridge 5 and a double-sided marking bridge 6;

[0040] At least three marks are arranged on the front side of the first single-sided marking bridge 4 and the second single-sided marking bridge 5, the distances between any two marks on the same side are different, and no marks are arranged on the back side; at least three marks are arranged on the front and back sides of the double-sided marking bridge 6, and the distances between any two marks on the same side are different; the mark arrangement on the front side of the double-sided marking bridge 6 is the same as that on the front side of the second single-sided marking bridge 5, and the mark arrangement on the back side is different from that on the first single-sided marking bridge 4 and the second single-sided marking bridge 5; at least three marks are arranged on the front side of the end of the marking probe 8, the distances between any two marks are different, and no marks are arranged on the back side; the marking probe 8 is used to measure the distance within the ranging range of the system;

[0041] The level 7 is installed on the first single-sided marked bridge 4 to ensure that the first single-sided marked bridge 4 is placed vertically with the ground and the measurement accuracy of the projection distance is ensured; the distance measurement software is installed in the computer; the first locator 1, the second locator 2 and the third locator 3 are connected to the computer through USB communication to transmit data and realize control; the three locators are placed at intervals, and are divided into two placement methods according to the different depth measurement ranges:

[0042] The first placement method: the three locators are placed on the same side, from left to right, they are the first locator 1, the second locator 2 and the third locator 3, the first locator 1 and the third locator 3 have an inclination angle relative to the vertical plane; the first single-sided marked bridge 4 is located between the first locator 1 and the second locator 2, and is located within the field of view of the first locator 1 and the second locator 2; the second single-sided marked bridge 5 is located between the second locator 2 and the third locator 3, and is located within the field of view of the second locator 2 and the third locator 3;

[0043] The second arrangement method: from left to right, they are the first locator 1, the second locator 2 and the third locator 3, the first locator 1 and the second locator 2 are placed on the same side, the third locator 3 is placed on the opposite side of the first locator 1 and the second locator 2, and the third locator 3 is arranged in reverse, the first locator 1 has an inclination angle relative to the vertical plane; the first single-sided marked bridge 4 is located between the first locator 1 and the second locator 2, and is located within the field of view of the first locator 1 and the second locator 2; the double-sided marked bridge 6 is located between the second locator 2 and the third locator 3, and the front side of the double-sided marked bridge 6 is located within the field of view of the second locator 2, and the back side is located within the field of view of the third locator 3.

[0044] The present invention also provides a large-scale multi-locator spatial distance measurement method based on visible light (hereinafter referred to as method), characterized in that the method comprises the following steps:

[0045] Step 1: Build a ranging system;

[0046] The distance measuring system includes three locators, three marking bridges, a level 7, a marking probe 8 and a computer; the three locators are a first locator 1, a second locator 2 and a third locator 3; the three marking bridges are a first single-sided marking bridge 4, a second single-sided marking bridge 5 and a double-sided marking bridge 6;

[0047] At least three marks are arranged on the front side of the first single-sided marking bridge 4 and the second single-sided marking bridge 5, the distances between any two marks on the same side are different, and no marks are arranged on the back side; at least three marks are arranged on the front and back sides of the double-sided marking bridge 6, and the distances between any two marks on the same side are different; the mark arrangement on the front side of the double-sided marking bridge 6 is the same as that on the front side of the second single-sided marking bridge 5, and the mark arrangement on the back side is different from that on the first single-sided marking bridge 4 and the second single-sided marking bridge 5; at least three marks are arranged on the front side of the end of the marking probe 8, the distances between any two marks are different, and no marks are arranged on the back side; the marking probe 8 is used to measure the distance within the ranging range of the system;

[0048] The level 7 is installed on the first single-sided marked bridge 4 to ensure that the first single-sided marked bridge 4 is placed vertically with the ground and the measurement accuracy of the projection distance is ensured; the distance measurement software is installed in the computer; the first locator 1, the second locator 2 and the third locator 3 are connected to the computer through USB communication to transmit data and realize control; the three locators are placed at intervals, and are divided into two placement methods according to the different depth measurement ranges:

[0049] The first placement method: the three locators are placed on the same side, from left to right, they are the first locator 1, the second locator 2 and the third locator 3, the first locator 1 and the third locator 3 have an inclination angle relative to the vertical plane; the first single-sided marked bridge 4 is located between the first locator 1 and the second locator 2, and is located within the field of view of the first locator 1 and the second locator 2; the second single-sided marked bridge 5 is located between the second locator 2 and the third locator 3, and is located within the field of view of the second locator 2 and the third locator 3;

[0050] The second arrangement method: from left to right, there are the first locator 1, the second locator 2 and the third locator 3, the first locator 1 and the second locator 2 are placed on the same side, the third locator 3 is placed on the opposite side of the first locator 1 and the second locator 2, and the third locator 3 is arranged in reverse, the first locator 1 has an inclined angle relative to the vertical plane; the first single-sided marked bridge 4 is located between the first locator 1 and the second locator 2, and is located within the field of view of the first locator 1 and the second locator 2; the double-sided marked bridge 6 is located between the second locator 2 and the third locator 3, and the front side of the double-sided marked bridge 6 is located within the field of view of the second locator 2, and the back side is located within the field of view of the third locator 3;

[0051] Preferably, in step 1, the first locator 1, the second locator 2 and the third locator 3 all adopt binocular camera optical locators.

[0052] Preferably, in step 1, the mark is in a closed shape, preferably a black circular mark (with a diameter of at least 5 mm); the color of the mark and the color of the three mark bridge bodies are selected based on the strongest contrast and the largest color difference.

[0053] Preferably, in step 1, the three locators are all mounted on a tripod and adjusted to a suitable height; the locators are appropriately tilted downward to ensure that the three marked bridges are completely within the field of view of the locators.

[0054] Preferably, in step 1, in the first placement mode, the inclination angle of the first locator 1 and the third locator 3 relative to the vertical plane is 0 to 45°; in the second placement mode, the inclination angle of the first locator 1 relative to the vertical plane is 0 to 45°.

[0055] Preferably, in step 1, the interface of the ranging software includes an area for displaying the left and right fields of view of the camera, three marking bridges and a marking probe 8 identification prompt key, a switch key for switching the camera, operation keys required during the ranging process, and basic keys for saving data, creating a new interface, refreshing the table, and exporting the table.

[0056] Preferably, in step 1, the distance measurement software is a distance measurement software developed based on QT. Fig. 9In the figure, the prompt keys of the bridge and the handheld device on the left will flash to prompt that the marked bridge object and the marked probe 8 have been successfully identified. The "Initialize" button goes to the initial interface, the "Start" button randomly turns on a locator, and the three "Locator" buttons are used to switch locators. The "Start Bridging" button performs a double-bridging operation. The left button of "Start Bridging" performs a triple-bridging operation, and provides "Exposure" and "Gain" progress bars for clicking to adjust parameters. The middle black area is the camera field of view display area, and the "Capture Start Point", "Capture End Point", and "Calculate Distance" buttons on the upper right are used for distance measurement operations, and the table below is used for data recording; the four icon buttons at the top are four basic operations: save data, create a new interface, refresh the table, and export the table.

[0057] Step 2: Determine the positions of the three locators and the three marked bridges:

[0058] For the first placement method, the display image of the first single-sided marked bridge object 4 of the first locator 1 is moved to the rightmost end of the field of view, ensuring that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge object 4 and the second single-sided marked bridge object 5 are respectively placed at the leftmost end and the rightmost end of the field of view of the second locator 2, thereby fixing the positions of the first single-sided marked bridge object 4 and the second single-sided marked bridge object 5; the display image of the second single-sided marked bridge object 5 of the third locator 3 is moved to the leftmost end of the field of view, ensuring that the field of view from the rightmost end is included in the distance measurement range of the system;

[0059] For the second placement method, the display image of the first single-sided marked bridge object 4 of the first locator 1 is moved to the rightmost end of the field of view to ensure that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge object 4 and the double-sided marked bridge object 6 are placed at the leftmost end and the rightmost end of the field of view of the second locator 2 respectively, thereby fixing the positions of the first single-sided marked bridge object 4 and the double-sided marked bridge object 6; the display image of the double-sided marked bridge object 6 of the third locator 3 is moved to the leftmost end of the field of view to ensure that the field of view from the rightmost end is included in the distance measurement range of the system;

[0060] Step 3, the locator identifies and distinguishes the marker bridge and the marker probe 8: After the arrangement is completed, two marker bridges (i.e., the first single-sided marker bridge 4 and the second single-sided marker bridge 5, or the first single-sided marker bridge 4 and the double-sided marker bridge 6) appear in the field of view of the second locator 2 in each arrangement mode, and the instrument fusion algorithm is used to realize the identification of each marker bridge and marker probe 8 and the distinction between different marker bridges and marker probes 8;

[0061] Preferably, in step 3, the specific steps of the instrument fusion algorithm are as follows:

[0062] S31, storing the center coordinates of all the marks of the three marking bridges and the marking probe 8 in the real space in the coordinate system of the second positioning device 2 as element information in the matrix P1; numbering the centers of all the marks on each marking bridge and the marking probe 8 in sequence, and obtaining the center distance between adjacent numbers, and storing this distance value as element information in the matrix P2;

[0063] Using the size information of the maximum closed boundary contour of the marker as a specific threshold, the image feature extraction algorithm is used to extract all closed boundary contours that meet the specific threshold range in the field of view of the second locator 2 to obtain contour points; the contour points include the corresponding contour points of all markers of the first single-sided marker bridge 4, the second single-sided marker bridge 5, the double-sided marker bridge 6 and the marker probe 8 in the field of view, and other redundant contour points generated by clutter that meet the specific threshold range and have closed boundaries; all contour points are then sorted and traversed by the stereo matching algorithm, and the contour points of the left and right cameras of each locator are fitted and judged to complete the one-to-one matching of the left and right contour points; the center coordinates of the matched contour points are then stored as element information in the matrix P3, and the matched contour points are numbered in sequence, and the center distances of adjacent numbers are obtained, and the distance values ​​are stored as element information in the matrix P4; the image feature extraction algorithm and the stereo matching algorithm are used to ensure that the images of the same object in the left and right cameras of the binocular locator appear correctly in their respective fields of view, making preliminary preparations for recognition;

[0064] S32, using the distance information in the matrix P2 as the discrimination threshold, traversing the element information in the matrix P4 in turn, screening out the distance values ​​less than the discrimination threshold, and then determining the corresponding contour points of the marked bridge and the marked probe 8 in the contour points, completing the fusion process of the mark in the real space and the corresponding contour points discriminated by using the distance information, and then reconstructing the mark of each marked bridge and the marked probe 8 in the locator;

[0065] S33. Detect the marking probe 8 and each marking bridge respectively, and record the detection information. Perform PCA dimensionality reduction algorithm or ICP algorithm on the coordinate information of the marker reconstructed by each marking bridge and marking probe 8 and the coordinate information of the marker in the real space to obtain the transformation matrix, realize the registration of corresponding contour points, and then identify and distinguish different marking bridges and marking probes 8.

[0066] Preferably, in step S33, for the marking probe 8, the measuring point is selected by the contact of its tip during measurement, so the tip needs to be calibrated, and the specific steps are as follows:

[0067] S331, ensure that the spatial position of the tip of the marking probe 8 is relatively fixed to the first locator 1, record the coordinate position P5 of the tip in the coordinate system of the first locator 1, and the coordinate position of the tip of the marking probe 8 to the end mark in the coordinate system is P6;

[0068] S332, continuously rotating the marking probe 8, and collecting the coordinate transformation matrix from the coordinate system of the end mark of the marking probe 8 to the coordinate system of the first locator 1 through the rotation calibration data collection process;

[0069] S333. By differentiating and organizing the coordinate transformation matrix, a matrix composed of the coordinate position information in P5 and P6 is obtained to obtain the local coordinate position from the tip of the marker probe 8 to the end marker, so as to realize the recognition of the marker probe 8 by the locator.

[0070] Step 4: Unify the coordinate system and transform the coordinates:

[0071] For the first placement method, the first locator 1 and the third locator 3 are respectively moved to the position of the second locator 2, and double bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object 4 and the second single-sided marked bridge object 5, and stored in the distance measurement software of the computer at the same time, and then the first locator 1 and the third locator 3 are moved to the corresponding positions of their respective placement methods in step 2;

[0072] For the second placement method, the first locator 1 and the third locator 3 are respectively moved to the position of the second locator 2, and double-bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object 4 and the double-sided marked bridge object 6, and stored in the distance measurement software of the computer at the same time; then the first locator 1 and the third locator 3 are moved to the corresponding positions of their respective placement methods in step 2, and the third locator 3 is subjected to triple-bridging operations to establish a coordinate conversion matrix for the third locator 3 from the back side of the double-sided marked bridge object 6 to the front side and then to the first single-sided marked bridge object 4;

[0073] Preferably, after step 4 is completed, each time the system is restarted, the stored file can be directly read in the distance measurement software of the computer to obtain the coordinate transformation matrix information between the marked bridge objects, without repeating the double bridge operation and the triple bridge operation.

[0074] Preferably, in step 4, both the double-bridge operation and the triple-bridge operation adopt an algorithm for posture solution, and the camera and the marked bridge object realize reverse posture solution to achieve the reverse coordinate tracking effect, thereby establishing a posture relationship between the three locators, unifying the point information displayed in the field of view of the first locator 1, the second locator 2 and the third locator 3 to the coordinate system of the first single-sided marked bridge object 4, obtaining the conversion relationship of the point value coordinates between the three locators, and establishing a spatial relationship for large-scale point selection; the specific conversion process of posture solution is as follows:

[0075] S41, the coordinate system of the first single-sided marked bridge 4 is represented as d1, the coordinate systems of the front sides of the second single-sided marked bridge 5 and the double-sided marked bridge 6 are represented as d2, and the coordinate system of the back side of the double-sided marked bridge 6 is represented as d3; the coordinate system of the first locator 1 is represented as m1, the coordinate system of the second locator 2 is represented as m2, and the coordinate system of the third locator 3 is represented as m3;

[0076] S42, the first single-sided marked bridge object 4 is displayed by the first positioning instrument 1, and a coordinate conversion matrix is ​​obtained. Inverse it to obtain the coordinate conversion matrix required for converting the display coordinates on the first locator 1 to the first single-sided marked bridge 4

[0077] The coordinate transformation matrix is ​​obtained by displaying the first single-sided marked bridge object 4 by the second positioning instrument 2 image. Inverse it to obtain the coordinate conversion matrix required for converting the display coordinates on the second locator 2 to the first single-sided marked bridge 4

[0078] For the first placement method, the third positioning device 3 displays the second single-sided marked bridge 5, and obtains the coordinate transformation matrix and the real coordinates of the front mark of the double-sided marked bridge object 6 in the coordinate system of the third locator 3 (that is, the real coordinates of the second single-sided marked bridge object 5 in the coordinate system of the third locator 3), the coordinate conversion matrix Perform inversion to obtain the coordinate conversion matrix required for converting the display coordinates on the third locator 3 to the second single-sided marked bridge object 5 Using the three locator positions determined in step 2, according to the coordinates of the first single-sided marked bridge object 4 and the second single-sided marked bridge object 5 in the coordinate system of the second locator 2, the coordinate transformation matrix is ​​obtained: Then, the matrix required for converting the coordinates displayed on the third positioning device 3 to the first single-sided marked bridge object 4 is obtained. for:

[0079]

[0080] For the second placement method, the third positioning device 3 displays the reverse mark of the double-sided marked bridge 6, and obtains the coordinate transformation matrix and the real coordinates of the reverse side mark of the double-sided mark bridge 6 in the coordinate system of the third positioning device 3, and the coordinate conversion matrix Perform inversion to obtain the coordinate conversion matrix required for converting the display coordinates on the third locator 3 to the reverse side mark of the double-sided mark bridge 6 Since the thickness of the double-sided marked bridge 6 and the real coordinates of the front and back marks of the double-sided marked bridge 6 in the coordinate system of the third positioning device 3 are known values, the coordinate transformation matrix from the back coordinate system to the front coordinate system of the double-sided marked bridge 6 is obtained as follows: According to the coordinates of the first single-sided marked bridge object 4 and the second single-sided marked bridge object 5 in the coordinate system of the second positioning device 2, the coordinate conversion matrix is ​​obtained: Then, the matrix required for converting the coordinates displayed on the third positioning device 3 to the first single-sided marked bridge object 4 is obtained. for:

[0081]

[0082] At this point, all the point information on the three locators is unified into the coordinate system of the first single-sided marked bridge object 4, which not only avoids the error caused by the movement of the locators during the measurement process, but also avoids the conversion error between the marked bridge objects because of the relative fixity.

[0083] Step 5. Use the marking probe 8 to measure the distance within the ranging range of the system: the marking probe 8 enters the field of view of any locator, and the locator completes the recognition of the end mark of the marking probe 8; then the tip of the marking probe 8 is placed on the two positions where the distance needs to be measured, and the buttons for capturing the starting point, capturing the end point and calculating the distance on the ranging software interface are clicked respectively to perform geometric calculations and complete the ranging.

[0084] Preferably, in step 5, while completing the identification of the end mark of the marking probe 8, the end mark is displayed in a color change in the field of view of the locator, and the handheld device button corresponding to the marking probe 8 in the interface of the ranging software will change color and flash, further confirming that the identification is successful.

[0085] Preferably, in step 5, the geometric calculation includes the straight-line distance, the projection distance and the relative coordinates between the two location points.

[0086] Preferably, in step 5, the calculation formula for the straight-line distance between two position points is:

[0087]

[0088] In formula (3), h is the straight-line distance between two points, x1 is the horizontal coordinate of the first point, y1 is the vertical coordinate of the first point, z1 is the vertical coordinate of the first point, x2 is the horizontal coordinate of the second point, y2 is the vertical coordinate of the second point, and z2 is the vertical coordinate of the second point.

[0089] Preferably, in step 5, the calculation formula for the projection distance between two position points is:

[0090] h c =h·cosα·sinθ

[0091] h k =h·cosα·cosθ

[0092] h g =h·sinα (4)

[0094] In formula (4), h c h is the distance between two points first projected onto the XOY plane and then onto the y-axis, i.e., the projection length. k h is the distance between two points first projected onto the XOY plane and then onto the x-axis, i.e. the projection width. g is the distance between the two position points projected to the z-axis, i.e., the projection height; α is the angle between the spatial straight line and the XOY plane; and θ is the angle between the projected straight line on the XOY plane and the x-axis.

[0095] Preferably, in step 5, the relative coordinates between the two position points are calculated by performing a subtraction operation on the three-dimensional coordinates of the two points to obtain the three-dimensional coordinates of the end point relative to the starting point.

[0096] Preferably, in step 5, the position point selection and distance measurement operation are directly performed on the distance measurement software interface, and the straight-line distance between the two position points is measured. Three distance buttons are set for the measurement of projection distance. First click the projection length button and then select and measure the position point. The distance between the two position points first projected to the XOY plane and then projected to the y-axis is measured; first click the projection width button and then select and measure the position point. The distance between the two position points first projected to the XOY plane and then projected to the x-axis is measured; first click the projection height button and then select and measure the position point. The distance between the two position points projected to the z-axis is measured.

[0097] Preferably, the method also includes step 6: the software development simultaneously sets the initialization and storage file output functions. After measuring the straight-line distance between two position points, the coordinate information of the two position points can be copied to the next line, and the distance button can be clicked to directly obtain the projection distance. The selection operation for different distance requirements is simplified. After each set of tests, the measurement data can be exported, and the interface can be initialized at the same time to perform the next set of test operations.

[0098] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A large-scale multi-locator spatial ranging system based on visible light, characterized in that: The system comprises three locators, three marking bridges, a level (7), a marking probe (8) and a computer; the three locators are a first locator (1), a second locator (2) and a third locator (3); The three marking bridges are a first single-sided marking bridge (4), a second single-sided marking bridge (5) and a double-sided marking bridge (6); The first single-sided marked bridge (4) and the second single-sided marked bridge (5) are provided with at least three marks on the front side, the distance between any two marks on the same side is different, and no marks are provided on the back side; the double-sided marked bridge (6) is provided with at least three marks on both the front side and the back side, and the distance between any two marks on the same side is different; The marking arrangement on the front side of the double-sided marking bridge (6) is the same as that on the front side of the second single-sided marking bridge (5), and the marking arrangement on the back side is different from that on the first single-sided marking bridge (4) and the second single-sided marking bridge (5); at least three markings are arranged on the front side of the end of the marking probe (8), the distances between any two markings are different, and no marking is arranged on the back side; the marking probe (8) is used to measure the distance within the distance measurement range of the system; A level (7) is installed on the first single-sided marking bridge (4); distance measuring software is installed in the computer; the first positioning instrument (1), the second positioning instrument (2) and the third positioning instrument (3) are connected to the computer for communication; the three positioning instruments are placed at intervals, and there are two placement methods: The first placement mode: the three locators are all placed on the same side, and are, from left to right, the first locator (1), the second locator (2) and the third locator (3), respectively. The first locator (1) and the third locator (3) have an inclined angle relative to the vertical plane; the first single-sided marking bridge (4) is located between the first locator (1) and the second locator (2), and is located within the field of view of the first locator (1) and the second locator (2); The second single-sided marking bridge (5) is located between the second locator (2) and the third locator (3), and is located within the field of view of the second locator (2) and the third locator (3); The second arrangement mode: from left to right, the first locator (1), the second locator (2) and the third locator (3) are arranged in order, the first locator (1) and the second locator (2) are arranged on the same side, the third locator (3) is placed on the opposite side of the first locator (1) and the second locator (2), and the third locator (3) is arranged in the opposite direction, the first locator (1) has an inclined angle relative to the vertical plane; the first single-sided marking bridge (4) is located between the first locator (1) and the second locator (2), and is located within the field of view of the first locator (1) and the second locator (2); The double-sided marking bridge (6) is located between the second locator (2) and the third locator (3), and the front side of the double-sided marking bridge (6) is located within the field of view of the second locator (2), and the back side is located within the field of view of the third locator (3).

2. The distance measurement system according to claim 1, characterized in that: The first locator (1), the second locator (2) and the third locator (3) all adopt binocular camera optical locators.

3. The distance measurement system according to claim 1, characterized in that: The mark adopts a closed shape; the color of the mark and the color of the main body of the three mark bridges are selected based on the following criteria: the contrast between the two is the strongest and the color difference is the largest.

4. The distance measurement system according to claim 1, characterized in that: In the first placement mode, the inclination angles of the first locator (1) and the third locator (3) relative to the vertical plane are 0 to 45°; in the second placement mode, the inclination angle of the first locator (1) relative to the vertical plane is 0 to 45°.

5. A large-scale multi-locator spatial distance measurement method based on visible light, characterized in that: The method comprises the following steps: Step 1, constructing the ranging system described in any one of claims 1 to 4; Step 2: Determine the positions of the three locators and the three marked bridges: For the first placement method, the display image of the first single-sided marked bridge (4) of the first locator (1) is moved to the rightmost end of the field of view, ensuring that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge (4) and the second single-sided marked bridge (5) are respectively placed at the leftmost end and the rightmost end of the field of view of the second locator (2), thereby fixing the positions of the first single-sided marked bridge (4) and the second single-sided marked bridge (5); the display image of the second single-sided marked bridge (5) of the third locator (3) is moved to the leftmost end of the field of view, ensuring that the field of view from the rightmost end is included in the distance measurement range of the system; For the second placement method, the display image of the first single-sided marked bridge (4) of the first locator (1) is moved to the rightmost end of the field of view, ensuring that the field of view from the leftmost end is included in the distance measurement range of the system; the positions of the first single-sided marked bridge (4) and the double-sided marked bridge (6) are respectively placed at the leftmost end and the rightmost end of the field of view of the second locator (2), thereby fixing the positions of the first single-sided marked bridge (4) and the double-sided marked bridge (6); the display image of the third locator (3) for the double-sided marked bridge (6) is moved to the leftmost end of the field of view, ensuring that the field of view from the rightmost end is included in the distance measurement range of the system; Step 3, the locator identifies and distinguishes the marker bridge and the marker probe (8): After the arrangement is completed, two marker bridges appear in the field of view of the second locator 2 in each arrangement mode, and the instrument fusion algorithm is used to realize the identification of each marker bridge and marker probe (8) and the distinction between different marker bridges and marker probes (8); Step 4: Unify the coordinate system and transform the coordinates: For the first placement method, the first positioning instrument (1) and the third positioning instrument (3) are respectively moved to the position of the second positioning instrument (2), and double bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object (4) and the second single-sided marked bridge object (5), and then the first positioning instrument (1) and the third positioning instrument (3) are moved to the corresponding positions of their respective placement methods in step 2; For the second placement method, the first positioning instrument (1) and the third positioning instrument (3) are respectively moved to the position of the second positioning instrument (2), and double-bridging operations are performed in sequence to obtain the coordinate conversion matrix of the first single-sided marked bridge object (4) and the double-sided marked bridge object (6); then the first positioning instrument (1) and the third positioning instrument (3) are moved to the corresponding positions of their respective placement methods in step 2, and the third positioning instrument (3) is subjected to triple-bridging operations to establish a coordinate conversion matrix for the third positioning instrument (3) from the back side of the double-sided marked bridge object (6) to the front side and then to the first single-sided marked bridge object (4); Step 5: Use the marking probe (8) to measure the distance within the system's ranging range: the marking probe (8) enters the field of view of any locator, and the locator recognizes the end mark of the marking probe (8); then the tip of the marking probe (8) is placed at two positions where the distance needs to be measured, and geometric calculations are performed to complete the ranging.

6. The distance measurement method according to claim 5, characterized in that: In step 3, the specific steps of the instrument fusion algorithm are as follows: S31, storing the center coordinates of all the marks of the three marking bridges and the marking probe (8) in the real space in the coordinate system of the second positioning device (2) as element information in the matrix P1; numbering the centers of all the marks on each marking bridge and the marking probe (8) in sequence, and obtaining the center distance between adjacent numbers, and storing this distance value as element information in the matrix P2; Using the size information of the maximum closed boundary contour of the marker as a specific threshold, an image feature extraction algorithm is used to extract all closed boundary contours that meet the specific threshold range in the field of view of the second locator (2) to obtain contour points; the contour points include the corresponding contour points of all markers of the first single-sided marker bridge (4), the second single-sided marker bridge (5), the double-sided marker bridge (6) and the marker probe (8) in the field of view, and other redundant contour points generated by clutter that meet the specific threshold range and have closed boundaries; all contour points are then sorted and traversed by a stereo matching algorithm, and the contour points of the left and right cameras of each locator are fitted and judged to complete the one-to-one matching of the left and right contour points; the center coordinates of the matched contour points are then stored as element information in a matrix P3, and the matched contour points are numbered in sequence, and the center distances of adjacent numbers are obtained, and the distance values ​​are stored as element information in a matrix P4; S32, using the distance information in the matrix P2 as the discrimination threshold, traversing the element information in the matrix P4 in turn, screening out the distance values ​​less than the discrimination threshold, and then determining the corresponding contour points of the marker bridge and the marker probe (8) in the contour points, completing the fusion process of the marker in the real space and the corresponding contour points discriminated using the distance information, and then reconstructing the markers of each marker bridge and marker probe (8) in the locator; S33. Detect the marker probe (8) and each marker bridge separately, and record the detection information. Perform PCA dimensionality reduction algorithm or ICP algorithm on the coordinate information of the marker reconstructed by each marker bridge and marker probe (8) and the coordinate information of the marker in the real space to obtain the transformation matrix, so as to realize the registration of the corresponding contour points, and then identify and distinguish different marker bridges and marker probes (8).

7. The distance measurement method according to claim 6, characterized in that: In step S33, for the marking probe (8), the measuring point is selected by the contact of its tip during measurement, so the tip needs to be calibrated. The specific steps are as follows: S331, ensuring that the spatial position of the tip of the marking probe (8) is fixed relative to the first positioning instrument (1), recording the coordinate position P5 of the tip in the coordinate system of the first positioning instrument (1), and the coordinate position of the tip of the marking probe (8) to the end mark in the coordinate system is P6; S332, continuously rotating the marking probe (8), and collecting the coordinate transformation matrix from the coordinate system of the end mark of the marking probe (8) to the coordinate system of the first positioning instrument (1) through a rotation calibration data collection process; S333. By differentiating and organizing the coordinate transformation matrix, a matrix composed of the coordinate position information in P5 and P6 is obtained to obtain the local coordinate position from the tip of the marking probe (8) to the end mark, so as to realize the recognition of the marking probe (8) by the locator.

8. The distance measurement method according to claim 5, characterized in that: In step 4, both the double-bridge operation and the triple-bridge operation use the pose solving algorithm; the specific conversion process of pose solving is as follows: S41, the coordinate system of the first single-sided marked bridge (4) is represented as d1, the coordinate systems of the front sides of the second single-sided marked bridge (5) and the double-sided marked bridge (6) are represented as d2, and the coordinate system of the back side of the double-sided marked bridge (6) is represented as d3; the coordinate system of the first locator (1) is represented as m1, the coordinate system of the second locator (2) is represented as m2, and the coordinate system of the third locator (3) is represented as m3; S42, using the first locator (1) to display the first single-sided marked bridge (4) to obtain a coordinate conversion matrix The inverse is calculated to obtain the coordinate conversion matrix required for converting the display coordinates on the first positioning device (1) to the first single-sided marking bridge (4). The coordinate conversion matrix is ​​obtained by displaying the first single-sided marked bridge object (4) by the second positioning instrument (2) image. The coordinate conversion matrix required for converting the displayed coordinates on the second positioning device (2) to the first single-sided marking bridge (4) is obtained by inverting the coordinates. For the first placement method, the third positioning device (3) displays the second single-sided marked bridge (5) to obtain a coordinate conversion matrix and the real coordinates of the front mark of the double-sided mark bridge (6) in the coordinate system of the third positioning device (3), and the coordinate conversion matrix Perform inversion to obtain the coordinate conversion matrix required for converting the display coordinates on the third positioning device (3) to the second single-sided marking bridge (5). Using the three locator positions determined in step 2, according to the coordinates of the first single-sided marked bridge object (4) and the second single-sided marked bridge object (5) in the coordinate system of the second locator (2), a coordinate transformation matrix is ​​obtained: Then, the matrix required for converting the display coordinates on the third positioning device (3) to the first single-sided marked bridge (4) is obtained. for: For the second placement method, the coordinate conversion matrix is ​​obtained by displaying the reverse side mark of the double-sided marked bridge (6) through the image of the third positioning device (3): and the real coordinates of the reverse side mark of the double-sided mark bridge (6) in the coordinate system of the third positioning device (3), and the coordinate conversion matrix Perform inversion to obtain the coordinate conversion matrix required for converting the display coordinates on the third positioning device (3) to the reverse side mark of the double-sided mark bridge (6). Since the thickness of the double-sided mark bridge (6) and the real coordinates of the front and back marks of the double-sided mark bridge (6) in the coordinate system of the third positioning device (3) are known values, the coordinate transformation matrix from the back coordinate system to the front coordinate system of the double-sided mark bridge (6) is obtained as follows: According to the coordinates of the first single-sided marked bridge (4) and the second single-sided marked bridge (5) in the coordinate system of the second positioning device (2), a coordinate conversion matrix is ​​obtained. Then, the matrix required for converting the display coordinates on the third positioning device (3) to the first single-sided marked bridge (4) is obtained. for: At this point, all the point information on the three positioning devices is unified into the coordinate system of the first single-sided marked bridge (4).

9. The distance measurement method according to claim 5, characterized in that: In step 5, the geometric calculation includes the straight-line distance, projection distance and relative coordinates between two location points.

10. The distance measurement method according to claim 9, characterized in that: In step 5, the straight-line distance between two locations is calculated as: In formula (3), h is the straight-line distance between two points, x1 is the horizontal coordinate of the first point, y1 is the vertical coordinate of the first point, z1 is the vertical coordinate of the first point, x2 is the horizontal coordinate of the second point, y2 is the vertical coordinate of the second point, and z2 is the vertical coordinate of the second point; The calculation formula for the projection distance between two location points is: h c =h·cosα·sinθ h k =h·cosα·cosθ h g =h·sinα (4) In formula (4), h c h is the distance between two points first projected onto the XOY plane and then onto the y-axis, i.e., the projection length. k h is the distance between two points first projected onto the XOY plane and then onto the x-axis, i.e. the projection width. g is the distance between the two position points projected to the z-axis, i.e., the projection height; α is the angle between the spatial straight line and the XOY plane; θ is the angle between the projected straight line on the XOY plane and the x-axis; The relative coordinates between two position points are calculated by subtracting the three-dimensional coordinates of the two points to obtain the three-dimensional coordinates of the end point relative to the starting point.

Images