A Networked Measurement Method for Laser Trackers Based on Dynamic Weights

Abstract

This application relates to a network measurement method for laser trackers based on dynamic weights. The method includes: after sending a measurement trigger command to multiple laser trackers, acquiring measurement data from the multiple laser trackers; based on the measurement data from the multiple laser trackers, determining multiple first coordinates of a target reflector and the dynamic weights of the multiple laser trackers; the first coordinates are the coordinates of the target reflector in the tracker's Cartesian coordinate system of the corresponding laser tracker; transforming the multiple first coordinates based on the spatial transformation relationship between the tracker's Cartesian coordinate system and the world Cartesian coordinate system to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector measured by the corresponding laser tracker in the world Cartesian coordinate system; and determining the target's three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and the multiple second coordinates. This method enables high-precision three-dimensional coordinate measurement of the target reflector.

Description

Technical Field

[0001] This application relates to the field of measurement technology, and in particular to a network measurement method for laser trackers based on dynamic weights. Background Technology

[0002] A laser tracker is a high-precision three-dimensional coordinate measuring instrument widely used in industrial fields such as aerospace, automotive manufacturing, robot calibration, and large equipment assembly. A typical laser tracker works by emitting a laser beam to track a target reflector (such as a target sphere), acquiring the linear distance and combined angles to measure the three-dimensional coordinates of a point in space.

[0003] In current industrial practice, the most common method is to use a single laser tracker for measurement. However, the coordinate measurement accuracy of a single tracker is determined by both linear distance accuracy and angular accuracy. According to the principle of similar triangles, the distance error caused by angular error increases linearly with the increase of linear distance. As the size of the workpiece being measured continues to increase and the measurement accuracy requirements continue to rise, the measurement error, after being amplified over long distances, will lead to a high coordinate deviation, far exceeding the tolerance range allowed in many precision workpiece measurement scenarios. Therefore, current single-laser tracker measurement methods are difficult to maintain high-precision three-dimensional coordinate measurement on a scale of tens of meters. Summary of the Invention

[0004] Therefore, it is necessary to provide a dynamic weight-based laser tracker network measurement method, device, computer equipment, computer-readable storage medium, and computer program product that can achieve high-precision three-dimensional coordinate measurement of target reflectors, addressing the aforementioned technical problems.

[0005] Firstly, this application provides a laser tracker network measurement method based on dynamic weights, including:

[0006] After sending measurement trigger commands to multiple laser trackers, measurement data from multiple laser trackers is acquired; the measurement trigger commands are used to control each laser tracker to emit laser beams toward the target reflector, and the measurement data is generated based on the reflected beams corresponding to the laser beams;

[0007] Based on measurement data from multiple laser trackers, multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers are determined; the first coordinates are the coordinates of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker.

[0008] Based on the spatial transformation relationship between the tracker's Cartesian coordinate system and the world Cartesian coordinate system, multiple first coordinates are transformed to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector in the world Cartesian coordinate system as measured by the laser tracker.

[0009] Based on the dynamic weights of each laser tracker and multiple second coordinates, the target three-dimensional coordinates of the target reflector are determined.

[0010] Secondly, this application also provides a laser tracker network measurement device based on dynamic weights, comprising:

[0011] The acquisition module is used to acquire measurement data from multiple laser trackers after sending measurement trigger commands to multiple laser trackers; the measurement trigger commands are used to control each laser tracker to emit laser beams toward the target reflector respectively, and the measurement data is generated based on the reflected beams corresponding to the laser beams;

[0012] The first determining module is used to determine multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers based on the measurement data of multiple laser trackers; the first coordinates are the coordinates of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker;

[0013] The transformation module is used to transform multiple first coordinates based on the spatial transformation relationship between the tracker's Cartesian coordinate system and the world Cartesian coordinate system to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector in the world Cartesian coordinate system;

[0014] The second determining module is used to determine the target three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates.

[0015] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement some or all of the steps described in any method of the first aspect of the embodiments of this application.

[0016] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements some or all of the steps described in any method of the first aspect of the embodiments of this application.

[0017] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements some or all of the steps described in any method of the first aspect of the embodiments of this application.

[0018] The aforementioned method, apparatus, computer equipment, computer-readable storage medium, and computer program product based on dynamic weighted laser tracker network measurement, since the dynamic weights of multiple laser trackers are determined by the measurement data of multiple laser trackers, and the target three-dimensional coordinates of the target reflector are determined by the dynamic weights of multiple laser trackers, the method provided in this embodiment can effectively suppress the measurement error amplification effect that may occur during the measurement process of a single laser tracker. Therefore, it can achieve high-precision three-dimensional coordinate measurement of the target reflector, that is, it can ensure that the measured target three-dimensional coordinates of the target reflector have high accuracy. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 An application environment diagram for a laser tracker network measurement method based on dynamic weights provided in this application embodiment;

[0021] Figure 2 A flowchart illustrating a laser tracker network measurement method based on dynamic weights, provided for an embodiment of this application;

[0022] Figure 3 A flowchart illustrating another laser tracker network measurement method based on dynamic weights provided in this application embodiment;

[0023] Figure 4 A structural block diagram of a laser tracker network measurement device based on dynamic weights provided in this application embodiment;

[0024] Figure 5 This is an internal structural diagram of a computer device in one embodiment;

[0025] Figure 6 This is a diagram of the internal structure of a computer device in another embodiment. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] The laser tracker network measurement method based on dynamic weights provided in this application can be applied to, for example... Figure 1 In the application environment shown, the host computer 102 is connected to multiple laser trackers 104. Each laser tracker 104 includes a laser measurement unit 1042. Based on this, the laser tracker 104 can emit a laser beam towards the target reflector 106 through the laser measurement unit 1042 and receive the reflected beam reflected by the target reflector 106. The laser tracker 104 determines the measurement data based on the reflected beam and transmits the measurement data to the host computer 102. The host computer 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, etc., and is not limited to these. The host computer 102 can also be a hardware controller, such as a hardware synchronization trigger.

[0028] In one exemplary embodiment, such as Figure 2 As shown, a method for networked measurement of laser trackers based on dynamic weights is provided, which is then applied to... Figure 1 Taking the host computer as an example, the explanation includes the following steps 202 to 208. Wherein:

[0029] Step 202: After sending measurement trigger commands to multiple laser trackers, measurement data from multiple laser trackers is acquired; the measurement trigger commands are used to control each laser tracker to emit laser beams toward the target reflector respectively, and the measurement data is generated based on the reflected beams corresponding to the laser beams.

[0030] Optionally, the number of laser trackers can be two, three, four, six, or other numbers.

[0031] Optionally, multiple laser trackers can have the same model number.

[0032] Optionally, the measurement trigger command can be a command triggered by the user on the host computer and sent to the laser tracker. Multiple laser trackers will receive the measurement trigger command simultaneously, so that they will emit laser beams toward the target reflector at the same time.

[0033] A target reflector is a reflector that is placed on the object to be tracked and can reflect the laser beam from the laser tracker back along its original path.

[0034] Alternatively, the target reflector can be a target sphere or a corner prism.

[0035] A reflected beam is a laser beam emitted by a laser tracker that is reflected by the target reflector, then reflected along its original path and received by the laser tracker.

[0036] Step 204: Based on the measurement data of multiple laser trackers, determine multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers; the first coordinates are the coordinates of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker.

[0037] Each laser tracker has its own Cartesian coordinate system. Each laser tracker will determine the coordinates of the target reflector in its own Cartesian coordinate system. Therefore, the number of first coordinates corresponds to the number of laser trackers.

[0038] For example, if there are four laser trackers, then the number of first coordinates is also four.

[0039] Optionally, the measurement data of the laser tracker may include the straight-line distance and angle between the laser tracker and the target reflector; further optionally, the angle may include the horizontal angle and the pitch angle.

[0040] The straight-line distance between the laser tracker and the target reflector refers to the straight-line length of space between the center of the laser tracker and the reflection center of the target reflector. In simple terms, this straight-line distance is the shortest distance between the laser tracker and the target reflector.

[0041] Optionally, the tracking center of the laser tracker refers to the center of the laser measurement unit of the laser tracker.

[0042] Optionally, the reflection center of the target reflector may refer to the geometric center of the target reflector.

[0043] Optionally, the straight-line distance between the laser tracker and the target reflector can be measured by a laser interferometric ranging module or an absolute ranging module installed in the laser tracker. Based on this, the straight-line distance can be understood as the straight-line distance between the laser tracker and the target reflector as actually measured by the laser tracker.

[0044] The horizontal angle between the laser tracker and the target reflector refers to the angle between the laser tracker's preset reference direction and the projection direction of the target reflector on the horizontal plane, within the horizontal plane.

[0045] The pitch angle between the laser tracker and the target reflector refers to the angle between the direction of the laser beam emitted by the laser tracker and the horizontal plane.

[0046] Optionally, the angle between the laser tracker and the target reflector can be measured using a high-precision angle encoder installed in the laser tracker. A high-precision angle encoder can also be called a circular grating.

[0047] Based on the straight-line distance and angle between multiple laser trackers and the target reflector, i.e., the three sets of raw data (straight-line distance d) measured by each laser tracker. i Horizontal angle α i Pitch angle β iTogether, they determined the three-dimensional polar coordinates of the target reflector. After coordinate transformation, the spatial coordinates of the target reflector in the tracker's own Cartesian coordinate system can be obtained, denoted as G. i =(X Si Y Si Z Si Where G indicates that the coordinate is located in the laser tracker's own coordinate system, the subscript i distinguishes different trackers, and X... Si Y Si Z Si These are the three axial coordinate components of the target reflector in the coordinate system of the i-th laser tracker. The multiple first coordinates of the target reflector can be used to provide a basis for subsequent coordinate system unification and coordinate fusion.

[0048] Since the straight-line distance and angle between each laser tracker and the target reflector may be different, and the measurement accuracy of each individual laser tracker also varies, in order to reasonably reflect the reliability of the measurement data of each laser tracker when determining the target three-dimensional coordinates of the target reflector, it is necessary to determine the dynamic weight of each laser tracker based on the measurement data of each laser tracker.

[0049] Step 206: Based on the spatial transformation relationship between the tracker's rectangular coordinate system and the world rectangular coordinate system, transform multiple first coordinates to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector measured by the laser tracker in the world rectangular coordinate system.

[0050] Since the second coordinate is obtained by transforming the first coordinate, the number of first coordinates corresponds to the number of second coordinates.

[0051] The world rectangular coordinate system is a unified reference coordinate system that can be used to describe the absolute position of objects in the entire measurement environment, including multiple laser trackers and target transmitters. The world rectangular coordinate system can also be called an absolute coordinate system.

[0052] Spatial transformation relationship refers to the three-dimensional rigid body transformation relationship between the tracker's Cartesian coordinate system and the world Cartesian coordinate system. Optionally, the spatial transformation relationship can be obtained by calibrating a common target in the measurement environment and solving it through multiple laser trackers. Furthermore, the spatial transformation relationship can be jointly characterized by two sets of parameters: rotation matrix and translation vector. Based on this, the first coordinate in the tracker's Cartesian coordinate system can be uniformly transformed to the second coordinate in the world Cartesian coordinate system through the spatial transformation relationship.

[0053] Step 206 involves transforming the multiple first coordinates, each located in the corresponding tracker's Cartesian coordinate system, to a unified world Cartesian coordinate system. In other words, the world Cartesian coordinate system includes multiple second coordinates K corresponding to the number of laser trackers. i = (X Si Y Si Z Si ), where K indicates that the coordinate is located in the world rectangular coordinate system.

[0054] Step 208: Determine the target three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates.

[0055] Since there is a one-to-one correspondence between the second coordinate and the laser tracker, the second coordinate of the laser tracker with a larger dynamic weight has a greater determining effect on the target three-dimensional coordinate of the target reflector.

[0056] Optionally, based on the dynamic weights of each laser tracker and multiple second coordinates, a weighted average method can be used to calculate the target three-dimensional coordinates of the reflector. That is, the target three-dimensional coordinates can be obtained by weighting and summing the first, second, and third direction components of the multiple second coordinates based on the dynamic weights of each laser tracker, and then dividing by the sum of the dynamic weights of the multiple laser trackers. If the sum of the dynamic weights of the multiple laser trackers is 1, then the target three-dimensional coordinates of the reflector can be obtained directly by weighting and summing the first, second, and third direction components of the multiple second coordinates based on the dynamic weights of each laser tracker.

[0057] In an exemplary embodiment, the above-mentioned determination of multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers based on measurement data from multiple laser trackers includes: determining multiple first coordinates of the target reflector and the initial dynamic weights of the multiple laser trackers based on measurement data from multiple laser trackers; and normalizing the initial dynamic weights of the multiple laser trackers to obtain the dynamic weights of the multiple laser trackers.

[0058] Optionally, the first directional component refers to the X component of the corresponding coordinate; the second directional component refers to the Y component of the corresponding coordinate; and the third directional component refers to the Z component of the corresponding coordinate.

[0059] Since the dynamic weights of each laser tracker are determined based on the measurement data of each laser tracker, each laser tracker will have different dynamic weights in each measurement process due to the different measurement data. Based on this, the target three-dimensional coordinates of the target reflector obtained in each measurement will always be more inclined to the second coordinates corresponding to the laser tracker with a larger dynamic weight. Thus, the measurement error amplification effect that may be caused by fixed weights is avoided by using dynamic weights, thereby improving the accuracy of the target three-dimensional coordinates of the target reflector obtained in the measurement.

[0060] In the above-mentioned laser tracker network measurement method based on dynamic weights, since the dynamic weights of multiple laser trackers are determined by the measurement data of multiple laser trackers, and the target three-dimensional coordinates of the target reflector are determined by the dynamic weights of multiple laser trackers, the method provided in this embodiment can effectively suppress the measurement error amplification effect that may occur during the measurement process of a single laser tracker. Thus, it can achieve high-precision three-dimensional coordinate measurement of the target reflector, that is, it can ensure that the measured target three-dimensional coordinates of the target reflector have high precision.

[0061] In an exemplary embodiment, determining the target three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates includes:

[0062] Based on the dynamic weights of each laser tracker and multiple second coordinates, the initial three-dimensional coordinates of the target reflector are determined;

[0063] Based on multiple measurement data, the position coordinates of each laser tracker in the world rectangular coordinate system, and the initial three-dimensional coordinates, the target three-dimensional coordinates of the target reflector are determined.

[0064] Optionally, based on the dynamic weights of each laser tracker and multiple second coordinates, the initial three-dimensional coordinates of the target reflector can be calculated using a weighted average method.

[0065] Since the target three-dimensional coordinates of the target reflector are determined based on multiple measurement data, the position coordinates of each laser tracker in the world rectangular coordinate system, and the initial three-dimensional coordinates, the target three-dimensional coordinates further take into account the measurement data of multiple laser trackers compared with the initial three-dimensional coordinates. Therefore, the target three-dimensional coordinates are superior to the initial three-dimensional coordinates in terms of accuracy and reliability.

[0066] In this embodiment, since the initial three-dimensional coordinates of the target reflector comprehensively consider the measurement data of all laser trackers, the initial three-dimensional coordinates of the target reflector can effectively suppress the random errors of a single laser tracker. Based on this, it can provide a good initial value for subsequent iterative optimization of the target three-dimensional coordinates, so as to ensure that the measured target three-dimensional coordinates of the target reflector have high accuracy.

[0067] In an exemplary embodiment, determining the initial three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates includes:

[0068] The weighted sum of the dynamic weights of each laser tracker and the first direction component of the corresponding second coordinate is determined as the first direction coordinate.

[0069] The weighted sum of the dynamic weights of each laser tracker and the corresponding second direction component of the second coordinate is determined as the second direction coordinate.

[0070] The weighted sum of the dynamic weights of each laser tracker and the corresponding third-direction component of the second coordinate is determined as the third-direction coordinate.

[0071] The initial three-dimensional coordinates of the target reflector are determined based on the first direction coordinates, the second direction coordinates, and the third direction coordinates.

[0072] In this embodiment, the sum of the dynamic weights of multiple laser trackers is 1, meaning that the dynamic weights of multiple laser trackers have been normalized. Based on this, the amount of computation required by the host computer in determining the initial three-dimensional coordinates of the target reflector can be reduced, thereby improving the efficiency of determining the initial three-dimensional coordinates.

[0073] By combining the first direction coordinates, the second direction coordinates, and the third direction coordinates, the complete initial three-dimensional coordinates of the target reflector can be obtained.

[0074] For example, suppose there are four laser trackers with dynamic weights of 0.1, 0.2, 0.3, and 0.4 respectively. The first direction component X of the second coordinate of the four laser trackers is... Si If the weights are 1, 2, 3, and 4 respectively, then the weighted sum of the dynamic weights of the four laser trackers and the first direction component of the corresponding second coordinate is determined as the first direction coordinate X. In this case, the first direction coordinate X = 0.1 × 1 + 0.2 × 2 + 0.3 × 3 + 0.4 × 4 = 3. The calculation process for the second direction coordinate Y and the third direction coordinate Z is similar, so it will not be elaborated here.

[0075] In this embodiment, the weighted summation between the dynamic weights of each laser tracker and the corresponding directional components of the second coordinate is determined as the first directional coordinate, the second directional coordinate, and the third directional coordinate in the initial three-dimensional coordinates of the target reflector. Based on this, the initial three-dimensional coordinates of the target reflector can effectively suppress the random errors of a single laser tracker, thereby providing a good initial value for subsequent iterative optimization of the target three-dimensional coordinates, ensuring that the measured target three-dimensional coordinates of the target reflector have high accuracy.

[0076] In an exemplary embodiment, the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; the determination of the target three-dimensional coordinates of the target reflector based on multiple measurement data, the position coordinates of each laser tracker in the world rectangular coordinate system, and the initial three-dimensional coordinates includes:

[0077] Based on the straight-line distances and the position coordinates of each laser tracker in the world rectangular coordinate system, the distance residuals of each laser tracker are determined.

[0078] Based on each angle and the position coordinates of each laser tracker in the world rectangular coordinate system, the angular residual of each laser tracker is determined.

[0079] Based on the distance and angle weights of each laser tracker, the squares of the distance residuals and the squares of the angle residuals are weighted and summed to determine the weighted sum of squared residuals of multiple laser trackers; the distance weights are determined based on the distance accuracy of the corresponding laser tracker, and the angle weights are determined based on the angle accuracy of the corresponding laser tracker.

[0080] Based on the initial three-dimensional coordinates, the coordinates that minimize the weighted sum of squared residuals of multiple laser trackers are determined through iterative solutions, thus obtaining the target three-dimensional coordinates of the target reflector.

[0081] The distance residual of the laser tracker can be understood as the difference between the actual straight-line distance measured by the laser tracker and the theoretical distance between its corresponding position coordinates and the target's three-dimensional coordinates. The position coordinates of the laser tracker refer to its position coordinates in the world rectangular coordinate system, denoted as K. i = (X i Y i Z i ).

[0082] The angular residual of a laser tracker can be understood as the difference between the angle actually measured by the laser tracker and the theoretical angle calculated based on the position coordinates of the laser tracker and the three-dimensional coordinates of the target.

[0083] Optionally, the angular residuals of the laser tracker may include the horizontal angular residuals and the pitch angular residuals of the laser tracker.

[0084] The horizontal angle residual of a laser tracker can be understood as the angle difference between the horizontal angle actually measured by the laser tracker and the theoretical horizontal angle calculated based on the position coordinates of the laser tracker and the three-dimensional coordinates of the target.

[0085] The pitch angle residual of a laser tracker can be understood as the angle difference between the pitch angle actually measured by the laser tracker and the theoretical pitch angle calculated based on the position coordinates of the laser tracker and the three-dimensional coordinates of the target.

[0086] Optionally, the distance weight and angle weight of the laser tracker can be set manually by the user. That is, the user can determine the distance weight based on the distance accuracy of the laser tracker, and similarly, the user can determine the angle weight based on the angle accuracy of the laser tracker.

[0087] Optionally, if the distance accuracy of a laser tracker is greater than its angle accuracy, then the distance weight of that laser tracker is greater than its angle weight; conversely, if the angle accuracy of a laser tracker is greater than its distance weight, then the angle weight of that laser tracker is greater than its distance weight. Of course, this is not limited to this; for the same laser tracker, the distance weight can also be equal to the angle weight.

[0088] For the same laser tracker, the sum of the distance weight and the angle weight is 1. Optionally, since the impact of angle error on the accuracy of the target's three-dimensional coordinates is usually greater than that of straight-line error, for the same laser tracker, the distance weight can be greater than the angle weight. Furthermore, when the angle accuracy is less than or equal to the angle accuracy threshold, i.e., the angle accuracy is too poor, in order to avoid the impact of angle error on the accuracy of the target's three-dimensional coordinates, the angle weight of the corresponding laser tracker can be set to 0. Furthermore, in order to completely avoid the impact of angle error on the accuracy of the target's three-dimensional coordinates, the angle weight of each laser tracker can be set to 0.

[0089] Of course, this is not the only option. When the angular accuracy of the laser tracker is high, a larger angular weight can be assigned to the corresponding laser tracker. That is to say, the angular weight of the corresponding laser tracker can be set to be greater than the distance weight.

[0090] In an exemplary embodiment, when the angular residuals include horizontal angle residuals and pitch angle residuals, the weighted sum of squared residuals from multiple laser trackers is expressed by the following formula:

[0091] (1)

[0092] in, This represents the weighted sum of squared residuals from multiple laser trackers. This represents the distance weight of the i-th laser tracker. This represents the distance residual of the i-th laser tracker. This represents the angle weight of the i-th laser tracker. This represents the horizontal angle residual of the i-th laser tracker. Let represent the pitch angle residual of the i-th laser tracker.

[0093] Alternatively, the Levenberg-Marquardt algorithm can be used to iteratively solve the problem based on the initial three-dimensional coordinates. Within the short-range spatial range of the initial three-dimensional coordinates, the coordinates that minimize the weighted sum of squared residuals of multiple laser trackers can be determined to obtain the target three-dimensional coordinates of the target reflector.

[0094] When the angle weight of the laser tracker is 0, the sum of the angle residuals of the laser tracker, that is, the sum of the squares of the horizontal angle residuals and the squares of the pitch angle residuals, can be automatically removed from the calculation formula of the weighted sum of squares of residuals of multiple laser trackers. Thus, the weighted sum of squares of residuals can be determined only by using the distance weights and distance residuals of multiple laser trackers.

[0095] In this embodiment, the process of determining the target three-dimensional coordinates of the target reflector fully considers the distance residual, distance weight, angle residual, and angle weight of each laser tracker. Therefore, the target three-dimensional coordinates of the target reflector finally determined can comprehensively consider the measurement accuracy differences of all laser trackers, and can ensure that the target three-dimensional coordinates obtained by iterative solution based on the initial three-dimensional coordinates are closest to the optimal three-dimensional coordinates under the real spatial position. Obviously, the accuracy of the target three-dimensional coordinates obtained by the method provided in this embodiment can be greatly improved compared with the measurement results of a single laser tracker.

[0096] In one exemplary embodiment, the distance weight of each laser tracker is greater than the angle weight.

[0097] According to the principle of similar triangles, the distance error caused by the angle error will increase linearly as the straight distance increases. Therefore, setting the distance weight of each laser tracker to be greater than the angle weight can effectively suppress the adverse effects of the angle error on the accuracy of the target's three-dimensional coordinates. This makes the method provided in this embodiment applicable to measurement scenarios where there is a long distance between the laser tracker and the target reflector. Thus, the measurement accuracy and applicability of the method provided in this embodiment are improved.

[0098] In an exemplary embodiment, the angles include horizontal angles and pitch angles, and the angle residuals include horizontal angle residuals and pitch angle residuals;

[0099] The above determination of the angular residuals of each laser tracker, based on various angles and the position coordinates of each laser tracker in the world rectangular coordinate system, includes:

[0100] Based on each horizontal angle and the position coordinates of each laser tracker in the world rectangular coordinate system, determine the horizontal angle residual of each laser tracker;

[0101] Based on each pitch angle and the position coordinates of each laser tracker in the world rectangular coordinate system, determine the pitch angle residual of each laser tracker;

[0102] The sum of the squares of the horizontal angle residuals and the squares of the pitch angle residuals corresponding to each laser tracker is determined as the angle residual of each laser tracker.

[0103] In one exemplary embodiment, the formula for calculating the horizontal angle residual of each laser tracker is as follows:

[0104] (2)

[0105] in, This represents the horizontal angle residual of the i-th laser tracker. This represents the horizontal angle between the i-th laser tracker and the target reflector. This represents the target's three-dimensional coordinates to be solved or the three-dimensional coordinates obtained in the current iteration. This represents the position coordinates of the i-th laser tracker in the world rectangular coordinate system;

[0106] The formulas for calculating the pitch angle residuals of each laser tracker are as follows:

[0107] (3)

[0108] in, This represents the pitch angle residual of the i-th laser tracker. This represents the pitch angle between the i-th laser tracker and the target reflector. This represents the theoretical distance between the position coordinates of the i-th laser tracker and the three-dimensional coordinates of the target. .

[0109] In formula (2) This represents the theoretical horizontal angle calculated based on the position coordinates of the i-th laser tracker in the world rectangular coordinate system and the three-dimensional coordinates of the target.

[0110] In formula (3) This represents the theoretical pitch angle calculated based on the position coordinates of the i-th laser tracker in the world rectangular coordinate system and the three-dimensional coordinates of the target.

[0111] In this embodiment, the horizontal angle residual of each laser tracker is determined based on each horizontal angle and the position coordinates of each laser tracker in the world rectangular coordinate system. Furthermore, the pitch angle residual of each laser tracker is determined based on each pitch angle and the position coordinates of each laser tracker in the world rectangular coordinate system. Thus, the sum of the squares of the horizontal angle residuals and the squares of the pitch angle residuals of each laser tracker is determined as the angular residual of each laser tracker. Based on this, the angular residual of each laser tracker can fully consider the horizontal angle residual and pitch angle residual with respect to the target reflector, ensuring that the final target three-dimensional coordinates of the target reflector have high accuracy.

[0112] In one exemplary embodiment, the formula for calculating the distance residual of each laser tracker is as follows:

[0113] (4)

[0114] in, This represents the distance residual of the i-th laser tracker. This represents the straight-line distance to the target reflector actually measured by the i-th laser tracker. This represents the target's three-dimensional coordinates to be solved or the three-dimensional coordinates obtained in the current iteration. This represents the position coordinates of the i-th laser tracker in the world rectangular coordinate system.

[0115] In one exemplary embodiment, the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector;

[0116] The above-mentioned determination of multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers based on measurement data from multiple laser trackers includes:

[0117] Based on the straight-line distance and angle corresponding to each laser tracker, determine multiple first coordinates of the target reflector;

[0118] The dynamic weights of multiple laser trackers are determined based on the linear distance and / or angle corresponding to each laser tracker.

[0119] Optionally, since laser trackers often have high distance accuracy, the dynamic weight of the laser tracker can be determined using the straight-line distance. However, since the error of the straight-line distance still increases linearly with the increase of the straight-line distance, optionally, when the dynamic weight of each laser tracker is determined only by the corresponding straight-line distance, the dynamic weight of the laser tracker is negatively correlated with the corresponding straight-line distance. Based on this, the dynamic weight of the laser tracker closer to the target reflector can be larger, while the dynamic weight of the laser tracker farther away from the target reflector can be smaller.

[0120] Optionally, since the angular errors of the laser tracker (including horizontal and pitch angle errors) are the main source of lateral coordinate errors, the dynamic weights can be determined using the laser tracker's angles. Because angular errors are amplified as the actual measured angle increases, the angle weights can be negatively correlated with the actual measured angles. Based on this, smaller dynamic weights are assigned to angles that are too large in the laser tracker's measurement data (especially the absolute value of the pitch angle), and larger dynamic weights are assigned to angles that are small (e.g., close to 0°).

[0121] In this embodiment, since the dynamic weights of multiple laser trackers are based on the linear distance and / or angle corresponding to each laser tracker, there is a high degree of correspondence between the dynamic weights and the measurement accuracy of the corresponding laser trackers. That is, the dynamic weights of each laser tracker can fully reflect the measurement accuracy of the corresponding laser tracker. Thus, the process of determining the target three-dimensional coordinates of the target reflector can fully consider the measurement accuracy of each laser tracker. Therefore, the method provided in this embodiment can effectively suppress the measurement error amplification effect that may occur during the measurement process of a single laser tracker. Consequently, it can achieve high-precision three-dimensional coordinate measurement of the target reflector, that is, it can ensure that the measured target three-dimensional coordinates of the target reflector have high accuracy.

[0122] In one exemplary embodiment, the determination of the dynamic weights of multiple laser trackers based on the linear distance and / or angle corresponding to each laser tracker includes at least one of the following:

[0123] The dynamic weights of multiple laser trackers are determined based on the reciprocal of the straight-line distance corresponding to each laser tracker.

[0124] Alternatively, determine the absolute value of the angle corresponding to the angle of each laser tracker, and determine the dynamic weight of multiple laser trackers based on the cosine value of the absolute value of the angle corresponding to each laser tracker.

[0125] Alternatively, the dynamic weights of multiple laser trackers can be determined based on the product of the reciprocal of the straight-line distance corresponding to each laser tracker and the corresponding cosine value.

[0126] In the case where the dynamic weight of the laser tracker is determined solely by the straight-line distance, since the dynamic weight of the laser tracker is based on the reciprocal of the corresponding straight-line distance, there is a negative correlation between the dynamic weight of the laser tracker and the corresponding straight-line distance.

[0127] When the dynamic weights of a laser tracker are determined solely by the angle, since the dynamic weights of multiple laser trackers are based on the absolute values ​​of their corresponding angles, there is a negative correlation between the dynamic weights of the laser trackers and the absolute values ​​of their corresponding angles.

[0128] When the dynamic weight of the laser tracker is determined by the straight-line distance and angle, the dynamic weight can fully take into account the influence of the straight-line distance and angle on the measurement quality of the laser tracker.

[0129] In an exemplary embodiment, when the dynamic weight of the laser tracker is determined solely by the straight-line distance, the formula for calculating the dynamic weight of the laser tracker is as follows:

[0130] (5)

[0131] in, This represents the dynamic weight of the i-th laser tracker, determined solely by straight-line distance. This represents the straight-line distance between the i-th laser tracker and the target reflector.

[0132] Optionally, when the dynamic weights of the laser trackers are determined solely by angles, and when the laser trackers' angles include both horizontal and pitch angles, the cosine of the absolute angle values ​​includes the cosine of both the absolute horizontal and pitch angle values. Based on this, the dynamic weights of multiple laser trackers can be determined by a weighted sum of the cosine values ​​of the absolute horizontal and pitch angle values. Since the pitch angle error of a laser tracker is typically greater than its horizontal angle error, the weight of the cosine of the absolute pitch angle value can be greater than the weight of the cosine of the absolute horizontal angle value.

[0133] In an exemplary embodiment, when the angles of the laser trackers include both horizontal and pitch angles, the above-mentioned determination of the absolute value of the angle corresponding to each laser tracker's angle, and the determination of the dynamic weights of multiple laser trackers based on the cosine value of the absolute value of the angle corresponding to each laser tracker, includes:

[0134] Determine the absolute value of the horizontal angle corresponding to the horizontal angle and the absolute value of the pitch angle corresponding to the pitch angle for each laser tracker;

[0135] Determine the cosine value of the absolute value of the horizontal angle and the cosine value of the absolute value of the pitch angle for each laser tracker.

[0136] The dynamic weights of multiple laser trackers are determined by multiplying the cosine of the absolute value of the horizontal angle corresponding to each laser tracker with the cosine of the absolute value of the pitch angle corresponding to each laser tracker.

[0137] In an exemplary embodiment, where the dynamic weights of the laser tracker are determined solely by angles, including both horizontal and pitch angles, the formula for calculating the dynamic weights of the laser tracker is as follows:

[0138] (6)

[0139] in, This represents the dynamic weight of the i-th laser tracker, determined solely by the angle. This represents the horizontal angle between the i-th laser tracker and the target reflector. This represents the pitch angle between the i-th laser tracker and the target reflector.

[0140] Alternatively, the dynamic weights of the laser tracker can be determined solely by the pitch angle.

[0141] In an exemplary embodiment, when the dynamic weights of the laser tracker are determined solely by the pitch angle, the formula for calculating the dynamic weights of the laser tracker is as follows:

[0142] (7)

[0143] in, This represents the dynamic weight of the i-th laser tracker, determined solely by the angle. This represents the pitch angle between the i-th laser tracker and the target reflector.

[0144] In an exemplary embodiment, where the dynamic weight of the laser tracker is the product of the reciprocal of the straight-line distance and the cosine of the corresponding absolute values ​​of the pitch angle (and horizontal angle), the formula for calculating the dynamic weight of the laser tracker is as follows:

[0145] (8)

[0146] in, The dynamic weight of the i-th laser tracker is determined by the straight-line distance and the pitch angle. This represents the straight-line distance between the i-th laser tracker and the target reflector.

[0147] In this embodiment, the dynamic weight of each laser tracker can be determined solely by the reciprocal of the straight-line distance, or solely by the cosine of the absolute value of the angle, or it can be determined based on the reciprocal of the straight-line distance and the cosine of the absolute value of the angle. Based on this, the determination method of dynamic weight has high flexibility and can take into account the influence of different measurement data on the measurement quality of the laser tracker.

[0148] In an exemplary embodiment, determining the dynamic weights of multiple laser trackers based on the linear distance and / or angle corresponding to each laser tracker includes:

[0149] The initial dynamic weights of multiple laser trackers are determined based on the straight-line distance and / or angle corresponding to each laser tracker.

[0150] Based on the historical usage time of each laser tracker, the weight reduction coefficients of multiple laser trackers are determined; there is a positive correlation between historical usage time and weight reduction coefficients;

[0151] The initial dynamic weights of multiple laser trackers are reduced based on the weight reduction coefficient of each laser tracker to obtain the dynamic weights of multiple laser trackers.

[0152] In this embodiment, when determining the dynamic weights of multiple laser trackers, the historical usage time of each laser tracker can also be taken into account, that is, the aging of each laser tracker, so as to ensure that the dynamic weights of multiple laser trackers have high reliability and accuracy.

[0153] It should be noted that the distance and angle weights of the laser tracker are independent of the laser tracker's measurement data; that is, the distance and angle weights of the laser tracker are not determined by the measurement data. However, the dynamic weights of the laser tracker are determined by the measurement data. Based on this, the initial three-dimensional coordinates of the target reflector are determined by comprehensively considering the measurement data of each laser tracker. The target three-dimensional coordinates of the target reflector are determined based on multiple measurement data, the position coordinates of each laser tracker in the world rectangular coordinate system, and the initial three-dimensional coordinates. Therefore, the target three-dimensional coordinates are determined by comprehensively considering the measurement data and measurement accuracy of each laser tracker. Thus, the method provided in this embodiment can ensure that the measured target three-dimensional coordinates of the target reflector have high accuracy.

[0154] The following detailed embodiment illustrates the application process of the aforementioned dynamic weight-based laser tracker network measurement method. Figure 3 As shown, the details are as follows:

[0155] Step 302: After sending measurement trigger commands to multiple laser trackers, acquire measurement data from multiple laser trackers; the measurement trigger commands are used to control (e.g., synchronous triggering) each laser tracker to emit laser beams toward the target reflector respectively, and the measurement data is generated based on the reflected beams corresponding to the laser beams; the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; the angles include the horizontal angle and the pitch angle.

[0156] Step 304: Determine multiple first coordinates of the target reflector based on the straight-line distance and angle corresponding to each laser tracker.

[0157] Step 306: Determine the dynamic weights of multiple laser trackers based on the straight-line distance and / or angle corresponding to each laser tracker; the first coordinate is the coordinate of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker.

[0158] Step 308: Based on the spatial transformation relationship between the tracker's rectangular coordinate system and the world rectangular coordinate system, multiple first coordinates are transformed to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector measured by the laser tracker in the world rectangular coordinate system.

[0159] Step 310: The weighted sum of the dynamic weights of each laser tracker and the first direction component of the corresponding second coordinate is determined as the first direction coordinate; the weighted sum of the dynamic weights of each laser tracker and the second direction component of the corresponding second coordinate is determined as the second direction coordinate; the weighted sum of the dynamic weights of each laser tracker and the third direction component of the corresponding second coordinate is determined as the third direction coordinate.

[0160] Step 312: Determine the initial three-dimensional coordinates of the target reflector based on the first direction coordinates, the second direction coordinates, and the third direction coordinates.

[0161] Step 314: Based on the straight-line distances and the position coordinates of each laser tracker in the world rectangular coordinate system, determine the distance residual of each laser tracker; based on the horizontal angles and the position coordinates of each laser tracker in the world rectangular coordinate system, determine the horizontal angle residual of each laser tracker; based on the pitch angles and the position coordinates of each laser tracker in the world rectangular coordinate system, determine the pitch angle residual of each laser tracker; the sum of the squares of the horizontal angle residuals and the squares of the pitch angle residuals of each laser tracker is determined as the angle residual of each laser tracker.

[0162] Step 316: Based on the distance weight and angle weight of each laser tracker, the squares of the distance residuals and the squares of the angle residuals are weighted and summed to determine the weighted sum of squared residuals of multiple laser trackers; the distance weight is determined based on the distance accuracy of the corresponding laser tracker, and the angle weight is determined based on the angle accuracy of the corresponding laser tracker.

[0163] Step 318: Based on the initial three-dimensional coordinates, iteratively solve to determine the coordinates that minimize the weighted sum of squared residuals of multiple laser trackers, so as to obtain the target three-dimensional coordinates of the target reflector.

[0164] In this embodiment, since the dynamic weights of multiple laser trackers are determined by the measurement data of multiple laser trackers, the initial three-dimensional coordinates of the target reflector are determined by the dynamic weights of multiple laser trackers. Furthermore, in the process of determining the target three-dimensional coordinates of the target reflector, it is necessary to consider not only the initial three-dimensional coordinates, but also the position coordinates of each laser tracker in the world rectangular coordinate system, the distance weight that reflects the distance accuracy of the laser tracker, and the angle weight that reflects the angle accuracy of the laser tracker. Based on this, the method provided in this embodiment can effectively take into account the measurement accuracy of each laser tracker, thereby effectively suppressing the measurement error amplification effect that may occur during the measurement process of a single laser tracker, so as to ensure that the measured target three-dimensional coordinates of the target reflector have high accuracy.

[0165] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0166] Based on the same inventive concept, this application also provides a dynamic weight-based laser tracker network measurement device for implementing the aforementioned dynamic weight-based laser tracker network measurement method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the dynamic weight-based laser tracker network measurement device provided below can be found in the limitations of the dynamic weight-based laser tracker network measurement method described above, and will not be repeated here.

[0167] In one exemplary embodiment, such as Figure 4 As shown, a laser tracker network measurement device based on dynamic weights is provided, including: an acquisition module 402, a first determination module 404, a conversion module 406, and a second determination module 408, wherein:

[0168] The acquisition module 402 is used to acquire measurement data from multiple laser trackers after sending a measurement trigger command to multiple laser trackers; the measurement trigger command is used to control each laser tracker to emit a laser beam toward the target reflector respectively, and the measurement data is generated based on the reflected beam corresponding to the laser beam.

[0169] The first determining module 404 is used to determine multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers based on the measurement data of multiple laser trackers; the first coordinates are the coordinates of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker.

[0170] The conversion module 406 is used to convert multiple first coordinates based on the spatial transformation relationship between the tracker's rectangular coordinate system and the world rectangular coordinate system to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector in the world rectangular coordinate system as measured by the laser tracker.

[0171] The second determining module 408 is used to determine the target three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates.

[0172] In an exemplary embodiment, the second determining module 408 is specifically used to determine the initial three-dimensional coordinates of the target reflector based on the dynamic weights of each laser tracker and multiple second coordinates; and to determine the target three-dimensional coordinates of the target reflector based on multiple measurement data, the position coordinates of each laser tracker in the world rectangular coordinate system, and the initial three-dimensional coordinates.

[0173] In an exemplary embodiment, the second determining module 408 is specifically used to determine the first direction coordinate by weighted summation between the dynamic weights of each laser tracker and the first direction component of the corresponding second coordinate; to determine the second direction coordinate by weighted summation between the dynamic weights of each laser tracker and the second direction component of the corresponding second coordinate; to determine the third direction coordinate by weighted summation between the dynamic weights of each laser tracker and the third direction component of the corresponding second coordinate; and to determine the initial three-dimensional coordinates of the target reflector based on the first direction coordinate, the second direction coordinate, and the third direction coordinate.

[0174] In an exemplary embodiment, the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; the second determining module 408 is specifically used to determine the distance residual of each laser tracker based on each straight-line distance and the position coordinates of each laser tracker in the world rectangular coordinate system; to determine the angle residual of each laser tracker based on each angle and the position coordinates of each laser tracker in the world rectangular coordinate system; to perform a weighted summation of the squares of the distance residuals and the squares of the angle residuals according to the distance weights and angle weights of each laser tracker, so as to determine the weighted sum of squares of the residuals of multiple laser trackers; the distance weights are determined based on the distance accuracy of the corresponding laser tracker, and the angle weights are determined based on the angle accuracy of the corresponding laser tracker; and the coordinates that minimize the weighted sum of squares of the residuals of multiple laser trackers are determined by iteratively solving based on the initial three-dimensional coordinates, so as to obtain the target three-dimensional coordinates of the target reflector.

[0175] In an exemplary embodiment, the angle includes a horizontal angle and a pitch angle, and the angle residual includes a horizontal angle residual and a pitch angle residual; the second determining module 408 is specifically used to determine the horizontal angle residual of each laser tracker based on each horizontal angle and the position coordinates of each laser tracker in the world rectangular coordinate system; to determine the pitch angle residual of each laser tracker based on each pitch angle and the position coordinates of each laser tracker in the world rectangular coordinate system; and to determine the angle residual of each laser tracker by summing the square of the horizontal angle residual and the square of the pitch angle residual corresponding to each laser tracker.

[0176] In an exemplary embodiment, the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; the first determining module 404 is specifically used to determine multiple first coordinates of the target reflector based on the straight-line distance and angle corresponding to each laser tracker; and to determine the dynamic weights of the multiple laser trackers based on the straight-line distance and / or angle corresponding to each laser tracker.

[0177] In an exemplary embodiment, the first determining module 404 is specifically used to perform at least one of the following: determining the dynamic weights of multiple laser trackers based on the reciprocal of the straight-line distance corresponding to each laser tracker; determining the absolute value of the angle corresponding to the angle of each laser tracker, and determining the dynamic weights of multiple laser trackers based on the cosine value of the absolute value of the angle corresponding to each laser tracker; or, determining the dynamic weights of multiple laser trackers based on the product between the reciprocal of the straight-line distance corresponding to each laser tracker and the corresponding cosine value.

[0178] The modules in the aforementioned dynamic weight-based laser tracker network measurement device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0179] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 5 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data related to a dynamic weight-based laser tracker network measurement method. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a dynamic weight-based laser tracker network measurement method.

[0180] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown, the computer device includes a processor, memory, input / output interfaces, a communication interface, a display unit, and an input device. The processor, memory, and input / output interfaces are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interfaces are used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a dynamic weight-based laser tracker network measurement method. The display unit is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0181] Those skilled in the art will understand that Figure 5 or Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0182] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0183] In one exemplary embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above-described method embodiments.

[0184] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0185] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0186] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 application.

[0187] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A laser tracker network measurement method based on dynamic weights, characterized in that, The method includes: After sending measurement trigger commands to multiple laser trackers, measurement data from the multiple laser trackers is acquired; the measurement trigger commands are used to control each of the laser trackers to emit laser beams toward the target reflector respectively, and the measurement data is generated based on the reflected beam corresponding to the laser beam; the measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; Based on measurement data from multiple laser trackers, multiple first coordinates of the target reflector and dynamic weights of the multiple laser trackers are determined; the first coordinates are the coordinates of the target reflector in the tracker Cartesian coordinate system of the corresponding laser tracker. Based on the spatial transformation relationship between the tracker's Cartesian coordinate system and the world Cartesian coordinate system, multiple first coordinates are transformed to obtain multiple second coordinates of the target reflector; the second coordinates are the coordinates of the target reflector in the world Cartesian coordinate system as measured by the laser tracker; the spatial transformation relationship is obtained by calibrating a common target in the measurement environment and then solving it through multiple laser trackers; The weighted sum of the dynamic weights of each laser tracker and the first direction component of the corresponding second coordinate is determined as the first direction coordinate. The weighted sum of the dynamic weights of each laser tracker and the corresponding second direction component of the second coordinate is determined as the second direction coordinate. The weighted sum of the dynamic weights of each laser tracker and the corresponding third-direction component of the second coordinate is determined as the third-direction coordinate. Based on the first direction coordinates, the second direction coordinates, and the third direction coordinates, the initial three-dimensional coordinates of the target reflector are determined; Based on the straight-line distances and the position coordinates of each laser tracker in the world rectangular coordinate system, the distance residuals of each laser tracker are determined. Based on the angles and the position coordinates of the laser trackers in the world rectangular coordinate system, the angular residuals of the laser trackers are determined. Based on the distance weight and angle weight of each laser tracker, the squares of the distance residuals and the squares of the angle residuals are weighted and summed to determine the weighted sum of squared residuals of the multiple laser trackers; the distance weights are determined based on the distance accuracy of the corresponding laser tracker, and the angle weights are determined based on the angle accuracy of the corresponding laser tracker. Based on the initial three-dimensional coordinates, the coordinates that minimize the weighted sum of squared residuals of the multiple laser trackers are determined through iterative solving to obtain the target three-dimensional coordinates of the target reflector.

2. The method according to claim 1, characterized in that, The target reflector is a target sphere or a corner prism.

3. The method according to claim 1, characterized in that, The sum of the distance weight and the angle weight is 1.

4. The method according to claim 1, characterized in that, The distance weight of each laser tracker is greater than the angle weight.

5. The method according to claim 1, characterized in that, The angles include horizontal angles and pitch angles, and the angle residuals include horizontal angle residuals and pitch angle residuals; The determination of the angular residual of each laser tracker based on the angles and the position coordinates of each laser tracker in the world rectangular coordinate system includes: Based on the horizontal angles and the position coordinates of the laser trackers in the world rectangular coordinate system, determine the horizontal angle residuals of the laser trackers. Based on the pitch angles and the position coordinates of the laser trackers in the world rectangular coordinate system, the pitch angle residuals of the laser trackers are determined. The sum of the squares of the horizontal angle residuals and the squares of the pitch angle residuals corresponding to each laser tracker is determined as the angle residuals of each laser tracker.

6. The method according to claim 5, characterized in that, The formulas for calculating the horizontal angle residuals of each laser tracker are as follows: in, This represents the horizontal angle residual of the i-th laser tracker. This represents the horizontal angle between the i-th laser tracker and the target reflector. This represents the target's three-dimensional coordinates to be solved or the three-dimensional coordinates obtained in the current iteration. This represents the position coordinates of the i-th laser tracker in the world rectangular coordinate system. The formulas for calculating the pitch angle residuals of each laser tracker are as follows: in, This represents the pitch angle residual of the i-th laser tracker. This represents the pitch angle between the i-th laser tracker and the target reflector. This represents the theoretical distance between the position coordinates corresponding to the i-th laser tracker and the three-dimensional coordinates of the target. .

7. The method according to claim 1, characterized in that, The formulas for calculating the distance residuals of each laser tracker are as follows: in, This represents the distance residual of the i-th laser tracker. This represents the straight-line distance between the i-th laser tracker and the target reflector, as actually measured. This represents the target's three-dimensional coordinates to be solved or the three-dimensional coordinates obtained in the current iteration. This represents the position coordinates of the i-th laser tracker in the world rectangular coordinate system.

8. The method according to claim 1, characterized in that, The measurement data includes the straight-line distance and angle between the laser tracker and the target reflector; The determination of multiple first coordinates of the target reflector and the dynamic weights of the multiple laser trackers based on measurement data from multiple laser trackers includes: Based on the straight-line distance and angle corresponding to each of the laser trackers, determine multiple first coordinates of the target reflector; The dynamic weights of the laser trackers are determined based on the straight-line distance and / or angle corresponding to each laser tracker.

9. The method according to claim 8, characterized in that, The determination of the dynamic weights of the multiple laser trackers based on the straight-line distance and / or the angle corresponding to each laser tracker includes at least one of the following: The dynamic weights of the laser trackers are determined based on the reciprocal of the straight-line distance corresponding to each laser tracker. Alternatively, determine the absolute value of the angle corresponding to the angle of each laser tracker, and determine the dynamic weight of the multiple laser trackers based on the cosine value of the absolute value of the angle corresponding to each laser tracker; Alternatively, the dynamic weights of the laser trackers can be determined based on the product of the reciprocal of the straight-line distance corresponding to each laser tracker and the corresponding cosine value.

10. The method according to any one of claims 1-9, characterized in that, The process of iteratively solving for the initial three-dimensional coordinates to determine the coordinates that minimize the weighted sum of squared residuals of the multiple laser trackers, in order to obtain the target three-dimensional coordinates of the target reflector, includes: The Levenberg-Marquardt algorithm is used to iteratively solve the problem based on the initial three-dimensional coordinates to determine the coordinates that minimize the weighted sum of squared residuals of the multiple laser trackers, thereby obtaining the target three-dimensional coordinates of the target reflector.

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