Rocket drift distance measurement method, system and device based on laser radar point cloud cylinder fitting and storage medium
By using a multi-beam lidar point cloud cylindrical fitting algorithm, the rocket drift amount can be directly calculated, solving the problems of high cost and weak real-time performance in traditional methods, and realizing real-time and accurate measurement of rocket drift amount.
Patent Information
- Application Number
- CN202511690871.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-02-17
AI Technical Summary
Traditional methods for measuring rocket drift rely on multiple optoelectronic devices, which are costly and cannot be measured in real time. Early lidar systems had limited wiring, making the measurement process cumbersome and computationally intensive, thus reducing the real-time performance and efficiency of the measurement.
Point cloud data is acquired using a multi-beam lidar, and the rocket drift is measured in real time using a cylindrical fitting algorithm. This simplifies the ellipse fitting and data correction steps, and the rocket drift is directly calculated using the high-resolution point cloud data provided by the multi-beam lidar.
It enables real-time and accurate measurement of rocket drift, reduces measurement costs, improves the real-time performance and accuracy of measurements, and provides immediate and reliable decision-making support.
Smart Images
Figure CN121541172A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aerospace measurement, specifically to a method, system, device, and storage medium for measuring rocket drift by cylindrical fitting of lidar point clouds. Background Technology
[0002] Rocket drift measurement has significant applications in the aerospace field. Traditional methods for measuring rocket drift typically rely on cross-sectional measurements using multiple optoelectronic devices, resulting in complex equipment configurations, high costs, and post-launch data processing, making real-time measurement impossible. With advancements in rocket technology, accurately and in real-time measuring of rocket drift during launch has become a pressing technical challenge.
[0003] In recent years, LiDAR-based methods for measuring rocket drift have gradually emerged. LiDAR technology offers high resolution and enables real-time single-station measurements. Compared to traditional optoelectronic equipment, LiDAR not only reduces measurement costs but also significantly improves real-time performance and efficiency. However, early LiDAR systems had extremely limited line counts (e.g., 4 lines). While they could provide some point cloud data, they required complex ellipse fitting methods to extract rocket trajectory offsets, resulting in a cumbersome measurement process and high computational load, thus reducing the real-time performance of the measurements. Summary of the Invention
[0004] To address the problems mentioned in the prior art, this invention proposes a method, system, device, and storage medium for measuring rocket drift by cylindrical fitting of lidar point clouds. Utilizing high-resolution point cloud data provided by a multi-beam lidar, the invention achieves real-time measurement of rocket drift through a cylindrical fitting algorithm. This eliminates the need for complex elliptical fitting and data correction steps, solving the problems of complex calculation processes and weak real-time measurement in the prior art, and improving the real-time performance and accuracy of the measurement.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention discloses a method for measuring rocket drift by cylindrical fitting of lidar point clouds, comprising the following steps: S1. Obtain the point cloud data of the section of the rocket body between the two marked rings when the rocket is stationary as the static point cloud to be fitted, Ps. S2. Perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; S3. After the rocket takes off, the point cloud data of the cylinder segment between two marked rings in a certain frame of dynamic point cloud is obtained as the dynamic point cloud to be fitted, Pd. S4. Perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. S5. Using the axis of the static cylinder in S2 as a reference, calculate the vertical distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder as the first distance, and calculate the vertical distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder as the second distance. Based on the first and second distances, determine the drift of the rocket at the two marking rings.
[0006] As a further improvement of the present invention, the cylindrical fitting of the static point cloud Ps to be fitted in step S2, and the extraction of parameters of the static cylinder, includes: The center point of the point cloud is calculated, and the initial axis direction vector is extracted based on the three-dimensional principal component analysis method. Using the center point and the initial axis direction vector as initial values, the least squares nonlinear optimization algorithm is used to iterate until the fitting error function converges, thereby obtaining the optimized parameter set. The parameters of the static cylinder are then obtained by fitting the parameter set.
[0007] As a further improvement to the present invention, the expression of the error function is as follows:
[0008] In the formula: Represents the first point in the static point cloud Ps to be fitted. i The three-dimensional coordinates of each point; This represents the average coordinates of all points in the static point cloud Ps to be fitted, in three directions. This represents the extracted axis direction vector; The radius is the radius of the static cylinder to be fitted. As a further improvement to the present invention, the unit direction vector of the central axis in S2 cylinder diameter Center of the bottom circle Center of the apex and height The expression is as follows: .
[0009] As a further improvement of the present invention, in step S5, the vertical distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder is calculated as the first distance, and the vertical distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder is calculated as the second distance, which is obtained by the following formula:
[0010]
[0011] In the formula: This is the first distance; The unit direction vector of the axis of the static cylinder; The coordinates of the center of the base circle of the dynamic cylinder; Let be the coordinates of the center of the base circle of the static cylinder; This is the second distance; The coordinates of the center of the top circle of the dynamic cylinder; These are the coordinates of the center of the top circle of the static cylinder.
[0012] As a further improvement of the present invention, the acquisition of point cloud data of the cylindrical segment between the two marking rings in S1 and S3 includes: segmenting the point cloud data between the two marking rings by identifying the sparse area of the point cloud caused by the low reflectivity of the marking rings.
[0013] As a further improvement of the present invention, point cloud data of the rocket in static and dynamic states are acquired by a multi-beam lidar in S1 and S3 respectively; the number of beams of the multi-beam lidar is not less than 400.
[0014] This invention proposes a rocket drift measurement system based on cylindrical fitting of lidar point clouds, comprising: The radar module is used to acquire point cloud data of the section of the rocket body between two marked rings when the rocket is stationary, as the static point cloud Ps to be fitted. The processing module is used to perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; The radar module is used to acquire point cloud data of the cylindrical section between two marked rings in a certain frame of dynamic point cloud after rocket launch, as the dynamic point cloud Pd to be fitted. The processing module is used to perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and to extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. Determining Module: Based on the axis of the static cylinder, it calculates the first distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder, and the second distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder. Based on the first and second distances, it determines the drift of the rocket at the two marked rings.
[0015] This invention proposes a rocket drift measurement device based on cylindrical fitting of lidar point clouds, comprising a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rocket drift measurement method based on cylindrical fitting of lidar point clouds as described above.
[0016] This invention proposes a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the rocket drift measurement method for cylindrical fitting of lidar point clouds as described above.
[0017] Compared with the prior art, the present invention achieves the following technical effects: This invention utilizes a multi-beam lidar to acquire point cloud data of rocket tube sections and replaces traditional methods such as intersection measurement with multiple photoelectric devices or complex ellipse fitting with cylindrical fitting, thereby simplifying the calculation process and significantly reducing costs and complexity. This invention extracts the cylindrical geometric parameters of the rocket's marking rings in a static state as a benchmark and compares them with the spatial geometric relationship of the cylinder center fitted by the dynamic point cloud after takeoff, directly calculating the drift amount. This achieves processing from data acquisition to result output, ensuring the real-time monitoring of rocket drift during the initial takeoff stage, thus providing immediate and reliable decision-making support and demonstrating strong practicality. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the overall process of the present invention; Figure 2 This is a schematic diagram of the rocket marking ring in this invention; Figure 3 This is a schematic diagram of the static cylinder after cylinder fitting according to the present invention; Figure 4 This is a schematic diagram of the marking ring of the present invention after rocket launch; Figure 5 This is a schematic diagram of the dynamic cylinder after cylinder fitting according to the present invention; Figure 6 This is a schematic diagram illustrating the drift calculation and actual fitting of the present invention. Detailed Implementation
[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0020] This embodiment proposes a method for measuring rocket drift by cylindrical fitting of lidar point clouds, including the following steps: S1. Obtain the point cloud data of the section of the rocket body between the two marked rings when the rocket is stationary as the static point cloud to be fitted, Ps. S2. Perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; S3. After the rocket takes off, the point cloud data of the cylinder segment between two marked rings in a certain frame of dynamic point cloud is obtained as the dynamic point cloud to be fitted, Pd. S4. Perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. S5. Using the axis of the static cylinder in S2 as a reference, calculate the vertical distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder as the first distance, and calculate the vertical distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder as the second distance. Based on the first and second distances, determine the drift of the rocket at the two marking rings.
[0021] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments: Step 1: The preferred lidar used in this embodiment includes, but is not limited to, multi-beam (e.g., 400-beam) time-of-flight (TOF) lidar and frequency-modulated continuous wave (FMCW) lidar. Its field of view should at least cover the entire initial launch height of the rocket after it leaves the launch tower, and its scanning resolution should be at least better than 0.5m@200m. In this embodiment, the measurement object is a rocket target with at least two marked rings. Since the rocket is mostly white with high reflectivity, while the marked rings are generally black with low reflectivity and high light absorption, the lidar has very weak black echo signals, resulting in very few image point clouds for the two marked rings. Therefore, the point cloud of the rocket measured by the lidar can most likely be segmented into a cylindrical segment point cloud between the two marked rings.
[0022] like Figure 2 As shown, Figure 2 In the study, the point cloud on the rocket surface obtained by lidar measurement contained a total of 1793 points, and the number of point clouds between the two marked rings was 397.
[0023] In addition, the known rocket design dimensions can be used to extract the point cloud between the part of the rocket standing vertically and the two marked rings at the same height, which can be used as the cylindrical point cloud between the two marked rings. The appropriate measurement method can be selected according to different application scenarios.
[0024] When the rocket is stationary, the point cloud data between two marked rings obtained by imaging with lidar is called the static point cloud Ps of the rocket.
[0025] Step 2: For the point cloud data Ps between the two marked rings obtained in Step 1 Perform cylindrical fitting, where i is the number of point clouds, as follows: First, calculating the point cloud Ps requires an initial set of values for cylindrical fitting. Including the computing point cloud center ( ), the direction vector of the three-dimensional axis passing through the center Cylinder height Cylinder radius ,in: (1) Three-dimensional axis direction vector passing through the center Three-dimensional principal component analysis (PCA) is applied directly to the point cloud Ps. The coordinates are obtained from the above, with each axis represented by a 1×3 direction vector; due to the measurement coordinate system The axis is along the rocket's altitude, therefore the cylinder height... It is along - Direction by The maximum value is obtained by subtracting the minimum value from the maximum value.
[0026] Therefore, the cylinder radius The formula for calculation is: (2) In the above formula Represent each point To the initial center point Euclidean distance; for The average value.
[0027] Equation (2) represents the point set Ps Relative center point in space The distribution width, i.e., the center point The range of variation in distance between the points and other points is used here as the initial value for the fitted radius of the cylindrical segment.
[0028] The final initial value set For a 1×8 row matrix: (3) Design a cylinder fitting error optimization function and import Ps. Point set, relative to initial value set The parameters are subjected to least-squares nonlinear optimization iteration. The error optimization function is designed as follows: (4) In the formula: Represents the first point in the static point cloud Ps to be fitted. i The three-dimensional coordinates of each point; This represents the average coordinates of all points in the static point cloud Ps to be fitted, in three directions. This represents the extracted axis direction vector; The radius is the radius of the static cylinder to be fitted.
[0029] Equation (4) represents each point Ps With the center The projection of the subtracted vector onto the x-axis is then subtracted from the initial radius value. Theoretically, the optimal result is considered to be achieved when the extreme value of the function reaches 0; however, due to the unsatisfactory nature of data in practice, a convergence threshold of 1e-6 is set. When the value of the function is below the threshold, the function converges, and the set of parameters for iterative optimization is obtained. Its expression is: (5) Finally, based on the optimized parameter set Calculate the five key parameters of the fitted cylinder, namely the unit direction vector of the axis. cylinder diameter Center of the bottom circle Center of the apex ,high : (6) like Figure 3 The diagram shown is a schematic of the static cylinder obtained after cylindrical fitting of the static point cloud Ps according to the above steps.
[0030] See Table 1, which is a table of key parameters for fitting a static cylinder to a static point cloud Ps.
[0031] Table 1. Five key parameters for fitting a cylinder from a stationary point cloud.
[0032] Step 3: After the rocket takes off, the point cloud data between two marked rings in a frame of dynamic point cloud captured by the lidar is extracted and used as the dynamic point cloud Pd to be fitted. Referring to the description in step one, the moment of rocket ignition is recorded as t=0s. From the time the rocket takes off until its tail has left the launch tower range, t<10s. During this process, the quality of the lidar point cloud collected is relatively good. The point cloud data between the two marked rings can be selected from the dynamic flight point cloud frame as the dynamic point cloud to be fitted, Pd. like Figure 4 As shown, Figure 4 The middle frame is a point cloud frame collected at t=2.6s after rocket launch. The rocket has 1835 point clouds, and the dynamic point cloud Pd between the two marked rings has 406 points, which is close to the 397 points captured when the rocket was at rest.
[0033] Step 4: Perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and obtain the following 5 parameters: axis direction vector, cylinder diameter, bottom circle center, top circle center, and height. The process in this step is basically the same as in step two. The dynamic point cloud Pd to be fitted is subjected to cylindrical fitting using the process in step two, resulting in the unit direction vector of the axis of the dynamic cylinder. cylinder diameter Center of the bottom circle Center of the apex ,high : (7) like Figure 5 The diagram shown is a schematic of the dynamic cylinder obtained by performing cylindrical fitting on the dynamic point cloud Pd 2.6s after rocket launch according to the above steps.
[0034] See Table 2, which shows the key parameters for fitting a dynamic cylinder to the dynamic point cloud Pd. Table 2. Five key parameters for fitting the cylinder from the point cloud at 2.6 seconds after takeoff.
[0035] Step 5: Using the parameters of the static and dynamic cylinders from Steps 2 and 4, calculate the drift of the rocket in a certain frame after takeoff.
[0036] Given that the unit direction vector of the axis of the static cylinder is at rest, Given a point on the line The center of the base circle of the dynamic cylinder Center of the apex The distances to this axis are as follows: (8) (9) In the formula: This is the first distance; The unit direction vector of the axis of the static cylinder; Let be the center vector of the base circle of the dynamic cylinder; Let be the center vector of the base circle of the static cylinder; This is the second distance; Let be the center vector of the top circle of the dynamic cylinder; Let be the center vector of the top circle of the static cylinder.
[0037] Therefore, as Figure 6 As shown, this embodiment calculates the drift of the center of the first marker ring of the rocket (i.e., the center of the top of the cylinder) at 2.6 seconds after liftoff based on the static and dynamic cylinder parameters obtained in Tables 1 and 2. The drift is 0.053m, which is the drift of the center of the second marked ring (i.e., the center of the bottom of the cylinder). The result was 0.047m, and the optical equipment measurement showed a high degree of agreement, proving the accuracy and reliability of the invention.
[0038] Based on the same inventive concept, this invention also provides a rocket drift measurement system based on cylindrical fitting of lidar point clouds. Since the principle of this rocket drift measurement system based on cylindrical fitting of lidar point clouds is similar to that of the aforementioned rocket drift measurement method based on cylindrical fitting of lidar point clouds, the implementation of this rocket drift measurement system based on cylindrical fitting of lidar point clouds can refer to the implementation of the rocket drift measurement method based on cylindrical fitting of lidar point clouds, and the repeated parts will not be described again.
[0039] In specific implementation, the rocket drift measurement system based on cylindrical fitting of lidar point clouds provided in this embodiment of the invention specifically includes: The radar module is used to acquire point cloud data of the section of the rocket body between two marked rings when the rocket is stationary, as the static point cloud Ps to be fitted. The processing module is used to perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; The radar module is used to acquire point cloud data of the cylindrical section between two marked rings in a certain frame of dynamic point cloud after rocket launch, as the dynamic point cloud Pd to be fitted. The processing module is used to perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and to extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. Determining Module: Based on the axis of the static cylinder, it calculates the first distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder, and the second distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder. Based on the first and second distances, it determines the drift of the rocket at the two marked rings.
[0040] Accordingly, this embodiment of the invention also provides a rocket drift measurement device based on cylindrical fitting of lidar point clouds, including a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rocket drift measurement method based on cylindrical fitting of lidar point clouds as provided in this embodiment of the invention.
[0041] For more detailed information on the above methods, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.
[0042] Accordingly, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the rocket drift measurement method for cylindrical fitting of lidar point clouds as described in the embodiments of the present invention.
[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems, devices, and storage media disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.
[0044] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0045] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.
[0046] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0047] The above provides a detailed description of the rocket drift measurement method, system, equipment, and storage medium for cylindrical fitting of lidar point clouds provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.
Claims
1. A method for measuring rocket drift by cylindrical fitting of lidar point clouds, characterized in that, Includes the following steps: S1. Obtain the point cloud data of the section of the rocket body between the two marked rings when the rocket is stationary as the static point cloud to be fitted, Ps. S2. Perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; S3. After the rocket takes off, the point cloud data of the cylinder segment between two marked rings in a certain frame of dynamic point cloud is obtained as the dynamic point cloud to be fitted, Pd. S4. Perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. S5. Using the axis of the static cylinder in S2 as a reference, calculate the vertical distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder as the first distance, and calculate the vertical distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder as the second distance. Based on the first and second distances, determine the drift of the rocket at the two marking rings.
2. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 1, characterized in that, In step S2, cylindrical fitting is performed on the static point cloud Ps to be fitted, and the parameters of the static cylinder are extracted, including: The center point of the point cloud is calculated, and the initial axis direction vector is extracted based on the three-dimensional principal component analysis method. Using the center point and the initial axis direction vector as initial values, the least squares nonlinear optimization algorithm is used to iterate until the fitting error function converges, thereby obtaining the optimized parameter set. The parameters of the static cylinder are then obtained by fitting the parameter set.
3. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 2, characterized in that, The expression for the error function is as follows: In the formula: Represents the first point in the static point cloud Ps to be fitted. i The three-dimensional coordinates of each point; This represents the average coordinates of all points in the static point cloud Ps to be fitted, in three directions. This represents the extracted axis direction vector; The radius is the radius of the static cylinder to be fitted.
4. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 2, characterized in that, The unit direction vector of the central axis of S2 cylinder diameter Center of the bottom circle Center of the apex and height The expression is as follows: 。 5. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 1, characterized in that, In step S5, the first distance is calculated as the vertical distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder, and the second distance is calculated as the vertical distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder, using the following formula: In the formula: This is the first distance; The unit direction vector of the axis of the static cylinder; The coordinates of the center of the base circle of the dynamic cylinder; Let be the coordinates of the center of the base circle of the static cylinder; This is the second distance; The coordinates of the center of the top circle of the dynamic cylinder; These are the coordinates of the center of the top circle of the static cylinder.
6. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 1, characterized in that, The acquisition of point cloud data of the cylindrical section between the two marker rings in S1 and S3 includes: segmenting the point cloud data between the two marker rings by identifying the sparse area of the point cloud caused by the low reflectivity of the marker rings.
7. The method for measuring rocket drift by cylindrical fitting of lidar point cloud according to claim 1, characterized in that, In S1 and S3, point cloud data of the rocket in static and dynamic states are acquired by a multi-beam lidar, respectively; the number of beams of the multi-beam lidar is not less than 400.
8. A rocket drift measurement system based on cylindrical fitting of lidar point clouds, characterized in that, include: The radar module is used to acquire point cloud data of the section of the rocket body between two marked rings when the rocket is stationary, as the static point cloud Ps to be fitted. The processing module is used to perform cylindrical fitting on the static point cloud Ps to be fitted, and extract the parameters of the static cylinder; the parameters include the unit direction vector of the axis, the cylinder diameter, the center of the bottom circle, the center of the top circle, and the height; The radar module is used to acquire point cloud data of the cylindrical section between two marked rings in a certain frame of dynamic point cloud after rocket launch, as the dynamic point cloud Pd to be fitted. The processing module is used to perform cylindrical fitting on the dynamic point cloud Pd to be fitted, and to extract the center of the bottom circle and the center of the top circle of the dynamic cylinder. Determining Module: Based on the axis of the static cylinder, it calculates the first distance from the center of the bottom circle of the dynamic cylinder to the axis of the static cylinder, and the second distance from the center of the top circle of the dynamic cylinder to the axis of the static cylinder. Based on the first and second distances, it determines the drift of the rocket at the two marked rings.
9. A device for measuring rocket drift by cylindrical fitting of lidar point cloud, characterized in that, It includes a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rocket drift measurement method by cylindrical fitting of lidar point cloud as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, Used to store a computer program, wherein the computer program, when executed by a processor, implements the rocket drift measurement method for cylindrical fitting of lidar point clouds as described in any one of claims 1 to 7.