A navigation trial method and system
Patent Information
- Application Number
- CN202610595741.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-30
- Publication Date
- 2026-07-24
Smart Images
Figure CN122453909A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of navigation and general aviation testing, and specifically to a navigation and general aviation testing method and system. Background Technology
[0002] With the increase in waterway traffic volume and the trend towards larger vessels, existing locks in waterways have become bottlenecks restricting the development of high-grade waterways, resulting in severe vessel congestion. To address the current problems of navigation obstruction and congestion at waterway hubs, eliminate safety hazards, and proactively adapt to the development requirements of major waterway transportation, the construction of new navigation structures is urgently needed. Ship model navigation tests are crucial for evaluating waterway navigation conditions, verifying the design rationality of hydraulic structures, and ensuring safe navigation for vessels. Traditional ship model testing methods rely primarily on manual observation or single-point measurements, which suffer from poor time synchronization accuracy of various sensor data. This leads to inaccurate correlation between the trajectory and control parameters, making it impossible to obtain precise ship attitude data when the model navigates within the waterway, thus failing to meet the requirements of navigation tests under complex flow fields. Summary of the Invention
[0003] To address the aforementioned shortcomings of existing technologies, this invention provides a navigation and navigation test method and system that achieves high-precision synchronization of visual data and rudder angle data during the navigation of a ship model, thereby enhancing the automation level of the test process.
[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A navigation and navigation test method is provided, which includes the following steps: S1: Use a camera and rudder angle signal acquisition device to collect navigation images and rudder angle data of the model aircraft sailing in the test section of the hydraulic model, and use the pinhole model of the camera to perform global calibration of the camera to obtain the camera calibration model. S2: Establish a time mapping relationship model between the time of acquiring navigation images and the sampling point time of acquiring rudder angle data, and use time synchronization calibration samples to fit the time mapping relationship model to obtain the fitted time mapping relationship model. S3: Based on the timestamp of the acquired navigation images, a synchronized timestamp is assigned to the rudder angle data according to the fitted time mapping relationship model, and time-synchronized navigation images and rudder angle data are obtained by linear interpolation. S4: Preprocess the time-synchronized navigation images to obtain grayscale navigation images, and filter the pixels located on both sides of the boundary based on the difference in grayscale values of the pixels in the grayscale navigation images to obtain the boundary points of the ship model. Use the boundary points as feature points to obtain the coordinates of the feature points in the continuously acquired navigation images in the pixel coordinate system. S5: Based on the camera calibration model, the coordinates of feature points in the pixel coordinate system are converted into three-dimensional coordinates in the world coordinate system, and the rotation matrix between consecutive time stamps is solved to calculate the heading angle, roll angle and pitch angle of the ship model at different time stamps. S6: Calculate the drift angle of the ship model based on the heading angle, and plot the time-drift angle / rudder angle relationship curve of the ship model during the test segment to evaluate the navigation safety of the test segment.
[0005] Further, step S1 includes: S11: Evenly distributed above the test section of the hydraulic model. N A camera is installed on the model aircraft to capture images of the aircraft's navigation during the test segment. A rudder angle signal acquisition device is also installed on the model aircraft to collect rudder angle data during the model aircraft's navigation during the test segment. S12: Establish the world coordinate system, camera coordinate system, and pixel coordinate system of the navigation image. Use the pinhole model of the camera to perform global calibration of the camera and obtain the camera calibration model.
[0006] Further, step S2 includes: S21: Establish the time for the camera to acquire navigation images Sampling time of rudder angle data acquisition by rudder angle signal acquisition device A time mapping relationship model between them; ; in, k Numbering the video frames of the navigation images. m Number the sampling points for the rudder angle data. a This is a time scaling factor. b This is the time offset. This is the synchronization error; S22: Send commands to the camera and rudder angle signal acquisition unit respectively to simultaneously acquire navigation images and rudder angle data, and obtain the timestamps of the simultaneous acquisition of navigation images and rudder angle data. , ,get I One time-synchronized calibration sample; S23: The objective function for constructing a fitting time mapping relationship model is to minimize the sum of squared timestamp errors of synchronous acquisition. S24: Employing the least squares method and based on the objective function, utilizing... I The time-synchronized calibration samples were fitted to the time mapping relationship model to solve for the time scaling coefficient. a and time offset b The fitted time mapping relationship model is obtained.
[0007] Further, step S3 includes: S31: Start the model ship and sail within the test section, with the camera operating at [frame rate]. The system continuously acquires navigation images of the ship model, with the rudder angle signal acquisition device sampling at a frequency of... Collect rudder angle data at frame rate Timestamps of navigation images acquired under certain conditions Based on the fitted time mapping model, synchronized timestamps are assigned to the rudder angle data. k For timestamp numbering; S32: Based on sampling frequency Timestamp of rudder angle data collection For timestamps Linear interpolation of the rudder angle data yields a time-synchronized navigation image. Rudder angle data .
[0008] Further, step S4 includes: S41: Timestamp The acquired navigation images are preprocessed to obtain grayscale navigation images, and a threshold for the difference in grayscale values of pixels on both sides of the ship model's boundary is set. Extract the grayscale value of each pixel in a grayscale navigation image. , j The pixel number in the grayscale navigation image. Let be the pixel coordinates in the grayscale navigation image; S42: Calculate any two pixels in a grayscale navigation image j , v The difference between gray values ,like And satisfy the distance between two pixels Then determine the pixel j , v Located on both sides of the boundary of the ship model; otherwise, determine the pixel. j , v Not located on either side of the boundary of the ship model; S43: Pixels located on both sides of the ship model's boundary j , v The midpoint between the points is used as the boundary point of the ship model to obtain all the boundary points in the grayscale navigation image, and these boundary points are used as feature points; continuous timestamps are obtained. Coordinates of feature points in the acquired navigation images in the pixel coordinate system , n Number the feature points.
[0009] Further, step S5 includes: S51: Based on the camera calibration model, the coordinates of feature points in each flight image are... Convert to 3D coordinates in world coordinate system ; S52: Solve the rotation matrix of the ship model between consecutive time stamps using the singular value decomposition method. Translation vector ; S53: Based on rotation matrix Calculate the ship model at different timestamps heading angle yaw angle Pitch angle .
[0010] Further, step S6 includes: S61: Based on the three-dimensional coordinates of the centroid in the world coordinate system Extract the horizontal and lateral coordinates of the ship model in the world coordinate system. Horizontal and vertical coordinates Calculate the trajectory angle of the ship model ; ; in, Each is a timestamp The horizontal and vertical coordinates of the ship model in the world coordinate system; S62: Utilizing track angle and heading angle Calculate the ship model at the timestamp drift angle , Using different timestamps drift angle Rudder angle data Plot the time-drift angle / rudder angle relationship curves of the ship model during the test voyage to assess the navigation safety of the test voyage.
[0011] A navigation test system is provided for performing the aforementioned navigation test method, comprising [missing information - likely referring to a system with components] uniformly arranged above the test section of a hydraulic model. N A camera, a model aircraft, a rudder angle signal acquisition device mounted on the model aircraft, and a remote control for the model aircraft; N The camera is connected to the computer via a multi-channel video acquisition unit, the rudder angle signal acquisition unit communicates with the computer via a wireless module, and the remote controller communicates with the model aircraft via a wireless module to remotely control the model aircraft. The computer is equipped with a data analysis and processing module, which is used to analyze and process navigation images and rudder angle data to obtain drift angle and rudder angle data, and to plot the time-drift angle / rudder angle relationship curve of the ship model during the test voyage.
[0012] The beneficial effects of this invention are as follows: This invention establishes a time mapping relationship between the camera and the rudder angle signal acquisition device through a linear regression model, controlling the time synchronization error between navigation image data and rudder angle data acquisition, ensuring precise time correspondence between the data; by utilizing image processing technology combined with attitude estimation methods to calculate the model's navigation attitude data, high-precision navigation attitude data can be obtained, providing effective data support for subsequent navigation safety analysis. The entire experimental process, from data acquisition and processing to result analysis, is fully automated, greatly improving experimental efficiency. The experimental method and system provided by this invention are applicable to various types of hydraulic models and ship models, and can be used for navigation safety testing and research in various projects such as inland waterways, ports, and water conservancy projects. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the navigation and navigation test.
[0014] Figure 2 For traffic Q Schematic diagram of the upstream navigation track of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 2055m³ / s; Figure 3 For traffic Q =2055m³ / s condition, the relationship curve of rudder angle / drift angle of a 1000t self-propelled cargo ship going uphill in the upstream section of the lock; Figure 4 For traffic Q Schematic diagram of the downstream trajectory of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 2055m³ / s; Figure 5 For traffic Q =2055m³ / s condition, rudder angle / drift angle relationship curve of a 1000t self-propelled cargo ship going downstream of the lock in the upstream section; Figure 6 For traffic Q Schematic diagram of the upstream trajectory of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 13000m³ / s; Figure 7 For traffic Q =13000m³ / s condition, the rudder angle / drift angle relationship curve of a 1000t self-propelled cargo ship going upstream of the lock; Figure 8 For traffic Q Schematic diagram of the downstream trajectory of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 13000m³ / s; Figure 9 For traffic Q =13000m³ / s condition, the rudder angle / drift angle relationship curve of a 1000t self-propelled cargo ship going downstream in the upstream section of the lock.
[0015] Figure 10 For traffic Q Schematic diagram of the upstream navigation track of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 20600m³ / s; Figure 11 For traffic Q =20600m³ / s condition, the rudder angle / drift angle relationship curve of a 1000t self-propelled cargo ship going uphill in the upstream section of the lock.
[0016] Figure 12 For traffic Q Schematic diagram of the downstream trajectory of a 1000t self-propelled cargo ship in the upstream section of the lock under the condition of 20600m³ / s; Figure 13 For traffic Q =20600m³ / s condition, rudder angle / drift angle relationship curve of a 1000t self-propelled cargo ship going downstream in the upstream section of the lock. Detailed Implementation
[0017] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.
[0018] A navigation and navigation test method includes the following steps: S1: Use a camera and rudder angle signal acquisition device to collect navigation images and rudder angle data of the model aircraft navigating within the test section of the hydraulic model, and use the pinhole model of the camera to perform global calibration of the camera to obtain the camera calibration model.
[0019] Step S1 specifically includes the following steps: S11: Evenly distributed above the test section of the hydraulic model. N A camera is installed on the model aircraft to capture images of the aircraft's navigation during the test segment. A rudder angle signal acquisition device is also installed on the model aircraft to collect rudder angle data during the model aircraft's navigation during the test segment. S12: Establish the world coordinate system, camera coordinate system, and pixel coordinate system of the navigation image. Use the pinhole model of the camera to perform global calibration of the camera and obtain the camera calibration model. ; in, Let Z be the Z-axis coordinate of the feature point on the ship model in the camera coordinate system. These are the coordinates of the feature point in the pixel coordinate system. Let X be the equivalent focal length in the X and Y axes when the camera coordinate system is projected onto the pixel coordinate system. Let be the coordinates of the principal point of the camera's optical imaging in the pixel coordinate system. R Let be the rotation matrix from the world coordinate system to the camera coordinate system. t This represents the position of the world coordinate system origin in the camera coordinate system. These are the coordinates of the feature point in the world coordinate system. This is the intrinsic parameter matrix of the camera.
[0020] This invention uses a pinhole model to establish the geometric relationships of camera imaging, and obtains accurate intrinsic and extrinsic parameters through calibration, providing a foundation for subsequent 3D reconstruction of the ship model's position and attitude. Compared to the traditional Direct Linear Transform (DLT) method, the pinhole model takes into account camera distortion, resulting in higher measurement accuracy.
[0021] S2: Establish a time mapping relationship model between the time of acquiring navigation images and the sampling point time of acquiring rudder angle data, and use time synchronization calibration samples to fit the time mapping relationship model to obtain the fitted time mapping relationship model.
[0022] Step S2 specifically includes the following steps: S21: Establish the time for the camera to acquire navigation images Sampling time of rudder angle data acquisition by rudder angle signal acquisition device A time mapping relationship model between them; ; in, k Numbering the video frames of the navigation images. m Number the sampling points for the rudder angle data. a The time scaling factor (under ideal conditions) a =1), b This is the time offset. This is the synchronization error; S22: Send commands to the camera and rudder angle signal acquisition unit respectively to simultaneously acquire navigation images and rudder angle data, and obtain the timestamps of the simultaneous acquisition of navigation images and rudder angle data. , ,get I One time-synchronized calibration sample; S23: The objective function for constructing a fitting time mapping relationship model is to minimize the sum of squared timestamp errors from synchronous acquisition. ; S24: Employing the least squares method and based on the objective function, utilizing... I The time-synchronized calibration samples were fitted to the time mapping relationship model to solve for the time scaling coefficient. a and time offsetb The fitted time mapping relationship model is obtained; .
[0023] In the navigation test system of this invention, the camera acquiring navigation images and the rudder angle signal acquisition device acquiring rudder angle data are independent hardware systems. Inherent deviations exist in the clock frequency, trigger time, and transmission delay during data acquisition, resulting in a time misalignment between image data and rudder angle data. This invention employs a univariate linear regression model to decompose the time deviation into a linear proportional term and a fixed offset term, separating drift error from fixed delay. Furthermore, using the least squares principle, with the minimum sum of squared errors between the two sets of timestamps as the optimization objective, it globally fits the optimal time proportional coefficient. a and time offset b This reduces fitting errors caused by random jitter at single points and improves time synchronization accuracy. (Time scaling factor) a Used to correct clock drift and time offset of the acquisition device. b Used to compensate for hardware latency and reference deviation. Synchronization error. This represents random time synchronization error, which follows a normal distribution and represents random noise such as hardware jitter and sampling jitter.
[0024] S3: Based on the timestamp of the acquired navigation images, a synchronized timestamp is assigned to the rudder angle data according to the fitted time mapping relationship model, and time-synchronized navigation images and rudder angle data are obtained by using linear interpolation.
[0025] Step S3 specifically includes the following steps: S31: Start the model ship and sail within the test section, with the camera operating at [frame rate]. The system continuously acquires navigation images of the ship model, with the rudder angle signal acquisition device sampling at a frequency of... Collect rudder angle data at frame rate Timestamps of navigation images acquired under certain conditions Based on the fitted time mapping model, synchronized timestamps are assigned to the rudder angle data. k For timestamp numbering; S32: Based on sampling frequency Timestamp of rudder angle data collection For timestamps Linear interpolation of the rudder angle data yields a time-synchronized navigation image. Rudder angle data ; ; in, For timestamps Collected rudder angle data, For timestamps Collected rudder angle data.
[0026] Since the camera and rudder angle signal acquisition device have vastly different data sampling frequencies, this invention uses a linear interpolation method to achieve precise time matching between navigation images and rudder angle data with different sampling rates, ensuring that each video frame has corresponding rudder angle data.
[0027] S4: Preprocess the time-synchronized navigation images to obtain grayscale navigation images, and filter the pixels located on both sides of the boundary based on the difference in grayscale values of the pixels in the grayscale navigation images to obtain the boundary points of the ship model. Use the boundary points as feature points to obtain the coordinates of the feature points in the continuously acquired navigation images in the pixel coordinate system.
[0028] Step S4 specifically includes the following steps: S41: Timestamp The acquired navigation images are preprocessed to obtain grayscale navigation images, and a threshold for the difference in grayscale values of pixels on both sides of the ship model's boundary is set. Extract the grayscale value of each pixel in a grayscale navigation image. , j The pixel number in the grayscale navigation image. Let be the pixel coordinates in the grayscale navigation image; S42: Calculate any two pixels in a grayscale navigation image j , v The difference between gray values ,like And satisfy the distance between two pixels Then determine the pixel j , v Located on both sides of the boundary of the ship model; otherwise, determine the pixel. j , v Not located on either side of the boundary of the ship model; ; in, For pixels v prime coordinates, This is the width threshold of the ship model boundary; S43: Pixels located on both sides of the ship model's boundary j , v The midpoint between the points is used as the boundary point of the ship model to obtain all the boundary points in the grayscale navigation image, and these boundary points are used as feature points; continuous timestamps are obtained. Coordinates of feature points in the acquired navigation images in the pixel coordinate system , n Number the feature points.
[0029] S5: Based on the camera calibration model, the coordinates of feature points in the pixel coordinate system are converted into three-dimensional coordinates in the world coordinate system, and the rotation matrix between consecutive time stamps is solved to calculate the heading angle, roll angle and pitch angle of the ship model at different time stamps.
[0030] Step S5 specifically includes the following steps: S51: Based on the camera calibration model, the coordinates of feature points in each flight image are... Convert to 3D coordinates in world coordinate system ; S52: Solve the rotation matrix of the ship model between consecutive time stamps using the singular value decomposition method. Translation vector ; ; in, For timestamps In the acquired navigation images N The three-dimensional coordinates of the centroid of each feature point in the world coordinate system. For timestamps In the acquired navigation images N The three-dimensional coordinates of the centroid of each feature point in the world coordinate system. For timestamps The three-dimensional coordinates of feature points in the acquired navigation images in the world coordinate system. H For two adjacent timestamps timestamp Decentralize the cross-covariance matrix of the feature points on the feature points; These are the left singular matrix, the singular value diagonal matrix, and the right singular matrix after singular value decomposition of the matrix, respectively. S53: Based on rotation matrix Calculate the ship model at different timestamps heading angle yaw angle Pitch angle ; ; in, Let X be the projection component of the world coordinate system X-axis onto the ship model's hull coordinate system X-axis. Let Y be the projection component of the world coordinate system Y-axis onto the ship model's hull coordinate system X-axis. This represents the projection component of the Z-axis of the world coordinate system onto the longitudinal axis of the ship's hull. This represents the projection component of the Z-axis of the world coordinate system onto the transverse axis of the ship's hull. This represents the projection component of the Z-axis of the world coordinate system onto the vertical axis of the ship's hull.
[0031] Heading angle It represents the angle of deflection of the longitudinal center axis (pointing towards the bow) of the ship model relative to the X-axis of the world coordinate system of the test section in the horizontal plane, and directly represents the ship model's sailing orientation.
[0032] Roll angle It represents the angle between the left and right sides of the ship model around its own longitudinal central axis, and is a quantitative indicator of the ship's left and right tilt.
[0033] Pitch angle It represents the pitch angle of the ship model around its own horizontal axis, with the bow pointing upwards being positive and the bow pointing downwards being negative. It is used to characterize the vertical attitude change of the ship, which is caused by the undulation of water flow, waves, and disturbance of the bottom topography of the channel.
[0034] S6: Calculate the drift angle of the ship model based on the heading angle, and plot the time-drift angle / rudder angle relationship curve of the ship model during the test segment to evaluate the navigation safety of the test segment.
[0035] Step S6 specifically includes the following steps: S61: Based on the three-dimensional coordinates of the centroid in the world coordinate system Extract the horizontal and lateral coordinates of the ship model in the world coordinate system. Horizontal and vertical coordinates Calculate the trajectory angle of the ship model ; ; in, Each is a timestamp The horizontal and vertical coordinates of the ship model in the world coordinate system; S62: Utilizing track angle and heading angle Calculate the ship model at the timestamp drift angle , Using different timestamps drift angle Rudder angle data Plot the time-drift angle / rudder angle relationship curves of the ship model during the test voyage to assess the navigation safety of the test voyage.
[0036] like Figure 1 As shown, a navigation test system is used to perform the navigation test method described in steps S1-S16 above, including [missing information - likely referring to a system with components] evenly arranged above the test section of the hydraulic model. N A camera, a model aircraft, a rudder angle signal acquisition device mounted on the model aircraft, and a remote control for the model aircraft; NThe camera is connected to the computer via a multi-channel video acquisition unit, the rudder angle signal acquisition unit communicates with the computer via a wireless module, and the remote controller communicates with the model aircraft via a wireless module to remotely control the model aircraft. The computer is equipped with a data analysis and processing module, which is used to analyze and process navigation images and rudder angle data to obtain drift angle and rudder angle data, and to plot the time-drift angle / rudder angle relationship curve of the ship model during the test voyage.
[0037] This embodiment takes a hydraulic model of a certain waterway as an example. By setting different operating conditions under different flow rates, and using the above-mentioned navigation test method, the drift angle of the ship model under different operating conditions is obtained. and rudder angle data Data such as...
[0038] This embodiment focuses on flow rate. Q =2055m³ / s (full flow, floodgates fully closed) Q =13000 m³ / s (common flood flow, controlled discharge during shutdown) and Q In the ship model test under three flow conditions, namely 20600m³ / s (maximum navigable flow, engine shutdown and open discharge), upstream and downstream tests were conducted on the upstream channel of a 1000t self-propelled ship model.
[0039] like Figure 2-13 As shown in Table 1 below, the data results of the ship model test are calculated based on the test data. Table 1. Data Table of Ship Model Test Results
[0040] It can be seen that the ships are in the flow Q =2055m³ / s Q =13000 m³ / s and Q When the speed is 20600 m³ / s, the average uphill bridge crossing distances are 1444 m, 1437 m, and 1455 m, respectively; the maximum rudder angles are 15.60°, 19.98°, and 21.53°, respectively; the maximum drift angles are 4.14°, 8.49°, and 15.04°, respectively; the minimum speeds are 4.42 m / s, 2.64 m / s, and 1.65 m / s, respectively; the sailing times are 5.22 minutes, 8.33 minutes, and 12.67 minutes, respectively; and the average speeds are 4.61 m / s, 2.87 m / s, and 1.91 m / s, respectively.
[0041] The maximum rudder angles for upstream passage over the bridge were 15.60°, 19.98°, and 21.53°, respectively, and the maximum drift angles were 4.14°, 8.49°, and 15.04°, respectively. All these angles increased with increasing flow rate, indicating that the difficulty of navigation increases with increasing flow rate. For upstream passage after exiting the lock, the maximum rudder angles were 15.60°, 19.98°, and 21.53°, all within the safe limit of rudder angle for model ship testing (25°). The minimum speeds were 4.42 m / s, 2.64 m / s, and 1.65 m / s, respectively, all better than the minimum safe speed limit for model ship testing (0.4 m / s).
[0042] Comparison of maximum rudder angle, drift angle, and speed for downstream bridge crossings under different traffic volumes. It can be seen that the average distance traveled downstream over the bridge was 1446m, 1426m, and 1446m, respectively; the maximum rudder angles were 17.83°, 20.65°, and 24.88°, respectively; the maximum drift angles were 3.26°, 12.15°, and 19.30°, respectively; the minimum speeds were 3.37m / s, 5.15m / s, and 5.39m / s, respectively; the travel times were 6.67 minutes, 4.33 minutes, and 4.11 minutes, respectively; and the average speeds were 3.61m / s, 5.48m / s, and 5.86m / s, respectively.
[0043] The data above shows that the maximum rudder angles for vessels passing under the bridge downstream were 17.83°, 20.65°, and 24.88°, and the maximum drift angles were 3.26°, 12.15°, and 19.30°, respectively. All these values increased with increasing flow rate, indicating that the difficulty of navigation increases with increasing flow rate. The flow rate during downstream bridge passage... Q =2055m³ / s Q In the model ship test under the condition of 13000 m³ / s, the ship exited the lock and sailed upstream, with maximum rudder angles of 17.83° and 20.65°, which did not exceed the safe limit for rudder angle in model ship tests (25°). At the flow rate... Q During the 20600m³ / s ship model test, the maximum rudder angle of the ship when it went downstream to pass the bridge reached 24.88°, which is close to the safe limit of rudder angle for ship model tests (25°). The ship was difficult to maneuver and required careful driving to ensure navigation safety.
[0044] Ship model tests show that the difficulty of navigation increases with increasing flow rate. The minimum speed of the ships is always better than the minimum safe speed limit of the ship model tests, indicating that speed is not the main factor affecting navigation. The angle at which ships navigate through bridges and locks increases, and the maximum rudder angle during high flow rates approaches the safe rudder angle limit of the ship model tests (25°). Caution is required to ensure the safe passage of ships through bridges.
[0045] In summary, the navigation flow rate upstream of the lock is Q ≤20600m³ / s, but navigation is difficult.
Claims
1. A navigation and navigation test method, characterized in that, Includes the following steps: S1: Use a camera and rudder angle signal acquisition device to collect navigation images and rudder angle data of the model aircraft sailing in the test section of the hydraulic model, and use the pinhole model of the camera to perform global calibration of the camera to obtain the camera calibration model. S2: Establish a time mapping relationship model between the time of acquiring navigation images and the sampling point time of acquiring rudder angle data, and use time synchronization calibration samples to fit the time mapping relationship model to obtain the fitted time mapping relationship model. S3: Based on the timestamp of the acquired navigation images, a synchronized timestamp is assigned to the rudder angle data according to the fitted time mapping relationship model, and time-synchronized navigation images and rudder angle data are obtained by linear interpolation. S4: Preprocess the time-synchronized navigation images to obtain grayscale navigation images, and filter the pixels located on both sides of the boundary based on the difference in grayscale values of the pixels in the grayscale navigation images to obtain the boundary points of the ship model. Use the boundary points as feature points to obtain the coordinates of the feature points in the continuously acquired navigation images in the pixel coordinate system. S5: Based on the camera calibration model, the coordinates of feature points in the pixel coordinate system are converted into three-dimensional coordinates in the world coordinate system, and the rotation matrix between consecutive time stamps is solved to calculate the heading angle, roll angle and pitch angle of the ship model at different time stamps. S6: Calculate the drift angle of the ship model based on the heading angle, and plot the time-drift angle / rudder angle relationship curve of the ship model during the test segment to evaluate the navigation safety of the test segment.
2. The navigation and navigability test method according to claim 1, characterized in that, Step S1 includes: S11: Evenly distributed above the test section of the hydraulic model. N A camera is installed on the model aircraft to capture images of the aircraft's navigation during the test segment. A rudder angle signal acquisition device is also installed on the model aircraft to collect rudder angle data during the model aircraft's navigation during the test segment. S12: Establish the world coordinate system, camera coordinate system, and pixel coordinate system of the navigation image. Use the pinhole model of the camera to perform global calibration of the camera and obtain the camera calibration model.
3. The navigation and navigation test method according to claim 2, characterized in that, Step S2 includes: S21: Establish the time for the camera to acquire navigation images Sampling time of rudder angle data acquisition by rudder angle signal acquisition device A time mapping relationship model between them; ； in, k Numbering the video frames of the navigation images. m Number the sampling points for the rudder angle data. a This is a time scaling factor. b This is the time offset. This is the synchronization error; S22: Send commands to the camera and rudder angle signal acquisition unit respectively to simultaneously acquire navigation images and rudder angle data, and obtain the timestamps of the simultaneous acquisition of navigation images and rudder angle data. , ,get I One time-synchronized calibration sample; S23: The objective function for constructing a fitting time mapping relationship model is to minimize the sum of squared timestamp errors of synchronous acquisition. S24: Employing the least squares method and based on the objective function, utilizing... I The time-synchronized calibration samples were fitted to the time mapping relationship model to solve for the time scaling coefficient. a and time offset b The fitted time mapping relationship model is obtained.
4. The navigation and navigability test method according to claim 3, characterized in that, Step S3 includes: S31: Start the model ship and sail within the test section, with the camera operating at [frame rate]. The system continuously acquires navigation images of the ship model, with the rudder angle signal acquisition device sampling at a frequency of... Collect rudder angle data at frame rate Timestamps of navigation images acquired under certain conditions Based on the fitted time mapping model, synchronized timestamps are assigned to the rudder angle data. k For timestamp numbering; S32: Based on sampling frequency Timestamp of rudder angle data collection For timestamps Linear interpolation of the rudder angle data yields a time-synchronized navigation image. Rudder angle data .
5. The navigation and navigability test method according to claim 4, characterized in that, Step S4 includes: S41: Timestamp The acquired navigation images are preprocessed to obtain grayscale navigation images, and a threshold for the difference in grayscale values of pixels on both sides of the ship model's boundary is set. Extract the grayscale value of each pixel in a grayscale navigation image. , j The pixel number in the grayscale navigation image. Let be the pixel coordinates in the grayscale navigation image; S42: Calculate any two pixels in a grayscale navigation image j , v The difference between gray values ,like And satisfy the distance between two pixels Then determine the pixel j , v Located on both sides of the boundary of the ship model; otherwise, determine the pixel. j , v Not located on either side of the boundary of the ship model; S43: Pixels located on both sides of the ship model's boundary j , v The midpoint between the points is used as the boundary point of the ship model to obtain all the boundary points in the grayscale navigation image, and these boundary points are used as feature points; continuous timestamps are obtained. Coordinates of feature points in the acquired navigation images in the pixel coordinate system , n Number the feature points.
6. The navigation and navigation test method according to claim 5, characterized in that, Step S5 includes: S51: Based on the camera calibration model, the coordinates of feature points in each flight image are... Convert to 3D coordinates in world coordinate system ; S52: Solve the rotation matrix of the ship model between consecutive time stamps using the singular value decomposition method. Translation vector ; S53: Based on rotation matrix Calculate the ship model at different timestamps heading angle yaw angle Pitch angle .
7. The navigation and navigability test method according to claim 6, characterized in that, Step S6 includes: S61: Based on the three-dimensional coordinates of the centroid in the world coordinate system Extract the horizontal and lateral coordinates of the ship model in the world coordinate system. Horizontal and vertical coordinates Calculate the trajectory angle of the ship model ; ； in, Each is a timestamp The horizontal and vertical coordinates of the ship model in the world coordinate system; S62: Utilizing track angle and heading angle Calculate the ship model at the timestamp drift angle , Using different timestamps drift angle Rudder angle data Plot the time-drift angle / rudder angle relationship curves of the ship model during the test voyage to assess the navigation safety of the test voyage.
8. A navigation test system for performing the navigation test method according to any one of claims 1-7, characterized in that, Including those evenly distributed above the test section of the hydraulic model N A camera, a model aircraft, a rudder angle signal acquisition device mounted on the model aircraft, and a remote control for the model aircraft; N The camera is connected to the computer via a multi-channel video acquisition unit, the rudder angle signal acquisition unit communicates with the computer via a wireless module, and the remote controller communicates with the model aircraft via a wireless module to remotely control the model aircraft. The computer is equipped with a data analysis and processing module, which is used to analyze and process navigation images and rudder angle data to obtain drift angle and rudder angle data, and to plot the time-drift angle / rudder angle relationship curve of the ship model during the test voyage.