An automatic scanning laser ranging system

Abstract

The application discloses an automatic scanning type laser ranging system, a laser range finder is arranged on a horizontal side of a moving target along a moving direction, and a distance value is measured in real time under the control of an automatic scanning control system; when the distance value measured by the laser range finder changes by more than a set threshold value, the automatic scanning control system controls the laser range finder to swing horizontally to reduce the angle of the laser range finder, the angle of the laser range finder is the included angle between the outgoing laser of the laser range finder and the moving direction; and an information processing system determines the moving speed and / or position of the moving target according to the time when the distance value changes by more than the set threshold value twice, the angle of the laser range finder and the horizontal distance between the moving target and the laser range finder, so that the speed and / or position of the moving target when moving in a ranging space can be determined with high precision, the scanning can be automatically started when the moving target is detected, the scanning can be stopped when there is no moving target, and the service life and reliability of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of ranging technology, and more specifically to an automatic scanning laser ranging system. Background Technology

[0002] Currently, the main solutions for detecting the speed / displacement of vehicles or ships include: infrared photoelectric switch (sensor) solution, laser ranging solution, continuous wave (LFMCW) speed and ranging radar solution, GPS (Global Positioning System) solution, image recognition technology solution, and radio frequency identification technology solution.

[0003] Infrared photoelectric switch (sensor) solutions have weak anti-interference capabilities, limited measurement distance, and cannot continuously and dynamically measure the speed and displacement of vehicles or ships throughout the entire measurement range.

[0004] There are no examples of laser ranging solutions being applied in special scenarios such as confined spaces, close proximity, and slow speeds in locks or ship lifts.

[0005] In continuous wave speed and distance measurement radar schemes, due to the straight-line propagation characteristic of radar waves and the different reflection intensities of radar waves caused by different ship sizes and shapes, the measurement results may have large deviations. In particular, the angle between the installation position of the speed measuring radar and the target can lead to large deviations in the target's position measurement results. In addition, the radar signal can be interfered with by surrounding radio waves, resulting in unstable speed measurement readings of the target vehicle (ship).

[0006] GPS positioning accuracy is limited by a variety of factors. Weather conditions in the ionosphere, as well as nearby buildings and ground conditions, can all cause signal delays. It is not a solution for direct close-range measurement of targets, which also limits the application of GPS speed measurement.

[0007] Image recognition technology solutions have high requirements for the invariance of the shape of the measured object and the scene, strict requirements for the measurement environment, are greatly affected by the ambient light, and the installation location of the camera is relatively limited. Image recognition technology for the boundary of the target object has certain difficulties in extracting distance information, and the position detection accuracy is not high. There are no examples of its application in special scenarios such as locks or ship lifts where the detection space is small, the shape of the ship is varied, and the background is complex.

[0008] The radio frequency identification (RFID) technology solution requires all vessels to install RFID electronic tags, which makes its widespread adoption difficult.

[0009] It is known that there are various technologies for detecting the speed (displacement) of vehicles or ships, each with its own technical performance characteristics. Each technology is highly targeted to specific application scenarios, but there are currently no mature engineering application examples of these technologies in locks or ship lifts, which brings great uncertainty to the actual application in engineering construction. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide an automatic scanning laser ranging system. This invention can accurately determine the speed and / or position of a moving target within the ranging space, automatically initiating scanning when a moving target is detected and stopping scanning when no moving target passes by, thereby improving system lifespan and reliability.

[0011] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0012] An automatic scanning laser ranging system includes: a laser rangefinder, an automatic scanning control system, and an information processing system;

[0013] The laser rangefinder is positioned on the horizontal side of the moving target along the direction of movement and measures the distance value in real time under the control of the automatic scanning control system.

[0014] When the distance value measured by the laser rangefinder changes beyond a set threshold, the automatic scanning control system controls the laser rangefinder to swing horizontally to reduce the angle of the laser rangefinder. The angle of the laser rangefinder is the angle between the laser emitted by the laser rangefinder and the direction of movement.

[0015] The information processing system determines the moving speed and / or position of the moving target based on the time when the two distance value changes exceed a set threshold, the angle of the laser rangefinder, and the horizontal distance between the moving target and the laser rangefinder.

[0016] The present invention provides an automatic scanning laser ranging system that can accurately determine the speed and / or position of a moving target in the ranging space. Furthermore, the automatic scanning control system can automatically start scanning when a moving target is detected and stop scanning when no moving target passes by, thereby improving the system's lifespan and reliability.

[0017] Based on the above technical solution, the present invention can also be improved as follows.

[0018] Optionally, the number of laser rangefinders is set according to the width of the ranging space in the horizontal direction and the angle range of the laser rangefinders. Each laser rangefinder is set at equal distances so that the moving target is within the monitoring range of at least one laser rangefinder. The horizontal direction is the direction perpendicular to the direction of movement on the horizontal plane.

[0019] Optionally, the maximum distance between each of the laser rangefinders is: D = 2L max ×tanθ max ; among which, L max Let θ be the width of the distance measurement space in the horizontal direction. max The angle between the laser rangefinder and the horizontal direction is the maximum angle between the laser rangefinder and the horizontal direction, which is the direction perpendicular to the direction of movement on the horizontal plane.

[0020] Optionally, laser rangefinders are respectively set at both ends of the ranging space. The moving direction of the moving target is determined according to the position of the laser rangefinder that first measures the distance value to be small, and the initial angle of each laser rangefinder is determined according to the moving direction.

[0021] Optionally, the moving target's moving speed is:

[0022]

[0023] L1 represents the horizontal distance between the moving target and the laser rangefinder. t1 and t2 are the times when the distance changes exceed the set threshold, respectively. θ1 and θ2 are the angles between the projection direction of the laser emitted by the laser rangefinder onto the horizontal plane and the horizontal direction when the distance changes exceed the set threshold, respectively.

[0024] Optionally, the horizontal distance between the central axis of the moving target and the laser rangefinder is L1 = L0 × cosθ0, where L0 is the distance measured by the laser rangefinder when the angle between the laser rangefinder and the horizontal direction is θ0.

[0025] Optionally, the information processing system further includes:

[0026] The real-time distance between the moving target and the destination is calculated as: S = N × lL × sinθ + x + Δs;

[0027] N represents the number of laser rangefinders remaining after the current laser rangefinder, l represents the distance between the laser rangefinders, θ represents the angle between the current laser rangefinder and the horizontal direction, L represents the distance measured by the current laser rangefinder, x represents the distance between the laser rangefinder at the endpoint and the endpoint, and Δs represents the system error.

[0028] Optionally, the height of the two laser rangefinders set at both ends of the ranging space is the same as the height of the moving target.

[0029] Optionally, the laser rangefinder that first measures the distance value to be small is identified as the first laser tester. The information processing system performs linear fitting on the trajectory of the moving target along the moving direction measured by the first laser tester. Based on the trajectory, the vertical distance L' between the moving target and the side of the ranging space where the laser rangefinder is located is determined. The pitch angle of the other laser rangefinders is adjusted as: α = arctanL' / d, where d is the installation height of the other laser rangefinders.

[0030] Compared with existing technologies, the automatic scanning laser ranging system mentioned in this invention has the following main advantages:

[0031] This invention provides an automatic scanning laser ranging system. It utilizes laser rangefinders for real-time distance measurement. When there is no moving target obstructing the path, all laser rangefinders measure the distance to the opposite side, and these distances at different angles are stored in a fixed array for reference. When a moving target obstructs the path, the laser rangefinders measure the distance to the moving target, and a significant difference exists between the two measurements. The moment the laser rangefinder detects this difference indicates the passing of a moving target. The current time and the angle of the laser rangefinder are recorded. Then, under the control of the automatic scanning control system, the system rotates a certain angle in the direction of the ship's movement. When the distance measured by this laser rangefinder again shows a significant difference compared to when there is no moving target, the time and the angle of the laser rangefinder are recorded again. Based on the rotation angle of the laser rangefinder and the horizontal distance between the moving target and the laser rangefinder, the distance traveled by the moving target during this period can be determined, further determining the speed and position of the moving target. The automatic scanning control system can automatically start scanning when a moving target is detected and stop scanning when no moving target passes, improving system lifespan and reliability. Attached Figure Description

[0032] Figure 1 A structural block diagram of an automatic scanning laser ranging system provided by the present invention;

[0033] Figure 2 This is a schematic diagram illustrating the working principle of the automatic scanning laser ranging system provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram illustrating the working principle of the laser rangefinder provided in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram illustrating the working principle of the laser rangefinder for automatic calibration provided in an embodiment of the present invention.

[0036] In the diagram, 101 is a laser rangefinder, 102 is an automatic scanning control system, 103 is an information processing system, and 104 is a mounting bracket. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present patent. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present patent.

[0038] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0039] like Figure 1 As shown, the ranging system includes a laser rangefinder 101, an automatic scanning control system 102, and an information processing system 103, used to measure the moving speed of a moving target.

[0040] The laser rangefinder is mounted on the horizontal side of the moving target along the direction of movement via a mounting bracket 104, and measures the distance value in real time under the control of the automatic scanning control system.

[0041] A laser rangefinder is an instrument that accurately measures the distance to a target by modulating a laser beam with a specific parameter. A pulsed laser rangefinder emits a single or a series of short pulsed laser beams towards the target. A photoelectric element receives the reflected laser beam, and a timer measures the time from emission to reception to calculate the distance from the rangefinder to the target. It features high speed, long range, high accuracy, and ease of installation and networking. An automatic scanning control system can control the laser rangefinder to perform small-angle scans along the ship's direction of travel.

[0042] When the distance measured by the laser rangefinder changes beyond a set threshold, the automatic scanning control system controls the laser rangefinder to swing horizontally to reduce the angle of the laser rangefinder. The angle of the laser rangefinder is the angle between the laser emitted by the laser rangefinder and the direction of movement.

[0043] The information processing system determines the moving speed of the target based on the time when the two distance values ​​change beyond a set threshold, the angle of the laser rangefinder, and the horizontal distance between the moving target and the laser rangefinder.

[0044] Example 1

[0045] Embodiment 1 provided by the present invention is an embodiment of an automatic scanning laser ranging system provided by the present invention. This embodiment of the laser ranging system is used to measure the real-time speed of a ship after it enters the cabin and the distance to the destination.

[0046] Examples of the ranging system include: a laser rangefinder, an automatic scanning control system, and an information processing system.

[0047] The laser rangefinder is positioned on the horizontal side of the moving target along the direction of movement and measures the distance in real time under the control of the automatic scanning control system.

[0048] Preferably, the number of laser rangefinders is set according to the horizontal width of the ranging space and the angular range of the laser rangefinders. The laser rangefinders are set at equal intervals so that the moving target is within the monitoring range of at least one laser rangefinder; the horizontal direction is the direction perpendicular to the direction of movement on the horizontal plane. For example... Figure 2 The diagram shown illustrates the working principle of the automatic scanning laser ranging system provided in an embodiment of the present invention. Figure 2 The given embodiment takes the exit of a ship traveling upstream from its cargo hold as an example. Figure 3 This is a schematic diagram illustrating the working principle of the laser rangefinder provided in this embodiment of the invention, showing the influence of different ship travel routes on the measurement results when the pitch angle is fixed.

[0049] The ranging space refers to the spatial range within which the moving target can move. In the embodiments provided by this invention, this is a lock or a ship lift cabin. When the ranging space is a lock cabin, the water level inside the lock cabin frequently changes. The height and pitch angle of the laser rangefinder are determined based on the current water level during calculation.

[0050] Furthermore, the maximum distance between each laser rangefinder is: D = 2L max ×tanθ max ; among which, L max Let θ be the width of the distance measurement space in the horizontal direction. max The angle between the laser rangefinder and the horizontal direction is the maximum angle between the laser rangefinder and the horizontal direction, which is the direction perpendicular to the direction of movement on the horizontal plane.

[0051] In the embodiments provided by the present invention, the water area of ​​the lock or lift is 120×18m, and the scanning angle of the laser rangefinder is ±45 degrees, that is, L0=18m, θ=45°. Therefore, the maximum distance of the laser rangefinder in this embodiment is: D=18×tan45°×2=36m.

[0052] To eliminate blind spots, the angles of the two sets of laser rangefinders must overlap to a certain extent. Although theoretically one set of laser rangefinders can be installed every 36m, to ensure system reliability, the monitoring range of adjacent laser rangefinders must partially cover each other. Therefore, the installation interval is set to 20m, and a total of 5 sets need to be installed every 120m.

[0053] Laser rangefinders are set at both ends of the ranging space. The direction of movement of the moving target is determined by the position of the laser rangefinder that first measures a smaller distance value, and the initial angle of each laser rangefinder is determined by the direction of movement.

[0054] In the embodiments provided by the present invention, a set of laser rangefinders is also installed 1m away from the anti-collision steel wire rope on the inner side of the upper and lower compartments. These rangefinders are used for both accurate distance measurement of the bow of the passing ship (bow collision point) and for determining the direction of the ship entering the compartment. A total of 7 sets are used.

[0055] Once the vessel enters, the first set of rangefinders closest to the entrance activates. All rangefinders are initially set to the maximum angle biased towards the entrance of the ship compartment (determined by the upstream or downstream operation of the lock or ship lift). When the distance measured by the rangefinder 1 meter from the anti-collision cable changes, it indicates that a vessel has entered the compartment, and all rangefinders initialize and enter standby mode.

[0056] When the distance measured by the laser rangefinder changes beyond a set threshold, the automatic scanning control system controls the laser rangefinder to swing horizontally to reduce the angle of the laser rangefinder. The angle of the laser rangefinder is the angle between the laser emitted by the laser rangefinder and the direction of movement.

[0057] The information processing system determines the moving speed of the target based on the time when the two distance values ​​change beyond a set threshold, the angle of the laser rangefinder, and the horizontal distance between the moving target and the laser rangefinder.

[0058] In practical engineering applications, the anti-collision steel wire rope is installed at a height of 0.55m above the water surface. If the rangefinder is also installed at this height, it is easily affected by the cooling water of the ship's engine and is also very easily blocked by personnel and equipment on the freeboard on both sides of the ship, which will affect the normal operation of the system.

[0059] To solve the above problems, in practical engineering applications we will install the rangefinder at a height d above the water surface (the height can be tentatively set at 3 meters). Therefore, when measuring the "bow collision point", the rangefinder has a vertical pitch angle α.

[0060] The moving target's movement speed is:

[0061]

[0062] L1 represents the horizontal distance between the moving target and the laser rangefinder. t1 and t2 are the times when the distance changes exceed a set threshold, respectively. θ1 and θ2 are the angles between the projection direction of the laser emitted by the rangefinder onto the horizontal plane and the horizontal direction when the distance changes exceed the set threshold. The horizontal direction is perpendicular to the direction of movement; when this angle is in the positive direction of movement, the angle value is negative.

[0063] In practice, the range of θ1 and θ2 is -45° to 45°. When the ship enters, the set of rangefinders closest to the entrance will start to move. When the distance measured by the rangefinder is significantly different from that without the ship, the time t1 is recorded and the rangefinder will rotate a certain step. The angle at this time is recorded as θ1. When the distance measured by the rangefinder is significantly different from that without the ship again, the time t2 is recorded and the rangefinder will rotate again. The angle at this time is recorded as θ2. This continues until the angle of the rangefinder reaches 45°.

[0064] L1×(tanθ1-tanθ2)=L1×(tan(θ1-θ2))(1+tanθ1×tanθ2), therefore the ship's speed is:

[0065]

[0066] Preferably, the horizontal distance between the central axis of the moving target and the laser rangefinder is L1 = L0 × cosθ0, where L0 is the distance measured by the laser rangefinder when the angle between the laser rangefinder and the horizontal direction is θ0.

[0067] Preferably, the information processing system further includes:

[0068] The real-time distance between the moving target and the destination is calculated as: S = N × lL × sinθ + x + Δs.

[0069] N represents the number of laser rangefinders remaining after the current laser rangefinder, l represents the distance between the laser rangefinders, θ represents the angle between the current laser rangefinder and the horizontal direction, L represents the distance measured by the current laser rangefinder, x represents the distance between the laser rangefinder at the endpoint and the endpoint, and Δs represents the system error.

[0070] In practice, S is the distance between the hull and the anti-collision steel cable, and S = N × lL × sinθ + 1 + Δs.

[0071] As can be seen from the above formula, the measurement accuracy of the system is determined by the subdivision of the angle. Using a basic servo motor, 4800 subdivisions can be achieved very easily, that is, a step of 90° / 1200 = 0.075°, achieving a measurement accuracy of tan0.075×18×2 = 0.046m / s.

[0072] Because the anti-collision steel wire rope is installed at a height of 0.55m above the normal water surface, while the rangefinder is installed at a height of d meters above the water surface, there is a pitch angle between the rangefinder and the plane of the anti-collision steel wire rope. When the position of the hull entering the compartment is different (Note: when the ship enters the compartment, its longitudinal axis trajectory does not coincide with the longitudinal centerline of the compartment), the intersection point of the laser beam of the hull and the rangefinder may not be on the plane of the anti-collision steel wire rope, or not at the forefront of the ship, or even outside the scanning range, thus bringing measurement errors.

[0073] The error Δs is caused by two factors. First, because the pitch angle of the rangefinder is fixed, when the ship's course is different, the plane where the laser beam of the rangefinder intersects with the ship is not in the plane of the anti-collision steel cable. The shape of the ship is different at different intersection points, which will bring a certain measurement error. Second, because the pitch angle of the rangefinder is fixed, when the ship's course is different, the intersection point of the laser beam of the rangefinder with the ship is not at the forefront of the ship (bow collision point), but may be on the side or even outside the scanning range.

[0074] The pitch angle of the rangefinder and the position of the hull when entering the compartment do not affect the system's measurement error of the hull's speed; its measurement accuracy is determined only by the subdivision of the rotation angle. The measurement error caused by different hull entry positions mainly affects the measurement error Δs of the distance between the hull and the anti-collision steel cable. To minimize the impact of Δs... Figure 4 The diagram shown illustrates the working principle of the laser rangefinder achieving automatic calibration according to an embodiment of the present invention. Figure 4 The following methods are used to correct the system in this embodiment of the invention:

[0075] 1. The height of the two laser rangefinders set at both ends of the ranging space is the same as the height of the moving target.

[0076] In practice, two sets of laser rangefinders at the entrance and exit of the ship's compartment (i.e., closest to the anti-collision steel cable) are installed within the plane height of the anti-collision steel cable, aligned with the plane of the anti-collision steel cable. This ensures that when the ship enters the range of the last rangefinder, the distance and trajectory between the bow of the ship and the front anti-collision steel cable (beam) can be accurately measured (on the same horizontal plane) (Note: directly and accurately measuring the dynamic distance between the "bow collision point" and the anti-collision steel cable).

[0077] The range of the last distance measuring instrument is tan45°×L', where L' is the vertical distance from the ship's centerline to the freeboard on one side of the distance measuring instrument, which is generally ≥5m. Therefore, it can ensure that the measurement accuracy at a distance of 5m from the anti-collision steel wire rope is 0.035 meters.

[0078] S = N × lL × sinθ + 1 + Δs.

[0079] Since the rangefinder and the anti-collision steel wire rope are on the same plane, Δs=0, θ≤45°, the systematic error is mainly determined by the measurement error of the rangefinder itself, which is generally <0.05m.

[0080] 2. The laser rangefinder that first measures a decrease in distance value is identified as the first laser tester. The information processing system performs linear fitting on the trajectory of the moving target along the direction of movement measured by the first laser tester. Based on the trajectory, the vertical distance L' between the moving target and the side of the ranging space where the laser rangefinder is located is determined. The pitch angle of the other laser rangefinders is adjusted as: α = arctan L' / d, where d is the installation height of the other laser rangefinders.

[0081] In practice, the two sets of ranging systems closest to the anti-collision steel wire rope work in the plane of the anti-collision steel wire rope, and can directly and accurately measure the dynamic distance and trajectory between the "bow collision point" and the anti-collision steel wire rope. However, the other ranging systems in the middle have a certain pitch angle, which will also bring measurement errors.

[0082] To address this issue, the system utilizes a No. 1 rangefinder operating within the plane of the anti-collision wire rope for calibration. This rangefinder accurately measures the longitudinal trajectory of the hull (bow collision point). The information processing system uses linear fitting based on the actual trajectory of the "bow collision point" measured by the No. 1 rangefinder to virtually generate an equivalent trajectory. Multiple averaging or median filtering algorithms are then applied to improve the accuracy and reliability of the virtual trajectory. The intermediate rangefinders (No. 2-6) automatically adjust their pitch angles based on the virtual trajectory, ensuring that the intersection point with the hull remains at the forefront of the ship (bow collision point) and within the plane of the anti-collision wire rope. When the ship enters the scanning range of the No. 7 rangefinder, its actual trajectory is obtained.

[0083] After fitting the trajectory of the ship measured by distance measuring instrument No. 1, the vertical distance between it and the freeboard on one side of the distance measuring system is L'. The installation height of distance measuring instrument No. 2 is d. Then, the pitch angle α of the distance measuring instrument is automatically adjusted according to the following formula: α=arctan L' / d. Ship position measurement formula: S=N×lL×sinθ+1+Δs.

[0084] According to the virtual trajectory of the ship's movement, the distance measuring instrument and the anti-collision cable are on the same plane, Δs = 0. However, the actual trajectory of the ship is not a straight line. The deviation in the trajectory does not affect the speed measurement, and the actual displacement of the ship can be accurately calculated based on the relationship between speed and time. However, because there is a certain deviation between the actual displacement of the ship and the virtual trajectory, there is a very small error Δs in the actual positional relationship between the bow collision point and the anti-collision cable before reaching the measurement range of the last distance measuring instrument. The system's position measurement accuracy is... With the accumulation of large amounts of measurement parameters and the enhancement of the system's autonomous learning capabilities, the virtual trajectory of a ship can increasingly approximate its actual trajectory, and Δs will become smaller or even eliminated. When the ship enters the scanning range of the last rangefinder, the actual trajectory of the ship can be accurately measured, and the distance between the bow collision point and the anti-collision steel cable can be accurately calculated with an accuracy of 0.035m.

[0085] When there is a significant deviation between the actual and virtual trajectories of a vessel, it may fall out of the scanning range. Since the rangefinder is installed 3 meters above the water surface, when the vessel's height is 3 meters or more above the water, even if the vessel is close to the rangefinder's hull, it will not fall out of the scanning range. Only when the vessel deviates from the hull away from the rangefinder will a "missing target" phenomenon occur. When the vessel's height is less than 3 meters above the water, a "missing target" phenomenon may also occur when it deviates from the rangefinder's hull, but the probability is much lower. Therefore, when the system determines that the vessel has "missed the target," it first increases the rangefinder's pitch angle. If the angle is increased to the upper limit β = arctan18 / 3 = 80.5° and the vessel is still not found, the rangefinder's pitch angle is then decreased until the vessel is located.

[0086] This invention provides an automatic scanning laser ranging system. Targeting the actual application scenarios and operating conditions of ship locks or ship lifts, it develops a dynamic display system for the distance between ships and anti-collision devices. Through field verification, it achieves the objective of dynamically displaying the ship's speed entering the lock for both upstream and downstream vessels, the distance between the ship's bow and the anti-collision steel cable (beam) at the upper (or lower) bow of the lock, and providing audible and visual warnings. It can collect and process the position and speed information of upstream and downstream vessels within the lock around the clock. It dynamically displays the distance between the bow of an upstream vessel and the anti-collision steel cable (beam) at the upper bow of the lock (on the same horizontal plane), the distance between the bow of a downstream vessel and the anti-collision steel cable (beam) at the lower bow of the lock (on the same horizontal plane), and the ship's speed within the lock. It features automatic overspeed alarms and color-changing speed data. When a ship approaches the anti-collision steel cable, it triggers a red strobe light warning. The system automatically stops detection when there is no boat and automatically starts detection when a boat is present. It can display and store detection data, parameter settings, and other information on-site. It communicates with the computer monitoring system of the lock or ship lift and is linked to the broadcast system. The entire system operates stably and reliably, and its overall technical parameters and performance indicators meet the operational requirements of the lock or ship lift.

[0087] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0088] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0089] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0090] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0091] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0092] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0093] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An automatic scanning laser ranging system, characterized in that, The ranging system includes: a laser rangefinder, an automatic scanning control system, and an information processing system; The laser rangefinder is positioned on the horizontal side of the moving target along the direction of movement and measures the distance value in real time under the control of the automatic scanning control system. When the distance value measured by the laser rangefinder changes beyond a set threshold, the automatic scanning control system controls the laser rangefinder to swing horizontally to reduce the angle of the laser rangefinder. The angle of the laser rangefinder is the angle between the laser emitted by the laser rangefinder and the direction of movement. The information processing system determines the moving speed and / or position of the moving target based on the time when the two distance value changes exceed a set threshold, the angle of the laser rangefinder, and the horizontal distance between the moving target and the laser rangefinder.

2. The automatic scanning laser ranging system according to claim 1, characterized in that, The number of laser rangefinders is set according to the width of the ranging space in the horizontal direction and the angle range of the laser rangefinders. Each laser rangefinder is set at equal distances so that the moving target is within the monitoring range of at least one laser rangefinder. The horizontal direction is the direction perpendicular to the direction of movement on the horizontal plane.

3. The automatic scanning laser ranging system according to claim 2, characterized in that, The maximum distance between each of the laser rangefinders is: D = 2L max ×tanθ max ; among which, L max Let θ be the width of the distance measurement space in the horizontal direction. max The maximum angle between the laser rangefinder and the horizontal direction, which is the direction perpendicular to the direction of movement on the horizontal plane.

4. The automatic scanning laser ranging system according to claim 2, characterized in that, The laser rangefinders are respectively set at both ends of the ranging space. The moving direction of the moving target is determined according to the position of the laser rangefinder that first measures the distance value to be small. The initial angle of each laser rangefinder is determined according to the moving direction.

5. The automatic scanning laser ranging system according to claim 1, characterized in that, The moving target's speed is: L1 represents the horizontal distance between the moving target and the laser rangefinder. t1 and t2 are the times when the distance changes exceed the set threshold, respectively. θ1 and θ2 are the angles between the projection direction of the laser emitted by the laser rangefinder onto the horizontal plane and the horizontal direction when the distance changes exceed the set threshold.

6. The automatic scanning laser ranging system according to claim 5, characterized in that, The horizontal distance between the central axis of the moving target and the laser rangefinder is L1 = L0 × cosθ0, where L0 is the distance measured by the laser rangefinder when the angle between the laser rangefinder and the horizontal direction is θ0.

7. The automatic scanning laser ranging system according to any one of claims 2-4, characterized in that, The information processing system also includes: The real-time distance between the moving target and the destination is calculated as: S = N × lL × sinθ + x + Δs; N represents the number of laser rangefinders remaining after the current laser rangefinder, l represents the distance between the laser rangefinders, θ represents the angle between the current laser rangefinder and the horizontal direction, L represents the distance measured by the current laser rangefinder, x represents the distance between the laser rangefinder at the endpoint and the endpoint, and Δs represents the system error.

8. The automatic scanning laser ranging system according to claim 4, characterized in that, The two laser rangefinders set at opposite ends of the ranging space are at the same height as the moving target.

9. The automatic scanning laser ranging system according to claim 8, characterized in that, The laser rangefinder that first measures a decrease in distance value is identified as the first laser tester. The information processing system performs linear fitting on the trajectory of the moving target along the direction of movement measured by the first laser tester. Based on the trajectory, the vertical distance L' between the moving target and the side of the ranging space where the laser rangefinder is located is determined. The pitch angle of the other laser rangefinders is adjusted as: α = arctan L' / d, where d is the installation height of the other laser rangefinders.

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