Hand-held laser depth finder

Abstract

This utility model relates to the field of laser detection equipment technology, and in particular to a handheld laser depth sounder, comprising a main unit, which includes a main housing, inside which are a green laser ranging module and a near-infrared laser ranging module; a main control board is also provided, which is connected to the green laser ranging module and the near-infrared laser ranging module and calculates the water depth; an optical window is provided on the front surface of the main housing; the laser rangefinder also includes a handheld part, with the main unit located at the top of the handheld part, and the axes of the handheld part and the main unit are set at an angle; the handheld laser rangefinder is based on phase ranging technology, does not require a probe, can realize non-contact measurement, is low in cost, easy to carry, can perform single-point real-time depth measurement, and is simple and convenient to acquire data, without the need to calculate the latitude and longitude of the measurement location, is not limited by the incident angle during measurement, the laser beam propagation speed in the water is stable, not easily affected by water temperature and salinity, and has high ranging accuracy.

Description

Technical Field

[0001] This utility model relates to the field of laser detection equipment technology, and in particular to a handheld laser depth sounder. Background Technology

[0002] Water depth measurement plays a vital role in underwater topographic exploration, water resource management, and navigation safety. Currently, commonly used handheld or portable depth sounders mainly employ acoustic depth sounding technology, and the equipment is primarily in the form of a single-beam echo sounder.

[0003] The typical structure and working principle of existing handheld single-beam depth sounders are as follows: Figure 1 As shown, it vertically emits sound wave signals into the water through a transducer installed below the device. When the sound waves reach the bottom of the water, they are reflected, and the reflected echo signal returns and is received by the transducer. By measuring the time required for the sound waves to travel back and forth in the water, and combining this with the average speed of sound in the water, the water depth is calculated.

[0004] Multibeam echo sounders are another type of acoustic ranging device. However, due to their wider coverage and higher detection efficiency, multibeam echo sounders are typically used for large-scale underwater topographic mapping in deep water or deep sea areas. In shallow water areas such as shallow seas, islands, reefs, pools, and reservoirs, single-beam echo sounders, which are simpler in structure and easier to operate, are more commonly used.

[0005] Existing handheld or portable single-beam echo sounders typically rely on long probe connection cables to transmit transducer signals, resulting in poor operational flexibility and hindering rapid deployment and application in field operations and complex aquatic environments.

[0006] Based on the above shortcomings, there is an urgent need for a water depth measurement device that can complete the measurement without the probe touching the water surface, effectively avoids the influence of environmental factors, has high ranging accuracy and is easy to use, so as to improve the reliability and practicality of water depth measurement. Utility Model Content

[0007] To address the shortcomings of the existing technology, this utility model provides a handheld laser depth sounder that is simple in structure, easy to use, and capable of instantly acquiring water depth values.

[0008] This utility model provides a handheld laser depth sounder, comprising:

[0009] The main unit includes a main unit housing, and a green laser ranging module and a near-infrared laser ranging module are disposed inside the main unit housing.

[0010] The green laser ranging module is used to measure the one-way optical path from the outlet of the green laser ranging module to the bottom of the water; the near-infrared laser ranging module is used to measure the one-way optical path from the outlet of the near-infrared laser ranging module to the surface of the water.

[0011] The main control board is also installed inside the main unit housing. The main control board is connected to the green laser rangefinder and the near-infrared laser rangefinder for transmitting and receiving data and control signals, and for calculating water depth.

[0012] An optical window is provided on the front surface of the main unit housing, through which the lasers emitted by the green laser rangefinder and the near-infrared laser rangefinder are emitted.

[0013] A display screen is provided on the rear end face of the main unit housing, and the display screen is used to display the water depth value calculated by the main control board;

[0014] The laser rangefinder also includes a handheld part, and the main unit is provided at the top of the handheld part. The axes of the handheld part and the main unit are arranged at an angle.

[0015] The handheld laser depth sounder of this technical solution has a simple structure and is easy to operate. Based on phase ranging technology, it does not require a probe and can realize non-contact measurement, making testing convenient. The laser beam has a stable propagation speed in water and is not easily affected by water temperature and salinity, resulting in high ranging accuracy.

[0016] In some embodiments of this application, the handheld part is a hollow cuboid or cylindrical structure, and a battery compartment is provided inside the handheld part. The battery compartment contains a battery for powering the laser rangefinder.

[0017] In some embodiments of this application, a switch button is provided on the outside of the handheld part, and the switch button controls the opening and closing of the laser rangefinder.

[0018] In some embodiments of this application, the main unit housing is a hollow cuboid structure, the bottom surface of the main unit housing is fixed to the top surface of the handheld part, the handheld part is positioned close to the display screen for convenient operation during measurement, and the display screen faces the observer for easy observation and operation.

[0019] In some embodiments of this application, in order to make the measurement results more accurate, the optical path of the green laser and the near-infrared laser is equal on the water surface to avoid the influence of water surface undulation. A reflector is provided inside the main housing and below the outlet of the near-infrared laser ranging module. A dichroic mirror is provided inside the main housing and below the outlet of the green laser ranging module. The dichroic mirror can transmit the green laser emitted by the green laser ranging module and reflect the near-infrared laser.

[0020] The near-infrared laser emitted by the near-infrared laser ranging module is reflected by the reflector and the dichroic mirror, and then emitted coaxially with the green laser emitted by the green laser ranging module.

[0021] In some embodiments of this application, the reflective surface of the reflector is set at a 45° angle to the near-infrared laser emission direction emitted from the outlet of the near-infrared laser ranging module, and its reflective surface faces the green laser ranging module.

[0022] The dichroic mirror is set parallel to the reflector, so that the near-infrared laser emitted from the outlet of the near-infrared laser ranging module is reflected by the reflector and its emission direction is perpendicular to the green laser emitted by the green laser ranging module. After the near-infrared laser is further reflected by the dichroic mirror, the near-infrared laser and the green laser are emitted coaxially, which improves the accuracy of the measurement.

[0023] In some embodiments of this application, a GPS module and an attitude sensor are also provided inside the main housing. The GPS module is used to determine the coordinate information of the measurement position, and the attitude sensor is used to measure the incident angle of the laser rangefinder.

[0024] The main control board is connected to the attitude sensor and the GPS module. The main control board calculates the refraction angle based on the incident angle measured by the attitude sensor, and calculates the water depth based on the optical path measured by the green laser ranging module, the optical path measured by the near-infrared laser ranging module, and the refraction angle.

[0025] In some embodiments of this application, in order to increase the measurement depth, the power of the green laser ranging module is greater than or equal to 10mW, the aperture of the receiving lens is greater than or equal to 20mm, and stray light is filtered out by a narrow-band filter.

[0026] In some embodiments of this application, both the main casing and the handheld part are sealed structures, which can effectively prevent moisture.

[0027] Based on the above technical solution, the handheld laser depth sounder of this utility model can be held by hand. Compared with the acoustic rangefinder, it is based on phase ranging technology, does not require a probe, can realize non-contact measurement, has low cost, is easy to carry, and is simple to operate. It can perform single-point real-time depth measurement, and the data acquisition is simple and convenient. During measurement, there is no need to calculate the latitude and longitude of the measurement position. The measurement is not limited by the incident angle. Even if the incident angle is not perpendicular to the water surface, the water depth value can still be measured accurately. The propagation speed of the laser beam in the water is stable and is not easily affected by the water temperature and salinity. The ranging accuracy is high.

[0028] The placement of the reflector and dichroic mirror allows the green laser and near-infrared laser to be emitted coaxially, resulting in more accurate measurement results. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0030] Figure 1 This is a schematic diagram of the structure of a single-beam depth sounder in the prior art;

[0031] Figure 2 This is a schematic diagram of the structure of a handheld laser rangefinder according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram illustrating the relationship between water depth calculation and other parameters in an embodiment of this utility model.

[0033] Figure 4 This is a control block diagram of the main control board in an embodiment of the present utility model;

[0034] Figure 5 This is a schematic diagram of the display structure of the display screen according to an embodiment of the present utility model.

[0035] In the diagram, 10 is a single-beam depth sounder; 20 is a handheld device; 21 is a battery compartment; 22 is a power switch; 30 is the main unit; 31 is the main housing; 311 is an optical window; 312 is a display screen; 3121 is a calibration button; 3122 is a refractive index setting button; 3123 is a data save button; 32 is a green laser ranging module; 33 is a near-infrared laser ranging module; 34 is an attitude sensor; 35 is a GPS module; 36 is a main control board; 37 is a reflector; and 38 is a dichroic mirror. Detailed Implementation

[0036] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0037] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0038] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] While existing single-beam depth sounders offer advantages such as simple implementation principles and wide application range, they also have significant drawbacks. Firstly, because sound waves cannot propagate directly between air and water, the probe must be placed in water, such as... Figure 1 As shown, this increases operational complexity, and the probe, exposed to the aquatic environment for extended periods, is susceptible to contamination, corrosion, or biofouling, affecting measurement stability and equipment lifespan. Furthermore, the propagation speed of sound waves is significantly influenced by environmental factors such as salinity and temperature, leading to measurement errors and making it difficult to maintain consistency and high accuracy under varying water quality conditions.

[0041] To address the aforementioned problems, this embodiment provides a handheld laser depth sounder, such as... Figure 2 As shown, it includes a handheld part 20 and a main unit 30. To facilitate the use of the measuring personnel, the handheld part 20 and the main unit 30 are set at an angle of 90° or greater, which facilitates the operation of the measuring personnel. The main unit 30 is located at the top of the handheld part 20.

[0042] The main unit 30 includes a main unit housing 31, which is a hollow cuboid structure. A green laser ranging module 32 and a near-infrared laser ranging module 33 are installed inside the main unit housing 31.

[0043] The green laser ranging module 32 uses laser phase ranging technology to measure the one-way optical path from the green laser ranging module's output port to the bottom of the water. In order to increase the measurement depth, a larger power is required. Therefore, the power of the green laser ranging module in this embodiment is greater than or equal to 10mW, the aperture of the receiving lens is greater than or equal to 20mm, and a narrow band filter is also required to filter out stray light.

[0044] The near-infrared laser ranging module 33 also employs laser phase ranging technology to measure the one-way optical path from the outlet of the near-infrared laser ranging module to the water surface. To ensure more accurate measurement results, the optical path lengths of the green laser and the near-infrared laser on the water surface are equal to avoid errors caused by tilted incident on the water surface. A reflector 37 is installed below the outlet of the near-infrared laser ranging module 33. The angle α between the reflector surface of the reflector 37 and the emission direction of the near-infrared laser emitted from the outlet of the near-infrared laser ranging module 33 is 45°, and its reflector surface faces the green laser ranging module 32. This ensures that the near-infrared laser emitted from the outlet of the near-infrared laser ranging module 33 is reflected by the reflector 37 and its emission direction is perpendicular to the original emission direction and also perpendicular to the transmission direction of the green laser emitted from the green laser ranging module 32 before being transmitted to the green laser.

[0045] A dichroic mirror 38 is disposed below the outlet of the green laser ranging module 32. The dichroic mirror 38 is arranged parallel to the reflector 37. The dichroic mirror 38 can transmit the green laser emitted by the green laser ranging module 32 and reflect the near-infrared laser emitted by the near-infrared laser ranging module 33. After being reflected by the reflector 37, the near-infrared laser is incident on the dichroic mirror 38. After being reflected by the dichroic mirror 38, it is coaxially emitted with the green laser emitted by the green laser ranging module 32, which improves the accuracy of the measurement.

[0046] The main unit housing 31 also houses an attitude sensor 34 and a GPS module 35; the attitude sensor 34 is used to measure the angle of incidence of the handheld laser rangefinder. The GPS module 35 is used to determine the coordinates of the measurement location for each measurement.

[0047] Furthermore, such as Figure 3 As shown, the main unit 30 also includes a main control board 36. The main control board 36 is connected to the green laser ranging module 32, the near-infrared laser ranging module 33, the attitude sensor 34, and the GPS module 35. The main control board 36 is used to transmit and receive data and control signals. The main control board 36 determines the incident angle measured by the attitude sensor. Calculate the angle of refraction , ;

[0048] in, The incident angle of the green laser light is measured by the attitude sensor. The refractive index of green laser light in air. The refractive index of green laser light in water;

[0049] And based on the optical path measured by the green laser ranging module 32 The optical path measured by the near-infrared laser ranging module 33 Angle of refraction Calculate the water depth H.

[0050] .

[0051] See also Figure 2 An optical window 311 is provided on the front surface of the main unit housing 31. The near-infrared laser emitted by the near-infrared laser ranging module 33 is reflected by the reflector 37 and then incident on the dichroic mirror 38. After being reflected by the dichroic mirror 38, it is coaxial with the green laser emitted by the green laser ranging module 32 and emitted through the optical window 311.

[0052] A display screen 312 is provided on the rear surface of the main casing 31. The display screen 312 is used to display the water depth H. The display screen 312 faces the observer for easy observation and operation. Figure 5 The device includes a calibration button 3121, a refractive index setting button 3122, and a data save button 3123.

[0053] See also Figure 2 In this embodiment, the handheld part 20 is a hollow cuboid structure. In other embodiments, the handheld part 20 can also be a cylindrical structure for easy gripping by the tester. A battery compartment 21 is provided inside the handheld part 20, housing a battery that powers the main control board 36, green laser ranging module 32, near-infrared laser ranging module 33, attitude sensor 34, and GPS module 35 within the laser rangefinder. A switch button 22 is provided on the handheld part 20 to control the handheld laser rangefinder's on / off state.

[0054] Both the handheld part 20 and the main body shell 31 of the handheld laser rangefinder are designed with a sealed structure, which can effectively prevent moisture by sealing the whole machine.

[0055] The handheld laser rangefinder of this embodiment requires distance calibration during use. This calibration can be performed in a laboratory by measuring the distance to a known calibration target. The calibration target can be a laboratory wall. The distance from a point to the laboratory wall can be measured using a ruler; this distance is easily obtained. The green laser ranging module 32 measures the distance to the calibration target as follows: The near-infrared laser ranging module 33 measured the distance to the calibration target as follows: ,in The distance from the near-infrared laser rangefinder's output port to the reflector 37 is added to the horizontal distance from the reflector 37 to the dichroic mirror 38, plus the distance from the dichroic mirror 38 to the calibration target.

[0056] Calibration value of green laser ranging module 32 for: ;

[0057] Calibration value of near-infrared laser ranging module 33 for: ;

[0058] After calibration, the green laser ranging module 32 and the near-infrared laser ranging module 33 improve the accuracy of the measurement. In particular, after calibration of the near-infrared laser ranging module 33, the influence of the distance between the reflector 37 and the dichroic mirror 38 on the measurement results can be eliminated.

[0059] Upon reaching the water area to be measured, use the handheld laser rangefinder, turn on switch 22, and set the water refractive index for the area. The handheld laser rangefinder can measure at any angle. The green laser ranging module 32 measures the one-way optical path from its output port to the bottom of the water. The near-infrared laser ranging module 33 measures the one-way optical path from the outlet of the near-infrared laser ranging module 33 to the water surface. ;like Figure 4 As shown, calculate the one-way optical path L between the water surface and the bottom. ;

[0060] Calculate the angle of refraction , ,

[0061] in, The angle of incidence is measured by the attitude sensor. The refractive index of green laser light in air. The refractive index of green laser light in water;

[0062] Therefore, the water depth H is: .

[0063] The water depth H value is displayed on screen 312 and can be saved for later viewing.

[0064] The handheld laser rangefinder described in this implementation can measure the distance from the laser emitter to the water surface and the laser emitter to the bottom of the water in one operation. It can also quickly obtain the water depth measurement results through calculation. The test is convenient, and the laser phase ranging technology can achieve a ranging accuracy of millimeters, resulting in high measurement accuracy. The setting of the reflector and dichroic mirror allows the green laser and near-infrared laser to be emitted coaxially, making the measurement results more accurate.

[0065] Laser light travels at a stable speed in water, unaffected by water temperature and salinity, ensuring accurate measurements. Laser rangefinders are handheld and, compared to acoustic rangefinders, do not require a probe. They are simple in structure, low in cost, portable, and easy to operate. They can perform real-time single-point depth measurement, providing simple and convenient data acquisition. During measurement, there is no need to calculate the latitude and longitude of the measurement location, and the measurement is not limited by the incident angle. Even if the incident angle is not perpendicular to the water surface, an accurate water depth value can still be measured.

[0066] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0067] The above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A handheld laser depth sounder, characterized in that, include, The main unit includes a main unit housing, and a green laser ranging module and a near-infrared laser ranging module are disposed inside the main unit housing. The green laser ranging module is used to measure the one-way optical path from the outlet of the green laser ranging module to the bottom of the water; the near-infrared laser ranging module is used to measure the one-way optical path from the outlet of the near-infrared laser ranging module to the surface of the water. The main control board is also installed inside the main unit housing. The main control board is connected to the green laser rangefinder and the near-infrared laser rangefinder for transmitting and receiving data and control signals, and for calculating water depth. An optical window is provided on the front surface of the main unit housing, through which the lasers emitted by the green laser rangefinder and the near-infrared laser rangefinder are emitted. A display screen is provided on the rear end face of the main unit housing, and the display screen is used to display the water depth value calculated by the main control board; The laser rangefinder also includes a handheld part, and the main unit is provided at the top of the handheld part. The axes of the handheld part and the main unit are arranged at an angle.

2. The handheld laser depth sounder according to claim 1, characterized in that, The handheld part is a hollow cuboid or cylindrical structure, and a battery compartment is provided inside the handheld part. The battery compartment contains a battery used to power the laser rangefinder.

3. The handheld laser depth sounder according to claim 2, characterized in that, A switch button is provided on the outside of the handheld part, and the switch button controls the opening and closing of the laser rangefinder.

4. The handheld laser depth sounder according to claim 1, characterized in that, The main unit housing is a hollow cuboid structure, with the bottom surface of the main unit housing fixed to the top surface of the handheld part, and the handheld part positioned close to the display screen.

5. The handheld laser depth sounder according to claim 1, characterized in that, A reflector is provided inside the main unit housing and below the output port of the near-infrared laser ranging module. A dichroic mirror is provided inside the main unit housing and below the output port of the green laser ranging module. The dichroic mirror can transmit the green laser emitted by the green laser ranging module and reflect the near-infrared laser. The near-infrared laser emitted by the near-infrared laser ranging module is reflected by the reflector and the dichroic mirror, and then emitted coaxially with the green laser emitted by the green laser ranging module.

6. The handheld laser depth sounder according to claim 5, characterized in that, The reflective surface of the reflector is set at a 45° angle to the near-infrared laser emission direction emitted from the outlet of the near-infrared laser ranging module, and its reflective surface faces the green laser ranging module. The dichroic mirror is set parallel to the reflector, so that the near-infrared laser emitted from the outlet of the near-infrared laser ranging module is reflected by the reflector and its emission direction is perpendicular to the green laser emitted by the green laser ranging module. After the near-infrared laser is further reflected by the dichroic mirror, the near-infrared laser and the green laser are emitted coaxially.

7. The handheld laser depth sounder according to claim 1, characterized in that, The main unit housing also includes a GPS module and an attitude sensor. The GPS module is used to determine the coordinate information of the measurement location, and the attitude sensor is used to measure the incident angle of the laser rangefinder. The main control board is connected to the attitude sensor and the GPS module. The main control board calculates the refraction angle based on the incident angle measured by the attitude sensor, and calculates the water depth based on the optical path measured by the green laser ranging module, the optical path measured by the near-infrared laser ranging module, and the refraction angle.

8. The handheld laser depth sounder according to claim 1, characterized in that, The green laser ranging module has a power of ≥10mW, a receiving lens aperture of ≥20mm, and uses a narrow-band filter to filter out stray light.

9. The handheld laser depth sounder according to claim 1, characterized in that, Both the main casing and the handheld part are sealed structures.

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