CN116592841A - Level measuring device - Google Patents

Abstract

The application discloses a level measuring device, and belongs to the technical field of measurement. The level measuring device includes: a housing; the sealed cavity is provided with a transparent glass window and is fixed on the shell, and mercury is filled in the cavity to the volume of 1/3-2/3 of the cavity; the permanent magnet is fixed below the cavity; the reflector, the laser, the imaging lens and the image sensor are all fixed on the shell. The laser beam emitted by the laser irradiates the top surface of mercury through a transparent window on the cavity to form reflection, the reflected light is emitted out of the cavity through the transparent window and is emitted to an imaging lens through a reflecting mirror, a detection signal is generated at an image sensor, and the positioning accuracy can reach the micron level; and the data processing and displaying unit is connected with the image sensor and calculates the horizontal dip angle according to the image signal. By reflecting the laser beam by utilizing mercury to form an absolute horizontal reference, the magnetic field enables the mercury to be fast and stable, the reflecting mirror prolongs the light path, and the measured light is amplified, so that the accuracy and the sensitivity of the horizontal dip angle measurement are improved.

Description

Level measuring device

Technical Field

The application belongs to the technical field of measurement, and particularly relates to a horizontal measuring device.

Background

The level measuring device widely used at present usually adopts a sealed glass tube, and the vertical section of the inner surface is an arc surface with a certain curvature radius. The glass tube of the level is filled with a liquid having a small viscosity coefficient, such as alcohol, diethyl ether, a mixture thereof, and the like, and the portion without the liquid is generally called a leveling bubble. When the posture of the device changes relative to the horizontal, the position of the blister also moves. There is a certain relation between the radius of curvature of the longitudinal section of the inner surface of the glass tube and the graduation value, and the inclination of the measured plane can be measured according to the relation. However, such a leveling device is not high in accuracy and sensitivity, and is not suitable for a field requiring high accuracy.

Disclosure of Invention

The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides a level measuring device with high precision and high sensitivity.

The present application provides a level measurement device comprising: a housing; the sealed cavity is fixed on the shell, at least part of the cavity wall is transparent, mercury is filled in the cavity, and the volume of the mercury is smaller than the volume in the cavity; a magnetic field generating unit mounted below the cavity and configured to form a magnetic field in the cavity; the laser is fixed on the shell, laser beams emitted by the laser irradiate to the top surface of mercury through the transparent cavity wall on the cavity to form reflection, and reflected light is emitted out of the cavity through the transparent cavity wall; the image sensor is fixed on the shell and positioned on a reflection light path of the cavity, reflected light is projected to the image sensor, and the image sensor generates a detection signal based on the projection position; and a display unit connected with the image sensor and configured to display a horizontal inclination angle of the horizontal measuring device based on the detection signal.

According to the horizontal measuring device, the absolute horizontal reflecting surface is formed in the closed cavity by utilizing mercury, the laser beam is reflected on the absolute horizontal surface, and the reflected light is imaged by adopting the image sensor and the display unit, so that automatic reading is realized.

According to one embodiment of the application, the volume of mercury is 1/2 to 2/3 of the volume in the cavity.

According to one embodiment of the application, the magnetic field generating unit comprises a permanent magnet.

According to one embodiment of the application, the level measuring device further comprises: the first reflector is fixed on the shell and is positioned on the reflecting light path of the cavity, and the reflecting light is reflected to the imaging component through the first reflector.

According to one embodiment of the application, the level measuring device further comprises: the second reflector is fixed on the shell and is positioned on the incident light path of the cavity, and the laser beam is reflected to mercury through the second reflector.

According to one embodiment of the application, an imaging assembly includes: the image sensor is fixed on the shell and positioned on a reflection light path of the cavity, reflected light is projected to the image sensor, and the image sensor generates a detection signal based on the projection position; and a display unit connected with the image sensor and configured to display a horizontal inclination angle of the horizontal measuring device based on the detection signal.

According to one embodiment of the application, the image sensor is a line image sensor.

According to one embodiment of the application, the level measuring device further comprises: the cylindrical lens is fixed on the shell and is positioned on the reflection light path of the cavity, the lens spreads the reflection light into stripe light, and the stripe light is projected to the linear array image sensor.

According to one embodiment of the application, the level measuring device further comprises: the power module is fixed on the shell, connected with the image sensor and the processing unit and used for supplying power to the image sensor and the processing unit.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of a level measuring device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a measuring principle of a level measuring device according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a level measuring device according to an embodiment of the application.

Reference numerals:

the device comprises a housing 10, a cavity 20, mercury 21, a laser 30, an imaging assembly 40, an image sensor 41, a display unit 42, a magnetic field generating unit 50, a first reflecting mirror 60, a second reflecting mirror 70, a lens 80, and a power module 90.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.

A level measuring apparatus according to an embodiment of the present application is described below with reference to the accompanying drawings.

Referring to fig. 1, the present application provides a level measurement device. In this embodiment, the level measuring apparatus includes a housing 10, a closed cavity 20, a laser 30, an imaging assembly 40, and a magnetic field generating unit 50; the cavity 20 is fixed on the shell 10, at least part of the cavity wall is transparent, mercury 21 is filled in the cavity 20, and the volume of the mercury 21 is smaller than the internal volume of the cavity 20; the magnetic field generating unit 50 is installed below the cavity 20 and configured to form a magnetic field inside the cavity 20; the laser 30 is fixed on the shell 10, the laser beam emitted by the laser 30 irradiates to the top surface of mercury 21 through the transparent cavity wall on the cavity 20 to form reflection, and the reflected light emits out of the cavity 20 through the transparent cavity wall; the imaging assembly 40 includes an image sensor 41 and a display unit 42, the image sensor 41 is fixed to the housing 10 and located on a reflection light path of the cavity 20, the reflection light is projected to the image sensor 41, and the image sensor 41 generates a detection signal based on the projection position; the display unit 42 is connected to the image sensor 41 and configured to display a horizontal inclination angle of the horizontal measurement device based on the detection signal.

In some embodiments, the housing 10 may be closed, the housing 10 being provided with a sealed cavity. The cavity 20, laser 30 and imaging assembly 40 are secured in a cavity within the housing 10. The housing 10 has the effect of isolating the cavity 20, the laser 30 and the imaging assembly 40 from the outside, avoiding the measurement results from being affected by external factors; while also protecting the cavity 20, laser 30, and imaging assembly 40.

The top surface of mercury 21 is an absolute horizontal surface. Mercury 21 is stored in the cavity 20, and under the action of gravity, the mercury 21 is located at the bottom of the cavity 20. Therefore, the inclination of the liquid surface of mercury 21 other than the top surface is the same as the inclination of the bottom side surface of the cavity 20. Because the cavity 20 is hollow in the upper area of the mercury 21, the top surface of the mercury 21 is not limited by the shape of the cavity 20, so that a horizontal flat surface is formed under the action of gravity.

When the level measuring device is used for measuring, the mercury 21 in the cavity 20 can be gradually stabilized in a back and forth shaking process when the pose changes, and the fluctuation of the reading can be caused. In this embodiment, because the mercury 21 has conductivity, when a magnetic field is formed in the cavity 20, an induced current is generated when the mercury 21 shakes, and this current has a damping effect, so that the mercury 21 is quickly stabilized, and the result reading is quickly stabilized.

In the present embodiment, the posture of the laser 30 and the imaging module 40 is fixed with respect to the housing 10 after being fixed to the housing 10. I.e. the outgoing laser light of the laser 30 is fixed with respect to the outgoing direction of the housing 10, and the imaging plane of the imaging assembly 40 is fixed with respect to the arrangement direction of the housing 10.

It will be appreciated that as the horizontal attitude of the overall level measuring device changes, the attitude of the housing 10, cavity 20, laser 30 and imaging assembly 40 also changes, but the relative positions and attitudes between the components do not change. When the attitude of the cavity 20 changes, the mercury 21 flows under the action of gravity and, after the entire level measuring device is stationary, the absolute level is reformed. The changed absolute level is different from the absolute level before the change in posture relative to the housing 10, so that the laser beam emitted by the laser 30 is reflected at different angles, and finally the projection position of the laser beam on the imaging assembly 40 is changed.

Referring to fig. 2, fig. 2 shows a variation of the laser beam with the housing 10 as a reference. In some embodiments, the level measuring device may be flipped up and down. It will be appreciated that when the horizontal attitude of the entire level measuring device is inclined by an angle β, the top surface of the mercury 21 can be regarded as being inclined by an angle- β with the housing 10 as a reference. Before the posture of the leveling device changes, the projection position of the laser beam emitted by the laser 30 on the imaging surface P of the imaging component 40 is D0 after the laser beam is reflected by the reflecting surface S; after the attitude of the leveling device is changed, the laser beam emitted from the laser 30 is reflected by the reflecting surface S', and then the projection position on the imaging surface P of the imaging unit 40 is D1, and the reflected light angle is changed to-2β. Assuming that the optical path length from the reflection point of the top surface of mercury 21 to the imaging surface of imaging element 40 is L, the distance between D0 and D1 is Δ=l·tg2β. The offset of the laser beam projection position before and after the attitude change of the leveling device is delta. It can be seen that the horizontal measuring device provided in this embodiment converts the measurement of the minimum inclination angle in the horizontal direction into the measurement of the displacement of the reflected light spot, and the relationship between the displacement and the inclination angle is: the tangent of the double angle is multiplied by a long distance, so that the measured tiny amount is greatly amplified, and finally, high-precision and high-sensitivity measurement is realized.

It should be noted that the level measuring device may be calibrated at a strictly calibrated level position prior to use. The laser beam emitted by the laser 30 is now projected onto the imaging assembly 40 at a horizontal null position. With continued reference to fig. 2, assuming that D0 is a horizontal null, when the leveling device is disposed on the measured object, the projection position of the laser beam emitted by the laser 30 on the imaging assembly 40 is D1, which indicates that the horizontal tilt angle of the measured object is β.

In other embodiments, the level measuring device may be tilted in both the up-down direction and the front-back direction, and the tilt angle may be decomposed into the up-down direction tilt and the front-back direction tilt. Taking the imaging plane of the front-view imaging assembly 40 as an example, after the horizontal measuring device tilts in two directions, the projection position of the laser beam on the imaging assembly 40 deviates in two directions relative to the horizontal zero position, for example, the projection position after tilting is positioned above left, below right or above right of the horizontal zero position. Also, the imaging assembly 40 marks the tilt angle of the leveling device with the deviation value of the projection position according to the relationship between the projection position and the deflection angle.

It should be understood that, after the image sensor 41 is fixed to the housing 10, its position and posture is stationary with respect to the housing 10. The image sensor 41 has the same magnitude of posture change when the posture of the leveling device changes. When the posture of the leveling device changes, the image sensor 41 senses different projection positions, and then generates different detection signals.

As an example, the level measuring device may be tilted in one direction, in which case the detection signal comprises a voltage signal, the voltage value of which voltage signal may be indicative of the offset value between the projected position and the horizontal zero position. For example, when the projection position is at a horizontal zero position, the voltage is zero; when the projection position is positioned in the first direction of the horizontal zero position, the voltage is a positive value; the voltage is negative when the projection position is in the second direction of the horizontal null. Wherein the first direction is the upper direction and the second direction is the lower direction.

In another example, the level measuring device may be tilted in two directions, where the detection signal comprises two voltage signals, the voltage value of each voltage signal being indicative of the offset value between the projected position and the horizontal zero position in a certain direction. For example, one voltage signal represents a projection deviation in a horizontal direction in the imaging plane, and the other voltage signal represents a projection deviation in a vertical direction in the imaging plane. Of course, the specific form of the detection signal may be set according to the requirement, which is not limited in this embodiment.

In some embodiments, the display unit 42 may include a processor and a display, where the processor determines an offset value between the projected position and the horizontal zero position by identifying the detection signal, and calculates an angle value based on a conversion relationship between the offset value and the angle value, and the display displays the angle value.

In some embodiments, the display unit 42 may also be disposed outside the housing 10, with the display unit 42 being communicatively coupled to the image sensor 41. The display unit 42 receives the detection signal transmitted from the image sensor 41 to calculate a corresponding tilt angle.

In the present embodiment, the image sensor 41 and the display unit 42 are used to image the reflected light, so as to realize automatic reading, and eliminate the error of manual reading; meanwhile, mercury has good damping property in a magnetic field, and can be quickly stabilized after the posture of the horizontal measuring device is changed, so that the reading efficiency and accuracy are improved. Second, mercury stabilizes quickly to avoid internal flow from affecting reflection. In general, reflection of the liquid is likely to cause errors due to internal flow unevenness, and thus the image sensor 41 is likely to recognize abnormalities.

According to the level measuring device, the mercury 21 is utilized to form an absolute horizontal plane in the closed cavity 20, the laser beam is reflected on the absolute horizontal plane, and the image sensor and the display unit are adopted to image reflected light, so that automatic reading is realized.

In some embodiments of the application, the volume of mercury is 1/2 to 2/3 of the internal volume of the cavity 20.

It should be appreciated that too little mercury volume tends to result in a small area of absolute horizontal surface, and thus, when the level measuring device is tilted too much, the laser beam emitted by the laser 30 cannot be reflected and measurement cannot be performed. In addition, too much mercury volume, a smaller hollow area within the cavity 20, as well as a smaller area in absolute horizontal may result.

In some embodiments, the interior of the cavity 20 may include a first cavity and a second cavity from a small downward, wherein the cross-sectional area of the first cavity is larger than the cross-sectional area of the second cavity, the top surface of mercury is at least partially within the first cavity, and the walls of the first cavity are transparent. Thus, the top surface of the mercury can be made to have a larger area, while the mercury can also have a first thickness.

In some embodiments, the material of the cavity 20 may be transparent glass. The laser beam emitted from the laser 30 is projected through the glass onto the top surface of mercury and reflected through the glass. The laser beam is refracted when passing through the glass from the outside to the inside and from the inside to the outside, but according to the optical principle, the refraction of the laser beam passing through the glass does not change the overall angle of the laser beam, namely the angle of the laser beam before entering the glass and the angle of the laser beam after exiting the glass are the same.

In some embodiments of the present application, the magnetic field generating unit 50 includes a permanent magnet.

The permanent magnet is installed below the cavity 20, and the permanent magnet does not need to be externally excited, so that the cost can be reduced.

Referring to fig. 3, in some embodiments of the present application, the level measuring device may further include a first mirror 60, where the first mirror 60 is fixed to the housing 10 and is located on a reflection light path of the cavity 20, and the reflection light is reflected to the imaging assembly 40 by the first mirror 60.

In some implementations, the first mirror 60 can be one or more. The reflected light is reflected once again by the first mirror 60 one or more times and finally projected to the imaging assembly 40. After the first reflecting mirror 60 is fixed to the housing 10, its position and posture are stationary with respect to the housing 10. The first mirror 60 has the same magnitude of attitude change when the attitude of the leveling device is changed.

The reflection optical path of the cavity 20 is an optical path of the reflected light of the laser beam reflected by the mercury 21, and the first mirror 60 is located on the reflection optical path and can reflect the reflected light. With reference to the foregoing, in the case where the offset angle is fixed, the longer the optical path length of the reflected light reflected by the mercury 21 is projected to the imaging assembly 40, the greater the offset of the light projection position from the nominal horizontal zero position. Thus, the first mirror 60 can function to increase the optical path length in a smaller space, thereby improving the sensitivity of measurement.

In addition, considering the limitation of the mounting manner of the cavity 20 and the imaging assembly 40, the reflected light reflected from the cavity 20 may not be projected to the imaging assembly 40, so that the reflected light reflected from the cavity 20 is reflected again by the first mirror 60, and the mounting flexibility of the cavity 20 and the imaging assembly 40 may be improved.

According to the leveling device of the present embodiment, the first mirror 60 is provided on the reflection light path of the cavity 21, so that the optical path of the reflected light projected onto the imaging module 40 is improved, the inclination angle change of the leveling device is caused to form a larger position shift on the imaging module 40, and the sensitivity of the inclination angle measurement is improved.

In some embodiments of the present application, the level measuring device may further include a second reflecting mirror 70, where the second reflecting mirror 70 is fixed to the housing 10 and is located on the incident light path of the cavity 20, and the laser beam is reflected to the mercury 21 by the second reflecting mirror 70.

In some implementations, the second mirror 70 can be one or more. The laser beam emitted from the laser 30 is reflected one or more times by the second mirror 70 and finally projected to the mercury 21 in the cavity 20. After the second reflecting mirror 70 is fixed to the housing 10, its position and posture are stationary with respect to the housing 10. The second mirror 70 has the same magnitude of change in attitude as the attitude of the leveling device changes.

In consideration of the limitation of the mounting manner of the cavity 20 and the laser 30, the laser beam emitted from the laser 30 may not be projected to the cavity 20, so that the second mirror 70 is used to reflect the laser beam emitted from the laser 30, and the mounting flexibility of the cavity 20 and the laser 30 may be improved.

As an example, the cavity 20, the laser 30, and the imaging assembly 40 are all secured to the bottom of the interior cavity of the housing 10. The laser 30 emits a laser beam in an obliquely upward direction. The first and second mirrors 60 and 70 are fixed to the top inside the housing 10. The first reflecting mirror 60 is positioned to receive the laser beam and to project the reflected light in a diagonally downward direction toward the mercury 21 within the cavity 20. The second reflecting mirror 70 is positioned to receive the light reflected by the mercury 21 and to project the re-reflected light in a diagonally downward direction to the imaging assembly 40.

In some embodiments of the present application, the image sensor 41 is a line image sensor. The line image sensor may be a CCD image sensor or a CMOS image sensor. CMOS image sensors are a typical solid-state imaging sensor and share a historical source of attention with CCDs. The CCD image sensor is made of a semiconductor material with high sensitivity, can convert light into electric charge, and converts the electric charge into digital signals through an analog-to-digital converter chip, and the digital signals are stored by a flash memory or a built-in hard disk card in the camera after being compressed. CMOS image sensors are typically composed of an array of image sensitive cells, row drivers, column drivers, timing control logic, AD converters, data bus output interfaces, control interfaces, etc., all typically integrated on the same silicon die. The structure and principle of the linear array image sensor are already mature technology, and the embodiment is not described here again.

In other embodiments, the image sensor 41 may also be a position sensitive device PSD (Position Sensitive Detector). A PSD position sensor is an optical detector that can measure the continuous position of a light spot on the detector surface. The PSD position sensor is a non-split type device which can convert the position of a light spot on a photosensitive surface into an electric signal. The PSD position sensor consists of a p-substrate, a pin photodiode and a surface resistor, and the working principle of the PSD position sensor is a mature technology, and the implementation is not repeated here.

In some embodiments of the present application, the leveling device may further include a cylindrical lens 80, wherein the cylindrical lens 80 is fixed to the housing 10 and is located on the reflection path of the cavity 20, and the cylindrical lens 80 spreads the reflection light into stripe light and projects the stripe light to the line image sensor.

In some implementations, the reflective optical path of the cavity 20 may also be provided with a first mirror 60. The lens 80 is located behind the first reflecting mirror 60 on the optical path, that is, the reflected light emitted from the cavity 20 is reflected again by the first reflecting mirror 60, and then is converged by the cylindrical lens 80 and then projected to the linear array image sensor.

In some embodiments, the striped light formed by the lenticular lens 80 may be arranged in a horizontal direction or a vertical direction along the sensing surface of the linear image sensor. Thus, the offset of the level measuring device in two directions can be converted into an offset measurement for one direction. For example, the stripe light is arranged in a horizontal direction along a sensing surface of the line image sensor, a horizontal deviation of the sensing surface due to the inclination of the horizontal measuring device is eliminated, and the line image sensor outputs a detection signal of an offset value to the vertical direction.

In some embodiments of the present application, the level measuring device may further include a power module 90, where the power module 90 is fixed to the housing 10 and connected to the image sensor 41 and the processing unit 42 to supply power to the image sensor 41 and the processing unit 42.

In some embodiments, the power module 90 may include a battery or the like. The power module 90 may be provided in the housing 10 together with the image sensor 41 and the processing unit 42 to improve safety. Meanwhile, the power module 90 also needs to be fixed, so that damage caused by shaking is avoided.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of the application, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by another feature therebetween.

In the description of the application, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the application, the scope of which is defined by the claims and their equivalents.

Claims (8)

1. A level measurement device, comprising:

a housing;

a closed cavity fixed on the shell, at least part of the cavity wall is transparent, mercury is filled in the cavity, and the volume of the mercury is smaller than the volume of the cavity;

a magnetic field generating unit mounted below the cavity and configured to form a magnetic field in the cavity;

the laser is fixed on the shell, laser beams emitted by the laser irradiate to the top surface of mercury through the transparent cavity wall on the cavity to form reflection, and reflected light is emitted out of the cavity through the transparent cavity wall;

the image sensor is fixed on the shell and is positioned on a reflection light path of the cavity, the reflection light is projected to the image sensor, and the image sensor generates a detection signal based on the projection position;

and a display unit connected with the image sensor and configured to display a horizontal inclination angle of the horizontal measuring device based on the detection signal.

2. The level measuring device of claim 1, wherein the volume of mercury is 1/2 to 2/3 of the volume within the cavity.

3. The level measuring device according to claim 1 or 2, wherein the magnetic field generating unit comprises a permanent magnet.

4. The level measuring device according to claim 1 or 2, characterized in that the level measuring device further comprises:

the first reflector is fixed on the shell and is positioned on the reflecting light path of the cavity, and the reflecting light is reflected to the imaging component through the first reflector.

5. The level measurement device of claim 4, further comprising:

and the second reflector is fixed on the shell and is positioned on the incident light path of the cavity, and the laser beam is reflected to the mercury through the second reflector.

6. The level measuring device according to claim 1 or 2, wherein the image sensor is a line image sensor.

7. The level measurement device of claim 6, further comprising:

the cylindrical lens is fixed on the shell and is positioned on the reflection light path of the cavity, and the lens spreads the reflection light into stripe light and projects the stripe light to the linear array image sensor.

8. The level measuring device according to claim 1 or 2, characterized in that the level measuring device further comprises:

and the power module is fixed on the shell, is connected with the image sensor and the processing unit and is configured to supply power to the image sensor and the processing unit.