CN113532580A - System and method for optically locating and measuring the level of a liquid in a transparent container - Google Patents

Abstract

The invention relates to a liquid level positioning system in an optical non-contact transparent container, which comprises a bracket module; the master control module receives the illumination processing value, judges the movement direction of the slide rail, receives the height value of the slide block and converts the height value into a liquid level height value; the motion control module receives a motion control command and controls the slide rail to move; the positioning module is used for transmitting and receiving light rays and measuring an illumination value; the calculation module receives the illumination value, calculates the average value or integral and obtains an illumination processing value; and the height measuring module measures to obtain the height value of the sliding block. The invention also relates to a positioning method, comprising the following steps: starting the light emitting unit; driving the slide block to move upwards; continuously collecting illuminance values; calculating an average value or an integral value to obtain an illumination processing value; judging the motion direction of the slide rail; controlling the slide rail to move until stopping; measuring the height value of the sliding block; and converting to obtain a liquid level height value. The invention has higher measurement precision; can greatly approach the critical position of the liquid level.

Description

System and method for optically locating and measuring the level of a liquid in a transparent container

Technical Field

The invention relates to the technical field of precise positioning and measurement of transparent liquid level, in particular to a positioning system and a method of liquid level in an optical non-contact transparent container.

Background

Liquid level measurement is a widely used technique, which simply means measuring the level of liquid in a container; the technical difficulty is the precise positioning and measurement of the liquid level, which is due to the fact that the liquid rises or falls along the wall of the container due to wetting or non-wetting in the container, for example, the phenomenon that the edge of water rises along the wall in a glass bottle is wetting, and the phenomenon that the edge of mercury column falls along the wall in a glass tube is non-wetting. In a transparent tube, the level of the water and mercury column will thus present an approximately spherical concave or convex level.

There are many methods for measuring the liquid level in the prior art, and there are, but not limited to, the following examples of the related art, buoyancy, pressure, reflection, and electrical characteristics. For example, the conventional float-type liquid level positioning method applies a buoyancy-type measuring principle; the buoyancy type has the following defects:

because the density of the liquid changes under the influence of temperature or the measured medium changes, the immersion depth of the floater in the liquid correspondingly changes, and certain positioning deviation is easily introduced.

The prior art is based on radar, ultrasonic wave and guided wave radar of the reflection principle; the reflective type has the defect that the resolution is generally low due to the limitation of the technology, and the requirements of high-precision positioning and measurement are difficult to meet.

In addition, there are some new research results in the field, which adopts the non-contact reflection type measuring principle. The invention is typically a technology disclosed in the patent application No. CN201710433696.0 entitled "novel detecting device for tracking and positioning precise change of liquid level of measuring cylinder and detecting method thereof". The main principle is as follows: two pairs of infrared transmitting and receiving tubes are horizontally arranged perpendicular to the axis of the transparent glass tube, one pair of transmitting and receiving axes passes through the axis of the glass tube, the other pair of transmitting and receiving axes passes through the side of the glass tube, and the axes of the two infrared transmitting and receiving tubes are parallel to each other. When the plane of the infrared transmitting and receiving tube moves from top to bottom and sequentially passes through the air section, the liquid surface section and the liquid section below the glass tube, a photoelectric value function curve of the infrared transmitting and receiving axis passing through the axis of the glass tube is a quadratic function curve with an upward opening, a photoelectric value of the transmitting and receiving axis passing through the side of the glass tube is a monotonically decreasing function curve (a limiting condition should be provided, the photoelectric value is in the liquid surface section and the adjacent areas above and below the liquid surface section), and the lower intersection point of the two curves is a liquid level positioning point.

The drawbacks of this technique are:

1. because the liquid level is comprehensively positioned by adopting the photoelectric value interactive relationship of two pairs of infrared transmitting and receiving tubes, the influence of the distance between infrared transmitting axes and the diameter difference of the glass tube on the measurement result is not considered, and the measurement error caused by the distance between the axes and the tube diameter cannot be eliminated;

2. because the relation between two pairs of infrared transmitting and receiving photoelectric light values and different positions of the liquid level is not clear enough, the concave liquid level is simply regarded as a crescent, and the refraction and reflection of the crescent area irradiated by light rays are too general. Therefore, whether the relative height position relations among the transmitting and receiving axis, the curve intersection point and the actual liquid level expressed by the method are consistent or not is not clear, so that the measurement result obtained by the method is an empirical value which always contains unknown system errors;

3. because the method finds a point which uses the intersection point of two simulation curves as liquid level positioning, and the inference can correct the relative height difference between the point and an actual measurement point through system correction so as to achieve the purpose of accurate liquid level positioning, how to find a better liquid level positioning method to obtain a theoretically relatively correct reference value becomes the key point of system correction, but the method does not provide a corresponding technical scheme, so that the practicability of the method is influenced to a certain extent on the premise that the key technical scheme is not determined.

Disclosure of Invention

The invention aims at the problems and provides a system and a method for optically positioning and measuring the liquid level of liquid in a transparent container, aiming at improving the measurement precision by a plurality of orders of magnitude compared with the prior art and ensuring that the measurement precision is higher; the critical position of the liquid level can be greatly approached.

In order to solve the problems, the technical scheme provided by the invention is as follows:

a system for optically locating and measuring the level of a liquid in a transparent container, comprising the following modules:

a support module: comprises a base, a pillar, a slide rail and a slide block; the support column is vertically and fixedly arranged on the upper surface of the base; the slide rail is detachably connected with the support column and is arranged on the same side of the base as the support column; the extending direction of the slide rail is vertical to the upper surface of the base; the sliding block is connected with the sliding rail in a sliding mode, and the sliding direction of the sliding block is parallel to the extending direction of the sliding rail;

the master control module: the device comprises a calculation module, a motion control module, a height measurement module, a slide block height value and a liquid level height value, wherein the calculation module is used for receiving an illumination processing value from the calculation module, judging the motion direction of the slide block at the next moment according to the illumination processing value at the current moment and combining with a manually preset processing mode, packaging the motion direction into a motion control instruction and sending the motion control instruction to the motion control module, and the device is also used for receiving the slide block height value of the height measurement module, converting the slide block height value into the liquid level height value and outputting the liquid level height value; the direction of motion includes "up," "down," and "stop"; the master control module is electrically coupled with the motion control module; the master control module is electrically coupled with the computing module; the master control module is electrically coupled with the height measuring module; the processing modes include an averaging mode and an integrating mode;

a motion control module: the sliding block is used for receiving a motion control instruction from the master control module and controlling the sliding block to make corresponding motion according to the motion control instruction; the motion control module comprises a moving mechanism for driving the sliding block to move;

a positioning module: for emitting light, receiving light, and measuring an illuminance value of the received light; the positioning module is fixedly arranged on the sliding block and comprises a light emitting unit and a light illuminance measuring unit; the positioning module is coupled with the computing module through an electric signal and sends the illumination value of the received light to the computing module in real time; the light emitting unit emits light with a certain thickness and parallel to a horizontal plane; the light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit;

a calculation module: the illumination processing module is used for receiving the illumination value from the positioning module, carrying out average value calculation or integral calculation on the illumination value to obtain an illumination processing value and sending the illumination processing value to the master control module;

a height measurement module: the distance measuring device is used for measuring the distance between the sliding block and an artificially preset initial position to obtain the height value of the sliding block, and then the height value of the sliding block is sent to the main control module.

Preferably, the pillars are square pillars.

Preferably, the light emitting unit comprises a laser emitter, or a visible light emitter, or a monochromatic light emitter, or an infrared light emitter, or a near-ultraviolet light emitter.

Preferably, the light emitting unit further includes a slit for filtering the light emitted from the laser emitter; the emitting slit, the light emitting end of the laser emitter and the light receiving end of the light illuminance measuring unit are coaxial and are horizontally equal in height.

Preferably, the light emitting unit further comprises a right-angle prism for dividing the light emitted by the laser emitter into two symmetrical lights; two light rays split by the right-angle prism are parallel to a horizontal plane and have the same height, and are coaxial with the light ray receiving end of the light ray illuminance measuring unit and have the same horizontal height.

Preferably, the light illuminance measuring unit adopts an illuminance sensor, or an illuminometer.

Preferably, the height measuring module comprises a grating ruler, a capacitance grating ruler or a magnetic grating ruler; the height measuring module is detachably connected with the square upright post, and the extending direction of the height measuring module is parallel to the extending direction of the square upright post; and the sliding part of the height measuring module is fixedly connected with the sliding block.

A method for optically locating and measuring the level of a liquid in a transparent container using the system for optically locating and measuring the level of a liquid in a transparent container, comprising the steps of:

s100, adjusting the posture of the support module to enable the extending direction of the support to be parallel to the local gravity acceleration direction;

s200, placing a transparent container containing liquid with the height value of the sliding block to be measured on the upper surface of the base; then adjusting the posture of the transparent container to enable the height direction of the transparent container to be parallel to the local gravity acceleration direction;

s300, starting the light emitting unit, and then adjusting the initial position of the sliding block to enable the upper surface of the emitted light to be coplanar with the manually preset initial position; the slider height value is then set to 0.

S400, driving the sliding block to move upwards; in the moving process, the illumination value is continuously collected by the light illumination measuring unit and is sent to the calculating module; setting the time when the sliding block starts to move as an initial time;

s500, performing average value calculation or integral calculation on the contrast values by using the calculation module to obtain the illumination processing values, and sending the illumination processing values to the master control module;

s600, judging the moving direction of the sliding block at the next moment by utilizing the master control module according to the illumination processing value at the current moment and combining a manually preset processing mode;

s700, controlling the sliding block to move correspondingly by using the motion control module according to the motion control instruction until the motion direction is 'stop', stopping the motion of the sliding block, and stopping the light illumination measuring unit from collecting illumination values;

s800, measuring the distance between the slide block and the initial position by using the height measuring module to obtain a slide block height value, and then sending the slide block height value to the main control module;

s900, calculating to obtain the liquid level height value according to the slide block height value by using the main control module, and then outputting the liquid level height value; the liquid level height value is the final result of the method.

Preferably, in S600, the determining, by using the master control module, the moving direction of the slider at the next time according to the illumination processing value at the current time and in combination with a manually preset processing mode specifically includes the following steps:

s610, judging whether the processing mode of the illumination processing value at the current moment is an average value mode or an integral mode, and according to the judgment result, performing the following operations:

if the processing mode at the current moment is the average value mode, executing Sa 620; if the current-time illumination processing value is the illumination integral value, Sb620 is executed;

sa620, utilizing the computing module to perform average value computation again on the illumination value at the current moment and all the illumination values collected from the initial moment to obtain an illumination average value at the current moment;

and Sa621, comparing the illumination value at the current moment with a manually preset illumination average lower limit threshold, and performing the following operations according to the comparison result:

if the illumination value at the current moment is greater than or equal to the illumination average lower limit threshold, setting the motion direction as 'stop'; then, S630 is performed;

otherwise, setting the motion direction to "move up"; then, S630 is performed;

performing integral calculation again on the illumination value at the current moment and all the illumination values collected from the initial moment by using the calculation module to obtain an illumination integral value at the current moment; then calculating the fluctuation amplitude of the illumination integral value;

and Sb621, comparing the fluctuation amplitude of the illumination integral value at the current moment with a manually preset verification amplitude, and performing the following operations according to the comparison result:

setting the movement direction to "stop" if the fluctuation amplitude of the illuminance integral value at the current time is greater than or equal to the approved amplitude; then, S630 is performed;

otherwise, setting the motion direction to "move up"; then, S630 is performed;

s630, packaging the motion direction into a motion control instruction and sending the motion control instruction to the motion control module; then S700 is performed.

Compared with the prior art, the invention has the following advantages:

1. the invention utilizes the characteristic of total internal reflection of light to find the critical characteristic of liquid level positioning, and combines the positioning technology with the high-precision length measurement technology, so that the liquid level measurement precision is improved by a plurality of orders of magnitude compared with the prior art, and the measurement accuracy is improved.

2. By selecting a more sensitive illumination intensity sensor, sampling time interval is reduced, the movement speed of the sliding block is reduced, and the like, so that light can greatly approach the critical position of the liquid level, and the measurement repeatability is improved.

Drawings

FIG. 1 is a schematic diagram of a system architecture according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart of a method according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the optical principles of an application of an embodiment of the present invention;

FIG. 4 is a schematic diagram of optical convergence employed in an embodiment of the present invention;

FIG. 5 is a schematic illustration of optical refraction and reflection analysis applied in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of the apparatus for a single level tube liquid level height positioning measurement experiment of example 1;

FIG. 7 is a schematic elevation view of the apparatus for the dual level tube liquid level height difference positioning measurement experiment of example 2;

FIG. 8 is a schematic side elevation view of the apparatus for the dual level tube liquid level height difference positioning measurement experiment of example 2;

FIG. 9 is a schematic view of the light propagation in example 2.

Wherein: 1. the device comprises a square upright post, 2 a base, 3 a sliding block, 4 a sliding rail, 5 a movable support, 6 a light irradiation axis, 7 an electric moving mechanism, 8 a liquid level tube axis, 9 an emission slit, 10 a receiving slit, 11 a laser emitter, 12 an illumination intensity sensor, 13 a glass tube, 14 a grating ruler, 15 a U-shaped glass tube, 16 a reinforcing rib inclined column, 17 an illuminometer support, 18 an illuminometer mounting position, 19 an illuminometer, 20 a leveling instrument, 21 a right-angled prism, 22 a leveling screw, 23 a ground pad, 24 a display screen, 25 a glass tube support bottom, 26 downlink laser, 27 reflected laser, 28 a glass tube support and 29 a prism support.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be purely exemplary and are not intended to limit the scope of the invention, as various equivalent modifications of the invention will occur to those skilled in the art upon reading the present disclosure and fall within the scope of the appended claims.

It should be noted that the transparent containers in this embodiment are all uniform cylindrical containers, and the height value of the liquid level to be measured is the distance between the liquid level in the vertical direction and the manually preset initial position.

As shown in fig. 1, a system for optically locating and measuring the level of a liquid in a transparent container comprises the following modules:

a support module: comprises a base 2, a pillar, a slide rail 4 and a slide block 3; the pillar is vertically and fixedly arranged on the upper surface of the base 2; the slide rail 4 is detachably connected with the pillar and is arranged on the same side of the base 2 with the pillar; the extending direction of the slide rail 4 is vertical to the upper surface of the base 2; the sliding block 3 is connected with the sliding rail 4 in a sliding manner, and the sliding direction is parallel to the extending direction of the sliding rail 4.

In this embodiment, the support is a square column 1.

The master control module: the device is used for receiving the illumination processing value from the calculation module, judging the movement direction of the slide block (3) at the next moment according to the illumination processing value at the current moment and combining with a manually preset processing mode, packaging the movement direction into a movement control instruction and sending the movement control instruction to the movement control module, and is also used for receiving the slide block height value of the height measurement module, converting the slide block height value into a liquid level height value and outputting the liquid level height value; the direction of motion includes "up," "down," and "stop"; the master control module is electrically coupled with the motion control module; the master control module is electrically coupled with the computing module; the master control module is electrically coupled with the height measuring module; the processing modes include an averaging mode and an integrating mode;

a motion control module: the sliding block (3) is used for receiving a motion control instruction from the master control module and controlling the sliding block to make corresponding motion according to the motion control instruction; the motion control module comprises a moving mechanism for driving the slide block (3) to move;

a positioning module: for emitting light, receiving light, and measuring an illuminance value of the received light; the positioning module is fixedly arranged on the sliding block (3) and comprises a light emitting unit and a light illuminance measuring unit; the positioning module is coupled with the computing module through an electric signal and sends the illumination value of the received light to the computing module in real time; the light emitting unit emits light with a certain thickness and parallel to a horizontal plane; the light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit;

in this embodiment, the light emitting unit includes a laser emitter 11.

It should be further noted that, depending on the application scenario, the light emitting unit further includes an emitting slit 9 for filtering the light emitted by the laser emitter 11, or further includes a right-angle prism 21 for dividing the light emitted by the laser emitter 11 into two symmetrical light; specifically, the method comprises the following steps:

if the emitting slit 9 is included, the emitting slit 9, the light emitting end of the laser emitter 11, and the light receiving end of the light illuminance measuring unit are coaxially equal in height.

If the right-angle prism 21 is included, two light rays split by the right-angle prism 21 are parallel to the horizontal plane and are coaxial and equal in height with the light receiving end of the light illuminance measuring unit.

In either case, the light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit.

In this embodiment, the light illuminance measuring unit employs the illuminance sensor 12 or the illuminometer 19. The light intensity sensor 12 or the light meter 19 is used to collect the light intensity value.

A calculation module: and the illumination processing module is used for receiving the illumination value from the positioning module, carrying out average value calculation or integral calculation on the illumination value to obtain an illumination processing value, and sending the illumination processing value to the master control module.

A height measurement module: the measuring device is used for measuring the distance between the sliding block 3 and an initial position preset manually to obtain a sliding block height value, and then the sliding block height value is sent to the main control module.

In this embodiment, the height measuring module includes a grating 14; the grating ruler 14 is detachably connected with the square upright post 1, and the extending direction of the grating ruler 14 is parallel to the extending direction of the square upright post 1; the sliding part of the grating ruler 14 is fixedly connected with the sliding block 3.

In this specific embodiment, the grating ruler 14 specifically adopts a grating type dial indicator calibrator produced by Shenzhen Zhongji corporation, and the resolution of the product is 0.1 μm, that is, 0.0001 mm.

As shown in fig. 2, a method for optically locating and measuring a liquid level in a transparent container using a system for optically locating and measuring a liquid level in a transparent container, comprising the steps of:

s100, adjusting the posture of the support module to enable the extending direction of the support to be parallel to the local gravity acceleration direction.

S200, placing a transparent container containing liquid with the height value of the sliding block to be measured on the upper surface of the base 2; and then adjusting the posture of the transparent container to enable the height direction of the transparent container to be parallel to the local gravity acceleration direction.

S300, starting the light emitting unit, and then adjusting the initial position of the sliding block 3 to enable the upper surface of the emitted light to be coplanar with the bottom of the inner wall of the transparent container.

S400, driving the sliding block 3 to move upwards; continuously collecting illumination values by using a light illumination measurement unit in the moving process, and sending the illumination values to a calculation module; the time when the slider 3 starts moving is set as the initial time.

S500, average value calculation or integral calculation is carried out on the contrast value by using the calculation module to obtain an illumination processing value, and the illumination processing value is sent to the master control module.

S600, judging the moving direction of the sliding block 3 at the next moment by utilizing the master control module according to the illumination processing value at the current moment and combining a manually preset processing mode, and specifically comprising the following steps:

s610, judging whether the processing mode of the illuminance processing value at the current moment is an average value mode or an integral mode, and according to the judgment result, performing the following operations:

if the processing mode at the current moment is the average value mode, executing Sa 620; sb620 is executed if the current-time illuminance processing value is the illuminance integrated value.

Sa620, utilizing the computing module to perform average value computation again on the illumination value at the current moment and all the illumination values collected from the initial moment to obtain an illumination average value at the current moment;

and Sa621, comparing the illumination value at the current moment with a manually preset illumination average lower limit threshold, and performing the following operations according to the comparison result:

if the illumination value at the current moment is greater than or equal to the illumination average lower limit threshold, setting the motion direction as 'stop'; then, S630 is performed;

otherwise, setting the motion direction as 'upward shift'; then S630 is performed.

Performing integral calculation again on the illumination value at the current moment and all the illumination values collected from the initial moment by using the calculation module to obtain an illumination integral value at the current moment; then calculating the fluctuation amplitude of the illumination integral value;

and Sb621, comparing the fluctuation amplitude of the illumination integral value at the current moment with a manually preset verification amplitude, and performing the following operations according to the comparison result:

setting the movement direction to "stop" if the fluctuation amplitude of the illuminance integral value at the current time is greater than or equal to the approved amplitude; then, S630 is performed;

otherwise, setting the motion direction as 'upward shift'; then S630 is performed.

S630, packaging the motion direction into a motion control instruction and sending the motion control instruction to a motion control module; then S700 is performed.

S700, controlling the sliding block 3 to move correspondingly by using the motion control module according to the motion control instruction until the motion direction is 'stop', stopping the motion of the sliding block 3, and stopping the light illumination measurement unit from collecting the illumination value.

S800, measuring the distance between the slide block 3 and an artificially preset initial position by using a height measuring module to obtain a slide block height value, and then sending the slide block height value to a main control module.

S900, converting the height value of the sliding block by using a main control module to obtain a liquid level height value, and outputting the liquid level height value; the liquid level height value is the final result of the method.

As shown in fig. 3, 4 and 5, the basic principle of the present invention is that when light is irradiated from an optically dense medium to an optically thinner medium, refraction and reflection occur at the interface; at this time, the refracted light ray is deviated from the normal line. The angle between the incident light and the interface normal is defined as the incident angle, when the incident angle is gradually increased to a specific angle, the angle between the refracted light and the normal is 90 degrees, at this time, the light will not be refracted but totally reflect to the optical dense medium, the incident angle at this time is the critical angle, and the phenomenon is the total internal reflection in optics.

Next, it is to be noted that the present invention is applied to a liquid medium in which a wetting or non-wetting phenomenon occurs in a transparent container. This is because the liquid in the transparent container will rise or fall along the wall of the transparent container due to wetting and non-wetting, for example, the edge of water will rise along the wall in the glass bottle as wetting, and the edge of mercury will fall along the wall in the glass tube 13 as non-wetting. In a transparent tube, the level of the water and mercury column will thus present an approximately spherical concave or convex level. Due to the presence of wetting, various attempts to improve the accuracy of level positioning and level height measurement methods are important in precision measurement applications.

Further, the optical phenomenon that occurs when the slider 3 is raised when the present invention is applied will be described in detail below:

taking the transparent container as the uniform cylindrical glass tube 13 as an example, the transparent concave liquid surface soaked in the uniform cylindrical glass tube 13 is taken as a research object, and the optical system formed by the glass tube 13 and the liquid has a light converging effect, although the focal distance is not necessarily the same, the final result is not influenced.

In the first stage, parallel light rays are incident from below the liquid level of the glass tube 13 in parallel to the horizontal plane and perpendicular to the axis of the glass tube 13: at this time, the light rays pass through the glass tube 13 and the liquid and then converge behind the glass tube 13, and at this time, the light rays are not deflected upwards or downwards.

In the second stage, the incident direction of the light source is unchanged, the light source is moved upwards in parallel, and light rays gradually approach the concave liquid surface in parallel: at this stage, when the upper edge of the light ray exceeds the lowest edge of the concave liquid surface, as shown in fig. 5, the incident angle is infinitely close to 90 degrees, the incident angle is larger than the critical angle, the light ray is reflected by the concave liquid surface and is totally internally reflected in a direction slightly deviated below the liquid surface, and no refracted light ray deviated above the liquid surface is generated. At this time, the second light not irradiated to the liquid surface is still converged behind the glass tube 13 through the liquid and the glass tube 13. Therefore, the third light ray that undergoes total internal reflection is totally internally reflected by the concave liquid surface, and the propagation path is changed to be separated from the second light ray that converges behind the glass tube 13. The first detected ray separation can be used as a positioning indicator for the liquid level.

And a third stage, continuing to move the light source upwards: at this stage, the incident angle of the fourth light ray gradually decreases, the deflection angle of the reflected light ray increases, and the light ray totally reflected gradually diffuses downward.

And in the fourth stage, the light source continues to move upwards again, and when the incidence angle of the fifth light ray is smaller than the critical angle: in this stage, the light rays are refracted and reflected simultaneously through the concave liquid surface, the propagation path of the refracted light rays is complex after the refracted light rays are separated from the concave liquid surface, a part of light rays are reflected and propagated again in the upward direction through the liquid surface, and a part of light rays are refracted again through the liquid surface and enter the glass tube 13 downwards. The multiple reflections and refractions of the light through the liquid surface tend to brighten the concave liquid surface and even the entire glass tube 13.

In the fifth stage, the light source continues to move upwards again, and when the sixth light ray moves above the liquid level: at this stage, the light is refracted by the glass tube 13 and then only slightly deflected horizontally, and does not deflect upwards or downwards.

The following describes the application method of the system and method for optically positioning and measuring the liquid level in a transparent container in different scenarios in conjunction with fig. 6 to 9.

Example 1

Example 1 is the specific application of the invention to the positioning and measurement of liquid level height in a single level tube.

The transparent container in example 1 is a single liquid level tube, which is a glass tube 13; the single liquid level pipe is a glass pipe 13; and in order to verify the actual technical effect of the present invention, example 1 was repeated three times, each time using a glass tube 13 of different diameter; the final experimental results are detailed in table 1.

As shown in fig. 6, a system for optically locating and measuring the level of a liquid in a transparent container comprises the following modules:

a support module: comprises a base 2, a pillar, a slide rail 4 and a slide block 3; the pillar is vertically and fixedly arranged on the upper surface of the base 2; the slide rail 4 is detachably connected with the pillar and is arranged on the same side of the base 2 with the pillar; the extending direction of the slide rail 4 is vertical to the upper surface of the base 2; the sliding block 3 is connected with the sliding rail 4 in a sliding manner, and the sliding direction is parallel to the extending direction of the sliding rail 4.

In example 1, the pillars are square pillars 1.

The master control module: the device is used for receiving the illumination processing value from the calculation module, judging the movement direction of the slide block 3 at the next moment according to the illumination processing value at the current moment and combining a manually preset processing mode, packaging the movement direction into a movement control instruction and sending the movement control instruction to the movement control module, and is also used for receiving the slide block height value of the height measurement module, converting the slide block height value into a liquid level height value and outputting the liquid level height value; the direction of motion includes "up", "down", and "stop"; the master control module is electrically coupled with the motion control module; the master control module is electrically coupled with the computing module; the master control module is electrically coupled with the height measuring module; the processing mode includes an averaging mode and an integrating mode.

In embodiment 1, the processing mode is preset to the mean value integration mode.

In embodiment 1, the general control module is implemented by a computer and a programmed program.

A motion control module: the device is used for receiving a motion control instruction from the master control module and controlling the sliding block 3 to move correspondingly according to the motion control instruction; the motion control module comprises a moving mechanism for driving the slider 3 to move.

In embodiment 1, the moving mechanism is an electric moving mechanism 7.

A positioning module: for emitting light, receiving light, and measuring an illuminance value of the received light; the positioning module is fixedly arranged on the sliding block 3 and comprises a light emitting unit and a light illuminance measuring unit; the positioning module is coupled with the computing module through an electric signal and sends the illumination value of the received light to the computing module in real time; the light emitting unit emits light having a certain thickness and being parallel to a horizontal plane.

In embodiment 1, the light emitting unit includes a laser emitter 11. The light emitting unit further comprises an emission slit 9 for filtering the light emitted by the laser emitter 11; specifically, the method comprises the following steps: the emitting slit 9, the light emitting end of the laser emitter 11 and the light receiving end of the light illuminance measuring unit are coaxial and are at the same height horizontally.

The light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit and is horizontally as high as the light.

In embodiment 1, the light illuminance measuring unit employs the illuminance sensor 12.

A calculation module: and the illumination processing module is used for receiving the illumination value from the positioning module, carrying out average value calculation or integral calculation on the illumination value to obtain an illumination processing value, and sending the illumination processing value to the master control module.

A height measurement module: the device is used for measuring the distance between the slide block 3 and an artificial preset initial position to obtain a slide block height value, and then sending the slide block height value to the main control module.

In embodiment 1, the height measuring module includes a grating scale 14; the grating ruler 14 is detachably connected with the square upright post 1, and the extending direction of the grating ruler 14 is parallel to the extending direction of the square upright post 1; the sliding part of the grating ruler 14 is fixedly connected with the sliding block 3.

In the embodiment 1, a U-shaped movable bracket 5 is arranged on the sliding block 3; the movable support 5 is symmetrical, the two support arms are coplanar, and the common plane is vertical to the gravity direction.

In embodiment 1, the laser transmitter 11 is mounted on the outer side of one support arm of the movable support 5, and the transmitting slit 9 is provided on this support arm; the light intensity sensor 12 is installed outside a support arm of the movable support 5, on which a receiving slit 10 is also provided; the width of the transmitting slit 9 and the receiving slit 10 is equal.

In embodiment 1, the grating ruler 14 specifically adopts a grating type dial indicator calibrator manufactured by Shenzhen Zhongji, and the resolution of the product is 0.1 μm, that is, 0.0001 mm.

In example 1, the grating type dial indicator calibrator was vertically arranged such that the measurement axis was vertical. A laser emitter 11 is horizontally fixed at the upper end of the measuring shaft, laser emitted by the laser emitter 11 horizontally irradiates the upright glass tube 13 after passing through the emitting slit 9, and the laser penetrates through the axis of the glass tube 13.

The laser light emitted from the laser emitter 11, the emitting slit 9, the receiving slit 10, and the light receiving end of the light intensity sensor 12 are collinear on the light irradiation axis 6.

Note that the widths of the emission slit 9 and the reception slit 10 are subject to no diffraction by light.

In practical verification, a light intensity sensor is not used, but a display screen 24 is arranged behind the glass tube 13, the display screen 24 is used as a device for displaying light ray changes instead of the sensor, and human eyes observe the light ray changes on the display screen 24.

A method for optically locating and measuring a level of a liquid in a transparent container using a system for optically locating and measuring a level of a liquid in a transparent container, comprising the steps of:

s100, adjusting the posture of the support module to enable the extending direction of the support to be parallel to the local gravity acceleration direction.

S200, placing a glass tube 13 containing liquid with the height value of the sliding block to be measured on the upper surface of the base 2; then adjusting the posture of the glass tube 13 to make the height direction of the glass tube 13 parallel to the local gravity acceleration direction; at this time, the level tube axis 8 is parallel to the local gravitational acceleration direction.

S300, starting the light emitting unit, and then adjusting the initial position of the sliding block 3 to enable the upper surface of the emitted light to be coplanar with the bottom of the inner wall of the glass tube 13.

S400, a computer program in the master control module sends a motion control instruction, and the motion control instruction is 'up' or 'down', so that the sliding block 3 is driven to stably and slowly move upwards or downwards; continuously collecting illumination values by using a light illumination measurement unit in the moving process, and sending the illumination values to a calculation module; the time when the slider 3 starts moving is set as the initial time.

It should be noted that the slider 3 generally has only two motion states, i.e. up and stop, but the "down" motion in the motion control command is still necessary, which is required in the calibration and reset application scenarios.

S500, average value calculation or integral calculation is carried out on the contrast value by using the calculation module to obtain an illumination processing value, and the illumination processing value is sent to the master control module.

S600, judging the moving direction of the sliding block 3 at the next moment by utilizing the master control module according to the illumination processing value at the current moment and combining a manually preset processing mode, and specifically comprising the following steps:

and S610, judging whether the processing mode of the illumination processing value at the current moment is an average value mode or an integral mode.

As described above, the processing mode in embodiment 1 is the average mode, and then Sa620 is executed; sb620 is executed if the current-time illuminance processing value is the illuminance integrated value.

Sa620, utilizing the computing module to perform average value computation again on the illumination value at the current moment and all the illumination values collected from the initial moment to obtain an illumination average value at the current moment;

and Sa621, comparing the illumination value at the current moment with a manually preset illumination average lower limit threshold, and performing the following operations according to the comparison result:

if the illumination value at the current moment is greater than or equal to the illumination average lower limit threshold, setting the motion direction as 'stop'; then, S630 is performed;

otherwise, setting the motion direction as 'upward shift'; then S630 is performed.

S630, packaging the motion direction into a motion control instruction and sending the motion control instruction to a motion control module; then S700 is performed.

S700, controlling the sliding block 3 to move correspondingly by using the motion control module according to the motion control instruction until the motion direction is 'stop', stopping the motion of the sliding block 3, and stopping the light illumination measurement unit from collecting the illumination value.

S800, measuring the distance between the sliding block 3 and the manually preset initial position of the base 2 by using the height measuring module to obtain a sliding block height value, and then sending the sliding block height value to the main control module.

S900, converting the height value of the sliding block by using a main control module to obtain a liquid level height value, and outputting the liquid level height value; the liquid level height value is the final result of the method.

The principle of S100 to S900 is as follows: the plane of the light has a certain thickness; when the upper edge of the light plane crosses the top of the concave liquid surface, the crossed light is reflected by the concave liquid surface to irradiate towards the lower direction, at the moment, the intensity of the light signal sampled by the light intensity sensor 12 begins to gradually weaken, and the numerical value gradually reduces; when the measured value of the illumination intensity sensor 12 reaches the artificially preset descending amplitude, namely the lower limit threshold of the average illumination value, the master control module sends an instruction to perform data sampling on the height measuring module which moves synchronously, and the value is sent to the display screen 24 to be displayed as the height measured value of the liquid level and is sent to the memory to be stored.

It should be noted that there is an error between the measured height and the actual height, the error is the moving distance between the light moving from the top of the concave liquid level to the change of the light measurement value sensed by the light intensity sensor 12, and the moving distance is related to the moving speed of the electric moving mechanism 7, the sampling frequency, the time delay between the illumination sampling and the height sampling, the discrimination threshold of the light intensity sensor 12, and the discrimination threshold of the length measuring mechanism.

Furthermore, the error is also related to the coefficient of thermal expansion and the existence of the material at different temperatures, the influence of the influence factors on the height error is reduced, the true value of the liquid level height can be gradually approached, and the influence of the error on the measurement result is reduced.

From the practical application point of view, the embodiment 1 can also be connected with a container, a water pool and a pump which are vertically installed to form a communicator structure, water is added into the container through the pump to generate different liquid level differences, and the liquid level difference measured by the structure is taken as a standard to calibrate each level gauge with lower accuracy than the device. Meanwhile, embodiment 1 is not limited to the application to the verification of the liquid level meter.

As described at the beginning of example 1, in order to verify the practical technical effect of the invention, example 1 was repeated three times, each time using a glass tube 13 of different diameter; the final experimental results are shown in table 1:

TABLE 1 data table of three experiments in example 1

From table 1, the following two conclusions can be drawn as to the effect of the present invention:

1. the positioning accuracy of the invention can reach more than 0.02 mm.

2. The accuracy of measuring the liquid level of a larger pipe diameter is higher than that of a smaller pipe diameter.

During the experiment it was also found that: the deviation of the measurement result of the liquid level relative height obtained by visual observation is about 0.016 mm-0.030 mm; the reason for the deviation of the measuring method influencing the determination of the light reaching the top of the concave liquid by naked eyes is analyzed as follows:

firstly, the light source adopted by the experimental method is a laser light source, and due to overlarge luminous intensity, visual observation cannot be lasting, fatigue is easy to generate, and personnel deviation is introduced, so that the digital illuminance sensor is reasonable to replace human eyes for observation.

Secondly, the light source of the practical experimental device is diffracted to a certain degree after passing through the slit, the light spot range is expanded, the path of the light rays passing over the vertex of the concave liquid surface is changed after the light rays are reflected, a small distance is formed when the light rays pass through the light spot range, and the light source is moved upwards by a small distance simultaneously when the light rays pass through the distance, so that deviation is introduced.

Finally, the light rays which cross the top point of the concave liquid surface have a divergence phenomenon after being reflected, and the light ray divergence also causes difficulty in distinguishing by naked eyes, so that deviation is introduced.

The main method for solving the problem of the personnel measurement deviation is to adopt an illuminometer 19 with higher sensitivity or other illumination intensity sensors 12, take the descending amplitude of the measurement value of the smaller illumination intensity sensor 12 as an indication mark, wherein the descending amplitude is slightly larger than the fluctuation amplitude of the measurement value of the illumination intensity sensor 12 in the liquid level section, and simultaneously the difference (the difference between the descending amplitude and the fluctuation amplitude) is larger than the identification threshold of the illumination intensity sensor 12.

Example 2

Example 2 is the specific application of the invention to level height positioning and level height difference measurement in a dual level pipe.

The transparent container in example 2 is a U-shaped glass tube 15.

It should be noted that the basic principle of the measurement of the optical positioning type liquid pressure gauge is to measure the height difference between two liquid level surfaces by the following formula: p-g-h allows the pressure difference between the two liquid levels to be calculated and measured.

As shown in fig. 7, 8 and 9, a system for optically locating and measuring the level of a liquid in a transparent container comprises the following modules:

a support module: comprises a base 2, a pillar, a slide rail 4 and a slide block 3; the pillar is vertically and fixedly arranged on the upper surface of the base 2; the slide rail 4 is detachably connected with the pillar and is arranged on the same side of the base 2 with the pillar; the extending direction of the slide rail 4 is vertical to the upper surface of the base 2; the sliding block 3 is connected with the sliding rail 4 in a sliding manner, and the sliding direction is parallel to the extending direction of the sliding rail 4.

In example 2, the pillars are square pillars 1.

In addition, because the whole system is relatively high, in order to prevent the square upright post 1 from deforming and inclining to introduce measurement errors, a reinforcing rib inclined post 16 is arranged behind the square upright post 1.

In addition, due to the shape characteristics of the U-shaped glass tube 15, a glass tube support bottom 25 is arranged on the base 2 for safer arrangement; meanwhile, the U-shaped glass tube 15 is detachably connected with the square upright post 1 through a glass tube rack 28.

In addition, a level 20 is provided on the base 2 for the purpose of facilitating the alignment in the horizontal direction.

In embodiment 2, the floor mat 23 is provided on the bottom surface of the base 2; leveling screws 22 are arranged on the floor mat 23; the leveling screws 22 pass through the base 2, so that the posture of the base 2 can be directly adjusted without turning over the base 2.

The master control module: the device is used for receiving the illumination processing value from the calculation module, judging the movement direction of the slide block 3 at the next moment according to the illumination processing value at the current moment and combining a manually preset processing mode, packaging the movement direction into a movement control instruction and sending the movement control instruction to the movement control module, and is also used for receiving the slide block height value of the height measurement module, converting the slide block height value into a liquid level height value and outputting the liquid level height value; the direction of motion includes "up", "down", and "stop"; the master control module is electrically coupled with the motion control module; the master control module is electrically coupled with the computing module; the master control module is electrically coupled with the height measuring module; the processing mode includes an averaging mode and an integrating mode.

In embodiment 2, the processing mode is preset as the integration mode.

In embodiment 2, the general control unit is composed of a single chip microcomputer, a power supply, an electronic circuit, and a display unit, the single chip microcomputer continuously sends an instruction to acquire an illuminance value output by the illuminance meter 19, and at the same time, performs integral calculation, and when the illuminance drops to an integrated illuminance verification amplitude, sends a length value instruction to acquire the grating scale 14, and inputs the acquired length value to the display screen 24.

A motion control module: the sliding block 3 is used for receiving a motion control instruction from the master control module and controlling the sliding block to move correspondingly according to the motion control instruction; the motion control module comprises a moving mechanism for driving the slider 3 to move.

A positioning module: for emitting light, receiving light, and measuring an illuminance value of the received light; the positioning module is fixedly arranged on the sliding block 3 and comprises a light emitting unit and a light illuminance measuring unit; the positioning module is coupled with the computing module through an electric signal and sends the illumination value of the received light to the computing module in real time; the light emitting unit emits light having a certain thickness and being parallel to a horizontal plane.

In embodiment 2, the light emitting unit includes a laser emitter 11.

It should be further noted that, in embodiment 2, the light emitting unit further includes a right-angle prism 21 for dividing the light emitted by the laser emitter 11 into two symmetrical light; specifically, the method comprises the following steps:

the two reflected laser beams 27 divided by the right-angle prism 21 are parallel to the horizontal plane, and are coaxial with the light receiving end of the light illuminance measuring unit and are horizontally equal in height.

The right-angle prism 21 is arranged on the sliding block 3 through a prism bracket 29; the laser emitter 11 is fixedly arranged at the upper end of the slide rail 4; the downlink laser 26 emitted by the laser emitter 11 changes the propagation direction after passing through the right-angle prism 21, and is divided into two left and right reflected lasers 27; the reflected laser light 27 passes through the receiving slit and is irradiated to the measurement surface of the illuminometer 19.

The light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit.

In example 2, the illuminance meter 19 was used as the light illuminance measuring unit. The illuminometer 19 is used to acquire illuminance values.

The two illuminometers 19 are symmetrically arranged on the sliding block 3 through the illuminometer bracket 17; the illuminometer support 17 is provided with illuminometer mounting positions 18 in bilateral symmetry.

A calculation module: and the illumination processing module is used for receiving the illumination value from the positioning module, carrying out average value calculation or integral calculation on the illumination value to obtain an illumination processing value, and sending the illumination processing value to the master control module.

A height measurement module: the measuring device is used for measuring the distance between the sliding block 3 and an artificially preset initial position to obtain a sliding block height value, and then sending the sliding block height value to the main control module.

In embodiment 2, the height measuring module includes a grating scale 14; the grating ruler 14 is detachably connected with the square upright post 1, and the extending direction of the grating ruler 14 is parallel to the extending direction of the square upright post 1; the sliding part of the grating ruler 14 is fixedly connected with the sliding block 3.

In embodiment 2, the grating ruler 14 specifically adopts a grating type dial indicator calibrator produced in shenzhen middle diagram, and the resolution of the product is 0.1 μm, that is, 0.0001 mm.

The liquid level height difference in the U-shaped glass tube 15 is caused by the fact that the upper end of the U-shaped glass tube 15 is respectively connected with positive pressure and negative pressure, or one end of the U-shaped glass tube 15 is connected with the positive pressure (or the negative pressure) and the other end is connected with the atmosphere, and when pressure difference exists between the two ports, the liquid level in the glass tube 13 generates the height difference.

Example 2 this difference in height was measured.

Method for optically locating and measuring the level of a liquid in a transparent container, comprising the steps of:

s100, adjusting the posture of the support module to enable the extending direction of the support to be parallel to the local gravity acceleration direction.

S200, placing a U-shaped glass tube 15 containing liquid with the height value of the sliding block to be measured on the upper surface of the base 2; then, the posture of the U-shaped glass tube 15 is adjusted so that the height direction of the U-shaped glass tube 15 is parallel to the local gravitational acceleration direction.

S300, moving the sliding block 3 along the sliding rail 4 to enable the right-angle prism 21 to move to the lower portion of the instrument, turning on a single chip microcomputer power supply and a laser power supply, turning on a light emitting unit, then adjusting the initial position of the sliding block 3, and setting the height value of the grating to be 0.

S400, slowly driving the sliding block 3 to move upwards; continuously collecting illumination values by using a light illumination measurement unit in the moving process, and sending the illumination values to a calculation module; the time when the slider 3 starts moving is set as the initial time.

And S500, performing integral calculation on the contrast value by using a calculation module to obtain an illumination processing value, and sending the illumination processing value to a master control module.

S600, judging the moving direction of the sliding block 3 at the next moment by utilizing the master control module according to the illumination processing value at the current moment and combining a manually preset processing mode, and specifically comprising the following steps:

s610, judging whether the processing mode of the illumination processing value at the current moment is an average value mode or an integral mode; as described previously, the processing mode in embodiment 2 is the integration mode, and then Sb620 is executed; the following operations are performed according to the determination result:

as described above, the processing mode in embodiment 2 is preset to the integration mode, and Sb620 is executed.

Performing integral calculation again on the illumination value at the current moment and all the illumination values collected from the initial moment by using the calculation module to obtain an illumination integral value at the current moment; then calculating the fluctuation amplitude of the illumination integral value;

and Sb621, comparing the fluctuation amplitude of the illumination integral value at the current moment with a manually preset verification amplitude, and performing the following operations according to the comparison result:

setting the movement direction to "stop" if the fluctuation amplitude of the illuminance integral value at the current time is greater than or equal to the approved amplitude; then, S630 is performed;

otherwise, setting the motion direction as 'upward shift'; then S630 is performed.

S630, packaging the motion direction into a motion control instruction and sending the motion control instruction to a motion control module; then S700 is performed.

S700, controlling the sliding block 3 to move correspondingly by using the motion control module according to the motion control instruction until the motion direction is 'stop', stopping the motion of the sliding block 3, and stopping the light illumination measurement unit from collecting the illumination value.

S800, measuring the distance of the initial position manually preset by the sliding block 3 by using the height measuring module to obtain the height value of the sliding block, and then sending the height value of the sliding block to the main control module.

And S900, converting the height value of the sliding block by using a main control module to obtain a liquid level height value, and outputting the liquid level height value.

S1000, repeating S400-S900 until another liquid level height value is measured.

S1010, subtracting the height values of the two liquid levels to obtain a liquid level height difference positioning value of the double-liquid-level pipe; the results are sent to the display screen 24 for display.

In the foregoing detailed description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the subject matter require more features than are expressly recited in each claim. Rather, as the following claims reflect, invention lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. To those skilled in the art; various modifications to these embodiments will be readily apparent, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or".

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. A system for optically locating and measuring the level of a liquid in a transparent container, comprising: the system comprises the following modules:

a support module: comprises a base (2), a pillar, a slide rail (4) and a slide block (3); the support is vertically and fixedly arranged on the upper surface of the base (2); the sliding rail (4) is detachably connected with the support column and is arranged on the same side of the base (2) with the support column; the extending direction of the slide rail (4) is vertical to the upper surface of the base (2); the sliding block (3) is connected with the sliding rail (4) in a sliding mode, and the sliding direction is parallel to the extending direction of the sliding rail (4);

the master control module: the device is used for receiving the illumination processing value from the calculation module, judging the movement direction of the slide block (3) at the next moment according to the illumination processing value at the current moment and combining with a manually preset processing mode, packaging the movement direction into a movement control instruction and sending the movement control instruction to the movement control module, and is also used for receiving the slide block height value of the height measurement module, converting the slide block height value into a liquid level height value and outputting the liquid level height value; the direction of motion includes "up," "down," and "stop"; the master control module is electrically coupled with the motion control module; the master control module is electrically coupled with the computing module; the master control module is electrically coupled with the height measuring module; the processing modes include an averaging mode and an integrating mode;

a motion control module: the sliding block (3) is used for receiving a motion control instruction from the master control module and controlling the sliding block to make corresponding motion according to the motion control instruction; the motion control module comprises a moving mechanism for driving the slide block (3) to move;

a positioning module: for emitting light, receiving light, and measuring an illuminance value of the received light; the positioning module is fixedly arranged on the sliding block (3) and comprises a light emitting unit and a light illuminance measuring unit; the positioning module is coupled with the computing module through an electric signal and sends the illumination value of the received light to the computing module in real time; the light emitting unit emits light with a certain thickness and parallel to a horizontal plane; the light receiving end of the light illuminance measuring unit is coaxial with the light emitted by the light emitting unit;

a calculation module: the illumination processing module is used for receiving the illumination value from the positioning module, carrying out average value calculation or integral calculation on the illumination value to obtain an illumination processing value and sending the illumination processing value to the master control module;

a height measurement module: the device is used for measuring the distance between the sliding block (3) and an artificial preset initial position to obtain a sliding block height value, and then sending the sliding block height value to the main control module.

2. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in claim 1, wherein: the support is a square upright post (1).

3. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in claim 1, wherein: the light emitting unit comprises a laser emitter (11), or a visible light generator, or a monochromatic light generator, or an infrared light generator, or a near-ultraviolet light generator.

4. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in claim 3, wherein: the light emission unit further comprises an emission slit (9) for filtering light emitted by the laser emitter (11); the emitting slit (9), the light emitting end of the laser emitter (11) and the light receiving end of the light illuminance measuring unit are coaxial and are horizontally equal in height.

5. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in claim 3, wherein: the light emitting unit further comprises a right-angle prism (21) for dividing the light emitted by the laser emitter (11) into two symmetrical light; two light rays split by the right-angle prism (21) are parallel to a horizontal plane and have the same height, and are coaxial with a light ray receiving end of the light ray illuminance measuring unit and have the same horizontal height.

6. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in any one of claims 1 to 5, wherein: the light illuminance measuring unit adopts an illuminance sensor (12) or an illuminometer (19).

7. A system for optically locating and measuring the level of a liquid in a transparent container as claimed in claim 3, wherein: the height measuring module comprises a grating ruler (14), or a capacitive grating ruler, or a magnetic grating ruler; the height measuring module is detachably connected with the square upright post (1), and the extending direction of the height measuring module is parallel to the extending direction of the square upright post (1); and the sliding part of the height measuring module is fixedly connected with the sliding block (3).

8. Method for optically locating and measuring the level of a liquid in a transparent container, using a system for optically locating and measuring the level of a liquid in a transparent container according to claim 7, characterized in that: comprises the following steps:

s100, adjusting the posture of the support module to enable the extending direction of the support to be parallel to the local gravity acceleration direction;

s200, placing a transparent container containing liquid with the height value of the sliding block to be measured on the upper surface of the base (2); then adjusting the posture of the transparent container to enable the height direction of the transparent container to be parallel to the local gravity acceleration direction;

s300, starting the light emitting unit, and then adjusting the initial position of the sliding block (3) to enable the upper surface of the emitted light to be coplanar with the manually preset initial position; the slider height value is then set to 0.

S400, driving the sliding block (3) to move upwards; in the moving process, the illumination value is continuously collected by the light illumination measuring unit and is sent to the calculating module; setting the time when the sliding block (3) starts to move as an initial time;

s500, performing average value calculation or integral calculation on the contrast values by using the calculation module to obtain the illumination processing values, and sending the illumination processing values to the master control module;

s600, judging the moving direction of the sliding block (3) at the next moment by utilizing the master control module according to the illumination processing value at the current moment and combining a manually preset processing mode;

s700, controlling the sliding block (3) to move correspondingly by using the motion control module according to the motion control instruction until the motion direction is 'stop', stopping the motion of the sliding block (3), and stopping the light illumination measuring unit from collecting an illumination value;

s800, measuring the distance between the sliding block (3) and the initial position by using the height measuring module to obtain a sliding block height value, and then sending the sliding block height value to the main control module;

s900, calculating to obtain the liquid level height value according to the slide block height value by using the main control module, and then outputting the liquid level height value; the liquid level height value is the final result of the method.

9. The method of optically locating and measuring the level of a liquid in a transparent container of claim 8, wherein: in S600, the determining of the moving direction of the slider (3) at the next time by using the master control module according to the illumination processing value at the current time and combining a manually preset processing mode specifically includes the following steps:

s610, judging whether the processing mode of the illumination processing value at the current moment is an average value mode or an integral mode, and according to the judgment result, performing the following operations:

if the processing mode at the current moment is the average value mode, executing Sa 620; if the current-time illumination processing value is the illumination integral value, Sb620 is executed;

sa620, utilizing the computing module to perform average value computation again on the illumination value at the current moment and all the illumination values collected from the initial moment to obtain an illumination average value at the current moment;

and Sa621, comparing the illumination value at the current moment with a manually preset illumination average lower limit threshold, and performing the following operations according to the comparison result:

if the illumination value at the current moment is greater than or equal to the illumination average lower limit threshold, setting the motion direction as 'stop'; then, S630 is performed;

otherwise, setting the motion direction to "move up"; then, S630 is performed;

performing integral calculation again on the illumination value at the current moment and all the illumination values collected from the initial moment by using the calculation module to obtain an illumination integral value at the current moment; then calculating the fluctuation amplitude of the illumination integral value;

and Sb621, comparing the fluctuation amplitude of the illumination integral value at the current moment with a manually preset verification amplitude, and performing the following operations according to the comparison result:

setting the movement direction to "stop" if the fluctuation amplitude of the illuminance integral value at the current time is greater than or equal to the approved amplitude; then, S630 is performed;

otherwise, setting the motion direction to "move up"; then, S630 is performed;

s630, packaging the motion direction into a motion control instruction and sending the motion control instruction to the motion control module; then S700 is performed.

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