Distance measurement method based on reflection object setting

Abstract

The invention relates to a distance measurement method based on reflection object setting, which is particularly suitable for measuring the distance from a top opening of a cave scene to the surface of a medium object (such as liquid media as water, oil and the like) below the top opening. The method is characterized in that a reflection object is arranged, and a plane block which is good in reflection property and large in area is arranged and can efficiently feed back sound waves, electromagnetic waves, infrared rays or lasers and the like emitted by the distance measuring device; a regular geometrical shape is provided, so that the volume and the height are convenient to calculate; the overall density of the reflecting object is smaller than the density of the medium object below, so that the reflecting object can float on the medium object conveniently. Then, an equipment base is fixed at the top opening of the cave scene, and a distance measuring device capable of emitting sound waves, electromagnetic waves, infrared rays or laser and the like, a traction device capable of stretching a reflecting object and the reflecting object connected by a rope are installed; during measurement, the reflection object is moved, and when it is monitored that the reflection object reaches the surface of the lower medium object, the distance from the top opening of the cave scene to the surface of the lower medium object can be obtained with high quality.

Description

Technical Field

[0001] This invention relates to the fields of industrial automation and process control technology, and specifically to a distance measurement method based on reflective surfaces, which is particularly suitable for measuring the distance from the top opening of a cave-like scene to the surface of a medium object below it. Background Technology

[0002] This invention relates to a distance measurement method based on reflective surfaces, which can be widely applied to the processing of level gauges or material level gauges in cave exploration and industrial automation. Level gauges or material level gauges are instruments that monitor and control the height (level) of liquids or particulate solids in cave-like environments such as containers or storage facilities by utilizing physical principles such as buoyancy, pressure difference, capacitance, ultrasound, and radar waves. They play an important role in many industries such as chemical, petroleum, water treatment, food processing, pharmaceutical, power, papermaking, metallurgy, shipbuilding, and boilers, ensuring the continuity, safety, and efficiency of production processes. Based on whether they come into contact with the measured medium, existing level gauges or material level gauges can be divided into contact type and non-contact type (Ma Ting. Research and Design of Capacitive Glass Tube Level Gauge [D]. Northwest Normal University, 2023. DOI:10.27410 / d.cnki.gxbfu.2023.000954.). Currently, significant progress has been made in the technical methods used for level gauges or material level gauges. However, shortcomings remain in areas such as high-precision measurement, ease of operation, stability, and applicability. Measurement under harsh environmental conditions and dynamic changes in the surface of the medium remains a particularly challenging problem. The relevant details are as follows:

[0003] ◆Contact level gauges or material level gauges are a type of measuring device that comes into direct contact with the medium being measured. They require...

[0004] The level gauges used are physical methods to detect and monitor the height of a medium or the interface position of a medium within a container. Most of these level gauges are traditional and simple in structure. Because they frequently come into contact with the medium being measured, their performance and lifespan are relatively poor, making them unsuitable for widespread use in environments with harsh measurement conditions such as high corrosion, high viscosity, and high temperature. Furthermore, these level gauges typically require on-site calibration, which is cumbersome and often introduces significant errors during measurement, sometimes failing to meet operational requirements (Ma Hongguang. Research and Implementation of Integrated Multifunctional Intelligent Level Gauge [D]. Shanghai University of Engineering Science, 2020. DOI:10.27715 / d.cnki.gshgj.2020.000158.). Common types of contact level gauges or material level gauges include: float type, servo type, capacitive type, magnetostrictive type, and differential pressure type (Ma Ting. Research and Design of Capacitive Glass Tube Level Gauge [D]. Northwest Normal University, 2023. DOI:10.27410 / d.cnki.gxbfu.2023.000954. / Ma Hongguang. Research and Implementation of Integrated Multifunctional Intelligent Level Gauge [D]. Shanghai University of Engineering Science, 2020. DOI:10.27715 / d.cnki.gshgj.2020.000158. / Liu Fenqiang. Research on Split-type Guided Wave Radar Level Gauge [D]. Chongqing University, 2022. DOI:10.27670 / d.cnki.gcqdu.2022.001291.). For example, the servo-type level gauge (Liu Fenqiang. Research on Split-Type Guided Wave Radar Level Gauge [D]. Chongqing University, 2022. DOI:10.27670 / d.cnki.gcqdu.2022.001291. /

[0005] Zhang Zhifeng. A brief analysis of the application of servo level gauges in ethylene and propylene spherical tanks [J]. Instrument and Meter User, 2021, 28(03): 110-112+25.), by controlling the float structure with a motor and measuring the stress on the structure, the liquid level is calculated in reverse by buoyancy. It can automatically monitor the changes in liquid level with high accuracy, and can achieve high accuracy and sensitivity through good control. However, the related control cost is high, making it difficult to apply to the dynamic changes of the medium. Maintenance is also difficult, and long-term mechanical friction wear will affect its measurement accuracy.

[0006] ◆Non-contact level gauges or material level gauges are a type of device that does not directly contact the measured medium during the measurement process. They use various non-immersion technologies, such as sound waves, ultrasonic waves, lasers, and radar, to detect and monitor the height of the medium or the interface position of the medium in a container. These level gauges or material level gauges provide an efficient and reliable method for measuring liquid or material levels, and are particularly suitable for applications with high requirements for cleanliness and safety. They can achieve accurate measurement through advanced technology, and can perform measurements without interfering with liquid flow or contacting the liquid or object, thus effectively avoiding the problems of contamination and corrosion of measuring equipment. Common types of non-contact level gauges or material level gauges mainly include: ultrasonic, fiber optic, laser / microwave radar, and air-blowing type (Ma Ting. Research and Design of Capacitive Glass Tube Level Gauges [D]. Northwest Normal University, 2023. DOI:10.27410 / d.cnki.gxbfu.2023.000954. / common types of level gauges,). Different types of non-contact level gauges or material level gauges have their own advantages and disadvantages (the principles and advantages and disadvantages of various level gauges, http: / / news.eeworld.com.cn / Test_and_measurement / ic484293.html).

[0007] For example, ultrasonic level gauges (Ma Hongguang. Research and Implementation of Integrated Multifunctional Intelligent Level Gauge [D]).

[0008] Shanghai University of Engineering Science, 2020. DOI:10.27715 / d.cnki.gshgj.2020.000158). This research utilizes the high frequency, strong penetration, and good directionality of ultrasound to measure liquid level by measuring the time difference between the emission and reception of the ultrasonic wave. These methods offer advantages such as simple structure, convenient installation and maintenance, and suitability for use in low-temperature environments. However, because the propagation medium for ultrasound is air, they cannot be applied to environments such as vacuum, environments where the measured medium absorbs waves, or environments containing floating or sinking particles. Furthermore, structural characteristics also affect measurement accuracy. The measurement principle of microwave radar level gauge (Ma Hongguang. Research and Implementation of Integrated Multifunctional Intelligent Level Gauge [D]. Shanghai University of Engineering Science, 2020.DOI:10.27715 / d.cnki.gshgj.2020.000158 / Peng Ning. Measurement Principle, Classification and Application of Radar Level Gauge [J]. China Instrument and Control, 2022, (11):57-60) is similar to that of ultrasonic level gauge, which measures the liquid level by detecting the time difference between transmitting and receiving electromagnetic waves. Microwave radar level gauge has the advantages of easy operation, stability and high accuracy, and can be used in a vacuum environment. However, it is limited by the dielectric constant of the medium, and the measurement results are poor in low temperature environment. In addition, it has a complex structure and high cost. The lidar level gauge (Ma Ting. Research and Design of Capacitive Glass Tube Level Gauge [D]. Northwest Normal University, 2023. DOI:10.27410 / d.cnki.gxbfu.2023.000954.) is similar in principle to the two non-contact level gauges mentioned above, featuring high precision, long measurement distance, and strong adaptability. However, it is easily affected by weather conditions such as heavy rain, dense smoke, and dense fog, which can affect its propagation distance and accuracy. The fiber optic level gauge (Liu Fenqiang. Research on Split-Type Guided Wave Radar Level Gauge [D]. Chongqing University, 2022. DOI:10.27670 / d.cnki.gcqdu.2022.001291.) measures liquid level using optical principles. When the emitted light source reaches the surface of the liquid being measured through an optical fiber, it is reflected and projected. The reflected light is received by the optical fiber and returned to the photoelectric device. The liquid level height is measured by detecting the amount of reflected light. Fiber optic level gauges have advantages such as strong applicability and real-time accuracy, but their measurement performance is poor in low-temperature environments, and they are expensive and not very practical. Air-blowing level gauges (Ma Hongguang. Research and Implementation of Integrated Multifunctional Intelligent Level Gauge [D]. Shanghai University of Engineering Science, 2020. DOI:10.27715 / d.cnki.gshgj.2020.000158. / Feng Cui. Development and Application of Intelligent Air-blowing Level Gauge [J]. Fluid Measurement and Control, 2023, 4(05):7-10) achieve accurate measurement of liquid level through the combination of air-blowing pipes and static pressure pipes.These instruments are particularly suitable for measuring the level of corrosive, easily crystallizing, highly viscous, molten, easily precipitating, solid-particle-containing, and high-temperature liquids. However, their air-blowing devices mainly consist of an air source, air-blowing pipe, flow stabilizing valve, flow meter, and pressure transmitter. The structure involves many parts, requiring significant assembly work, making maintenance difficult and the entire measurement process cumbersome. Generally, non-contact level gauges or material level gauges require feedback information to measure the liquid / material interface position. However, in some cases, such as when the medium absorbs light, waves, or infrared radiation emitted by the ranging device (in high-temperature environments), feedback information is difficult to obtain effectively, making it difficult for these level gauges or material level gauges to perform accurate measurements, such as measuring the distance from the top of a cave-like structure to the surface of the medium below.

[0009] To effectively address the problems of poor ranging accuracy, high equipment cost, and limited application scenarios associated with existing level gauges or material level gauges when the feedback characteristics of the medium are unfavorable, this invention proposes a distance measurement method based on a reflector, particularly suitable for measuring the distance from the top of a cave-like environment to the surface of a medium below. The method first fixes a base at the top of the cave and installs a ranging device based on sound waves, electromagnetic waves, infrared light, or laser light, a traction device for a stretchable reflector, and a reflector with good reflective properties connected by a rope. Then, the reflector is lowered to the surface of the medium using the traction device, allowing the ranging device to obtain high-quality feedback information, thereby obtaining the distance from the top of the cave to the surface of the medium below with high accuracy. Due to the reflector, the method of this invention enables the high-quality acquisition of the feedback information required by the ranging device, improving the detection effectiveness in such environments. Furthermore, it is simple to operate and has excellent application prospects. Summary of the Invention

[0010] To address the aforementioned technical problems, this invention provides a measurement method based on reflective surfaces, which is particularly suitable for measuring the distance from the top of a cave-like scene to the surface of a medium object below it.

[0011] The technical solution of this invention is: a distance measurement method based on a reflector, characterized by comprising the following steps:

[0012] Step 1: Fix a device base at the top of the cave-like scene. Install the following on the base: a ranging device based on sound waves, electromagnetic waves, infrared rays or lasers, a traction device that can stretch a reflector, and a reflector connected by a rope. The reflector facing the ranging device is a large flat block with good reflective properties.

[0013] Step 2: Based on the above traction device, the reflector is continuously moved down until it is detected that the reflector has landed on the surface of the medium object and no longer descends. At this time, the distance measured by the ranging device no longer increases.

[0014] Step 3: When the reflector stops descending, a high-precision distance from the top of the reflector can be obtained using a ranging device based on sound waves, electromagnetic waves, infrared rays, or lasers.

[0015] Step 4: Based on the weight and geometry of the reflector, and by comparing it with the density of the medium, the height to which the reflector is immersed in the medium can be calculated. Since the height of the reflector is known, the distance obtained in Step 3 can be added to the height of the reflector and subtracted from the height of its immersion in the medium to obtain the precise distance from the top opening to the surface of the medium below it.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention discloses a distance measurement method based on a reflector, particularly suitable for measuring the distance from the top of a cave-like structure to the surface of a lower medium. The method utilizes a traction device to lower a reflector to the surface of the medium, allowing distance measuring devices using sound waves, electromagnetic waves, infrared light, or lasers to obtain high-quality feedback information. This enables high-precision measurement of the distance from the top of the cave to the surface of the lower medium. Because this invention efficiently reflects sound waves, electromagnetic waves, infrared light, or lasers using a reflector, and calculates the height of the reflector's immersion in the medium based on its weight and geometry, it can obtain a high-precision distance from the top of the cave to the surface of the lower medium. Compared to existing level gauges or material level gauges, this invention provides a convenient and reliable method for obtaining high-precision distances from the top of the cave to the surface of the lower medium, thus improving the efficiency of related work. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a distance measurement method based on reflective material in an embodiment of the present invention, which measures the distance from the top opening of a cave-like scene to the surface of a medium object below it.

[0019] Figure 2 This is a schematic diagram of the TOF ranging principle in an embodiment of the present invention. Detailed Implementation

[0020] This invention provides a distance measurement method based on reflective surfaces, particularly suitable for measuring the distance from the top of a cave-like scene to the surface of a medium below it. Based on the principles of distance measurement using sound waves, electromagnetic waves, infrared rays, or lasers, this invention utilizes reflective surfaces to reflect these signals, improving the effectiveness of information feedback and enabling high-precision measurement of the distance from the top of a cave-like scene to the surface of a medium below it.

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0022] Example 1

[0023] like Figure 1 As shown in the figure, an embodiment of the present invention provides a distance measurement method based on a reflector setup for measuring the distance from the top opening of a cave-like scene to the surface of a medium object below it, comprising the following steps:

[0024] Step S1: Fix a device base at the top of the cave-like scene, on which are installed: a ranging device based on sound waves, electromagnetic waves, infrared rays or lasers, a traction device for a stretchable reflector, and a reflector connected by a rope (the reflector is a large flat block with good reflective properties facing the ranging device, and the reflector has a relatively regular geometric shape, which is convenient for calculating its volume and height).

[0025] Step S2: Based on the above-mentioned traction device, the reflector is continuously moved down until it is detected that the reflector has landed on the surface of the medium object and no longer descends. At this time, the distance measured by the ranging device no longer increases.

[0026] Step S3: When the reflector stops descending, a high-precision distance from the top of the reflector can be obtained using a ranging device based on sound waves, electromagnetic waves, infrared rays, or lasers.

[0027] Step S4: Based on the weight and geometry of the reflector, and by comparing it with the density of the medium, the height of the reflector immersed in the medium can be calculated. Since the height of the reflector is known, the high-precision distance from the top opening to the surface of the medium below can be obtained by adding the height of the reflector to the distance obtained in step S3 and subtracting the height of the reflector from the height of the medium.

[0028] Step S5: When the reflector is detected to be floating on the surface of the medium, the rope stops descending. While the surface of the medium is dynamically rising, the rope is tightened periodically to prevent it from falling into the medium and to keep the reflector floating on its surface, thus maintaining its position within the observation range of the ranging device. Conversely, when the surface of the medium is dynamically falling, the traction rope is loosened in a timely manner to allow the reflector to fall onto the surface.

[0029] In one embodiment, step S2 above: based on the above-mentioned traction device, the reflector is continuously moved down until it is detected that the reflector has fallen on the surface of the medium object and no longer descends. At this time, the distance measured by the ranging device no longer increases.

[0030] In this embodiment of the invention, the traction device controls the downward movement of the reflector. During the process before reaching the surface of the underlying medium, the distance measured by the ranging device gradually increases with the descent time. When the reflector lands on the surface of the underlying medium, the distance measured by the ranging device no longer increases with time. Therefore, it can be determined that the reflector has reached the surface of the underlying medium.

[0031] In one embodiment, step S3 above: when the reflector no longer descends, a high-precision distance from the top opening to the reflector can be obtained using a ranging device based on sound waves, electromagnetic waves, infrared rays, or lasers.

[0032] This invention utilizes ranging principles from sound waves, electromagnetic waves, infrared radiation, and lasers to accurately measure the distance from the top of the surface to the reflector. This invention uses a lidar system as an example to illustrate the principle, specifically the TOF (Time of Fly) ranging method. Figure 2 As shown. The core principle of Time-of-Flight (TOF) is to use a laser to shoot a very short laser beam at the object being detected, and a timer records the time of emission. The time of return of the light is then recorded by a receiver. Finally, by directly measuring the time it takes for the laser to be emitted, hit the object, and return to the detector, the difference between these two times yields the "time of flight" of the light. Since the speed of light is constant, the distance from the detector to the object can be calculated once the relevant speed and time of flight are known.

[0033] In one embodiment, step S4 above: based on the weight and geometry of the reflector and by comparing it with the density of the medium object, the height of the reflector immersed in the medium object can be calculated. Since the height of the reflector is known, the high-precision distance from the top opening to the surface of the medium object below it can be obtained by adding the distance obtained in step S3 to the height of the reflector and subtracting the height of the reflector immersed in the medium object.

[0034] This invention employs Archimedes' principle to calculate the height of the reflector immersed in the medium. Archimedes' principle states that any object fully or partially submerged in a liquid experiences an upward buoyant force equal to the weight of the volume of liquid displaced by the object. Therefore, based on the density of the medium, the weight of the reflector, and its geometry, the height of the reflector immersed in the medium can be determined.

[0035] In one embodiment, step S5 above—when the reflector is detected to be floating on the surface of the medium object—stops the rope from descending. During the dynamic rise of the medium object's surface, the rope is tightened upwards periodically to prevent it from falling into the medium object and to ensure the reflector remains floating on top, keeping it within the observable range of the ranging device. Conversely, when the medium object's surface dynamically descends, the traction rope is loosened in a timely manner to allow the reflector to fall onto the surface.

[0036] In this embodiment of the invention, the measurement distance of the rising surface of the medium object is periodically monitored over time. Based on this change, the distance from the reflective surface of the reflector to the surface of the medium object, and the height the surface of the medium object rises, is compared to calculate the length of the rope that will allow it to tighten upwards without pulling the reflector away from the surface of the medium object. The rope is then tightened according to this length. When the surface of the medium object dynamically descends, the traction rope is loosened in a timely manner to allow the reflector to fall back onto the surface of the medium object.

[0037] The parts of this invention not described in detail are well-known in the field.

[0038] The above description is only a partial embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention, such as: detection and processing of reflective material reaching the surface of a medium object, processing of detecting the relevant height after reflective material floats to a certain position, and pulling reflective material up to the top of a hole in the form of a balloon to measure the height from the bottom of the hole to the top of the hole, etc.

Claims

1. A method for measuring the distance based on the setting of a retroreflector, especially suitable for measuring the distance from the mouth of a cave-like scene to the water surface, characterized in that, The method comprises the following steps: 1.1 Fix a device base on the top opening, on which install a ranging device based on sound wave, electromagnetic wave or laser, a pulling device for the reflector, and a reflector with good reflecting property connected by a rope; 1.2 Continuously lower the reflector based on the pulling device until the reflector stops falling on the liquid surface, and the distance measured by the ranging device no longer increases, thus the distance from the top opening to the liquid surface is obtained.

2. The reflector used in step 1.1 of claim 1, wherein: 2.1 The reflecting surface of the object facing the top opening is a large-area flat block with good reflecting property, so that the sound wave, electromagnetic wave or laser emitted by the ranging device can be well returned to perform high-precision ranging; 2.2 The reflector is composed of a low-density solid material (such as foam) at the bottom and a material with good reflecting property at the top, so that its density is less than that of the liquid in the cave scene, and it can float on the liquid surface; 2.3 The object has a regular geometric shape, which is convenient for calculating its volume and height, and the rope is fixed at the center point, so that the reflecting surface of the reflector can be well balanced and perpendicular to the pulling rope when it is lowered.

3. The ranging process during the lowering of the reflector in step 1.2 of claim 1, wherein: 3.1 When the measured distance gradually increases over time during the lowering process, continue to lower; 3.2 When the measured distance does not increase over time during the lowering process, it indicates that the reflector has floated on the liquid surface, and the distance from the top opening to the liquid surface can be obtained according to the distance measured by the ranging device and the distance from the reflecting surface of the reflector to the liquid surface when it floats on the liquid surface; 3.3 When it is detected that the reflector has floated on the liquid surface, the rope no longer continues to lower, and when processing the dynamic rise of the liquid surface, the rope is tightened upward at intervals to prevent falling into the liquid and to prevent the reflector from drifting out of the observable area of the ranging device.

4. The method of claim 3, wherein the distance between the reflective surface of the reflector and the liquid surface is calculated when the reflector floats on the liquid surface. ： 4.1 According to the weight of the reflector and its geometric shape, and by comparing the density of the liquid, the height of the reflector immersed in the liquid can be calculated; 4.2 According to the height of the reflector, subtract the height of the reflector immersed in the liquid, and the distance from the reflecting surface of the reflector to the liquid surface when it floats on the liquid surface is obtained.

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