Intelligent monitoring system and method for dust collector ash hopper ash level based on multi-point laser ranging

Abstract

The present invention discloses a dust collector ash hopper ash level intelligent monitoring method based on multi-dot laser ranging, mainly including a multi-dot laser ranging sensor, an equipment control box, a cloud platform and a networking terminal, wherein the multi-dot laser ranging sensor is arranged at the middle position just above the ash hopper, and the networking terminal is installed with user software and software matching the multi-dot laser ranging sensor, wherein the user software is used to optimize the ranging data received from the multi-dot laser ranging sensor to obtain a morphology cloud map of the current material level surface, and dynamically display it on the terminal display screen in real time, and the user determines whether there is hanging material on the ash hopper wall and determines whether the current material level surface is a conical material surface, or an uneven material surface or a flat material surface according to the morphology cloud map of the material level surface, and obtains the current material level height. The method can accurately identify the material level distribution and the hanging material on the ash hopper wall, and prevent false alarms due to false material levels.

Description

Technical Field

[0001] The invention relates to the technical field of dust collectors, and in particular to a system for monitoring the ash level in an ash hopper of a dust collector. Background Art

[0002] In industrial production processes, dust collectors are widely used to capture and filter particulate matter in the air to ensure a clean environment and a safe workplace. However, after long-term use, the hopper of the dust collector may accumulate a lot of dust, reducing its performance and increasing maintenance costs. Emergency unloading of the hopper will also cause serious environmental pollution in the factory and cause adverse effects. Therefore, the normal and safe operation of the dust removal system is a prerequisite for ensuring the dust removal effect. In order to prevent the dust collector hopper from causing system failures due to material level problems, or even the collapse of the dust collector, it is extremely important to monitor the material level of the dust collector hopper in real time to ensure the normal operation of the dust collector. Under different conditions, various level measurement technologies are used to measure the level of bulk solids in silos, hoppers / silos, such as level measurement based on weighing sensors, ultrasonic sensors, laser sensors and guided wave radar sensors. [1] Contact and non-contact measurement (such as non-contact measurement such as laser sensors, ultrasonic sensors and radar sensors, and contact measurement such as capacitive sensors) can continuously measure the level, which provides convenience for real-time monitoring of the level. [2] .

[0003] The current dust collector system usually relies on regular maintenance plans and cannot monitor the changes in the ash level of the ash hopper in real time. Most users' ash hoppers mainly use level meters based on the following principles: capacitive level meter, radio frequency admittance level meter, ultrasonic level meter, radar level meter, etc. However, each level meter based on different principles has its limitations and is affected by various external factors. Among them, the radar level meter, the dust adhering to the antenna will affect the transmission and reception effect of the antenna, resulting in signal attenuation and affecting the accuracy of the level measurement. Therefore, radar level meters are not suitable for places with high dust concentrations. Ultrasonic level meters are not suitable for places where a high concentration of dust is easily generated in the space. Highly concentrated dust will reflect ultrasonic waves, but due to the unclear reflection surface and the reflection position may not be the surface of the material, it is easy to cause false indications. At the same time, dust accumulates on the transmitting surface of the probe, which will hinder the transmission and reception of ultrasonic waves. Capacitive level meters and radio frequency admittance level meters are taboo to humid environments. Water vapor in a humid environment will change the capacitance value of the capacitive level meter, resulting in measurement value deviation. For RF admittance level meters, water vapor in a humid environment will absorb and attenuate RF signals, causing attenuation of signal transmission and affecting the measurement accuracy and stability of the level meter. Although laser ranging has the characteristics of low energy consumption, concentrated energy, small divergence angle, dust penetration, and non-contact measurement, its single-point ranging method cannot accurately judge the material surface condition, and the measured material level may not be the actual material level. [3] At present, a new type of material level meter has appeared on the market - 3D ultrasonic material level meter, which can simulate the 3D imaging effect of the silo and calculate the storage capacity of the silo. However, when the material adheres to the silo wall, a "false material level" will appear, causing system failure. [4] .

[0004] For the dust collector system, if the ash hopper level meter cannot accurately judge the height of the ash in the ash hopper and issue a warning in time to discharge the ash, it may also cause a major safety accident such as the collapse of the ash hopper. At the same time, the surface shape of the ash hopper material plays an important role in the normal operation of the ash hopper unloading work. However, since the internal situation of the ash hopper is invisible to the human eye, the staff has no idea about the surface shape of the material, which is very likely to cause an unloading accident.

[0005] [References]

[0006] [1]LEWIS SR J D.Technology Review Level Measurement of Bulk Solids inBins,Silos and Hoppers[J].2004Monitor Technologies LLC,2004.

[0007] [2]MOHINDRU P.Development of liquid level measurement technology:Areview[J / OL].Flow Measurement and Instrumentation,2023,89:102295.DOI:10.1016 / j.flowmeasinst.2022.102295.

[0008] [3] Lu Jun. Application of laser level meter in raw coal bunker level detection in thermal power plant[J]. Forestry Science and Technology Information, 2010, 42(4): 56-57.

[0009] [4] Su Xiaofeng. Optimization of monitoring device for calcium carbide silo[J]. Polyvinyl Chloride, 2023, 51(8): 26-29, 32. Summary of the invention

[0010] In view of the above-mentioned prior art, considering that the existing level meters cannot accurately determine the height of the ash level in the ash hopper, cannot issue timely warnings, and cannot display the material surface of the ash hopper, the present invention proposes an intelligent monitoring method for the ash level of the dust collector hopper based on the principle of laser ranging. This method utilizes multi-point laser ranging, which not only has the advantages of laser ranging, but also solves the problem of "false material level" that occurs when materials adhere to the wall of the ash hopper by optimizing the algorithm of the measured data, and overcomes the shortcomings of the traditional laser level meter that single-point ranging cannot accurately determine the material surface conditions, so that the ash level of the ash hopper can be accurately determined; and the material surface is modeled and displayed, and finally the material surface morphology and material level information are obtained, so that the staff can immediately understand the material surface morphology. In the real-time monitoring process, when the ash in the ash hopper reaches a certain position, an alarm can be issued in time to ensure that the amount of ash in the ash hopper is at a normal level.

[0011] In order to solve the above technical problems, the present invention proposes an intelligent monitoring system for ash level in dust collector hopper based on multi-dot laser ranging, which includes a multi-dot laser ranging sensor, an equipment control box, a cloud platform and an Internet terminal; the equipment control box is provided with a power adapter, a 4G signal transmission module and an MCU module, the power adapter converts the external 220V AC power into 5V DC power to power the MCU module and the 4G signal transmission module respectively; the MCU module is connected to the 4G signal transmission module through a signal converter; the four pins of the multi-dot laser ranging sensor are connected to the MCU module through an aviation cable The MCU module is used to read the distance measurement data transmitted by the multi-point array laser ranging sensor, and the MCU module is connected to the 4G signal transmission module through a signal converter; the signal converter converts the data of the MCU module into data that can be parsed by the 4G signal transmission module, and uploads the collected distance measurement data to the cloud platform. The networked terminal reads the distance measurement data of the multi-point array laser ranging sensor on the cloud platform, and the networked terminal processes the received distance measurement data to obtain the gray level data of each point, and after processing, the current material level surface morphology is dynamically presented in real time in a visual form on the terminal display screen.

[0012] Furthermore, the dust collector ash hopper ash level intelligent monitoring system of the present invention comprises:

[0013] The VCC pin and GND pin of the multi-dot laser ranging sensor are connected to the corresponding interface on the MCU module using DuPont wires, the RXD of the multi-dot laser ranging sensor is connected to the TXD of the MCU module, and the TXD of the multi-dot laser ranging sensor is connected to the RXD of the MCU module to achieve data communication.

[0014] The multi-point array laser ranging sensors in this monitoring system adopt multiple cascades.

[0015] The monitoring system also includes an alarm device connected to the networking terminal.

[0016] At the same time, the present invention also proposes a method for detection using a monitoring system. The multi-dot laser ranging sensor is TOFSense-M, which uses 8×8 laser dot matrix measurement. The networked terminal is installed with user software and NAssistant software that matches the multi-dot laser ranging sensor. The user software is used to convert the received ranging data of the multi-dot laser ranging sensor into a morphological cloud map of the current material level surface, and display it in real time on the terminal display screen. The user determines whether there is hanging material on the hopper wall and determines whether the current material level surface is a conical material surface, an uneven material surface, or a flat material surface based on the morphological cloud map of the material level surface, and obtains the current material level height. The specific steps are as follows:

[0017] Step 1) using the low material level value measured by the multi-point laser ranging sensor as the initial value A; and setting the measurement error threshold to ΔA;

[0018] Step 2) If the current distance measurement data value is A1, and |A1-A|>△A, execute step 3), otherwise, discard this distance measurement value and execute step 3);

[0019] Step 3) making a material level surface morphology cloud map according to the distance measurement value;

[0020] Step 4) judging whether there is material hanging on the side wall of the ash hopper and the shape of the current material level surface according to the cloud map, and determining the height of the current material level, including:

[0021] 4-1) If the material level surface morphology cloud map is composed of one area, it is considered that there is no hanging material on the ash hopper side wall, and step 4-2) is executed; if the material level surface morphology cloud map includes multiple independent areas, and the areas of the multiple areas are different in size, it is considered that there is hanging material on the ash hopper side wall corresponding to the small area, and step 4-2) is executed only for the morphology cloud map corresponding to the large area;

[0022] 4-2) If the brightness scale of the morphology cloud map determines that the material surface is one of the following: conical material surface, uneven material surface, or flat material surface;

[0023] 4-3) Get the current material level, including:

[0024] For a flat material surface, the material level average of the material level surface morphology cloud map is taken as the current material level height;

[0025] For uneven material surface, the maximum value of all peak values ​​of the material level surface morphology cloud map is taken as the current material level height;

[0026] For a conical material surface, the peak value of the material level surface morphology cloud map is taken as the current material level height.

[0027] Furthermore, in step 1) of the monitoring method, the method for determining the measurement error threshold △A is: after turning on the multi-point array laser ranging sensor for 2 minutes, start recording the ranging data, and measure for 10 seconds under the same working conditions, take the average value of 100 data values, and the maximum absolute value of the difference between the 100 data values ​​and the average value is the measurement error threshold △A.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In order to verify the effectiveness of the method of the present invention, a verification experiment was conducted using a physical hopper model to test different material surface morphologies, material levels, and material hanging on the hopper wall. The results show that the method of the present invention can accurately identify material level distribution and material hanging on the hopper wall, and prevent false alarms due to "false material levels".

[0030] The present invention realizes real-time intelligent monitoring, can monitor the ash level of the ash hopper in real time, and provide material surface morphology instantly, so that the staff can understand the height of the ash level and the material surface morphology of the ash hopper at any time. When the ash level of the ash hopper is abnormal, it can accurately locate the position and remind the staff to go for local maintenance, thus saving a lot of manpower and material resources, and it is economical, practical and stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a model diagram of the dust level monitoring scenario of the dust collector hopper in the present invention;

[0032] Figure 2 A schematic diagram of a system for implementing the monitoring method of the present invention;

[0033] Figure 3 This is a flow chart of the monitoring method of the present invention;

[0034] Figure 4 The photos of the actual conical material surface and the corresponding material surface morphology cloud map, where (a) is the photo of the actual conical material surface, and (b) is the corresponding conical material surface morphology cloud map;

[0035] Figure 5 The actual uneven material surface photo and the corresponding material surface morphology cloud map, where (a) is the actual uneven material surface photo, and (b) is the corresponding uneven material surface morphology cloud map;

[0036] Figure 6 The actual flat material surface photo and the corresponding material surface morphology cloud map, where (a) is the actual flat material surface photo, and (b) is the corresponding flat material surface morphology cloud map;

[0037] Figure 7 Comparison between the different material surface morphology cloud images obtained in the experimental example and the actual material surface measurement height, where 0 represents a conical material surface, 1 represents an uneven material surface, and 2 represents a flat material surface;

[0038] Figure 8 This is the morphology cloud diagram of the conical material surface with hanging material obtained in the experimental example;

[0039] Fig. 9 This is the cloud diagram of the uneven material surface with hanging material obtained in the experimental example;

[0040] Fig.10 This is a cloud diagram of the flat material surface with hanging materials obtained in the experimental example.

[0041] In the figure:

[0042] 1- Bracket 2- Ash hopper 3- Equipment control box

[0043] 4-Supporting platform 5-Aviation cable 6-Multi-point laser ranging sensor

[0044] 7- Dust cover 8- 4G signal transmission module 9- Power adapter

[0045] 10-MCU module 11-communication data converter 12-network terminal

[0046] 13-Cloud Platform DETAILED DESCRIPTION

[0047] The design concept of the intelligent ash hopper ash level monitoring method for the dust collector of the present invention is: the ash hopper level meters currently used have various problems. Laser ranging technology has the characteristics of concentrated energy, small divergence angle, and can penetrate dust. Based on the principle of multi-lattice laser ranging, the lattice laser ranging is used to optimize the measured data by algorithm, and the material surface is modeled and displayed, and finally the material surface morphology and material level information are obtained. The physical model of the ash hopper is used to verify the different material surface morphologies, material levels and material hanging conditions on the ash hopper wall. The method of the present invention is verified to be able to accurately identify the material level distribution and the material hanging on the ash hopper wall, and prevent false alarms due to the occurrence of "false material levels". The monitoring method of the present invention uses wireless transmission to send data to the networked terminal, and the operator can understand the ash level of the hopper and the material surface morphology in real time. If an abnormality occurs, the operator can quickly locate and repair it, saving a lot of manpower and material resources.

[0048] The present invention is further described in detail below in conjunction with the accompanying drawings and experimental examples. It is to be understood that the specific experimental examples described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0049] Experimental example

[0050] by Figure 1 Taking the square ash hopper model as an example, the upper side length of the ash hopper 2 is 30 cm, the lower side length is 15 cm, and the overall height is 40 cm. The material used in the experiment is first-class fly ash, which is collected from the flue gas after coal combustion in coal-fired power plants.

[0051] The ash hopper 2 is supported on a bracket 1 , and a supporting frame 4 is provided on the top of the frame 1 . The monitoring system of the present invention includes a multi-dot array laser ranging sensor 6 and an equipment control box 3 arranged on the supporting frame 4 .

[0052] like Figure 1 and Figure 2As shown, the device control box 3 is provided with a power adapter 9, a 4G signal transmission module 8 and an MCU module 10, the power adapter 9 converts the external 220V mains into 5V DC power to power the MCU module 10 and the 4G signal transmission module 8 respectively; the MCU module is connected to the 4G signal transmission module 8 through a signal converter 11; the four pins of the multi-dot laser ranging sensor 6 are connected to the MCU module 10 through an aviation cable 5; the MCU module is used to read the ranging data transmitted by the multi-dot laser ranging sensor 6, specifically, the VCC pin and the GND pin of the multi-dot laser ranging sensor 6 are connected to the corresponding interface on the MCU module 10 using a DuPont line, the RXD of the multi-dot laser ranging sensor 6 is connected to the TXD of the MCU module 10, and the TXD of the multi-dot laser ranging sensor 6 is connected to the RXD of the MCU module 10 to realize data communication.

[0053] The MCU module 10 is connected to the 4G signal transmission module 8 through a signal converter 11; the signal converter 11 converts the data of the MCU module 10 into data that can be parsed by the 4G signal transmission module 8, and uploads the collected distance measurement data to the cloud platform 13. The network terminal 12 is installed with user software and NAssistant software matching the multi-dot laser distance measurement sensor 6, and the network terminal 12 reads the distance measurement data of the multi-dot laser distance measurement sensor 6 on the cloud platform 13. The user software is used to process the distance measurement data received from the multi-dot laser distance measurement sensor 6 to obtain the material level height data of each point, further convert it into a morphological cloud map of the current material level surface, and display it in real time on the terminal display screen in a visual form. The user determines whether there is hanging material on the hopper wall and determines whether the current material level surface is a conical material surface, an uneven material surface or a flat material surface based on the morphological cloud map of the material level surface, and obtains the current material level height. In the present invention, the networked terminal is equipped with an alarm system. When the ash level reaches a high level, the terminal will send an alarm signal to remind the staff to unload the ash in time; when the ash level reaches a low level during unloading, the terminal will also send an alarm signal to remind the staff to stop unloading. At the same time, the ash hopper material surface morphology is presented in real time through the host computer, providing the staff with the material surface status immediately.

[0054] The main idea of ​​the monitoring method of the present invention is to use the data of low material level as the initial value. When the material level increases, the distance value of the material surface will decrease, while the distance value from the laser point to the hopper wall will remain unchanged. Subtract the initial value from the measured data value. If the absolute value of the difference is greater than the set threshold, the data value is retained, otherwise the value is discarded. The remaining data is arranged in a dot matrix according to the position, thereby presenting the material surface morphology. According to the different material surface morphologies, the material level height is finally determined. The method flow is as follows Figure 3 The specific contents include:

[0055] Step 1) The low material level value measured by the multi-point array laser ranging sensor 6 is used as the initial value A; and the measurement error threshold is set to △A. In the present invention, it is taken into account that during laser ranging, the measurement data will fluctuate to a certain extent, and the fluctuation range is ±1cm. Therefore, the measured data is optimized by setting a measurement error threshold in the present invention. The setting method of the measurement error threshold △A is: after turning on the multi-point array laser ranging sensor 6 for 2 minutes (mainly because the sensor needs preheating time to allow its electronic components to reach a stable state), start recording the ranging data, and measure for 10s under the same working conditions, take 100 data values ​​to calculate the average value, and the difference between the 100 data and the average value is ±1cm, and △A=1cm is taken. In this experimental example, the measurement error threshold △A is 1cm.

[0056] Step 2) If the current distance measurement data value is A1, and |A1-A|>△A, execute step 3), otherwise, discard this distance measurement value and execute step 3);

[0057] Step 3) making a material level surface morphology cloud map according to the distance measurement value;

[0058] Step 4) judging whether there is material hanging on the side wall of the ash hopper and the shape of the current material level surface according to the cloud map, and determining the height of the current material level, including:

[0059] 4-1) If the material level surface morphology cloud map is composed of one area, it is considered that there is no hanging material on the ash hopper side wall, and step 4-2) is executed; if the material level surface morphology cloud map includes multiple independent areas, and the areas of the multiple areas are different in size, it is considered that there is hanging material on the ash hopper side wall corresponding to the small area, and step 4-2) is executed only for the morphology cloud map corresponding to the large area;

[0060] 4-2) If the brightness scale of the morphology cloud map determines that the material surface is one of the following: conical material surface, uneven material surface, or flat material surface;

[0061] 4-3) Obtain the current material level, including:

[0062] For a flat material surface, the material level average of the material level surface morphology cloud map is taken as the current material level height;

[0063] For uneven material surface, the maximum value of all peak values ​​of the material level surface morphology cloud map is taken as the current material level height;

[0064] For a conical material surface, the peak value of the material level surface morphology cloud map is taken as the current material level height.

[0065] Considering that the measured data will fluctuate to a certain extent during laser ranging, the fluctuation range is ±1 cm. Therefore, the measured data is optimized by setting a measurement error threshold in the present invention. The setting method of the measurement error threshold ΔA is: after turning on the multi-point array laser ranging sensor 6 for 2 minutes, start recording ranging data, and measure for 10 seconds under the same working condition, take 100 data to calculate the average value, and the difference between the 100 data and the average value is ±1 cm, and ΔA=1 cm is taken.

[0066] In the present invention, the multi-dot laser ranging sensor 6 adopts TOF Sense-M multi-dot laser ranging sensor. The sensor adopts 940nm near-infrared rays, and the field of view (FOV) parameters are 45° horizontally and vertically, and 63° diagonally. It has the characteristics of low power consumption and low cost. The ranging range is 0.015-4m, the ranging frequency is 60Hz, and the distance resolution is 1mm. The sensor adopts 8×8 laser dot matrix measurement. According to the size of the ash hopper 2, multiple multi-dot laser ranging sensors 6 can be cascaded for use.

[0067] In the hopper 2 of the bag filter, the fly ash will be concentrated to the bottom of the hopper due to gravity, forming a conical material surface. This shape helps to concentrate and unload the fly ash smoothly, and is the most typical shape of the hopper material surface. If the hopper and ash unloading system are properly designed, and the operation and maintenance are proper, a flat material surface will also appear. When the fly ash contains larger particles or has high humidity, uneven material surface or lumps may appear, affecting the fluidity of the fly ash and the unloading efficiency of the hopper. If the fly ash has high humidity and strong adhesion, it will adhere to the wall of the hopper, and hanging material may also occur. The test conditions are shown in Table 1.

[0068] Two working conditions are designed in this experimental example, namely working condition 1 and working condition 2, as shown in Table 1. The specific implementation steps are as follows:

[0069] Working condition 1:

[0070] In the first step, the bottom of the ash hopper is sealed with an iron plate to simulate the empty state of the ash hopper;

[0071] The second step is to add materials to make the material level reach the manually set low material level value of 5cm;

[0072] The third step is to place the dot matrix laser sensor in the middle position just above the ash hopper;

[0073] The fourth step is to add materials so that the material surface is in a common cone shape;

[0074] Step 5: Turn on the dot matrix laser sensor for real-time monitoring. After waiting for 2 minutes, turn on data recording, record the measurement values ​​of 64 points, export the data after recording for 10 seconds, and turn off data recording.

[0075] Repeat steps 4 and 5 to obtain point measurement data of different material surface shapes (uneven material surface or flat material surface).

[0076] Working condition 2: First, repeat the first, second, third and fourth steps of working condition 1;

[0077] The fifth step is to spray water mist on the dust to increase the humidity and make the dust adhere to the wall of the ash hopper to simulate the hanging material situation;

[0078] Step 6: Turn on the dot matrix laser sensor for real-time monitoring. After waiting for 2 minutes, turn on data recording, record the measurement values ​​of 64 points, export the data after recording for 10 seconds and turn off data recording.

[0079] Repeat steps 4, 5, and 6 to obtain the point measurement data of hanging materials under different material surface shapes.

[0080] Table 1 Experimental conditions

[0081] Working condition 1: different shapes Conical surface Uneven material surface Smooth material surface Working condition 2: different shapes and hanging materials Conical material surface + hanging material Uneven material surface + hanging material Smooth material surface + hanging material

[0082] (1) The traditional laser level meter adopts a single-point distance measurement method, which cannot accurately judge the material surface and is prone to misjudgment of the material level. The method described in the present invention is used to experimentally explore the common conical material surface, uneven material surface and flat material surface in the ash hopper. The conical material surface is a typical material surface of the ash hopper material. Figure 4 The middle cone material surface diagram is very close to the actual cone material surface, and the peak value is around 27.5cm. Figure 5 and Figure 6 The uneven material surface and the flat material surface are described. The two material surface diagrams are basically consistent with the actual material surface morphology. Figure 7 It can be seen that, under the conditions of uneven material surface and flat material surface, the material level value measured by the method is very close to the actual material level value, while for the conical material surface, the material level value measured by the method is somewhat different from the actual material level value, but is still within an acceptable range.

[0083] The above results show that the method uses a dot matrix laser sensor to measure different material surface morphologies, and its material level measurement and material surface presentation have high accuracy. For a conical material surface, its material level value is generally taken as the material level value at the highest point of the material surface, but due to the influence of the laser point density, it cannot be guaranteed that a laser point will fall exactly at the highest point of the material surface. Therefore, the strategy of using the peak material level value of the material surface to replace the actual highest point material level in this method actually has a certain error. For uneven material surfaces and flat material surfaces, the material level value of the entire material surface will not have an obvious peak value like the material level of the conical material surface, so the deviation between the material level measurement value and the actual material level value is small. This method overcomes the shortcomings of traditional single-point laser level meters that cannot accurately judge the material surface conditions. At the same time, it can make good use of the advantages of low energy consumption, small divergence angle, and high precision of laser ranging, accurately present the material surface morphology, provide material level information, and help staff to grasp abnormal material surface or material level information in a timely manner and take corresponding measures.

[0084] (2) For material surfaces with different morphologies, the method of the present invention was used to carry out a material hanging identification experiment to verify the effectiveness of the method. Figure 8 It can be seen that in the conical material surface diagram, there are small areas of material surface that are independent of the large area of ​​material surface. At the same time, the material level values ​​of these small areas of material surface are around 30.0cm, which is greater than the peak value of 27.5cm of the large area of ​​material surface. It can be judged that the small area of ​​material surface is actually the material hanging on the wall of the ash hopper. Fig. 9 and Fig.10 In the figure, there are small areas of uneven material surfaces and flat material surfaces, and the material level values ​​of these material surfaces are greater than those of large areas.

[0085] Through the above results, it can be verified that this method has a good recognition effect on the hanging material on the wall of the ash hopper, avoiding the staff from taking the material level value of the hanging material as the material level value, resulting in misjudgment, and solving the problem of false material level. Through the material surface diagram, the situation of hanging material on the wall of the ash hopper can be seen more intuitively. For the case of small hanging material size, since the laser points emitted by the dot matrix laser sensor do not cover the small hanging material, there may be a situation where it cannot be recognized, but this will not affect the material level measurement and material surface morphology display. The size of the ash hopper physical model used in this experiment is smaller than the actual ash hopper, so the measurement of the 8×8 dot matrix laser sensor is sufficient to achieve a better material surface morphology presentation. The actual ash hopper size is larger, and a larger dot matrix can be formed by cascading sensors to obtain more detailed material surface characteristics and material level data. This method adopts the idea of ​​taking the difference between the material surface measurement data and the initial value to eliminate the unchanged ash hopper wall distance measurement value, thereby realizing the separation of the actual material surface and hanging material, and then judging the situation of hanging material on the ash hopper wall. The method solves the problem of misjudgment of material level by 3D ultrasonic level meter due to material adhering to the wall.

[0086] In summary, the monitoring method of the present invention can effectively measure the material level of the dust collector hopper and display the material surface morphology, while solving the problem of false material level caused by material hanging on the hopper wall.

[0087] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many improvements and changes without departing from the purpose of the present invention, which are all within the protection of the present invention.

Claims

1. A dust collector ash hopper ash level intelligent monitoring system based on multi-point laser ranging, characterized in that: The monitoring system comprises a multi-point array laser ranging sensor (6), a device control box (3), a cloud platform (13) and a network terminal (12); The device control box (3) is provided with a power adapter (9), a 4G signal transmission module (8) and an MCU module (10); the power adapter (9) converts an external 220V mains electricity into 5V direct current electricity to supply power to the MCU module (10) and the 4G signal transmission module (8); the MCU module is connected to the 4G signal transmission module (8) via a signal converter (11); The four pins of the multi-point array laser ranging sensor (6) are connected to the MCU module (10) via an aviation cable (5); the MCU module is used to read the ranging data transmitted by the multi-point array laser ranging sensor (6); the MCU module is connected to the 4G signal transmission module (8) via a signal converter (11); the signal converter (11) converts the data of the MCU module (10) into data that can be parsed by the 4G signal transmission module (8), and uploads the collected ranging data to the cloud platform (13); the networked terminal (12) reads the ranging data of the multi-point array laser ranging sensor (6) on the cloud platform (13); the networked terminal (12) processes the received ranging data to obtain the gray level data of each point, and after processing, the current material level surface morphology is dynamically presented in a visual form on the terminal display screen in real time.

2. The dust collector ash hopper ash level intelligent monitoring system according to claim 1 is characterized in that: The VCC pin and the GND pin of the multi-dot laser distance measuring sensor (6) are connected to corresponding interfaces on the MCU module (10) using DuPont wires, the RXD of the multi-dot laser distance measuring sensor (6) is connected to the TXD of the MCU module (10), and the TXD of the multi-dot laser distance measuring sensor (6) is connected to the RXD of the MCU module (10), thereby realizing data communication.

3. The dust collector ash hopper ash level intelligent monitoring system according to claim 1 is characterized in that: The multi-point array laser distance measuring sensor (6) in the monitoring system adopts multiple cascades.

4. The dust collector ash hopper ash level intelligent monitoring system according to claim 1 is characterized in that: The monitoring system also includes an alarm device connected to the networking terminal (12).

5. A dust collector ash hopper ash level intelligent monitoring method based on multi-point laser ranging, characterized in that: A monitoring system as claimed in any one of claims 1 to 4 is used, wherein the multi-dot laser ranging sensor (6) is TOFSense-M, adopts 8×8 laser dot matrix measurement, and user software and NAssistant software matching the multi-dot laser ranging sensor (6) are installed on the network terminal (12), and the user software is used to convert the received ranging data of the multi-dot laser ranging sensor (6) into a morphological cloud map of the current material level surface, and display it in real time on the terminal display screen. The user determines whether there is hanging material on the hopper wall and determines whether the current material level surface is a conical material surface, an uneven material surface or a flat material surface based on the morphological cloud map of the material level surface, and obtains the current material level height; the specific steps of the monitoring method are as follows: Step 1) using the low material level value measured by the multi-dot laser ranging sensor (6) as the initial value A; and setting the measurement error threshold value to ΔA; Step 2) If the current distance measurement data value is A1, and |A1-A|>△A, execute step 3); otherwise, discard this distance measurement value and execute step 3); Step 3) making a material level surface morphology cloud map according to the distance measurement value; Step 4) judging whether there is material hanging on the side wall of the ash hopper and the shape of the current material level surface according to the cloud map, and determining the height of the current material level, including: 4-1) If the material level surface morphology cloud map is composed of one area, it is considered that there is no hanging material on the ash hopper side wall, and step 4-2) is executed; if the material level surface morphology cloud map includes multiple independent areas, and the areas of the multiple areas are different in size, it is considered that there is hanging material on the ash hopper side wall corresponding to the small area, and step 4-2) is executed only for the morphology cloud map corresponding to the large area; 4-2) If the brightness scale of the morphology cloud map determines that the material surface is one of the following: conical material surface, uneven material surface, or flat material surface; 4-3) Obtain the current material level, including: For a flat material surface, the material level average of the material level surface morphology cloud map is taken as the current material level height; For uneven material surface, the maximum value of all peak values ​​of the material level surface morphology cloud map is taken as the current material level height; For a conical material surface, the peak value of the material level surface morphology cloud map is taken as the current material level height.

6. The monitoring method according to claim 5, characterized in that: In step 1), the method for determining the measurement error threshold ΔA is as follows: after turning on the multi-point array laser ranging sensor (6) for 2 minutes, start recording ranging data, and measure for 10 seconds under the same working condition, take 100 data values ​​therein to calculate the average value, and the maximum absolute value of the difference between the 100 data values ​​and the average value is the measurement error threshold ΔA.

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