An environmental monitoring system based on lidar

Abstract

The present invention provides an environmental monitoring system based on lidar, including a model construction module that constructs a scene model in proportion according to scene images and trains an environmental standard model with historical data, a data acquisition module that acquires the reflected data of the main lidar with a fixed radio frequency path as the first feedback data, an in-model verification module that substitutes the first feedback data into the environmental standard model to verify whether it is consistent with the environmental standard model, a dynamic positioning module that calls an auxiliary lidar, controls the adjustable radio frequency path of the auxiliary lidar to intersect the fixed radio frequency path, and acquires the feedback data at multiple points as the second feedback data, and regards the second feedback data that does not match the data in the environmental standard model as a suspicious radio frequency path, and a concentration calculation module that determines the pollutant concentration information according to the deposition distance and the first feedback data; the advantage of the present invention is that it can exclude interference factors and accurately monitor the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of lidar applications, and more particularly to an environmental monitoring system based on lidar. Background Art

[0002] Among current environmental monitoring methods, there are methods such as collecting air for pollutant analysis through an analyzer or analyzing through the reflectivity of lidar. Among them, mid-wave infrared lidar technology can achieve accurate monitoring and measurement of atmospheric pollutants and can be widely used in environmental monitoring and environmental protection work. With the continuous improvement of environmental quality monitoring requirements and the exacerbation of environmental pollution problems, the key technologies of mid-wave infrared lidar will play an important role in the field of environmental protection.

[0003] Regarding the existing lidar technology, data is usually collected at fixed detection points, or a wide-area lidar is emitted from top to bottom by an aircraft and then reflected to collect data. Both of the above two methods are easily affected by interference factors. If there is deposition of dust or pollutants, the positioning of the deposition point is poor and accurate monitoring cannot be achieved. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an environmental monitoring system based on lidar, which can exclude interference factors and accurately monitor the environment.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An environmental monitoring system based on lidar, comprising a model construction module, a data collection module, an in-model verification module, a dynamic positioning module, and a concentration calculation module;

[0007] The model construction module constructs a scene model in proportion according to the scene image, and trains the scene model with historical data to obtain an environmental standard model;

[0008] The data collection module obtains the main lidar reflection data of a fixed radio frequency path as the first feedback data;

[0009] The in-model verification module substitutes the first feedback data into the environmental standard model to verify whether the feedback data is consistent when it is consistent with the fixed radio frequency path in the environmental standard model; if not, a positioning instruction is output;

[0010] When the dynamic positioning module obtains the positioning instruction, it calls the auxiliary lidar, controls the adjustable radio frequency path of the auxiliary lidar to intersect with the fixed radio frequency path, and obtains the feedback data collected by the data acquisition module at multiple points on the fixed radio frequency path as the second feedback data. The second feedback data is substituted into the environmental standard model, and the adjustable radio frequency path where the second feedback data does not match the data corresponding to the radio frequency path in the environmental standard model is extracted as the suspicious radio frequency path;

[0011] The concentration calculation module calculates the deposition distance based on the fixed radio frequency path and the suspicious radio frequency path, and then determines the pollutant concentration information based on the deposition distance and the first feedback data.

[0012] Further, the auxiliary lidar includes an aircraft lidar with wide-area illumination and a secondary lidar with adjustable radio frequency angle.

[0013] Further, the dynamic positioning module includes a dynamic positioning sub-module, and the dynamic positioning sub-module includes a selection strategy, and the selection strategy includes a lidar coverage analysis step and a lidar selection step;

[0014] In the lidar coverage analysis step, the ray coordinates corresponding to the fixed radio frequency path of the main lidar in the environmental standard model are mapped to form a coordinate line, and the ray coordinates corresponding to the adjustable radio frequency path of the secondary lidar in the environmental standard model are mapped to form a first radio frequency region;

[0015] In the lidar selection step, it is analyzed whether the coordinate line is completely covered by the first radio frequency region. If so, the secondary lidar is called. If not, the secondary lidar and the aircraft lidar are called respectively.

[0016] Further, the selection strategy further includes a flight area calculation step and a flight range marking step;

[0017] In the flight area calculation step, the part of the radio frequency line not covered by the first radio frequency region is intercepted as the aircraft scanning section, and the obstacles around the aircraft scanning section are marked;

[0018] In the flight range marking step, the area between the aircraft scanning section and the obstacles is marked with a frame line as the flight scanning range.

[0019] Further, the selection strategy further includes a scanning surface superposition step;

[0020] In the scanning surface superposition step, the first radio frequency region and the flight scanning region are spliced to obtain a detection region.

[0021] Further, the selection strategy further includes an obstacle blind area screening step;

[0022] For the obstacle blind area screening step, retrieve the area that the bottom of the scanned obstacle by the secondary lidar is not scanned by the aircraft lidar as the blind area range, substitute the obtained feedback data within the blind area range into the environmental standard model to determine whether they are consistent. If they are consistent, then exclude the blind area range from the first RF area for superposition with the flight scanning area in the scanning plane superposition step.

[0023] Furthermore, it further includes a feedback module. The feedback module substitutes the feedback data within the detection area into the environmental standard model to determine whether they are consistent. If they are not consistent, then mark this area as the deposition area and display the deposition area in the scene model.

[0024] Furthermore, the first RF area is all the spatial ranges scanned by the lidar in the scene model when the secondary lidar rotates 360°.

[0025] Furthermore, it further includes a signal interaction module. When it is necessary to call the aircraft lidar, the signal interaction module controls the main lidar to send a call instruction to the aircraft lidar, and then the aircraft lidar transfers the call instruction to the secondary lidar.

[0026] Furthermore, the historical data includes expert experience and historical data sets. The expert experience and historical data sets are mixed in a fixed ratio and divided into a training set and a validation set. The scene model is trained by the training set to obtain a preliminary model, and then the preliminary model is verified by the validation set to obtain the environmental standard model.

[0027] Advantages of the present invention: By performing three-dimensional scene modeling on the area to be monitored, and then using a large amount of past data for training and verification as a reference environmental standard model, and comprehensively detecting with a main lidar with a fixed RF path as the priority, a secondary lidar with an adjustable RF angle, and an aircraft lidar with wide-area illumination. When auxiliary radar is needed for positioning on the fixed RF path of the main lidar, it is necessary to determine the selection of the auxiliary lidar according to the three-dimensional scene model. For example, when there are obstacles on the fixed RF path that block the RF line of the secondary lidar, it is necessary to call the aircraft lidar at the same time to ensure the accuracy of monitoring. When the RF range of the secondary lidar can completely cover the fixed RF path, it means that there are no obstacles blocking, so the waste caused by the activation of the aircraft lidar can be avoided. Compared with the existing detection methods, the multi-lidar cooperation monitoring of the present invention can ensure the accuracy of environmental monitoring and can perform real-time dynamic monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the system control diagram of the present invention;

[0029] Figure 2This is the overall structure diagram of the present invention.

[0030] Reference numerals: 101, model construction module; 102, data acquisition module; 103, in-model verification module; 104, dynamic positioning module; 105, concentration calculation module; 106, dynamic positioning sub-module; 107, feedback module; 108, signal interaction module. Detailed implementation manners

[0031] The present invention will be further described in detail below with reference to the drawings and embodiments. The same components are denoted by the same reference numerals. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "bottom surface" and "top surface", "inner" and "outer" refer to the directions towards or away from the geometric center of a specific component, respectively.

[0032] In the existing environmental monitoring using lidar technology, data is usually collected at fixed detection points, or wide-area lidar is emitted from top to bottom by an aircraft and then reflected to collect data. Both of the above two methods are easily affected by interference factors. If dust or pollutants are deposited, the positioning of the deposition points is poor and accurate monitoring cannot be achieved. Therefore, the present invention designs an environmental monitoring system based on lidar, as Figure 1 shown, which includes a model construction module 101, a data acquisition module 102, an in-model verification module 103, a dynamic positioning module 104, and a concentration calculation module 105;

[0033] The model construction module 101 usually divides the area to be monitored into regions at present. For example, for the ecological area in the city, the previous method was to perform detection by manual sampling or fixed-point sampling. However, this method cannot judge the overall environment. The sampling point is a single point and cannot judge a certain space. Therefore, through intelligent monitoring, a scene model is constructed in proportion to the physical image of the scene. The model includes objects such as houses, trees, and the ground. The construction method is that the aircraft scans and models from bottom to top, then makes one-to-one corrections according to the actual situation, and then trains the scene model with historical data to obtain an environmental standard model. The environmental standard model is a comprehensive model, that is, it includes the positions and sizes of various physical objects and also includes various data. For example, when the air quality is excellent or medium or low, the air data of n points in the space is obtained as historical data to train the scene model, and a model that can display both three-dimensional space images and various data values is obtained.

[0034] Such as Figure 2As shown, the main lidar is a fixed emission source, and the radio frequency line it emits has a fixed radio frequency path. Assuming it is inclined upward, a reflector cooperating with the main lidar is correspondingly set. After the reflector reflects the radio frequency signal of the main lidar, it is received by the receiver, that is, the data acquisition module 102, and the reflected data of the main lidar with a fixed radio frequency path is obtained as the first feedback data, and the first feedback data is a numerical value.

[0035] The in-model verification module 103 substitutes the first feedback data into the environmental standard model to verify whether the feedback data is consistent when it is consistent with the fixed radio frequency path in the environmental standard model; if not, a positioning instruction is output. That is, assuming the output value of the main lidar is A and the reflected value is B, substituting the output value A into the environmental standard model can obtain that when the air quality is excellent under this fixed radio frequency path, the reflected value should be B1. Comparing B1 with B, if B1 is less than B, it means that under the actual fixed radio frequency path, the concentration of particulate matter and dust in the air is relatively large, affecting the penetration of the lidar. However, since the fixed radio frequency path is a line, it is also necessary to locate which part of the space on the fixed radio frequency path has particulate matter or dust deposition.

[0036] To solve the positioning of the deposition, when the dynamic positioning module 104 obtains the positioning instruction, it calls the auxiliary lidar and controls the adjustable radio frequency path of the auxiliary lidar to intersect with the fixed radio frequency path, and obtains the feedback data collected by the data acquisition module 102 at multiple points on the fixed radio frequency path as the second feedback data (the second feedback data is a numerical value). Substitute the second feedback data into the environmental standard model, and extract the adjustable radio frequency path where the second feedback data does not match the data corresponding to the radio frequency path in the environmental standard model as the suspicious radio frequency path. Assume there is only one main lidar T, and the fixed radio frequency path of the main lidar is X1, that is, the positioning method is that the adjustable radio frequency path emitted by the auxiliary lidar Y is X2. Since the dust or particulate matter deposition is a range, the adjustable radio frequency path X2 is also a range, which is centered on the fixed radio frequency path X1 and must cover the fixed radio frequency path X1. The reflected values C1 - Cn at multiple points on the fixed radio frequency path X1 are obtained through the auxiliary lidar Y, and the output value of the auxiliary lidar Y is always A. Then, similarly, substituting A into the environmental standard model to obtain D1 - Dn, and comparing D1 - Dn with C1 - Cn in turn. If the actual reflected value is less than the feedback value of the model, it is considered suspicious, and according to the distribution of the suspicious points, the suspicious points will be identified as deposition points.

[0037] The concentration calculation module 105 calculates the deposition distance based on the fixed RF path and the suspicious RF path. Since the fixed RF path X1 is known and it is known which part of the fixed RF path X1 is the deposition section (deposition distance) through positioning, the pollutant concentration information is then obtained by judging according to the deposition distance and the first feedback data through the existing method of measuring concentration by laser. The above method can only measure the deposition range in one dimension. If multiple dimensions need to be measured, the adjustable RF path X2 of the auxiliary lidar Y is positioned and verified by setting another auxiliary lidar, so that the three-dimensional range of deposition can be accurately displayed in the environmental standard model to help the monitoring personnel monitor intuitively and dynamically.

[0038] Among them, the auxiliary lidar Y includes an aircraft lidar Y1 with wide-area irradiation and a secondary lidar Y2 with adjustable RF angle. The secondary lidar with adjustable RF angle is fixed at a certain position and can rotate 360°. In terms of priority, the priority of the secondary lidar is higher than that of the aircraft lidar. The aircraft lidar is a lidar mounted on an aircraft such as a drone for wide-area irradiation from top to bottom.

[0039] As Figure 1 and Figure 2 shown, the dynamic positioning module 104 includes a dynamic positioning sub-module 106, and the dynamic positioning sub-module 106 includes a selection strategy. The selection strategy includes a lidar coverage analysis step and a lidar selection step;

[0040] The lidar coverage analysis step: construct a three-dimensional coordinate system in the environmental standard model. Map the fixed RF path of the main lidar to the corresponding ray coordinates in the environmental standard model to form a coordinate line X1. Map the adjustable RF path of the secondary lidar to the corresponding ray coordinates in the environmental standard model to form a first RF region. The first RF region is all the spatial ranges scanned by the lidar in the scene model when the secondary lidar rotates 360°. The first RF region includes the adjustable RF paths X2 - Xn;

[0041] Lidar selection steps. Analyze whether the coordinate line is completely covered by the first RF area. If so, call the secondary lidar. If not, call the secondary lidar and the aircraft lidar respectively. Since the fixed RF path X1 is fixed in advance, in this ecological monitoring area, the main lidar T is preset. No matter how trees are planted in the subsequent ecological areas, the fixed RF path X1 of the main lidar T cannot be blocked. However, the secondary lidar Y2 with adjustable RF angle may be blocked by obstacles. Therefore, it is necessary to first determine whether the first RF area of the secondary lidar Y2 can completely cover the fixed RF path X1 of the main lidar T. If it is not completely covered, it means that the secondary lidar Y2 is not sufficient for complete monitoring, and it is necessary to enable the aircraft lidar Y1 to irradiate from above to make up for the monitoring of this blind area.

[0042] Since when the wide-area irradiation of the aircraft lidar is enabled, it is necessary to improve the monitoring efficiency and save flight time, the selection strategy also includes a flight area calculation step and a flight range marking step;

[0043] Flight area calculation step. Intercept the part of the RF line not covered by the first RF area as the aircraft scanning segment, and mark the obstacles around the aircraft scanning segment, such as Figure 2 As shown, the first RF area can completely cover the M1 segment in the RF line (fixed RF path X1), and the M2 segment in X1 not covered by the first RF area needs to be intercepted as the aircraft scanning segment;

[0044] Flight range marking step. Frame and mark the area between the aircraft scanning segment and the obstacles as the flight scanning range, that is, with the M2 segment as the center, scan the area between the surrounding obstacles of the M2 segment. Assuming that the tree blocks the secondary lidar Y2, when the aircraft lidar Y1 irradiates from above, draw a frame line around the M2 segment and part of the tree as the scanning range to provide targeted monitoring for the aircraft lidar Y1.

[0045] Since when the first RF area does not completely cover the fixed RF path X1 of the main lidar T, it is necessary to combine the aircraft lidar Y1 for scanning, the selection strategy also includes a scanning plane superposition step;

[0046] Specifically, in the scanning plane superposition step, splice the first RF area and the flight scanning area to obtain a detection area. The detection area covers the fixed RF path X1 and also detects the surrounding area of X1 by spreading outward, for the purpose of comprehensive inspection.

[0047] The selection strategy also includes an obstacle blind area screening step;

[0048] In the obstacle blind spot screening step, the area not scanned by the aircraft laser radar Y1 at the bottom of the obstacle scanned by the secondary laser radar Y2 is taken as the blind spot range, and the feedback data obtained within the blind spot range is substituted into the environmental standard model to determine whether they are consistent. If they are consistent, the blind spot range is eliminated in the first radio frequency area and used for superimposition with the flight scanning area in the scanning surface superposition step. Assuming that the obstacle is a tree, the normal dust deposition above the tree will be blocked by the branches and leaves, while the secondary laser radar Y2 can detect the bottom of the branches and leaves. Therefore, the area below the branches and leaves is taken as the blind spot range of the aircraft laser radar Y1, and the blind spot range detection The measured data values ​​can also be substituted into the environmental standard model for verification. If the verification is consistent, it means that the blind area range is normal and the blind area range can be excluded. Only other superimposed areas are analyzed. It also includes a feedback module 107. The feedback module 107 substitutes the feedback data in the detection area into the environmental standard model to determine whether it is consistent. If not, the area is marked as a deposition area, and the deposition area is displayed in the scene model. The monitoring personnel can then intuitively observe the location of dust deposition in the ecological area, the range of deposition, etc. in the model, which is helpful for subsequent processing and dynamic monitoring.

[0049] Since the secondary laser radar Y2 is located between various obstacles, if the emission angle of the secondary laser radar Y2 needs to be adjusted, if the adjustment signal is directly sent from the main laser radar to the secondary laser radar, the requirements for the interactive signal are relatively high. Therefore, a signal interaction module 108 is also included. When the aircraft laser radar needs to be called, the signal interaction module 108 controls the main laser radar to send a call instruction to the aircraft laser radar, and the aircraft laser radar then transfers the call instruction to the secondary laser radar. The instructions are transmitted from bottom to top, and then transferred from top to bottom. The speed is relatively faster and the instruction transmission intensity is higher.

[0050] Historical data includes expert experience and historical data sets. The expert experience and historical data sets are mixed in a fixed ratio and divided into training sets and validation sets. Expert experience is generally an estimate, which is obtained by collecting data from collection points and then evaluating it. The historical data set is a data set from previous lidar tests. Assuming the mixing ratio of the two is 3:7, among the 1000 data sets, there are 300 expert experience data sets and 700 historical data sets. Among the 1000 data sets, the ratio of training sets to validation sets is 7:3. The scene model is trained with the training set to obtain a preliminary model, and then the preliminary model is verified with the validation set to obtain the environmental standard model.

[0051] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A laser radar-based environmental monitoring system, comprising a model building module, a data acquisition module, a model entry verification module, a dynamic positioning module and a concentration calculation module; The model building module builds a scene model in proportion to the scene image, and trains the scene model with historical data to obtain an environmental standard model; The data acquisition module acquires the reflection data of the main laser radar with a fixed radio frequency path as the first feedback data; The input model verification module substitutes the first feedback data into the environmental standard model to verify whether the feedback data is consistent with the fixed radio frequency behavior in the environmental standard model; if not, outputs a positioning instruction; The dynamic positioning module, when acquiring the positioning instruction, calls the auxiliary laser radar, controls the adjustable radio frequency behavior of the auxiliary laser radar to intersect with the fixed radio frequency behavior, and acquires the feedback data collected by the data acquisition module at multiple points of the fixed radio frequency behavior as the second feedback data, substitutes the second feedback data into the environmental standard model, and extracts the adjustable radio frequency behavior whose data does not match the corresponding radio frequency behavior in the environmental standard model as the suspicious radio frequency behavior; the auxiliary laser radar includes an aircraft laser radar with wide-area illumination and a secondary laser radar with an adjustable radio frequency angle; The concentration calculation module obtains the deposition distance by calculation according to the fixed radio frequency behavior and the suspicious radio frequency behavior, and then obtains the pollutant concentration information according to the deposition distance and the first feedback data.

2. The laser radar-based environmental monitoring system according to claim 1, characterized in that: The dynamic positioning module includes a dynamic positioning submodule, and the dynamic positioning submodule includes a selection strategy, and the selection strategy includes a laser radar coverage analysis step and a laser radar selection step; The laser radar coverage analysis step maps the fixed radio frequency behavior of the primary laser radar to the corresponding ray coordinates in the environmental standard model to form a coordinate line, and maps the adjustable radio frequency behavior of the secondary laser radar to the corresponding ray coordinates in the environmental standard model to form a first radio frequency area; The laser radar selection step analyzes whether the coordinate line is completely covered by the first radio frequency area. If so, the secondary laser radar is called. If not, the secondary laser radar and the aircraft laser radar are called respectively.

3. The laser radar-based environmental monitoring system according to claim 2, characterized in that: The selection strategy also includes a flight area calculation step and a flight range marking step; The flight area calculation step includes intercepting the portion of the coordinate line not covered by the first radio frequency area as an aircraft scanning segment, and marking obstacles around the aircraft scanning segment; The flight range marking step is to mark the area between the aircraft scanning segment and the obstacle with a frame line as the flight scanning range.

4. The laser radar-based environmental monitoring system according to claim 3, characterized in that: The selection strategy also includes a scanning surface superposition step; The scanning surface superposition step is to splice the first radio frequency area and the flight scanning area to obtain a detection area.

5. The laser radar-based environmental monitoring system according to claim 4, characterized in that: The selection strategy also includes an obstacle blind spot screening step; The obstacle blind spot screening step retrieves the area not scanned by the aircraft laser radar at the bottom of the secondary laser radar that scans obstacles as the blind spot range, substitutes the feedback data obtained within the blind spot range into the environmental standard model to determine whether they are consistent; if they are consistent, the blind spot range is eliminated in the first radio frequency area and used for superimposition with the flight scanning area in the scanning surface superposition step.

6. The laser radar-based environmental monitoring system according to claim 5, characterized in that: It also includes a feedback module, which substitutes the feedback data in the detection area into the environmental standard model to determine whether it is consistent. If it is not consistent, the area is marked as a deposition area, and the deposition area is displayed in the scene model.

7. The laser radar-based environmental monitoring system according to claim 2, characterized in that: The first radio frequency area is the entire spatial range scanned by the laser radar in the scene model when the secondary laser radar rotates 360°.

8. The laser radar-based environment monitoring system according to claim 6, characterized in that: It also includes a signal interaction module, which controls the main laser radar to send a call instruction to the aircraft laser radar when the aircraft laser radar needs to be called, and the aircraft laser radar then transfers the call instruction to the secondary laser radar.

9. The laser radar-based environment monitoring system according to claim 1 or 7, characterized in that: The historical data includes expert experience and historical data sets. The expert experience and the historical data sets are mixed in a fixed ratio and divided into a training set and a verification set. The scene model is trained with the training set to obtain a preliminary model, and then the preliminary model is verified with the verification set to obtain an environmental standard model.

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