Coal pile profile data acquisition method

Abstract

The application relates to the technical field of coal pile management, in particular to a coal pile contour data acquisition method. The method comprises the following steps: generating a coal pile contour acquisition time axis, and generating a surveying and mapping instruction according to a preset time node; a surveying and mapping system acquires the coal pile surveying and mapping instruction, acquires coal pile warehouse in-out data between a current time node and a previous time node and coal pile contour data of the previous time node, and generates a predicted coal pile quality; working parameters of the surveying and mapping system are set, and coal pile contour data is generated according to collected data of the surveying and mapping system; the coal pile contour data is judged according to the predicted coal pile quality, and whether secondary surveying and mapping is performed is judged according to a judgment result. According to the coal pile warehouse management requirement, a preset time axis is generated, and different surveying and mapping instructions are generated according to different requirements, so that the measurement efficiency is improved while the measurement precision is ensured. Meanwhile, time nodes and surveying and mapping instructions are set according to operation time of coal yard stacking, taking, rolling and dumping, the coal pile contour data is updated in a timely manner, and timeliness is ensured.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of coal pile management, in particular to a coal pile contour data acquisition method. BACKGROUND

[0002] In a thermal power plant and a steel plant, coal storage management is an important link in production and operation, and the quality of the coal storage management directly affects the normal operation of the plant. Therefore, the enterprise must comprehensively measure the coal storage at the end of each month, and fuel management of the enterprise has become an important work of production and operation and management, which has attracted high attention of each power plant.

[0003] Because the coal pile is large in volume and irregular in shape, a manual coal counting method has been used for a long time. The manual coal counting method is to measure the volume of the coal pile and then calculate the coal storage quantity. To measure the volume of the coal pile, coal pile contour data needs to be collected, but the current coal pile contour data collection method is low in efficiency, and the coal pile contour data cannot be automatically updated in time according to the change of the coal yard, and the measurement accuracy, speed, reliability and real-time performance cannot meet the current needs. SUMMARY

[0004] The application aims to solve the above technical problems, and provides a coal pile contour data acquisition method to improve the measurement accuracy, speed and timeliness of the coal pile contour data.

[0005] In some embodiments of the application, according to the coal pile inventory requirement, a time axis is preset, and different surveying and mapping instructions are generated according to different requirements of daily inventory, monthly inventory, quarterly inventory and annual inventory, so as to improve the measurement efficiency while ensuring the measurement accuracy. Meanwhile, according to the time of the coal yard stacking, taking, rolling and dumping operations, a time node and a surveying and mapping instruction are set to update the coal pile contour data in time and ensure the timeliness.

[0006] In some embodiments of the application, different levels of working modes are set to meet various requirements of coal pile monitoring, improve the measurement efficiency, and verify the initially collected coal pile contour data according to the predicted coal pile quality, so as to ensure the accuracy of the coal pile contour data through multiple collection modes. The allowable error range is set according to the preset coal pile quality matrix and the difference matrix to ensure the accuracy of the judgment result.

[0007] In some embodiments of the application, a coal pile contour data acquisition method is provided, which comprises:

[0008] Step 1: Generate a coal pile contour acquisition time axis, and generate a surveying and mapping instruction according to a preset time node;

[0009] Step two: the mapping system obtains the coal pile mapping instruction, obtains the coal pile in-out data between the current time node and the last time node and the coal pile contour data of the last time node, and generates the predicted coal pile quality;

[0010] Step three: set the working parameters of the mapping system, and generate the coal pile contour data according to the collection data of the mapping system;

[0011] Step four: judging the coal pile contour data according to the predicted coal pile quality, and judging whether to perform secondary mapping according to the judgment result.

[0012] In some embodiments of the present application, when the mapping system generates the coal pile contour data according to the collection data, it includes:

[0013] The mapping system obtains scanning area data, and divides a plurality of scanning sub-regions and sets a plurality of mapping subsystems according to the scanning area data;

[0014] The mapping subsystem collects point cloud data in the scanning sub-region;

[0015] The time monitoring unit generates a time tag;

[0016] According to the time tag, all the point cloud data collected by the mapping subsystem is obtained, and the point cloud data is filtered and denoised;

[0017] Obtain the scanner position data, fuse the point cloud data according to the scanner position data, and generate the coal pile contour data.

[0018] In some embodiments of the present application, the step one includes:

[0019] Obtain the preset time node data, and generate the mapping instruction according to the time node data, the mapping instruction including a first-level mapping instruction, a second-level mapping instruction and a third-level mapping instruction;

[0020] According to the mapping instruction, set the scanning mode of the mapping system;

[0021] The scanning mode includes a first-level working mode, a second-level working mode and a third-level working mode;

[0022] When the mapping instruction is a first-level mapping instruction, set the mapping system to a first-level working mode;

[0023] When the mapping instruction is a second-level mapping instruction, set the mapping system to a second-level working mode;

[0024] When the mapping instruction is a third-level mapping instruction, set the mapping system to a third-level working mode.

[0025] In some embodiments of the present application, the fourth step comprises:

[0026] Obtaining the coal pile profile data, and generating a coal pile mass according to the coal pile profile data;

[0027] Generating a first difference value according to the coal pile mass and the predicted coal pile mass;

[0028] Determining whether to perform a second surveying according to the first difference value.

[0029] In some embodiments of the present application, when determining whether to perform a second surveying according to the first difference value, the method comprises:

[0030] A preset coal pile mass matrix A is set, and A (A1, A2, A3, A4) is set, wherein A1 is a first preset coal pile mass, A2 is a second preset coal pile mass, A3 is a third preset coal pile mass, and A4 is a fourth preset coal pile mass, and A1

[0031] A preset difference value matrix B is set, and B (B1, B2, B3, B4) is set, wherein B1 is a first preset difference value, B2 is a second preset difference value, B3 is a third preset difference value, and B4 is a fourth preset difference value, and B1

[0032] Obtaining a coal pile mass a, and setting an allowable difference value b according to the relationship between the preset coal pile mass matrix A and the preset difference value matrix B, which is specifically:

[0033] When a

[0034] When A1

[0035] When A2

[0036] When A3

[0037] When the first difference value is greater than the allowable difference value b, a second surveying instruction is generated, and the surveying system performs a second surveying.

[0038] In some embodiments of the present application, when performing a second surveying, the method comprises:

[0039] Setting a working mode during a second surveying according to the working mode during a first surveying;

[0040] Obtaining coal pile profile data generated by the second surveying;

[0041] The first mapping generated coal pile contour data and the second mapping generated coal pile contour data are judged, and the coal pile contour data is generated according to the judgment result.

[0042] In some embodiments of the present application, when the working mode during the second mapping is set, it includes:

[0043] When the working mode during the first mapping is the first level working mode or the second level working mode, the working mode during the second mapping is set to the second level working mode.

[0044] When the working mode during the first mapping is the third level working mode, the working mode during the second mapping is set to the third level working mode.

[0045] In some embodiments of the present application, when the coal pile contour data is generated according to the judgment result, it includes:

[0046] When the working mode during the first mapping is different from the working mode during the second mapping, the coal pile contour data is generated according to the second mapping generated coal pile contour data.

[0047] In some embodiments of the present application, when the coal pile contour data is generated according to the judgment result, it further includes:

[0048] When the working mode during the first mapping is the same as the working mode during the second mapping,

[0049] If the difference between the first mapping generated coal pile contour data and the second mapping generated coal pile contour data is less than the preset difference threshold, the coal pile contour data is generated according to the second mapping generated coal pile contour data.

[0050] If the difference between the first mapping generated coal pile contour data and the second mapping generated coal pile contour data is greater than the preset difference threshold, the mapping is performed again, and the coal pile contour data is generated according to the third mapping generated coal pile contour data.

[0051] In some embodiments of the present application, it further includes:

[0052] The working mode during the third mapping is set to the third level working mode.

[0053] Compared with the prior art, the coal pile contour data acquisition method of the embodiments of the present application has the beneficial effects that:

[0054] According to the coal pile storage requirements, a preset time axis is set, and different mapping instructions are generated according to different requirements of daily inspection, monthly inspection, quarterly inspection and annual inspection, so as to ensure the measurement accuracy and improve the measurement efficiency. Meanwhile, according to the time of coal yard stacking, taking, rolling and dumping, time nodes and mapping instructions are set, and the coal pile contour data is updated in time to ensure the timeliness.

[0055] By setting different levels of working modes, various requirements of coal pile monitoring are met, the measurement efficiency is improved, and the initial collected coal pile contour data is verified according to the generated predicted coal pile quality, the accuracy of the coal pile contour data is ensured through multiple collection modes. And by presetting the allowable error range according to the preset coal pile quality matrix and difference matrix, the accuracy of the judgment result is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 is a flowchart of a coal pile contour acquisition method in a preferred embodiment of the present application;

[0057] Figure 2 is a data processing flowchart in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0058] The specific embodiments of the present application will be further described in detail below in combination with the drawings and embodiments. The following embodiments are used to illustrate the present application, but not to limit the scope of the present application.

[0059] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0060] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0061] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0062] As shown in Figure 1 and Figure 2 The coal pile profile data acquisition method of the preferred embodiment of the present application comprises:

[0063] Step one: generate a coal pile profile acquisition time axis, and generate a surveying and mapping instruction according to a preset time node;

[0064] Step two: the surveying and mapping system acquires the coal pile surveying and mapping instruction, and acquires the coal pile in-out data between the current time node and the previous time node and the coal pile profile data of the previous time node, and generates a predicted coal pile quality;

[0065] Step three: set the working parameters of the surveying and mapping system, and generate the coal pile profile data according to the acquisition data of the surveying and mapping system;

[0066] Step four: judge the coal pile profile data according to the predicted coal pile quality, and judge whether to perform secondary surveying and mapping according to the judgment result.

[0067] Specifically,

[0068] Specifically, the surveying and mapping system uses long-focus laser scanning equipment distributed around the coal yard to realize bird's-eye view real-time dynamic three-dimensional scanning measurement of the entire coal yard without dead angle blind area. The dynamic measurement subsystem can automatically and dynamically acquire the three-dimensional coordinates of the coal yard surface, and can complete the scanning data acquisition of the scanning units distributed in the coal yard range within 10 minutes, and can perform calculation and fusion to generate a unified three-dimensional model of the entire circular coal yard. The data fusion requires a unified coordinate system and a unified space-time, and the three-dimensional model is realistic. The system is fixedly installed in the coal yard and can perform all-weather and dynamic three-dimensional data acquisition: the system uses a fine network construction algorithm to reconstruct a triangular network with all three-dimensional point data on the section. When the scanning unit enters the next scanning period, it can automatically update the changed part of the coal yard data, and the updated data needs to change the time label of the three-dimensional model. The three-dimensional graphics can support rotation, scaling, translation and other operations.

[0069] Specifically, when generating the coal pile profile data according to the acquisition data of the surveying and mapping system, it comprises:

[0070] The surveying system obtains scanning area data, and divides a plurality of scanning sub-areas and sets a plurality of surveying subsystems according to the scanning area data;

[0071] The surveying subsystem collects point cloud data in the scanning sub-area;

[0072] The time monitoring unit generates a time tag;

[0073] According to the time tag, point cloud data collected by all surveying subsystems is obtained, and the point cloud data is filtered and denoised;

[0074] Obtain scanner position data, fuse the point cloud data according to the scanner position data, and generate coal pile contour data.

[0075] Specifically, the point cloud data and the position data are subjected to coordinate transformation, the system eliminates errors, and the coal pile contour data is generated after grid processing.

[0076] Specifically, the surveying subsystem is preferably a laser scanner, and the laser scanner should be configured with a fully enclosed transparent protective cover. The protective cover is surrounded by a low reflectivity self-cleaning glass, which can ensure that the laser can pass smoothly without affecting the measurement accuracy. At the same time, the protective cover should be equipped with a corresponding air conditioning device, which should be able to work reliably in a high-vibration, high-dust, high-humidity, and smog environment. The air conditioning device should be able to effectively control the working environment temperature of the laser scanner within the most suitable range, effectively protect the laser scanner, and prevent the greenhouse temperature inside the cover from being too high due to sunlight exposure, or the laser scanner from not being able to operate normally or shortening the service life of the laser scanner due to the surrounding environment temperature being too low.

[0077] Specifically, the data control part collects the point distance from the surface feature points of the coal pile scanned by each scanner to the scanning center of each scanner. This data also includes the time tag of the start of scanning and the scanning range of each scanner, which is used to match the time and spatial position of the coal yard stacking, taking, rolling, and dumping operations. It is used to update the three-dimensional graphic data in real time, improve the data processing efficiency, and realize the three-dimensional dynamic display of the coal yard.

[0078] In the preferred embodiment of the present application, step one includes:

[0079] Obtain preset time node data, and generate surveying instructions according to the time node data, the surveying instructions including first-level surveying instructions, second-level surveying instructions, and third-level surveying instructions;

[0080] Specifically, when the demand is daily inventory demand, temporary inventory demand, or data update demand after entering or leaving the warehouse, the first-level surveying instructions are generated after the coal yard stacking, taking, rolling, and dumping operations;

[0081] The second-level surveying instructions are generated for the inventory demand at the end of the month and the inventory demand at the end of the quarter.

[0082] The three-level mapping instructions are generated according to the annual inventory demand.

[0083] The scanning mode of the mapping system is set according to the mapping instructions;

[0084] The scanning mode includes a first-level working mode, a second-level working mode and a third-level working mode;

[0085] Specifically, the first-level scanning mode is 2-minute rough scanning, the second-level working mode is 3-minute general scanning, and the third-level working mode is 5-minute accurate scanning, and the accuracy of the third-level working mode is better than that of the second-level working mode, and the accuracy of the second-level working mode is better than that of the first-level working mode.

[0086] Specifically:

[0087] When the mapping instruction is a first-level mapping instruction, the mapping system is set to the first-level working mode;

[0088] When the mapping instruction is a second-level mapping instruction, the mapping system is set to the second-level working mode;

[0089] When the mapping instruction is a third-level mapping instruction, the mapping system is set to the third-level working mode.

[0090] It can be understood that in the above embodiment, the time axis is preset according to the coal pile inventory demand, and different mapping instructions are generated according to the different requirements of daily inventory, monthly inventory, quarterly inventory and annual inventory, which ensures the measurement accuracy while improving the measurement efficiency. At the same time, according to the time of coal yard stacking, taking, rolling and dumping, time nodes and mapping instructions are set, and coal pile contour data is updated in time to ensure timeliness. By setting different levels of working mode, the measurement efficiency is improved to meet the various requirements of coal pile monitoring.

[0091] In some embodiments of the application, step four includes:

[0092] Obtaining coal pile contour data and generating coal pile quality according to the coal pile contour data;

[0093] Generating a first difference according to the coal pile quality and the predicted coal pile quality;

[0094] According to the first difference, it is judged whether to perform secondary mapping.

[0095] Specifically, when judging whether to perform secondary mapping according to the first difference, it includes:

[0096] A coal pile quality matrix A is preset, and A (A1, A2, A3, A4) is set, wherein A1 is a first preset coal pile quality, A2 is a second preset coal pile quality, A3 is a third preset coal pile quality, A4 is a fourth preset coal pile quality, and A1

[0097] a preset difference value matrix B is set, and B (B1, B2, B3, B4) is set, wherein B1 is a first preset difference value, B2 is a second preset difference value, B3 is a third preset difference value, and B4 is a fourth preset difference value, and B1

[0098] The quality of the coal pile a is obtained, and a permissible difference value b is set according to the relationship between the preset coal pile quality matrix A and the preset difference value matrix B, and specifically:

[0099] When a

[0100] When A1

[0101] When A2

[0102] When A3

[0103] When the first difference value is greater than the permissible difference value b, a secondary mapping instruction is generated, and the mapping system performs secondary mapping.

[0104] It can be understood that in the above embodiments, the permissible error range is set according to the preset coal pile quality matrix and the difference value matrix, which ensures the accuracy of the judgment result.

[0105] In some embodiments of the present application, the secondary mapping includes:

[0106] The working mode during the second mapping is set according to the working mode during the first mapping;

[0107] Obtain the coal pile contour data generated by the second mapping;

[0108] The coal pile contour data generated by the first mapping and the coal pile contour data generated by the second mapping are judged, and the coal pile contour data is generated according to the judgment result.

[0109] Specifically, when setting the working mode during the second mapping, it includes:

[0110] When the working mode during the first mapping is a first level working mode or a second level working mode, the working mode during the second mapping is set to a second level working mode;

[0111] When the working mode during the first mapping is a third level working mode, the working mode during the second mapping is set to a third level working mode.

[0112] Specifically, when generating the coal pile contour data according to the judgment result, it includes:

[0113] When the working mode at the first mapping is different from the working mode at the second mapping, the selected coal pile contour data is generated according to the coal pile contour data generated by the second mapping.

[0114] Specifically, when the coal pile contour data is generated according to the judgment result, it further includes:

[0115] When the working mode at the first mapping is the same as the working mode at the second mapping,

[0116] If the difference between the coal pile contour data generated by the first mapping and the coal pile contour data generated by the second mapping is less than the preset difference threshold, the coal pile contour data is generated according to the coal pile contour data generated by the second mapping;

[0117] If the difference between the coal pile contour data generated by the first mapping and the coal pile contour data generated by the second mapping is greater than the preset difference threshold, mapping is performed again, and the coal pile contour data is generated according to the coal pile contour data generated by the third mapping.

[0118] Specifically, the working mode at the third mapping is set to a three-level working mode.

[0119] It can be understood that in the above embodiment, the initially collected coal pile contour data is verified according to the generated predicted coal pile quality, and the accuracy of the coal pile contour data is ensured through multiple collection methods.

[0120] According to the first concept of the present application, different mapping instructions are generated according to the different requirements of daily inventory, monthly inventory, quarterly inventory and annual inventory according to the preset time axis, which improves the measurement efficiency while ensuring the measurement accuracy. At the same time, according to the operation time of coal yard stacking, taking, rolling and dumping, time nodes and mapping instructions are set to update the coal pile contour data in time and ensure the timeliness.

[0121] According to the second concept of the present application, different levels of working modes are set to meet various requirements of coal pile monitoring, improve measurement efficiency, and verify the initially collected coal pile contour data according to the generated predicted coal pile quality. Through multiple collection methods, the accuracy of the coal pile contour data is ensured. And by presetting the preset coal pile quality matrix and the difference matrix, the allowable error range is set to ensure the accuracy of the judgment result.

[0122] The above is only a preferred embodiment of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, several improvements and replacements can be made without departing from the technical principles of the present application, and these improvements and replacements should be considered as the protection scope of the present application.

Claims

1. A method for acquiring coal pile outline data, characterized in that, Including: Step 1: Generate a time axis for obtaining the coal pile contour, and generate a surveying and mapping instruction according to a preset time node; Step 2: The surveying and mapping system obtains the coal pile surveying and mapping instruction, and obtains the coal pile inbound and outbound data between the current time node and the previous time node and the coal pile contour data of the previous time node, and generates a predicted coal pile quality; Step 3: Set the working parameters of the surveying and mapping system, and generate coal pile contour data according to the collected data of the surveying and mapping system; Step 4: Judge the coal pile contour data according to the predicted coal pile quality, and judge whether to perform secondary surveying and mapping according to the judgment result; The said Step 1 includes: Obtain preset time node data, and generate a surveying and mapping instruction according to the time node data, and the surveying and mapping instruction includes a first-level surveying and mapping instruction, a second-level surveying and mapping instruction and a third-level surveying and mapping instruction; Set the scanning mode of the surveying and mapping system according to the surveying and mapping instruction; The scanning mode includes a first-level working mode, a second-level working mode and a third-level working mode; When the surveying and mapping instruction is a first-level surveying and mapping instruction, set the surveying and mapping system to the first-level working mode; When the surveying and mapping instruction is a second-level surveying and mapping instruction, set the surveying and mapping system to the second-level working mode; When the surveying and mapping instruction is a third-level surveying and mapping instruction, set the surveying and mapping system to the third-level working mode; The said Step 4 includes: Obtain the coal pile contour data, and generate a coal pile quality according to the coal pile contour data; Generate a first difference according to the coal pile quality and the predicted coal pile quality; Judge whether to perform secondary surveying and mapping according to the first difference; When judging whether to perform secondary surveying and mapping according to the first difference, it includes: Preset a coal pile quality matrix A, set A(A1, A2, A3, A4), where A1 is the first preset coal pile quality, A2 is the second preset coal pile quality, A3 is the third preset coal pile quality, A4 is the fourth preset coal pile quality, and A1 < A2 < A3 < A4; Preset a difference matrix B, set B(B1, B2, B3, B4), where B1 is the first preset difference, B2 is the second preset difference, B3 is the third preset difference, B4 is the fourth preset difference, and B1 < B2 < B3 < B4; Obtain the coal pile quality a, and set an allowable difference b according to the relationship between the preset coal pile quality matrix A and the preset difference matrix B, and specifically: When a < A1, set the first preset difference B1 as the allowable difference b; When A1 < a < A2, set the second preset difference B2 as the allowable difference b; When A2 < a < A3, set the third preset difference B2 as the allowable difference b; When A3 < a < A4, set the fourth preset difference B4 as the allowable difference b; When the first difference is greater than the allowable difference b, generate a secondary surveying and mapping instruction, and the surveying and mapping system performs secondary surveying and mapping.

2. The method for acquiring coal pile outline data as described in claim 1, characterized in that, When generating the coal pile contour data according to the collected data of the surveying and mapping system, it includes: The surveying and mapping system obtains the scanning area data, and divides a number of scanning sub-areas according to the scanning area data and sets a number of surveying and mapping subsystems; The surveying and mapping subsystem collects the point cloud data in the scanning sub-area; The time monitoring unit generates a time tag; All point cloud data collected by the surveying subsystem are obtained according to the time tag, and the point cloud data is filtered and noise is reduced. Acquire scanner position data, and fuse the point cloud data based on the scanner position data to generate coal pile outline data.

3. The method for acquiring coal pile outline data as described in claim 2, characterized in that, The secondary surveying includes: The working mode for the second survey should be set according to the working mode during the first survey. Obtain the coal pile outline data generated from the second survey; The coal pile outline data generated from the first and second surveys are evaluated, and coal pile outline data is generated based on the evaluation results.

4. The method for acquiring coal pile outline data as described in claim 3, characterized in that, Setting the working mode for the second survey includes: When the working mode during the first survey is either the first-level working mode or the second-level working mode, the working mode during the second survey is set to the second-level working mode. When the working mode during the first survey is the third-level working mode, the working mode during the second survey is set to the third-level working mode.

5. The method for acquiring coal pile outline data as described in claim 4, characterized in that, When generating coal pile outline data based on the judgment result, the following steps are included: If the working mode during the first survey is different from the working mode during the second survey, then coal pile outline data is generated based on the coal pile outline data generated during the second survey.

6. The method for acquiring coal pile outline data as described in claim 5, characterized in that, When generating coal pile outline data based on the judgment result, the method further includes: When the working mode during the first survey is the same as the working mode during the second survey... If the difference between the coal pile outline data generated by the first survey and the coal pile outline data generated by the second survey is less than a preset difference threshold, then coal pile outline data is generated based on the coal pile outline data generated by the second survey. If the difference between the coal pile outline data generated by the first survey and the coal pile outline data generated by the second survey is greater than a preset difference threshold, the survey is performed again, and coal pile outline data is generated based on the coal pile outline data generated by the third survey.

7. The method for acquiring coal pile outline data as described in claim 6, characterized in that, Also includes: The working mode was set to level three during the third survey.

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