Method for determining the condition of a working device in a pipeline

Abstract

The invention relates to a computer-implemented method for determining the state of a working device in a pipeline designed for transporting fluids, comprising the steps of: - Providing initial magnetic field data of a particularly remanent magnetic field of the pipeline, recorded with at least one first magnetic field sensor of the working device, wherein the initial magnetic field data form a first signal profile of the magnetic field measured by the first magnetic field sensor along a section of the pipeline, - Providing second magnetic field data of the magnetic field recorded by at least one second magnetic field sensor of the working device arranged axially offset to the first magnetic field sensor, wherein the second magnetic field data form a second signal waveform of the magnetic field recorded by the second magnetic field sensor, - Matching the first and second magnetic field data to determine a time offset of the signal waveforms, - Determining the speed of the working device from the time difference and the distance between the two magnetic field sensors.

Description

[0001] The invention relates to a computer-implemented method for determining the state of a working device in a pipeline designed for transporting fluids, a data processing device and a computer program for carrying out such a method, a corresponding computer-readable medium, a method for determining the state of a working device moving in a pipeline, and a working device for use in a pipeline designed for transporting fluids.

[0002] During inline inspections of pipelines, it is regularly necessary to determine the general condition of the equipment, particularly its speed and position within the pipeline. For position determination, methods such as using equipment with an odometer, equipment that communicates with a magnetic marker on the outside of the pipeline using electromagnetic waves, and / or equipment with a transmitter unit that communicates with receivers positioned along the pipeline are known. However, both odometers and markers are complex and expensive to use. Furthermore, the use of odometers is undesirable in water-bearing pipelines due to the biofilm present on the pipe walls. In these pipelines, the equipment should ideally be operated without contact with the pipe walls.Furthermore, the use of markers is neither continuously nor economically feasible, for example, in underground sections of the pipeline.

[0003] The present invention is therefore based on the objective of enabling a simple and cost-effective determination of state while at least partially avoiding the disadvantages of the prior art.

[0004] According to the invention, this problem is solved by a computer-implemented method with the features of claim 1, a data processing device according to claim 8, a computer program according to claim 9, a computer-readable medium according to claim 10, a method according to claim 11, and a working device according to claim 19. Further advantageous embodiments of the invention can be found in the respective dependent claims and the following description.

[0005] The computer-implemented method according to the invention for determining the state of a working device in a pipeline designed for transporting fluids comprises the following steps: - Providing first magnetic field data of a particularly remanent magnetic field of the pipeline, recorded with at least one first magnetic field sensor of the working device, wherein the first magnetic field data represent and / or depict a first signal profile of the magnetic field measured by the first magnetic field sensor along a section of the pipeline (18), - Providing second magnetic field data of the magnetic field acquired by at least one second magnetic field sensor of the working device arranged axially offset to the first magnetic field sensor, wherein the second magnetic field data represent and / or depict a second signal waveform of the magnetic field data acquired by the second magnetic field sensor, - Matching the first and second magnetic field data to determine a time offset of the signal waveforms, - Determining the speed of the working device from the time difference and the distance between the two magnetic field sensors.

[0006] The computer-implemented method according to the invention is based on the understanding that the working device in the pipeline, in particular a passively driven inspection pig, with its two magnetic field sensors offset by a distance d in the axial direction, each records a characteristic signal profile of the magnetic field of a section of the pipeline, and that a time offset of these signal profiles can be determined by matching these signal profiles, or the first and second magnetic field data. The velocity is then deduced from the known axial distance between the magnetic field sensors. For a working device located in the pipeline, in particular an inspection pig, the axial direction generally corresponds to the direction of the longitudinal center axis of the pipeline if the inspection device is arranged centrally in the pipeline.During operation, the spacing of the magnetic field sensors of the working device corresponds to a spacing of the magnetic field sensors relative to the longitudinal center axis of the pipeline.

[0007] Matching magnetic field data involves assigning magnetic field data to each other in such a way that identical or sufficiently similar signal components, edges, and extrema are identified and matched to determine the time offset. The temporal positioning or assignment of these waveforms then defines the time interval between identical signal components from the first and second magnetic field sensors, and thus the time offset of the signal waveforms. It is understood that, for defining the time interval, the magnetic field data are recorded over time, and the evaluation is always performed over a specific time period, corresponding to a sufficiently long section of the pipeline traversed by the measuring device.

[0008] In particular, two identical magnetic field sensors are used at a distance from each other in the axial direction, which are also arranged at an identical distance from the pipe wall for the operating situation.

[0009] Particularly for pipelines with a biofilm on the inside of their pipe walls, it is advantageous if the computer-implemented method does not use data from mechanical sensors that contact the pipe wall, and if the corresponding working device does not have a mechanical speed or distance measurement capability. Specifically, the device is odometer-free, or the computer-implemented method is odometer-data-free, so that contact with the wall can be minimized.

[0010] It is understood that the working equipment, when traveling along the pipeline, moves within the pipeline itself, i.e., along a pipeline wall. Specifically, this refers to passively moved working equipment, or data relating to passively moved working equipment and working equipment moved by the medium within the pipeline.

[0011] To improve data analysis, the magnetic field data is frequency-filtered before matching to utilize low-frequency components. Preferably, the upper cutoff for the frequency filtering is 5 Hz; alternatively or additionally, a lower cutoff for the frequency filtering can be 1 Hz. Magnetic field data recorded by magnetic field sensors is particularly meaningful in the range from 1 Hz to 5 Hz. A DTW algorithm is used to match the data and, in particular, to determine the time offset. Such a Dynamic Time Warp algorithm enables the assignment of similar data segments and thus a corresponding mapping of corresponding parts of the signal waveforms. Following this mapping, the time offset between the corresponding parts of the signal waveforms can then be derived.

[0012] It is understood that the matching process is carried out primarily automatically on the data processing device, i.e., a computer. The data processing device has the usual means for this purpose.

[0013] To provide the first magnetic field data, the computer-implemented method according to a further development of the invention combines the magnetic field data from MFL sensors of a first MFL sensor array. This makes the magnetic field data set more informative with regard to characteristic magnetic profiles present in the circumferential direction. The same applies to the provision of the second magnetic field data in the form of combined data from an MFL sensor array with second magnetic field sensors. An improved correlation of the signal profiles can be achieved by means of the signal profiles of the MFL sensors of two axially spaced sensor arrays. Alternatively, the magnetic field data of one sensor array can also be matched with a magnetic field data set that does not originate from a sensor array.Sensor rings have several magnetic field sensors in the circumferential direction in order to detect the inner surface of a pipe wall as completely as possible in the circumferential direction.

[0014] Alternatively or additionally, the magnetic field data are those from highly sensitive magnetic field sensors, which preferably have a sensitivity of < 3 mT and more preferably < 0.2 mT. Accordingly, to provide the first magnetic field data, the magnetic field data of two highly sensitive first magnetic field sensors can be combined, and / or to provide the second magnetic field data, the magnetic field data of at least two highly sensitive second magnetic field sensors can be combined.

[0015] The first and second magnetic field data are, in particular, data of the remanent magnetic field of the pipeline, preferably acquired via at least one highly sensitive second magnetic field sensor. These magnetic field data of the remanent magnetic field in the pipeline are sometimes more informative than those of an MFL sensor if the latter measures a previously applied magnetic field or its leakage flux and thus primarily detects the defect-related anomalies in the pipeline.

[0016] Using a DTW algorithm, the extensive data sets from two magnetic field sensors can be measured over longer distances and matched relatively quickly, allowing the computer-implemented method to be carried out virtually in real time with a corresponding data processing device on a suitable work tool. It is important that the time interval for matching the signal waveforms is selected so that the relevant section of the pipeline is traversed by both sensors at the typical speeds of the work tool within the pipeline. Alternatively, the magnetic field, time, and other data are stored on the work tool in its own data processing device and subsequently processed on a data processing device on which the method according to the invention is executed.

[0017] According to an advantageous embodiment of the invention, the determined speed is integrated over time to determine the distance traveled in the pipeline, so that the position of the working device within the pipeline can be determined by integrating from the start of its journey in the pipeline.

[0018] A data processing device comprising means for executing the computer-implemented method described above or below also represents a solution to the problem described at the outset. This typically electronic data processing device also benefits from the advantages described above or below arising from the application of the method according to the invention. The same applies to a computer program comprising instructions which, when the method is executed by a data processing device, in particular according to claim 8, cause the computer-implemented method according to any one of claims 1 to 7 or the method described above or below to be executed. This invention also benefits from the advantages described above or below. The same applies to a computer-readable medium on which the computer program according to claim 9 is stored.

[0019] The problem initially set out is also solved by a method for determining the state of a working device moving in a pipeline, in which first magnetic field data of a particularly remanent magnetic field of the pipeline are recorded by means of at least one first magnetic field sensor of the working device along a section of the pipeline, second magnetic field data of the magnetic field are recorded by means of at least one second magnetic field sensor of the working device arranged axially offset to the first magnetic field sensor by at least 30 cm in particular along the section, and subsequently at least one state of the working device is determined using the computer-implemented method described above or below and accordingly by means of a data processing device, in particular that according to claim 8.The data processing device of the work tool can be the one that carries out the computer-implemented method. However, it can also be a separate (electronic) data processing device to which the magnetic field data determined by the work tool is provided. These methods, which are implemented by and using the work tool and any separate data processing device, also offer the advantages described above or below. In particular, for subsequent analysis, the speeds and / or the distances or paths of the work tool determined in the data processing device are stored, possibly on the work tool itself, along with an associated time stamp. Thus, the speed of the work tool during its operation can also be analyzed later.

[0020] In general, during the execution of the computer-implemented method, in a further development of the invention, magnetic field data can also be recorded again for a new determination of the speed, i.e., the methods can run in parallel for the continuous determination of the speed at different positions.

[0021] In particular, magnetic field sensors (MFL sensors) or highly sensitive sensors are used as magnetic field sensors. When using MFL sensors, the first magnetic field data is generated from the data of a first MFL sensor array, and the second magnetic field data is generated from a further MFL sensor array spaced axially away from the first MFL sensor array. Alternatively or additionally, highly sensitive magnetic field sensors with a sensitivity of <3 mT, preferably <0.2 mT, are used to measure a remanent magnetic field.

[0022] In particular, the magnetic field sensors are oriented and designed to measure the axial magnetic field. This simplifies matching by eliminating the need to consider rotation of the working tool. Alternatively or additionally, the magnetic field sensors can measure the radial magnetic field, particularly in the form of two components angled relative to each other. In this case, the evaluation can advantageously take into account a rotation of the working tool, measured separately, for example, via a gyro sensor, particularly around its longitudinal axis.

[0023] According to a further development of the invention, by combining the gyro data with speed and time, an altitude profile or a

[0024] Preferably, the magnetic field data is acquired without contact, such that the magnetic field sensors are positioned away from the inner surface of the pipeline during the measurement, in particular if they are integrated into a central body of the working device or arranged directly on or in the surface of the central body. This applies particularly to highly sensitive magnetic field sensors, which are then arranged at a sufficient distance from the potentially biofilm-covered inner surface of a pipeline. A central body of the working device is one that, when positioned centrally in the pipeline, encompasses the longitudinal center axis of the pipeline, although in the radial direction it extends, in particular, only over a radius of a maximum of 50% of the pipeline radius.

[0025] According to a further development of the invention, the first and / or second magnetic field data can additionally be used to determine defects and / or installations in the pipeline. The former applies primarily to the use of MFL sensors, the latter applies particularly to the use of highly sensitive magnetic field sensors. It is understood that when using MFL sensors, the working device is additionally equipped for magnetizing the pipeline and has corresponding magnetizing units for this purpose.

[0026] The problem initially posed is also solved by a device for inspecting pipelines, in particular by a pipeline pig, which has at least two axially spaced magnetic field sensors and a data processing device as described above or below. In particular, the magnetic field sensors are designed as the previously described highly sensitive magnetic field sensors with a sensitivity <3 mT and preferably <0.2 mT. In particular, the magnetic field sensors are integrated into a central body of the device or arranged directly on or in its surface.

[0027] The speed, position and, in combination with other data, in particular the relative altitude, are determined as the state of the working device using the methods according to the invention.

[0028] Further advantages and details of the invention can be found in the following description of the figures. The schematic representation shows: Fig. 1 a diagram of a method according to the invention, Fig. 2 a view of another method according to the invention, Fig. 3 a view of a working device according to the invention in a pipeline, Fig. 4 the signal profiles of two magnetic field sensors of a working device according to the invention, Fig. 5 Measurement data: speed over time of a working device according to the invention, Fig. 6. Measurement data: distance over time of a working device according to the invention, Fig. 7 Measurement data: Altitude over distance of a working device according to the invention.

[0029] Individual technical features of the embodiments described below can also be combined with previously described embodiments and the features of one of the independent claims and any further claims to form articles according to the invention. Where appropriate, functionally equivalent elements are provided with identical reference numerals.

[0030] A computer-implemented method 40 according to the invention first comprises providing a first magnetic field sensor 22, which is arranged at the front end 23 of a working device 16 and measures a remanent magnetic field of a pipeline 18 over a section of the pipeline 18 ( Fig. 1 and Fig. 3) recorded magnetic field data. The magnetic field data of the pipeline 18, recorded during the movement of the working device 16 along the inner surface 38 of the pipeline 18, represent a signal profile of the remanent magnetic field of the pipeline 18. In particular, axial data of the magnetic field are recorded, i.e., the magnetic field is measured in the axial direction. In a step 60, the data from a second magnetic field sensor 22, which is arranged axially offset by a distance d at the rear end 25 of the working device 16, are provided.

[0031] The magnetic field data 3 recorded by the first magnetic field sensor 22 represent a first signal waveform of the remanent magnetic field along a section of the pipeline 18. In step 60, the second magnetic field data 5, recorded by a second magnetic field sensor of the working device, which is arranged axially offset from the first magnetic field sensor, are provided. The second magnetic field data 5 form a second signal waveform of the magnetic field recorded by the second magnetic field sensor 22. In step 70, the data are filtered to obtain only the low-frequency signal component between 1 Hz and 5 Hz. These signal components are then used to match the signal waveforms in step 80 using a Dynamic Time Warp algorithm, in particular a Fast Dynamic Time Warp algorithm, in order to assign similar signal waveforms to each other.From this, a time offset dt is determined, from which, in step 90, a velocity of the working device is determined in the axial direction, taking into account the known distance d between the magnetic field sensors 22. In step 100, the distance traveled by the working device 16 in the pipeline 18 is determined by integrating the velocity over time.

[0032] The method 40 according to the invention is, according to the exemplary embodiment, as described in the Fig. 2 is integrated into a further method according to the invention, which in a first step 10 includes the acquisition of magnetic field data 3 of the remanent magnetic field of the pipeline using the first magnetic field sensor 22, in a second method step includes the acquisition of second magnetic field data 5 of the magnetic field using the second magnetic field sensor 22, and in a third method step 30 includes the acquisition of further sensor data, for example, from a gyro sensor. The intervals between the individual method steps in the Fig. 1 and Fig. The two arrows arranged do not necessarily imply a chronological sequence of the process steps. It is understood that the data from the magnetic field sensors and other sensors are recorded simultaneously and automatically divided into sub-areas for evaluation by the algorithm.

[0033] Then, according to Fig. 2 the computer-implemented method according to Fig. 1. This process concludes with the determination of the distance traveled in step 100 and the determination of an altitude profile in process step 110, where the data from the gyro sensor are combined with the speed data to determine the altitude profile. Fig. The elevation profile shown in section 7 will be evaluated.

[0034] A working device according to the invention 16 ( Fig. 3) with direction of travel A has a central body 32, with the first magnetic field sensor 22 arranged at the front end 23. In the axial direction, i.e., in the normal orientation of the working device 16 while traveling through the pipeline in the direction of the longitudinal center axis 24 to the rear and according to the present Fig. With the central body 32 thus offset to the left, the second magnetic field sensor 22 is located at the rear end 25. Like the first magnetic field sensor, it is a highly sensitive sensor capable of measuring the remanent magnetic field of the pipeline. The magnetic field sensors 22 are integrated into the central body, which does not interfere with the remanent magnetic field of the pipeline 18. To space the central body 32 from the inside 38 of the pipeline 18, the central body has spacers 34 in the form of cups, which also ensure the propulsion of the working tool. In addition, individual centering arms (not shown) can hold the working tool 16 in the center of the pipeline.

[0035] The central body 32 also contains an electronic data processing device 26 according to the invention, which has conventional means of electronic data processing and is supplied with energy by an energy storage device 28. Additional sensors 42 for recording further inspection data, comprising at least one gyro sensor, which detects the orientation of the working device 16.

[0036] The signal waveforms of the axial magnetic field measured in mT, already filtered and recorded by the two magnetic field sensors 22, are shown in Fig. Figure 4 illustrates this. The algorithm used for matching determines a time offset dt, from which the speed v of the working device 16 is then determined using the distance d. In the Fig. Figure 5 shows the speed of the working device 16 recorded over the time measured by the working device. For validation of the invention, data from an odometer, i.e., a mechanical measuring device for determining speed, were also recorded in parallel. The speed profiles differ only marginally, if at all, which validates the speed determination according to the invention.

[0037] In the Fig. Figure 6 shows the distance traveled over time plotted on the y-axis. By combining the sensor data with the data from a gyro sensor, the altitude of the working device 16 relative to a zero point can be determined, thus representing the elevation profile of the pipeline 18. In this case, the pipeline has three longer, deep sections at depths of up to 30 m relative to the installation site.

Claims

[1] Computer-implemented method for determining the state of a working device (16) in a pipeline (18) designed for transporting fluids, comprising the steps: - Providing (50) first magnetic field data (3) of a particularly remanent magnetic field of the pipeline (18) recorded with at least one first magnetic field sensor of the working device (16), wherein the first magnetic field data form a first signal profile of the magnetic field measured by the first magnetic field sensor along a section of the pipeline (18), - Providing (60) second magnetic field data (5) of the magnetic field recorded by at least one second magnetic field sensor (22) of the working device (16) arranged axially offset to the first magnetic field sensor (22), wherein the second magnetic field data (5) form a second signal waveform of the magnetic field recorded by the second magnetic field sensor (22), - Matching (80) the first and second magnetic field data (3,5) with each other to determine a time offset (dt) of the signal waveforms, - Determining (90) a speed (v) of the working device (16) from the time offset (dt) and the distance (d) of the two magnetic field sensors. [2] Method according to claim 1, characterized by that the magnetic field data are frequency-filtered before matching to use low-frequency components [3] Method according to claim 2, characterized by , that an upper clipping limit for frequency filtering is 5 Hz and / or that a lower clipping limit for frequency filtering is 1 Hz. [4] Method according to any one of the preceding claims, characterized by , that a DTW algorithm is used for matching (80). [5] Method according to any one of the preceding claims, characterized by , that the velocity (v) is integrated over time to determine the distance traveled. [6] Method according to any one of the preceding claims, characterized by , that to provide the first magnetic field data (3) the magnetic field data of the MFL sensors of a first sensor ring are combined and / or that to provide the second magnetic field data (5) the magnetic field data of the MFL sensors of a second sensor ring are combined. [7] Method according to any one of the preceding claims 1 to 5, characterized by , that to provide the first magnetic field data (3) the magnetic field data of at least two highly sensitive first magnetic field sensors are combined and / or to provide the second magnetic field data the magnetic field data of at least two highly sensitive second magnetic field sensors are combined. [8] Data processing device comprising means for carrying out the method according to any one of the preceding claims 1 to 7. [9] Computer program comprising instructions which, when executed by a data processing device (26), cause the data processing device (26) to execute the method according to any one of claims 1 to 7. [10] Computer-readable medium on which the computer program according to claim 9 is stored. [11] Method for determining the state of a working device (16) moving in a pipeline (18), comprising recording (10) of first magnetic field data (3) of a particularly remanent magnetic field of the pipeline (18) by means of at least one first magnetic field sensor (22) of the working device (16) along a section of the pipeline (18), - a recording (20) of second magnetic field data of the magnetic field by means of at least one second magnetic field sensor (22) of the working device (16) arranged in the axial direction to the first magnetic field sensor (22) by in particular at least 30 cm along the section - Determining at least one state of the working device (16) by the method according to one of the preceding claims 1 to 7 using a data processing device (26) according to claim 8. [12] Method according to claim 11, characterized by , that the speed (v) and / or the distance is stored on the working device (16) in particular with an associated time date. [13] Method according to claim 11 or 12, characterized by , that MFL sensors are used as magnetic field sensors, in particular wherein the first are generated from data of a first MFL sensor ring and the second magnetic field data are generated via a further MFL sensor ring spaced axially away from the first MFL sensor ring. [14] Method according to any one of claims 11 to 13, characterized by , that highly sensitive magnetic field sensors with a sensitivity of less than 3 mT, preferably less than 0.2 mT, are used as magnetic field sensors (22). [15] Method according to any one of claims 11 to 14, characterized by , that the magnetic field sensors (22) measure the axial magnetic field. [16] Method according to any one of claims 11 to 15, characterized by , that the magnetic field sensors (22) measure the radial magnetic field in particular in the form of two components angled relative to each other. [17] Method according to any one of the preceding claims 11 to 16, characterized by , that the recording of the magnetic field data is carried out without contact in such a way that the magnetic field sensors (22) are removed from the inner surface (38) of the pipeline (18) during the measurement, in particular in that they are integrated into a central body (32) of the working device (16) or are arranged directly on or in the surface of the central body (32). [18] Method according to any one of the preceding claims 11 to 17, characterized by, that the first and / or second magnetic field data are used in addition to determining defects and / or installations of the pipeline (18). [19] Working device for inspecting pipelines, in particular pipeline pig, comprising at least two axially spaced magnetic field sensors (22) and a data processing device (26) according to claim 8. [20] Working tool according to claim 19, characterized by , that the magnetic field sensors (22), which are designed in particular as highly sensitive magnetic field sensors with a sensitivity of less than 3 mT, preferably less than 0.2 mT, and are spaced apart in the axial direction, are integrated into a central body (32) of the working device (16) or are arranged directly on or in its surface.

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