Method for detecting a change in status in an underwater system

Abstract

The invention relates to a method for detecting a change in status in an underwater system (100), a computer unit and a computer program for carrying out said method, and an underwater system. The underwater system comprises a plurality of underwater devices (200, 200-1 - 200-3), each including at least one actuator (20, 20-1 - 20-3) and at least one vibration sensor (10, 10-1 - 10-3). The method comprises the steps of receiving a signal of the vibration sensor (10, 10-1 - 10-3) from at least one of the plurality of underwater devices (200, 200-1 - 200-3), comparing the received signal with a reference signal of the vibration sensor (10, 10-1 - 10-3) for the at least one underwater device (200, 200-1 - 200-3), determining a deviation between the reference signal and the received signal, and detecting a change in status in the underwater system (200, 200-1 - 200-3) according to the determined deviation.

Description

[0001] Robert Bosch GmbH

[0002] R.405717 - Baumann

[0003] Method for detecting a change in state in an underwater system

[0004] Description

[0005] The present invention relates to a method for detecting a change in state in an underwater system, a computing unit and a computer program for carrying out the method, and an underwater system.

[0006] Background of the invention

[0007] Underwater systems, such as offshore oil or gas production facilities, comprise a multitude of piping systems in which process valves are used to control or shut off the flow of the fluid being pumped. Because such facilities operate at great depths at sea, their components are subject to severe stresses due to the environmental conditions. If these stresses lead to a malfunction, for example, of the process valves, significant damage can occur.

[0008] Disclosure of the invention

[0009] According to the invention, a method for detecting a change in state in an underwater system, a computing unit and a computer program for implementing the method, and an underwater system having the features of the independent patent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

[0010] The underwater system has a plurality of underwater devices, each containing at least one actuator and at least one vibration sensor. The underwater devices can be, for example, linear or rotary actuators for actuating process valves. These can in particular have an electric, electro-hydraulic and / or electro-pneumatic drive which includes an electric / electronic control system. Further examples of underwater devices are pumps and / or compressors, which can also include an electric / electronic control system. The at least one vibration sensor can be arranged within the respective underwater device and electrically connected to its control system so that the latter can receive signals from the vibration sensor. In particular, the vibration sensor is mounted on a circuit board, e.g. a main board (so-called main orMotherboard), the controller of the respective underwater device, or in an actuator. The underwater devices can be arranged at different positions in the underwater system, spaced from one another, and at least partially connected to one another, for example, via a cable system.

[0011] Vibration sensors can be used to monitor changes in the condition of such an underwater system, for example, to detect and prevent malfunctions of individual components at an early stage. Furthermore, they can be used to determine the actual opening positions, such as the opening cross-sections, of the process valves in the underwater system.

[0012] Specifically, in the method according to the invention, a signal from the vibration sensor of at least one of the plurality of underwater devices is received. The one signal (of an underwater device) or the multiple signals (from multiple underwater devices) can be received by a computing unit configured to evaluate the one or more vibration sensor signals and, in doing so, to perform frequency analyses, for example. The computing unit can be one or more controllers of the underwater devices and / or a separate computing unit. The signal from the vibration sensor of at least one of the plurality of underwater devices can be received continuously or at predetermined intervals for a predetermined period of time. The received one or more vibration sensor signals can be stored by the computing unit, e.g., for later analysis, etc.

[0013] The received signal is compared with a reference signal of the vibration sensor for the at least one underwater device. The reference signal can be a signal that the vibration sensor outputs in a predetermined reference state (e.g., valve open, valve closed, device fault-free, etc., see below) of the at least one underwater device. The reference signal can be determined based on a plurality of vibration sensor signals that were determined in the predetermined reference state. For example, the computing unit can comprise an (AI) model ("artificial intelligence") that is trained based on the plurality of vibration sensor signals in order to calculate the reference signal of the at least one underwater device. If the underwater device is, for example, a linear actuator for an underwater process valve, the reference state can be, for example,This can be a closed or fully open state of the process valve. It is also possible for a reference signal to be determined for a plurality of vibration sensors in a reference state of the entire underwater system. In this case, the reference state could be, for example, trouble-free operation of the underwater system.

[0014] During the comparison, a deviation between the reference signal and the received signal is determined. The deviation can be determined, for example, by determining a difference between a time-based signal received by the vibration sensor over a predetermined period of time and the reference signal. In this case, the deviation itself can represent a time-dependent signal whose amplitudes, frequencies, etc. can be evaluated. Alternatively or additionally, the vibration sensor signal and the reference signal can be transformed into the frequency domain, for example using a Fast Fourier Transformation (FFT), and the deviation can be determined, for example, based on an amplitude and / or frequency difference between the two signals. It is also possible for the deviation to be determined using so-called artificial intelligence (AI, i.e. a so-called machine learning method or machine pattern recognition method).For this purpose, the AI ​​can be trained with a large number of reference signals as well as with a large number of vibration sensor signals from previously detected state changes, which can be stored in a data memory. The trained AI can then determine a deviation of the received vibration sensor signal from the reference signal using pattern recognition.

[0015] Depending on the detected deviation, e.g., if a parameter (e.g., maximum amplitude, amplitude for specific frequencies or orders, etc.) of the detected deviation exceeds a predetermined threshold, a state change in the underwater system is detected. For example, if a maximum value of the difference between the time-based vibration sensor signal and the reference signal and / or the amplitude / frequency difference described above exceeds a predetermined threshold, a state change in the underwater system can be inferred.

[0016] According to one embodiment, a measure can be performed when a state change is detected. In particular, the computing unit can initiate / perform further steps / actions based on the detected state change in order to react to the state change. In this case, for example, information, such as an analog or digital signal, can be output to a higher-level controller.

[0017] According to one embodiment, a state change in the underwater system can occur by opening or closing an underwater process valve. For this purpose, at least one of the plurality of underwater devices can be configured to actuate an underwater process valve. As already described above, depending on the type of underwater process valve, this can be, for example, a linear or rotary actuator with which the underwater process valve can be opened and closed. In this case, the vibration sensor of the underwater device can also be attached to / in / on the linear or rotary actuator. During the opening and closing of the process valve, from a certain change in the opening position, which corresponds to a certain size of the opening cross-section, a significant change in volume flow through the process valve and in a line connected to it occurs. This change in volume flow triggers a change in vibration (e.g.B. a noise) which can be mechanically transmitted and detected by the vibration sensor. In other words, at a point in time after the actuator has been activated, a volume flow is released through the process valve (start of opening of the process valve), reaches a plateau (end of opening of the process valve), begins to decrease (start of closing of the process valve) or ends (end of closing of the process valve), whereby a state of the underwater device is changed. The vibration change triggered in each case can be detected by means of the deviation of the vibration sensor signal from its reference signal. Intermediate positions can also be detectable depending on the noise development.

[0018] According to one embodiment, the measure that can be carried out when a change in state is detected can be determining an opening position of the underwater process valve during opening or closing, wherein the determination is carried out using a signal from the vibration sensor of the at least one underwater device for actuating the underwater process valve. In one embodiment, upon detection of the start of opening and / or closing of a process valve, for example, a signal from the vibration sensor of the underwater device can be received for a predetermined time and / or until the end of opening or closing is detected and compared with its reference signal. This means that after detecting a first change in state, namely here the start of opening or closing of the process valve, the vibration sensor signal continues to be recorded and compared with the reference signal.The predetermined time during which the vibration sensor signal continues to be recorded can be determined, for example, based on previously determined opening and closing times of the process valve. The predetermined time can be selected to be longer than the previously determined opening and closing times of the process valve in order to reliably detect / record the vibration signal throughout an entire opening or closing process. Intermediate positions can be temporally interpolated based on a detected start and end position, or based on a start position and opening or closing times.

[0019] Furthermore, the vibration sensor signal of the underwater device can be compared, for example, with an opening position sensor of the process valve. For example, the beginning of the process valve's opening can be determined by the deviation of the vibration sensor signal from the reference signal, detected as a change in state, and assigned to a corresponding opening position indicator of the opening position sensor. Similarly, a fully open process valve can be assigned to a corresponding opening position indicator of the opening position sensor. Using a characteristic curve of the process valve, which depicts a relationship between the opening cross-section (position) and the volume flow through the valve, the flow through the process valve can also be determined directly from the vibration sensor signals.

[0020] According to one embodiment, a change in state in the underwater system can occur due to the occurrence of an anomaly in at least one of the plurality of underwater devices. This can be caused, for example, by a defect in an underwater device or by a change in a line cross-section due to a malfunction / defect in the line system. The change in the line cross-section, or the associated flow change, can lead to a change in vibration in the line system, which can be detected by a mechanical coupling / connection of the plurality of underwater devices to the line system or by sound waves from their vibration sensors.

[0021] In addition, wear on the underwater process valve can be determined as a measure to be taken based on the comparison between the vibration sensor signal and the reference signal. For this purpose, a large number of opening and closing processes of the underwater process valve can be monitored using the vibration sensor signal of its underwater device. In particular, the deviations of the vibration sensor signal from its reference signal can be recorded during each opening and closing process, and changes in the deviations can be determined. These changes can, for example, indicate wear on the edges of the process valve and represent a measure of wear. If a change in the deviation of the vibration sensor signal from its reference signal during an opening or closing process exceeds a predetermined value, a defect in the process valve can be concluded, for example.

[0022] According to one embodiment, the measure that can be carried out when a change in state is detected can be a determination of a position of the anomaly in the underwater system using signals from the vibration sensors of more than one of the plurality of underwater devices. A position of the anomaly is to be understood as a position / location / component from which an increased vibration emanates, which can be detected by the vibration sensors of the plurality of underwater devices. In particular, vibration sensor signals from a plurality of spaced-apart underwater devices of the underwater system can be analyzed if, for example, it is detected at one of the underwater devices that a deviation of the vibration sensor signal from the reference signal indicates an anomaly.For this purpose, deviations of all vibration sensor signals from their reference signals can be determined and a cause of the change in state can be detected by comparing the individual deviations determined.

[0023] According to one embodiment, the position of the anomaly can be determined by determining time intervals between vibration sensor signals, e.g., between characteristic values ​​of the vibration sensor signals. Such characteristic values ​​can, for example, be a maximum value of the determined deviation if this was determined on a time-based basis. According to one embodiment, a frequency analysis can alternatively or additionally be performed to determine the characteristic value of the individual determined deviations. The vibration sensor signal and the reference signal can be transformed into the frequency domain, e.g., using a Fast Fourier Transformation (FFT). The characteristic value can then, for example, be a maximum amplitude of the deviation between the reference signal and the vibration sensor signal.This can be assigned to a specific frequency, which can be the same for all analyzed vibration sensor signals from the first and the additional underwater systems, although the time at which the maximum amplitude occurs and its value can vary. Using the time intervals between the maximum amplitudes of the vibration sensor signals from the first and the additional underwater devices, the location of the fault / defect can be determined based on known cable lengths and the speed of sound between the underwater devices in the underwater system.

[0024] In addition to the time intervals between the maximum amplitudes of the vibration sensor signals, the amplitude values ​​can also be taken into account to determine the location of the fault. The frequency at which the maximum amplitudes of the vibration sensor signals of all underwater devices occur can also be used to determine the nature of the fault / defect. This information can be sent, for example, to an output unit of the underwater system to initiate troubleshooting by a user.

[0025] A computing unit according to the invention, e.g. a controller of an underwater device or an underwater control master, is configured, in particular in terms of programming, to carry out a method according to the invention.

[0026] Implementing a method according to the invention in the form of a computer program or computer program product with program code for performing all method steps is also advantageous, as this entails particularly low costs, especially if an executing control unit is also used for additional tasks and is therefore already present. Suitable data storage devices for providing the computer program include, in particular, magnetic, optical, and electrical storage devices, such as hard disks, flash memories, EEPROMs, DVDs, and others. Downloading a program via computer networks (Internet, intranet, etc.) is also possible.

[0027] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0028] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0029] The invention is illustrated schematically in the drawings using exemplary embodiments and is described in detail below with reference to the drawings.

[0030] Character description

[0031] Figures 1a to 1c schematically show an example of a determination of an opening process of an underwater process valve according to an embodiment of the invention.

[0032] Figure 2 schematically shows an example of a structure of an underwater system in which a cause for a change in state can be detected according to another embodiment of the invention.

[0033] Detailed description of the drawings

[0034] Figures 1a to 1c schematically show an example of determining an opening process of an underwater process valve 40 according to an embodiment of the invention. The underwater process valve 40 is connected to an underwater device 200, which includes an actuator 20 with a disk 30 and a vibration sensor 20.

[0035] In Figure 1a, an opening cross-section of the process valve 40 is closed by the disc 30, so that no flow (indicated by the arrow in Figure 1a) flows through the process valve 40. The vibration sensor 10 of the underwater device 200, which is attached to / in / on the actuator 20, measures vibrations 10a, 10b, 10c applied to the actuator 20. When the process valve 40 is closed, the actuator 20 is exposed to a fundamental vibration 10a of a line system (not shown) to which the process valve 40 and the underwater device 20 are mechanically connected. This fundamental vibration 10a is detected by the vibration sensor 10 and can serve as a reference signal to detect changes in the state of the process valve 40 based on vibration changes.

[0036] If the process valve 40 is opened (Figure 1b), an incipient flow (indicated by the thin arrows in Figure 1b) through the process valve 40 triggers a change in vibration (e.g., an increase in vibration amplitude), which is detected by the vibration sensor 10. Based on a characteristic of the now detected vibration 10b in comparison to the fundamental vibration 10a (deviation between the reference signal and the received signal), the beginning of the opening of the process valve 40 can be detected as a change in state.

[0037] Figure 1c shows the process valve 40 in a fully open state, with the entire flow (indicated by three identical arrows) flowing through the process valve 40. The increased flow through the process valve 40 further changes the vibrations to which the actuator 20 is exposed, so that the fully open position of the process valve can be determined as a further change in state based on the changed vibration characteristic 10c by means of the vibration sensor 10. Since the vibrations acting on the actuator 20, which are detected by the vibration sensor 10, change continuously from the beginning of opening until the process valve 40 is fully opened, the position of the disc 30 during the opening process can be determined using the vibration sensor signal.

[0038] It is understood that the described effects occur in reverse order during a closing process of the process valve 40 and can therefore be detected in the same way.

[0039] Figure 2 schematically shows an example of a structure of an underwater system 100 in which a cause for a state change can be detected according to another embodiment of the invention. The underwater system 100 shown comprises three exemplary power systems pi, P2, ps, to which the underwater devices 200-1, 200-3, 200-3 with the actuators 20-1, 20-2, 20-3 and the vibration sensors 10-1, 10-2, 10-3 are connected via mechanical couplings Ci, C2, C3 (not shown in detail).

[0040] In the underwater system 100, a disturbance occurs at a position E of the line system pi (indicated by the exploded symbol). This disturbance can lead to a vibration change 10d in the line system pi, which can be transmitted to the line system pi via the mechanical coupling Ci of the underwater device 200-1 or to the vibration sensor 10-1 via sound waves. In the example shown, the sensor detects the vibration change 10d (deviation between a reference signal of the vibration sensor 10-1 and the received signal) at a time ti.

[0041] Since the line system p1 is connected to the other line systems p2, p3, the vibration change 10d is also detected by the vibration sensors 10-2, 10-3 of the other underwater devices 200-2, 200-3. However, due to the different line lengths, these detect the vibration change at later times t2, ts. The times t1, t2, ts at which the vibration change was detected by the vibration sensors 10-1, 10-2, 10-3 can be stored as a time stamp in a computing unit, which can be, for example, a controller of the underwater devices and / or an underwater control master. Based on the time intervals between the individual times t1, t2, ts and the known line lengths of the line systems p1, p2, p3, the position E of the disturbance can then be calculated.Due to the increased speed of sound underwater, the described method can also be used to detect disturbances in neighboring underwater systems.

Claims

Claims 1. A method for detecting a change in state in an underwater system (100) comprising a plurality of underwater devices (200, 200-1 - 200-3), each containing at least one actuator (20, 20-1 - 20-3) and at least one vibration sensor (10, 10-1 - 10-3), comprising the steps: - receiving a signal from the vibration sensor (10, 10-1 - 10-3) of at least one of the plurality of underwater devices (200, 200-1 - 200-3); - comparing the received signal with a reference signal of the vibration sensor (10, 10-1 - 10-3) for the at least one underwater device (200, 200-1 - 200-3); - Determining a deviation between the reference signal and the received signal; and - Detecting a change in state in the underwater system (200, 200-1 - 200-3), depending on the detected deviation.

2. The method according to claim 1, wherein an action is taken when a change in state is detected.

3. Method according to one of the preceding claims, wherein at least one of the plurality of underwater devices (200, 200-1 - 200-3) is configured to actuate an underwater process valve (40), and a change of state in the underwater system occurs by opening or closing the underwater process valve.

4. The method according to claim 2 and 3, wherein the measure is a determination of a current opening position of the underwater process valve (40) during the opening and / or closing by means of the signal of the vibration sensor of the at least one underwater device for actuating the underwater process valve (40).

5. A method according to any one of the preceding claims, wherein a change in state in the underwater system occurs due to an occurrence of an anomaly in at least one of the plurality of underwater devices.

6. The method of claim 5, wherein the action is determining a position of the anomaly in the underwater system using signals from the vibration sensors of more than one of the plurality of underwater devices.

7. The method of claim 6, wherein the position of the anomaly is determined by determining time intervals between characteristic values ​​of the vibration sensor signals.

8. Computing unit configured to carry out a method according to one of the preceding claims.

9. A computer program which causes a computing unit to carry out a method according to any one of claims 1 to 7 when executed on the computing unit.

10. A machine-readable storage medium having a computer program according to claim 9 stored thereon.

11. An underwater system comprising a plurality of underwater devices (200, 200-1 - 200-3), each containing at least one actuator (20, 20-1 - 20-3) and at least one vibration sensor (10, 10-1 - 10-3), at least one line system (pi, p2, pa) to which the plurality of underwater devices (200, 200-1 - 200-3) are connected; and a computing unit according to claim 8.

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