Method for a sensor-based monitoring of at least one rotating work machine

Abstract

The invention relates to a method for monitoring at least one rotating work machine, in particular a centrifugal pump, comprising at least one sensor for detecting at least one measurement parameter which relates to the operation of the work machine and comprising a central analysis unit which is communicatively connected to the at least one sensor. The method has the steps of transmitting at least one measurement value and / or a measurement value which is pre-processed by the sensor to the central analysis unit by means of the sensor, analyzing the at least one measurement value and / or the pre-processed measurement value by means of the analysis unit, and generating at least one command for a dynamic remote configuration of the sensor behavior of the at least one sensor on the basis of the analysis result and transmitting the command from the analysis unit to the at least one sensor.

Description

[0001] Description

[0002] Method for sensor-based monitoring of at least one rotating machine

[0003] The invention relates to a method for monitoring at least one rotating working machine, in particular a centrifugal pump, comprising at least one sensor for detecting at least one measurement parameter relating to the operation of the working machine, as well as a central evaluation unit which is communicatively connected to the at least one sensor.

[0004] Automated condition monitoring of work machines, especially rotating machines, is already well known. For this purpose, one or more sensors are mounted near or on the machine to be monitored. The measured values ​​from the sensors are recorded cyclically and then transmitted directly or after preprocessing in the sensor to a cloud or another device.

[0005] Machine monitoring is usually coupled with an automatic alarm system designed to warn the operator of the machine or system as quickly and reliably as possible when critical conditions occur. To reliably record and detect critical conditions in machines with dynamic operating behavior, it is often necessary to perform measurements with short measuring intervals. This is the only way to ensure that a critical condition can be recorded and detected by a single measurement. A similar problem exists when monitoring machines that operate on short cycles. Ideally, measurements should be taken at times when the machines are actually active. If, instead, measured values ​​are recorded when the machine is switched off, efficient monitoring is not possible.

[0006] However, a continuous monitoring measurement carried out at short time intervals is energetically unreasonable and cannot be carried out sensibly, especially in solutions with battery-operated sensors, since the short measuring intervals and the resulting high-frequency data transmission to a central evaluation unit result in an enormous energy requirement, which significantly shortens the battery life.

[0007] Another problem is the influence of the machine environment on the measured values.

[0008] If the machines to be monitored are part of a large system, vibrations, noise from neighboring machines, etc., can distort the measured values ​​and trigger false detection. It is desirable to filter out such influences as effectively as possible to avoid false alarms.

[0009] The present invention therefore addresses the problem of optimizing existing sensor-based monitoring methods, in which there is a data exchange between the sensor and the central evaluation unit, so that they can be carried out more efficiently, faster and also more energy-efficiently.

[0010] This object is achieved by a method according to the features of claim 1. Advantageous embodiments of the method are the subject of the dependent claims.

[0011] According to the invention, a dynamic remote configuration of the sensor behavior is carried out by means of the central evaluation unit. Remote configuration of the sensor behavior is understood to mean the adaptation of the sensor operation or any operating parameters of the sensor that affect or influence the measured value acquisition and the measured value evaluation. In this context, a sensor is understood not only to be the pure measured value pickup, but also a sensor controller or other unit for preprocessing and / or evaluating the measured values. Furthermore, the sensor can be equipped with an integral communication module for communication with the central evaluation unit or can be communicatively connected to an external communication device for indirect communication with the evaluation unit.Data communication between the evaluation unit and the sensor can take place via at least one intermediate node, in particular a gateway installed in the immediate reception range of the sensor. The gateway can preferably have an intermediate buffer for the temporary storage of communication data to be exchanged between the sensor and the evaluation unit. The at least one sensor can retrieve the temporarily stored data in the gateway as needed.

[0012] The transmission of the command from the evaluation unit can be done by sending the command from the evaluation unit to the sensor or alternatively by the sensor retrieving the command from the evaluation unit.

[0013] Dynamic remote configuration of the sensor is a necessary prerequisite for optimizing the sensor's measurement operation and evaluation process during ongoing machine monitoring, taking previous measured value evaluations into account. This allows the entire measurement process and monitoring to be dynamically adapted to the actual conditions. Overall, faster, more reliable, and more energy-efficient monitoring can be achieved.

[0014] To carry out the process, at least one recorded measured value and / or a measured value pre-processed on the sensor side must first be transmitted by the sensor to the central evaluation unit. The received measured value or the pre-processed measured value is then evaluated on the evaluation unit side and, depending on the evaluation result, a command for the dynamic remote configuration of the sensor behavior of at least one sensor is generated and transmitted to the sensor for remote configuration. For example, it is possible to trigger at least one repeat measurement on the sensor side using the command. A repeat measurement is understood to be a measurement that is carried out shortly after the receipt and evaluation of a previous measured value in order to be able to verify the previous measurement. Depending on the application, the repeat measurement must be carried out as soon as possible after the first measurement, in particular within a few seconds, e.g.less than 60 seconds after the measurement to be verified, ideally after 30 seconds or less. It is also conceivable that the command not only triggers a repeat measurement, but also allows the number of repeat measurements to be configured or the time interval between at least two consecutive repeat measurements to be remotely adjustable. Upon receipt of such a command, the received configuration for the process flow of a repeat measurement is implemented on the sensor side.

[0015] It is also conceivable that a specific threshold for internal sensor monitoring is configured using the command. Upon receipt of the corresponding command with at least one threshold, the sensor executes the corresponding process steps for threshold monitoring, for example, by comparing the currently recorded measured value against the remotely configured threshold or another sensor operating parameter against the remotely configured threshold. If the threshold is exceeded, at least one follow-up action can be triggered.

[0016] Threshold monitoring can be used primarily for error detection. For example, if the configurable threshold is exceeded, the sensor can enter an alarm state and / or generate and issue an alarm message. It is also conceivable that exceeding the threshold could trigger at least one repeat measurement to verify the previous measurement by repeating the measurement.

[0017] It is also conceivable that exceeding the threshold could trigger data communication between the sensor and the central evaluation unit or another communication partner. This ensures that only relevant measured values ​​are transmitted to the evaluation unit, which reduces overall energy consumption due to the reduced communication time.

[0018] It is also conceivable for the sensor to comprise two or more, particularly different, sensors. The sensors can record the same measured value for diversity reasons. However, it is also conceivable for the sensors to record different measurement parameters. A command from the central evaluation unit can be used to switch between sensors or to change the redundancy or diversity during measurement. In principle, it is possible to selectively deactivate or activate one or more sensors.

[0019] Furthermore, it is conceivable that the sensor could be put into a sleep or low-power mode using the command. In such a sleep or low-power mode, for example, the measurement data acquisition would be completely deactivated or reduced to a minimum in order to temporarily reduce the sensor's energy consumption to a minimum. Of course, the sensor could also operate at a reduced measurement frequency and / or sampling rate, etc., during low-power mode.

[0020] It is also conceivable that data communication between the sensor and the central evaluation unit is completely interrupted or at least reduced to a minimum during sleep or low-power mode. Using this command, such a sleep or low-power phase can not only be actively triggered, but the duration of such a sleep or low-power phase can also be specified.

[0021] According to an advantageous embodiment, the type of measured value acquisition in the sensor can be configured using the command generated by the central evaluation unit. This concerns, for example, a sampling rate and / or the measurement duration of an individual measurement by the sensor's sensor. Remote configuration of the sensor's internal preprocessing of the measured values ​​is also possible, i.e., it can be configured, for example, to summarize the measured values ​​of a measurement series and only communicate the mean value of the measurement series to the evaluation unit. Preferably, the data size of the measured or raw data to be transmitted can be configured using the command.

[0022] In principle, the method according to the invention can be applied to any type of measured value. As an example, the application to the measurement and monitoring of mechanical vibrations in rotating machines is mentioned here. The method is also particularly preferred for temperature measurement or temperature monitoring. It is particularly preferred for vibration monitoring supplemented by temperature measurement or temperature monitoring. If the remotely configurable sensor is suitable for detecting mechanical vibrations, the vibration axes to be measured can be adjusted or deactivated / activated, preferably via remote configuration. Furthermore, remote configuration of the cutoff frequency is useful.

[0023] It is also advantageous if the at least one sensor is a battery-operated sensor. Data communication between the sensor and the central evaluation unit preferably takes place via a radio connection, whereby any data transmission standard can be used. Remote configuration of the sensor operation is particularly advantageous for battery-operated sensors in order to optimize sensor operation with regard to energy consumption and to guarantee the longest possible battery life while maintaining sufficient measurement accuracy and reliability.

[0024] According to a preferred embodiment of the method, it can be provided that the sensor initially goes into a first sleep mode after sending the one or more measured values ​​to the central evaluation unit. During such a first sleep mode, the energy consumption of the sensor is reduced to a minimum, for example by stopping data communication with the central evaluation unit and / or measured value recording during the sleep mode. After the first sleep mode has ended, the sensor can receive at least one command from the evaluation unit and / or carry out an internal sensor evaluation of the previously recorded measurement data. The duration of the first sleep mode is selected such that the sensor is woken up in time to receive the command from the central evaluation unit and that activation of the data communication for command reception is ensured. The necessary process time for the measured value evaluation on the evaluation unit side is known orcan be easily estimated, so that the duration of the first sleep mode can be adapted to this process duration.

[0025] If data communication between the evaluation unit and the sensor takes place indirectly via an intermediate unit, particularly a gateway, it is possible to temporarily store any data packets, particularly commands, in the gateway and make them available for retrieval by the sensor. In this case, the duration of sleep mode can be designed more flexibly, since the sensor can retrieve the data sent to it from the gateway as needed, i.e., by individually selecting the sleep duration.

[0026] Depending on the evaluation result, a decision can then be made as to whether a repeat measurement should be carried out. This decision is preferably made in the evaluation unit, but decision-making within the sensor is also conceivable if internal evaluation of the measured values ​​is planned. If the evaluation is carried out by the central evaluation unit, the decision as to whether a repeat measurement should be carried out is also made in the evaluation unit, which is then initiated via remote configuration of the sensor. If, on the other hand, the measured values ​​are evaluated internally in the sensor, a corresponding decision to carry out repeat measurements can also be made internally in the sensor. If the previous measurement and at least one repeat measurement produce consistent or at least comparable results, the measurement is considered verified and is taken into account when deciding on any follow-up measures, e.g.for error detection and, if necessary, alarm.

[0027] It is also conceivable that the number of repeat measurements to be performed could be remotely configured via the central evaluation unit. Multiple repeat measurements can thus be advantageous in increasing the available data volume and improving the quality of data evaluation and condition detection of the machine. If, after the procedure has been completed, it is determined that a repeat measurement is not necessary, the sensor is preferably placed in a second sleep mode, in which neither measured values ​​are recorded nor data is transmitted to the central evaluation unit. The duration of the second sleep mode can be defined as significantly longer than the duration of the first sleep mode.

[0028] According to a further embodiment of the invention, the sensor can acquire measured values ​​at a first measuring interval in a first operating mode. In the first operating mode, the acquired measured values ​​are transmitted to the central evaluation unit via the communication channel after each measurement. The evaluation unit receives the measured values ​​and evaluates the received measured values ​​belonging to a series of measurements. Depending on the evaluation result, the central evaluation unit can initiate the sensor to operate in a second operating mode.

[0029] It is conceivable, for example, that the evaluation unit determines at least one detection threshold by evaluating the series of measurements and transmits this to the sensor. Using such a detection threshold, it might be possible, for example, to differentiate between different machine states, in particular whether the machine is currently in operation or in a rest phase.

[0030] It is preferred, for example, if the sensor records measurements with a second measuring interval in the second mode of operation, wherein the second measuring interval is selected to be shorter, in particular by at least a factor of 5, preferably 10, than the first measuring interval. Furthermore, it is provided that during the second mode of operation no measurement data is transmitted to the evaluation unit or at least less data is transmitted to the central evaluation unit than in the first mode of operation. The second mode of operation is particularly advantageous for monitoring machines with short cycles, since the shortened measuring interval ensures that measured values ​​can also be recorded during active operation of the machine. In return, the increased energy requirement due to the shortened measuring interval is compensated for by the interrupted or reduced data communication with the central evaluation unit.

[0031] During the second operating mode, the acquired measured values ​​are preferably compared within the sensor against a detection threshold, in particular the detection threshold previously determined by the evaluation unit. If the detection threshold is exceeded, the sensor switches to the first operating mode to continuously transmit the acquired measured values ​​to the central evaluation unit.

[0032] The sensor preferably returns to the second mode of operation if the measured values ​​fall below the detection threshold again.

[0033] It is particularly advantageous if the detection threshold allows a distinction between an active and inactive machine state. Defining such a detection threshold ensures that the sensor only transmits measurement data to the central evaluation unit if it has previously been determined based on the measurement data that the machine is in operation.

[0034] This approach is particularly preferred for sensors used to measure mechanical vibrations, because the amplitude of the detected vibration already provides an indication of whether the machine is in operation or is instead in a resting state.

[0035] In addition to the method according to the invention, the present invention also relates to a system comprising at least one central evaluation unit, in particular a cloud-based evaluation unit, and at least one sensor, wherein the evaluation unit and sensor are configured to carry out the method of the invention described above. The system can additionally comprise an intermediate gateway. In addition to the overall system, the invention also relates to a sensor for such a system, wherein the sensor is configured to be dynamically remotely configured by a central evaluation unit. Finally, the invention also relates to the central evaluation unit for a system according to the invention, wherein the central evaluation unit is configured to generate and transmit a command for the dynamic remote configuration of a communicatively connected sensor based on the evaluation result of one or more measured values.

[0036] The system, the sensor and the central evaluation unit thus have the same advantages and properties as have already been shown above using the method according to the invention, so that a repeated description is omitted at this point.

[0037] Further advantages and properties of the method will be demonstrated in more detail below using various embodiments that implement the invention. They show:

[0038] Fig. 1 : a flow diagram of a sensor device with repeated measurements,

[0039] Fig. 2: a conventional timing diagram for short-running machines with sensor,

[0040] Fig. 3: the corresponding flow chart according to the invention for intelligent detection of the pump state by the sensor device.

[0041] The method according to the invention is applicable to all machines that are to be monitored by sensors, in particular battery-operated sensors. One or more sensors are mounted close to the machine to be monitored, e.g., a pump, in particular a centrifugal pump, for condition monitoring purposes. The measured values ​​from the sensors are automatically recorded cyclically and then sent directly or after preprocessing in the sensor to a central evaluation unit, in particular to a cloud-based solution of the evaluation unit or to another device. For machine monitoring, at least one sensor for detecting mechanical vibrations can be used, for example. The sensor, in particular a battery-operated sensor, comprises an integral communication module that enables data exchange between the sensor and the central evaluation unit.Especially for larger systems with a large number of machines to be monitored, especially pumps, it is recommended to use a gateway that is installed near the machine and connected to the numerous sensors. The signals received from the sensors via a wireless standard are then communicated by the gateway to the cloud-based evaluation unit via an internet connection.

[0042] Machine monitoring is usually coupled with an automatic alarm system designed to warn the operator of the machine or system as quickly and reliably as possible when critical conditions occur. The invention aims to significantly increase the reliability of such alarm notifications. Another important goal is to improve the accuracy of the associated operating hours counter. By dynamizing both the measurement intervals and the measurement behavior of the sensors used, more precise statements about the condition of the monitored machines can be made in an energy-efficient manner. There are various specific applications for this, which are described in more detail below.

[0043] A key feature of this invention is the ability to dynamically change the sensor's behavior from the central evaluation unit, i.e., the cloud, without requiring any significant additional energy consumption. One way to control the sensor's behavior could work, as shown in Fig. 1:

[0044] A sensor first records measurement data during machine operation, such as mechanical vibrations and / or temperature values ​​in the vicinity of the machine to be monitored, and subjects the data to preprocessing and preliminary evaluation (block 10). The sensor then sends the measurement data or the preprocessed data to the cloud (block 20). The sensor then enters a "short-term sleep mode" (block 30) for a short time (e.g., 30 seconds) to save energy. Based on the current sensor data and sensor data from the past of the same sensor, the desired future behavior of the sensor is automatically determined in the cloud (reference numeral 40). This calculation or evaluation takes place on cloud-based servers in a very short computing time and can include, for example, comparing the received sensor value with a stored threshold value.Likewise, an alarm message can be generated on the cloud side depending on the evaluation result (Block 45), whereby this is preferably initially only stored temporarily and instead a repeat measurement is requested by the sensor to verify the alarm status.

[0045] The cloud now sends the desired sensor behavior back to the sensor as a response, and the sensor receives the command(s) for internally adjusting the sensor behavior (block 50). Due to the short processing time in the cloud, it is guaranteed that the result is available before the sensor's "short-term sleep mode" ends. If there is a gateway on the communication path between the sensor and the cloud (which transmits data in both directions), this gateway can receive and buffer the response intended for the sensor from the cloud. As soon as the sensor returns from "short-term sleep mode," the sensor retrieves the instructions for its further behavior either a) directly from the cloud or b) from the gateway, which had buffered the information intended for the sensor from the cloud.

[0046] In case b), this process is significantly faster and thus more energy-efficient than in case a). Based on the response received from the cloud, the sensor adapts its desired future operation (block 50). Using remote configuration, a repeat measurement can then be triggered in the sensor, for example, and its execution can be configured (block 60).

[0047] If it is decided in block 60 that the sensor does not perform a repeat measurement because the sensor value is, for example, below the limit value:

[0048] The sensor returns - without further action - to a normal (longer) sleep mode (block 70), e.g. more than 60 minutes, in particular 120 minutes or longer, since the available data does not require any special interaction;

[0049] If at least one repeat measurement is to be performed in block 60, either by command from the cloud or by sensor-internal evaluation, the execution can take place according to specifications from the cloud, for example, as follows: a. The sensor immediately performs a repeat measurement (and also transmits the data directly back to the cloud); b. The sensor performs several repeat measurements at shorter intervals; c. The sensor changes the type of data acquisition (e.g., in the case of vibration measurements: sampling rate, cutoff frequency, measurement duration, selection of the vibration axes, type of data preprocessing, size of the transmitted raw data) and repeats the measurement with changed data acquisition; d. The sensor activates a different measuring sensor (e.g., switching to acoustic measurement via microphone) and performs the repeat measurement with an alternative measuring sensor.

[0050] If the alarm condition is confirmed by at least one repeat measurement (repeated exceedance of the limit value), the alarm message can then also be issued (Block 45).

[0051] Summary:

[0052] After each data transfer to the cloud, the sensor will also receive a response from the cloud. It retrieves this response within a predefined short time slot. It thus dynamically checks which behavior it should currently adopt. Essentially, this allows both the measurement frequency and the sensor's operating mode to be dynamically changed. The sensor's behavior is thus actively controlled from the cloud without requiring a significantly higher energy consumption.

[0053] In the following, we will discuss in more detail the implementation of repeated measurements and their importance in machine monitoring.

[0054] Performing repeated measurements in machine monitoring is particularly useful where monitoring is carried out by comparing one or more sensor values ​​against assigned limit values, and where external influences can influence the sensor values ​​due to the machine environment. Many machines, such as pumps, have important elements that need to be monitored by appropriate sensors in order to receive an early warning before a failure (e.g., the bearings of a pump). Sensors here record the physical parameters, such as vibration, pressure, or temperature. Consequently, sensible limit values ​​are defined for each of these physical parameters; exceeding these values ​​indicates a critical condition (e.g., maximum bearing temperature). The monitoring of the set limit value of a parameter can take place either "on the edge" (i.e., in the sensor or HoT device itself) or alternatively in the cloud.Due to its greater flexibility and virtually unlimited computing power, the cloud is preferable.

[0055] If a current limit value is exceeded, a notification should generally be issued in the form of an alarm message (Fig. 1, Block 45) in order to prevent consequential damage to the machine or to the process (due to machine failure). However, many physical parameters are influenced not only by the operation of the machine, but also by its environment. Therefore, a measured value from a sensor does not always indicate the actual machine status. For example, connected pipes can induce external vibrations into a pump; likewise, starting or stopping the machine, as well as other temporarily occurring events, can lead to briefly high, but non-critical, vibration values. These non-critical events should be masked accordingly to avoid false alarms. On the other hand, in the case of actually high vibration values, e.g.If damage to the machine itself suddenly occurs, an alarm must be triggered as quickly as possible so that targeted countermeasures can be initiated promptly. This is important to prevent costly consequential damage as much as possible.

[0056] The purpose of repeated measurements is to quickly and reliably distinguish a non-critical temporary short-term event from a suddenly occurring critical event.

[0057] With a conventionally wired sensor, the measured value could simply be queried again to increase its evidence. However, in the case of battery-operated sensors, which are frequently used in HoT environments, the sensor usually automatically switches back to "sleep mode" immediately after transmitting the measurement data to save energy and thus achieve the longest possible battery life. The next measurement is then often only taken hours later (as scheduled). Using the dynamic remote configuration process, one or more repeated measurements can now be performed energy-efficiently even with battery-operated sensors or HoT devices in the event of a limit value being exceeded, while the additional energy required for this is reduced to a minimum.

[0058] If the evaluated data indicates an alarm, this alarm status is initially buffered internally (block 45). The cloud, or alternatively the HoT device itself, then immediately initiates one or more repeat measurements (block 60) to improve the evidence of the individual measured value. If the new measured values ​​confirm the previously determined indication for an alarm, then this alarm message is actually issued (block 45). Otherwise, however—i.e., in the case of non-critical repeat measurements—the first measured value is considered a fault triggered by a one-time, external event. In this case, the buffered alarm status is immediately deleted, and no message is issued. of the machine condition of short-cycle machines

[0059] This application is particularly advantageous for machines that are typically only switched on for short cycles. For example, there are pumps that only run for a few minutes to empty a container, but then are switched off for a long time. If the container fills very slowly, the pump's off-time will even exceed its on-time by several times.

[0060] If a battery-powered sensor is used on such a machine, continuous monitoring is only possible to a limited extent. To achieve a long battery life, the battery-powered sensor only records individual measurements at longer intervals (e.g., hourly). Between measurements, the sensor then goes into sleep mode to save energy. In sleep mode, neither measurements nor data transmission take place.

[0061] Fig. 2 shows a conventional time sequence for a machine that is switched on (multiple times) for a short period of time. The solid line 1 symbolizes the machine state, which changes between an off and on state. The measured values ​​to be monitored are recorded in a timer-triggered manner with cyclical repetition, which is indicated by arrows 2. The upper, dashed arrow 3 represents the data transmission of the sensor data to the cloud-based evaluation unit.

[0062] Fig. 2 shows that sensor data is very frequently recorded and transmitted when the machine is switched off. In contrast, measured values ​​are only occasionally acquired when it is switched on. Depending on how often and for how long the machine is actually running, this may lead to insufficient monitoring of the machine, as relevant critical conditions are only ever expected when the machine is switched on. Many short switch-on phases are visible neither to the sensor nor in the cloud. If the sensor signal is also used to determine the machine's operating hours, this results in a further disadvantage. This function is subject to significant inaccuracies and therefore cannot be used at all in individual cases.

[0063] Although a very high sampling rate could reliably detect the switched-on state even of short-cycle machines, this would not be sensible from an energy perspective and would not be a useful approach, particularly for battery-operated sensors, due to the shortened battery life caused by more frequent measurements and data transmission.

[0064] However, using the method according to the invention and the possibility of dynamic remote configuration of the sensor, this problem can be solved in a different way, as shown in Fig. 3. Initially, the sensor operates with normal sensor behavior (A). This behavior corresponds to that already explained above with reference to Fig. 2. Measurements are taken cyclically at a low measurement rate (measurement interval TA), and the measurement data are then always transferred directly to the cloud for evaluation.

[0065] However, as soon as this machine is identified on the cloud side as a short-cycle machine based on the previously collected sensor data, and clear detection thresholds between "switched on" and "switched off" have been determined for this machine, the sensor's behavior is changed. If the aforementioned preconditions are met and the machine now enters the state

[0066] "off", the cloud controls the sensor to mode (B) "MeasureCompareSleep" with command 5. At the same time, the on and off limit values ​​are transmitted from the cloud to the sensor. These limit values ​​were determined through prolonged observation and evaluation of the sensor data from this machine in the cloud. In the case of vibration data, these on / off limit values ​​can be, for example, rms values ​​or energy values ​​of the vibrations. The special feature of mode (B) of the sensor is that sensor values ​​are recorded in an energy-saving manner with a significantly shorter measurement interval TB. With vibration sensors, this is achieved, for example, by a shortened measurement time compared to mode (A). Furthermore, in mode (B), no data is sent to the cloud, so no energy is consumed. Characteristic values ​​can be derived from the sensor values, which are directly comparable with the limit values ​​available within the sensor.In the case of vibration data, these parameters can be, for example, rms values ​​or energy values ​​of the vibrations.

[0067] Based on the on / off threshold values ​​transmitted to the sensor, the sensor can locally evaluate whether the machine is still off (all observed parameters remain below the threshold values) or when the machine will be switched on (at least one of the parameters exceeds the corresponding threshold value). As soon as a threshold value is detected (reference numeral 6), the sensor automatically switches back to mode (A), i.e., it now records all sensor data for the full measurement duration and transmits it to the cloud. The device will now continue operating in mode (A) until it receives another command from the cloud to switch to mode (B).

[0068] The advantages of the inventive method are briefly summarized below.

[0069] When using battery-powered sensors or, more generally, HoT devices for machine monitoring, the quality of machine monitoring can be improved by applying the methods described here. Through targeted interaction between the cloud and the sensor / HoT device, the evidence of the physical values ​​recorded by the sensors on the machine can be significantly increased for various use cases. The special feature of this method is that it requires only a slight increase in energy consumption, thus only marginally impacting the battery life of the sensor / HoT device.

[0070] Specific advantages arise for the following use cases: a) A machine is monitored by a HoT device containing one or more sensors. The sensor / IoT device can be connected to a cloud. If a characteristic value determined by a sensor exceeds a specified limit, false alarms can be avoided by automatically initiating repeat measurements. Alarm messages are issued only after immediate verification by one or more repeat measurements, rather than immediately. b) A machine that is typically switched on for short cycles is monitored by a HoT device containing one or more sensors. The HoT device should be connected to a cloud. The monitoring of such a machine can be significantly improved in an energy-efficient manner. Furthermore, a desired operating time measurement can be carried out much more accurately based on the recorded sensor data.

Claims

Patent claims Method for monitoring at least one rotating work machine, in particular a centrifugal pump, comprising at least one sensor for detecting at least one measurement parameter relating to the operation of the work machine and a central evaluation unit which is communicatively connected to the at least one sensor, with the method steps: a. Transmitting at least one measured value and / or a measured value pre-processed on the sensor side by the sensor to the central evaluation unit, b. Evaluating the at least one measured value and / or the pre-processed measured value by the evaluation unit and generating at least one command for the dynamic remote configuration of the sensor behavior of the at least one sensor on the basis of the evaluation result, c. Transmitting the command from the evaluation unit to the at least one sensor.Method according to claim 1, characterized in that a repeat measurement is triggered by the sensor by means of the command and / or the number of repeat measurements to be performed and / or a time interval between repeat measurements to be performed is remotely configured. Method according to one of the preceding claims, characterized in that a threshold value for sensor-internal threshold monitoring is configured by means of the command. Method according to claim 3, characterized in that when the configurable threshold value is exceeded, the sensor enters an alarm state and / or generates and outputs an alarm message and / or carries out at least one repeat measurement and / or carries out data communication for transmitting the measurement data to the central evaluation unit. Method according to one of the preceding claims, characterized in that the at least one sensor comprises two or more, preferably different, measuring sensors and one or more measuring sensors can be deactivated or activated by means of the command. Method according to one of the preceding claims, characterized in that the sensor is put into a sleep or low-power mode by means of the command and / or the duration of a sleep or low-power phase is configured by means of the command.Method according to one of the preceding claims, characterized in that the process of measured value acquisition is configured by means of the command, e.g. a sampling rate and / or the measurement duration and / or the measurement data preprocessing and / or the data size of the measurement or raw data to be transmitted. Method according to one of the preceding claims, characterized in that the sensor detects mechanical vibrations and / or temperature values ​​in the area of ​​the work machine. Method according to one of the preceding claims, characterized in that, in the case of vibration data being detected by the sensor, a selection of the vibration axes and / or the configuration of the cutoff frequency is configured by means of the command.

10. Method according to one of the preceding claims, characterized in that the at least one sensor is a battery-operated sensor. 11 . Method according to at least one of the preceding claims, characterized in that the sensor goes into a first sleep mode after sending the one or more measured values ​​to the central evaluation unit and after ending the first sleep mode receives at least one command from the evaluation unit and / or carries out an internal sensor evaluation of the measured data and, depending on the internal sensor evaluations and / or the evaluation by the evaluation unit, carries out at least one repeat measurement to verify the previous measured data, wherein the sensor goes into a second sleep mode in the event that no repeat measurement is to be carried out.

12. Method according to one of the preceding claims, characterized in that the sensor, in a first mode of operation, records measured values ​​with a first measuring interval and transmits the measured values ​​to the central evaluation unit after each measurement, wherein the evaluation unit, after evaluating a series of received measured values, causes the sensor to operate in a second mode of operation.

13. Method according to claim 12, characterized in that by evaluating the series of measurements at least one detection threshold is determined and transmitted to the sensor, whereby the detection threshold can be used to differentiate between different machine states.

14. Method according to claim 12 or 13, characterized in that the sensor, according to a second mode of operation, records measured values ​​with a second measuring interval, wherein the second measuring interval is shorter than the first measuring interval, and during the second mode of operation no data or at least less data is transmitted to the central evaluation unit than in the first mode of operation.

15. Method according to one of claims 13 or 14, characterized in that the sensor changes to the first mode of operation if the current measured value or several consecutive measured values ​​exceed the detection threshold. System comprising at least one central evaluation unit, in particular a cloud-based evaluation unit, and at least one sensor, wherein the evaluation unit and sensor are configured to carry out the method according to one of the preceding claims 1 to 15. Sensor for a system according to claim 16, configured for dynamic remote configuration according to the method according to one of claims 1 to 15. Central evaluation unit for a system according to claim 16, configured for dynamic remote configuration of a sensor according to claim 17 according to the method according to one of claims 1 to 15.

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