Method and means for monitoring a conveyor device

Abstract

The invention relates to a computer-implemented method for monitoring a conveyor device (12), wherein the conveyor device (12) comprises a plurality of elements (20) and is designed such that the plurality of elements (20) are movable along a conveying direction (22) of the conveyor device (12), comprising the steps - receiving a first signal, the first signal representing sound generated during operation, and in particular during normal operation, of the conveying device (12), - receiving a second signal, the second signal representing a time of passage of an element (20) of the conveyor device (12) past a light barrier (18), - Assigning the received first signal to elements (20) of the conveyor device (12) taking into account the received second signal, and - Monitoring the conveyor device (12) by analyzing the associated first signal. Furthermore, the invention relates to a device (14) for data processing comprising means for carrying out the above method. Furthermore, the invention relates to a system (10) comprising a conveyor device (12), the above device (14) for data processing, at least one microphone (16) and at least one light barrier (18).

Description

Technical field

[0001] The invention relates to a computer-implemented method for monitoring a conveyor device.

[0002] Furthermore, the invention relates to a device for data processing comprising means for carrying out the above method, a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out the above method, and a computer-readable data carrier on which the above computer program product is stored.

[0003] Furthermore, the invention relates to a system comprising a conveying device and the above device for data processing. Background of the invention

[0004] Conveyor systems, and in particular sorters, as logistical sorting and distribution systems for transporting and / or sorting objects, especially piece goods, are well known in the art. As a result of e-commerce and online mail order offerings, the amount of piece goods to be transported and / or sorted has increased significantly. The reliability of the conveyor systems is therefore crucial, as technical problems always pose the risk of unplanned downtime of the conveyor system. This is associated with significant delays, capacity restrictions, and costs.

[0005] Accordingly, there is a need for means to monitor the conveyor system to alert the operator to potential problems at an early stage. There is a particular need for monitoring systems that can detect future and potentially serious errors very early on, allowing countermeasures to be initiated to prevent the conveyor system from coming to a standstill. Another disadvantage of existing monitoring systems is that they are only capable of detecting the presence of a potential malfunction, but do not allow the error to be attributed to individual components of the conveyor system. The subsequent troubleshooting is correspondingly complex. Description of the invention

[0006] Based on this situation, it is an object of the present invention to improve the monitoring of conveyor devices and, in particular, to enable an assignment of a potentially future occurring error to a specific component of the conveyor device.

[0007] The object of the invention is achieved by the features of the independent claims. Advantageous embodiments are specified in the subclaims.

[0008] Accordingly, the object is achieved by a computer-implemented method for monitoring a conveyor device, wherein the conveyor device comprises a plurality of elements and is designed such that the plurality of elements are movable along a conveying direction of the conveyor device, comprising the steps: - receiving a first signal, the first signal representing sound generated during operation, and in particular during normal operation, of the conveying device, - receiving a second signal, the second signal representing a time of passage of an element of the conveyor device past a light barrier, - Assigning the received first signal to elements of the conveyor device taking into account the received second signal, and - Monitoring the conveyor device by analyzing the associated first signal.

[0009] Furthermore, the object is achieved by a device for data processing comprising means for carrying out the above method.

[0010] Furthermore, the object is achieved by a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out the above method.

[0011] Furthermore, the problem is solved by a computer-readable data carrier on which the above computer program product is stored.

[0012] Furthermore, the object is achieved by a system comprising a conveyor device, the above data processing device, at least one microphone and at least one light barrier, wherein the conveyor device comprises a plurality of elements and is designed such that the plurality of elements are movable along a conveying direction of the conveyor device, wherein the microphone is designed to generate a first signal based on sound, wherein the light barrier comprises a light source and a light sensor and is designed to generate a second signal based on optical signals, and wherein the microphone and the light barrier are communicatively connected to the data processing device such that the first and second signals can be received by the data processing device.

[0013] One aspect of the invention is that by receiving the second signal, which represents the passage of an element of the conveyor device past the light barrier, the first signal representing the sound is assigned to individual elements of the conveyor device. In other words, the second signal fulfills the function of a timestamp for the passage of an element past the light barrier. In still other words, a temporal assignment preferably takes place between the second and the first signal. This makes it possible for the subsequent analysis of the first signal not only to determine the presence of an error or future potential error, but also to assign this error to a specific element of the conveyor device as the error source.Accordingly, targeted maintenance of the conveyor device and, in particular, early maintenance of the element of the conveyor device identified as the source of the error can be carried out.

[0014] In the first step of the computer-implemented method, the first signal is received. Preferably, the first signal represents a sound generated during operation, and in particular during regular operation, of the conveying device. In other words, the first signal preferably represents a time-continuous physical quantity generated by the operation of the conveying device, in particular the sound pressure. Preferably, the first signal is a digital signal, and more preferably a time-discrete digital signal, which is received in the first step by the data processing device for further evaluation. The digital signal may have been generated by conversion from an analog audio signal.

[0015] In the second step of the method, the second signal is received. The second signal preferably represents a time at which an element of the conveying device passes the light barrier. The second signal is preferably a time-discrete signal and, in particular, a digital signal. In other words, an optical signal generated by the movement of the elements along the conveying direction at the light barrier is preferably converted into a digital signal, which is then received by the data processing device for further evaluation in the second step.

[0016] After the first signal has been assigned to elements of the conveyor device by taking the second signal into account, the conveyor device is subsequently monitored by analyzing the assigned first signal. Particularly preferably, taking the second signal into account includes assigning the first and second signals to one another based on the time of the two signals.

[0017] According to a preferred development of the invention, monitoring the conveyor device includes identifying an irregular element of the conveyor device. An irregular element is preferably understood to be an element whose function deviates from the norm. An irregular element does not necessarily lead to a malfunction of the conveyor device. However, the presence of an irregular element generally increases the probability that such a malfunction of the conveyor device will occur in the future. The detection of irregular elements therefore enables proactive maintenance of the conveyor device, whereby the conveyor device can be maintained predictively.This enables cost savings compared to routine or time-based preventive maintenance strategies, since maintenance only needs to be carried out when justified by the presence of an irregular element.

[0018] According to a further development of the invention, it is particularly preferred that the monitoring of the conveyor device be carried out using machine learning and / or statistical methods. This makes it possible to reliably detect irregular elements in a manner specifically tailored to the conveyor device and its environment. The statistical methods preferably use dynamic and / or rolling statistical surveys for monitoring.

[0019] According to a preferred development of the invention, it is provided that the first received signal comprises amplitude values ​​at successive points in time. It is further preferably provided that the method comprises the step of determining frequencies contained in the first signal. In other words, the spectrum of the first signal is preferably determined; more preferably, the spectrum is determined in temporally successive signal sections of the first signal. In this way, it is possible to determine the proportion of the frequencies contained in the first signal over time. This makes it possible to detect irregular elements of the conveying device by analyzing the amplitude values ​​at the respective frequencies and / or in predefined frequency ranges. In particular, it has been found that irregular elements of the conveying device have higher amplitude values ​​in certain frequency ranges.

[0020] According to a preferred development of the invention, the step of assigning the received first signal to elements of the conveyor device, taking into account the received second signal, results in amplitude values ​​being obtained at multiple frequencies and multiple times for each element of the conveyor device. Thus, an element-specific analysis of the first signal preferably takes place.

[0021] According to a further preferred development of the invention, the step of assigning the received first signal to elements of the conveyor device, taking into account the received second signal, includes taking into account a conveying speed of the conveyor device, a length of the conveyor device along the conveying direction, and / or a number of elements of the conveyor device. In particular, the conveying speed, the length of a conveyor device, preferably configured as a circular route, and / or the number of elements can be used to precisely assign the first signal to the respective elements of the conveyor device.

[0022] According to a further preferred development of the invention, the method comprises the step of checking the received first signal taking into account the received second signal and discarding the received first signal in the event that the received first signal is not regular in the time axis. In other words, to rule out the possibility that poor quality of the first signal leads to an incorrect conclusion with regard to the detection of irregular elements, it is preferably provided that the first signal is checked with regard to its regularity in the time axis. Particularly preferably, this checking takes place taking into account comparison data by means of machine learning and / or statistical methods.With regard to machine learning, it is particularly preferred that an algorithm generates a model based on the comparison data to distinguish regular from irregular initial signals. Based on the previously recorded and then known errors, the algorithm is thus also able to identify error types and perform automated error classification.

[0023] With regard to monitoring, according to a further preferred development of the invention, it is provided that the monitoring of the conveying device comprises comparing an amplitude value in a frequency band with a limit value. Preferably, the limit value is a frequency band-dependent limit value. Further preferably, it is provided that the monitoring of the conveying device comprises comparing the amplitude values ​​in all frequency bands with the frequency band-dependent limit values. Particularly preferably, the limit value and / or the frequency band-dependent limit values ​​are determined taking into account comparison data using dynamic and / or rolling statistical surveys. Alternatively or additionally, it can be provided that the limit value and / or the frequency-dependent limit values ​​are determined by means of machine learning.

[0024] According to a further preferred development, it is preferably provided in this context that the limit value is an element-dependent limit value. In particular, if the conveying device has elements of different configurations, for example, elements with their own drive and / or elements with brushes, some of the elements are louder than others due to the configuration of the individual elements. Accordingly, it is advantageous for the limit value to be an element-dependent limit value, since this allows different elements to be considered differently during the evaluation and, for example, generally louder elements to be evaluated separately.

[0025] Furthermore, according to a preferred development of the invention, the method comprises the step of generating a warning and / or an alarm when the limit value is exceeded in a specific frequency band and / or when the limit value is exceeded in multiple frequency bands. This enables efficient maintenance of the conveyor device. Warnings are preferably generated for elements that have amplitude values ​​higher than the limit value, while alarms are triggered for elements whose amplitude values ​​approach the limit value for the frequency range several times within a predefined period of time.

[0026] According to a further preferred development of the invention, it is provided in this context that the monitoring of the conveyor device comprises comparing an amplitude value with a limit value over several revolutions of the conveyor device. This has the advantage that one-off effects, such as background noise with a high amplitude and / or interference noise caused by insufficiently packaged piece goods, do not directly lead to the generation of a warning and / or an alarm, since these do not persist over several revolutions of the conveyor device. Preferably, a warning and / or an alarm is therefore only generated if the limit value is exceeded during a predefined number of revolutions out of a plurality of revolutions. In other words, a warning and / or an alarm can only be generated if an increased amplitude persists over several revolutions of the conveyor device.Alternatively, monitoring the conveyor device can also involve calculating an amplitude average over several amplitude values, and comparing the amplitude average with the threshold value. The method is thus particularly suitable for enabling monitoring during normal operation of the conveyor device, as it is capable of distinguishing between initial signals representing the sound of defective elements and initial signals representing the sound of one-off effects—such as the transport of a particularly heavy piece of cargo on the conveyor device.In other words, the monitoring of the conveyor device is preferably carried out in such a way that associated first signals which are attributable to irregular elements of the conveyor device can be distinguished from associated first signals which are attributable to piece goods arranged irregularly on the conveyor device and / or which are attributable to piece goods which deviate from the norm.

[0027] Further technical features and advantages of the method for monitoring the conveyor device will become apparent to the person skilled in the art from the following description of the data processing device, the computer program product, the computer-readable data carrier and the system.

[0028] As already mentioned, the invention also relates to a data processing device comprising means for carrying out the method described above. The data processing device is particularly preferably server-based. The data processing device preferably comprises means for receiving the first and / or second signal. Further preferably, the data processing device comprises at least one memory for storing the first signal and / or the second signal and / or a programmable arithmetic unit.

[0029] Furthermore, the invention relates to the computer program product, comprising instructions that, when executed by a computer, cause the computer to perform the above-described method. Furthermore, the invention relates to the computer-readable data carrier on which the above-described computer program product is stored.

[0030] The person skilled in the art will understand the technical effects and advantages of the data processing device, the computer program product and / or the computer-readable data carrier through the above description of the computer-implemented method for monitoring the conveyor device and through the following description of the system comprising the conveyor device and the data processing device.

[0031] As already mentioned, the object of the invention is also achieved by the system comprising the conveying device, the above-described data processing device, at least one microphone and at least one light barrier, wherein the conveying device comprises a plurality of elements and is designed such that the plurality of elements are movable along a conveying direction of the conveying device, wherein the microphone is designed to generate a first signal based on sound, wherein the light barrier comprises a light source and a light sensor and is designed to generate a second signal based on optical signals, and wherein the microphone and the light barrier are communicatively connected to the data processing device such that the first and second signals can be received by the data processing device.

[0032] It is preferably provided that the microphone is designed to represent the sound pressure generated during operation of the conveying device in the form of the first signal, i.e., preferably in the form of a digital signal, and to communicatively forward it to the data processing device. It is further preferably provided that the light barrier is designed to represent the optical signal as the second, preferably digital, signal and to communicatively forward it to the data processing device. The first and / or second signal can be transmitted wirelessly or via a cable.

[0033] The conveying device is preferably designed for transporting and / or sorting objects, in particular piece goods. In this context, according to a preferred development of the invention, the conveying device is designed as a circular track and / or the plurality of elements are movable synchronously along the conveying direction and / or the elements are designed to move objects arranged on the elements perpendicular to the conveying direction.

[0034] The elements of the conveyor device can all be designed identically. Alternatively, it is possible for the elements of the conveyor device to be designed differently from one another. In other words, the conveyor device can comprise differently designed elements—for example, elements with their own drive and / or elements with brushes. Particularly preferably, at least some elements of the conveyor device comprise a conveyor belt and are designed to move objects arranged on the element perpendicular to the direction of the circular path.

[0035] According to a further preferred development of the invention, in this context, the conveyor device is designed as a cross-belt sorter and / or the element comprises a belt conveyor and / or a band conveyor. Accordingly, the object can be moved very easily perpendicular to the conveying direction of the conveyor device.

[0036] In principle, the microphone can be attached at different points on the conveyor device, for example on a straight section of the conveyor device. With regard to the arrangement of the microphone, according to a further preferred development of the invention, the microphone is arranged in relation to the conveyor device such that sound generated in a curve of the conveyor device is within the reception range of the microphone and / or that the microphone is arranged no more than 1 m away from a curve of the conveyor device and is particularly preferably arranged in the curve radius of the conveyor device. Since the elements of the conveyor device usually have main impellers and side impellers and, in particular in curves, the side impellers are in contact with other parts of the conveyor device, arranging the microphone close to the curve enables sound generated by the movement of the side impellers to be received.Accordingly, this arrangement increases the reliability of the method for monitoring the conveyor device.

[0037] In connection with the arrangement of the microphone, according to a further preferred embodiment of the invention, the microphone is mounted on a static component of the conveyor device and / or beneath an underside of the elements of the conveyor device. This enables particularly good reception of the sound of the conveyor device, and in particular the sound generated by the rotation of the main impellers and / or side impellers.

[0038] With respect to the light barrier, it is preferably provided that the light sensor of the light barrier generates the second signal based on an optical signal from the light source reflected by the elements of the conveyor device. In this way, the time at which an element of the conveyor device passes the light barrier can be determined precisely. Particularly preferably, a sensitivity threshold of the light sensor is exceeded due to reflection, which leads to the generation of the second signal.

[0039] In this context, according to a further preferred development of the invention, at least one element of the conveyor device is equipped with a reflector, and the light source of the light barrier is preferably arranged relative to the conveyor device such that a light beam from the light source strikes the reflector perpendicularly as the element passes through. The system is preferably designed such that only one of the multiple elements of the conveyor device is equipped with a reflector. Accordingly, the method preferably uses the time of passage of this one element to assign the received first signal to the elements of the conveyor device based on the conveyor speed, the length of the conveyor device and / or the number of elements. Alternatively, multiple elements of the conveyor device can also be equipped with a reflector. Short description of the drawings

[0040] The invention is explained in more detail below with reference to the accompanying drawings using a preferred embodiment.

[0041] The drawings show Fig. 1 a schematic representation of a system according to a preferred embodiment of the invention, and Fig. 2 a schematic representation of a section of the Fig. 1 shown system. Detailed description of the embodiment

[0042] Fig. 1 shows a schematic representation of a system 10 comprising a conveyor device 12, a data processing device 14, a microphone 16 and a light barrier 18, according to a preferred embodiment of the invention.

[0043] The conveyor device 12 is configured as a cross-belt sorter 12 and comprises a plurality of elements 20 that are movable in a circular path along a conveying direction 22. The microphone 16 is configured to generate a first signal based on sound. In this case, the first signal is a digital signal. The light barrier 18, which comprises a light source and a light sensor, is configured to generate a second signal based on optical signals. In this case, the second signal is also a digital signal. The microphone 16 and the light barrier 18 are arranged directly in front of a curve in the circular path of the conveyor device 12.

[0044] The microphone 16 and the light barrier 18, both in Fig. 1 are only shown schematically, are communicatively connected to the data processing device 14 such that the first and second signals can be received by the data processing device 14.

[0045] Fig. 2 shows a schematic representation of a section of the Fig. 1 shown system 10. In particular, in Fig. 2 that the microphone 16 is attached to a static component 24 of the conveyor device 12. In the present case, the microphone 16 is mounted below a bottom side of the elements 20 of the conveyor device 12 at a distance of approximately 50 cm from the elements 20.

[0046] The data processing device 14 is configured to carry out the computer-implemented method for monitoring the conveyor device 12 described below: In one step of the method, the first signal is received, wherein the first signal represents sound generated during the normal operation of the conveyor device 12. The fact that the conveyor device 12 is in normal operation in the present case is Fig. 1 can be seen from the fact that on some of the elements 20 piece goods 26 are arranged.

[0047] In a further step of the method, the second signal is received, wherein the second signal represents a time of passage of an element 20 of the conveyor device 12 past the light barrier 18.

[0048] In a step following the previous steps, the received first signal is assigned to the elements 20 of the conveyor device 12 taking into account the received second signal.

[0049] Subsequently, in a further step, the conveyor device 12 is monitored by analyzing the associated first signal.

[0050] In the present embodiment, exactly one element 20 of the conveyor device 12 has a reflector, so that the light barrier 18 detects the time at which this one element 20 passes the light barrier 18. Using this time, which acts as a time stamp, the received first signal can be assigned to the corresponding elements 20 of the conveyor device 12.

[0051] Accordingly, for each revolution of the conveyor device 12, a series of amplitude values ​​results for each element 20. In the present exemplary embodiment, a configurable number of historical comparison data is taken into account to monitor the conveyor device 12. The default value for the number of days of historical comparison data to be taken into account is 15 days; 7 days have proven sufficient. In the present exemplary embodiment, the data from the last 15 days are taken into account as historical comparison data. Since the received first signal is checked for its regularity in its time axis, taking into account the received second signal, and irregular signals are discarded, this typically leads to approximately 100,800 data series with amplitude values ​​for a conveyor device 12 comprising 1,400 elements, with approximately 60 evaluable revolutions of the conveyor device per working day.Each data series with amplitude values ​​contains approximately 43 individual amplitude values.

[0052] When monitoring the conveyor device 12, in the present embodiment, irregular elements 20 of the conveyor device 12 are identified. This is made possible because it has been determined that irregular elements 20 generate higher amplitudes in some frequency ranges than non-irregular elements 20. Therefore, if an element 20 has higher amplitudes for a certain frequency range than other elements 20 of the conveyor device 12, the probability that the element 20 is defective is high.

[0053] In this preferred embodiment, frequency band-dependent limit values ​​are determined using statistical methods, taking historical comparison data into account. When monitoring the conveyor device 12, each frequency range is then checked for each element 20. Warnings are generated for elements 20 exhibiting significantly elevated amplitude values; alarms are triggered for elements 20 with amplitude values ​​that regularly approach the limit value for a specific frequency range. Accordingly, the elements 20 identified as irregular can be specifically maintained.

[0054] The described embodiment is merely an example which can be modified and / or supplemented in many ways within the scope of the claims. List of reference symbols 10 systems 12 Conveyor device 14 Data processing device 16 microphones 18 light barrier 20 elements 22 Conveying direction 24 Static component 26 general cargo

Claims

[1] Computer-implemented method for monitoring a conveyor device (12), wherein the conveyor device (12) comprises a plurality of elements (20) and is designed such that the plurality of elements (20) are movable along a conveying direction (22) of the conveyor device (12), comprising the steps: - receiving a first signal, the first signal representing sound generated during operation, and in particular during control operation, of the conveying device (12), - receiving a second signal, the second signal representing a time of passage of an element (20) of the conveyor device (12) past a light barrier (18), - Assigning the received first signal to elements (20) of the conveyor device (12) taking into account the received second signal, and - Monitoring the conveyor device (12) by analyzing the associated first signal. [2] Method according to the preceding claim, wherein the monitoring of the conveyor device (12) comprises identifying an irregular element (20) of the conveyor device (12), and / or wherein the monitoring of the conveyor device (12) is carried out by means of machine learning and / or statistical methods. [3] Method according to one of the preceding claims, wherein the first received signal comprises amplitude values at successive times and / or wherein the method comprises the step of determining frequencies contained in the first signal. [4] Method according to one of the preceding claims, wherein the step of assigning the received first signal to elements (20) of the conveyor device (12) taking into account the received second signal comprises taking into account a conveying speed of the conveyor device (12), a length of the conveyor device (12) along the conveying direction (22) and / or a number of elements of the conveyor device. [5] A method according to any one of the preceding claims, wherein the method comprises the step of checking the received first signal taking into account the received second signal and discarding the received first signal in the event that the received first signal is not regular in the time axis. [6] Method according to one of the preceding claims, wherein monitoring the conveyor device (12) comprises comparing an amplitude value in a frequency band with a limit value and / or wherein the method comprises the step of generating a warning and / or an alarm when the limit value is exceeded in a specific frequency band and / or when the limit value is exceeded in several frequency bands. [7] Method according to one of the preceding claims, wherein the monitoring of the conveyor device (12) comprises comparing an amplitude value with a limit value over several revolutions of the conveyor device (12); and / or wherein the monitoring of the conveyor device (12) is carried out in such a way that associated first signals which are attributable to irregular elements (20) of the conveyor device (12) can be distinguished from associated first signals which are attributable to piece goods (26) arranged irregularly on the conveyor device and / or which are attributable to piece goods (26) deviating from the norm. [8] Device (14) for data processing comprising means for carrying out the method according to one of the preceding method claims. [9] Computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to one of the preceding method claims. [10] A computer-readable data carrier on which the computer program product according to the preceding claim is stored. [11] System (10) comprising a conveyor device (12), a device (14) for data processing designed according to claim 8, at least one microphone (16) and at least one light barrier (18), wherein the conveying device (12) comprises a plurality of elements (20) and is designed such that the plurality of elements (20) are movable along a conveying direction (22) of the conveying device (12), wherein the microphone (16) is designed to generate a first signal based on sound, wherein the light barrier (18) comprises a light source and a light sensor and is designed to generate a second signal based on optical signals, and wherein the microphone (16) and the light barrier (18) are communicatively connected to the data processing device (14) such that the first and second signals can be received by the data processing device (14). [12] System (10) according to the preceding system claim, wherein the conveying device (12) is designed as a circular course and / or wherein the plurality of elements (20) are movable synchronously along the conveying direction (22) and / or wherein the elements (20) are designed to move objects (26) arranged on the elements (20) perpendicular to the conveying direction (22). [13] System (10) according to one of the preceding system claims, wherein the microphone (16) is arranged relative to the conveyor device (12) such that sound generated in a curve of the conveyor device (12) is in the reception range of the microphone (16) and / or wherein the microphone (16) is arranged no more than 1 m away from a curve of the conveyor device (12). [14] System (10) according to one of the preceding system claims, wherein the microphone (16) is mounted on a static component (24) of the conveyor device (12) and / or below a bottom side of the elements (20) of the conveyor device (12). [15] System (10) according to one of the preceding system claims, wherein at least one element (20) of the conveying device (12) is equipped with a reflector, and wherein preferably the light source of the light barrier (18) is arranged relative to the conveying device (12) in such a way that a light beam of the light source strikes the reflector perpendicularly when passing through the element (20).

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