Sensor arrangement for structural monitoring of a housing structure

Abstract

In a sensor arrangement for structural monitoring of a housing structure for receiving fluid or solid media with an outer shell, it is essential to the invention that the sensor arrangement has a central control unit, that the central control unit is designed to generate and receive structure-borne sound signal patterns, that the sensor arrangement has at least one transmitter unit, that the transmitter unit is spatially separated from the central control unit, that the at least one transmitter unit is designed to generate and receive structure-borne sound signal patterns, and that the central control unit has at least one evaluation device for evaluating the structure-borne sound signal patterns emitted by the transmitter units. Furthermore, the invention relates to a method for structural monitoring of a housing structure for receiving fluid or solid media.

Description

[0001] The invention relates to a sensor arrangement for structural monitoring of a housing structure for receiving fluids or solid media with an outer shell. The invention further relates to a method for structural monitoring of a housing structure for receiving fluids or solid media with an outer shell. A housing structure with an outer shell can, for example, be a tank for a vehicle. In particular, it can be a hydrogen tank having an outer shell made of a fiber-reinforced plastic, for example, glass fiber-reinforced plastic or carbon fiber-reinforced plastic. An inner gas-impermeable shell, for example made of PTFE, can also be arranged within the outer shell for the direct reception of a fluid medium.Such materials are durable over long periods and suitable for continuous operation in vehicles; however, material fatigue during cyclic operation or accidental impacts can lead to damage to the housing structure. Damage to the housing structure can, for example in the case of hydrogen tanks, result in the leakage of hydrogen, posing a significant safety hazard.

[0002] Hydrogen leak sensors are one example of a device used to detect hydrogen leaks. These sensors can measure the amount of hydrogen in the ambient air. A disadvantage of this method is that a warning can only be issued once a hydrogen leak has actually occurred.

[0003] The invention is based on the objective of proposing a sensor system and a method that makes it possible to detect weaknesses and possible damage in the housing structure before the absorbed medium leaks out.

[0004] This problem is solved by a sensor arrangement having the features of claim 1, by a method having the features of claim 8 and by a housing structure having the features of claim 12.

[0005] Further training and advantageous configurations are specified in the subclaims.

[0006] In a sensor arrangement for structural monitoring of a housing structure for receiving fluid or solid media with an outer shell, it is essential to the invention that the sensor arrangement has a central control unit, that the central control unit is designed to generate and receive structure-borne sound signal patterns, that the sensor arrangement has at least one transmitter unit, that the transmitter unit is spatially separated from the central control unit, that the at least one transmitter unit is designed to generate and receive structure-borne sound signal patterns, and that the central control unit has at least one evaluation device for evaluating the structure-borne sound signal patterns emitted by the transmitter units.

[0007] The sensor arrangement includes a central control unit designed to transmit and receive structure-borne sound signal patterns. For this purpose, the central control unit can, for example, include a structure-borne sound sensor that detects vibrations propagating along the housing structure. The structure-borne sound sensor can also actively generate vibrations that propagate along the housing structure. For this purpose, piezoelectric elements or similar devices can be used as structure-borne sound sensors. In addition to the central control unit, the sensor arrangement includes at least one, preferably several, transmitter units. These transmitter units are spatially separated from the central control unit; in particular, the central control unit and the transmitter units are each separate, individual components.The transmitter units are designed to generate and receive structure-borne sound signal patterns, and for this purpose they may include a structure-borne sound sensor, for example, in the form of a piezoelectric element. The central control unit and the transmitter units can be arranged at different positions within the housing structure. In particular, the central control unit can be located outside the housing structure, while the transmitter units can be located on the inside of the housing structure, i.e., facing the receiving volume of the housing structure. Structure-borne sound signal patterns emitted by the transmitter units can, for example, be detected and evaluated by the central control unit. For evaluation, the central control unit includes an evaluation device, for example, in the form of a processing unit, a microprocessor, or similar.The structure-borne sound signal patterns can be examined for characteristic properties, such as characteristic frequencies, characteristic signal waveforms, or similar features, which may indicate structural changes in the housing. Changes in the structure-borne sound signal patterns emitted by the transmitter units can also be investigated along the transmission path to the central control unit, or vice versa. Characteristic signal patterns indicating changes in the housing structure can, for example, be stored in a memory device for comparison purposes.

[0008] In a further development of the invention, the central control unit is configured to control the at least one transmitter unit by means of structure-borne sound signal patterns. The central control unit has at least one structure-borne sound sensor, which can also generate structure-borne sound signal patterns. For example, the structure-borne sound sensor can be a piezoelectric element. The structure-borne sound signal patterns generated by the central control unit propagate along the housing structure in the form of vibrations and can be detected by the transmitter units. Thus, the structure-borne sound signal patterns can be used for data transmission by encoding control commands, for example digitally or analogously, in the signal patterns.This makes it possible to control the transmitter units without having to establish extra data lines or a radio connection and without having to provide extra communication devices in the central control unit or the transmitter units.

[0009] In a further development of the invention, the sensor arrangement comprises several transmitter units. By using multiple transmitter units, which can be evenly distributed across the housing structure, monitoring of the entire housing structure is possible even in spatially extensive housing structures. For example, structure-borne sound signal patterns can be transmitted from one transmitter unit to the next, which then forwards the structure-borne sound signal pattern to the central control unit.

[0010] In a further development of the invention, at least one transmitter unit is designed for arrangement inside the housing structure. At least one, preferably several, transmitter units are mounted inside, for example on the side of the outer wall of the housing structure facing the receiving volume. By arranging the transmitter units inside the housing structure, external and internal changes to the housing structure can be detected and transmitted to the central control unit.

[0011] In one embodiment of the invention, the central control unit is designed for arrangement on the outside of the housing structure. By arranging the central control unit on the outside, simple data transfer from the central control unit to a system for further processing, for example, to an on-board computer of a vehicle, is possible.

[0012] In one embodiment of the invention, at least one transmitter unit comprises at least one structure-borne sound sensor, at least one processing unit, and at least one power supply. Each transmitter unit has a structure-borne sound sensor, in particular in the form of a piezoelectric element, which can also generate and transmit structure-borne sound signal patterns. For processing the received structure-borne sound signal patterns, the transmitter units have processing units, such as microcontrollers or other computing units. This allows control commands, which are transmitted from the central control unit to the transmitter units in the form of structure-borne sound signal patterns, to be processed and implemented accordingly. For example, the transmitter units can be instructed by control signals to transmit specific structure-borne sound signal patterns.Batteries, induction devices or similar may be provided for power supply.

[0013] In a further development of the invention, at least one power supply is an energy harvesting device. The propagating vibrations can generate voltages, and thus energy, by means of piezoelectric elements, which can be used to power the respective transmitter unit. Therefore, the transmitter units are completely self-sufficient, without the need for power supply lines or similar infrastructure.

[0014] A further aspect of the invention relates to a method for structural monitoring of a housing structure for containing fluid or solid media, wherein the sensor arrangement comprises at least one central control unit and at least one transmitter unit, the central control unit and the at least one transmitter unit being configured for generating and receiving structure-borne sound signal patterns, the transmitter unit emitting at least one structure-borne sound signal pattern, the central control unit receiving and evaluating the structure-borne sound signal pattern emitted by the transmitter unit, and the received structure-borne sound signal pattern being used to infer the condition of the housing structure. The method for structural monitoring of a housing structure is intended, in particular, to detect structural changes that could lead to a weakening of the housing structure at an early stage.In particular, a sensor arrangement according to the invention with a central control unit and several transmitter units can be used. The central control unit and the transmitter units are designed to generate and receive structure-borne sound signal patterns. Structure-borne sound signal patterns that arise during the operation of a vehicle or similar and propagate on the housing structure, especially the tank to be monitored, can be detected. Structure-borne sound signal patterns actively generated by the central control unit and the transmitter units can also be monitored and evaluated. Structure-borne sound signal patterns are generated by means of at least one transmitter unit, preferably by means of several transmitter units, for example by means of a piezoelectric element, so that the structure-borne sound signal pattern propagates on the housing structure.The central control unit receives the structure-borne sound signal pattern emitted by the transmitter unit and evaluates it using an evaluation unit. The presence of characteristic signal patterns, frequencies, waveforms, or similar characteristics allows conclusions to be drawn about the condition of the housing structure. Characteristic signal patterns, known to indicate damage to the housing structure, can be stored in a memory unit for comparison purposes. Changes in the structure-borne sound signal patterns, particularly their temporal evolution, can also be detected, with such changes indicating alterations to the housing structure. The generated structure-borne sound signal patterns can be filtered out from the vibrations that occur during operation, which constitute a kind of background noise, using algorithms.

[0015] Furthermore, it can be provided that a specific structure-borne sound signal pattern is emitted by a transmitter unit and received by the central control unit, or vice versa. By comparing the known emitted structure-borne sound signal pattern with the structure-borne sound signal pattern received by the central control unit, conclusions can be drawn about the condition of the housing structure. For example, the structure-borne sound signal pattern on the transmission path between the transmitter unit and the central control unit can change due to damage to the housing structure, making this damage detectable by the change. Thus, early detection of damage to the housing structure is possible before leaks of the contained fluid medium occur.

[0016] In a further development of the method, control commands in the form of structure-borne sound signal patterns are generated by the central control unit and sent to the transmitter units. Digitally or analogously encoded control commands can be sent from the central control unit to the transmitter units in the form of structure-borne sound signal patterns, for example, via wavelets, standing waves, chirps, or similar methods. This allows the transmitter units to be controlled, for example, to generate specific structure-borne sound signal patterns. Because the signal transmission between the central control unit and the transmitter units is via structure-borne sound, no additional data lines or similar infrastructure are required, thus enabling a cost-effective arrangement of the sensor array within the housing structure.

[0017] In a further development of the method, the condition of the housing structure is inferred from a deviation between a structure-borne sound signal pattern emitted by the transmitter unit and the structure-borne sound signal pattern received by the central control unit. The structure-borne sound signal emitted by the transmitter unit is known; in particular, the emission of this structure-borne sound signal pattern can be initiated by the central control unit via a control command. By comparing the expected signal pattern with the received signal pattern, a change in the housing structure or its condition can be inferred.

[0018] In one embodiment of the method, the sensor arrangement comprises multiple transmitter units. The housing structure is monitored by means of the structure-borne sound signal patterns transmitted back and forth between the transmitter units and the central control unit. Spatially extensive monitoring of the housing structure is enabled by a multitude of transmitter units, which can be arranged within the housing structure and between which structure-borne sound signal patterns are transmitted and received. Thus, impending damage can be detected in all areas of the housing structure.

[0019] The invention further relates to a housing structure for receiving fluid or solid media with an outer shell, wherein the housing structure comprises a sensor arrangement according to the invention, a central control unit is arranged on the outside of the housing structure, and at least one transmitter unit is arranged inside the housing structure. A housing structure with an outer shell can, for example, be a tank for a vehicle. In particular, the housing structure can have an outer shell made of a fiber-reinforced plastic, for example, glass fiber-reinforced plastic or carbon fiber-reinforced plastic. An inner gas-impermeable shell, for example made of PTFE, for the direct reception of a fluid medium can also be arranged in the outer shell. The central control unit and the transmitter units can be arranged at different positions within the housing structure.In particular, the central control unit can be located outside the housing structure, while the transmitter units can be located on the inside of the housing structure, i.e., facing the housing structure's receiving volume. By using multiple transmitter units, which can be evenly distributed throughout the housing structure, monitoring of the entire housing structure is possible even in spatially extensive housing structures.

[0020] The invention will now be explained in more detail with reference to an embodiment illustrated in the drawing. Specifically, the drawing shows... Fig. 1 a housing structure with a sensor arrangement.

[0021] In Fig.Figure 1 shows a housing structure 1 with a sensor arrangement consisting of a central control unit 2 and transmitter units 3. The housing structure 1 can be a hydrogen tank with a hydrogen valve 4. The transmitter units 3 are arranged on the inside of the outer shell 5 of the housing structure 1. The central control unit 2 is arranged outside the outer shell 5.

Claims

[1] Sensor arrangement for structural monitoring of a housing structure (1) for receiving fluid or solid media with an outer shell (5), characterized by , that the sensor arrangement has a central control unit (2), that the central control unit (2) is designed to generate and receive structure-borne sound signal patterns, that the sensor arrangement has at least one transmitter unit (3), that the transmitter unit (3) is spatially separated from the central control unit (2), that the at least one transmitter unit (3) is designed to generate and receive structure-borne sound signal patterns, and that the central control unit (2) has at least one evaluation device for evaluating the structure-borne sound signal patterns emitted by the transmitter units. [2] Sensor arrangement according to claim 1, characterized bythat the central control unit (2) is designed to control the at least one transmitter unit (3) by means of structure-borne sound signal patterns. [3] Sensor arrangement according to one of claims 1 or 2, characterized by that the sensor arrangement has several transmitter units (3). [4] Sensor arrangement according to one of claims 1 to 3, characterized by that at least one transmitter unit (3) is designed to be arranged inside the housing structure (1). [5] Sensor arrangement according to one of claims 1 to 4, characterized by that the central control unit (2) is designed to be arranged on the outside of the housing structure (1). [6] Sensor arrangement according to one of claims 1 to 5, characterized by that the transmitter units (3) have at least one structure-borne sound sensor and / or at least one power supply and / or at least one processing device. [7] Sensor arrangement according to one of claims 1 to 6, characterized by that the power supply is an energy harvesting facility. [8] Method for structural monitoring of a housing structure (1) for receiving fluid or solid media, wherein the sensor arrangement comprises at least one central control unit (2) and at least one transmitter unit (3), wherein the central control unit (2) and the at least one transmitter unit (3) are designed to generate and receive structure-borne sound signal patterns, wherein at least one structure-borne sound signal pattern is emitted by means of the transmitter unit (3), wherein the structure-borne sound signal pattern emitted by the transmitter unit (3) is received and evaluated by means of the central control unit (2), and wherein the condition of the housing structure (1) is inferred from the received structure-borne sound signal pattern. [9] Method according to claim 8, characterized bythat control commands in the form of structure-borne sound signal patterns are generated by the central control unit (2) and sent to the transmitter units (3). [10] Method according to one of claims 8 or 9, characterized by that the condition of the housing structure (1) is determined from a deviation between a structure-borne sound signal pattern emitted by the transmitter unit (3) and the structure-borne sound signal pattern received by the central control unit (2). [11] Method according to one of claims 8 to 10, characterized by that the sensor arrangement has a plurality of transmitter units (3) and that the housing structure (1) is monitored by structure-borne sound signal patterns sent back and forth between the transmitter units (3) and the central control unit (2). [12] Housing structure (1) for receiving fluid or solid media with an outer shell, wherein the housing structure (1) has a sensor arrangement according to the invention, wherein a central control unit (2) is arranged on the outside of the housing structure (1) and wherein at least one transmitter unit (3) is arranged in the interior of the housing structure (1).

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