Sensor unit

Abstract

Sensor unit (1) for carrying out capacitance measurements with a capacitor arrangement with two electrodes (2) separated by a dielectric layer (3) and with an evaluation unit (4) connected to the electrodes (2), in which an output signal is generated depending on measured values ​​generated with the electrodes (2), characterized in that each electrode (2) is formed by a textile surface element (12) with a surface arrangement of electrically conductive threads (13).

Description

[0001] The invention relates to a sensor unit.

[0002] Such sensor units are generally used to detect external influencing variables, whereby the sensor units are generally used in indoor and outdoor areas.

[0003] The sensor unit to which the invention relates comprises a capacitor arrangement configured to perform capacitance measurements. In a known manner, the capacitor arrangement comprises two electrodes separated by a dielectric layer. An evaluation unit generates output signals based on the capacitance measurements performed, which are then output to an external unit.

[0004] The invention is based on the object of providing a sensor unit of the type mentioned above which can be used flexibly and has a high level of functionality.

[0005] To achieve this object, the features of claim 1 are provided. Advantageous embodiments and expedient developments of the invention are described in the dependent claims.

[0006] The invention relates to a sensor unit for performing capacitance measurements using a capacitor arrangement with two electrodes separated by a dielectric layer and an evaluation unit connected to the electrodes, in which an output signal is generated depending on the measured values generated by the electrodes. Each electrode is formed by a textile surface element with a planar arrangement of electrically conductive threads.

[0007] By designing the electrodes of the capacitor arrangement in the form of textile surface elements with electrically conductive threads arranged on them, a compact, robust design of the sensor unit is achieved, which enables flexible installation in a wide variety of application environments.

[0008] Advantageously, the capacitor arrangement forms a pressure sensor.

[0009] The capacitor array forms a flexible, elastically deformable unit. When pressure is applied, the capacitor array deforms in the area of the dielectric, leading to a change in capacitance.

[0010] With the sensor unit according to the invention, a qualitative and / or quantitative measure of an acting pressure or an acting weight load can be determined, ie with the sensor unit an exact determination of acting pressure or weight forces is obtained.

[0011] Advantageously, the output signal is a measure of an applied pressure or weight load.

[0012] Alternatively or additionally, the output signal is a parameter generated depending on a registered pressure or weight load.

[0013] The variability of the output signals ensures high functionality of the sensor unit.

[0014] Advantageously, the evaluation unit is assigned an interface unit via which the output signal is output.

[0015] The output signal can be sent to an external unit via the interface unit.

[0016] A wired or contactless interface unit can be present.

[0017] A wireless interface, for example, can be provided as a contactless interface. This makes it possible to transmit the output signal even to distant external units.

[0018] According to an advantageous embodiment of the sensor unit, the electrically conductive threads consist of a metallized polyamide yarn or metallized polyamide fibers.

[0019] In particular, the electrically conductive threads are made of silver.

[0020] Furthermore, each textile surface element advantageously has a textile layer consisting of an electrically insulating material, to which the electrically conductive threads are applied.

[0021] The textile layer is a woven, knitted, braided or nonwoven fabric.

[0022] In principle, the electrically conductive threads can already be incorporated into the textile layer during its manufacturing process, particularly by machine.

[0023] It is particularly advantageous to have the electrically conductive threads embroidered onto the textile layer.

[0024] The embroidery can be carried out flexibly on the pre-produced textile layer, whereby different patterns and arrangements of conductive structures can be flexibly generated by embroidering the electrically conductive threads.

[0025] Advantageously, the electrically conductive threads cover the textile layer completely.

[0026] On the one hand, this means that the electrically conductive threads extend over the entire surface of the textile layer. On the other hand, the electrically conductive threads form an essentially closed conductive layer.

[0027] It is advantageous, but not mandatory, for the two electrodes to be identical.

[0028] According to a particularly advantageous design, a lower layer of electrically conductive threads is applied to the textile layer. A top layer of electrically conductive threads is applied to the lower layer.

[0029] This creates a particularly seamless conductive layer.

[0030] Advantageously, the underlayer is formed by intersecting electrically conductive threads.

[0031] In particular, the electrically conductive threads of the underlayer form a checkered pattern.

[0032] This creates a stable framework for the top layer, which advantageously forms a full-surface layer.

[0033] The lower layer and the upper layer are advantageously formed from the same electrically conductive threads.

[0034] Advantageously, the dielectric layer of the capacitor arrangement of the sensor unit is designed in the form of a foil which, like the electrodes, is bendable and elastically deformable.

[0035] Advantageously, the dielectric layer is a plastic layer.

[0036] In particular, the dielectric layer is made of PU (polyurethane).

[0037] The dielectric layer is generally not electrically conductive and therefore acts as an insulator between the electrodes.

[0038] According to a structurally advantageous embodiment, a hot-melt adhesive film is present between the dielectric layer and each electrode.

[0039] The hot melt adhesive films ensure a stable connection between the electrodes and the dielectric layer.

[0040] Advantageously, each hot melt adhesive film is made of a TPU (thermoplastic polyurethane).

[0041] According to a further variant of the invention, the capacitor arrangement consists of a spacer fabric in which the electrically conductive threads forming the electrodes are connected via pole threads made of non-conductive material. The pole threads form the dielectric layer between the electrodes.

[0042] According to an advantageous embodiment, the capacitor arrangement is arranged below an application layer or between two application layers.

[0043] The or each application layer can be adapted to the respective application. Generally, the application layers are designed to transfer any pressure or weight forces acting on them to the capacitor array, so that the application layers do not impair the capacitance measurements.

[0044] Advantageously, a hot melt adhesive film is present between the or each application layer and the capacitor arrangement.

[0045] This ensures a stable connection between the application layers and the capacitor arrangement.

[0046] In a first advantageous application of the sensor unit, the or each application layer is a geotextile laid out on a mountain slope. The capacitor arrangement measures the snow load present on the geotextile.

[0047] An alarm signal is advantageously generated as an output signal when a critical snow load is exceeded.

[0048] Particularly when multiple such systems are installed on different mountain slopes, it is useful to assign a GPS sensor to the evaluation unit of each sensor unit. The respective location is then output as an output signal along with the alarm signal. The output signals from the sensor units are then sent, for example, to a valley station. If an alarm signal is registered by a sensor unit there, an avalanche blasting can be initiated from there. This creates an efficient avalanche warning system.

[0049] In another advantageous application of the sensor unit, these are used to determine quantities of liquids transported in pipes.

[0050] In this case, the output signal is used to control or regulate the flow of fluids through the pipes.

[0051] One or more sensor units are then placed beneath the pipes. The condenser arrays measure the weight of the fluid flowing through them, registering the amount of fluid present, allowing the fluid flow to be precisely controlled or regulated.

[0052] Further advantageous applications of the sensor units are characterized by the fact that they are used to monitor the load on a loading area.

[0053] According to a first embodiment, at least one sensor unit can be provided with an application layer or by direct integration into the loading area of a truck. The correct loading of the loading area can be specified by target values for the measurement signals of the capacitor arrangement of the or each sensor unit. In the event of deviations from the target values, the or each sensor unit generates an alarm signal, thus ensuring effective theft protection. This also makes it possible to minimize empty truck runs, since sensor units can determine which zones of the loading area are occupied and which are not.

[0054] According to a further embodiment, the permissible total weight of a transporter can be controlled in this way.

[0055] Furthermore, an application of the sensor unit with such functionality can be configured such that it is arranged in a pallet. The output signal is implemented with anti-theft protection.

[0056] Another advantageous application of the sensor unit is its installation in the floor of a room. Person detection is achieved based on the output signal.

[0057] Of course, multiple sensor units can also be distributed. The sensor units can be integrated into the floor. Alternatively, an application layer with the sensor unit underneath can be applied to the floor.

[0058] This application is particularly useful in nursing homes and retirement homes. If, for example, a person falls out of bed, the sensor unit registers this and generates an alarm, allowing a caregiver to rush to help.

[0059] Another advantageous application for the sensor unit involves installing it in the floor of a parking space. The output signal indicates whether the parking space is occupied or unoccupied.

[0060] For applications in a parking garage or outdoor parking spaces, it is advantageous to equip all parking spaces with sensor units. Each sensor unit then sends its output signal with the respective location information, particularly the parking space number, to a control center, which can then indicate which parking spaces are free and which are occupied based on the sensor unit's output signals.

[0061] According to another advantageous application of the sensor unit, it is installed in the base of a shelf. The output signal is used to monitor the inventory on the shelf.

[0062] For known goods arranged on the shelf, the number of goods on the shelf can be determined based on the weight determination with the sensor unit.

[0063] In a shelving system with multiple shelves, such as those found in retail stores, it's advantageous to have a sensor unit on each shelf. Each sensor unit then sends its output signal with location information, such as the respective shelf number, to a control center where inventory is centrally monitored.

[0064] In a largely corresponding application of the sensor unit, it is located in a storage area of a logistics center. The output signal indicates the number of parts stored in the storage area.

[0065] In another advantageous application of the sensor unit, it is installed in a storage area of a construction site. The output signal provides anti-theft protection.

[0066] The sensor unit detects changes in inventory on the storage area by changing the measurement signals of the capacitor arrangements and sends them to a control center.

[0067] The invention is explained below with reference to the drawings. They show: Fig. 1: Schematic representations of an embodiment of the sensor unit according to the invention. Fig. 2: Textile layer for an electrode with a conductive underlayer. Fig. 3: Textile layer for an electrode with a conductive top layer.

[0068] Fig. 1 shows, highly schematically and not to scale, an embodiment of the sensor unit 1 according to the invention.

[0069] The sensor unit 1 is designed to perform capacitance measurements and, for this purpose, comprises a capacitor arrangement. The capacitor arrangement comprises two electrodes 2, between which a dielectric layer 3 is arranged. In this case, the electrodes 2 are identically designed.

[0070] According to the invention, the sensor unit 1 forms a pressure sensor. The capacitor arrangement forms a flexible, elastically deformable unit. When a pressure or weight force acts on the capacitor arrangement, it deforms, thereby changing the capacitance of the capacitor arrangement.

[0071] The sensor unit 1 has an evaluation unit 4, which in the present case has a sensor detection means 5 and a computer unit 6. The sensor detection means 5 is formed in the present case by an LC meter, and the computer unit 6 is formed by a microprocessor, microcontroller, or the like.

[0072] The electrodes 2 are connected to the LC meter via electrical lines 7, which in the simplest case are formed by wires.

[0073] The LC meter determines the current capacitance of the capacitor array. The measured values from the LC meter are evaluated in evaluation unit 4 to generate an output signal.

[0074] The output signal is transmitted to an external unit via an interface unit 8 of the evaluation unit 4. In principle, a wired interface unit 8 can be provided. In the present case, a contactless interface unit 8 is provided, for example, a radio interface.

[0075] The evaluation unit 4 optionally has a position sensor 9 with which the position of the sensor unit 1 is determined. In particular, the position sensor 9 can be a GPS sensor.

[0076] The capacitance measurements performed provide a measure of the pressure or weight forces acting on the capacitor arrangement. The output signal can therefore be an analog signal that is a measure of the pressure and weight forces acting.

[0077] This allows general loads on surfaces of application-specific objects to be determined and output.

[0078] With additional application information, object inspection, object counting, completeness checks and the like can also be carried out based on the measured values of the capacitor arrangement, whereby corresponding output signals are then generated.

[0079] In general, the measured values of the capacitor arrangement can be used to determine whether a pressure or weight load exceeds or falls below a critical value, whereby an alarm signal or an error message is generated as an output signal depending on this.

[0080] The dielectric layer 3 of the capacitor arrangement of the sensor unit 1 is advantageously a thermosetting plastic based on polyurethane.

[0081] How Fig. 1 shows, the electrodes 2 are each connected to the dielectric layer 3 by a hot melt adhesive film 10, which is preferably each formed from a TPU (thermoplastic polyurethane).

[0082] How Fig. As further shown in Figure 1, the capacitor arrangement is optionally located between two application layers 11. The application layers 11 can be formed from films or textile surfaces that form additional elements of the sensor unit 1. In general, only one application layer 11 can be provided, under which the capacitor arrangement is arranged. Generally, each application layer 11 is designed such that it transmits pressure or weight forces to the capacitor arrangement. Instead of separate application layers 11, the capacitor arrangement can also be incorporated into application-specific units. Hot-melt adhesive films 10 are also provided between the application layers 11 and the capacitor arrangement to connect these units.

[0083] According to the invention, each electrode 2 consists of a textile surface element 12 with electrically conductive threads 13 incorporated therein, as in Fig. 1 shown schematically.

[0084] The electrically conductive threads 13 consist of a metallized polyamide yarn or a metallized polyamide fiber, in particular of silver, the textile surface elements 12 otherwise consist of electrically insulating yarns.

[0085] Advantageously, each textile surface element 12 has a textile layer 14 consisting of an electrically insulating material, to which the electrically conductive threads 13 are applied.

[0086] The textile layer 14 is a woven fabric, knitted fabric, braided fabric or nonwoven fabric.

[0087] In the present case, the electrically conductive threads 13 are embroidered onto the textile layer 14.

[0088] The electrically conductive threads 13 expediently cover the textile layer 14 over its entire surface.

[0089] The Fig. 2 and Fig. 3 show an example of the structure of a textile surface element 12 with electrically conductive threads 13.

[0090] The left side of the arrangement according to the Fig. 2 and Fig. 3 shows the textile layer 14 without electrically conductive threads 13.

[0091] The right half of Fig. 2 shows the textile layer 14 with a sublayer of embroidered electrically conductive threads 13 forming a check pattern.

[0092] The right half of Fig. 3 shows the textile layer 14 with a top layer of electrically conductive threads 13 applied to the substructure by embroidery, which covers the textile layer 14 almost completely.

[0093] In the finished textile surface element 12, the lower layer and the upper layer cover the textile layer 14 over its entire surface.

[0094] Advantageously, the lower layer and the upper layer consist of the same electrically conductive threads 13. List of reference symbols 1 sensor unit 2 electrodes 3 dielectric layer 4 Evaluation unit 5 Sensor detection devices 6 Computer unit 7 Line 8 Interface unit 9 Position sensor 10 hot melt adhesive film 11 Application layer 12 textile surface element 13 electrically conductive thread 14 textile layers

Claims

[1] Sensor unit (1) for carrying out capacitance measurements with a capacitor arrangement with two electrodes (2) separated by a dielectric layer (3) and with an evaluation unit (4) connected to the electrodes (2), in which an output signal is generated depending on measured values generated by the electrodes (2), characterized by that each electrode (2) is formed by a textile surface element (12) with a planar arrangement of electrically conductive threads (13). [2] Sensor unit (1) according to claim 1, characterized by that the capacitor arrangement forms a pressure sensor. [3] Sensor unit (1) according to one of claims 1 or 2, characterized by that the capacitor arrangement forms a flexible, elastically deformable unit, wherein upon application of pressure a deformation of the capacitor arrangement occurs, which leads to a change in the capacitance of this capacitor arrangement. [4] Sensor unit (1) according to one of claims 2 or 3, characterized by that the output signal is a measure of an applied pressure or weight load. [5] Sensor arrangement according to one of claims 2 to 4, characterized by that the output signal is a parameter generated depending on a registered pressure or weight load. [6] Sensor arrangement according to one of claims 1 to 5, characterized by that the evaluation unit (4) is assigned an interface unit (8) via which the output signal is output. [7] Sensor arrangement according to claim 6, characterized by that a wired or contactless interface unit (8) is present. [8] Sensor unit (1) according to claims 1 to 7, characterized by that the electrically conductive threads (13) consist of a metallized polyamide yarn or a metallized polyamide fiber. [9] Sensor unit (1) according to claim 8, characterized bythat the electrically conductive threads (13) are made of silver. [10] Sensor unit (1) according to one of claims 1 to 9, characterized by that each textile surface element (12) has a textile layer (14) consisting of an electrically insulating material, to which the electrically conductive threads (13) are applied. [11] Sensor unit (1) according to claim 10, characterized by that the textile layer (14) is a woven, knitted, braided or nonwoven fabric. [12] Sensor unit (1) according to one of claims 10 or 11, characterized by that the electrically conductive threads (13) are embroidered onto the textile layer (14). [13] Sensor unit (1) according to one of claims 10 to 12, characterized by that the electrically conductive threads (13) completely cover the textile layer (14). [14] Sensor unit (1) according to one of claims 10 to 13, characterized bythat a lower layer of electrically conductive threads (13) is applied to the textile layer (14), wherein an upper layer of electrically conductive threads (13) is applied to the lower layer. [15] Sensor unit (1) according to claim 14, characterized by that the underlayer is formed by intersecting electrically conductive threads (13). [16] Sensor unit (1) according to claim 15, characterized by that the electrically conductive threads (13) of the underlayer form a check pattern. [17] Sensor unit (1) according to claim 16, characterized by that the top layer forms a full-surface layer. [18] Sensor unit (1) according to one of claims 14 to 17, characterized by that the lower layer and the upper layer are formed by the same electrically conductive threads (13). [19] Sensor unit (1) according to one of claims 1 to 18, characterized by that the dielectric layer (3) is a plastic layer. [20] Sensor unit (1) according to claim 19, characterized by that the dielectric layer (3) consists of PU (polyurethane). [21] Sensor unit (1) according to one of claims 1 to 20, characterized by that the dielectric layer (3) is a thermosetting plastic. [22] Sensor unit (1) according to one of claims 1 to 21, characterized by that a hot-melt adhesive film (10) is present between the dielectric layer (3) and each electrode (2). [23] Sensor unit (1) according to claim 22, characterized by that each hot melt adhesive film (10) consists of a TPU (thermoplastic polyurethane). [24] Sensor unit (1) according to one of claims 1 to 9, characterized bythat the capacitor arrangement consists of a spacer fabric in which electrically conductive threads (13) forming the electrodes (2) are connected via pole threads made of non-conductive material, the pole threads forming the dielectric layer (3) between the electrodes (2). [25] Sensor unit (1) according to one of claims 1 to 24, characterized by that the capacitor arrangement is arranged below an application layer (11) or between two application layers (11). [26] Sensor unit (1) according to claim 25, characterized by that a hot-melt adhesive film (10) is present between the or each application layer (11) and the capacitor arrangement. [27] Sensor unit (1) according to one of claims 25 or 26, characterized by that the or each application layer (11) is a geotextile laid out on a mountain slope, wherein the capacitor arrangement measures a snow load present on the geotextile. [28] Sensor unit (1) according to claim 27, characterized by that when a critical snow load is exceeded, an alarm signal is generated as an output signal. [29] Sensor unit (1) according to one of claims 25 or 26, characterized by that this quantity of liquids transported in pipes can be determined. [30] Sensor unit (1) according to claim 29, characterized by that the output signal is used to control or regulate the flow of fluids through the pipes. [31] Sensor unit (1) according to one of claims 25 or 26, characterized by that it is used to monitor the load on a loading area. [32] Sensor unit (1) according to one of claims 25 or 26, characterized by that it is installed in the floor of a room and that the output signal is used to detect people. [33] Sensor unit (1) according to one of claims 25 or 26, characterized bythat it is laid in the floor of a parking space, with the output signal indicating the occupancy or non-occupancy of the parking space. [34] Sensor unit (1) according to one of claims 25 or 26, characterized by that it is arranged in a pallet and that the output signal provides anti-theft protection. [35] Sensor unit (1) according to one of claims 25 or 26, characterized by that it is arranged in the base of a shelf and that the output signal is used to check the stock of goods on the shelf. [36] Sensor unit (1) according to one of claims 25 or 26, characterized by that it is arranged in a storage area of a logistics center, whereby the output signal indicates the number of parts stored in the storage area. [37] Sensor unit (1) according to one of claims 25 or 26, characterized bythat it is arranged in a storage area of a construction site, whereby theft protection is realized based on the output signal.

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