Sensor having a slotted force-conducting element

Abstract

The invention relates to a sensor plate (1) for measuring force distributions, having a sensor element (2) with at least one sensor cell (3) forming a discrete sensitive region, and at least one pressure-conducting element (4) which is connected to the sensor element (2) and positioned for force transmission to the at least one sensor cell (3), wherein the pressure-conducting element (4) has at least one pressure-conducting hump (5), wherein each sensor cell (3) is assigned a pressure-conducting hump (5) positioned thereon, such that an extensively applied load is conducted in a targeted manner and primarily via one or more sensor cells (9), wherein the pressure-conducting hump (5) has at least one recess (6).

Description

[0001] 202403264 1

[0002] Description

[0003] Sensor with slotted force conductor

[0004] The present invention relates to a sensor with a slotted force-guiding element for measuring force distributions using printed electronics as well as for measuring force distributions with force-guiding studs which are fixed on a separate element, not in a fixed position on the sensor.

[0005] It is known that only force distributions can be measured, not total forces, because in addition to the discrete sensor positions, force bypasses occur.

[0006] Even a slight misalignment between the force-guiding stud and the sensor during operation changes the sensor's characteristics or calibration curve (measured value vs. applied force). This results in significant inaccuracies in the measured force.

[0007] The measuring principle of flat printed resistive or capacitive sensors is based approximately on a measurement of the contact area or a distance between two conductive surfaces, which are kept apart, at least in some areas, by a dielectric.

[0008] When pressure is applied, the two conductive surfaces move closer together or come into contact with each other. The change in distance or contact area results in a measurable value in the form of electrical resistance or capacitance.

[0009] The measurable force range is defined on the one hand by a minimum pressure / or force required to cause a relevant change in the two 202403264 2

[0010] to determine quantities. In the case of a resistive measurement, it is the initial contact between the two conductors. On the other hand, the end of the measurable force range is reached when increasing the pressure no longer results in a relevant change in the distance or contact area.

[0011] The known measurement principles are designed for smaller measurement ranges. Special designs within the force measuring cell attempt to maximize the measurable force range. However, the maximum possible resolution is severely limited by the sensor's low profile and the physical material properties within it.

[0012] GB 2482192B

[0013] US 2020319044 A1

[0014] DE 10 2011 016 344 A1

[0015] One object of the present invention is the development of a compact sensor plate with discrete sensor positions and force application into these positions, resulting in a stable and robust sensor characteristic. Preferably, the force application is achieved without force shunting, in order to enable the measurement of absolute forces and to minimize potential errors in the measured force distribution. Preferably, the measurable force range is extended with the highest possible resolution.

[0016] The problem is solved according to the invention as follows.

[0017] A sensor plate consisting of:

[0018] A sensor element (preferably using pressure-sensitive resistive sensor elements, alternatively electroactive polymers or other capacitive or inductive sensors) with one or more discrete sensitive areas (sensor cells). 202403264 3

[0019] Force transmission to the sensor cells by means of one or more pressure-conducting elements, which are preferably materially bonded and positioned with the sensor element.

[0020] Pressure guide element with one or more pressure guide studs, each assigned to a sensor cell and positioned accordingly on it, so that a surface-acting load is directed specifically and mainly through one or more sensor cells.

[0021] Pressure guide tunnel slotted, preferably with a recess depth of min 25% of the maximum height of the tunnel.

[0022] Preferably with multiple slots, for example 3-6 times.

[0023] Slots preferably essentially perpendicular to the main direction of the pressure guide tunnel.

[0024] Alternatively: Other forms of recesses, e.g., indentations, rings, dents, etc.

[0025] In other words, the above-mentioned task is solved by a sensor plate for measuring force distributions, comprising:

[0026] - a sensor element with at least one sensor cell forming a discrete sensitive area,

[0027] - at least one pressure guide element which is connected and positioned with the sensor element for force transmission to the at least one sensor cell, wherein the pressure guide element has at least one pressure guide tunnel, wherein each sensor cell is assigned a pressure guide tunnel positioned on it, so that a surface-acting load is directed specifically and mainly 202403264 4 through one or more sensor cells, wherein the pressure guide tunnel has at least one recess.

[0028] Preferably, the recess is a slot, a depression, a ring or a dent.

[0029] Preferably, the recess has a recess depth of at least 25% of the maximum height of the pressure guide tunnel.

[0030] In particular, the pressure control tunnel has several recesses, especially 3 to 6 recesses.

[0031] Preferably, the recesses run essentially perpendicular to the main direction of the pressure guide tunnel.

[0032] Pressure-guiding studs, preferably with a linear contact surface on the side facing away from and / or towards the sensor. Preferably, a linear or elongated contact surface on the side facing away from the sensor and a larger, wider contact surface in the direction of the sensor cell. This can be achieved, for example, by an approximately trapezoidal shape.

[0033] In other words, the basic shape of the pressure guide tunnel preferably has a linear contact surface facing away from the sensor cell and a wider contact surface in the direction of the sensor cell.

[0034] Pressure-guiding element defined as a thin, planar plane with individual elevations in the form of pressure-guiding ridges, in size and shape such that it covers the sensor element at least largely, preferably completely, and thereby protects it. 202403264 5

[0035] In other words, the pressure-guiding element is preferably designed as a thin, planar plane with individual elevations in the form of pressure-guiding ridges that cover the sensor element at least mostly, preferably completely.

[0036] A reaction force measuring system with such a sensor plate.

[0037] A diagnostic system with such a reaction force measurement system and sensor signal transmission and reception unit, as well as a data processing unit and display on an end device.

[0038] In other words, the above-mentioned problem is also solved by a reaction force measuring system comprising a sensor plate according to one of the preceding claims.

[0039] In other words, the above-mentioned task is also solved by a diagnostic system comprising the previously described reaction force measurement system as well as a sensor signal transmission and reception unit, a data processing unit and a display on an end device.

[0040] This results in the following advantages:

[0041] Slitting increases the local pressure on the sensor element under the unslotted areas, while reducing the pressure under the slotted areas.

[0042] This allows the sensor element to be activated even at lower forces, thus extending the force range downwards.

[0043] At the same time, greater deflection and thus force are required to increase the pressure on the sensor even below the slotted areas. This allows the measurable force range to be extended, as the effective local pressure on the sensor changes over a larger force range and thus becomes measurable. 202403264 6

[0044] Applications include:

[0045] • Performance or stress assessment on humans for integration into shoes (e.g., work shoes for occupational health checks)

[0046] • Performance or stress assessment on other animals (e.g. camel racing)

[0047] • Determination of loads and load distributions at the support points of machines or systems

[0048] Exemplary embodiments and further advantages of the invention are explained below in connection with the following schematic figures. These show:

[0049] Figure 1 shows a schematic representation of a pressure guide tunnel of a sensor plate according to the invention in one embodiment;

[0050] Figure 2 shows a top view of the pressure control tunnel from Fig. 1;

[0051] Figure 3 shows a side view of a sensor plate (1) according to a further embodiment of the invention; and

[0052] Figure 4 shows an exploded view of a sensor plate (1 ) according to a further embodiment.

[0053] Figures 1 and 2 show a pressure guide tunnel 5, as it can be provided in a pressure guide element 4 of a sensor plate 1 according to the invention, as shown in Figures 3 or 4. Such a pressure guide tunnel 5 is assigned to each sensor cell 3 of the sensor element 2 of the sensor plate 1 and serves to direct a surface-acting load specifically and primarily through these sensor cells 3. 202403264 7

[0054] Figure 4 shows an exploded view of a sensor plate 1 with a pressure guide tunnel 5, which has a basic shape with a linear contact surface facing away from the sensor cell 3 and a wider contact surface facing the sensor cell 3. In other words, the pressure guide tunnel has

[0055] 5 an approximately trapezoidal cross-section.

[0056] It has been shown that load distribution can be optimized if the pressure guide tunnel 5 has at least one recess 6, as shown in Figures 1 and 2.

[0057] In the present case, four recesses 6 are provided, each designed as a slot-shaped indentation. Preferably, the recesses have

[0058] 6. The recesses have a depth of at least 25% of the maximum height of the pressure tunnel 5. The recesses 6 run essentially perpendicular to the main direction of the pressure tunnel 5.

[0059] As can be seen in Figure 4, the sensor plate 1 has a carrier plate 7 on which the sensor element 2 can be arranged. The sensor element 2 has a first carrier film 2a and at least one sensor cell 3. On a second carrier film 4a, the pressure guide element 4 with the pressure guide groove 5 is arranged. The pressure guide groove 5 ensures that a load applied to the sensor plate 1 from above is directed specifically and primarily through the associated sensor cells 3 below it.

[0060] Figure 3 shows a side view of a sensor plate 1 according to the invention, similar to Figure 4. The sensor element 2, located between the carrier plate 7 and the pressure guide element 4, has a connector outlet 8 for signal transmission. The connector outlet 8 is provided with a cable guard 9 and a sealing element 10.

Claims

202403264 8 Patent claims 1. Sensor plate (1 ) for measuring force distributions, comprising: - a sensor element (2) with at least one sensor cell (3) forming a discrete sensitive area, - at least one pressure guide element (4) which is connected and positioned with the sensor element (2) for force transmission to the at least one sensor cell (3), wherein the pressure guide element (4) has at least one pressure guide tunnel (5), wherein each sensor cell (3) is assigned a pressure guide tunnel (5) positioned on it, so that a surface-acting load is directed in a targeted and main manner through one or more sensor cells (3), wherein the pressure guide tunnel (5) has at least one recess (6).

2. Sensor plate (1) according to claim 1, wherein the recess (6) is a slot, a depression, a ring or a dent.

3. Sensor plate (1) according to claim 1 or 2, wherein the recess (6) has a recess depth of at least 25% of the maximum height of the pressure guide tunnel (5).

4. Sensor plate (1) according to one of the preceding claims, wherein the pressure guide tunnel (5) has several recesses (6), in particular 3 to 6 recesses (6).

5. Sensor plate (1) according to one of the preceding claims, wherein the recesses (6) extend substantially perpendicular to the main direction of the pressure guide tunnel (5).

6. Sensor plate (1) according to one of the preceding claims, wherein the basic shape of the pressure guide tunnel (5) is one facing away from the sensor cell (3). 202403264 9 linear contact area and a wider contact area in the direction of the sensor cell (3).

7. Sensor plate (1) according to one of the preceding claims, wherein the pressure guide element (4) is formed as a thin planar plane with individual elevations in the form of pressure guide ridges (5) which at least largely, preferably completely, cover the sensor element (2).

8. Sensor plate (1 ) according to one of the preceding claims, wherein the sensor element (2) is a pressure-sensitive resistive sensor element (2).

9. Sensor plate (1) according to any one of the preceding claims 1 to 7, wherein the sensor element (2) comprises electroactive polymers, capacitive sensors or inductive sensors.

10. Reaction force measuring system comprising a sensor plate (1 ) according to one of the preceding claims.

11. Diagnostic system comprising a reaction force measurement system according to claim 10 as well as a sensor signal transmission and reception unit, a data processing unit and a display on an end device.

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