Computing device, capacitive sensor, measuring cabinet and method for checking capacitive sensor

Abstract

The invention relates to a computing device (10) for a capacitive sensor, having an electronics system (10a) which is designed and / or programmed in such a way that the electronic system (10a) is designed and / or programmed, when the sensor mass (16) is in its initial position or in its initial vibration, at least one first measurement variable (C1) with respect to a first capacitance (C1) between the first electrode (14a) and the sensor mass (16) is taken into account, wherein the first measurement variable (C1) is determined or provided with respect to the first capacitance (C1) between the first electrode (14a) and the sensor mass (16). At least one evaluation variable relating to the distance of the sensor mass (16) from the first electrode (14a) and / or the second electrode (14b) and / or relating to a property of the sensor mass (16) and / or of the at least one spring element (18a, 18b) can be ascertained as at least part of evaluation information (20) by means of the electronics arrangement (10a). The invention also relates to a corresponding capacitive sensor, to a measuring cabinet for a production site, and to a method for inspecting a capacitive sensor.

Description

Field of the Invention

[0001] The present invention relates to a computing device for a capacitive sensor. The present invention also relates to a capacitive sensor and a measuring cabinet for a production site. In addition, the present invention further relates to a method for inspecting a capacitive sensor. Background Art

[0002] In the traditional way, after manufacturing a capacitive sensor, a final test is mostly carried out. For this purpose, at least one test measurement is carried out with the capacitive sensor, either by using a test device that realizes the corresponding test environment and / or test conditions, or by imitating the corresponding test situation by applying a non-zero voltage to the movable sensor mass of the capacitive sensor or by using a corresponding alternative stimulus, as disclosed in DE 10 2020 211 308 A1. Summary of the Invention

[0003] The present invention provides a computing device for a capacitive sensor, a capacitive sensor, a measuring cabinet for a production site, and a method for inspecting a capacitive sensor.

[0004] The present invention creates the possibility of determining at least one sensor-specific evaluation variable of a capacitive sensor without having to carry out a test measurement on the corresponding capacitive sensor in an artificially generated test environment and / or test conditions, and without having to imitate the corresponding test situation by applying at least one voltage to the movable sensor mass of the capacitive sensor or by using a corresponding alternative stimulus. Instead, implementing the present invention requires at most determining a first measurement variable of a first capacitance between a first electrode of the capacitive sensor and the sensor mass and / or a second measurement variable of a second capacitance between a second electrode of the capacitive sensor and the sensor mass, wherein the first measurement variable and the second measurement variable are respectively determined when the sensor mass is in its initial position or initial vibration. Therefore, determining the first measurement variable and / or the second measurement variable does not require a physical force external to the sensor to act on the sensor mass, and does not require a voltage to be applied between the first electrode and the sensor mass and / or between the second electrode and the sensor mass. Therefore, the first measurement variable and the second measurement variable can still be determined, while the test equipment required as in the prior art is not necessary for this. Therefore, implementing the present invention is particularly cost-effective and can be completed relatively quickly. In addition, only an electronic device designed and / or programmed for this purpose is required to implement the present invention. The test equipment can be dispensed with when implementing the present invention.

[0005] Preferably, the electronic device facility is additionally designed and / or programmed such that the at least one evaluation variable can be determined by means of the electronic device facility while additionally taking into account at least one second measurement variable of a second capacitance between the second electrode and the sensor mass when the sensor mass is in its initial position or initial vibration. This can improve the accuracy in determining the at least one evaluation variable.

[0006] In an advantageous embodiment of the computing device, the electronic device facility is additionally designed and / or programmed such that by means of the electronic device facility, at least the first actual distance of the sensor mass to the first electrode, the second actual distance of the sensor mass to the second electrode, the first actual deviation of the first actual distance of the sensor mass to the first electrode from the first intended distance of the sensor mass to the first electrode, the second actual deviation of the second actual distance of the sensor mass to the second electrode from the second intended distance of the sensor mass to the second electrode, the average value of the first actual distance and the second actual distance, and / or the deviation of the sensor mass from the intermediate spacing position relative to the first electrode and the second electrode can be determined as the at least one evaluation variable. The determination of the first actual distance, the second actual distance, the first actual deviation, the second actual deviation, the average value derived from the first actual distance and the second actual distance, and / or the deviation of the sensor mass from its intermediate spacing position relative to the first electrode and the second electrode described here can be implemented by means of a relatively low-cost electronic device facility.

[0007] Alternatively or additionally, the electronic device facility can be additionally designed and / or programmed such that by means of the electronic device facility, at least the etching intensity and / or etching degree of the sensor mass and / or at least one spring member can be determined as the at least one evaluation variable. Thus, the embodiments of the computing device described here can determine evaluation variables that are difficult to obtain in a conventional manner with relatively little effort.

[0008] Preferably, the electronic device facility is additionally designed and / or programmed such that by means of the electronic device facility, at least the average extension scale of the sensor mass in the spatial direction extending from the first electrode to the second electrode, the maximum extension scale of the sensor mass in the spatial direction extending from the first electrode to the second electrode, the volume of the sensor mass, and / or the weight of the sensor mass can be determined as the at least one evaluation variable. Thus, a large number of sensor-specific evaluation variables of the sensor mass of the corresponding electrical sensor can be determined by means of the embodiments of the computing facility described here.

[0009] Alternatively or additionally, the electronic device facility can be additionally designed and / or programmed such that, by means of the electronic device facility, at least the respective volume, the respective weight, the respective spring constant of the at least one spring member, and / or the total spring constant of the spring-mass system formed by the sensor mass and the at least one spring member can be determined as the at least one evaluation variable. Thus, by means of the embodiments of the computing facility described herein, the sensor-specific evaluation variables of the at least one spring member of the corresponding capacitive sensor can also be reliably determined.

[0010] In a particularly advantageous embodiment of the computing device, the electronic device facility is additionally designed and / or programmed such that, by means of the electronic device facility, at least the natural frequency of the spring-mass system formed by the sensor mass and the at least one spring member can be determined as the at least one evaluation variable. Thus, without performing a large number of laborious test measurements, the natural frequency of the spring-mass system formed by the sensor mass and the at least one spring member can be determined by means of the embodiments of the computing device / its electronic device facility described herein.

[0011] Preferably, the electronic device facility is additionally designed and / or programmed such that, by means of the electronic device facility, at least the sensitivity of the capacitive sensor can be determined as the at least one evaluation variable. Thus, without performing laborious test measurements, the sensitivity of the capacitive sensor can also be reliably determined by means of the embodiments of the computing device / its electronic device facility described herein.

[0012] The computing device can be, for example, an ASIC. Thus, the computing device can also be constructed in a cost-effective and relatively space-saving manner.

[0013] The aforementioned advantages are also ensured in such a capacitive sensor: the capacitive sensor is equipped with a computing device, a support, at least a first electrode fixed to and / or in the support, and a sensor mass, and the sensor mass is displaceably attached to the support and / or in the support by means of at least one spring member of the capacitive sensor such that the sensor mass can be displaced from its initial position or initial vibration by a physical force external to the sensor and / or by a non-zero voltage applied between the first electrode and the sensor mass and / or between a second electrode and the sensor mass of the capacitive sensor.

[0014] The capacitive sensor can in particular be an acceleration sensor, a capacitive pressure sensor, or a rotational speed sensor. Thus, the invention described herein can be utilized for frequently used sensor types. However, the constructability of the capacitive sensor is not limited to the sensor types listed herein.

[0015] The aforementioned advantages can also be achieved in a measuring cabinet with a corresponding computing device for a production site.

[0016] Furthermore, implementing the corresponding method for checking a capacitive sensor also achieves the advantages explained above. It should be expressly noted that the method for checking a capacitive sensor can be extended according to the embodiments of the computing device and / or the capacitive sensor explained above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features and advantages of the present invention are explained hereinafter with the aid of the drawings. The drawings show:

[0018] Figure 1 : a schematic diagram of an embodiment of a computing device or a capacitive sensor interacting therewith, and

[0019] Figure 2 : a flowchart for explaining an embodiment of a method for checking a capacitive sensor. DETAILED DESCRIPTION

[0020] Figure 1 A schematic diagram showing an embodiment of a computing device and a capacitive sensor interacting therewith.

[0021] In Figure 1The computing device 10 schematically described can cooperate with (almost) any capacitive sensor, which is at least equipped with a support 12, at least one first electrode 14a, and possibly a second electrode 14b and a sensor mass 16. The sensor mass 16, the first electrode 14a, and possibly also the second electrode 14b are each at least partially made of at least one conductive material. The first electrode 14a and possibly also the second electrode 14b are each to be understood as electrodes 14a and 14b fixed / non-displaceable on and / or in the support 12. In contrast, the sensor mass 16 refers to a displaceable mass or a vibrating mass, which is displaceably attached on and / or in the support 12 by means of at least one spring element 18a and 18b of the capacitive sensor such that the sensor mass 16 is displaceable / shifted out of its so-called initial position or initial vibration by a physical force external to the sensor and / or by a non-zero voltage applied between the first electrode 14a and the sensor mass 16 and / or between the second electrode 14b and the sensor mass 16. Thus, the sensor mass 16 and at least one spring element 18a and 18b form the spring-mass system of the capacitive sensor. By means of a physical force external to the sensor, the sensor mass 16 is displaceable / shifted out of its initial position or initial vibration, and this physical force external to the sensor can be understood as, for example, an inertial force, a pressure, or a Coriolis force. Thus, the capacitive sensor can in particular be an acceleration sensor, a capacitive pressure sensor, or a rotational speed sensor. However, it should be explicitly noted that the usability of the computing device 10 described below is not limited to a specific sensor type of the capacitive sensor.

[0022] Figure 1 The capacitive sensor only exemplarily has a first tension or compression spring 18a and a second tension or compression spring 18b, wherein the sensor mass 16 is suspended in a gimbaled manner between the first tension or compression spring 18a and the second tension or compression spring 18b. However, the constructability of the capacitive sensor cooperating with the computing device 10 is not limited to a specific spring type of at least one spring element 18a and 18b of the capacitive sensor.

[0023] The capacitive sensor can in particular be a MEMS (Micro-Electro-Mechanical-System) capacitive sensor or a micromechanical component. At least the sensor mass 16 and the at least one spring element 18a and 18b can each be components etched from a raw material, the shape of which depends correspondingly on the etching time and the (actual) etching intensity during the implementation of the corresponding etching step. The first electrode 14a and possibly also the second electrode 14b can be formed from at least one conductive material by means of a deposition step and / or a growth step. However, alternatively, the first electrode 14a and possibly also the second electrode 14b can also be components etched from a raw material, the shape of which depends correspondingly on the etching time and the (actual) etching intensity during the implementation of the corresponding etching step.

[0024] The computing device 10 can alternatively be a sub-unit of the capacitive sensor or interact with the capacitive sensor outside the sensor. For example, the computing device 10 can also be a sub-unit of a measuring cabinet at a production site where at least one of the capacitive sensors is manufactured. Therefore, the computing device 10 described below can be used in many ways. In addition, the computing device 10 described below can also be an ASIC. Therefore, the computing device 10 can be manufactured at relatively low cost. In such a computing device 10, the installation space requirement is also minimized.

[0025] The computing device 10 has an electronic device facility 10a which is designed and / or programmed such that, with the aid of this electronic device facility 10a, evaluation information 20 about the capacitive sensor can be determined / has been determined. With the aid of the electronic device facility 10a, the determination of the evaluation information 20 is carried out taking into account at least one measured variable C1 and C2 of the corresponding capacitances C1 and C2 between the first electrode 14a and the sensor mass 16 and / or between the second electrode 14b and the sensor mass 16. The at least one measured variable C1 and C2 can be determined by means of the computing device 10 or a correspondingly designed sub-unit of the computing device 10, or provided to the computing device 10.

[0026] In addition, the electronic device facility 10a is designed and / or programmed such that, by means of the electronic device facility 10a, at least one evaluation variable regarding the spacing between the sensor mass 16 and the first electrode 14a and / or the second electrode 14b and / or regarding the characteristics of the sensor mass 16 and / or at least one spring member 18a, 18b can be determined / is determined, as at least part of the evaluation information 20, taking into account at least one first measurement variable C1 of the first capacitance C1 between the first electrode 14a and the sensor mass 16, which is determined or provided when the sensor mass 16 is in its initial position or initial vibration. Optionally, the electronic device facility 10a can also be designed and / or programmed to determine the at least one evaluation variable additionally taking into account a second measurement variable C2 that is determined or provided when the sensor mass 16 is in its initial position or initial vibration. The second measurement variable C2 should be understood as a measurement variable of the second capacitance C2 between the second electrode 14b and the sensor mass 16. Examples of the at least one evaluation variable that can be determined by means of the electronic device facility 10a are listed below.

[0027] For example, as the at least one evaluation variable, at least the first actual distance d1 of the sensor mass 16 to the first electrode 14a, the first actual deviation Δd1 of the first actual distance d1 of the sensor mass 16 to the first electrode 14a, and / or the average value d obtained from the first actual distance d1 and the second actual distance d2 of the sensor mass 16 to the second electrode 14b m can be determined / is determined as at least part of the evaluation information 20. The first actual deviation Δd1 should be understood as the deviation between the first actual distance d1 and the first desired distance d 01 of the sensor mass 16 to the first electrode 14a (d1 = d 01 - Δd1). The average value d obtained from the first actual distance d1 and the second actual distance d2 m can be equal to half of the sum of the first actual distance d1 and the second actual distance d2 (d m = (d1 + d2) / 2).

[0028] Since at least the first measurement variable C1 is determined when no physical force external to the sensor acts on the sensor mass 16 and no voltage other than 0 is applied, at least between the first electrode 14a and the sensor mass 16 and possibly also between the second electrode 14b and the sensor mass 16 (because otherwise the sensor mass 16 would not be in its initial position or initial vibration), thus, if the first actual distance d1 is equal to the first desired distance d 01 , the first measurement variable C1 would correspond to a specific first measurement variable value. Therefore, the deviation of the first measurement variable C1 from this first measurement variable value is related to the first actual distance d1 and the first desired distance d01 is related to the first actual deviation Δd1. Thus, the relatively simple design / programming that can be implemented by means of the electronic device facility 10a can ensure that, by means of the electronic device facility 10a, the first actual distance d1 and / or the first actual deviation Δd1 can be determined relatively reliably and precisely while taking into account the first measurement variable C1. Since the knowledge of the first actual distance d1 often enables the second actual distance d2 to be deduced inversely, the average value d obtained from the first actual distance d1 and the second actual distance d2 can also be reliably determined according to the first capacitance C1 m .

[0029] It should also be pointed out here that the first measurement variable C1 can be measured in a low-cost manner without special operating expenses. Since it is not necessary for a physical force external to the sensor to act on the sensor mass 16 and no voltage application is required to measure the first measurement variable C1, no special and expensive test equipment is required to measure the first measurement variable C1 either. Thus, the computing device 10 described here realizes a low-cost and low-operating-expense possibility for determining / obtaining at least the first actual distance d1, the first actual deviation Δd1, or the average value d obtained from the first actual distance d1 and the second actual distance d2 m , as at least part of the evaluation information 20.

[0030] Additionally, if the sensor mass 16, at least one spring member 18a and 18b, the first electrode 14a, and possibly also the second electrode 14b are "just formed", the first measurement variable C1 can often also be reliably measured during the manufacturing process of the capacitive sensor. Thus, the computing device 10 can also be used to pre-check the capacitive sensor to be manufactured, so that when the first actual distance d1, the first actual deviation Δd1, and / or the average value d obtained from the first actual distance d1 and the second actual distance d2 m are respectively outside the pre-given normal value range, defects in the so far manufacturing of the capacitive sensor can be identified early, and the further processing of the capacitive sensor that may be meaningless can be abandoned. This is a major advantage of the computing device 10 compared to the traditional possibility of testing the capacitive sensor only after it is completely produced.

[0031] Correspondingly, the electronic device facility 10a can also be additionally designed and / or programmed to determine the second actual distance d2 from the sensor mass 16 to the second electrode 14b and / or the second actual deviation Δd2 of the second actual distance d2 from the sensor mass 16 to the second electrode 14b while taking into account at least the second measurement variable C2. The second actual deviation Δd2 should be understood as the difference between the second actual distance d2 and the second supposed distance d from the sensor mass 16 to the second electrode 14b 02The deviation (d2 = d 02 -Δd2). (Not mandatory: The second actual deviation Δd2 is equal to the negative of the first actual deviation Δd1, as depicted in Figure 1 .) If desired, it is also possible to determine the average value d obtained from the first actual distance d1 and the second actual distance d2, which is half of the sum of the asserted first actual distance d1 and the asserted second actual distance d2 m . Based on the first measurement variable C1 and the second measurement variable C2, it is also possible to reliably determine the deviation of the sensor mass 16 from the intermediate spacing position relative to the first electrode 14a and the second electrode 14b.

[0032] As already explained above, at least the sensor mass 16 and the at least one spring member 18a and 18b can each be a component etched from a raw material. As can be seen from the markings 22 in Figure 1 , not only the respective shapes of at least the sensor mass 16 and the at least one spring member 18a and 18b, but also correspondingly the first actual distance d1, the first deviation Δd1, the second actual distance d2, the second actual deviation Δd2, and the average value d obtained from the first actual distance d1 and the second actual distance d2 m all depend on the etching time and the (actual) etching intensity when structuring at least the sensor 16 and / or the at least one spring member 18a and 18b. Correspondingly, the first measurement variable C1, the second measurement variable C2, the first actual distance d1, the first actual deviation Δd1, the second actual distance d2, the second actual deviation Δd2, and the average value d obtained from the first actual distance d1 and the second actual distance d2 m are such variables that enable the etching time and the (actual) etching intensity when structuring at least the sensor 16 and / or the at least one spring member 18a and 18b to be deduced backwards. Therefore, the electronic device installation 10a can also be designed and / or programmed to determine the etching intensity and / or the etching degree of at least the sensor mass 16 and / or the at least one spring member 18a and 18b as the at least one evaluation variable.

[0033] Additionally, the first measurement variable C1, the second measurement variable C2, the first actual distance d1, the first actual deviation Δd1, the second actual distance d2, the second actual deviation Δd2, and the average value d obtained from the first actual distance d1 and the second actual distance d2 mMakes it possible to back-calculate the shape of at least the sensor mass 16 and at least one spring member 18a and 18b realized by means of said structuring (actual), and accordingly also to back-calculate the characteristics of at least the sensor mass 16 and at least one spring member 18a and 18b caused by their shape. Thus, by means of a simply implementable design and / or programming, the electronic device facility 10a can also be extended to at least determine the average extension scale of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b, the maximum extension scale a of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b max 、the volume of the sensor mass 16 and / or the weight / mass m of the sensor mass 16 16 , as said at least one evaluation variable. For the average extension scale of the sensor mass 16, the maximum extension scale a of the sensor mass 16 max 、the volume of the sensor mass 16 and / or the weight / mass m of the sensor mass 16 16 The determination of can be carried out in a simple manner by means of the electronic device facility 10a taking into account the first measurement variable C1, the second measurement variable C2, the first actual distance d1 of the sensor mass 16 to the first electrode 14a, the first actual deviation Δd1 of the first actual distance d1 from the first desired distance d 01 , the second actual distance d2 of the sensor mass 16 to the second electrode 14b, the second actual deviation Δd2 of the second actual distance d2 from the second desired distance d 02 and / or the average value d obtained from the first actual distance d1 and the second actual distance d2 m in the case. Thus, the sensor-specific data of the sensor mass 16 of the capacitive sensor can be obtained in a simple manner by means of the electronic device facility 10a.

[0034] Correspondingly, the electronic device facility 10a can also be constructed by means of a simply implementable design and / or programming to at least determine the volume of each of at least one spring member 18a and 18b, the weight / each mass of each of at least one spring member 18a and 18b, the spring constant of each of at least one spring member 18a and 18b and / or the total spring constant k of the spring-mass system formed by the sensor mass 16 and at least one spring member 18a and 18b H , as said at least one evaluation variable. (The total spring constant k of the spring-mass system H is sometimes also referred to as the Hooke's constant.) If necessary, for the volume of each of at least one spring member 18a and 18b, the weight / each mass of each of at least one spring member 18a and 18b, the spring constant of each of at least one spring member 18a and 18b and / or the total spring constant k of the spring-mass systemH is determined by means of the electronic device installation 10a taking into account the first measurement variable C1, the second measurement variable C2, the first actual distance d1 of the sensor mass 16 to the first electrode 14a, the first actual deviation Δd1 of the first actual distance d1 from the first nominal distance d 01 the second actual distance d2 of the sensor mass 16 to the second electrode 14b, the second actual deviation Δd2 of the second actual distance d2 from the second nominal distance d 02 and / or the average value d obtained from the first actual distance d1 and the second actual distance d2 m This is done. Thus, the electronic device installation 10a can also be used to obtain sensor-specific data on at least one of the spring elements 18a and 18b without performing laborious measurements.

[0035] In another advantageous embodiment, the electronic device installation 10a is additionally designed and / or programmed such that, as at least one of the evaluation variables, the natural frequency f0 of the spring-mass system formed by the sensor mass 16 and at least one of the spring elements 18a and 18b can also be determined / is determined by means of the electronic device installation 10a as part of the evaluation information 20. The natural frequency f0 of the spring-mass system can also be determined by means of the electronic device installation 10a taking into account the first measurement variable C1, the second measurement variable C2, the first actual distance d1 of the sensor mass 16 to the first electrode 14a, the first actual deviation Δd1 of the first actual distance d1 from the first nominal distance d 01 the second actual distance d2 of the sensor mass 16 to the second electrode 14b, the second actual deviation Δd of the second actual distance d2 from the second nominal distance d 02 the second actual deviation Δd 2、 the average value d obtained from the first actual distance d1 and the second actual distance d2 m the average extension scale of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b, the maximum extension scale a of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b max the volume of the sensor mass 16, the weight / mass m of the sensor mass 16 16 the volume of each of the at least one spring element 18a and 18b, the weight / respective mass of each of the at least one spring element 8a and 18b, the spring constant of each of the at least one spring element 8a and 18b and / or the total spring constant k of the spring-mass system H This is determined because the variables listed here allow the natural frequency f0 of the spring-mass system to be deduced backwards. In particular, the natural frequency f0 of the spring-mass system can be determined by means of the electronic device installation 10a using the following equation (Equation 1):

[0036] (Formula 1)

[0037] Advantageously, the electronic device facility 10a can also be additionally designed and / or programmed such that, by means of the electronic device facility, the sensitivity S of the capacitive sensor can be determined / is determined as the at least one evaluation variable. In particular, when considering the first measurement variable C1, the second measurement variable C2, the first actual distance d1 of the sensor mass 16 to the first electrode 14a, the first actual deviation Δd1 of the first actual distance d1 from the first nominal distance d 01 the second actual distance d2 of the sensor mass 16 to the second electrode 14b, the second actual deviation Δd2 of the second actual distance d2 from the second nominal distance d 02 the average value d obtained from the first actual distance d1 and the second actual distance d2 m the average extension scale of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b, the maximum extension scale a of the sensor mass 16 along the spatial direction 24 extending from the first electrode 14a to the second electrode 14b max the volume of the sensor mass 16, the weight / mass m of the sensor mass 16 16 the volume of each of the at least one spring member 18a and 18b, the weight / each mass of the at least one spring member 8a and 18b, the spring constant of each of the at least one spring member 8a and 18b, the total spring constant k of the spring-mass system H and / or in the case of the natural frequency f0 of the spring-mass system, the sensitivity S of the capacitive sensor can be reliably determined. For example, the determination of the sensitivity S of the capacitive sensor can be carried out by means of the electronic device facility 10a using the following equation (Formula 2):

[0038] (Formula 2)

[0039] These evaluation variables that can be reliably and precisely determined as evaluation information 20 by means of the computing device 10 / its electronic device facility 10a are significant characteristics of the capacitive sensor. Subsequently, by virtue of the knowledge of these characteristics, the capacitive sensor can be operated such that at least one physical measurement variable to be measured by means of the capacitive sensor, such as acceleration and / or rotational speed, can be determined with relatively high precision and with a relatively low error rate.

[0040] The computing device 10 can also advantageously be used for spring-mass systems with a complex structure. If necessary, calculation rules corresponding to the said equations (Formula 1 and Formula 2) can be used to obtain structural information and, if desired, the corresponding asymmetry and / or the corresponding sensitivity S can be deduced backwards. Thus, the capacitance of the capacitive sensor inFigure 1 The relatively simple configurations shown should only be construed as exemplary. Since the calculation rules corresponding to these equations (Equations 1 and 2) are known from the prior art, they will not be discussed in greater depth here.

[0041] Figure 2 A flowchart showing an embodiment of a method for explaining a method for checking a capacitive sensor is shown.

[0042] When implementing the method explained here, evaluation information is determined taking into account at least one determined measurement variable. At least one determined measurement variable should be understood as a variable regarding the corresponding capacitance between at least a first electrode and / or a second electrode fixed on and / or in a support of the capacitive sensor and the sensor mass of the capacitive sensor, wherein the sensor mass is displaceably attached to the support by means of at least one spring element of the capacitive sensor such that the sensor mass can be displaced / shifted out of its initial position or initial vibration by means of a physical force external to the sensor and / or by means of a non-zero voltage applied between the first electrode and the sensor mass and / or between the second electrode and the sensor mass. Examples have been listed above for the physical force external to the sensor.

[0043] The method has a method step S1, in which, when the sensor mass is in its initial position or initial vibration, at least a first measurement variable regarding the first capacitance between the first electrode and the sensor mass is determined. In a subsequent method step S2, at least one evaluation variable regarding the spacing between the sensor mass and the first electrode and / or the second electrode and / or regarding the properties of the sensor mass and / or at least one spring element is determined as at least part of the evaluation information, taking into account at least the determined first measurement variable. Examples have been listed above for the at least one evaluation variable. Thus, the method described here also offers the advantages explained above, wherein the method can be extended according to Figure 1 an example of a computing device.

Claims

1. A computing device (10) for a capacitive sensor, having: an electronic device facility (10a), which is designed and / or programmed such that, by means of the electronic device facility (10a), it is possible to determine evaluation information (20) taking into account at least one measurement variable (C1, C2) of a corresponding capacitance (C1, C2) between at least a first electrode (14a) and / or a second electrode (14b) fixed on and / or in a support (12) of the capacitive sensor and the sensor mass (16) of the capacitive sensor, the sensor mass being attached in a displaceable manner to the support (12) on and / or in the capacitive sensor by means of at least one spring member (18a, 18b) of the capacitive sensor such that the sensor mass (16) can be displaced from its initial position or initial vibration by a physical force external to the sensor and / or by means of a non-zero voltage applied between the first electrode (14a) and the sensor mass (16) and / or between the second electrode (14b) and the sensor mass (16); characterized in that the electronic device facility (10a) is designed and / or programmed such that, by means of the electronic device facility (10a), at least one evaluation variable regarding the spacing between the sensor mass (16) and the first electrode (14a) and / or the second electrode (14b) and / or regarding the characteristics of the sensor mass (16) and / or of the at least one spring member (18a, 18b) can be determined as at least part of the evaluation information (20) taking into account at least one first measurement variable (C1) of the first capacitance (C1) between the first electrode (14a) and the sensor mass (16) determined or provided when the sensor mass (16) is in its initial position or initial vibration.

2. The computing device (10) according to claim 1, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that the at least one evaluation variable can be determined by means of the electronic device facility (10a) additionally taking into account at least one second measurement variable (C2) of the second capacitance (C2) between the second electrode (14b) and the sensor mass (16) determined or provided when the sensor mass (16) is in its initial position or initial vibration.

3. The computing device (10) according to claim 1 or 2, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that by means of the electronic device facility (10a), at least the first actual distance (d1) of the sensor mass (16) to the first electrode (14a), the second actual distance (d2) of the sensor mass (16) to the second electrode (14b), the first actual deviation (Δd1) of the first actual distance (d1) of the sensor mass (16) to the first electrode (14a) from the first desired distance (d 01 ) of the sensor mass (16) to the first electrode (14a), the second actual deviation (Δd2) of the second actual distance (d2) of the sensor mass (16) to the second electrode (14b) from the second desired distance (d 02 ) of the sensor mass (16) to the second electrode (14b), the average value (d m ) derived from the first actual distance (d1) and the second actual distance (d2), and / or the deviation of the sensor mass (16) from the intermediate spacing position relative to the first electrode (14a) and the second electrode (14b) are determined as the at least one evaluation variable.

4. The computing device (10) according to one of the above claims, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that, by means of the electronic device facility (10a), at least the etching intensity and / or etching degree of the sensor mass (16) and / or of the at least one spring member (18a, 18b) can be determined as the at least one evaluation variable.

5. The computing device (10) according to one of the above claims, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that, by means of the electronic device facility (10a), at least the average extension scale of the sensor mass (16) along the spatial direction (24) extending from the first electrode (14a) to the second electrode (14b), the maximum extension scale (a max ) of the sensor mass (16) along the spatial direction (24) extending from the first electrode (14a) to the second electrode (14b), the volume of the sensor mass (16), and / or the weight (m 16 ) of the sensor mass (16) can be determined as the at least one evaluation variable.

6. The computing device (10) according to one of the above claims, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that at least the respective volume of the at least one spring member (18a, 18b), the respective weight of the at least one spring member (18a, 18b), the respective spring constant of the at least one spring member (18a, 18b), and / or the total spring constant (k H ) of the spring-mass system formed by the sensor mass (16) and the at least one spring member (18a, 18b) can be determined as the at least one evaluation variable.

7. The computing device (10) according to one of the above claims, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that at least the natural frequency (f0) of the spring-mass system formed by the sensor mass (16) and the at least one spring element (18a, 18b) can be determined by means of the electronic device facility (10a) as the at least one evaluation variable.

8. The computing device (10) according to one of the above claims, wherein, The electronic device facility (10a) is additionally designed and / or programmed such that at least the sensitivity (S) of the capacitive sensor can be determined by means of the electronic device facility (10a) as the at least one evaluation variable.

9. The computing device (10) according to one of the above claims, wherein, The computing device (10) is an ASIC.

10. A capacitive sensor, comprising: The computing device (10) according to one of the preceding claims; A support (12); At least one first electrode (14a) fixed on and / or in the support (12); and A sensor mass (16) which is attached to the support (12) in a displaceable manner by means of the at least one spring element (18a, 18b) of the capacitive sensor such that the sensor mass (16) can be displaced from its initial position or initial vibration by a physical force external to the sensor and / or by means of a non-zero voltage applied between the first electrode (14a) and the sensor mass (16) and / or between the second electrode (14b) of the capacitive sensor and the sensor mass (16).

11. The capacitive sensor according to claim 10, wherein, The capacitive sensor is an acceleration sensor, a capacitive pressure sensor or a rotational speed sensor.

12. A measuring cabinet for a production site, having the computing device (10) according to one of claims 1 to 9.

13. A method for checking a capacitive sensor, having the following steps: Determining evaluation information (20) taking into account at least one measurement variable (C1, C2) of the capacitance (C1, C2) determined for the at least one first electrode (14a) and / or second electrode (14b) fixed on and / or in the support (12) of the capacitive sensor and the sensor mass (16) of the capacitive sensor, the sensor mass being attached to the support (12) in a displaceable manner by means of the at least one spring element (18a, 18b) of the capacitive sensor such that the sensor mass (16) can be displaced from its initial position or initial vibration by a physical force external to the sensor and / or by means of a non-zero voltage applied between the first electrode (14a) and the sensor mass (16) and / or between the second electrode (14b) and the sensor mass (16); Characterized in that Based on at least one first measurement variable (C1) of a first capacitance (C1) between the first electrode (14a) and the sensor mass (16), determined when the sensor mass (16) is in its initial position or initial vibration, an evaluation variable regarding the spacing between the sensor mass (16) and the first electrode (14a) and / or the second electrode (14b) and / or regarding the characteristics of the sensor mass (16) and / or the at least one spring element (18a, 18b) is determined (S2) as at least part of the evaluation information (20).

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