阅读说明：本技术 确定电容式多路径力传感器组件的操纵单元的偏移的方法 (Method for determining the offset of a steering unit of a capacitive multi-path force sensor assembly ) 是由 马克·舒尔珀 马蒂亚斯·塞弗特 于 2019-01-04 设计创作，主要内容包括：本发明涉及一种用于确定电容式的多路径力传感器组件的操纵单元的偏移的方法,该多路径力传感器组件具有可从其中性位置沿至少两个操纵方向调节的操纵单元,该操纵单元在取消操纵力时又移回到其中性位置,并且与该操纵单元连接有中央电容器板,该中央电容器板在操纵单元的静止位置中与至少一个位置固定的第一和第二电容器板间隔,并且通过调节操纵单元,向着至少一个位置固定的第一电容器板移动并且从至少一个第二电容器板移离,并且其中为了产生代表操纵单元的偏移的传感器值,使用至少一个通过带有至少一个位置固定的第一电容器板的中央电容器板形成的测量电容器,根据本发明,其特征在于,将位置固定的第一电容器板(3)保持在地电位上,使得在持续应用的积分方法中在多个彼此相继的周期内分别进行：-将中央电容器板以及至少位置固定的第二电容器板与不同于地电位的电压电位连接并且然后又与该电压电位分离,-将存储在中央电容器板上的电荷量传输到具有已知电容值的积分电容器上,并且在预给定数量的周期之后,借助A/D转换器测量积分电容器上的电压并且将其处理成第一传感器值。(The invention relates to a method for determining an offset of an actuating unit of a capacitive multi-path force sensor arrangement having an actuating unit which can be adjusted from its neutral position in at least two actuating directions, which actuating unit, when an actuating force is removed, moves back into its neutral position and to which a central capacitor plate is connected which, in the rest position of the actuating unit, is spaced apart from at least one first and one second fixed capacitor plate and, by adjusting the actuating unit, is moved toward and away from the at least one first fixed capacitor plate, and wherein, for generating a sensor value which represents an offset of the actuating unit, at least one measuring capacitor formed by the central capacitor plate with the at least one first fixed capacitor plate is used, according to the invention, the first fixed capacitor plate (3) is held at ground potential, so that in a continuously applied integration method in a plurality of successive cycles: the central capacitor plate and the at least stationary second capacitor plate are connected to a voltage potential different from ground potential and then separated again from this voltage potential, the charge stored on the central capacitor plate is transferred to an integrating capacitor with a known capacitance value, and after a predetermined number of cycles, the voltage on the integrating capacitor is measured by means of an a/D converter and processed into a first sensor value.)

1. A method for determining an offset of a actuating unit (1) of a capacitive multi-path force sensor arrangement having an actuating unit (1) which can be adjusted from its neutral position in at least two actuating directions, which actuating unit moves back into its neutral position when an actuating force is cancelled, and a central capacitor plate (2) which is spaced apart from at least one fixed first and second capacitor plate (3, 4) in a rest position of the actuating unit (1) and which is moved toward the at least one fixed first capacitor plate (3) and away from the at least one fixed second capacitor plate (4) by adjusting the actuating unit (1), and wherein, in order to generate a first sensor value which represents an offset which has moved away from the actuating unit (1), using at least one measuring capacitor formed by the central capacitor plate (2) and at least one fixed first capacitor plate (3),

-holding the first capacitor plate (3) in a fixed position at ground potential,

in the integration method used in succession, in each case:

-connecting the central capacitor plate (2) and at least the second capacitor plate (4) which is fixed in position to a voltage potential different from ground potential and then separated again from the voltage potential,

-transferring the amount of charge stored on the central capacitor plate (2) to an integrating capacitor having a known capacitance value,

and after a predetermined number of cycles, measuring the voltage across the integrating capacitor by means of an A/D converter and processing said voltage into the first sensor value.

2. Method according to claim 1, characterized in that in the rest position of the handling unit (1) the central capacitor plate (2) is at substantially the same distance from the first and second fixed capacitor plates (3, 4) and is moved by adjustment of the handling unit (1) to the same extent towards the first fixed capacitor plate (3) and away from the second fixed capacitor plate (4).

3. Method according to claim 1 or 2, characterized in that for generating a second sensor value representing the deflection of the steering unit (1), a measuring capacitor formed by the central capacitor plate (2) and the second capacitor plate (3) fixed in position is used.

4. Use of a method according to any one of claims 1 to 3 for determining an offset of a steering element (1) of a capacitive multipath force sensor assembly having a steering element (1) which is adjustable along one axis in both steering directions from its neutral position.

5. Use of a method according to one of claims 1 to 3 for determining an offset of a actuating unit (1) of a capacitive multipath force sensor assembly having an actuating unit (1) which can be adjusted from its neutral position in four actuating directions about two mutually perpendicular axes.

Technical Field

The present invention relates to a method for determining an offset of a steering element of a capacitive multi-path force sensor assembly, the multipath force sensor assembly has a steering unit adjustable from its neutral position in at least two steering directions, the actuating unit is moved back into its neutral position when the actuating force is removed, and a central capacitor plate is connected to the actuating unit, which in the rest position of the actuating unit is spaced from at least one stationary first and second condenser plate, and by adjusting the actuating unit, towards the at least one first condenser plate, which is fixed in position, and away from the at least one second condenser plate, and wherein for generating a sensor value representing the deflection of the actuating unit at least one measuring capacitor formed by a central capacitor plate with at least one first capacitor plate which is fixed in position is used.

Background

Multipath force sensor assemblies of the type described here are used, for example, in motor vehicles as universally usable components for the construction of more or less complex switching devices.

The force sensor arrangement is preferably designed, for example, as a bidirectional or four-way force sensor arrangement and is mounted on a common circuit board, which is accommodated in a housing of a handling grip block having an actuating surface associated with the force sensor arrangement.

Multipath force sensor assemblies used in such switchgear use capacitive sensors arranged in pairs in opposition to measure force in one or both axes. The sensors are each formed by a fixed capacitor plate and a capacitor plate which is assigned to the capacitor plate and can be displaced by means of the actuating unit. Specific capacitance measurements are derived from the distance of the displaceable capacitor plate from each stationary capacitor plate, with the aid of which a displacement can be inferred, and the force applied to the actuating unit can be inferred indirectly by means of a mechanical structure-based force-displacement-characteristic line. The respective capacitance value is inversely proportional to the distance of the respective capacitor plates, and a symmetry of their characteristic lines, i.e. a correlation of the measured values with the respective offset of the actuating unit, results with respect to oppositely arranged capacitors which "share" the common central capacitor plate. Thus, when a positive and a negative offset respectively takes place with respect to the steering unit and the axis of the capacitor plates connected to the steering unit, the substantially "same" portions of the characteristic line are always relevant, once with respect to the capacitor plates fixed in one position and once with respect to the capacitor plates fixed in the other position.

Disclosure of Invention

The method according to the invention for operating a capacitive multi-path force sensor arrangement offers a particularly cost-effective and reliable possibility for determining the sought-for sensor value which represents the respective offset of the actuating unit.

This is achieved according to the invention in that the first, fixed-position capacitor plate is held at ground potential, i.e. in the case of a continuously applied integration method in each case in a plurality of successive cycles:

connecting the central capacitor plate and the at least stationary second capacitor plate to a voltage potential different from ground potential and then again separated from the voltage potential,

transferring the amount of charge stored on the central capacitor plate to an integrating capacitor having a known capacitance value,

and after a predetermined number of cycles, the voltage across the integrating capacitor is measured by means of an a/D converter and processed into a sensor value.

The electrical multi-path switching assembly according to the invention can be advantageously used as a quasi-force-sensitive switching assembly, precisely in applications in which only a very small deflection of the actuating lever is desired or allowed and which achieve a certain actuating force setting as an important criterion for triggering the switching signal.

In a preferred embodiment of the method according to the invention, in the rest position of the operating unit the central condenser plate is at substantially the same distance from the first and second fixed condenser plates and is moved by adjustment of the operating unit to the same extent towards the first fixed condenser plate and away from the second fixed condenser plate.

Drawings

The invention is explained below with reference to the drawings.

Shown here are:

figure 1 is a schematic view of a capacitive multi-path force sensor assembly with a steering unit adjustable in two directions along an axis arranged for applying the method according to the invention,

fig. 2 is a schematic illustration of a capacitive multi-path force sensor assembly with a steering unit pivotably arranged about two mutually perpendicular axes, provided for applying the method according to the invention.

Detailed Description

In the example shown in fig. 1, the steering unit 1 can be adjusted along an axis in two directions. The two outer, fixed-position capacitor plates 3, 4 are electrically connected to the conductor paths of the circuit board 5 and are arranged with their main faces perpendicular to the circuit board. Between the two fixed capacitor plates 3, 4, there is a central capacitor plate 2 which can be adjusted by means of the actuating unit 1 in both directions along an axis parallel to the circuit board 5 and perpendicular to the main surfaces of the capacitor plates 2, 3, 4 and which is likewise electrically connected to the conductor paths of the circuit board 5.

The central capacitor plate 2 connected to the actuating unit 1 is at the same distance from the two outer, fixed-position capacitor plates 3, 4 in its rest position. Adjustment of the actuating unit 1 from this rest position in one direction causes the central condenser plate 2 to move to the same extent towards one of the two outer fixed-position condenser plates 4 and away from the other fixed-position condenser plate 3. The central capacitor plate 2 and the two outer capacitor plates 3, 4 form a measuring capacitor, whose capacitance values are used to generate two different sensor values that represent the deflection of the actuating unit.

The method according to the invention is used here by first holding the first of the two stationary condenser plates 3 at ground potential. The central capacitor plate 2 connected to the actuating unit 1 and the stationary second capacitor plate 4 are then connected to a voltage potential different from ground potential and subsequently separated again from this voltage potential, and the charge quantity stored on the central capacitor plate 2 is subsequently transferred to an integrating capacitor having a known capacitance value. In the case of a continuously applied integration method, these steps are carried out in a plurality of successive cycles, and after a predetermined number of cycles, the voltage at the integration capacitor is measured by means of an a/D converter and processed to a first sensor value which represents the offset of the actuating unit.

The same method is then immediately carried out again, wherein the roles of the two fixed-position capacitor plates 3, 4 are however interchanged, that is to say the fixed-position capacitor plate 3, which was previously held at ground potential, is now connected to a voltage potential different from ground potential, which is the same as the voltage potential of the central capacitor plate, and vice versa. After the execution of the just described steps of the integration method, the voltage at the integration capacitor is also measured after a predetermined number of cycles by means of the a/D converter and processed to a second sensor value representing the same offset of the actuating unit.

The first and second sensor values determined in this way represent the same offset of the actuating unit 1, each with opposite signs, so that in practice a redundant detection of this offset is achieved, which can be used to increase the reliability.

In the example shown in fig. 2, the steering unit 1 is arranged pivotable about two mutually perpendicular axes. The central capacitor plate 2 connected to the actuating unit 1 is at the same distance in the rest position of the actuating unit 1 from the four fixed capacitor plates 3, 3 ', 4' arranged opposite the central capacitor plate on the circuit board 5. Two of these fixed capacitor plates 3, 3 ', 4' form a first pair 3, 4 assigned to the pivoting of the actuating unit 1 about a first axis, and the other two capacitor plates form a second pair 3 ', 4' assigned to the pivoting of the actuating unit 1 about a second axis perpendicular to the first axis.

Pivoting of the actuating unit 1 about the first axis from the rest position causes the central condenser plate 2 to move to the same extent towards one of the two condenser plates 4 associated with the pivoting and away from the other condenser plate 3.

The central capacitor plate 2 forms a measuring capacitor together with the two fixed capacitor plates 3, 4, respectively, the capacitance value of which is used to generate a sensor value that represents the offset of the actuating unit 1. The pivoting of the actuating unit 1 about the first axis causes virtually no change with respect to the other two positionally fixed capacitor plates 3 ', 4' associated with the pivoting about the second axis.

As described above with respect to the single-shaft embodiment in fig. 1, the method according to the invention is applied here by first holding the first capacitor plate of the two stationary capacitor plates 3 associated with a pivot about the first axis at ground potential. The central capacitor plate 2 connected to the actuating unit and in this case all the remaining three fixed-position capacitor plates 3 ', 4' are then connected to a voltage potential different from ground potential and subsequently separated again from this voltage potential, and the charge stored on the central capacitor plate 2 is then transferred to an integrating capacitor having a known capacitance value.

The other steps of the process are carried out as described above for the single-axis embodiment, mutatis mutandis.

In this type of measurement, exactly one fixed capacitor plate is always held at ground potential, and the remaining fixed capacitor plates operate as active shields by: these capacitor plates are charged to the same potential as the movable central capacitor plate 2. The capacitor surface connected as a shield is virtually "invisible" for the capacitance measurement due to the equality of the potential of the central capacitor plate 2 and therefore does not contribute significantly to the capacitive distance measurement.