DE102016007057A1 - Device for detecting movement and gravitational acceleration and a sensor used thereby - Google Patents

Abstract

The invention relates to a sensor (1) with a base plate (3) and with a mass element (4) which is supported on the base plate (3) by a supporting element (6) having at least two sections (6.1, 6.2), the first one Section (6.1) of the support element (6) in the base plate (3) is clamped and elastically deformable and the support element (6) has a measuring point (8), wherein the second portion (6.2) is rigid, at an angle (β) is rigidly connected to the first section (6.1) and carrier of the mass element (4).

Description

The invention relates to a sensor whose reaction characteristic deviates significantly from the sinusoidal shape in the case of gravitational forces, and to a device for the separate detection of static and dynamic acceleration components using the sensor.

In a conventional sensor, the deflection of a spring-mounted mass element, for. B. on an elastic strip, a measure of the force acting on the mass. Whether this force can be assigned to a dynamic acceleration - longitudinal and lateral acceleration - or a static acceleration - a gravitational influence - or a superposition of both influences can not be recognized.

Even if several conventional sensors are used in different angular positions, the components of the dynamic acceleration and the gravitational acceleration can not be isolated by offsetting the output signals, since no new information is added due to the characteristic equality with sinusoidal characteristic. If the output signals of the sensors were calibrated for the same acceleration reactions and subtracted from each other, not only the dynamic acceleration components but also the static components, the gravitational components, would be compensated.

A device for the separate detection of dynamic and static acceleration components is known from WO 2012/013627 A1 known. This device has at least one base plate and at least two mass elements, wherein each mass element is connected via an elastic support element to the at least one base plate and the support elements each have at least one measuring point. The support elements of at least one first and at least one second mass element are designed such that the support element of the at least one first mass element and the support element of the at least one second mass element in the measuring points with respect to a first, acting in a first direction component of an acceleration the same reaction characteristic and in a perpendicular to the first component acting second component of the acceleration of each other have different reaction characteristics. The deflection of the measuring points of a first and a second support element is detected and evaluated by a mathematical elimination of the acceleration components contained in these measurements takes place, such that initially by pairwise mathematical combination of two sensors, the acceleration forces are eliminated in the longitudinal direction and then by mathematically linking the From these pairs of acceleration values, the vertical acceleration is eliminated so that the gravitational acceleration remains as an isolated quantity, in the knowledge of which the vertical acceleration and subsequently the longitudinal acceleration are retrogressively determined.

The sensors used here, which satisfy the condition for one of the acceleration forms dynamically or statically same and for the other form of acceleration have a different reaction characteristics, consist of an elastic rod or strip and an angled or bent elastic rod or strip, each with a measuring element on End and placed at an angle to the ground plane, these bars or strips are arranged in pairs and gel-like gel.

It has now been shown that the concrete in the WO2012 / 013 627 A1 named sensors have a comparatively small resolution, since the difference values in the reaction characteristics are small.

In order to increase the difference values in the reaction characteristics, which leads to a higher resolution and thus to improved measured value accuracy, in the DE 10 2014 009 003 A1 proposed a sensor system comprising a base plate and at least three mass elements, each mass element via an elastic support member connected to the base plate and deflected in the common plane or the parallel planes, wherein at least the support element of a mass element is a rod or strip, the is arranged so that the gravitational characteristic has a symmetrical sinusoidal characteristic and has a measuring point and the support elements of the other mass elements mirror-inverted same at least twice bent rods or strips are with measuring points away from the mass elements and an evaluation of the signals generated at the measuring points.

Characteristic of the aforementioned sensors of the device is that they maintain a substantially sinusoidal characteristic, but with lateral flattening, from whose difference then the measured value for the gravitational acceleration can be generated. The lateral flattening is the result of deflected forces. Other elastic strips for mass support only lead to slightly larger deformations. This type of influence of the gravitational force by angled elastic strips can therefore be characterized as a passive measure.

The object of the invention is to propose a sensor and a sensor system which has or at least one sensor has a considerably higher gravitational characteristic deviating from the sinusoid than is possible with the above-mentioned passive measures, so as to enable the resolution of the dynamic quantities of a movement. namely acceleration of motion in the longitudinal, transverse (relative to the sensor) and gravitational acceleration to improve.

The measures can be described as an active influence, as shown below.

This object is achieved by a sensor with the features of claim 1 and a device in the form of a sensor arrangement with the features of claim 8. Advantageous embodiments are the subject of the dependent claims.

The sensor according to the invention with a base plate and with a mass element, which is supported on the base plate by a support member having at least two sections, wherein the first portion of the support element is clamped in the base plate and elastically deformable and the support element has a measuring point, characterized in that the second section is rigidly formed, rigidly connected to the first section at an angle (β) and carries the mass element.

The sections of the support element are in mechanical or micromechanical design preferably rods or strips.

The sensor according to the invention thus consists in this preferred embodiment of a supported on a base plate two-piece strip structure, at the end of which the mass element is, wherein the strip part connected to the base plate is elastic and rigidly connected to this strip part second strip portion is designed and the measuring point can be located at any point of the strip parts, as well as at a further attached at the junction rigid strip.

Preferably, the measuring point is where the deformation, i. H. the deviation of the strip parts from the rest position is most clearly recognizable.

The angle (β) between the first and the second section of the support element is in an advantageous embodiment an acute angle, preferably in the range 5 ≦ β ≦ 60 °.

• – Ein Krafteinfluss, welcher den elastisch verformbaren Abschnitt verschiebt analog wie bei einem konventionellen Sensor, auf den eine Kraft wirkt (Versatzkomponente VK) und
• – ein Krafteinfluss, der infolge der Starrheit des starren Abschnittes als Moment eine Biegung des elastischen Abschnittes bewirkt (Richtungskomponente RK).

When the sensor is angled, two oppositely directed force influences are transmitted to the elastically deformable section via the rigid section as a result of the effective gravitational force component:

• - A force influence, which shifts the elastically deformable portion analogous as in a conventional sensor on which a force acts (offset component VK) and
• - A force influence, which causes due to the rigidity of the rigid portion as a moment bending of the elastic portion (directional component RK).

Since the characteristic curve of this directional influence, the measurement deflection curve generated by it, is different from that of the sinusoidal profile of the offset component, the sum of the two characteristic curves, the gravitational characteristic curve, also has a non-sinusoidal profile.

By changing the angle (β) between the two sections, the size of both force influences and thus their characteristics can be changed. In order to achieve the greatest possible deviation from a sinusoidal shape, the courses are dimensioned such that the highest possible compensation occurs in one quadrant and the lowest possible compensation in the adjacent quadrants.

A further advantageous embodiment provides that the rigid second portion of the support element has a greater length than the elastic first portion.

Due to the fixed connection of the elastic and rigid section, the direction of the rigid section at the transition point is taken over by the elastic section, as a result of which, as will be explained below, the gravitational characteristic curve is influenced, in particular at the end of the rigid section.

With flexible connection of lever and elastic section, the angle between them would increase in proportion to the applied force. In the case of the rigid connection according to the invention, however, this angle remains constant, as a result of which, in addition to the displacement of the connection region, a rotation of this region takes place when force is applied. With increasing deformation force caused by this rotation counterforce increases disproportionately due to the decreasing radius of curvature elastic section. As a result, the measurement deflections increase less than proportional to the force, as a result of which characteristic curves are flattened, that is to say a non-sinusoidal gravitational characteristic is produced. The influence caused by the twist is directly on the Section transition point hardly recognizable, here is a nearly sinusoidal gravitational characteristic.

If a further mass element is arranged on the elastically deformable first section, longitudinal acceleration components can be advantageously suppressed, which additionally reduces the metrological expenditure.

According to the invention, a device for detecting static and dynamic acceleration components is proposed which has at least:
In a measuring plane or in parallel measuring planes mirror-image arranged sensors as described above and a sensor of a base plate, an elastic support element with mass element and a measuring point, wherein the gravitational characteristic has a symmetrical sinusoidal characteristic, and an evaluation unit.

By a mathematical elimination of the measured values obtained in the measuring points for the dynamic as well as static acceleration components, eg. B. in such a way that the acceleration forces in the longitudinal direction are first eliminated by pairwise mathematical combination of two sensors and then the mathematical combination of the values obtained from these acceleration pairs, the vertical acceleration is eliminated, remains as an isolated size, the gravitational acceleration, in their knowledge, the vertical acceleration and then the Longitudinal acceleration be reckoned. The fact that two sensors have a significantly different from the sinusoid gravity curve, a significantly higher resolution is achieved.

If the device of the sensor arrangement is to be micromechanically embodied, the three-dimensional microstructure of the sensors is formed in a wall of a carrier material and well walls form the base plate or the microstructure of the sensors takes place in a frame of the carrier material or in a frame for each sensor, one or two parallel Frame sides respectively form the base plate.

The invention will be explained with reference to the drawings. Show it:

1 a sensor with a gravitational characteristic deviating strongly from the sinusoidal shape,

2 Deformation of the sensor under gravitational influence and

3 the block diagram of a sensor arrangement with evaluation.

1 shows a sensor according to the invention 1 , whose gravitational characteristic deviates strongly from the sinusoidal shape. The sensor 1 consists of a base plate 3 and a mass element 4 on the base plate 3 supported by a two sections 6.1 . 6.2 exhibiting support 6 is arranged, wherein the first section 6.1 of the support element 6 in the base plate 3 clamped and elastically deformable. The second section 6.2 is rigidly formed at an angle (β) with the first section 6.1 rigidly connected and carrier of the mass element 4 , The measuring point 8th is at or in the area of the mass element 4 arranged.

The angle (β) between the first and second sections 6.1 . 6.2 of the support element 6 is at an acute angle of 30 ° here.

Next it is shown that the rigid second section 6.2 of the support element 6 has a greater length than the elastic first portion 6.1 and the mass element 4 from the rigid connection between the two sections 6.1 . 6.2 removed on the second, the rigid section 6.2 is arranged, here at the end.

A dashed line becomes another mass element 5 , arranged on the elastic section 6.1 , indicated, with which longitudinal acceleration components can be suppressed in an advantageous manner.

2 shows the previously described sensor 1 under the effect of static and dynamic acceleration, which is the course of the gravitational characteristic.

• – Ein Krafteinfluss, welcher den elastisch verformbaren Abschnitt 6.1 verschiebt analog wie bei einem konventionellen Sensor, auf den eine Kraft wirkt, hier als Versatzkomponente VK bezeichnet und
• – ein Krafteinfluss, der infolge der Starrheit des starren Abschnittes 6.2 als Moment eine Biegung des elastischen Abschnittes 6.1 bewirkt, hier als Richtungskomponente RK bezeichnet.

When the sensor is bent over the rigid section 6.2 two oppositely directed forces as a result of the effective gravitational force component on the elastically deformable portion 6.1 transfer:

• - A force influence, which the elastically deformable section 6.1 shifts analogously as in a conventional sensor, acts on a force, here referred to as offset component VK and
• - A force influence, due to the rigidity of the rigid section 6.2 as a moment a bend of the elastic section 6.1 causes, here referred to as directional component RK.

Since the characteristic curve of this directional influence, the measurement deflection curve generated by it, is different from that of the sinusoidal profile of the offset component, the sum of both characteristic curves, the gravitational characteristic curve, also has a non-sinusoidal profile (lower illustration).

3 shows the block diagram of a sensor arrangement with evaluation 9 for detecting movement and gravitational acceleration.

In a measuring plane mirrored are two sensors 1 as described above and here as 1.1 and 1.2 and a conventional sensor 2 each with a base plate 3 arranged. The conventional sensor 2 consists of a base plate 3 , an elastic support element 7 with mass element 4 and a measuring point 8th , Whose gravitational characteristic has a symmetrical sinusoidal characteristic.

Upon angling of the sensor arrangement, ie a dynamic and a static movement, act on the sensors 1.1 and 1.2 the under 2 described force influences with the components offset component (VK) and direction component (RK), while on the sensor 2 only the offset component (VK) is effective.

Through the evaluation unit 9 a mathematical elimination takes place in the measuring points 8th obtained measured values for the dynamic as well as static acceleration components, such that first by pairwise mathematical linking of two sensors 1.1 / 2 and 1.2 / 2 the acceleration forces are eliminated in the longitudinal direction and then the mathematical combination of the values obtained from these pairs of acceleration, the vertical acceleration is eliminated. As an isolated variable, the gravitational acceleration (α) remains, in whose knowledge the vertical acceleration (VK) and then the longitudinal acceleration (LV) are retroactively determined.

Because of that, the two sensors 1.1 . 1.2 have a significantly different from the sinusoid gravity characteristic, a significantly higher resolution is achieved.

LIST OF REFERENCE NUMBERS

1

new sensor

2

conventional sensor

3

baseplate

4

mass element

5

mass element

6

supporting

6.1

elastically deformable section

6.2

rigid section

7

elastic support element of a conventional sensor

8th

measuring point

9

evaluation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012/013627 A1 [0004, 0006]
• DE 102014009003 A1 [0007]

Claims (9)

Sensor ( 1 ) with a base plate ( 3 ) and with a mass element ( 4 ) on the baseplate ( 3 ) by at least two sections ( 6.1 . 6.2 ) having supporting element ( 6 ), the first section ( 6.1 ) of the supporting element ( 6 ) in the base plate ( 3 ) is clamped and elastically deformable and the support element ( 6 ) a measuring point ( 8th ), characterized in that the second section ( 6.2 ) is rigidly formed at an angle (β) with the first section ( 6.1 ) is rigidly connected and carrier of the mass element ( 4 ). Sensor according to claim 1, characterized in that the angle (β) between the first and the second section (FIG. 6.1 . 6.2 ) of the supporting element ( 6 ) is an acute angle, preferably in the range 5 ≤ β ≤ 90 °. Sensor according to claim 1 or 2, characterized in that the rigid second section ( 6.2 ) of the supporting element ( 6 ) has a greater length than the elastic first section ( 6.1 ). Sensor according to one of claims 1 to 3, characterized in that the sections ( 6.1 . 6.2 ) of the supporting element ( 6 ) are in mechanical or micromechanical design rods or strips. Sensor according to one of claims 1 to 4, characterized in that the mass element ( 4 ) of the rigid connection between the two sections ( 6.1 . 6.2 ) removed on the second section ( 6.2 ), preferably at the end thereof. Sensor according to one of claims 1 to 5, characterized in that the measuring point ( 8th ) on the support element ( 6 ) is located where the deformation is most evident, such as where the mass element ( 4 ) or at one at the junction between the two sections ( 6.1 . 6.2 ) arranged further rigid strips. Sensor according to one of claims 1 to 6, characterized in that a further mass element ( 5 ) on the elastic section ( 6.1 ) is arranged. Device for detecting static and dynamic acceleration components at least comprising sensors arranged symmetrically in a measuring plane or in parallel measuring planes ( 1.1 . 1.2 ) according to one of claims 1 to 7 and a sensor ( 2 ) from a base plate ( 3 ), an elastic support element ( 7 ) with mass element ( 4 ) and a measuring point ( 8th ), Whose gravitational characteristic has a symmetrical sinusoidal characteristic, and an evaluation unit ( 9 ). Apparatus according to claim 8, characterized in that the sensor arrangement is made micromechanical, wherein the three-dimensional microstructure of the sensors ( 1.1 . 1.2 . 2 ) is formed in a wall of a carrier material and tub walls the base plate ( 3 ) or the microstructure of the sensors ( 1.1 . 1.2 . 2 ) takes place in a frame of the carrier material or in a frame for each sensor ( 1.1 . 1.2 . 2 ), wherein one or two parallel frame sides respectively the base plate ( 3 ) form.

Images