DE102005040032B4 - Two-axis torque sensor - Google Patents

Abstract

biaxial Moment sensor, comprising a plate-shaped, approximately rectangular receiving part with a connection for torque introduction and a connection for torque output, with appropriately aligned strain gauges (4.1 to 4.4) on the approximately rectangular flat surfaces the top and / or the bottom of the receiving part so applied are that by subtraction of by means of strain gauges (4.1 to 4.4) received two moments in the two to each other vertical axes (A1, A2) can be determined, characterized in that the receiving part (1 ') approximately cuboid is and the connection to the force / torque introduction by means of parallel to the long sides of the cuboid Receiving part (1 ') extending torsionally rigid, with one end takes place at the receiving part (1 ') attached to connecting tabs (16).

Description

The The invention relates to a biaxial moment sensor comprising a plate-shaped, approximately rectangular receiving part with a connection for torque introduction As well as a connection for torque extraction, with appropriately aligned Strain gauges on the approximately rectangular flat surfaces the top and / or the bottom of the receiving part so applied are that by subtraction of by means of strain gauges obtained measured values two moments in the two mutually perpendicular axes can be determined.

Further gives the invention uses of such a moment sensor.

One such sensor is made of "A tactile sensor based on thin-plate deformation "by Ellis, R.E., Ganeshan, S.R., & Lederman, S. J. in Robotica, 12, 343-351 (1994).

Furthermore, for example, sensors in the form of bending beams in different mounting position are common, which with strain gauges 5.1 . 5.2 are provided, as in 1 is shown schematically. Such bending beams generally have a rectangular cross-section and the strain gauges 5.1 such as 5.2 are applied to orthogonally aligned surfaces so as to measure moments perpendicular to the longitudinal major axis of the bending beam 5 lie. Although such a bending beam can also be made very slim, it still requires a relatively large installation length.

In 2 is another common embodiment of a sensor in the form of a cross 6 reproduced, with which moments can be measured, which lie in the plane in which the cross lies, on whose arms strain gauges 6.1 to 6.4 are applied. Although the cross shape can be made very short, a connection must be made in the middle of the cross, which in turn affects the mounting dimensions in a negative way.

The known embodiments Two-axis torque sensors therefore always require one relatively large installation length or length, the for example, in a finger of an artificial hand by no means to disposal stands.

There the space for example, are very cramped in fingers of an artificial hand, The invention is based on the object, a two-axis torque sensor preferably to create a small design. According to the invention this task is with a biaxial moment sensor after the The preamble of claim 1 by the features in the characterizing Part solved. advantageous Further developments are the subject of directly or indirectly refer back to claim 1 Claims. Furthermore, uses are possible specified such a small-volume torque sensor.

According to one preferred embodiment of Invention, a biaxial torque sensor has an approximately cuboid receiving part on, in which the connection to the force / torque introduction by means of parallel to the long sides of the cuboid Receiving part running torsionally stiff, with one end the receiving part connected tethers takes place.

Further can increase the sensitivity along the long sides of the rectangle and thus in the middle of at least one of the axes parallel to one of the axles. to the bottom of the cuboid Receiving part through recess and / or perpendicular thereto parallel to the short sides of the rectangle and thus parallel to the other axis centered at least one further continuous recess be educated. Here you can the continuous recesses in plan view an axisymmetric elliptical, oval, circular or rectangular or any other axisymmetric shape and combinations of these forms.

Of the small volume according to the invention biaxial torque sensor can advantageously at a Robot multi-finger hand, in fingers of an artificial robot hand as well generally used in handling technology.

According to the invention Thus, a small-volume two-axis torque sensor is created, the in installation spaces, in their length severely limited are, can be accommodated; the same applies if the width or the depth of the available Installation space is very low. The small-volume moment sensor according to the invention can be in length and / or in width certainly with dimensions of the order of magnitude from 12 to 20 mm at a thickness of the order of 1 to 3 mm become.

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

1 in perspective view of a conventional sensor in the form of a bending beam;

2 another conventional sensor in the form of a cross, also in perspective view;

3 a schematic representation of an embodiment of a biaxial torque sensor according to the invention;

4 in perspective view of an advantageous embodiment of the biaxial torque sensor according to 3 ;

5 again in perspective, a development of the embodiment of 3 and 4 with regard to the initiation of a moment;

6 a schematic representation of a bending of a receiving part and

7 a schematic representation of a rotation of the receiving part.

3 shows a schematic side view of a cuboid receiving part 1 a biaxial moment sensor, in which the binding sites 2 for torque introduction and the connection points 3 for torque discharge in a dashed line indicated sensor level SE lie.

In a perspective view of 4 an approximately cuboid receiving part 1 a biaxial moment sensor are both on its top 10 as well as on its underside 11 Strain gauges 4.1 to 4.4 Applied parallel to an axis A2, with the on the bottom 11 applied strain gauges 4.3 and 4.4 are indicated by short dashed lines.

The strain gauges 4.1 to 4.4 can also only on the top 10 or the bottom 11 be applied parallel or at an acute angle to the axis A2 of the receiving part. At the one end face 17 are the attachment sites 2 for a torque introduction and at the opposite second end face 18 are the attachment sites 3 indicated for a torque output.

To improve the sensitivity of the biaxial torque sensor is parallel to the long rectangular sides of the receiving part 1 or one axis A2 centered one from the top 10 to the bottom 11 of the cuboid receiving part 1 through recess 14 educated. In addition or instead, one can also be parallel to the shorter rectangle sides 13 or the axis A1 perpendicular to the axis A1 and thus perpendicular to the recess 14 in the middle of another continuous recess 15 be educated.

In a preferred embodiment of the invention are in 5 for cases in which the installation space is particularly cramped in length, torsionally rigid tie-down straps for force removal 16 intended. Although the connecting straps 16 moments can bend or bend outside of the sensor measuring body, moments are only there in the receiving part 1 initiated, where the connection tabs are connected by material to the receiving part.

Also in this embodiment are again aligned accordingly, for example on the top or the bottom of the receiving part 1' applied strain gauges 4.1 to 4.4 applied. The torque is diverted via the binding sites 3 , Also in this embodiment, the moments to be measured are again in contrast to 1 in 5 unregistered measurement level.

Since, as detailed above, in the inventive two-axis torque sensor in the form of a cuboid receiving part 1 respectively. 1' the attachment sites 2 for the torque introduction and the connection points 3 for the torque discharge in a plane, namely the sensor plane SE, in particular the overall length of this biaxial torque sensor can be minimized very much.

• • Eine Verbiegung des Sensorkörpers zwischen den Anbindestellen um die Achse A1 wird, wie in 6 schematisch durch einen gestrichelt wiedergegebenen Aufnahmeteil angedeutet ist, mittels der Dehnungsmessstreifen 4.3 und 4.4 gemessen, welche gleichsinnig belastet sind.
• • Eine Verdrehung (Torsion) des Sensorkörpers zwischen den Anbindestellen um die Achse A2, wie in 7 schematisch durch einen gestrichelten Aufnahmeteil 1 angedeutet wird, wird mittels Dehnungsmessstreifen 4.3 und 4.4 gemessen, welche jedoch gegensinnig belastet sind. Diese Belastung kann jedoch auch über Schubspannungs-Dehnungsmessstreifen 4.1 gemessen werden, die unter einem spitzen Winkel von beispielsweise 45° bezüglich der Achse A2 aufgebracht sind.

The measurement of moments lying in the sensor plane by means of the biaxial torque sensor according to the invention is achieved as follows:

• • A bending of the sensor body between the attachment points around the axis A1 becomes, as in 6 is indicated schematically by a dashed reproduced receiving part, by means of the strain gauges 4.3 and 4.4 measured, which are charged in the same direction.
• • A torsion of the sensor body between the attachment points around the axis A2, as in 7 schematically by a dashed receiving part 1 is indicated is by means of strain gauges 4.3 and 4.4 measured, but which are charged in opposite directions. However, this load can also shear stress strain gauges 4.1 are measured, which are applied at an acute angle, for example, 45 ° with respect to the axis A2.

1, 1'

cuboid receiving part

10

Top of 1

11

Bottom of 1

12

Long rectangular sides

13

shorter rectangle sides

14

15 recesses

16

Anbindelaschen

17 18

faces

2, 3

attachment sites

4.1 to 4.5

Strain gauges

5

bending beam

5.1 5.2

Strain gauges

6

sensor in the form of a cross

6.1 to 6.4

Strain gauges

A1, A2

axes

Claims (6)

Two-axis torque sensor, comprising a plate-shaped, approximately rectangular receiving part with a connection for torque introduction and a connection for torque output, with appropriately aligned strain gauges ( 4.1 to 4.4 ) are applied to the approximately rectangular flat surfaces on the top and / or the underside of the receiving part so that by subtraction of means of the strain gauges ( 4.1 to 4.4 ) measured values two moments in the two mutually perpendicular axes (A1, A2) can be determined, characterized in that the receiving part ( 1' ) is approximately cuboidal and the connection to the force / moment introduction by means of parallel to the longitudinal sides of the cuboid receiving part ( 1' ) running torsionally rigid, with one end to the receiving part ( 1' ) tethered connection tabs ( 16 ) he follows. Two-axis torque sensor according to claim 1, characterized in that along the long sides of the rectangle at least one center from the top to the bottom of the cuboid receiving part ( 1' ) through recess and / or perpendicular to this parallel to the shorter sides of the rectangle centered at least one through recess is formed. Two-axis torque sensor according to claim 2, characterized characterized in that the continuous recesses in plan view an axisymmetric elliptical, oval, circular or rectangular and any other axisymmetric Form and combinations of these forms. Using a biaxial torque sensor after the claims 1 to 3 in a robotic multi-finger hand. Using a biaxial torque sensor after Claim 4 in fingers of a robot hand. Using a biaxial torque sensor after the claims 1 to 3 in handling technology.