Sensor arrangement for force or torque measurement, and a method for the production thereof

Patent metadata

Field	Value
Publication number	US-11433550-B2
Application number	US-201716484227-A
Country	US
Kind code	B2
Filing date	Dec 18, 2017
Priority date	Feb 7, 2017
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A sensor arrangement for measuring at least one component of a force or a torque includes a sensor assembly having a first contact structure and a second contact structure, between which the at least one component of the force or torque is to be measured, and a plurality of sensor elements. The plurality of sensor elements are each connected by way of a first joint to the first contact structure and by way of a second joint to the second contact structure and configured to measure the component of force or torque between the first contact structure and the second contact structure. The first contact structure, the second contact structure and the plurality of sensor elements form a rolled-up structure that extends like a jacket along a surface of the sensor arrangement.

First claim

The invention claimed is:

1. A sensor arrangement for measuring at least one component of a force or a torque, the sensor arrangement comprising:
a first contact structure and a second contact structure between which the at least one component of the force or torque is to be measured; and
a plurality of sensor elements, each of the plurality of sensor elements is connected by way of a respective first joint to the first contact structure and by way of a respective second joint to the second contact structure, and each of the plurality of sensor elements are configured to measure the component of the force or the torque between the first contact structure and the second contact structure,
wherein the first contact structure, the second contact structure, and the plurality of sensor elements form a rolled-up sensor structure that extends in a jacket-like or spiral-like manner along a surface of the sensor arrangement, and
wherein a circumference of the rolled-up sensor structure has an axial seam at which axial sides of the rolled-up sensor structure contact each other or at which there is a gap between the axial sides, wherein the gap is open or the gap is closed by adhesive or solder.

2. The sensor arrangement of claim 1 , wherein the plurality of sensor elements comprise three sensor elements defining a tripod structure, or six sensor elements defining a hexagonal structure, the plurality of sensor elements being inclined relative to the first contact structure and the second contact structure in order to thereby independently measure three different force components and/or three different torque components.

3. The sensor arrangement of claim 1 , wherein the plurality of sensor elements each comprise a bridge structure having a thinned portion and at least one strain gauge on the thinned portion to measure a strain on the thinned portion as a result of an application of the force or torque on the sensor arrangement.

4. The sensor arrangement of claim 3 , wherein
the bridge structure has a U-shaped cross-sectional profile with two opposite sections between which a recess is formed, the two opposite sections are bridged with a connecting section as a thinned section, and
the first contact structure and the second contact structure couple at the two opposite sections, and the strain gauge is formed on the connecting section such that the component of the force or the torque applies a lever force to the connecting section and leads to an increase in strain.

5. The sensor arrangement of claim 1 , wherein the first joint and the second joint are both flexure joints having a reduced, square or round, cross-sectional area.

6. The sensor arrangement of claim 1 , further comprising:
a first lid and a second lid, wherein the first lid is attached to the first contact structure and the second lid is attached to the second contact structure, and the first and second contact structure include means for force input or force output.

7. The sensor arrangement of claim 6 , wherein
the sensor arrangement is useable for power transmission to a tool,
the first lid and the second lid define an axial axis about which the jacket-shaped sensor structure is disposed, and the first lid and the second lid each have an opening through which the axial axis passes, and
the rolled-up sensor structure defines an interior space for permitting routing through the sensor arrangement of optical and/or electrical leads and/or elements for operating the tool along the axial axis.

8. The sensor arrangement of claim 7 , wherein
the first contact structure and the second contact structure each comprise a plurality of segments,
a sensor element is formed between two respective segments of the plurality of segments to form a plurality of sensor sections, each of the plurality of sensor segments comprising a pin extending away from the sensor module, and
the first lid and the second lid each have a plurality of grooves disposed such that the pins of the first and second contact structures are insertable into the grooves.

9. The sensor arrangement of claim 8 , further comprising:
additional sensor elements on the segments of the first contact structure or on the segments of the second contact structure,
wherein, in each case, a sensor element is connected to one of the additional sensor elements to form a half-bridge circuit.

10. The sensor arrangement of claim 1 , wherein
the first contact structure comprises a first comb structure and the second contact structure comprises a second comb structure for establishing a firm connection between the first contact structure and the second contact structure by way of an enlarged adhesion surface, and
the firm connection comprises at least one of the following connections an adhesive bond, a solder joint, and a welded joint.

11. A method for producing a sensor for measuring at least one force and one torque, the method comprising:
providing a planar sensor structure having a first contact structure and a second contact structure with a plurality of sensor elements connected in a joint-like manner therebetween; and
rolling up the planar sensor structure such that the first contact structure and the second contact structure and the plurality of sensor elements extend in the form of a jacket around an axial axis.

12. The method of claim 11 , wherein the provision of the planar sensor structure comprises:
providing a flexible body;
structuring the flexible body to form the first contact structure and the second contact structure interconnected by bridge elements; and
forming at least one respective strain gauge on the bridge elements.

13. The method of claim 11 , wherein rolling up the planar sensor structure further comprises:
inserting the planar sensor structure into a rolling device comprising a guide and an angled section, the guide being adapted to receive the planar sensor structure; and
moving the planar sensor structure toward the angled section so that the planar sensor structure is bent in sections to produce the jacket-shaped structure.

14. The method of claim 11 , further comprising:
placing a first lid and a second lid on opposite sides of the rolled-up sensor structure;
inserting the rolled-up sensor structure in a cylinder or prism-shaped mounting aid; and
applying a pressure to the first and second lids to align the jacket-shaped sensor structure with axial symmetry.

Assignees

• Univ Darmstadt Tech
• Wittenstein Se

Inventors

• Matich Sebastian
• Albrecht Walter

Classifications

• G01L1/2206

  Special supports with preselected places to mount the resistance strain gauges; Mounting of supports · CPC title

• B25J13/085 Primary

  Force or torque sensors (B25J13/082, B25J13/084 take precedence) · CPC title

• G01L5/1627

  of strain gauges (using piezoresistors G01L5/162) · CPC title

• B25J19/028

  Piezoresistive or piezoelectric sensing devices · CPC title

• A61B2090/066

  for measuring torque · CPC title