Force sensor and robot having force sensor

Patent metadata

Field	Value
Publication number	US-9671298-B2
Application number	US-201514640022-A
Country	US
Kind code	B2
Filing date	Mar 6, 2015
Priority date	Sep 21, 2012
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A force sensor according to embodiments includes a light-emitting unit, a pair of first light detectors, a reflector, and a first frame. The light-emitting unit emits diffuse light. The first light detectors are arranged in a first direction with the light-emitting unit interposed therebetween. The reflector is arranged to face the light-emitting unit on an optical axis of the light-emitting unit and reflects the diffuse light emitted from the light-emitting unit toward the first light detectors. The first frame is deformed in the first direction so that a reflection range of the diffuse light reflected by the reflector is displaced in the first direction.

First claim

What is claimed is:

1. A force sensor, comprising:
a light-emitting unit that emits diffuse light;
a pair of first light detectors that are arranged facing in a first direction with the light-emitting unit interposed between the first light detectors;
a reflector that is arranged to face the light-emitting unit on an optical axis of the light-emitting unit, the reflector reflecting the diffuse light emitted from the light-emitting unit toward the pair of first light detectors;
a first frame that is deformed in the first direction so that a reflection range of the diffuse light reflected by the reflector mounted on the first frame is displaced in the first direction;
a pair of second light detectors that are arranged in a second direction perpendicular to the first direction with the light-emitting unit interposed therebetween; and
a second frame that is deformed in the second direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the second direction, wherein
the first frame includes:
a first leg part that is fixed to a mounting surface on which the light-emitting unit is mounted; and
a first opposed surface that is supported by the first leg part so that the first opposed surface faces the light-emitting unit on the optical axis of the light-emitting unit, the first opposed surface having an opening provided in an area including a position intersecting with the optical axis of the light-emitting unit,

the second frame includes:
a second leg part that is connected to the first frame; and
a second opposed surface that is supported by the second leg part so that the second opposed surface faces the light-emitting unit on the optical axis of the light-emitting unit, the opening of the first opposed surface being located between the second opposed surface and the light-emitting unit, and

the reflector is provided, on the second opposed surface, in the area including the position intersecting with the optical axis of the light-emitting unit.

2. The force sensor according to claim 1 , wherein
the first leg part includes two legs,
the second leg part includes two legs,
the two legs of the first leg part of the first frame are provided on both sides of the first opposed surface in the first direction,
the first frame further includes connecting arms that are provided on both sides of the first opposed surface in the second direction,
the two legs of the second leg part of the second frame are provided on both sides of the second opposed surface in the second direction, and
the two legs of the second leg part are respectively connected to the connecting arms of the first frame on sides closer to the mounting surface of the light-emitting unit than to the first opposed surface.

3. The force sensor according to claim 1 , wherein
the first frame includes a connecting portion at which the first leg part and the first opposed surface are connected at an angle other than a right angle, and
the connecting portion is deformed in the first direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the first direction.

4. The force sensor according to claim 2 , wherein
the first frame includes connecting portions at which the two legs of the first leg part and the first opposed surface are respectively connected at an angle other than a right angle, and
the connecting portions are deformed in the first direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the first direction.

5. The force sensor according to claim 1 , wherein
the second frame includes a connecting portion at which the second leg part and the second opposed surface are connected at an angle other than a right angle, and
the connecting portion is deformed in the second direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the second direction.

6. The force sensor according to claim 2 , wherein
the second frame includes connecting portions at which the two legs of the second leg part and the second opposed surface are respectively connected at an angle other than a right angle, and
the connecting portions are deformed in the second direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the second direction.

7. The force sensor according to claim 3 , wherein
the second frame includes a connecting portion at which the second leg part and the second opposed surface are connected at an angle other than the right angle, and
the connecting portion is deformed in the second direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the second direction.

8. A force sensor, comprising:
a light-emitting unit that emits diffuse light;
a pair of first light detectors that are arranged facing in a first direction with the light-emitting unit interposed between the first light detectors;
a first frame that includes an opposed surface facing the light-emitting unit on an optical axis of the light-emitting unit and is fixed to a mounting surface on which the light-emitting unit is mounted, the first frame having one degree of freedom in an arrangement direction of the pair of light-emitting units;
a reflector that is provided on the opposed surface of the first frame, the reflector reflecting the diffuse light emitted from the light-emitting unit toward the pair of light-emitting units;
a pair of second light detectors that are arranged in a second direction perpendicular to the first direction with the light-emitting unit interposed therebetween; and
a second frame that is deformed in the second direction so that the reflection range of the diffuse light reflected by the reflector is displaced in the second direction, wherein
the first frame includes:
a first leg part that is fixed to a mounting surface on which the light-emitting unit is mounted; and
a first opposed surface that is supported by the first leg part so that the first opposed surface faces the light-emitting unit on the optical axis of the light-emitting unit, the first opposed surface having an opening provided in an area including a position intersecting with the optical axis of the light-emitting unit,

the second frame includes:
a second leg part that is connected to the first frame; and
a second opposed surface that is supported by the second leg part so that the second opposed surface faces the light-emitting unit on the optical axis of the light-emitting unit, the opening of the first opposed surface being located between the second opposed surface and the light-emitting unit, and

the reflector is provided, on the second opposed surface, in the area including the position intersecting with the optical axis of the light-emitting unit.

9. A force sensor, comprising:
a light-emitting unit that emits diffuse light;
a pair of first light detectors that are arranged facing in a first direction with the light-emitting unit interposed between the first light detectors;
a reflector that is arranged to face the light-emitting unit on an optical axis of the light-emitting unit, the reflector reflecting the diffuse light emitted from the light-emitting unit toward the pair of first light detectors;
a first frame that includes an opposed surface provided to face the light-emitting unit on the optical axis of the light-emitting unit and is fixed to a mounting surface on which the light-emitting unit is mounted, the first frame being deformed in the first direction so that a reflection range of the diffuse light reflected by the reflector is displaced in the first direction;
a pair of second light detectors

Assignees

• Yaskawa Electric Corp
• Univ Kyushu Nat Univ Corp

Inventors

• Sawada Renshi
• Takeshita Toshihiro
• Iwasaki Takuma
• Arinaga Yuji

Classifications

• A61B5/445

  Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore · CPC title

• G01L1/241 Primary

  by photoelastic stress analysis · CPC title

• G01B11/16

  for measuring the deformation in a solid, e.g. optical strain gauge · CPC title

• G01L5/0047

  measuring forces due to residual stresses · CPC title

• B25J9/1697

  Vision controlled systems · CPC title