# US 2021/0239794 A1 · Radar sensor and robot using the same

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- Number: US 2021/0239794 A1
- Document ID: US20210239794A1
- Status: Published application
- Kind: A1
- Application number: 17/238,231
- Filed: 2021-04-23
- Published: 2021-08-05
- Earliest claimed: 2018-10-24
- Assignees: ABB Schweiz AG
- Applicants: ABB Schweiz AG
- Inventors: Mathias Fauth
- Web page: https://patentgrep.com/patent/US20210239794A1

## CPC

- G01S 7/40: Means for monitoring or calibrating
- G01S 7/4017: {of HF systems}
- G01S 7/4078: {involving an integrated reference reflector or reference transponder}
- G01S 13/75: using transponders powered from received waves, e.g. using passive transponders {, or using passive reflectors}
- G01S 13/881: {for robotics}
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

A radar sensor includes: a transceiver unit for emitting a radar beam along a beam path in an outgoing direction and receiving radar radiation along the beam path in an incoming direction; and a reference object placed in the beam path to redirect part of the outgoing radar beam in the incoming direction. The reference object is one of a plurality of reference objects placed in the radar beam. A size of the reference objects in at least one dimension is smaller than a wavelength of the radar beam.

## Claims

### Claim 1

A radar sensor, comprising:
a transceiver unit configured to emit a radar beam along a beam path in an outgoing direction and to receive radar radiation along the beam path in an incoming direction; and
a reference object placed in the beam path configured to redirect part of the outgoing radar beam in the incoming direction,
wherein the reference object is one of a plurality of reference objects placed in the radar beam, and
wherein a size of the reference objects in at least one dimension is smaller than a wavelength of the radar beam.

### Claim 2 (depends on 1)

The radar sensor of claim 1, wherein at least some of the plurality of reference objects are located beyond a leakage range of the transceiver unit.

### Claim 3 (depends on 1)

The radar sensor of claim 1, wherein a size of the reference object in a first dimension is smaller than half the wavelength.

### Claim 4 (depends on 1)

The radar sensor of claim 1, wherein the at least one reference object is stationarily mounted with respect to the transceiver unit.

### Claim 5 (depends on 3)

The radar sensor of claim 3, wherein a size of the at least one reference object in a second dimension orthogonal to the first dimension is larger than the wavelength of the radar beam.

### Claim 6 (depends on 1)

The radar sensor of claim 1, wherein the reference objects comprise metallic wires.

### Claim 7 (depends on 1)

The radar sensor of claim 1, wherein each reference object is linear and has first and second ends, and
wherein the first and second ends of the reference objects are mounted in a frame.

### Claim 8 (depends on 1)

The radar sensor of claim 1, wherein at least some reference objects of the plurality of reference objects are distributed over a cross section of the radar beam.

### Claim 9 (depends on 7)

The radar sensor of claim 7, wherein the at least some reference objects are arranged in at least one plane that intersects the radar beam.

### Claim 10 (depends on 7)

The radar sensor of claim 7, wherein the at least some reference objects are arranged in at least one regular pattern.

### Claim 11 (depends on 7)

The radar sensor of claim 7, wherein the at least some reference objects are arranged in first and second regular patterns, the first pattern extending in a first plane that intersects the beam, and the second pattern extending in a second plane parallel to the first plane, and
wherein the transceiver unit is selectively operable at at least a first and a second frequency, and a distance between the two patterns equals half a Talbot distance at the first frequency.

### Claim 12 (depends on 10)

The radar sensor of claim 10, wherein, when the transceiver unit is operated at the first frequency, the reference objects of the second regular pattern are located in dark zones of a Talbot grid generated by the first regular pattern.

### Claim 13 (depends on 10)

The radar sensor of claim 10, wherein the first regular pattern is located in a leakage zone of the transceiver unit.

### Claim 14 (depends on 1)

A robot, comprising:
at least one link which is rotatably connected to a base, to an end effector, or to another link,
wherein the at least one link is provided with at least one radar sensor of claim 1.

### Claim 15 (depends on 3)

The radar sensor of claim 3, wherein the size of the reference object in the first dimension is smaller than a fifth of the wave length.

### Claim 16 (depends on 15)

The radar sensor of claim 15, wherein the size of the reference object in the first dimension is smaller than a tenth of the wavelength.

### Claim 17 (depends on 5)

The radar sensor of claim 5, wherein the size of the at least one reference object in the second dimension is larger than a diameter of the radar beam.