Method for calibrating a laser scanner, and technical apparatus

Patent metadata

Field	Value
Publication number	US-12455359-B2
Application number	US-202118272398-A
Country	US
Kind code	B2
Filing date	Dec 2, 2021
Priority date	Jan 14, 2021
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

In a method for calibrating a laser scanner of a vehicle by at least one reflection unit for reflecting a laser beam of the laser scanner, the at least one reflection unit including a first plate, a second plate, and a screen, the first plate being arranged between the second plate and the screen in a beam direction, the first plate having a first reflection surface, the second plate having a second reflection surface, the screen having a third reflection surface, a gap that extends in the vertical direction and in a transverse direction being formed between the first plate and the second plate, and a projection of the gap in the beam direction being incident on the third reflection surface, an alignment of the laser scanner being checked by a laser beam of the laser scanner being directed at the at least one reflection unit and the laser beam being moved in the transverse direction along the at least one reflection unit, and, for a plurality of positions of the laser beam in the transverse direction, a respective distance of the laser scanner from that reflection surface from which the laser beam is reflected being measured, and an alignment of the laser scanner being determined from the measured distances, and the alignment of the laser scanner being corrected in the case of an incorrect alignment of the laser scanner. An apparatus, configured to perform the method, includes at least one vehicle having a laser scanner, and at least one reflection unit for reflecting a laser beam of the laser scanner.

First claim

The invention claimed is:

1. A method for calibrating a laser scanner of a vehicle by at least one reflection unit adapted to reflect a laser beam of the laser scanner, the reflection unit including a first plate, a second plate, and a screen, the first plate arranged between the second plate and the screen in a beam direction, the first plate having a first reflection surface extending at least approximately perpendicular to the beam direction, the second plate having a second reflection surface extending at least approximately perpendicular to the beam direction, the screen having a third reflection surface extending at least approximately perpendicular to the beam direction, the first plate arranged offset from the second plate in a vertical direction to form a gap that extends in the vertical direction and in a transverse direction between the first plate and the second plate, the screen being adapted and arranged so that a projection of the gap in the beam direction is incident on the third reflection surface of the screen, comprising:
checking an alignment of the laser scanner, the checking including:
directing a laser beam of the laser scanner at the reflection unit at least approximately in the beam direction;
moving the laser beam being in the transverse direction along the reflection unit;
measuring, for a plurality of positions of the laser beam in the transverse direction, a distance of the laser scanner from a respective one of the reflection surfaces from which the laser beam is reflected; and
determining an alignment of the laser scanner from the measured distances of the laser scanner from the respective one of the reflection surfaces; and

correcting the alignment of the laser scanner and/or providing an instruction for correction of the laser scanner in response to the determination of an incorrect alignment of the laser scanner;
wherein an extension of the third reflection surface of the screen in the vertical direction is greater than an extension of the gap in the vertical direction, and an extension of the third reflection surface of the screen in the transverse direction is greater than an extension of the gap in the transverse direction.

2. The method according to claim 1 , wherein the checking of the alignment of the laser scanner is repeated at defined and/or periodic time intervals, the correcting and/or providing being performed after each check in response to the determination of the incorrect alignment of the laser scanner.

3. The method according to claim 1 , wherein the correcting includes adjusting the laser scanner so that the laser beam impinges on the third reflection surface while moving in the transverse direction through the gap.

4. The method according to claim 1 , further comprising determining a slope of a surface on which the vehicle is located before the checking of the alignment of the laser scanner, the reflection unit being aligned so that the gap is at a same height in the vertical direction as the laser scanner.

5. The method according to claim 1 , further comprising visually displaying, acoustically signaling, and/or transmitting the determined alignment of the laser scanner to a central computer.

6. A method for calibrating a laser scanner of a vehicle by at least one reflection unit adapted to reflect a laser beam of the laser scanner, the reflection unit including a first plate, a second plate, and a screen, the first plate arranged between the second plate and the screen in a beam direction, the first plate having a first reflection surface extending at least approximately perpendicular to the beam direction, the second plate having a second reflection surface extending at least approximately perpendicular to the beam direction, the screen having a third reflection surface extending at least approximately perpendicular to the beam direction, the first plate arranged offset from the second plate in a vertical direction to form a gap that extends in the vertical direction and in a transverse direction between the first plate and the second plate, the screen being adapted and arranged so that a projection of the gap in the beam direction is incident on the third reflection surface of the screen, comprising:
checking an alignment of the laser scanner, the checking including:
directing a laser beam of the laser scanner at the reflection unit at least approximately in the beam direction;
moving the laser beam being in the transverse direction along the reflection unit;
measuring, for a plurality of positions of the laser beam in the transverse direction, a distance of the laser scanner from a respective one of the reflection surfaces from which the laser beam is reflected; and
determining an alignment of the laser scanner from the measured distances of the laser scanner from the respective one of the reflection surfaces; and

correcting the alignment of the laser scanner and/or providing an instruction for correction of the laser scanner in response to the determination of an incorrect alignment of the laser scanner:
wherein the at least one reflection unit includes a first reflection unit and a second reflection unit, the first reflection unit and the second reflection unit being arranged so that a vertical direction of the first reflection unit is parallel to a vertical direction of the second reflection unit, the method further comprising:
directing the laser beam of the laser scanner at the first reflection unit at least approximately in a beam direction of the first reflection unit;
moving the laser beam in a transverse direction of the first reflection unit along the first reflection unit;
for a plurality of positions of the laser beam in the transverse direction, measuring a respective distance of the laser scanner from the respective one of the reflection surfaces of the first reflection unit from which the laser beam is reflected;
directing the laser beam of the laser scanner at the second reflection unit at least approximately in a beam direction of the second reflection unit;
moving the laser beam in a transverse direction of the second reflection unit along the second reflection unit; and
for a plurality of positions of the laser beam in the transverse direction, measuring a respective distance of the laser scanner from a respective one of the reflection surfaces of the second reflection unit from which the laser beam is reflected.

7. The method according to claim 6 , wherein the first reflection unit and the second reflection unit are arranged so that the beam direction of the first reflection unit is at least approximately perpendicular to the beam direction of the second reflection unit.

8. The method according to claim 6 , wherein the first reflection unit and the second reflection unit are arranged so that the beam direction of the first reflection unit is at least approximately parallel to the transverse direction of the second reflection unit.

9. The method according to claim 6 , wherein the first reflection unit and the second reflection unit are arranged so that the gap of the first reflection unit and the gap of the second reflection unit are aligned with each other in the vertical direction.

10. A method for calibrating a laser scanner of a vehicle by at least one reflection unit adapted to reflect a laser beam of the laser scanner, the reflection unit including a first plate, a second plate, and a screen, the first plate arranged between the second plate and the screen in a beam direction, the first plate having a first reflection surface extending at least approximately perpendicular to the beam direction, the second plate having a second reflection surface extending at least approximately perpendicular to the beam direction, the screen h

Assignees

• Sew Eurodrive Gmbh & Co Kg

Inventors

• Sliskovic Maja
• Harr Valentin

Classifications

• G01S7/497

  Means for monitoring or calibrating · CPC title

• G01S7/4086

  in a calibrating environment, e.g. anechoic chamber · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G01B11/26

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G01S17/931

  of land vehicles · CPC title