Method and device for identifying contamination on a protective screen of a lidar sensor

Patent metadata

Field	Value
Publication number	US-2023213630-A1
Application number	US-202118000988-A
Country	US
Kind code	A1
Filing date	Jun 2, 2021
Priority date	Jun 9, 2020
Publication date	Jul 6, 2023
Grant date	—

Abstract

A method and device for identifying contamination on a protective screen of a lidar sensor may involve determining a sector background noise in a particular sector of a detection region of the lidar sensor and a detection region background noise is determined in a remaining detection region or the entire detection region. Contamination in the sector in question is then determined if the sector background noise is significantly lower than the detection region background noise. Alternatively, or additionally, a sector background noise is determined in the sector in question at different sensitivities of a receiver of the lidar sensor, and contamination in the sector in question is then determined if a sector background noise determined with a higher sensitivity is not significantly higher than a sector background noise determined with a lower sensitivity.

First claim

1 - 10 . (canceled)

11 . A method for identifying contamination on a protective screen of a Lidar sensor, comprising:
dividing a detection region of the Lidar sensor into multiple sectors, wherein it is determined by sector whether there is contamination on the protective screen in the respective sector, and wherein
a sector background noise is determined in each sector and a detection region background noise is determined in the remaining detection region or the entire detection region, wherein it is inferred that there is contamination in the respective sector if the sector background noise is significantly lower than the detection region background noise, and/or
in each sector a sector background noise is determined at various sensitivities of a receiver on the Lidar sensor, wherein it is inferred that there is contamination in the respective sector if a sector background noise detected at a higher sensitivity is not significantly higher than a sector background noise detected at a lower sensitivity.

12 . The method as in claim 11 , wherein the sector background noise and the detection region background noise are determined based on a background light intensity detected for a signal transit time with at least one scan between sending out one infrared laser pulse and receiving one reflection of the infrared laser pulse.

13 . The method as in claim 12 , wherein the intensity of the background light is determined over the entire signal transit time and an effective intensity value is generated.

14 . The method as in claim 13 , wherein the detection region background noise is determined based on determining a noise level of the background light in the remaining detection region or the entire detection region.

15 . The method as in claim 13 , wherein the sector background noise is determined based on
determining a noise level of the background light for exactly one scan done in the respective sector or determining a noise level of the background light for some or all of the scans done in the respective sector.

16 . The method as in claim 13 , wherein the sector background noise is determined as follows:
all inputs received by the receiver in the respective sector are integrated, reflection inputs received by the receiver from reflections of multiple infrared laser pulses in the respective sector are integrated, and a total noise input describing the sector background noise for the respective sector is determined from the difference between the integrated received inputs and the integrated reflection inputs.

17 . The method as in claim 11 , wherein the receiver sensitivity is set based on an operating point adjustment or by changing an internal amplification factor of the speaker.

18 . A device for identifying contamination on a protective screen of a Lidar sensor, wherein
a detection region of the Lidar sensor is divided into multiple sectors and a data processing unit is configured to determine by sector whether there is contamination on the protective screen in the respective sector, wherein the data processing unit: determines a sector background noise in each sector and determines a detection region background noise in the remaining detection region or the entire detection region, and infers that there is contamination in the respective sector if the sector background noise is significantly lower than the detection region background noise, and/or in each sector determines a sector background noise at various sensitivities of a receiver of the Lidar sensor, and infers that there is contamination in the respective sector if a sector background noise detected at a higher sensitivity is not significantly higher than a sector background noise detected at a lower sensitivity.

19 . The device as in claim 18 wherein in a vehicle and/or a robot, the at least one Lidar sensor is intended for surroundings detection.

20 . The method as in claim 19 , wherein
based on data detected by the at least one Lidar sensor, an automated or autonomous vehicle and/or robot is operated and when at least one instance of contamination is detected on the protective screen of the at least one Lidar sensor, automated operation is reduced and/or at least one measure is taken to remove the at least one instance of contamination.

Assignees

• Mercedes Benz Group Ag
• Bosch Gmbh Robert

Inventors

• Schindler Philipp
• Scharf Andreas

Classifications

• G01S7/497 Primary

  Means for monitoring or calibrating · CPC title

• G01S17/931 Primary

  of land vehicles · CPC title

• G01S2007/4977

  including means to prevent or remove the obstruction · CPC title

• G01J1/4257

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title

• G01S2007/4975

  of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen · CPC title