Waymo patents method to detect dirt on self-driving car lidar sensors
This patent describes a way for self-driving cars to check if their lidar sensors are dirty. The system looks for unusual light patterns caused by dirt blocking the sensor and compares them to reflections from shiny objects. If the sensor is fouled, the car can trigger a cleaning system or adjust how it drives.
In the filing’s own words
An example method includes receiving point cloud information about a field of view of a lidar system. The point cloud information includes spatiotemporal and amplitude information about return light received. The method also includes determining, based on the point cloud information, a set of bright light returns from at least one highly reflective object. The bright light returns include return light having an amplitude above a photon threshold and a corresponding bright light return range. The method yet further includes determining, based on the point cloud information, a set of crosstalk returns. The crosstalk returns include return light having a corresponding crosstalk return range. The method includes adjusting, based on a normalized number of crosstalk returns, at least one of: a cleaning system, an operating mode of a lidar system, or an operating mode of a vehicle.
What exactly they claim (claim 1)
1. A light detection and ranging (lidar) system comprising: at least one light-emitter device configured to emit light pulses; at least one detector; and a controller comprising at least one processor and a memory, wherein the at least one processor executes instructions stored in the memory so as to perform operations, the operations comprising: causing the at least one light-emitter device to emit at least one light pulse; receiving, from the at least one detector, information indicative of return light; determining, based on the received information, at least one bright light return associated with at least one highly reflective object; classifying a portion of the return light as crosstalk light; and determining a normalized number of crosstalk returns based on an apparent size of the at least one highly reflective object.
Facts
- Company
- Google (Waymo LLC)
- Official title
- Methods for detecting lidar aperture fouling
- Patent number
- US12748199B2
- Application number
- 18778648
- Filed
- Jul 19, 2024
- Granted
- Sep 29, 2026
- Inventors
- 2
- Claims
- 20
Classified under
G01S 7/497 Physics & computingB60S 1/56 Operations & transportG01S 17/931 Physics & computingG01S 2007/4977 Physics & computingMore from Google in Cars & transport
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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.