# US 12,769,001 B1 · False-positive object identification

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- Number: US 12,769,001 B1
- Document ID: US12769001B1
- Status: Granted
- Kind: B1
- Application number: 17/876,347
- Filed: 2022-07-28
- Granted: 2026-10-20
- Earliest claimed: 2022-07-28
- Assignees: Zoox, Inc.
- Applicants: Zoox, Inc.
- Inventors: Stefano Cattani; Shreyas Sudhir Mundhra; David Pfeiffer; Jifei Qian; Arvind Srivastav
- Web page: https://patentgrep.com/patent/US12769001B1

## CPC

- G01S 17/931: of land vehicles
- G01S 7/495: Counter-measures or counter-counter-measures {using electronic or electro-optical means}
- 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

Techniques for identifying false-positives caused by sensor deflection off of reflective surfaces. The techniques may include receiving data indicating a presence of an object in an environment of a vehicle. Based at least in part on the data, a determination may be made that the object is occluded from view by another object in the environment. The techniques may also include determining that a retroreflective surface is located within a threshold proximity of the other object in the environment. Based at least in part on the retroreflective surface being located within the threshold proximity of the other object, a determination may be made that the presence of the object is caused by a false-positive condition associated with a sensor of the vehicle reflecting off of the retroreflective surface. In some instances, the object may be labeled as a false-positive object that is absent from the environment.

## Claims

### Claim 1

A system comprising:
one or more processors; and
one or more non-transitory computer-readable media storing instructions that, when executed by the one or more processors, cause the system to perform operations comprising:
receiving lidar data generated by a lidar sensor of a vehicle and associated with an environment in which the vehicle is operating, the lidar data indicating a presence of an object at a location in the environment;
determining that the location is within an occluded region of the environment that, from a perspective of the lidar sensor, is occluded from view by an intervening object located between the lidar sensor and the occluded region; determining, based at least in part on the location being within the occluded region, an existence of a geometrical relationship between the object, the intervening object, and a retroreflective surface;
determining, based at least in part on the existence of the geometrical relationship, a probability that the presence of the object is caused by a false-positive condition in which a laser emitted from the lidar sensor deflected off of the intervening object, reflected off of the retroreflective surface, deflected again off of the intervening object, and received by the lidar sensor; and
based at least in part on determining that said probability meets or exceeds a probability threshold, performing at least one of:
labeling the object in the lidar data as a false-positive object that is absent from the environment; or
precluding a bounding region associated with the object from being included in the lidar data.

### Claim 2 (depends on 1)

The system of claim 1, the operations further comprising:
determining a first size associated with the object; and
determining a difference between the first size associated with the object and a second size associated with the intervening object from the perspective of the lidar sensor;
wherein determining that the presence of the object is caused by the false-positive condition is further based at least in part on the difference between the first size and the second size.

### Claim 3 (depends on 1)

The system of claim 1, the operations further comprising:
determining a first distance between the intervening object and the retroreflective surface; and
determining a second distance between the object and the intervening object;
wherein determining the existence of the geometrical relationship between the object, the intervening object, and the retroreflective surface is further based at least in part on a difference between the first distance and the second distance being less than a threshold difference.

### Claim 4

A method comprising:
receiving sensor data from a sensor of a vehicle, the sensor data indicating a presence of an object at a location in an environment;
determining, based at least in part on the sensor data, that the location is an occluded location that is occluded from view of the sensor by an intervening object located between the sensor and the occluded location;
determining that a retroreflective surface in the environment is located within a threshold proximity of the object;
determining that an object velocity associated with the object is less than a threshold velocity; and
determining, based at least in part on the object velocity being less than the threshold velocity, the retroreflective surface being located within the threshold proximity of the object, and the occluded location being occluded from view of the sensor, that the presence of the object is caused by a false-positive condition in which a sensor beam transmitted from the sensor deflected off of the intervening object, reflected off of the retroreflective surface, deflected again off of the intervening object, and was received by the sensor.

### Claim 5 (depends on 4)

The method of claim 4, further comprising determining that a difference in size between the object and the intervening object is less than a threshold difference, wherein determining that the presence of the object is caused by the false-positive condition is further based at least in part on the difference in size being less than the threshold difference.

### Claim 6 (depends on 4)

The method of claim 4, further comprising determining the threshold proximity based at least in part on at least one of:
a first distance between the intervening object and at least one of the retroreflective surface, the vehicle, or the object; or
a second distance between the vehicle and at least one of the object, the intervening object, or the retroreflective surface.

### Claim 7 (depends on 6)

The method of claim 6, wherein determining the threshold proximity comprises determining a perimeter representing multiple locations in the environment at which objects, if located, are potential false-positive objects.

### Claim 8 (depends on 4)

The method of claim 4, wherein the sensor is a lidar sensor and the false-positive condition is caused by a laser emitted from the lidar sensor being deflected off of the intervening object and reflected back to the lidar sensor off of the retroreflective surface.

### Claim 9 (depends on 4)

The method of claim 4, wherein the sensor data is perception data that is indicative of a location in the environment of the retroreflective surface, and wherein determining that the retroreflective surface is located within the threshold proximity of the object is based at least in part on the location.

### Claim 10 (depends on 4)

The method of claim 4, further comprising determining a location of the retroreflective surface in the environment based at least in part on at least one of map data associated with the environment or the sensor data, and wherein determining that the retroreflective surface is located within the threshold proximity of the object is based at least in part on determining the location.

### Claim 11 (depends on 4)

The method of claim 4, further comprising at least one of:
labeling the object as a false-positive object that is absent from the environment; or
precluding a bounding box associated with the object from perception output data that is to be processed by another component of the vehicle.

### Claim 12 (depends on 4)

The method of claim 4, wherein the sensor data is perception data including a bounding box associated with the object, the bounding box indicating that a location of the object is within a region of the environment that is occluded by the intervening object.

### Claim 13

One or more non-transitory computer-readable media storing instructions that, when executed, cause one or more processors to perform operations comprising:
receiving sensor data from a sensor of a vehicle, the sensor data indicating a presence of an object at a location in an environment;
determining, based at least in part on the sensor data, that the location is an occluded location that is occluded from view of the sensor by an intervening object located between the sensor and the occluded location;
determining that a retroreflective surface in the environment is located within a threshold proximity of the object;
determining that a difference in size between the object and the intervening object is less than a threshold difference; and
determining, based at least in part on the difference in size being less than the threshold difference, the retroreflective surface being located within the threshold proximity of the object, and the occluded location being occluded from view of the sensor, that the presence of the object is caused by a false-positive condition in which a sensor beam transmitted from the sensor deflected off of the intervening object, reflected off of the retroreflective surface, deflected again off of the intervening object, and was received by the sensor.

### Claim 14 (depends on 13)

The one or more non-transitory computer-readable media of claim 13, the operations further comprising determining the threshold proximity based at least in part on at least one of:
a first distance between the intervening object and at least one of the retroreflective surface, the vehicle, or the object; or
a second distance between the vehicle and at least one of the object, the intervening object, or the retroreflective surface.

### Claim 15 (depends on 14)

The one or more non-transitory computer-readable media of claim 14, wherein determining the threshold proximity comprises determining a perimeter representing multiple locations in the environment at which objects, if located, are potential false-positive objects.

### Claim 16 (depends on 13)

The one or more non-transitory computer-readable media of claim 13, wherein the sensor is a lidar sensor and the false-positive condition is caused by a laser emitted from the lidar sensor being deflected off of the intervening object and reflected back to the lidar sensor off of the retroreflective surface.

### Claim 17 (depends on 13)

The one or more non-transitory computer-readable media of claim 13, wherein the sensor data is perception data that is indicative of a location in the environment of the retroreflective surface, and wherein determining that the retroreflective surface is located within the threshold proximity of the object is based at least in part on the location.