Systems and methods for selecting light emitters for emitting light

Patent metadata

Field	Value
Publication number	US-11368153-B2
Application number	US-202017039940-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Nov 29, 2019
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

An example circuit includes a plurality of light emitters connected in parallel between a first node and a second node. The circuit also includes a plurality of capacitors, with each capacitor corresponding to one of the light emitters, and a plurality of discharge-control switches, with each discharge-control switches corresponding to one of the capacitors. The circuit further includes a pulse-control switch connected to the plurality of light emitters. During a first period, the pulse-control switch restricts current flow, and each of the plurality of capacitors is charged via the first node. During a second period, one or more of the plurality of discharge-control switches allows current flow that discharges one or more corresponding capacitors. During a third period, the pulse-control switch allows current flow that discharges one or more undischarged capacitors of the plurality of capacitors through one or more corresponding light emitters.

First claim

What is claimed is:

1. A method comprising:
emitting light using a plurality of light emitters during a first scan of an environment;
receiving reflected portions of the emitted light corresponding to the first scan;
identifying, based on the received reflected portions of emitted light, at least one cluster of high-intensity reflections;
determining, based on the at least one cluster of high-intensity reflections (i) a portion of the environment to illuminate using the plurality of light emitters in a second scan, wherein the portion of the environment excludes the at least one cluster of high-intensity reflections, and (ii) a remaining portion of the environment, wherein the remaining portion of the environment includes the at least one cluster of high-intensity reflections;
determining one or more light emitters, from among the plurality of light emitters, that correspond to the portion of the environment;
determining one or more light emitters, from among the plurality of light emitters, that correspond to the remaining portion of the environment;
during the second scan, emitting light from the one or more light emitters that correspond to the portion of the environment, and either:
(i) not emitting light from the one or more light emitters that correspond to the remaining portion of the environment, or
(ii) emitting light from the one or more light emitters that correspond to the remaining portion of the environment at a different power level than light emitted from the one or more light emitters that correspond to the portion of the environment.

2. The method of claim 1 , wherein emitting light from the one or more light emitters that correspond to the portion of the environment, and not emitting light from the one or more light emitters that correspond to the remaining portion of the environment comprises:
during a first period, charging each capacitor in a plurality of capacitors;
during a second period, discharging one or more capacitors corresponding to the one or more light emitters that correspond to the remaining portion of the environment, and
during a third period, discharging one or more undischarged capacitors corresponding to the one or more light emitters that correspond to the portion of the environment, thereby causing the one or more corresponding light emitters to emit respective pulses of light.

3. The method of claim 1 , further comprising:
determining not to emit light towards the remaining portion of the environment.

4. The method of claim 1 , wherein the at least one cluster of high-intensity reflections corresponds to a retroreflector.

5. The method of claim 1 , wherein the remaining portion of the environment comprises a buffer region surrounding the at least one cluster of high-intensity reflections.

6. The method of claim 1 , further comprising controlling a power level of emitting light from the one or more light emitters that correspond to the portion of the environment by controlling a charge level of one or more capacitors corresponding to the one or more light emitters that correspond to the portion of the environment.

7. The method of claim 6 , wherein controlling the power level of emitting light from the one or more light emitters that correspond to the portion of the environment comprises setting different power levels for different light pulses emitted from the one or more light emitters that correspond to the portion of the environment.

8. The method of claim 1 , wherein the method is implemented using a LIDAR device, the method further comprising:
determining an expected change in position of the LIDAR device from the first scan of the LIDAR device to the second scan,
wherein determining (i) the portion of an environment to illuminate using the plurality of light emitters in the second scan, and (ii) the remaining portion of the environment is further based on the expected change in position of the LIDAR device.

9. The method of claim 1 , wherein the method is implemented using a LIDAR device, wherein determining the portion of an environment to illuminate using the plurality of light emitters in the second scan is performed during a first pulse period of the LIDAR device, and wherein the second scan is performed during a second pulse period of the LIDAR device.

10. A computing device comprising:
one or more processors; and
a non-transitory computer readable medium having instructions stored thereon that when executed by the one or more processors cause performance of a set of functions, wherein the set of functions comprises:
emitting light using a plurality of light emitters during a first scan of an environment;
receiving reflected portions of the emitted light corresponding to the first scan;
identifying, based on the received reflected portions of emitted light, at least one cluster of high-intensity reflections;
determining, based on the at least one cluster of high-intensity reflections (i) a portion of the environment to illuminate using the plurality of light emitters in a second scan, wherein the portion of the environment excludes the at least one cluster of high-intensity reflections, and (ii) a remaining portion of the environment, wherein the remaining portion of the environment includes the at least one cluster of high-intensity reflections;
determining one or more light emitters, from among the plurality of light emitters, that correspond to the portion of the environment;
determining one or more light emitters, from among the plurality of light emitters, that correspond to the remaining portion of the environment; and
during the second scan, emitting light from the one or more light emitters that correspond to the portion of the environment, and either:
(i) not emitting light from the one or more light emitters that correspond to the remaining portion of the environment, or
(ii) emitting light from the one or more light emitters that correspond to the remaining portion of the environment at a different power level than light emitted from the one or more light emitters that correspond to the portion of the environment.

11. The computing device of claim 10 , wherein emitting light from the one or more light emitters that correspond to the portion of the environment, and not emitting light from the one or more light emitters that correspond to the remaining portion of the environment comprises:
during a first period, charging each capacitor in a plurality of capacitors;
during a second period, discharging one or more capacitors corresponding to the one or more light emitters that correspond to the remaining portion of the environment, and
during a third period, discharging one or more undischarged capacitors corresponding to the one or more light emitters that correspond to the portion of the environment, thereby causing the one or more corresponding light emitters to emit respective pulses of light.

12. The computing device of claim 10 , the set of functions further comprising:
determining not to emit light towards the remaining portion of the environment.

13. The computing device of claim 10 , wherein the at least one cluster of high-intensity reflections corresponds to a retroreflector.

14. The computing device of claim 10 , wherein the remaining portion of the environment comprises a buffer region surrounding the at least one cluster of high-intensity reflections.

15. The computing device of claim 10 , further comprising controlling a power level of emitting light from the one or more light emitters that correspond to the portion of the environment by controlling a charge level of one or more capacitors corresponding t

Assignees

• Waymo Llc

Inventors

• Droz Pierre-Yves
• Tazzoli Augusto
• Marx Michael

Classifications

• H03K17/969 Primary

  having a plurality of control members, e.g. keyboard · CPC title

• H05B47/115 Primary

  by determining the presence or movement of objects or living beings · CPC title

• H03K17/04123

  in field-effect transistor switches · CPC title

• H05B45/00

  Circuit arrangements for operating light-emitting diodes [LED] · CPC title

• Y02B20/40

  Control techniques providing energy savings, e.g. smart controller or presence detection · CPC title