Devices and methods for a rotating LIDAR platform with a shared transmit/receive path

• US 8,836,922 B1
• Filed: 08/20/2013
• Issued: 09/16/2014
• Est. Priority Date: 08/20/2013
• Status: Active Grant

• Current Assignee: Waymo LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Pennecot, Gaetan, Levandowski, Anthony, Droz, Pierre-Yves, Ulrich, Drew Eugene, Gruver, Daniel, Morriss, Zachary
• Primary Examiner(s): Alsomiri, Isam
• Assistant Examiner(s): Abraham, Samantha K
• Application Number:
  US13/971,606
• Time in Patent Office: 392 Days
• Field of Search: 356/4.01, 356/3.01, 356/4.07, 356/5.01, 356/5.09, 356/9, 356/625, 356337-342, 356/28, 356/28.5
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

A LIDAR device may transmit light pulses originating from one or more light sources and may receive reflected light pulses that are then detected by one or more detectors. The LIDAR device may include a lens that both (i) collimates the light from the one or more light sources to provide collimated light for transmission into an environment of the LIDAR device and (ii) focuses the reflected light onto the one or more detectors. The lens may define a curved focal surface in a transmit path of the light from the one or more light sources and a curved focal surface in a receive path of the one or more detectors. The one or more light sources may be arranged along the curved focal surface in the transmit path. The one or more detectors may be arranged along the curved focal surface in the receive path.

Claims

1. A light detection and ranging (LIDAR) device, comprising:

a lens mounted to a housing, wherein the housing is configured to rotate about an axis and has an interior space that includes a transmit block, a receive block, a transmit path, and a receive path, wherein the transmit block has an exit aperture in a wall that comprises a reflective surface, wherein the receive block has an entrance aperture, wherein the transmit path extends from the exit aperture to the lens, and wherein the receive path extends from the lens to the entrance aperture via the reflective surface;

a plurality of light sources in the transmit block, wherein the plurality of light sources are configured to emit a plurality of light beams through the exit aperture in a plurality of different directions, the light beams comprising light having wavelengths in a wavelength range;

a plurality of detectors in the receive block, wherein the plurality of detectors are configured to detect light having wavelengths in the wavelength range; and

wherein the lens is configured to receive the light beams via the transmit path, collimate the light beams for transmission into an environment of the LIDAR device, collect light comprising light from one or more of the collimated light beams reflected by one or more objects in the environment of the LIDAR device, and focus the collected light onto the detectors via the receive path.

2. The LIDAR device of claim 1, wherein each detector in the plurality of detectors is associated with a corresponding light source in the plurality of light sources, and wherein the lens is configured to focus onto each detector a respective portion of the collected light that comprises light from the detector'"'"'s corresponding light source.

3. The LIDAR device of claim 1, wherein the wall comprises a transparent material, the reflective surface covers a portion of the transparent material, and the exit aperture corresponds to a portion of the transparent material that is not covered by the reflective surface.

4. The LIDAR device of claim 1, wherein the transmit path at least partially overlaps the receive path.

5. The LIDAR device of claim 1, wherein the lens defines a curved focal surface in the transmit block and a curved focal surface in the receive block.

6. The LIDAR device of claim 5, wherein the light sources in the plurality of light sources are arranged in a pattern substantially corresponding to the curved focal surface in the transmit block, and wherein the detectors in the plurality of detectors are arranged in a pattern substantially corresponding to the curved focal surface in the receive block.

7. The LIDAR device of claim 1, wherein the lens has an aspheric surface and a toroidal surface.

8. The LIDAR device of claim 7, wherein the toroidal surface is in the interior space within the housing and the aspheric surface is outside of the housing.

9. The LIDAR device of claim 1, wherein the axis is substantially vertical.

10. The LIDAR device of claim 1, further comprising a mirror in the transmit block, wherein the mirror is configured to reflect the light beams toward the exit aperture.

11. The LIDAR device of claim 1, wherein the receive block comprises a sealed environment containing an inert gas.

12. The LIDAR device of claim 1, wherein the entrance aperture comprises a material that passes light having wavelengths in the wavelength range and attenuates light having other wavelengths.

13. The LIDAR device of claim 1, wherein each light source in the plurality of light sources comprises a respective laser diode.

14. The LIDAR device of claim 1, wherein each detector in the plurality of detectors comprises a respective avalanche photodiode.

15. A method comprising:

rotating a housing of a light detection and ranging (LIDAR) device about an axis, wherein the housing mounts a lens and has an interior space that includes a transmit block, a receive block, a transmit path, and a receive path, wherein the transmit block has an exit aperture in a wall that comprises a reflective surface, wherein the receive block has an entrance aperture, wherein the transmit path extends from the exit aperture to the lens, and wherein the receive path extends from the lens to the entrance aperture via the reflective surface;

emitting, by a plurality of light sources in the transmit block, a plurality of light beams through the exit aperture in a plurality of different directions, the light beams comprising light having wavelengths in a wavelength range;

receiving, by the lens, the light beams via the transmit path;

collimating, by the lens, the light beams for transmission into an environment of the LIDAR device;

collecting, by the lens, light from one or more of the collimated light beams reflected by one or more objects in the environment of the LIDAR device;

focusing, by the lens, the collected light onto a plurality of detectors in the receive block via the receive path; and

detecting, by the plurality of detectors in the receive block, light from the focused light having wavelengths in the wavelength range.

16. The method of claim 15, wherein each detector in the plurality of detectors is associated with a corresponding light source in the plurality of light sources, the method further comprising:

focusing onto each detector, by the lens, a respective portion of the collected light that comprises light from the detector'"'"'s corresponding light source.

17. The method of claim 15, further comprising:

reflecting, by a mirror in the transmit block, the emitted light beams toward the exit aperture.

18. The method of claim 15, wherein the wall comprises a transparent material, the reflective surface covers a portion of the transparent material, and the exit aperture corresponds to a portion of the transparent material that is not covered by the reflective surface.