Rotating compact light ranging system

Patent metadata

Field	Value
Publication number	US-11300665-B2
Application number	US-202117323983-A
Country	US
Kind code	B2
Filing date	May 18, 2021
Priority date	Dec 7, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A light ranging system including a shaft; a first circuit board assembly that includes a stator assembly comprising a plurality of stator elements arranged about the shaft on a surface of the first circuit board assembly; a second circuit board assembly rotationally coupled to the shaft, wherein the second circuit board assembly includes a rotor assembly comprising a plurality of rotor elements arranged about the shaft on a surface of the second circuit board assembly such that the plurality of rotor elements are aligned with and spaced apart from the plurality of stator elements; a stator driver circuit disposed on either the second or the first circuit board assemblies and configured to provide a drive signal to the plurality of stator elements, thereby imparting an electromagnetic force on the plurality of rotor elements to drive a rotation of the second circuit board assembly about the shaft; and a light ranging device mechanically coupled to the second circuit board assembly such that the light ranging device rotates with the second circuit board assembly.

First claim

What is claimed is:

1. A light ranging system comprising:
an enclosure having a base, a top cover and an optically transparent window disposed between the base and the top cover and extending fully around a periphery of the enclosure;
a shaft disposed within the enclosure and defining an axis of rotation;
a first circuit board assembly disposed within the enclosure along a plane perpendicular to the axis of rotation, the first circuit board assembly comprising a stator circuit board and a stator assembly comprising a plurality of stator elements coupled to the stator circuit board and arranged about the shaft;
a second circuit board assembly disposed within the enclosure and rotationally coupled to the shaft, wherein the second circuit board assembly comprises a rotor circuit board positioned in an opposing relationship with and parallel to the stator circuit board and a rotor assembly comprising a plurality of rotor elements coupled to the rotor circuit board and disposed about the shaft in an annular arrangement aligned with and spaced apart from the plurality of stator elements;
a light ranging device coupled to rotate with the second circuit board assembly within the enclosure, the light ranging device including a light source operable to transmit light pulses through the window to objects in a surrounding environment, and detector circuitry operable to detect reflected portions of the light pulses received through the window that are reflected from the objects in the surrounding environment; and
a stator driver circuit disposed within the enclosure and configured to provide a drive signal to the plurality of stator elements, thereby imparting an electromagnetic force on the plurality of rotor elements to drive a rotation of the second circuit board assembly about the shaft.

2. The light ranging system of claim 1 wherein the plurality of rotor elements are arranged in a first ring and the plurality of stator elements are arranged in a second ring concentric with the first ring.

3. The light ranging system of claim 1 wherein each rotor element in the rotor assembly is positioned between two adjacent rotor elements and has its poles arranged opposite the poles of the two adjacent rotor elements.

4. The light ranging system of claim 1 wherein each rotor element has north and south poles and the rotor assembly is a passive element in which the rotor elements are distributed across the annular arrangement with their north and south poles in an alternating pattern.

5. The light ranging system of claim 1 wherein each of the plurality of rotor elements is a separate permanent magnet.

6. The light ranging system of claim 1 wherein the plurality of rotor elements are positioned directly above the plurality of stator elements.

7. The light ranging system of claim 1 further comprising circuitry to compute ranging data based on the reflected portion of the light pulses.

8. The light ranging system of claim 1 wherein the stator driver circuit is configured to rotate the second circuit board assembly at a rate between 10 to 30 Hz.

9. The light ranging system of claim 1 wherein a number of stator elements in the plurality of stator elements is a multiple of three and the stator driver circuit is configured to provide a 3-phase alternating signal to the plurality of stator elements.

10. The light ranging system of claim 1 wherein the second circuit board assembly comprises a bearing coupled to the shaft, a bearing housing having a plurality of arms extending away from the bearing, and a second circuit board coupled to the bearing housing between the rotor circuit board and the top cover.

11. The light ranging system of claim 1 wherein the shaft is hollow and the system further comprises a communication channel that extends through the hollow shaft allowing ranging data from the light ranging device to be transmitted to processing circuitry disposed within the enclosure in a fixed relationship to the first circuit board assembly.

12. The light ranging system of claim 11 wherein the communication channel is an optical communication channel.

13. The light ranging system of claim 1 further comprising a wireless power transformer including a first annular transformer coil disposed on the stator circuit board and a second annular transformer coil disposed on the rotor circuit board in an opposing relationship with the first annular transformer coil, wherein the first transformer coil is concentric with and arranged radially outside the plurality of stator elements and the second transformer coil is concentric with and arranged radially outside the plurality of rotor elements.

14. The light ranging system of claim 1 wherein the detector circuitry comprises a plurality of pixels with each pixel in the plurality of pixels having a field of view that is non-overlapping with fields of view of all other pixels in the plurality of pixels, and wherein the light source is configured to project beams of light into the field ahead of the light ranging device according to an illumination pattern where each beam in the illumination pattern is coincident with a field of view of a different pixel in the plurality of pixels.

15. A light ranging system comprising:
an enclosure having a base, a top cover and an optically transparent window disposed between the base and the top cover and extending fully around a periphery of the enclosure;
a shaft disposed within the enclosure and mechanically attached to the base, the shaft defining an axis of rotation;
a lower circuit board assembly disposed within the enclosure and comprising: a stator circuit board disposed along a plane perpendicular to the axis of rotation and having a first aperture formed through a central portion of the stator circuit board, and a plurality of stator elements arranged annularly about the axis of rotation, each of the plurality of stator elements including a coil wound around a supporting element;
an upper circuit board assembly disposed within the enclosure between the lower circuit board assembly and the top cover and rotationally coupled to the shaft, the upper circuit board assembly comprising: a rotor circuit board disposed in an opposing relationship with the stator circuit board and having a second aperture formed through a central portion of the rotor circuit board, and a rotor component coupled to the rotor circuit board, the rotor component including an annular arrangement of magnetic poles spaced apart from the plurality of stator elements and surrounding the axis of rotation in an alternating pattern such that, at a periphery of the annular arrangement, each magnetic pole has a polarity that is opposite a polarity of its adjacent magnetic poles;
a stator driver circuit disposed within the enclosure and configured to provide a drive signal to the plurality of stator elements thereby imparting an electromagnetic force on the rotor component to drive a rotation of the rotor component and rotor circuit board about the axis of rotation defined by the shaft; and
an optical system disposed within the enclosure and coupled to rotate with the rotor circuit board, the optical system including a plurality of emitters configured to transmit light pulses through the window to objects in a surrounding environment, and a plurality of pixels configured to detect reflected portions of the light pulses received through the window that are reflected from the objects in the surrounding environment;
wherein the system computes distances to objects in the surrounding environment based on an elapsed time between emitted light pulses from the plurality of emitters and reflections of

Assignees

• Ouster Inc

Inventors

• Pacala Angus
• Frichtl Mark
• SHU Marvin
• Younge Eric

Classifications

• H02J50/10

  using inductive coupling · CPC title

• G05D1/43

  Control of position or course in two dimensions [2D] · CPC title

• G05D2111/10

  Optical signals · CPC title

• H05K5/10

  comprising several parts forming a closed casing · CPC title

• G01S17/10 Primary

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title