Optical spread spectrum detection and ranging

Patent metadata

Field	Value
Publication number	US-10071733-B2
Application number	US-201715403745-A
Country	US
Kind code	B2
Filing date	Jan 11, 2017
Priority date	Mar 5, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

Example implementations may relate to an obstacle detection system. In particular, an example device may include a light emitter, a line-image sensor, and a controller that are mounted on a rotatable component. In an example embodiment, the line-image sensor may receive light signals emitted from the light emitter. The controller may be communicatively coupled to the light emitter and line-image sensor and configured to determine a multipath signal based on the time of flight of the light signal and the position along the line-image sensor at which the line-image sensor received the given reflected light signal.

First claim

We claim:

1. A system comprising:
a light emitter configured to emit a light signal;
a line-image sensor configured to receive reflected light signals at a plurality of positions along the line-image sensor; and
a controller communicatively coupled to the light emitter and the line-image sensor, the controller being configured to determine whether a given reflected light signal received at the line-image sensor is a multi-path signal based on (i) an amount of time between emission of the light signal from the light emitter and reception at the line-image sensor of the given reflected light signal, and (ii) a position along the line-image sensor at which the line-image sensor received the given reflected light signal.

2. The system of claim 1 , wherein the controller is configured to determine that the given reflected light signal is a multi-path signal by:
determining the amount of time between emission of the given light signal from the light emitter and reception at the line-image sensor of the given reflected light signal;
based on the determined amount of time, identifying a target window of positions along the line-image sensor; and
determining that the line-image sensor received the given reflected light signal at a position outside of the target window of positions.

3. The system of claim 1 , wherein the controller is configured to determine that the given reflected light signal is a multi-path signal by:
determining the position along the line-image sensor at which the line-image sensor received the given reflected light signal;
based on the determined position, calculating a target window of time subsequent to emission of the light signal; and
determining that the line-image sensor received the given reflected light signal at a time outside of the target window of time.

4. The system of claim 3 ,
wherein the line-image sensor has a proximate end and a distal end, the light emitter being positioned nearer to the proximate end than the distal end, and
wherein the target window of time is a length of time subsequent to emission of the light signal, the length of time being proportionate to a distance from the proximate end of the line-image sensor to the determined position along the line-image sensor at which the line-image sensor received the given reflected light signal.

5. A method comprising:
emitting a light signal from a light emitter;
receiving a reflection of the emitted light signal, wherein the reflection of the emitted light signal is received at a position along a line-image sensor; and
determining whether the reflection of the emitted light signal received at the line-image sensor is a multi-path signal based on (i) an amount of time between emission of the light signal and reception at the line-image sensor of the reflection of the emitted light signal, and (ii) the position along the line-image sensor at which the line-image sensor received the reflection of the emitted light signal.

6. The method of claim 5 , wherein the light signal comprises a plurality of light signals that reflect off of an obstacle and return to the line-image sensor as reflected light signals; and further comprising:
estimating a distance from the line-image sensor to the obstacle based on a set of reflected light signals, wherein signals determined to be multi path signals are excluded from the set.

7. The method of claim 6 , further comprising:
rotating the light emitter.

8. A collision avoidance system, comprising:
an inertial measurement unit configured to measure rotation and acceleration of a vehicle about one or more axes of the vehicle;
an obstacle detection unit comprising:
a light emitter configured to emit a light signal;
a line-image sensor configured to receive reflected light signals at a plurality of positions along the line-image sensor; and
a controller communicatively coupled to the light emitter and the line-image sensor, the controller being configured to determine whether a given reflected light signal received at the line-image sensor is a multi-path signal based on (i) an amount of time between emission of the light signal from the light emitter and reception at the line-image sensor of the given reflected light signal, and (ii) a position along the line-image sensor at which the line-image sensor received the given reflected light signal; and

a control system, wherein the control system is communicatively coupled with the inertial measurement unit and the obstacle detection unit, and wherein the control system is configured to control the vehicle to avoid detected objects by sending control outputs to the vehicle based on information received from the inertial measurement unit and the obstacle detection unit.

Assignees

• Horizon Hobby Llc

Inventors

• Beard Paul
• Walker Jeffrey

Classifications

• G01S17/48

  Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G01S7/4876

  by removing unwanted signals (G01S7/495 takes precedence) · CPC title

• G01S7/4817

  relating to scanning · CPC title

• B60W2420/00

  Indexing codes relating to the type of sensors based on the principle of their operation · CPC title