Methods for autonomously navigating across uncontrolled and controlled intersections

Patent metadata

Field	Value
Publication number	US-10338591-B2
Application number	US-201715819860-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	Nov 22, 2016
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

One variation of a method for autonomously navigating along a crosswalk includes: at a first time, navigating autonomously along a sidewalk toward a crosswalk coinciding with a navigation route assigned to the autonomous vehicle; recording optical data of a scene proximal the autonomous vehicle via an optical sensor integrated into the autonomous vehicle; aligning an anteroposterior axis of the autonomous vehicle to the crosswalk detected in the optical data; identifying a pedestrian proximal the crosswalk in the optical data; in response to the pedestrian entering the crosswalk at a second time succeeding the first time, predicting right of way of the autonomous vehicle to enter the crosswalk; and, in response to predicting right of the autonomous vehicle to enter the crosswalk, autonomously navigating from the sidewalk into the crosswalk and autonomously navigating along the crosswalk to an opposing sidewalk according to the navigation route.

First claim

We claim:

1. A method for autonomously navigating along a first crosswalk at an intersection by an autonomous vehicle, wherein the method comprises:
at a first time, autonomously navigating along a first sidewalk toward the first crosswalk at the intersection, wherein the first crosswalk coincides with a navigation route assigned to the autonomous vehicle;
recording optical data of a scene proximate the autonomous vehicle via an optical sensor integrated into the autonomous vehicle;
detecting the first crosswalk in the optical data;
aligning an anteroposterior axis of the autonomous vehicle to the first crosswalk detected in the optical data;
detecting a first pedestrian proximate the intersection in the optical data;
determining that the first pedestrian has entered the first crosswalk at a second time based at least in part on the optical data, wherein the second time follows the first time;
in response to determining that the first pedestrian has entered the first crosswalk at the second time,
predicting right of way of the autonomous vehicle to enter the intersection; and

in response to predicting the right of way of the autonomous vehicle to enter the intersection,
autonomously navigating from the first sidewalk into the first crosswalk; and
autonomously navigating along the first crosswalk to a second sidewalk according to the navigation route.

2. The method of claim 1 , further comprising:
detecting an unprotected crosswalk label associated with the intersection in a navigation map; and
determining that the first crosswalk is an unprotected crosswalk based at least in part on the unprotected crosswalk label, wherein detecting the first pedestrian proximate the intersection in the optical data comprises:
detecting the first pedestrian within the first sidewalk proximate the first crosswalk in optical data recorded over a first period of time, wherein the first period of time precedes the second time,

wherein the method further comprises, prior to the second time:
in response to detecting the first pedestrian within the first sidewalk proximate the first crosswalk in the optical data recorded over the first period of time,
calculating a first confidence score for the right of way of the autonomous vehicle to enter the intersection;
determining that the first confidence score is less than a first threshold score; and
in response to determining that the first confidence score is less than the first threshold score, halting on the first sidewalk proximate the first crosswalk,

wherein predicting the right of way of the autonomous vehicle to enter the intersection comprises:
in response to determining that the first pedestrian has entered the first crosswalk at the second time,
calculating a second confidence score for the right of way of the autonomous vehicle to enter the intersection; and
determining that the second confidence score exceeds the first confidence score, and
wherein autonomously navigating from the first sidewalk into the first crosswalk comprises:
in response to determining that the second confidence score exceeds the first confidence score,
autonomously navigating from the first sidewalk into the first crosswalk.

3. The method of claim 2 , further comprising:
detecting a vehicle approaching the intersection in the optical data recorded over the first period of time;
determining a first velocity of the vehicle based at least in part on the optical data recorded over the first period of time, wherein the first confidence score is calculated as an inverse function of the first velocity of the vehicle;
determining a second velocity of the vehicle based at least in part on optical data recorded over a second period of time, wherein the second period of time follows the first period of time; and
determining that the second velocity is less than the first velocity,
wherein the second confidence score for the right of way of the autonomous vehicle is calculated based at least in part on the second velocity in response to determining that the second velocity is less than the first velocity.

4. The method of claim 2 , wherein autonomously navigating along the first crosswalk to the second sidewalk comprises:
autonomously navigating from the first sidewalk into the first crosswalk via a near ramp at the intersection, wherein the near ramp extends between at least a portion of the first sidewalk and at least a first portion of the first crosswalk;
autonomously navigating within the first crosswalk to a far ramp, wherein the far ramp extends between at least a second portion of the first crosswalk and at least a portion of the second sidewalk, and wherein autonomously navigating within the first crosswalk to the far ramp comprises autonomously maintaining at least a threshold distance between the autonomous vehicle and the first pedestrian as the first pedestrian moves through the first crosswalk; and
autonomously navigating from the first crosswalk to the second sidewalk via the far ramp.

5. The method of claim 1 , wherein detecting the first pedestrian proximate the intersection in the optical data comprises:
detecting the first pedestrian within the second sidewalk proximate the first crosswalk in optical data recorded over a first period of time preceding the second time,
wherein the method further comprises:
prior to the second time:
determining that the first pedestrian is stopped within the second sidewalk based at least in part on the optical data recorded over the first period of time preceding the second time;
in response to determining that the first pedestrian is stopped within the second sidewalk,
calculating a first confidence score for the right of way of the autonomous vehicle to enter the intersection;
determining that the first confidence score is less than a first threshold score; and
in response to determining that first confidence score is less than the first threshold score, halting on the first sidewalk proximate the first crosswalk,

wherein predicting the right of way of the autonomous vehicle to enter the intersection comprises:
in response to determining that the first pedestrian has entered the first crosswalk at the second time,
determining a speed of the first pedestrian based at least in part on the optical data;
calculating a second confidence score for the right of way of the autonomous vehicle to enter the intersection as an inverse function of a difference between the speed of the first pedestrian and a predefined nominal pedestrian speed; and
wherein autonomously navigating from the first sidewalk into the first crosswalk comprises:
in response to determining that the second confidence score exceeds the first confidence score,
autonomously navigating from the first sidewalk into the first crosswalk and past the first pedestrian.

6. The method of claim 1 , wherein detecting the first pedestrian proximate the intersection in the optical data comprises:
detecting a group of pedestrians within the first sidewalk adjacent the first crosswalk, wherein the first pedestrian is one of the group of pedestrians, wherein predicting the right of way of the autonomous vehicle to enter the intersection comprises:
determining that a subset of the group of pedestrians has entered the first crosswalk at approximately the second time based at least in part on the optical data;
determining that the subset of the group of pedestrians exceeds a threshold proportion of the group of pedestrians; and
in response to determining that the subset of the group of pedestrians exceeds the threshold proportion, predicting the right of way of the autonomous vehicle to enter the intersection, and

wherein autonomously navigating along the first crosswalk to the second sidewalk comprises:
autonomo

Assignees

• Amazon Tech Inc

Inventors

• Baalke Uriah
• Braun Stav
• Jin Sonia

Classifications

• B60W2554/00

  Input parameters relating to objects · CPC title

• G16Z99/00

  Subject matter not provided for in other main groups of this subclass · CPC title

• B60W30/0956

  the prediction being responsive to traffic or environmental parameters · CPC title

• B60W50/0097

  Predicting future conditions · CPC title

• G05D1/0276

  using signals provided by a source external to the vehicle (involving a plurality of vehicles G05D1/0287; automatically controlling vehicle speed responsive to externally generated signals B60K31/0058) · CPC title