Collaborative improvement of a vehicle's positioning

Patent metadata

Field	Value
Publication number	US-2018114441-A1
Application number	US-201715788924-A
Country	US
Kind code	A1
Filing date	Oct 20, 2017
Priority date	Oct 25, 2016
Publication date	Apr 26, 2018
Grant date	—

Abstract

The invention discloses a positioning device configured to acquire its own GNSS position, the GNSS positions of rovers in an area around the positioning device and the relative positions of the positioning device to the rovers. The positioning device is configured to calculate a best-fit position based on this data and their confidence indexes. The positioning devices may communicate directly or through a navigation assistance centre. The best-fit position may be provided with indexes of confidence, availability and integrity. In some embodiments, the positioning device of the invention may be robust enough to generate commands to the driving controls of an autonomous vehicle.

First claim

1 . A positioning device comprising:
a GNSS unit configured to acquire GNSS signals from one or more GNSS constellations and to compute a first position of the positioning device based on a PVT calculation from the GNSS signals; a position sensing unit configured to acquire relative positions from the positioning device of one or more rovers, and to determine confidence indexes of said relative positions; a communication link configured to make available to the positioning device the time-stamped GNSS PVT positions of some rovers with associated confidence indexes; and position determining logic configured to compute a second position of the positioning device based on inputs from the GNSS unit, from the position sensing unit and from the communication link, wherein said inputs are combined to determine a best fit between estimates of GNSS PVT positions and relative positions of the positioning device and the one or more rovers.

2 . The positioning device of claim 1 , wherein the position determining logic is further configured to compute the second position by calculating a best fit between a first geometry including a first group of segments connecting the first position of the positioning device and each of the GNSS PVT positions of the at least some of the rovers and a second geometry including a second group of segments connecting the first position of the positioning device and each of the relative positions of the at least some of the rovers to the positioning device.

3 . The positioning device of claim 2 , wherein the best-fit is computed by determining a best-fit segment, points of which have a minimal Euclidian distance to selected pair of points, each point in the selected pair belonging to one of the first group or the second group.

4 . The positioning device of claim 1 , wherein the position determining logic is further configured to compute the second position by calculating a confidence circle of the second position that is determined as a smallest circle including origins of selected segments connecting a candidate second position to selected points located in an intersection of one or more pairs of confidence circles, wherein a pair of confidence circles is attached to a rover and a first confidence circle in the pair relates to the rover GNSS position and the second confidence circle in the pair relates to the rover relative position to the positioning device.

5 . The positioning device of claim 1 , wherein the position determining logic is further configured to compute the second position by fracturing confidence circles around the first position of the rover and the GNSS PVT positions of the one or more rovers into a plurality of small features, pairs of a first small feature in a first confidence circle and a second small feature in a second confidence circle determining segments connecting one of the rover and one of the other rovers to another one of the rover and one of the other rovers, a best fit solution being determined by selecting a combination of rovers for which the segments best match a geometry of relative positions of the one and other rovers.

6 . The positioning device of claim 1 , wherein the position determining logic is further configured to weigh its inputs from the GNSS unit, the position sensing unit and of the communication link based on a confidence index of one or more of the rover, its GNSS position or its relative position.

7 . The positioning device of claim 1 , wherein the position determining logic is further configured to receive and process inputs from a route planning logic, said inputs being used to update the confidence index of the GNSS position and of a relative position of a rover based on a map matching algorithm.

8 . The positioning device of claim 1 , wherein the position determining logic is further configured to calculate one or more of an index of availability or an index of integrity of the second position.

9 . The positioning device of claim 1 , wherein one or more of the GNSS unit and the position determining logic are further configured to generate a first position when none is available at an epoch by propagating a last known first position, using one or more of a velocity or a direction of motion of the positioning device.

10 . The positioning device of claim 1 , wherein the position sensing unit comprises one or more position sensors with a RF transmit and/or receive (T/R) module, said T/R module configured to measure a range to another T/R module by calculating a time-of-flight between the said T/R modules and to determine an angle of the range by measuring a direction-of-flight between the said T/R modules.

11 . The positioning device of claim 10 , wherein the communication link is one or more of a vehicle-to-vehicle (V2V) communication link or a vehicle-to-infrastructure (V2I) communication link.

12 . The positioning device of claim 11 , wherein one or more of the V2V or the V2I communication links are a DSRC communication link.

13 . The positioning device of claim 12 , wherein the communication link uses a Publish/Subscribe protocol.

14 . The positioning device of claim 13 , wherein the communication link is configured to transmit and/or receive data to/from a navigation assistance centre.

15 . A positioning method comprising:
acquiring at a GNSS unit GNSS signals from one or more GNSS constellations and computing a first position of a positioning device based on a PVT calculation from the GNSS signals; acquiring at a position sensing unit relative positions to one or more rovers, and determining confidence indexes of said relative positions; acquiring at a communication link, the time-stamped GNSS PVT positions of some rovers with associated confidence indexes; and computing at a position determining logic a second position of the positioning device based on inputs from the GNSS unit, from the position sensing unit and from the communication link.

16 . A positioning system comprising:
a plurality of positioning devices on-board rovers, each positioning device comprising:
a GNSS unit configured to acquire GNSS signals from one or more GNSS constellations and to compute a first position of the positioning device based on a PVT calculation from the GNSS signals;
a position sensing unit configured to acquire relative positions from the positioning device to one or more rovers, and to determine confidence indexes of said relative positions;
a communication link configured to make available to the positioning device the time-stamped GNSS PVT positions of some rovers with associated confidence indexes; and
position determining logic configured to compute a second position of the positioning device based on inputs from the GNSS unit, from the position sensing unit and from the communication link;
wherein said inputs are combined to determine a best fit between estimates of GNSS PVT positions and relative positions of the positioning device and the one or more rovers

a navigation assistance centre comprising:
an access to a database of the plurality of rovers, drivers and positioning devices with corresponding IDs;
communication links to the plurality of positioning devices, said communication links configured to acquire at least some GNSS positions and/or relative positions of the plurality of positioning devices.

Assignees

• Centre Nat Etd Spatiales

Inventors

• Marmet François-Xavier
• Ries Lionel
• Capet Nicolas

Classifications

• G08G1/163 Primary

  involving continuous checking · CPC title

• G01C21/30

  Map- or contour-matching · CPC title

• G01S19/51 Primary

  Relative positioning · CPC title

• H04W4/046

  Electricity · mapped topic

• G01S19/48 Primary

  by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system · CPC title