Parking garage environment detection and ehpe determination for vehicular navigation

Patent metadata

Field	Value
Publication number	US-2015142309-A1
Application number	US-201314083707-A
Country	US
Kind code	A1
Filing date	Nov 19, 2013
Priority date	Nov 19, 2013
Publication date	May 21, 2015
Grant date	—

Abstract

Implementations of the present invention contemplate obtaining a more accurate estimated horizontal position error (EHPE) under conditions in which the telematics unit of a vehicle cannot receive GNSS signals. In particular, the invention contemplates determining that a vehicle is entering a parking garage and obtaining a more accurate estimated horizontal position error (EHPE) of the vehicle in the parking garage when GNSS signals are unavailable.

First claim

1 . A method, implemented at a telematics unit of a vehicle, for calculating the estimated horizontal position error (EHPE) of a position of a vehicle provided by a dead reckoning (DR) engine, the method comprising:
determining that the vehicle is operating within a parking garage, wherein determining that the vehicle is operating within a parking garage triggers the use of a parking garage mode by a DR engine of the telematics unit; and determining the EHPE of the vehicle according to the parking garage mode of the DR engine.

2 . The method of claim 1 , wherein determining that the vehicle is operating within a parking garage comprises analyzing data received from a GNSS.

3 . The method of claim 1 , wherein determining that the vehicle is operating within a parking garage comprises analyzing heading change characteristics of vehicular movement.

4 . The method of claim 3 , wherein analyzing heading change characteristics comprises comparing a heading change accumulation calculated at a first time with a heading change accumulation calculated at a second time.

5 . The method of claim 3 wherein analyzing heading change characteristics of vehicular movement comprises:
determining that S hd (k+L)−S hd (k)>180°, wherein S hd (k) is the heading change accumulation at time k, and S hd (k+L) is the heading change accumulation at time k+L.

6 . The method of claim 1 , wherein determining the EHPE of the vehicle according to the parking garage mode of the DR engine comprises multiplying the distance traveled by the estimated heading error (EHE).

7 . The method of claim 1 , wherein determining the EHPE of the vehicle according to the parking garage mode of the DR engine comprises:
selecting an equation to use for calculating the EHPE of the vehicle; and evaluating the selected equation; wherein selecting the equation to use for calculating the EHPE of the vehicle comprises: specifying an EHPE calculation factor relation, an EHPE calculation factor delta relation, an offset detecting threshold, an EHPE calculation limiting threshold, and an accumulated heading change consideration threshold; calculating a value for the EHPE calculation factor using the EHPE calculation factor delta relation, the offset detecting threshold, the EHPE calculation factor limiting threshold, and the accumulated heading change consideration threshold; and selecting an equation to use for calculating the EHPE of the vehicle based on the calculated value of the EHPE calculation factor.

8 . The method of claim 7 , wherein the EHPE calculation factor delta relation specifies that the EHPE calculation factor delta is equal to a first value if the accumulated heading change is less than the accumulated heading change consideration threshold and equal to a relation accounting for the accumulated heading change if the accumulated heading change is greater than the accumulated heading change consideration threshold.

9 . The method of claim 1 , wherein determining the EHPE of the vehicle according to the parking garage mode of the DR engine comprises:
determining the EHPE(k)=EHPE(k−1)+hE(k)·Δd(k) if C EHPE (N−1)≦1; and determining that

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wherein C EHPE (N)=C EHPE (N+1)+ΔC EHPE (N) when k−j=NL, C EHPE (0)=0, N is a positive integer, C EHPE(N)=T 2 if C EHPE (N)>T 2 , ΔC EHPE (N)=0if

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Assignees

• Gen Motors Llc

Inventors

• Sun Debo
• Hay Curtis L

Classifications

• G01S19/48

  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

• G01C21/12 Primary

  executed aboard the object being navigated; Dead reckoning · CPC title

• B60W10/00

  Conjoint control of vehicle sub-units of different type or different function (for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00) · CPC title

• G01C21/206 Primary

  specially adapted for indoor navigation · CPC title

• G01S19/49 Primary

  whereby the further system is an inertial position system, e.g. loosely-coupled · CPC title