Method For Generating a Map Depiction For Optimal Perceptibility of Streets to Travel Through

• US 20080170074A1
• Filed: 08/15/2006
• Published: 07/17/2008
• Est. Priority Date: 08/19/2005
• Status: Abandoned Application

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler AG (Mercedes-Benz Group AG)
• Inventors: Beier, Wolfgang
• Application Number:
  US12/064,189
• Publication Number:
  US 20080170074A1
• Time in Patent Office: Days
• US Class Current: 345/442
• CPC Class Codes: G01C 21/3867 Geometry of map features, e.g. shape points, polygons or for simplified maps
• CPC Class Codes: G06T 11/203 Drawing of straight lines or curves
• CPC Class Codes: G09B 29/102 using electrical means

Abstract

The invention relates to a method for generating a map depiction displaying street courses to travel through, for example in navigation, toll ticketing depiction or in precision applications such as automatic driving. For this purpose a street course consists of stringing together geometrical elements, for example, one or several circle arcs or one or several straight lines, wherein clothoids connect circle arcs and/or straight lines without sharp bends. The clothoids are calculated according to a required resolution from the arc of circle elements approximately approached by values or simply omitted, thereby making it possible to obtain a map depiction particularly reliably and optimal in terms of memory allocations.

Claims

1. A process for generating a map display with the courses of streets for use, for example, in navigation, street toll detection or in precision applications such as automatic driving, wherein a course of a street is mapped by a sequence of sequentially arranged geometric elements, wherein as geometric elements circle arcs (a, c, d, e), straight segments (b) and, for applications with higher locational resolution, clothoids are employed.

2. The process for generation of a map display according to claim 1, wherein the circle arc is described with at least three parameters, such as for example coordinates of the center point (A, B, C, D), radius (r_a, r_c, r_d, r_e,), start and end point of the circle arc, arc curve length (a, c, d, e), initial direction, magnitude of direction change (β

, X, δ

, ε

).

3. The process for generation of a map display according to claim 1, wherein a straight segment (b) is described by a particular display, for example as arc with a radius designation of “

0”

, of which the arc center point (B) is defined as the start of the straight segment.

4. The process according to claim 1, wherein clothoids are approximately reproduced via approximation shapes, for example cubic parabola.

5. The process according to claim 1, wherein for display of the course of the street clothoids are mapped as transition between sequential arcs.

6. The process according to claim 5, wherein the clothoids are computed from parameters of the circle arcs to be joined.

7. The process according to claim 5, wherein the clothoids are computed from the offset of sequential circle arcs.

8. The process according to claim 5, wherein for different offset areas or ranges, predetermined clothoids are stored as data sets and are called up for display of the course of the street.