Time and/or accuracy dependent weights for network generation in a digital map
First Claim
1. A method for generating, refining and/or extending a digital map using traces derived from probe data, said digital map storing a plurality of line segments spatially associated within a coordinate system, at least one, and preferably all, of the line segments having an associated segment weight value, the method comprising a computer performing the steps of:
- providing at least one probe trace having a defined creation date;
assigning a trace weight value to the at least one probe trace;
adjusting the position of a line segment associated with the at least one probe trace based on the segment weight value of the line segment and the trace weight value;
adjusting at least one of the trace weight value and the segment weight value as a function of the time span between a recalculation date and the trace creation date, comprising;
dividing a maximal time period into a plurality of bins, each bin representing a respective portion of time between the recalculation date and the maximal time period;
assigning each bin a factor;
associating the trace with a specified one of the bins corresponding to the trace creation date; and
calculating the trace weight value as a function of the factor assigned to the bin associated with the trace;
removing a line segment from the digital map when a segment weight value of the line segment falls below a threshold.
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Accused Products
Abstract
A method for improving and extending an existing digital road network and generating new networks from statistically relevant amounts of probe data recorded by GPS-enabled navigation devices. New probe data is matched to the existing digital map, then the data merged into the existing network using a time-dependent weight and/or accuracy-dependent weight. A recalculation date is established, and the weight value of a line segment and/or trace is adjusted as a function of the time span relative to the recalculation. The function may include setting a maximal time period divided into bins each having a respective weight reduction factor, or applying decay function. Through this technique, digital maps can be updated and extended without undue influence exerted by old trace data.
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Citations
17 Claims
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1. A method for generating, refining and/or extending a digital map using traces derived from probe data, said digital map storing a plurality of line segments spatially associated within a coordinate system, at least one, and preferably all, of the line segments having an associated segment weight value, the method comprising a computer performing the steps of:
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providing at least one probe trace having a defined creation date; assigning a trace weight value to the at least one probe trace; adjusting the position of a line segment associated with the at least one probe trace based on the segment weight value of the line segment and the trace weight value; adjusting at least one of the trace weight value and the segment weight value as a function of the time span between a recalculation date and the trace creation date, comprising; dividing a maximal time period into a plurality of bins, each bin representing a respective portion of time between the recalculation date and the maximal time period; assigning each bin a factor; associating the trace with a specified one of the bins corresponding to the trace creation date; and calculating the trace weight value as a function of the factor assigned to the bin associated with the trace; removing a line segment from the digital map when a segment weight value of the line segment falls below a threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16)
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13. A method for generating, refining and/or extending a digital map using traces derived from probe data, said digital map storing a plurality of line segments spatially associated within a coordinate system, at least one, and preferably all, of the line segments having an associated segment weight value, the method comprising a computer performing the steps of:
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providing at least one probe trace having a defined creation date; assigning a trace weight value to the at least one probe trace; creating a line segment associated with the at least one probe trace; assigning a segment weight value to the line segment based on the trace weight value; adjusting at least one of the trace weight value and the segment weight value as a function of the time span between a recalculation date and the trace creation date, comprising; dividing a maximal time period into a plurality of bins, each bin representing a respective portion of time between the recalculation date and the maximal time period; assigning each bin a factor; associating the trace with a specified one of the bins corresponding to the trace creation date; calculating the trace weight value as a function of the factor assigned to the bin associated with the trace; and removing a line segment from the digital map when a segment weight value of the line segment falls below a threshold. - View Dependent Claims (14, 15, 17)
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Specification