Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment
Reexamination Certificate
1999-08-13
2002-05-07
Nguyen, Tan (Department: 3661)
Data processing: vehicles, navigation, and relative location
Navigation
Employing position determining equipment
C701S117000, C340S995190, C340S905000
Reexamination Certificate
active
06385539
ABSTRACT:
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a method and system for autonomously developing geospatially specific knowledge and, more particularly, to developing or augmenting a geographic information system database by utilizing indiscriminately gathered actual probe data.
With the advance of information technologies, in particular computer processing, communications and global positioning, systems and processes have been developed to utilize these technologies to provide useful information. For example, satellite based positioning systems, such as the U.S. Global Positioning System (GPS) and the Russian Global Navigation Satellite System (GLONASS) provide position information used in vehicle and personal navigation, such as for aircraft, marine-based vehicles, land-based vehicles, as well as an individual's own use. The GPS and GLONASS systems provide an absolute position anywhere on the earth where at least four satellites can be clearly observed. Using known differential techniques, a positional accuracy of one meter or less can often be obtained.
It is also known to use fleets of probe vehicles, such as cars and trucks, equipped with differential GPS (DGPS) receivers to provide raw data along particular routes in order to monitor traffic flow. Such a system is described in U.S. Pat. No. 5,539,645, wherein a central computer receives collected and reported baseline data from probe vehicles concerning time varying quantities along selected routes. This “raw” calibration data is modeled to determine normal traffic speeds and patterns, which are compared with monitored data. Deviations outside acceptable variations are reported to the central processor, which can then determine variously occurring traffic events. This reference describes a desirable position information accuracy of, for example, 0.5 meters, in order to distinguish lane changes and particular lanes of a multi-lane roadway being travelled. While such a known DGPS receiver may have the requisite accuracy to locate a vehicle within a particular lane, it has not previously been possible to reliably determine the lane locations themselves.
German Patent documents DE 195 25 291 and DE 196 50 844 describe methods for analyzing information received from probe vehicles traveling a current route in order to associate the information as attributes of corresponding road sections in a digital street map. The attributes provide navigation information for the vehicle to travel a particular route. The German '844 reference stores static and dynamic parameters for the detected route in the digital map. These static parameters include structural characteristics of the path driven. The dynamic parameters are continually adapted to the real conditions of the detected route street sections in order to determine a vehicle drive route. Both of these systems attempt to provide reliable traffic guidance and navigation information.
All of the above-described known systems utilize DGPS position information in conjunction with conventionally obtained digital road maps in order to assist in navigation by determining preferred routes and/or by providing traffic monitoring information. In the future, advanced safety and navigation applications in vehicles will require highly accurate and detailed digital maps useful in conjunction with the global positioning systems. The construction of such detailed digital maps has not previously been readily possible due to the expensive and time-consuming nature of manual lane measurements over countless road miles in the road networks.
Attempts have been made at automated mapping systems. For example, the reference “Positioning Accuracy of the GPSvan”, Proceedings of the
52
nd
Annual National Technical Meeting of the Institute of Navigation, pp. 657-665, Palm Springs, Calif., 1995, describes a special-purpose, labor-intensive effort to exhaustively map a target area. Here, a specially equipped vehicle in the form of a GPSvan combines numerous sensors, including multiple GPS receivers, laser cameras and stereo vision systems, to capture detailed information about the roadway traveled upon. Such vehicles are, however, prohibitively expensive and require dedicated personnel to encode features as the vehicle drives.
There is therefore needed an automatic method and system to develop, refine and augment digital maps to provide the requisite geospatial accuracy for future fields relating to safety, navigation, marketing, etc.
The present invention meets these needs by developing geospatial information concerning a particular area using a plurality of uncoordinated probe systems moving in the area. The method includes the steps of obtaining probe system specific geospatial information of a lower quality from the plurality of probe systems moving in the area. Next, the probe system specific information is combined over time into a data set. The data set is then analyzed to determine higher quality geospatial information for the particular area. This “data-mining” system and method can be used to develop and/or refine digital maps based on position traces (the geospatial information) generated from the probe systems equipped with global positioning system receivers having differential corrections.
Although the method and system according to the present invention will be described in detail with reference to probe vehicles providing positional trace information to refine and augment commercially available digital road maps, it will be understood that the invention is more generally applicable to using uncoordinated probe systems, having only poor or moderate quality GPS receivers, to develop geographical databases, such as maps, that are of a medium to high quality. Moreover, the probe systems can refine and augment any known database having a geographic component using a suitable number of position traces obtained from the probe systems, be they vehicular or otherwise.
According to the invention, a large number of probe vehicles are equipped with a position/time sensor to record their position and time whenever the probe vehicle is in motion. Other sensors and data types may also be combined with this data. In fact, the time data is not even necessary. The probe vehicles are driven in their normal fashion such that, over a period of time, all possible road routes will be traversed by at least one of the probe vehicles. The data from the probe vehicles is combined into a data set, either in real-time or via post-processing. This data set is then subject to statistical and/or other forms of analysis to identify various features. Based upon the data from many probe vehicles, its combination provides highly accurate measurements of the physical environment. A map is then generated from the accurate measurements. This thus provides a probabilistic approach to generating a map which is advantageous for autonomous vehicle applications in that it describes how people actually behave on a road network. Further advantageously, statistical evaluation of the data set provides information apart from the road geometry, such as traffic control information. When the position data is combined with data from other vehicle sensors, such as traction control, suspension, turn indicators, vision systems, automotive radar, etc., it becomes possible to locate other environmental conditions such as potholes, dirt roads, ice on the roads, guard rails, etc.
In a particular embodiment, the present invention advantageously builds and/or enhances digital road maps, which serve as a baseline map, with geospatially specific information by mining massive amounts of differential global positioning system (DGPS) trace data from uncoordinated probe vehicles.
When building the digital road map, the initial trace data from the uncoordinated probe vehicles serves as a base line map, which is refined based on the additional trace data. When augmenting or enhancing a commercially available digital road map, the data from the commercially available digital road map serves as the base line map, with the addition
Langley Patrick Wyatt
Rogers Seth Olds
Wilson Christopher Kenneth Hoover
Crowell & Moring LLP
Daimler-Chrysler AG
Nguyen Tan
Tran Dalena
LandOfFree
Method and system for autonomously developing or augmenting... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for autonomously developing or augmenting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for autonomously developing or augmenting... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2840132