Abstract: A navigation system includes a driving profile program. The driving profile program collects information about an end user's driving activity. The information relates to trips made by the end user. The information includes departure times, intermediate stops, arrival times, purposes of the trips, and so on. After collecting this information over a period of time, the driving profile program analyzes the end user's driving activity. The driving profile program provides the end user with a driving activity profile. In addition, the driving profile program determines ways to reduce the amount of time and/or expense that the end user spends traveling in his/her vehicle and suggests modifications to the end user's driving activity that would save the end user time or expense.

Abstract: The invention provides a method and system for providing route guidance and other information from a base unit to a remote unit in response to a request from the remote unit. A query is formatted at the remote unit, the query including the request, and is transmitted from the remote unit to the base unit. Requested route guidance information is calculated at the base unit in response to the query, using a large up-to-date database located at the base unit. A response to the query is formatted at the base unit, the response including route guidance information. The response is then transmitted from the base unit to the remote unit for display. The transmission is made in a compact form through the use of maneuver arms and combined maneuver arms and through the use of tokenized forms. A maneuver arm represents a road at an intersection, for depiction on a display, by one or two endpoint coordinates.

Abstract: System and method are provided for route calculation for use with a navigation system and used with a map database with attributed no-outlet and circular segments. A route calculation program adapted to find at least one solution route, between a first location and a second location on a road network, identifies a segment with a first node and a second node in the road network. From an attribute stored in the map database, the program determines whether the first node is connected to the road network and the second node is connected to an isolated portion of the road network. Using the attribute, the route calculation program determines whether to explore the isolated portion of the road network. In some instances, the program refrains from exploring the segment leading into the isolated portion of the road network and the isolated portion of the road network itself.

Abstract: A data compression method and system that include the substitution of a substring of data characters located at a first position in a stream of data characters with a substitution code. The substitution code includes a reference to a previous position in the stream of data characters at which is located a substring of data characters that matches the substring of data characters which are being substituted located at the first position. The substitution code also includes an indication of the size of the substituted substring. The reference in the substitution code is a backwards offset to the previous position relative to the first position. According to a further aspect, Huffman encoding can be applied to the backward offsets, the substring lengths, the consecutive literal character lengths, and the literal characters themselves to reduce the data requirement size.

Abstract: A database architecture for using geographic data to provide navigation-related functions is disclosed. The navigation-related functions are provided by navigation program applications. A geographic database is stored on a medium and includes data representing geographic features and has a plurality of indexes into the data. A data access layer accepts requests from the navigation program applications for geographically-referenced data, accesses the geographic database and provides responses to the requests from the navigation program applications for geographically-referenced data. Logic rules are associated with the geographic database. The data access layer includes a deductive database engine that accesses and combines the logic rules to determine how to use to the indexes to access the data from the medium and to convert the data from a format in which they are stored on the medium into a format that the navigation program applications can use.

Abstract: A method implemented on a navigation system in a vehicle for determining the position of the vehicle relative to a road network. The navigation system uses a geographic database that contains data that represent positions of roads upon which the vehicle travels. Using the output from a GPS system, and optionally outputs from other sensors, the navigation system matches the positions of the vehicle to the locations of the roads represented by the data contained in the geographic database. Upon detecting an event from which the position of the vehicle with respect to the roads represented by the data contained in the geographic database can be determined with a relatively high degree of accuracy, a correction factor is determined. The correction factor is an offset (i.e., a distance and direction) of the GPS position reported during the event to the known-to-be-highly-accurate position. The correction factor is then used to adjust subsequently obtained GPS readings for a limited period of time, i.e.

Abstract: A method and system for organizing and storing map data that facilitates use of the map data by navigation application programs such as those in navigation systems. The map data represent geographic features located in a region. The map data are organized into parcels such that each parcel contains a portion of the map data. The map data contained in each parcel represent those geographic features contained in a corresponding separate one of a plurality of rectangular areas located in the region. Each rectangular area has a uniform dimension in a first coordinate direction but has a dimension in the other coordinate direction such that the map data that represent the geographic features contained in the rectangular area are close to, but do not exceed, a maximum data size for a parcel.

Abstract: An in-vehicle navigation system includes a receiver for receiving real-time traffic information (RTTI), a database for storing routine trip information, and a processor for running a regular route application. The regular route application includes a learning mode program and an operational mode program. The learning mode program records information regarding trips regularly taken by a vehicle and populates the database with records of routine trip information. The recorded trip information can include driver identifiers, trip departure times, origin points, destination points, dates of travel, days of travel, and route data. When the vehicle begins a new trip, the operational mode program determines whether the vehicle is engaging in a routine trip. This is accomplished by comparing current vehicle location or departure time information to routine trip information in the database.

Abstract: A navigation system includes a feature that allows a user to specify a type of point of interest (or business chain) and then receive a reminder when the user is in proximity to a location of the point of interest of the specified type (or business chain) while traveling in a geographic region.

Abstract: A computing architecture for a motorized land-based vehicle is disclosed. The computing architecture includes a data network comprised of a plurality of interconnected processors, a first group of sensors responsive to environmental conditions around the vehicle, a second group of sensors responsive to the vehicle's hardware systems, and a map database containing data that represent geographic features in the geographic area around the vehicle. A vehicle-environment modeling program, executed on the data network, uses the outputs from the first and second groups of sensors and the map database to provide and continuously update a data model that represents the vehicle and the environmental around the vehicle, including geographic features, conditions, structures, objects and obstacles around the vehicle. Vehicle operations programming applications, executed on the data network, use the data model to determine desired vehicle operation in the context of the vehicle's environment.

Abstract: A method and system that provides end users with the ability to exchange routing data. A route recorder application on a first computing system provides a first end user with the ability to define a route formed of specific road segments and store data that represent the route in a data file. The data file is distributed to a second end user who uses the data that represent the route in a second computing system to provide guidance for following the route.

Abstract: A method for calculating a distance between a first point and a second point using linear interpolation is provided. The first point and the second point are located between a first latitude and a second latitude. An interpolated prime vertical radius of curvature value for a point between the first point and the second point is calculated based on a first prime vertical radius of curvature value for the first latitude and a second prime vertical radius of curvature value for the second latitude. An interpolated meridian radius of curvature value for the point between the first point and the second point is calculated based on a first meridian radius of curvature value for the first latitude and a second meridian radius of curvature value for the second latitude. An interpolated cosine value for the point between the first point and the second point is calculated based on a value representing a cosine of the first latitude and a value representing a cosine of the second latitude.

Abstract: Methods for comparing three-dimensional space curves are provided. Such methods are particularly useful for map matching in in-vehicle navigation systems as well as for other applications that require accurate positioning of the vehicle with respect to the underlying map data referenced by the system. Additionally, they are useful in measuring and/or evaluating the accuracy of a geographic database. Two angles that define the angular orientation of a three dimensional space curve are determined at corresponding locations for each of a first space curve and a second space curve. The variance of the relationship between the angle pairs at corresponding locations along the first and second space curves is utilized to determine the similarity between the first and second space curves despite any spatial translation and angular rotation between the first and second space curves.

Abstract: A text placement program is disclosed. The text placement program provides for placement of text, such as names of geographic features, on a map image. A plurality of candidate locations for text placement are identified and provided to the text placement program. The text placement program evaluates each candidate location for text placement using an expression that includes a weighted clause of a first type indicative of whether the represented geographic feature is named at least once on the map image. If a candidate location being evaluated for text placement overlaps another candidate location, the expression for the candidate location being evaluated includes a weighted clause of a second type. One additional weighted clause of the second type is included for each occurrence of the candidate location overlapping another candidate location. For each candidate location, the text placement program evaluates the expression for two conditions: placement of text and no placement.

Abstract: A data collection system including a data glove is used by a researcher to safely and efficiently collect and input data for a geographic database. The data collection system is transported by the researcher along roads in a geographic area. As the data collection system is being transported, the positions of the data collection system are determined. The researcher inputs data into the data collection system through the glove by hand and/or finger gestures. The data collection system stores data indicating a determined position with a type of data associated with the gestures. The data obtained by the data collection system is displayed so that the researcher can add or modify data records in the geographic database. The data obtained by the data collection system is used to add data to or modify data in the geographic database.

Abstract: A method for comparing geometric shapes to each other is disclosed. When used for vehicle positioning, the present method determines which map path of several candidate map paths best matches an actual path traveled by the vehicle as measured by sensors. The vehicle path and each candidate map path are generalized to a given degree of generalization, thereby yielding an overall trend of the vehicle path and overall trends of each of the candidate map paths. The trend of the vehicle path is compared to the trend of each of the candidate map paths. Based on these comparisons, one or more candidate map paths may be eliminated. If more than one map path remains, the vehicle path and each of the remaining map paths are generalized again, this time to a lesser degree of generalization, and comparisons are made between the trend of the vehicle path and the trend of each of the remaining map paths. Based on these comparisons, one or more map paths may be eliminated.

Abstract: A method for representing a route along a road network in a geographic region is disclosed. A database includes data representations of intersections of roads in the geographic region. Associated with the data representation for each intersection of roads are data indicating one or more nominal paths through the intersection. The nominal paths through an intersection identify, for each road segment by which the represented intersection can be entered, one and only one road segment from which the represented intersection is exited. The route is represented by indicating each intersection at which the route deviates from the nominal path into the intersection.

Abstract: A method for updating a geographic database is disclosed. Data collecting equipment is installed in each of a plurality of vehicles each of which also has a navigation system. The data collection equipment is used to collect data while the vehicles are being driven along roads by their respective users. In addition, a method for assigning a confidence level to geographic data is disclosed. The confidence level is assigned to the geographic data as an attribute. In addition, a method for determining a position of a vehicle by sensing roadside structures is disclosed. Data indicating positions of roadside structures are contained in a geographic database. By matching positions of sensed roadside structures to data in the geographic database that indicates the positions of the structures, the position of the vehicle while traveling can be determined.

Abstract: A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes a plurality of data records of a first type and a plurality of data records of a second type. The plurality of records of the first type are organized into a plurality of parcels, each of which includes a plurality of data records of the first type and the plurality of records of the second type are organized into a plurality of parcels, each of which includes a plurality of data records of the second type. The parcels of data records of the first type are interleaved with the parcels of data records of the second type. This interleaving enables navigation functions that use these different types to access these different types more quickly and efficiently, thereby enhancing navigation system performance.

Abstract: A turn detection algorithm is used by a navigation system for determining position and heading of a vehicle relative to a road network represented by a geographic database used by the navigation system. A dead-reckoned position and heading are determined along a plurality of road segments in the road network using sensor measurements of a distance traveled by the vehicle and a change in heading of the vehicle. A vehicle trajectory history is formed and then continuously updated. The vehicle trajectory history includes sensor-derived data representing the vehicle trajectory over a relatively small, chosen distance. The sensor-derived data in the vehicle trajectory history include total turn (i.e., heading change of the vehicle), vehicle state (e.g., travelling straight, turning or reversing in turn direction within a specified small distance) and type of vehicle maneuver. These data represent the trajectory of the vehicle for that distance and are kept in a memory.