Abstract: A vehicle positioning application in a navigation system provides for determining a change of vehicle heading using differential wheel speed sensors and compensates for dynamic and static changes in the wheel radii.

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 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: 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 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 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.

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: 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 navigation system provides a user thereof with warnings or advisories about toll gates that require exact change. The warnings or advisories are provided when the navigation system calculates a solution route to a destination specified by the user. The warnings or advisories are also provided when the user queries the navigation system about a particular specified portion of a road. The navigation system uses a geographic database that includes data about roads in a geographic region. The geographic database includes data about toll gates located along portions of roads including data about whether a toll gate along a portion or a road requires exact change.

Abstract: A data construction for storing data efficiently and a method for forming and using the data construction is disclosed. The method comprises representing a set of actual data values from an original source of data with an alternative representation. One or more parameters of a formula are determined to approximate the set of actual data values in the original source of data. For each actual data value in the original source of data, the difference between the actual data value and the value predicted therefor by the formula is determined. The difference for each actual data value is stored in a data construction on the medium along with the one or more parameters. The alternative representation preserves the information content of the actual data values from the original source of data while reducing the storage requirements for storing the information on a medium.

Abstract: A feature implemented on a navigation system in a vehicle whereby the user of the vehicle selects one or more types of audio programs and associates each type of audio program with a specific location along a predetermined route. As the vehicle is being driven along the route, audio programs of the types selected by the user are obtained and stored in a memory. When the vehicle reaches the location associated with one of the selected types of audio programming, the stored audio program of the selected type is presented to the user.

Abstract: A system and method are disclosed that allow a navigation system that uses a geographic database to also use the data in traffic messages broadcast by a traffic broadcast system. One aspect of a present system and method includes the formation, storage, and use of location reference data records in a geographic database used by a navigation system. These location reference data records identify certain other kinds of data records that represent physical geographic features, such as data records that represent segments of roads, as being associated with certain location reference numbers. These location reference records may be included in a geographic database installed in the vehicle or may be provided to vehicles via a wireless communication link.

Abstract: A system and method are disclosed that make a navigation system easier to use. According to one aspect of the disclosed system and method, an end-user is permitted to define at least one preferred cities list. The cities included on the preferred cities list are selected by the end-user from all the available cities that are represented in the geographic database used by the navigation system. Thereafter, when the preferred cities list is in use and the end-user operates the navigation system to provide a function that requires that the end-user make a selection of a city, the end-user is presented with a list of the cities from the preferred cities list instead of all the available cities represented in the geographic database used by the navigation system. The preferred cities list is not restricted to cities, but may also include any kinds of places or administrative areas.