Abstract: A map display control apparatus for a motor vehicle including a road map storage device which stores road map data relating to a road map. A bird's-eye view data converting circuit converts the road map data into bird's-eye view data so that the road map is displayable on a display device according to a bird's-eye view method in which the road map is obliquely looked down from above. A display control circuit controls the display device to display the road map according to the bird's-eye view data on the display device, wherein the display control circuit controls the display device to display an image representative of a sky in a part of the display device that is close to an upper side of a display screen of the display device.

Abstract: A map database apparatus according to the present invention manages roads by expressing the roads as link strings. Each of the link strings is constituted by connecting a plurality of links, each of the links has nodes at a front end and a rear end respectively, the map database apparatus has node information concerning the nodes, and the node information includes guide data to be used for route guidance. And, the guide data have directional characteristics corresponding to an order in which the links are connected.

Abstract: The present invention is related to a stereoscopic map displaying method beneficial for a navigation system in which map information is selected from a map database according to a current location of a mobile object. The map database for storing map information comprises a plurality of types of information regarding a first map mesh provided with height information and a second map mesh with no height information wherein there is provided information for identifying that the second map mesh has no height information.

Abstract: A navigation apparatus includes: a first position information generating device that generates first position information as current position information regarding the navigation apparatus based upon a signal received from outside; a second position information generating device that generates second position information as current position information based upon another signal received from outside; and a control device that implements control to provide route guidance based upon current position information and map information. And the control device uses the first position information as effective current position information if a position corresponding to the first position information generated by the first position information generating device is within an error range set for a position corresponding to the second position information generated by the second position information generating device.

Abstract: In a navigation system using a bird's-eye view display mode, map data on a plan view map are subjected to a perspective projection conversion to obtain drawing data on a bird's-eye view map. In this case, an input of the position of a view point is accepted, and a projection plane for a bird's-eye view is determined on the basis of the coordinates of a current position and a destination and the position of the view point so that the display positions of the two points which have been subjected to perspective-projection conversion are coincident with predetermined positions. Alternatively, an input of a scale is accepted, and the position of the view point and the projection plane are determined on the basis of the coordinates of the two points and the scale so that the display positions of the two points after the perspective projection conversion are coincident with predetermined positions and the drawing scale is coincident with the input scale.

Abstract: There is provided an in-vehicle mount type navigation device in which a user can freely set a desired destination or via-places through which a route extending to the destination passes. A memory is provided with a destination/via-place table for storing data representing the destination and the via-places through which the route extending to the destination passes. A destination/registration place setting unit in a microprocessor stores data representing a place to be added in association with any specified one of a position between a via-place and another via-place or destination, and a position next to the destination into the destination/via-place table. On the basis of the data stored in the destination/via-place table, the guide route calculator of the microprocessor calculates a guide route which successively passes through the via-places and extends to the destination.

Abstract: The present invention is related to a stereoscopic map displaying method beneficial for a navigation system in which map information is selected from a map database according to a current location of a mobile object. The map database for storing map information comprises a plurality of types of information regarding a first map mesh provided with height information and a second map mesh with no height information wherein there is provided information for identifying that the second map mesh has no height information.

Abstract: Whether the structure data read from the map data correspond to a non-decomposition structure or a decomposition structure, the drawing attribute of the mesh boundary is modified for the decomposition structure, and textures such as windows are mapped on the side wall of the structure by mapping the texture on the side wall of the structure reconstructed after reconstructing the single-bodied structure before decomposition, or mapping the texture progressively on the side wall of the decomposition structure with the stored start point and end point of the texture to be mapped.

Abstract: A navigation apparatus for displaying most appropriately information such as character strings, routes, etc., when a map is displayed by bird's-eye view display. The navigation apparatus includes a portion for calculating the present position on the basis of information from sensors, a portion for executing perspective conversion operation for displaying a map by bird's-eye view display, a portion for disposing the present position or the present position and a position representing a destination at the most suitable positions, a portion for controlling so that overlap of character strings can be eliminated, a portion for controlling the same character strings, a portion for displaying most appropriately a background such as lines and planes, a portion for controlling marks to be displayed, and a portion for executing graphic plotting by using the resulting map data.

Abstract: A map database apparatus is provided in which: meshes that are achieved by dividing a map into a plurality of portions are used as management units; sets of data related to the meshes are stored in a specific order; a management table that manages the sets of data related to the meshes is provided; and the management table has a parameter that makes it possible to determine an access address of a set of data related to a mesh present in a surrounding area of a specific mesh through calculation based upon the specific mesh.

Abstract: In a navigation system that reports on a traffic control point and a traffic jam location by voice on a route, various types of traffic information are received by an FM multiplex receiver. If the received traffic information includes information on traffic jams on the recommended route that has been set, the distance from the current position to the tail end of the traffic jam location is calculated and is reported by voice through a speaker.

Abstract: The method entails using three dimensional map data including information Indicating horizontal locations of map constituent elements such as topographical features, roads, buildings and information indicating heights or elevations or altitudes of at least some of the map constituent elements located in parts of available horizontal map area. A perspective map looking from a view point toward a ground plane is generated by executing coordinate transformation procedures on the map information, and a scenery Image corresponding to the perspective map is displayed on a display device. The view point for generating the perspective map Is established above a height of a map element existing at a location specified in response to the current location of the moving object, and the height of the view point Is renewed with movement of the object. The view point setting unit repeats Its view point setting procedure when renewed location information has movement of the moving object.

Abstract: A route along which a user can use facilities set as stopovers is searched; when the user sets facilities relevant to a toll road as a stopover of a route to a destination, only links of toll roads around the facilities are set as target links, and a route passing via nodes of links in the neighborhood of the facilities is searched by a processor.

Abstract: There is provided a map display device and a navigation device for displaying a three-dimensional map in which information which is originally hidden can be displayed on a display frame (screen). The map display device (navigation device) includes a map storing unit for storing three-dimensional data of each map constituent, and a map display unit for forming a three-dimensional bird's-eye view map which is obtained by projecting onto the plane from a desired view point each map constituent which is specified by the three-dimensional data stored in the map storing unit, and displaying the three-dimensional bird's-eye view map thus formed on a display frame (screen).

Abstract: To display a current position of a vehicle along a road in a stereoscopic map drawn based on three-dimensional map data, a navigation device forms a picture image superposing the current position of the vehicle on a perspective map viewing a three-dimensional ground surface from a direction forming a predetermined angle with respect thereto based on data read from a map data base and displays the image on a screen of a display and a position correcting unit 52 calculates an altitude at a position in the map in correspondence with the current position of the vehicle based on altitude data read from the map data base.

Abstract: A map display apparatus for displaying perspective image of a map. The apparatus includes an image display device for displaying the perspective image of the map and a map data storage device for storing map data. Map drawing means is included for preparing map drawing data using the map data and for displaying a perspective image of the map on the display device on the basis of the drawing data. The map drawing means transforms coordinate data of a map into data suitable for display of the perspective image of the map. The data transformation is accomplished by perspectively projecting the coordinate data onto a predetermined projection plane with a view point at a desired position. The projection plane is determined on the basis of two predetermined points in the map data, such as the current position of a vehicle and the destination, so that drawing positions of the two points after the perspectively projecting operation are coincident with predetermined positions.

Abstract: A map database apparatus according to the present invention stores a plurality of sets of link string data provided separately to correspond to maps at different scales representing a road as a link string constituted by connecting a plurality of links each having a node at a front end and a rear end thereof. In the map database apparatus, a level correlation link number is provided as data that indicate a link string in a lower order level at a larger scale that is common to a link in a higher order level at a smaller scale, the level correlation link number having a level number of the higher order level and a link number of the common link in the higher order level.

Abstract: A navigation system which can enhance the position determining accuracy of a mobile object without employing any high precision measuring instrument. The navigation system comprises a GPS range measuring device, an angular velocity measuring device, a velocity measuring device and an azimuth measuring device, which measure the motion of the mobile object; a GPS range error estimating device, an angular velocity error estimating device, a velocity error estimating device and an azimuth error estimating device, which estimate errors involved in the respectively corresponding measuring devices; and a position calculating device which calculates the position of the mobile object from the outputs of the error estimating devices. The error estimating devices are implemented by Kalman filters and averaging processes.

Abstract: A navigation system which provides easy-to-understand route guidance using landmarks. Once a guided route is determined (201), the system determines the priority of landmarks to be used in route guidance considering such factors as an initial setting, time of day (daytime or nighttime), and user specifications (201), and selects crossings for which route guidance will be given (203). As a mobile unit approaches one of selected crossings (203, 206, 207), the system selects one of landmarks at the crossing and, at the same time, selects guidance phrases based on a relationship between the position of the landmark and running directions in which the mobile unit runs before and after passing through the crossing (209). Then, with the use of the landmark, the system provides guidance information on the running direction after passing through the crossing (210) using the selected phrase.

Abstract: A microprocessor 214 obtains a vehicle travelled distance by multiplying the number of pulses by a distance factor R, the number of pulses having been outputted from a vehicle speed sensor 203 and having been counted by a counter 216. In addition, the microprocessor 214 estimates a current position on a road according to map data read out from a CD-ROM 205 via a driver 206, measured data from an angular velocity sensor 201 and a direction sensor 202 via A/D converters 209 and 210, and the obtained vehicle travelled distance. The road direction on the estimated current position and the vehicle direction obtained from the measured data of the angular velocity sensor 201 and the direction sensor 202, are compared, and in accordance with the angular difference therebetween and the information whether the driving road is a left turn or a right turn, it is determined whether the estimated current position is ahead or behind the actual position. With the result, the distance factor R can be dynamically modified.