JP2002243470A - Map display device and program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stereoscopically display buildings in such a way as to match an actually viewed landscape during travel at a place higher than a road on flat land. SOLUTION: The map display device for stereoscopically displaying the buildings is provided with a present location determining means (4) for determining the present location of a vehicle, an information storage means (3) for storing building data with two-dimensional coordinate and height information, an image drawing control means (4) for stereoscopically drawing the images of the buildings on the basis of the two-dimensional coordinate an height information stored in the information storage means, and a display means (6) for displaying the buildings of which the images are drawn by the image drawing control means. Further, the device adjusts the heights of the buildings, and draws the images on the basis of the height of the present location determined by the present location determining means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map display device and a program for three-dimensionally displaying a building.

[0002]

2. Description of the Related Art A vehicular navigation device having a route search and route guidance function displays a building such as a road or a building in a bird's eye view so that information on a traveling direction can be provided in an easily understandable manner. Japanese Patent Laid-Open No. 2000-32 proposes a three-dimensional display of a building.
1974).

[0003] In the conventionally proposed three-dimensional display of a building, since the three-dimensional display is performed irrespective of the height of the road on which the vehicle is currently traveling, the vehicle travels up or down a multi-story road. Buildings are displayed at the same height. Also, even if you are traveling on an elevated,
Buildings that look the same as when driving on a flat ground road are displayed on the map. Therefore, the guide map in which the building is displayed in three dimensions is different from the scenery that can be actually seen.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to three-dimensionally display a building so as to match a scenery which can be actually seen while traveling on a place higher than a flat ground road. Is to do so.

For this purpose, the present invention provides a map display device for displaying a building in three dimensions, in which current position determining means for determining a current position of the vehicle and building data having two-dimensional coordinates and height information are stored. Information storage means, drawing control means for three-dimensionally drawing a building based on the two-dimensional coordinates and height information stored in the information storage means, and a display for displaying the building drawn by the drawing control means Means, and wherein the drawing control means draws by adjusting the height of the building based on the height of the current position determined by the current position determining means. The present invention also provides a map display device for displaying a building in three dimensions, a current position determining means for determining a current position of the vehicle, building data having two-dimensional coordinates and height information, and road attribute information. Information storage means for storing road data having: a drawing control means for three-dimensionally drawing a building based on two-dimensional coordinates and height information stored in the information storage means; and a drawing control means for drawing by the drawing control means. Display means for displaying the building which has been drawn, wherein the drawing control means performs drawing by adjusting the height of the building according to the attribute of the road on which the vehicle is currently traveling. Further, the present invention provides a map display program for displaying a building in three dimensions, wherein the building height is adjusted based on building data having two-dimensional coordinates and height information and the height of the current position of the vehicle. It is characterized by drawing.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a map display device according to the present invention, in which display conditions, coordinate conversion parameters, and route guidance when a map is developed and displayed from map data having two-dimensional coordinates and height information. Device 1 for inputting information about the current position of the vehicle, map data having two-dimensional coordinates and height information, navigation data necessary for route calculation, route guidance An information storage device 3 in which necessary display / voice guidance data and a program (application and / or OS) for displaying a map, calculating a route, and providing guidance, and the like; a map display process as a navigator processing unit; A central processing unit 4 that performs route search processing, display / voice guidance processing necessary for route guidance, and further controls the entire system. For example, an information transmitting / receiving device 5 for transmitting and receiving road information and traffic information, detecting information on a current position of a vehicle, and transmitting and receiving information on a current position, a display and a speaker for outputting information on route guidance, and the like. Of the output device 6. That is, an example is shown in which the map display device according to the present invention is applied to a navigation device.

The input device 1 has a function of selecting a map, inputting a destination, and instructing the central processing unit 4 to perform a navigation process according to a driver's will. As a means for realizing the function, a remote controller such as a touch switch or a jog dial for inputting a destination as a telephone number or coordinates on a map or requesting route guidance can be used. Further, the present invention includes a device for performing a dialogue by voice input, and functions as a voice input device. Further, a recording card reader for reading data recorded on an IC card or a magnetic card can be added. In addition, an information center that stores data necessary for navigation and provides information through a communication line at the request of the driver, and a portable type that has data such as map data, destination data, simple maps, and building shape maps A data communication device for exchanging data with an information source such as an electronic device can also be added.

[0008] current position detecting device 2 is intended to obtain the current position information of the vehicle including height information by using a satellite navigation system (GPS), an absolute direction by the traveling direction of the vehicle, utilizing for example geomagnetism An absolute azimuth sensor for detecting the traveling azimuth of the vehicle, for example, a steering sensor, a relative azimuth sensor for detecting the relative azimuth by using a gyro sensor, for example, a distance sensor for detecting the traveling distance of the vehicle from the number of rotations of the wheels, a vehicle And a sensor for detecting current position information including height information by detecting the acceleration of the vehicle.

The information storage device 3 is an external storage device that stores navigation programs and data, and is composed of, for example, a CD-ROM. The program includes a program for performing a process such as a route search, a processing program shown in a flowchart described in the present embodiment, a display output control required for the route guidance, a program for performing an interactive guidance by voice input, and a program for the guidance. Data, a program for performing voice output control necessary for voice guidance, and data necessary for the program are stored. The stored are data, map data including building shape map data, search data, guidance data, map matching data, destination data, registered point data, road data, image data of the intersections such as branch points, genre data, It consists of files such as landmark data and stores all data necessary for the navigation device. The map data is stored in the form of a rectangle divided into blocks of a predetermined unit. The present invention is also applicable to a type in which only data is stored in a CD-ROM and a program is stored in a central processing unit. Here, as the information storage device,
CD-ROM just not DVD-ROM or the like of the optical disk, magnetic disk such as a floppy disk, may be a magneto-optical disk such as an MO.

The central processing unit 4 includes a perspective display control unit 11 for controlling a three-dimensional display of a building, and a coordinate conversion unit for performing coordinate conversion for displaying a map including a building in a perspective map. 12, a drawing control unit 14 including a conversion parameter 13 for converting coordinates into a perspective map, a CPU executing various arithmetic processing, and reading and storing a program from a CD-ROM of the information storage device 3. ROM storing a flash memory, a program (program reading means) for performing program check and update processing of the flash memory, point coordinates of a set destination, road name code No. The RAM is configured to temporarily store the searched route guidance information and the data being processed. Further, even omitted illustrated In addition, the frame memory, or perform interactive processing by voice input from the input device 1, the audio output control signal from the CPU for storing data to be displayed on an output device such as a display , A phrase read from the information storage device 3 based on the
A voice processor for synthesizing a single sentence, sound, etc., converting it into an analog signal and outputting it to a speaker, a communication interface for exchanging input / output data by communication, and a sensor for capturing a sensor signal of the current position detecting device 2 It has a sensor input interface, a clock for writing the date and time in the internal diagnostic information, and the like. Note that a program for performing the above-described update processing may be stored in an external storage device.

The program according to the present invention and other programs for executing navigation may all be stored in a CD-ROM as an external storage medium, or a part or all of these programs may be stored in a ROM 42 of the main body. May be. Various navigation functions are realized by inputting data and programs stored in the external storage medium as external signals to the central processing unit of the navigation apparatus main body and performing arithmetic processing.

Further, the program according to the present invention, other programs for executing navigation, and part or all of map data are transmitted from an information center (Internet server, navigation server) to a plurality of base stations (Internet provider terminals or vehicles). And a communication station connected by communication). Then, the central processing unit 4 on the terminal side receives the information transmitted from the base station by the information transmitting / receiving device, downloads the information to a readable / writable memory (for example, a RAM, a flash memory, or a hard disk) in the central processing unit 4 and executes the program. , Various navigation functions may be realized. Here, the program may be stored in a flash memory, and the map data may be stored in a separate readable and writable memory such that the program and map data are stored in a RAM, or may be stored in the same readable and writable memory. You may. Alternatively, a program or map data may be partially or entirely downloaded from an information center to a removable storage medium (for example, a memory stick or a floppy (registered trademark) disk) using a personal computer at home.
By connecting the storage medium to the central processing unit 4 and executing the program in the storage medium, various navigation functions may be realized.

The navigation apparatus according to the present invention reads a program from the CD-ROM of the external storage device or a relatively large-capacity flash memory or CD for reading a program downloaded from an information center or the like as described above. A small-capacity ROM storing a program for performing processing (program reading means) is built-in.
The flash memory retains stored information even when the power is turned off, that is, is a nonvolatile storage unit. And C
As a start-up process of D, a program in a ROM serving as a program reading means is started, and a program stored in a flash memory is checked.
The disk management information of the D-ROM is read. The program loading process (update process) is performed based on this information and the state of the flash memory.

The information transmitting / receiving device 5 is a GPS receiving device that obtains information using a satellite navigation system (GPS);
Using a VICS information receiving device, a mobile phone, a personal computer, etc. to obtain information using FM multiplex broadcasting, radio wave beacon, optical beacon, etc., enables bidirectional information exchange with an information center (for example, ATIS) and other vehicles. It is composed of a data transmitting / receiving device for communicating with the device.

The output device 6 has a function of outputting guidance information by voice and / or screen when the driver needs it, and a function of printing out data or the like subjected to navigation processing by the central processing unit 4. As means for this, the data processed by the central processing unit 4 and the information storage device 3
A memory for developing and drawing the data stored in the memory on the screen, a display for displaying the image data drawn in the memory, and printing out the data processed by the central processing unit 4 and the data stored in the information storage device 3 A printer and a speaker for outputting route guidance by voice are provided.

The display is composed of a simplified liquid crystal display and the like, and is an intersection enlarged map screen developed and drawn based on map display data and guidance data processed by the central processing unit 4, a destination name, a time, The distance, the traveling direction arrow and the like are displayed. The image data displayed on the display is 2
It is value image data (bitmap data), and the display data and the guidance data of the map processed by the central processing unit 4 are received using a communication line used for serial communication or the like, and are also used as other communication lines. After rendering and drawing in the memory in the output device 6, the designated display range is displayed on the screen of the display.

This display is provided in the instrument panel near the driver's seat, and the driver can check the current position of the own vehicle by looking at the display and obtain information on a route from now on. . Also,
Although illustration is omitted, using a tablet including a touch panel, a touch screen, etc. on the display screen of the display,
By touching or tracing the screen, a point input, a road input, or the like may be performed.

Next, an example of the structure of data used in a vehicle navigation device provided with the map display device of the present invention will be described. FIG. 2 and FIG. 3 are diagrams showing a configuration example of main data files stored in the information storage device, and FIG. 4 is a diagram showing an example of a data structure of a building shape map. FIG. 2A shows a part of a road map data file. For each of the number n of roads, the road number, length, road attribute data, address of shape data, size and address of guide data, size, road Of the height of the node representing the shape of. The road number is the direction (outbound,
Return trip) is set separately. As shown in FIG. 3A, the road attribute data as the road guidance auxiliary information data is data indicating whether the road is an elevated road, next to an elevated road, an underpass, an underpass, or the number of lanes. is there. As shown in FIG. 2B, when each road is divided into a plurality of nodes (nodes), the shape data has coordinate data including east longitude and north latitude for each of the number m of nodes. Said guide data, as shown in FIG. 2 (C), intersection (or branch point) name, caution point data, road name data, road name address of the audio data, the size and address of the destination data, from the data size Has become. As shown in FIG. 3B, the road name data includes expressways, urban expressways, toll roads, and general roads (national roads, prefectural roads, and others).
And the information of the road type of, highway, in the city highway, data indicating the information indicating whether the main line or the mounting road for the toll road,
It is composed of road type data and a type number which is individual number data for each road type. The node height data is, for example, node numbers 1 to i are heights ○ m,
The node numbers i to k are assigned to the guide road data, such as the height xxm, and the node numbers k to m are assigned the height △△ m. This is because if the shape data is provided, each node must have height data, which increases the data amount. The height data includes height and altitude data with respect to surrounding roads and flat terrain.

In the data structure of the building shape map stored in the information storage device 3, for example, as shown in FIG. 4A, data of N buildings are stored next to the number of data N of the building. . The data of each building includes information on the name, address (address), type, shape, height, and details of the building. The name is the name of the building if it is a building, the name of the resident if it is a private house, the name of the facility if it is a facility, the type of road such as "Chuo-dori" or "National Route 1" if it is a road. The street name, and the address (address) is the address of the building. The shape of buildings, the number of coordinates representing the shapes n and its coordinates _{(x 0, y 0),} (x 1, y 1), .........,
(X _n−1 , y _n−1 ), and the type is information on general houses, condominiums, office buildings, public facilities, roads, parks, and the like. The height is information on the floor number and the height (m). When the height is stored in the number of floors, the height is converted into information of height (m) using a table. For example, in the case of a tenant building, details are information on each resident, and the number of names m
And each tenant, name, telephone number, room number, classification (type of business, business such as restaurant, convenience store, ...)
Is information about. Therefore, as shown in FIG. 4B, by sequentially reading out coordinate values as information relating to the shape of the building, connecting and drawing with a line, and displaying it, for example, the planar shape of a building or a house or the topography of a park can be output. it can.

[0020] The present invention, when the three-dimensionally displaying a building on a distance map on the basis of building data with two-dimensional coordinates and height information, during traveling on a road with a position higher than the ground as in the elevated Is to enable a three-dimensional display of a building closer to its appearance by adjusting the height of the building and drawing.

[0021] First, in the two-dimensional coordinate system for the map display performed by the coordinate converting the two-dimensional coordinates of map data to perspective map with depth is described. FIG. 5 is a diagram for explaining a trapezoidal coordinate conversion algorithm, and FIG. 6 is a diagram for explaining a coordinate conversion algorithm for building height data.
The conversion parameters 13 of the central processing unit 4 hold coordinate conversion parameters such as a trapezoid conversion parameter for converting rectangular coordinates of a map into trapezoidal coordinates and a curved surface conversion parameter for converting coordinates of a curved surface into coordinates of a projection plane. . The coordinate conversion unit 12 performs coordinate conversion of map data composed of two-dimensional coordinates based on the coordinate conversion parameters held in the conversion parameters 13. A perspective map is displayed on the screen.

First, trapezoid conversion parameters for performing coordinate conversion to a trapezoid as shown in FIG. 5B for the coordinate space of two-dimensional map data as shown in FIG. 5A will be described. First, as for the rectangle of the two-dimensional map data, a width (a half of the length in the X direction) g is set as shown in FIG. 5A, and for the trapezoid, as shown in FIG. , The length of the upper side (1/2 of the length in the X direction) a and the length of the lower side (1/2 of the length in the X direction) b are set, and the vertical length common to the rectangle and the trapezoid is set. (The length in the Y direction) L is set.

Assuming that the new coordinates converted by the coordinate conversion unit 12 from P (X, Y) of the map data based on these parameters are P1 (sx, sy), first, Y
The coordinate value sy is the sum of the product of the length a of the upper side of the trapezoid and the vertical length L and the product of the difference (ba) between the lengths of the upper and lower sides of the trapezoid and the Y coordinate value ｛aL + (ba ) The ratio of the product b · L · Y of the length b of the lower side of the trapezoid to the vertical length L and the Y coordinate value with respect to Y｝, that is, [Equation 1] sy = {b · L · Y} / ｛a · L + (b-a) Y} = (k 1 Y) / (k 2 + k 3 Y) _{However, k 1 = b · L k} 2 = a · L k 3 =
(Ba). The X coordinate value sx is
The difference between the length b of the lower side of the trapezoid and the length of the upper and lower sides of the trapezoid (b−
a) is multiplied by the Y coordinate value and divided by the vertical length L of the trapezoid to subtract (ba) sy / L, and multiplied by the ratio of the X coordinate value to the length g of the rectangle in the X direction, that is, , Here, k ₄ = g k ₅ = b k ₆ = (b−
a) It is determined by / L.

First, the conversion of the Y coordinate will be described. In FIG. 5A, the equation of the oblique straight line is represented by the following formula: Y = L × X / 2g + L / 2. Therefore, it is assumed that the converted map is such that the diagonal straight line is maintained as a straight line even after the conversion and the X coordinate is equally divided, and this straight line and the X coordinate value in another two-dimensional map data are assumed. Fig. 5
Consider the mesh triangle shown in FIG. Since these are similar, consider the ratio of the lengths of the sides of each triangle. First, the ratio of the vertical length of the triangle is (L-sy): sy
Becomes On the other hand, the length of the base of the triangle is
−Xa / g, and the lower side is b + Xb / g. Therefore,
Since the ratios of the lengths of the sides of the similar triangles are equal, [Equation 4] (L−sy): sy = (a−Xa / g) :( b + Xb /
g) By erasing X from this [Equation 4] and the above [Equation 3], [Equation 1] is obtained. Also, if the X coordinate value of the fixed value g converted to the upper side a and the lower side b is made to correspond to the vertical length sy, then (ba) sy / L. [Equation 2] is obtained by multiplying the ratio with X.

Next, a case where a three-dimensional building such as a building is displayed three-dimensionally by two-dimensional coordinate conversion using trapezoid conversion parameters will be described. For example, when a building has data of a floor n, the average floor height h is multiplied by the floor n to obtain a height as n × h = H. When the data has the height H, coordinate conversion is performed based on the height H. Y coordinate value s of height H at Y coordinate value sy
The coordinate conversion to y 'is performed by using, for example, [Equation 5] on the X coordinate value sx and the Y coordinate value sy converted on the two-dimensional plane.
This can be performed by obtaining an addition value ΔY of the coordinate values.

[0026] However, k ₇ = (ba) / bL = k ₃ / k ₁ Therefore, as shown in FIG. 6A, (sx1, sy
The vertex coordinate value of the building having the height H at the point 1) is represented by the following expression (6) (sx1, sy1 + ΔY) = ｛sx1, sy1 + (1-
k ₇ sy) H｝, and the coordinates converted in this way are connected by a line, the inside of the frame is painted with a predetermined color, and this process is performed in order from the back and overwritten to obtain FIG. ) Can be displayed.

As described above, the trapezoid conversion parameters are:
k ₁ to k ₇ are calculated from or from a, b, g, and L, and coordinate conversion (X, Y) and height h are used to perform coordinate conversion for a three-dimensional building by simple addition, subtraction, multiplication, and division. Can be executed by the calculation of Therefore, not only the building but also a three-dimensional building such as a house or a bridge can be three-dimensionally drawn in the same manner. For example, as shown in FIG. 4, as a data of the building, a coordinate sequence representing the shape of the building (Polygon data) and the floor information of the building (or the height of the building), the coordinates are converted from the two-dimensional coordinate points and the floor information of the building as described above, and a predetermined value is determined from the current position. By drawing only the buildings within the distance, the drawing response can be further improved. As the current position moves, only the buildings within a predetermined distance from the current position can be easily displayed three-dimensionally. be able to.

Further, in the above [Equation 2], after P (X, Y) is changed to P '(X, sy), P1 is calculated using the sy.
Although (sx, sy) has been obtained, sx may be obtained from X and Y coordinate values without using sy. For example, in [Equation 2], when sx 'is obtained using Y for sy, P (X, Y)
Is converted into P1 '(sx', sy) shown in FIG. 5B and swells from a trapezoid, so that the result of coordinate conversion becomes a bowl shape.

By the way, when a building is three-dimensionally displayed, for example, even if the vehicle is running on an elevated road, the same appearance of the building on a flat ground road may be displayed on a map. However, the three-dimensionally displayed guide map differs from the scenery that is actually visible. Therefore, a description will be given of a processing flow for reading the height of the vehicle position relative to a flat ground with reference to road data when traveling on an elevated road or an upper road, and adjusting the height of the drawing building based on the read height information with reference to FIG. First, it is determined whether or not the current traveling position is traveling on an elevated road (step S1). The determination as to whether or not the vehicle is traveling on an elevated road is made based on, for example, whether or not the road is a toll road. Generally, a toll road is higher than a general road, and if it can be recognized that the vehicle is traveling on a toll road, the height of the building is adjusted and displayed three-dimensionally. If the vehicle is not traveling on an elevated road, the height adjustment value is set to zero. If the vehicle is traveling on an elevated road, a process of acquiring height information for a lower road or a flat ground from road data is performed (step S3). Next, it is determined whether or not the height information has been acquired (step S4). If the height information has been acquired, the height adjustment value is set to the height with respect to the acquired flat land (step S5). If the height information has not been acquired, the height is increased. The adjustment value is set to a default value (constant value) (step S6). After setting the height adjustment values in this way, the process enters the drawing processing loop for the number of buildings in steps S7 to S13. That is, the building polygon coordinates and the building height are obtained (steps S8 and S9), the building height is adjusted by subtracting the set adjustment value from the obtained building height (step S10), and the coordinate calculation described above is performed. (Step S11), rendering processing is performed to perform stereoscopic display (Step S12). The above process is looped for the number of buildings, and the process ends.

As described above, when the vehicle is traveling at a position higher than the ground, such as an overpass, the height of the building to be displayed can be displayed lower in accordance with the height, and a three-dimensional display that is closer to the actually visible scenery can be displayed. It can be performed. In general, an expressway is an upper layer and an ordinary road is a lower layer. Therefore, if it can be recognized that the user is traveling on the expressway, it is possible to adjust the height of the building and perform a three-dimensional display. The vehicle includes a GPS positioning device for obtaining the current position information transmitted by the satellite, a device for detecting a vehicle speed pulse corresponding to the vehicle speed, an optical beacon receiving device capable of receiving optical beacon information on a general road, mainly on a highway. A radio beacon receiving device or the like capable of receiving radio beacon information is mounted, and it is possible to determine whether the vehicle is traveling in the upper layer or the lower layer by combining the measurement results of these measuring devices. For example,
G that it is highly probable that you went down the expressway and moved to a general road
The PS and the change in vehicle speed are detected and recognized, and the reception of the optical beacon is possible only on the general road. Therefore, when the optical beacon is received, it can be recognized that the vehicle is traveling on the general road. In addition, it is recognized by detecting changes in GPS and vehicle speed that there is a high possibility that the vehicle has moved from a general road to an expressway. By detecting the change in the number and using the fact that the GPS reception is easy to receive on the upper road (highway), it is recognized that the vehicle is running on the highway, and by using the fact that the radio wave beacon is mainly received on the highway, it is possible to communicate with the upper layer. It is possible to recognize. In this way, when it is determined that the building is the upper layer, the drawing height of the building is adjusted according to the height with reference to the height information of the road data.

In the embodiment shown in FIG. 7, when the currently running road is an elevated road or an upper-level road, height information is obtained, the height of the current position is determined, and the height of the building to be drawn is adjusted. FIG. 8 shows an example in which the height of the currently traveling road is obtained from the road data, the height of the current position is determined, and the height of the building to be drawn is adjusted irrespective of the elevated road or the upper road. ,
This will be described with reference to FIG. FIG. 8 is a diagram showing a processing flow of an example in which the height of a building is adjusted and displayed based on the height of a road on which the vehicle is currently running on a flat ground. The height data for the lower road and the surrounding flatland assigned to the node currently traveling is acquired from the road data (step S2).
1) Then, it is determined whether or not the height data has been obtained (step S22). If the height data has been obtained, the height is set to the height around the obtained adjustment value (step S23). If the height data was not obtained, the adjustment value = 0. (Step S24). After setting the height adjustment value in this way, steps S25 to S31
Into the drawing processing loop for the number of buildings. That is, the building polygon coordinates and the building height are obtained (steps S26 and S2).
7) The building height is adjusted by subtracting the set adjustment value from the acquired building height (step S28), the above-described coordinate calculation is performed (step S29), and the drawing process is performed to perform stereoscopic display (step S30). ). And it ends the process by a few minutes loop building the above processing.

FIG. 9 is a diagram showing a processing flow of an example in which the relative height of the road on which the vehicle is currently running is calculated with respect to the road around the road, and the height of the building is adjusted and displayed. If the height data assigned to the node in the road data is the altitude, the altitude data A assigned to the currently traveling node is acquired from the road data (step S).
41) Based on the currently traveling node, nodes in a predetermined range are extracted, and among the extracted nodes, the altitude data B of the node having the lowest altitude data is obtained from the road data (step S42). Both then determines whether the altitude data is acquired (step S43), if it can be acquired as an adjustment value = A-B (step S44), if it can not be acquired and the adjustment value = 0 (step S4
5). After setting the height adjustment value in this way, step S4
It enters into the drawing processing loop for the number of buildings in 6 to S52. That is, the building polygon coordinates and the building height are obtained (step S
47, S48), the building height is adjusted by subtracting the set adjustment value from the acquired building height (step S49), the above-described coordinate calculation is performed (step S50), and a drawing process is performed to perform stereoscopic display (step S50). Step S51). The above process is looped for the number of buildings, and the process ends.

In the above embodiment, the height of the building is adjusted and displayed based on the height data given to the road data. However, the attribute of the road on which the vehicle is currently traveling is referred to by the road data. Alternatively, the height of the building may be adjusted in accordance with the attribute to be drawn. For example, looking at the attributes of the road on which the vehicle is currently traveling, if it is determined that the road is an expressway or a toll road, it usually travels at a higher position than a general road, The height of the building may be drawn lower than in the case of the inside.

Note that the present invention is not limited to the above example, and various modifications are possible. For example, the degree of lowering of all buildings having height information within a predetermined range (drawing range) from the current position may be determined based on the current position and the position of the building. That is,
Distant structures appear to change much less when a vehicle travels high, than when it travels over the ground.
Therefore, for example, the degree of drawing lower as the distance from the building to the current position may decrease, or the degree of drawing lower as the distance from the current position of the vehicle in the Y-axis direction of the display screen may decrease.

In a device having a function that the current position detecting device can detect the height of the current position, for example, a device using GPS or a device of a type that integrates detection information of an acceleration sensor, the accuracy is not sufficient. Although the height of the current position is not detected, the height of the current position can be detected, and the building may be drawn at a height obtained by subtracting the height of the detected current position from the height of the building. This can be applied when the height data of the road data is not complete.

Further, for example, it is determined whether the road on which the vehicle is traveling is a toll road or a general road. If the road is a toll road, it is recognized that it is the upper layer of the multi-layered road. In addition to displaying the building lower than the height of the building, it may be determined whether the road on which the vehicle is traveling is an intercity highway or an urban highway, and the height may be adjusted and drawn only while the urban highway is running. This is because the inter-city expressway is rarely a multi-layered road, and the number of buildings is small, so that the effect of adjusting the height of the buildings and drawing is small.

If a general road forms a multi-layer road, either the upper layer or the lower layer of the multi-layer road is detected by visual observation or a current position detecting device, and height data is obtained in the case of the upper layer. adjust the height of the building may be drawn.

[0038]

As is apparent from the above description, the current position determining means for determining the current position of the vehicle, the information storing means for storing building data having two-dimensional coordinates and height information, and the information storing means Drawing control means for drawing a building three-dimensionally based on the two-dimensional coordinates and height information stored in the display control means, and display means for displaying the building drawn by the drawing control means. Since the height of the building was adjusted based on the height of the current position and drawn,
The building can be displayed three-dimensionally so as to match the scenery that can be actually seen even when traveling on a place higher than the flat ground such as an elevated road or an upper road. Generally, toll roads and expressways are installed higher than general roads. Therefore, according to claim 6, it is possible to three-dimensionally display the building so as to match the scenery actually seen.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a map display device according to the present invention.

FIG. 2 is a diagram illustrating a configuration example of a main data file stored in an information storage device.

FIG. 3 is a diagram illustrating a configuration example of a main data file stored in an information storage device.

FIG. 4 is a diagram showing an example of a data structure of a building shape map.

FIG. 5 is a diagram illustrating a trapezoidal coordinate conversion algorithm.

FIG. 6 is a diagram for explaining a coordinate conversion algorithm for building height data.

FIG. 7 is a diagram showing a processing flow for adjusting the height of a drawing building.

8 is a diagram depicting a processing flow of another example of adjusting the height of the drawing buildings.

FIG. 9 is a diagram showing a processing flow of another example of adjusting the height of the drawing building.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 input device 2 current position detecting device 3 information storage device 4 central processing device 5 information transmitting and receiving device 6 output device 11 perspective display control unit 12 coordinate conversion unit 13
… Conversion parameters

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C032 HB22 HB23 HB24 HC08 HC15 HC23 HD03 2F029 AA02 AB01 AB07 AC03 AC09 AC14 AC18 AD07 5B050 AA00 BA07 BA17 CA06 EA19 EA27 FA02 5H180 AA01 BB02 BB04 BB13 BB13 FF23 BB13 FF13 CCFF FF38

Claims (8)

[Claims] 1. A map display device for three-dimensionally displaying a building, a current position determining means for determining a current position of the vehicle, and an information storage means for storing building data having two-dimensional coordinates and height information. , 2 stored in the information storage means.
Drawing control means for drawing a building three-dimensionally based on dimensional coordinates and height information, and display means for displaying the building drawn by the drawing control means, wherein the drawing control means A map display device, wherein a height of a building is adjusted based on the height of a current position determined by a determination unit and drawn. 2. The map display device according to claim 1, wherein said drawing control means determines an adjustment amount of a building height based on a current position and a position of the building. 3. The current position determining means has a function of detecting a height of a current position, and the drawing control means adjusts a building height based on the height detected by the current position determining means. 2. The map display device according to claim 1, wherein the image is drawn. 4. The map display device according to claim 1, wherein said current position determination means determines the height of the current position based on road height data. 5. When the road height data is altitude data, the drawing control means calculates a relative height of a currently running road with respect to a surrounding road, and adjusts the height of the building to draw. The map display device according to claim 4, wherein: 6. A map display device for three-dimensionally displaying a building, a current position determining means for determining a current position of the vehicle, building data having two-dimensional coordinates and height information,
Information storage means for storing road data having road attribute information; drawing control means for three-dimensionally drawing a building based on the two-dimensional coordinates and height information stored in the information storage means; Display means for displaying the building drawn by the means, wherein the drawing control means draws by adjusting the height of the building according to the attribute of the road on which the vehicle is currently traveling. Map display device. 7. The drawing control means, when the currently traveling road is a toll road, draws a lower building height than when the vehicle is traveling on a general road. The map display device according to claim 6. 8. A map display program for three-dimensionally displaying a building, wherein the height of the building is adjusted based on building data having two-dimensional coordinates and height information and the height of the current position of the vehicle. A program characterized by drawing.