CN1804552A - Vehicle mounted navigation three-dimensional path display system - Google Patents

Abstract

A vehicle navigation three-dimensional path display system relates to the field of vehicle guidance devices in urban traffic flow guidance systems. Including three-dimensional electronic map dedicated to vehicle guidance; GPS and RD data fusion module capable of receiving GPS satellite positioning signals; computer microprocessor capable of map matching and optimal path calculation; and a display capable of displaying electronic map and guiding path, The GPS and RD data fusion module is connected to the microprocessor, which provides the current position of the vehicle to the microprocessor, and performs matching processing through the microprocessor. The special three-dimensional electronic map for induction is connected to the monitor to display the driving route.

Description

Vehicle navigation three-dimensional path display system

technical field

The invention relates to the field of vehicle-mounted guidance devices in urban traffic flow guidance systems, and is a three-dimensional path display system.

Background technique

At present, foreign experts, scholars and manufacturers are all committed to research, development and production of vehicle navigation devices and similar products. And formed the United States, Japan, Europe as the most representative production bases of several foreign car navigation devices. However, these vehicle-mounted navigation devices use two-dimensional electronic maps to display navigation information, and cannot correctly guide drivers in traffic structures where roads such as overpasses and viaducts have hierarchical structures.

The "vehicle navigation system" with the patent No. 00263679.4 includes a display; a host connected to the display, which also includes a central processing unit for navigation control; a GPS module, which can receive the vehicle orientation data provided by the GPS satellite positioning system, The output is connected to the central processing unit through the interface circuit; an electronic gyroscope, which can provide angular velocity data and GPS module for fusion processing; a storage device for storing map data, the output is connected to the central processing unit, which only provides the display of the driving location when driving. location and other geographic information, and does not provide three-dimensional navigation. The patent number is: CN02812147.3 3D electronic map data generation technology, when generating 3D electronic map data, through the following technology, the 3D modeling of the building can be carried out without measuring the height of the building. Firstly, the building is photographed, and its photographing position and photographing parameters (direction of the camera, angle of view) are recorded. Next, based on these data, the photos are placed in the prepared virtual space in the computer to reproduce the state at the time of shooting. At the same time, the plane shape of the building is configured based on the two-dimensional map data. Again, move the plane shape to the height direction until it coincides with the photo to model the building. Thereby, three-dimensional modeling of buildings can be realized without measuring heights. This patent provides a technology of 3D data collection, but does not provide the steps of data collection, 3D modeling and model optimization of 3D electronic maps cited in the field of vehicle navigation. Patent No.: CN02157183.X "Vehicle Navigation System and Related Software Programs" includes a computer-based control unit with a display unit. Predesignates a set of areas or locations on a given map as on-map targets. Based on the vehicle running condition, it is judged whether or not a predetermined condition with respect to each object on the map, which has been set in advance, is satisfied. The result of this judgment is stored. Based on the judgment information, the user is directly or indirectly notified of the current status of satisfaction/non-satisfaction of predetermined conditions of objects on each map. The patent number is: CN200510063911.X "vehicle navigation system", when the elevated road and the ordinary down road are in the state of stacking, on the display unit of the vehicle navigation system in the target vehicle, the two roads are displayed in the form of overlapping lines. When the target vehicle is traveling on the down road, the elevated road is shown in a transparent state. Therefore, the user of the target vehicle can recognize the state of the down road on which the target vehicle is traveling. On the contrary, when the target vehicle is traveling on the elevated road, the elevated road is shown in a non-transparent state. The elevated road is thus easily visible, so its heading can also be easily seen. This invention adopts transparent and opaque technology to distinguish the hierarchical relationship of viaducts, but on viaducts or overpasses that exceed two floors, this technology is powerless.

With the development of vehicle guidance technology and user needs, the functions of these vehicle navigation devices are too single, and cannot give the driver intuitive and clear route guidance assistance during the actual vehicle driving process.

In short, the planar two-dimensional electronic map guides the route of the vehicle, and there is a shortcoming of unclear route guidance in the complex traffic environment. The reason is that the two-dimensional electronic map adopts the method of vertical projection, and the buildings with original height difference, especially the roads with hierarchical relationship, are all projected on the plane coordinates. From the projection mechanism of the planar map, it can be seen that the planar electronic map cannot intuitively represent the hierarchical structure and height difference of roads.

Technical content:

The present invention aims at the above-mentioned technical problems and shortcomings in the vehicle-mounted navigation process. On the basis of the basic functions of the vehicle-mounted guidance device, three-dimensional data collection, modeling and optimization of complex traffic buildings are carried out, and the realization of the in-vehicle guidance device The display of the 3D scene and the precise positioning of the vehicle in the 3D scene and the display of the induced path and the guidance display.

The invention at least includes a three-dimensional electronic map dedicated to vehicle guidance; a GPS and RD data fusion module capable of receiving GPS satellite positioning signals; a computer microprocessor capable of map matching and optimal path calculation; and capable of displaying the electronic map and guiding the path The display, GPS and RD data fusion module are connected to the microprocessor to provide the current position of the vehicle to the microprocessor for matching processing, and the microprocessor is connected to the special 3D electronic map for vehicle guidance to calculate the optimal path, and the microprocessor The device is connected to the monitor dedicated to the three-dimensional electronic map for vehicle guidance to display the driving route.

Modeling of the map

1. Three-dimensional scene display in the vehicle induction device

The present invention adopts Multigen Vega three-dimensional virtual reality programming software, based on the Vega class library and the Visual C++ programming language, to display the special three-dimensional electronic map for vehicle guidance in the vehicle guidance device.

2. Induce the vehicle positioning in the dedicated 3D electronic map

The present invention adopts GPS and RD fusion positioning technology, comprehensively considers the shortcomings of these two positioning technologies and their complementary effects, and ensures that the positioning error in the three-dimensional electronic map after fusion is less than or equal to three meters.

3. Induce map matching in dedicated 3D electronic maps

The invention adopts the three-dimensional space map matching technology based on space search to ensure the consistency between the display of the vehicle position and the vehicle position in the real environment.

4. Guidance path display and directional arrow display in the three-dimensional electronic map for guidance

Guidance path display and directional arrow display. It can accurately guide the driver to drive in that lane to avoid unnecessary violations.

A control module with a degree of freedom is added to the microprocessor, and the problem of the position of the viewpoint and the direction angle of the line of sight should be solved in the special three-dimensional electronic map for induction. The position of the viewpoint can be input by the driver himself, or can be automatically adjusted to a reasonable position by the program. In principle, the line of sight always falls on the vehicle, and the degrees of freedom control of the induced special 3D electronic map include spatial translation and spatial rotation of the map,

A building transparency module is added to the microprocessor. In the 3D electronic map dedicated to vehicle guidance, no matter how the viewpoint and line of sight are determined, as long as it is not overlooking, high-rise buildings may block the line of sight, causing the vehicle position to not be displayed. Phenomenon.

In the microprocessor, there is a mutual response module of two-dimensional electronic map and three-dimensional electronic map for induction. The best way to deal with the problem that the application of three-dimensional electronic map is easy to cause the driver to lose direction is to combine two-dimensional electronic map and three-dimensional electronic map. up and use. Fang Ming combined the two-dimensional electronic map with the special three-dimensional electronic map for vehicle guidance, and established a mutual response mechanism between the two. Information such as the visible range, and the location searched in the two-dimensional map can be visually displayed in the three-dimensional electronic map dedicated to vehicle guidance.

The present invention collects, models and optimizes the three-dimensional data of complex traffic buildings, and establishes a special three-dimensional electronic map for vehicle guidance, so as to precisely locate the vehicle and guide the optimal route.

Description of drawings:

Fig. 1 is a block diagram of the present invention;

Fig. 2 is the hierarchical structure of the dedicated three-dimensional electronic map model for vehicle guidance;

Fig. 3 is an overall module division diagram of the present invention;

Figure 4 is a design diagram of the GPS/DR fusion module;

Figure 5 is an overall flowchart of GPS/DR fusion positioning;

Fig. 6 is a flowchart of map matching in a three-dimensional electronic map;

Fig. 7 is a flow chart of the degree of freedom control module;

Fig. 8 is a path guidance and arrow display flowchart of a three-dimensional electronic map;

Fig. 9 is a flowchart of building transparency processing module;

Fig. 10 is a flow chart of a mutual response module between a two-dimensional electronic map and a three-dimensional electronic map.

Detailed ways:

The invention mainly includes two parts: the making of the special three-dimensional electronic map for vehicle guidance and the navigation system of the special three-dimensional electronic map for vehicle guidance.

In the actual development process, the 3D electronic map for vehicle guidance should be made first, and the geographical data related to vehicle guidance should be stored in the electronic map. Then, the vehicle 3D navigation software should be developed according to the data structure of the electronic map.

Establishment of 3D electronic map model for vehicle guidance

The establishment process of the special 3D electronic map model for vehicle guidance mainly includes three aspects:

1) Acquisition of 3D geographic information

The present invention adopts the combination of multiple data acquisition technologies, and mainly collects various information related to traffic. Among them, the latitude and longitude information of the three-dimensional electronic map dedicated to vehicle guidance is obtained from the flat two-dimensional electronic map of the same city. The elevation information of the terrain in the three-dimensional map is obtained through aerial photos or two-dimensional topographic map (DEM), and the elevation data of three-dimensional buildings, overpasses and viaducts are obtained through the combination of field measurement and design drawings. The texture information of buildings on both sides of the road is obtained through digital photography and post-processing in PhotoShop.

2) Model construction

Model establishment of the present invention is to adopt Multigen Creator real-time modeling software. The elevation information of the measured terrain is made into a DEM file by MapGIS software. In MultigenCreator, convert the DEM file into a DED file that can be used, and open the DED file for registration. The present invention requires the three-dimensional model to be as simple as possible under the condition of ensuring reality, and there are specific model optimization techniques in the back.

Paste the surface texture according to the latitude and longitude coordinates corresponding to the surface model. Enter Multigen layered according to different feature attributes, select or rebuild the corresponding feature code (FeatureID) and surface material code (SMC), and give it an appropriate texture. Open the building model data Flt in Mulitgen, paste the real texture, and then superimpose it on the landscape. And put trees, flowers and plants in it. Textures include opaque textures and transparent textures, which are used for buildings, roads, trees, grass and other ground objects. Photos (or digitized photos obtained by digital cameras) can be obtained by using close-up settings, and then scanned and digitized, corrected in Photoshop and other image processing software, and stored in TIFF or RGB format as a model texture library. Please refer to Figure 1 for the specific hierarchical structure of the 3D electronic map.

3) Model optimization

Because the cost of the vehicle-mounted induction device cannot be too high and the design space is small, the hardware configuration of the device is relatively low. The special 3D electronic map for inducing itself occupies quite a lot of system resources. Therefore, in the process of 3D modeling, the present invention reduces the complexity of the 3D map by optimizing the map model, and creates conditions for the application of the 3D electronic map in the vehicle environment.

The optimization process of the 3D electronics for vehicle guidance mainly includes:

①LOD technology (distance loading technology)

In the process of 3D modeling, for a 3D model, a complex model, a moderately complex model and a simple model are established respectively. During program design, the program dynamically transfers the above-mentioned complex model, medium complex model and simple model according to the positional relationship between the 3D model and the viewpoint. This technology essentially simulates when the human eye sees an object. The closer to the eye, the clearer the vision, and the farther away from the eye, the blurrier the vision. Please refer to Figure 2 for the specific effect.

②Billboard modeling

Due to the irregular nature of vegetation such as trees, modeling it accurately would result in a large number of curves that make up the model, which would tax the system. The present invention adopts Billboard modeling technology to paste the texture patches of trees on a simple plane rectangular area, and this plane area will always face the viewpoint. In this way, the authenticity of the tree model is guaranteed, and at the same time, the complexity of inducing a special three-dimensional electronic map is reduced.

Three-dimensional electronic map navigation system for vehicle guidance

The present invention adopts the three-dimensional operation class library of Multigen Vega, combined with the Visual C++ programming language, comprehensively considers various factors that affect vehicle positioning and navigation in the three-dimensional electronic map, and designs the vehicle three-dimensional navigation software.

1) Overall design of 3D navigation software

The overall flow of the software is shown in Figure 3, which mainly includes a three-dimensional electronic map module for guidance, a GPS/DR fusion module, a three-dimensional electronic map map matching module, a degree of freedom control module, a three-dimensional path calculation module, a guidance path and a direction arrow display Module design, building transparency module design, two-dimensional electronic map and three-dimensional electronic map mutual response module.

The 3D electronic map database is the core of the entire software operation. The positioning data can only be displayed in the 3D electronic map after being processed by GPS/DR fusion and then through the function of the map matching module. The display of the guidance path requires the path optimization module to provide the optimal path, and then the guidance path can be effectively displayed by matching with the building transparency module.

2) GPS/DR fusion module design

The present invention uses GPS and DR fusion positioning to locate and track dynamic vehicles. There is a strong complementary relationship between the GPS/DR system. On the one hand, the absolute position information provided by GPS can provide DR with the initial value of deduced positioning and perform error correction; Random error. The core problem of realizing the GPS/DR combination is the design of the data fusion scheme. The present invention adopts kalman filtering technology to fuse the GPS/DR data.

As shown in Figure 4, after local filter 1 and local filter 2 filter the positioning information input by GPS and DR respectively, they fuse and generate optimal positioning information through time updating and optimal combination principles for use by vehicle navigation devices .

Figure 5 shows the overall process of GPS/DR fusion positioning. When both GPS and DR data are reliable, the GPS and DR data interact with each other to correct errors and then fuse to generate the best positioning data. When the GPS data is unreliable, use the DR positioning data corrected at the last moment. Send the positioning data to the map matching module, and output it to the map after matching processing.

3) Design of 3D electronic map matching module

Figure 6 shows the map matching process in the 3D electronic map. First, judge whether the vehicle is stopped according to the speed. If it is driving on a road section, search all road sections within 50m of the location point. If no road section is found, the original location data is output on the map; if several road sections are found, the type of road section is judged, and the road section is comprehensively judged according to the driving direction in the input positioning data and the distance from the vehicle to the road section. Then perform projection processing to project the vehicle onto the road segment.

4) Degree of freedom control module design

The degrees of freedom in a three-dimensional electronic map include location information such as longitude, latitude, and altitude, as well as angle information with the three-dimensional coordinate axis of the space. Figure 7 reflects the flow of the degree of freedom control module.

5) Guide path and direction arrow display module design

The path guidance module needs the path calculation module to provide him with the optimal path, and the path guidance module judges the turning situation of the vehicle at a specific intersection according to an optimal path. In the three-dimensional electronic map, the guidance of vehicles on intersections and overpasses needs to be specific to lanes, because the traffic law stipulates that changing lanes at intersections is not allowed, so corresponding prompts must be given before vehicles enter the intersection.

The route calculation in the 3D electronic map generally adopts the same principle as the route calculation in the 2D electronic map, and the calculation results are returned according to the intersection number. The process of path guidance and arrow display on the 3D electronic map is shown in Figure 8. The route guidance module judges the turning conditions of the guiding route at each intersection according to the optimal route information, and then selects the lane corresponding to the turning condition and adds it to the guiding route list, and displays the turning arrow on the lane at the same time.

6) Module design for transparent processing of buildings

The key to building transparency lies in the selection of buildings that block the line of sight. The present invention uses the way of line of sight intersection to judge whether there is a building at an angle to the line of sight between the vehicle's viewpoints, and if so, it will be transparentized. The specific program flow is shown in Figure 9.

The program constantly judges whether the buildings that intersect with the line of sight are transparentized according to the vehicle position and the viewpoint position, and when to cancel the transparent processing.

7) Mutual response module design of 2D electronic map and 3D electronic map

The mutual response between two-dimensional electronic map and three-dimensional electronic map is to realize the mutual operation between two-dimensional and three-dimensional electronic map. For example, the line-of-sight range of the three-dimensional electronic map is displayed on the two-dimensional electronic map, and the buildings searched by the two-dimensional electronic map are displayed on the three-dimensional electronic map. The specific process of this module is shown in Figure 10. The invention extracts the plane angle of view of the three-dimensional electronic map, transforms the coordinates, and projects the plane onto the two-dimensional map. At the same time, the present invention writes the feature IDs of the three-dimensional models in the three-dimensional electronic map into the same names as those in the two-dimensional electronic map, so that the building with the corresponding name in the two-dimensional map can be searched in the three-dimensional map.

Claims (5)

1. A three-dimensional path display system for vehicle navigation, characterized in that: it includes a special three-dimensional electronic map for vehicle guidance; GPS and RD data fusion modules that can receive GPS satellite positioning signals; computer microprocessing that can carry out map matching and optimal path calculation device; and a display that can display the electronic map and guide the route. The GPS and RD data fusion module is connected to the microprocessor to provide the current position of the vehicle to the microprocessor, and the microprocessor is used for matching processing. The three-dimensional electronic map is used to calculate the optimal route, and the microprocessor is connected to the monitor dedicated to the three-dimensional electronic map for vehicle guidance to display the driving route. 2. The three-dimensional path display system for vehicle navigation according to claim 1, characterized in that: there is a degree of freedom control module in the microprocessor, and the degree of freedom includes longitude, latitude and altitude position information, and also includes coordinates with the three-dimensional coordinate axes of space. intersection information. 3. The three-dimensional route display system for vehicle navigation according to claim 1, characterized in that: there is a building transparency processing module in the microprocessor, and the key to building transparency processing lies in the selection of buildings that block the line of sight, using the line of sight intersection point The method determines whether there is a building at an angle to the line of sight between the viewpoints of the vehicle, and if so, makes it transparent; the program continuously judges whether the buildings that intersect with the line of sight are transparentized according to the position of the vehicle and the viewpoint. And when to cancel the transparency process. 4. The vehicle navigation three-dimensional path display system according to claim 1, characterized in that: the GPS and DR fusion module locates and tracks the dynamic vehicle, realizes GPS/DR combination data fusion, and adopts kalman filter to process GPS/DR data Perform fusion. 5. The three-dimensional path display system for vehicle navigation according to claim 1, 4, characterized in that: after the two local filters respectively filter the positioning information input by GPS and DR, the time update and the optimal combination principle are used to Fusion generates optimal positioning information for use by vehicle navigation devices.

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