JP3726870B2 - Navigation device and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a navigation apparatus and a recording medium that recognize a current position based on an estimated current position and a GPS position.
[0002]
[Prior art]
In the navigation device, as one of the methods for detecting and tracking the current position, a positioning method for obtaining a position based on a satellite signal using a GPS (Global Positioning System) receiver, and a traveling locus using a gyro sensor and a vehicle speed sensor are used. A method of map matching with the map database is used together with the dead reckoning navigation that is required. At that time, in the case of a road or parking lot where the current position is unregistered, or when there are parallel roads in the traveling road, if you simply perform map matching with the road map and track the current position as before, The wrong road is recognized as the current position. In addition, the current GPS positioning method generally has a positioning error of several tens of meters. Therefore, in order to improve the accuracy of the current position estimation in map matching, for example, in Japanese Patent Laid-Open No. 6-148307, a GPS positioning error is calculated based on GPS accuracy information, and the GPS positioning error is defined as a radius around the GPS positioning position. It has been proposed to estimate the current position from road information within a circle.
[0003]
[Problems to be solved by the invention]
However, in the above proposed technique, the GPS error range is used to narrow down the current position candidates. However, since it depends on the GPS accuracy, if the GPS accuracy is poor and the error range has a large radius, the position on the road More candidates. As a result, there is a high possibility that an incorrect position is selected when determining the position from among the candidates, and there is a problem that a processing load is imposed due to an increase in the number of candidates.
[0004]
[Means for Solving the Problems]
The present invention solves the above-described problems, and appropriately narrows down candidate positions on the road depending on the correlation between the estimated current position and the GPS positioning position, thereby reducing the processing burden. .
[0005]
To this end, the present invention is a navigation device that recognizes the current position based on the estimated current position and the GPS position, and detects a traveling direction and a traveling distance of the vehicle to obtain the estimated current position of the vehicle; a GPS position detecting means for obtaining the GPS location of the vehicle by receiving GPS signals from a satellite, the narrowing of the candidate position on the road in said error circle to set the erroneous difference circle on the basis of the presumed current position and the GPS position And a current position recognizing means for performing the present invention.
[0006]
The current position recognizing means extracts a candidate position on a road based on the estimated current position, determines the presence / absence of a candidate position on the most promising road based on the correlation with the estimated current position, and set the erroneous difference circle depending on the presence or absence of a top candidate positions, to perform the determination of the presence or absence of the dominant road on the candidate position calculating value of the correlation of the candidate position of the highest correlation is based on whether reference values The current position recognizing means corrects the estimated current position when there is a candidate position on the most promising road, and the center between the estimated current position and the GPS position. distance setting a difference circles erroneously as the radius, the present position recognizing means, the corresponding sum corrected distance increment from the previous candidate chromatic located radially at the time of the previous determination in the case of the prime road on the candidate position No Features that you set the make false difference circle It is an.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a navigation device according to the present invention. An input / output device 1 that inputs and outputs information related to route guidance, a current position detection device 2 that detects information related to the current position of the host vehicle, and a route Information storage device 3 storing navigation data necessary for calculation, display guidance data necessary for guidance, etc., central processing unit for performing display guidance processing necessary for route search processing and route guidance and controlling the entire system 4 is configured. First, each configuration will be described.
[0008]
In the following, the map is displayed on the display screen, the destination is entered, the route from the current position to the destination is calculated, and the route is guided to the destination by superimposing the calculated route on the map. The navigation device will be described, but the present invention is not limited to such a navigation device, and the current position and the direction to the destination and the destination are displayed on the map without calculating the route to the destination. Needless to say, the present invention is also applicable to various navigation devices such as a so-called location type that only displays and a type that only displays a traveling direction arrow at an intersection to be turned without displaying a map or a route.
[0009]
The input / output device 1 instructs the central processing device 4 to perform navigation processing according to the driver's intention so that the destination can be input or the driver can output guidance information by voice and / or screen when necessary. It has a function to print out the processed data. As a means for realizing the function, the input unit has a jog dial 11 for inputting a destination by a telephone number or coordinates on a map or requesting route guidance. The jog dial 11 has a dial and an enter key at the center. By rotating, the jog dial 11 moves the cursor and the highlighted selection position on the screen, and determines the selection position by performing an enter operation (pushing). It may be used alone or in combination with other key switches as a wireless remote controller using wired or light. Of course, an input device such as a joystick, a slide bar that slides on a flat surface, a slide pad, or a touch switch may be used as the input unit. Further, the output unit displays the input data on the screen, or automatically displays the route guidance on the screen in response to the driver's request, and is stored in the data processed by the central processing unit 4 or the information storage device 3. A printer 13 for printing out the data and a speaker 16 for outputting the route guidance by voice.
[0010]
Here, a voice recognition device for enabling voice input and a recording card reading device for reading data recorded on an IC card or a magnetic card may be added. In addition, an information center that accumulates data necessary for navigation and is provided via a communication line at the request of the driver, an electronic notebook that stores driver-specific data such as map data and destination data in advance, etc. It is also possible to add a data communication device for exchanging data with other information sources.
[0011]
The display 12 is composed of a color CRT or a color liquid crystal display, and all screens necessary for navigation such as a route setting screen, a section diagram screen, and an intersection diagram screen based on map data and guide data processed by the central processing unit 4 are displayed. Is displayed in color, and a palette for setting route guidance, guidance during route guidance, and screen switching operation is displayed on this screen. In particular, passing intersection information such as passing intersection names is displayed in color in a pop-up on the section diagram screen as needed.
[0012]
The display 12 is provided in an instrument panel in the vicinity of the driver's seat, and the driver can check the current position of the host vehicle by looking at the section diagram, and can obtain information on the future route. Further, when a touch switch is provided on the display 12 corresponding to the display of the function palette, the above operation is performed based on a signal input by touching the palette. The input signal generating means including the pallet and the touch switch constitutes an input unit, but detailed description thereof is omitted here.
[0013]
The current position detection device 2 is a device that detects or receives information related to the current position of the vehicle, and includes an absolute direction sensor 24 composed of a geomagnetic sensor, a relative direction sensor 25 composed of a steering sensor, a gyro, and the like, wheels A distance sensor 26 that detects a travel distance from the number of rotations, a GPS receiver 21 using a satellite navigation system (GPS), and a communication device. The communication device is composed of a VICS (Vehicle Information & Communication System) receiving device 22 and a data transmitting / receiving device 23, which are traffic information acquisition means. The VICS FM multiplexes road traffic information in real time (text broadcasting). ), Radio beacons and optical beacons are transmitted to the vehicle. FM multiplexing transmits rough information over a wide area, and information on radio beacons and optical beacons is detailed in a narrow area within a radius of about 10 km centering on the beacons. Information that can be received when the vehicle passes the beacon. The VICS transmission data is based on the link number assigned to each road, such as the degree of traffic congestion (for example, inaccessibility, congestion, congestion, heavy traffic volume, normal traffic, etc.), traffic jam head position, traffic length, traffic It consists of regulations (construction information, closed roads, etc.) and travel time (time required at a predetermined speed). The data transmitter / receiver 23 is, for example, a mobile phone or a personal computer, and exchanges information necessary for navigation with a traffic information center (for example, ATIS) at the request of the driver.
[0014]
The information storage device 3 is an external storage device that stores a navigation program and data, and is an optical recording medium such as a CD-ROM or DVD-ROM, or a magnetic recording medium such as a flexible disk or MO. The program is composed of a map drawing unit, a route searching unit, a route guiding unit, a current position calculating unit, a destination setting operation control unit, and the like, and includes an application unit and an OS unit that perform navigation signal output processing. Program for processing such as search, display output control necessary for route guidance, program for performing voice output control necessary for voice guidance and data necessary for it, and display information necessary for route guidance and map display Data is stored. The data includes map data necessary for route guidance (road map, house map, building shape map, etc.), intersection data, node data, road data, photo data, registration point data, destination point data, guide road data, It consists of detailed destination data, destination reading data, telephone number data, address data, and other data files and stores all data necessary for the navigation device.
[0015]
The central processing unit 4 stores the CPU 40 that executes various arithmetic processes, and important information (for example, a program that executes route search and route guidance, data that sets conditions, data of various parameters, and the like) in a nonvolatile manner. A flash memory 41 (for example, an electrically erasable and programmable EEPROM) which is a rewritable ROM (rewritable nonvolatile storage means), a program for performing program check and update processing of the flash memory 41 ( Program reading means) Furthermore, the ROM 42 which is a nonvolatile storage means for storing a program for checking the data of the flash memory 41 and the RAM 43 and controlling the information stored therein so as to be rewritable with each other, can be arbitrarily determined by the operation of the driver Register the location information of Information stored by individual, such as memory location, frequency information accumulated by the learning function, error correction information of various detection means, is stored temporarily (volatile), and the stored information is stored even when ACC is turned off. RAM 43 (for example, SRAM which can electrically store temporarily stored information: Static RAM) which is a readable / writable volatile storage means which can be stored, and image data used for screen display on the display are stored. The image memory 44 extracts image data from the image memory 44 based on the display output control signal from the CPU 40, performs image processing, and outputs it to the display. The information storage device 3 based on the audio output control signal from the CPU. Synthesizes speech, phrases, sentences, sounds, etc. read from The voice processor 46 that outputs to the peaker 16, the communication interface 47 that exchanges input / output data by communication, the sensor input interface 48 that takes in the sensor signal of the current position detection device 2, and the date and time are entered in the internal diagnosis information. And a clock 49 for the purpose. In the central processing unit 4, when data acquired by each sensor of the current position detection device 2 is fetched from the sensor input interface 48, the CPU 40 calculates the current position coordinates at regular intervals based on the data, and temporarily Write to RAM 43. The current position coordinates are obtained by performing map matching processing in consideration of detection errors of various data. Further, the output values from various sensors are always corrected. Here, the route guidance is configured so that the driver can select either screen display or voice output.
[0016]
The navigation program and data may be read from the outside via the data transmission / reception device 23. Thus, by reading the necessary navigation program and data from the outside via the data transmitting / receiving device 23, the necessary program and the latest data can be appropriately updated and stored. Alternatively, the information storage device 3 can be omitted and stored directly in the flash memory 41 or the RAM 43 of the central processing unit 4.
[0017]
Next, the operation will be described. FIG. 2 is a diagram for explaining the overall flow of the navigation device according to the present invention, FIG. 3 is a diagram for explaining an example of recognition processing of the current position, and FIG. 4 is a diagram for explaining an example of error circle calculation processing. FIG. 5 is a diagram for explaining a calculation result image of an error circle when there is a current position candidate (there is a candidate on the most prominent road), and FIGS. 6 to 8 are error circles when there is no current position candidate. It is a figure for demonstrating the calculation result image.
[0018]
The outline of the processing executed by the CPU 40 of the central processing unit 4 until the system is started up as a navigation device and point input, route search, route guidance, etc. are performed is as follows. The navigation program is read from the CD-ROM, stored in the flash memory 41, and activated (step S11). Thereafter, for example, a process of acquiring the current position from the current position detection device 2 is performed, and the surrounding map is displayed centering on the current position, and the current position mark, the name of the current position, and the like are displayed (step S12). Next, a process for setting a destination using a telephone number, an address, a facility name, a registered point, etc. is performed (step S13), and a route search from the current position to the destination is performed (step S14). When the route is determined, while displaying the current position by the current position detection device 2, the route guidance display output and voice output processing are performed until the destination is reached (step S15).
[0019]
In the current position recognition process performed in step S12, first, as shown in FIG. 3, the relative position of the vehicle is determined based on the azimuth detected by the relative azimuth sensor 25 in the current position detection device 2 and the travel distance detected by the distance sensor 26. A current position (estimated current position) that is estimated by obtaining a moving amount and a moving direction is determined (step S21), a candidate position on the road is specified (step S22), and whether or not there is a candidate position on the road. A determination is made (step S23). In addition, the candidate position on the road is extended in order from the initial candidate (for example, a leg having a perpendicular line from the estimated position on the road within a predetermined distance from the estimated current position), and if there is a branch, it is extended to each road. What should I do? When there is a candidate position (in the case of YES), the correlation calculation between the candidate position on each road and the estimated current position is performed (step S24), the candidate having the highest correlation is extracted (step S25), and the most It is determined whether or not the correlation of the highly correlated candidate is within the reference value (step S26). Various methods for calculating the correlation between each candidate position on the road and the estimated current position have been proposed (see, for example, Japanese Patent Laid-Open No. 1-41998).
[0020]
When there is no candidate position on the road in the determination of step S23 (in the case of NO), or when the correlation of the candidate having the highest correlation is not within the reference value (in the case of NO) in the determination in step S26. It is determined that there is no candidate on the most prominent road (step S28). However, if the correlation of the candidate having the highest correlation is within the reference value in the determination in step S26 (in the case of YES), the candidate is determined as a candidate on the most promising road (step S27), and the most promising road The estimated position trajectory is corrected based on the upper candidate (step S29). Next, error circle calculation processing is performed (step S30), candidates on the road outside the error circle are deleted (step S31), and the current position is recognized.
[0021]
In the error circle calculation process, as shown in FIG. 4, first, an estimated trajectory obtained using a gyro sensor or a vehicle speed sensor is acquired (step S41), and a GPS trajectory (positioning position) is acquired (step S42). ). Thereafter, it is determined whether or not the acquired GPS trajectory is valid (step S43). If the GPS trajectory is not valid (in the case of NO), the center of the error circle is set as the estimated trajectory point (step S44), and further The reference error circle radius is set to a value obtained by adding 10% of the previous movement distance to the previous reference error circle radius and the movement amount of the GPS trajectory (step S45), and the error circle radius is set to twice this reference error circle radius. (Step S46). The determination of whether or not the GPS trajectory is valid is based on accuracy degradation information transmitted from the satellite, accuracy degradation rate due to the satellite arrangement at the time of position calculation, or the like.
[0022]
If the GPS trajectory is valid (YES) in step S43, the center of the error circle is set to the midpoint between the GPS trajectory point and the estimated trajectory point (step S47), and the current candidate (on the most promising road) It is determined whether or not there is a candidate (step S48). If there is a candidate (in the case of YES), the reference error circle radius is set as the distance between the GPS trajectory point and the estimated trajectory point (step S49). If NO (NO), the reference error circle radius is set to a value obtained by adding 10% of the movement distance from the previous time and the movement amount of the GPS locus to the previous reference error circle radius in the same manner as in step S45 (step S50). Then, an error circle radius is set as the reference error circle radius (step S51).
[0023]
Further, the mountain path is determined based on the radius of the curve, the number thereof, for example, the number of curves between the predetermined distances, and the error circle radius obtained in step S46 or S51 by setting the minimum value of the error circle radius based on the determination value. May be set. This is because a mountain road has many curved roads and has a high probability of causing a position shift at the time of map matching.
[0024]
Next, the above process will be described with reference to FIGS. In the figure, ○ indicates a candidate position locus on the road, Δ indicates an estimated current position locus, × indicates a GPS position locus, O indicates a current candidate position on the road, large Δ indicates a current estimated position, and large × indicates a current position locus The GPS position is shown.
[0025]
For example, as shown in FIG. 5, when a4, b4, and d4 remain as candidate positions on the road (in the case of YES in steps S22 and S23), first, each candidate position of a4, b4, and d4 is estimated. Correlation calculation with the current position S4 is executed (step S24). As a result, it is determined that a4 has the highest correlation and the correlation is within the reference value (steps S25 and S26), so that the estimated current position trajectory is corrected assuming that there is a current position candidate. Therefore, an error circle is set using the midpoint of the estimated current position S4 and the GPS position G4 as the center and the distance between the positions as the radius (steps S30, S47, S49, S51), and the candidate point b4 on the road outside the error circle is selected as a candidate. And move to the calculation at the next estimated current position. (Step S31). That is, the candidates a4 and d4 in the error circle are left and tracked.
[0026]
As shown in FIG. 6, when a5 and d5 remain as candidate positions on the road until the time of the current calculation (in the case of YES in steps S22 and S23), for each point of a5 and d5, the estimated current position S5 When the correlation calculation is executed (step S24), a5 has the highest correlation, but it is determined that the correlation is not within the reference value (steps S25 and S26). Not performed. Therefore, an error circle is set by setting the radius by adding the distance increment from the previous candidate position to the radius at the previous determination, with the center point between the estimated current position S5 and the GPS position G5 as the center (steps S30, S47, S50, S51), the candidate point d5 on the road outside the error circle is deleted from the candidates, and the process proceeds to the calculation at the next estimated current position (step S31). In other words, the candidate a5 in the error circle is left for tracking. Thus, if the estimated current position locus is not corrected (when there is no candidate on the most promising road), the estimated current position is assumed to have low credibility, and a value corresponding to the distance traveled is added to obtain an erroneous calculation circle. In other words, the longer the distance that is not adjusted, the larger the error circle.
[0027]
As shown in FIG. 7, when a6 remains as a candidate position on the road until the current calculation (when YES in steps S22 and S23), the correlation calculation with the estimated current position S6 is executed for the point a6. (Step S24) Since the correlation is determined not to be within the reference value (Steps S25 and S26), the estimated current position trajectory is not corrected as there is no current position candidate. Therefore, with the center point of the estimated current position S6 and the GPS position G6 as the center, the radius at the time of the previous determination is a distance increment from the position with the previous candidate and the GPS pull-in amount, for example, the GPS position and the estimated current position are more than a predetermined distance apart. In this case, the estimated current position is moved or moved to the GPS position. The movement amount of the estimated current position at that time is added to obtain a radius, and an error circle is set (steps S30, S47, S50, S51).
[0028]
Further, when it is determined that there is no GPS position due to reasons such as inability to perform GPS positioning or poor accuracy, as shown in FIG. 8, when a6 remains as a candidate position on the road until the current calculation as shown in FIG. 8 (step S22, In the case of YES in S23, when the correlation calculation with the estimated current position S6 is executed for the point a6 (step S24), it is determined that the correlation is not within the reference value (steps S25 and S26). Assuming that there is no position candidate, the estimated current position locus is not corrected. Therefore, the distance increment from the previous candidate position is added to the radius at the previous determination centered on the estimated current position S6, and further doubled to set the radius as an error circle (steps S30, S40 to S46). For example, if there is a point e6 that falls within the error circle, this point e6 may be newly registered as a candidate point. Here, the point e6 is, for example, a point where a perpendicular is dropped on the road from the estimated current position S6.
[0029]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, a circle is set as the error range. However, it may be set as an ellipse, a rectangle, or other shapes based on the positional relationship between the GPS position and the estimated current position. In the above embodiment, the GPS positioning position and the estimated current position are used as a reference for the error circle. However, not only the GPS positioning position information but also information (correction information) received from D-GPS or the like. You may add it.
[0030]
【The invention's effect】
As is clear from the above description, according to the present invention, the navigation device recognizes the current position based on the estimated current position and the GPS position, and detects the traveling direction and the traveling distance of the vehicle to detect the estimated current position of the vehicle. position and the current position estimating means for determining a GPS position detecting means for obtaining the GPS location of the vehicle by receiving GPS signals from a satellite, in said error circle to set the erroneous difference circle based on the presumed current position and the GPS position Since the present position recognition means for narrowing down the candidate positions on the road is provided, it is possible to narrow down the position candidates on the road within the range of the error circle and reduce the processing load. In addition, the candidate position on the road is extracted based on the estimated current position, and the presence / absence of the candidate position on the most promising road is determined based on the correlation with the estimated current position. By setting, candidate positions on the road can be appropriately narrowed down depending on the correlation between the estimated current position and the GPS position. Furthermore, it is less likely to recognize the current position on the wrong road, such as when driving on a road where there is no parking lot or other data, and as a result, the accuracy of recognizing the current position when returning to the road where the data exists is reduced. Can be improved. Also, since the error circle is set from the correlation between the GPS position and the estimated current position, the error circle automatically increases if any of the accuracy deteriorates due to some influence. The error circle becomes smaller and errors in the current position effective range are reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a navigation device according to the present invention.
FIG. 2 is a diagram for explaining the overall flow of the navigation device according to the present invention.
FIG. 3 is a diagram for explaining an example of current position recognition processing;
FIG. 4 is a diagram for explaining an example of error circle calculation processing;
FIG. 5 is a diagram for explaining a calculation result image of an error circle when there is a current position candidate.
FIG. 6 is a diagram for explaining a calculation result image of an error circle when there is no current position candidate.
FIG. 7 is a diagram for explaining a calculation result image of an error circle when there is no current position candidate.
FIG. 8 is a diagram for explaining a calculation result image of an error circle when there is no current position candidate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input / output device, 2 ... Current position detection device, 3 ... Information storage device, 4 ... Central processing unit, 11 ... Jog dial, 12 ... Display, 13 ... Printer, 16 ... Speaker, 21 ... GPS receiver, 22 ... VICS Receiving device, 23 ... data transmitting / receiving device, 24 ... absolute azimuth sensor, 25 ... relative azimuth sensor, 25 is distance sensor, 40 ... CPU, 41 ... flash memory, 42 ... ROM, 43 ... RAM, 44 ... image memory, 45 ... Image processor 46 ... Audio processor 47 ... Communication interface 48 ... Input interface

Claims (6)

A navigation device that recognizes a current position based on an estimated current position and a GPS position,
A current position estimating means for detecting a traveling direction and a traveling distance of the vehicle to obtain an estimated current position of the vehicle;
GPS position detecting means for receiving a GPS signal from a satellite and obtaining the GPS position of the vehicle;
Navigation apparatus characterized by comprising a current position recognizing means to narrow down the candidate position on the road in said error circle to set the erroneous difference circle on the basis of the presumed current position and the GPS position. The current position recognizing means extracts candidate positions on the road based on the estimated current position and determines the presence / absence of a candidate position on the most promising road based on the correlation with the estimated current position. the navigation system of claim 1, wherein setting the erroneous difference circle depending on whether or not position. The highest correlation of the candidate positions navigation device according to claim 2, characterized in that the determination of the presence or absence of the dominant road on the candidate position calculating values of the correlation property depending on whether reference values of. The current position recognizing means corrects the estimated current position when there is a candidate position on the most promising road, and uses a distance between both positions as a radius centered on a midpoint between the estimated current position and the GPS position. the navigation system of claim 3, wherein setting the erroneous difference circle. The current position recognizing means, and setting means sets the carried erroneous circularly addition correction corresponding to the distance increment from the previous candidate chromatic located radially at the time of the previous determination in the case of the prime road on the candidate position No The navigation device according to claim 3. A recording medium recording a program of a navigation device that recognizes the current position based on the estimated current position and the GPS position, and the estimated current position of the vehicle obtained by detecting the traveling direction and distance of the vehicle and obtained by the current position estimating means record the current position recognition program for narrowing down the candidate position on the road in said error circle to set the erroneous difference circle based on the GPS position of the vehicle obtained by the GPS position detecting means receives a GPS signal from a satellite and A recording medium characterized by that.

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