JP4646720B2 - Navigation device - Google Patents

Description

  The present invention relates to a navigation device mounted on a moving body such as a vehicle, and more particularly to a method for updating a vehicle position when distance information of a self-contained navigation sensor cannot be used.

  The navigation device detects the vehicle position, draws map data around the vehicle position on the display, displays the vehicle mark on the map, and scrolls the map when the vehicle position changes. It has a function to guide the road map. Further, the optimum route to the destination is searched, the searched route is displayed on the display, and the arrival time to the destination by the searched route is also displayed.

  As navigation devices, a self-contained navigation method for calculating the vehicle position from a distance sensor and a direction sensor mounted on the vehicle and a method for calculating the vehicle position by GPS positioning using a satellite have been put into practical use. A distance sensor for self-contained navigation uses, for example, a vehicle speed pulse, and the vehicle speed pulse outputs a pulse signal every time the vehicle travels a certain distance. Further, for example, a gyro sensor is used as the direction sensor. The calculation or update of the vehicle position by the self-contained navigation is calculated by combining the movement distance obtained by the distance sensor and the movement direction vector obtained by the direction sensor.

  In the self-contained navigation, the vehicle position can be calculated with a relatively simple configuration, but since it is a relative position detection, it is difficult to perform highly accurate position measurement. That is, as the vehicle travels, errors accumulate and the accuracy of the vehicle position deteriorates. In order to compensate for this deterioration in accuracy, so-called map matching processing using road (link) data included in the map database is performed. The link data includes the latitude and longitude information of the road, and the vehicle position is calibrated or corrected by collating the vehicle position calculated by the independent navigation with the link data.

  The map matching process is disclosed in Patent Document 1, for example. According to this, in the first map matching method, a travel locus (position and direction for each predetermined travel distance) is stored, a road on the map having the same shape as the travel locus is obtained, and a point on the road is determined. This is a method (pattern matching) for map matching of vehicle position marks. The second map matching method is a method based on a projection method.

  FIG. 8 is an explanatory diagram of map matching by the projection method. The own vehicle position by the self-contained navigation when the own vehicle position is at the point P1 and the vehicle travels by the distance L1 and the relative direction θ1 is defined as P2. At this time, it is a road (link) that can drop a perpendicular from the own vehicle position P2, the angle between the vehicle direction at the own vehicle position P2 and the link is within a certain value, and the link from the own vehicle position P2 to the link Look for a line whose vertical line is within a certain distance. Here, it is assumed that road 1 and road 2 are searched. And the length of the perpendicular dropped from the own vehicle position P2 to the roads 1 and 2 is obtained, and the shorter link is set as a matching candidate. Here, road 1 is assumed. Then, the traveling locus S connecting the own vehicle position P1 and the own vehicle position P2 is translated in the direction of the perpendicular, and the intersection T with the road 1 is obtained, and the traveling locus S is rotated around the intersection T until the road 1 is reached. Then, a map-matched vehicle position P3 is obtained.

  On the other hand, GPS positioning measures the distance of a plurality of GPS satellites orbiting the earth and calculates the vehicle position based on the principle of triangulation. 3D positioning (longitude, latitude, altitude) using 4 satellites for one position measurement, and 2D measuring 2D position (longitude, latitude) using 3 satellites There is positioning. GPS positioning can detect an absolute position, but its accuracy is easily affected by radio wave reception conditions, and accuracy is not always good.

  Patent Document 2 relates to an object tracking system that uses an electronic map and a GPS receiver, and updates the vehicle position to the GPS position when the reliability of accuracy by GPS positioning is high. That is, the GPS receiver receives data from a plurality of satellites and determines the GPS derived position and speed. Based on the previous position of the object, GPS derived position, velocity, DOP, and the continuity of the satellite from which the data was obtained, the system determines whether the GPS data is reliable. If the GPS data is reliable, the previous position of the object is updated to the GPS derived position. The updated position is then matched to the map road.

JP-A-6-337217 Special table 2001-509883

  When the navigation device is attached to the vehicle later, the vehicle speed pulse for self-contained navigation may not be acquired. Also, when moving a river by a ferry or the like with the vehicle engine running, vehicle speed pulses may not be available. In the situation where the vehicle speed pulse cannot be obtained or cannot be used, the self-contained navigation is not possible. Therefore, it is necessary to update the own vehicle position mainly using the information by GPS positioning.

  The positioning accuracy in the open space of GPS positioning is said to be about 10m (2DRMS), but in an environment where there are actually shielding objects and reflection objects, a positioning error of 1km or more may occur in some cases. There is. For this reason, it is possible to compensate for position accuracy by performing map matching using the position on the road database. However, if the GPS error is too large, incorrect map matching is performed and the wrong vehicle position is displayed. And there is a problem of giving wrong guidance.

  The present invention solves the above-described conventional problems, and even when the distance information from the self-contained navigation sensor cannot be used, the navigation apparatus and the vehicle that can accurately calculate the vehicle position based on the GPS positioning information An object is to provide a location update method.

  In the navigation device according to the present invention, when the distance information from the self-contained navigation sensor, for example, when the vehicle speed is pulseless, the amount of change in the GPS position obtained from the GPS positioning information is added to the own vehicle position, thereby gradually increasing. The own vehicle position is updated while suppressing the influence of the GPS error.

  According to the present invention, the navigation device for calculating the vehicle position based on the self-contained navigation sensor and the GPS positioning information and displaying the calculated vehicle position on the road map has a vehicle speed of a certain value or more from the GPS positioning information. In addition, the determination means for determining whether or not the distance information can be used from the self-contained navigation sensor and the distance information of the self-contained navigation sensor cannot be used when the constant time is continued. When it determines, it has the 1st update means which calculates the difference of the last longitude obtained from GPS positioning information, and the current longitude and latitude, and updates the own vehicle position by the said difference.

  Preferably, the navigation apparatus further includes second updating means for map-matching the vehicle position updated by the first updating means to a road on the map data and updating the map-matched road position to the vehicle position. Have In addition, the second updating means may be configured such that when a road candidate satisfying a certain condition is not found, when map matching cannot be performed within a certain time, or when the map matching position is a GPS position based on GPS positioning information. When it is out of the error circle, the vehicle position is updated to the GPS position.

  If the navigation device further determines that the distance information of the autonomous navigation sensor cannot be used, the GPS heading is determined to be the heading of the vehicle when the GPS speed based on the GPS positioning information is equal to or greater than a certain value, and the distance information is less than the certain value. It has direction determining means for setting the direction by the navigation sensor as the own vehicle direction, and display means for displaying the own vehicle position mark on the display according to the own vehicle direction.

  Preferably, the determination unit checks the presence or absence of a vehicle speed pulse after a predetermined time has elapsed since the navigation device is activated, and determines that the distance information of the self-contained navigation sensor cannot be used when there is no vehicle speed pulse. This is to prevent noise from being included in the signal immediately after the start-up, so as not to detect it erroneously.

  The vehicle position update method in the navigation device according to the present invention includes a determination step for determining whether or not the distance information by the self-contained navigation sensor can be used, and GPS positioning when determining that the distance information cannot be used. A first update step for updating the vehicle position based on the change amount of the GPS position based on the information, and map matching the updated vehicle position to a road on the map data, and the map-matched position on the road to the vehicle And a second update step for updating the position.

  According to the present invention, when the distance information from the self-contained navigation sensor cannot be used, the position of the own vehicle is updated by the difference (change amount) in the position information based on the GPS positioning information. The influence of errors due to GPS positioning can be suppressed. Even if the position accuracy based on the GPS positioning information is deteriorated, the position near the correct road becomes the new vehicle position by adding the position change amount based on the GPS positioning information to the map-matched own vehicle position. This increases the probability of map matching to the correct road. Thereby, even in the state where the error due to GPS positioning is large, the occurrence of mismatch is suppressed, and the wrong vehicle position display and wrong guidance are reduced.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an in-vehicle navigation device according to the present invention. As shown in the figure, the navigation device 1 includes a GPS receiver 10 that receives radio waves from a GPS satellite and measures the current position and current direction of the vehicle, a self-contained navigation sensor 12 including a vehicle speed pulse and a gyro sensor, an antenna, and the like. A user input interface 20 including a VICS (Vehicle Information and Communication System) / FM multiplex receiver 16 that receives current road traffic information outside the vehicle via the control panel 14, an operation panel 22, a voice input unit 24, and a remote control operation unit 26, A storage device 30 having a hard disk with a capacity, a data communication control unit 32 that enables wireless or wired data communication, a sound output unit 40 that outputs sound from a speaker 42, a display control unit 50 that displays an image on a display 52, and a program Program memory 60 for storing data, and data for temporarily storing data It contains the data memory 70 and the control unit 80.

  The storage device 30 stores a program and a database for executing various navigation functions. The program includes functions necessary for navigation such as route search to the destination, calculation of estimated arrival time to the destination, route guidance, and the like. The database includes map data, facility data, and the like, and the map data includes road (link) data and intersection data related to roads. Link data is data related to the road connecting the intersections, node data indicating the longitude and latitude of the start and end points of the road, data indicating the type of road (national road, general road, prefectural road, etc.), width, regulation ( For example, it includes data such as one-way traffic) and the number of lanes.

  The data communication control unit 32 may have a built-in communication function or may connect a mobile communication terminal or the like. The data communication control unit 32 is connected to a network such as the Internet, and can acquire information relating to road traffic information and the like from a desired website or server.

  The program memory 60 loads a program stored in the storage device 30. For example, the vehicle speed update program 62 that updates the vehicle position based on the positioning results of the GPS receiver 10 and the self-contained navigation sensor 12, and the vehicle speed that determines whether or not the vehicle speed pulse of the self-contained navigation sensor can be used. A pulseless determination program 64, a program 66 for performing map matching processing, a host vehicle position display program 68 for displaying the host vehicle position on a display, and the like are stored. The data memory 70 includes distance and direction positioning data 72 measured by the GPS receiver 10 and the autonomous navigation sensor 12, map data 74 corresponding to the vehicle position read from the storage device 30, and a route searched route. Data 76 and the like are stored.

  FIG. 2 is a block diagram showing the configuration of the GPS receiver 10. The GPS receiver 10 includes an antenna 102 for receiving radio waves from a GPS satellite, a demodulation unit 104 that amplifies a signal from the antenna 102 and demodulates a baseband signal, and the demodulated signal is specific to the GPS satellite. A despreading unit 106 that multiplies and despreads the PN code to synchronize with the satellite signal, and an arithmetic processing unit 108 that measures the vehicle position and the vehicle direction based on the despread satellite signal. .

  The arithmetic processing unit 108 uses three or four GPS satellites, calculates a pseudo distance from the GPS receiver to the GPS satellite, and detects a two-dimensional or three-dimensional position from the pseudo distance. The arithmetic processing unit 108 calculates the absolute position (latitude, longitude) and azimuth of the own vehicle at intervals of 1 second, and outputs them to the control unit 80.

  Next, the operation of the navigation apparatus of the present embodiment will be described with reference to the flowcharts of FIGS. Here, the description will focus on the update of the own vehicle position. The update of the own vehicle position is executed by the control unit 80 according to the own vehicle position update program 62, the vehicle speed pulseless determination program 64, the map matching processing program 66, etc. stored in the program memory 60 described above.

  When the navigation device is activated (step S101), the vehicle speed pulseless determination program 64 is activated in response thereto (step S102). In accordance with the vehicle speed pulseless determination program 64, the control unit 80 does not determine the vehicle speed pulseless for a certain time (for example, 500 ms) from when the ignition switch is turned on. This is because this period may include ignition noise.

  Moreover, the control part 80 reads the backup data of the own vehicle position memorize | stored in the memory | storage device 30 (step S103). The backup data is the vehicle position and vehicle direction when the use of the navigation device is stopped or when the ignition switch of the vehicle is turned off. This position is the first vehicle position.

  When traveling of the host vehicle is started, the control unit 80 determines whether or not the GPS speed is 50 km / h or more from the positioning by the GPS receiver 10 and the state continues for 5 seconds or more (step) S104). When the state continues, the control unit 80 determines vehicle speed pulseless, that is, determines whether a vehicle speed pulse signal is input from the self-contained navigation sensor during that time (step S105). When there is a vehicle speed pulse signal, the control unit 80 updates the own vehicle position mainly for the self-contained navigation (step S06). In the self-contained navigation, the distance information from the vehicle speed pulse and the direction information vector from the gyro sensor are combined with the current own vehicle position to update the own vehicle position.

  On the other hand, when the vehicle speed pulse signal cannot be obtained, it is determined that the vehicle speed is pulseless (step S107). The vehicle speed pulseless state is when the vehicle speed pulse cannot be used, or when the vehicle is mounted on a ferry or the like and the absolute position moves but the relative position does not move.

  The vehicle speed pulseless state means that it is practically impossible to update the vehicle position by self-contained navigation. Therefore, when it is determined that the vehicle speed is pulseless, the control unit 80 updates the vehicle position using the positioning data obtained by the GPS receiver 10.

  Based on the GPS position from the GPS receiver 10, the controller 80 calculates the difference between the longitude and latitude of the previous GPS position and the current GPS position (step S108). The calculated difference is added to the own vehicle position to update the own vehicle position (step S109). FIG. 4 illustrates an example in which the vehicle position is updated based on the GPS position. Suppose that the current vehicle position is P1 (X1, Y1). Let ΔX and ΔY be the changes in longitude and latitude according to the GPS position. The updated vehicle position P2 (X2, Y2) is a vector composition of the change amounts ΔX, ΔY.

  Next, the control unit 80 determines the orientation of the updated vehicle position P2 (step S110). When the GPS speed is 5 km / h or higher, the GPS direction is the own vehicle direction, and when the GPS speed is less than 5 km / h, the gyro direction is the own vehicle direction. Or if it is a system without a gyro, the previous GPS direction is continued. Since the GPS positioning azimuth has a large error at a low speed, the gyro azimuth is prioritized and the GPS positioning azimuth is adopted at a certain speed or higher.

  Next, the control unit 80 updates the travel distance of the host vehicle with the distance between positioning points by GPS positioning (step S111). The distance between positioning points is substantially equal to the difference in longitude and latitude of GPS positioning, but this distance can be used when distance information is required in the navigation device.

  Next, the control unit 80 performs map matching processing by the projection method for the own vehicle position updated with the change amount of the GPS position (step S112). As shown in FIG. 8 above, the map matching process uses the distance of the vertical line from the own vehicle position to the road (link), the direction of the own vehicle, and the connectivity with the road as parameters and integrates them. Is matched to the road when it satisfies a certain condition.

  When map matching is normally performed (step S113), the vehicle position is updated to the position of the road on the map data subjected to map matching (step S114). On the other hand, when a road that satisfies the conditions for map matching is not found, a road that is a candidate for matching is not found after a certain time (for example, 5 seconds), or the map-matched position is an error circle of the GPS position. When it does not fall within the radius range, the control unit 80 determines that map matching cannot be performed normally (step S113), and updates the vehicle position to the GPS position (step S115).

  The control unit 80 displays the vehicle position mark M on the road R of the display 52 as shown in FIG. 6 according to the vehicle position and direction updated by the map matching (step S116). At this time, the vehicle position mark M is displayed in a direction that matches the traveling direction of the road R according to the GPS direction or the direction of the autonomous navigation sensor.

  FIG. 7 shows an example of the vehicle position update according to this embodiment. In the figure, points P1 to Pn indicated by white circles indicate the vehicle position updated by the GPS position, points Q1 to Qn indicated by x indicate the GPS position, and points S1 to Sn indicated by black circles are map matching. The indicated position is shown.

  The host vehicle position P1 is map-matched on the road R1 and updated to the host vehicle position S1. Then, the change amounts of the GPS positions Q1 and Q2 are added to the own vehicle position S1 and updated to the own vehicle position P2. Next, the host vehicle position P2 is map-matched to the road R1 and updated to the host vehicle position S2. Next, the change in the longitude and latitude of the GPS positions Q2 and Q3 is added to the own vehicle position S2 and updated to the own vehicle position P3, and is updated to the own vehicle position S3 by map matching. In this way, by adding the GPS position difference to the correct vehicle position on the correct road, the vicinity of the correct road becomes the new vehicle position. Since map matching is performed based on this position, the probability of map matching to the correct road increases. As a result, even when the GPS error is large, it is difficult to make a mismatch, and the wrong vehicle position display and wrong guidance are less likely to occur.

  Also, when the GPS position is deteriorated due to the influence of multipaths, obstructions, etc., for example, if the GPS position is separated from the road R1 as Qx, the own vehicle position Px is also separated from the road R1, and the map matching is performed. There is a risk of mismatch with the road R2. If the position Sx map-matched on the road R2 is not within the error circle radius r of the GPS position Qx, it is determined that the matching is not normal, and the own position is corrected to the GPS position Qx. Thereby, the frequency of mismatch can be reduced.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible. In the above embodiment, the operation of updating the vehicle position is controlled by a program. However, the present invention is not necessarily limited to this and may be executed by a hard wafer circuit. Further, the navigation device may be complex with other audio devices and video devices.

  The navigation apparatus according to the present invention can be used in an electronic apparatus such as a navigation apparatus mounted on a vehicle or the like, a navigation system, or a computer including a navigation function.

It is a block diagram which shows the structure of the navigation apparatus which concerns on the Example of this invention. It is a block diagram which shows the structure of a GPS receiver. It is a flowchart explaining operation | movement of the navigation apparatus of a present Example. It is a flowchart explaining operation | movement of the navigation apparatus of a present Example. It is a figure explaining the update of the own vehicle position by a GPS position. It is a figure which shows the example of a display of the own vehicle position mark. It is a figure explaining the example of the own vehicle position update in a present Example. It is a figure explaining the map matching process by the conventional projection method.

Explanation of symbols

1: Navigation device 10: GPS receiver 20: User interface 30: Storage device 40: Audio output unit 50: Display control unit 52: Display 60: Program memory 70: Data memory 80: Control unit

Claims (10)

A navigation device that calculates a vehicle position based on a self-contained navigation sensor and GPS positioning information, and displays the calculated vehicle position on a road map,
A determination means for determining whether or not the distance information is available from the self-contained navigation sensor when the vehicle speed is equal to or greater than a certain value based on the GPS positioning information and continues for a certain time;
If it is determined that the distance information of the self-contained navigation sensor cannot be used, the difference between the previous longitude and latitude obtained from the GPS positioning information is calculated, and the vehicle position is updated with the difference. First updating means;
Map matching the vehicle position updated by the first update means to the road on the map data, and second update means for updating the map-matched position on the road to the vehicle position,
The first update means is a navigation device that updates the vehicle position by adding the difference to the vehicle position updated by map matching . The second update means is a range of GPS position error circles when no road candidate satisfying a certain condition is found, when map matching cannot be performed within a certain time, or when the map matching position is based on GPS positioning information The navigation apparatus according to claim 1 , wherein when the vehicle is outside, the vehicle position is updated to a GPS position based on GPS positioning information. If the navigation device further determines that the distance information of the autonomous navigation sensor cannot be used, the GPS heading is determined to be the heading of the vehicle when the GPS speed based on the GPS positioning information is equal to or greater than a certain value, and the distance information is less than the certain value. has a bearing determining means for the orientation by navigation sensor and the vehicle direction, and display means for displaying a vehicle position mark in accordance with the vehicle direction on the display, a navigation device according to claim 1 or 2. The navigation device further includes distance update means for updating the travel distance of the own vehicle with the distance between the positioning points based on the GPS positioning information when it is determined that the distance information of the self-contained navigation sensor cannot be used. Or the navigation apparatus as described in any one of 3 thru | or 3 . The determination means checks whether or not there is a vehicle speed pulse signal after a lapse of a certain time since the start of the navigation device, and determines that the distance information from the self-contained navigation sensor cannot be used when there is no vehicle speed pulse signal. The navigation device according to any one of 1 to 4 . The navigation device according to any one of claims 1 to 5 , further comprising storage means for storing the vehicle position updated by the first or second update means when use is stopped. A method of updating a vehicle position in a navigation device,
A determination step of determining whether or not the distance information by the self-contained navigation sensor is available when the vehicle speed is equal to or greater than a certain value and continues for a certain time based on the GPS positioning information ;
A first update step of updating the vehicle position with a change amount of the GPS position based on the GPS positioning information when it is determined that the distance information cannot be used;
A second update step of map-matching the updated vehicle position to a road on map data and updating the map-matched position on the road to the vehicle position ;
The first updating step updates the own vehicle position by adding the difference to the own vehicle position updated by map matching . The vehicle position update method further includes a GPS position error based on GPS positioning information when a road candidate satisfying a certain condition is not found, when map matching cannot be performed within a certain period of time, or when the map matching position is based on GPS positioning information. 8. The method for updating a vehicle position according to claim 7 , wherein the vehicle position is updated to a GPS position based on GPS positioning information when the vehicle position is out of a circle. When it is determined that the distance information of the self-contained navigation sensor cannot be used, when the GPS speed based on the GPS positioning information is equal to or greater than a certain value, the GPS azimuth is defined as the own vehicle azimuth. The vehicle position update method according to claim 7 , further comprising: an azimuth determining step for setting the vehicle direction, and a display step for displaying a vehicle position mark on the display in accordance with the vehicle direction. The vehicle position update method further includes a distance update step of updating the travel distance of the vehicle with the distance between the positioning points by GPS positioning when it is determined that the distance information of the self-contained navigation sensor cannot be used. Item 8. The method for updating the vehicle position according to Item 7 .

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