JP4968580B2 - In-vehicle display device - Google Patents

Description

  The present invention relates to an in-vehicle display device that displays information acquired from a road information transmission source installed on a road.

  As the vehicle travels, the current position is detected by GPS (Global Positioning System), etc., and the current position is displayed on the display together with a road map, and an appropriate route from the starting point to the destination The vehicle-mounted navigation device that guides the user with a display or a voice output device contributes to efficient and safe driving for the user.

  The in-vehicle navigation device has a function of estimating a current position using a technique such as an estimated locus by a sensor such as GPS information, a vehicle speed, a gyro, or a map matching that shows a degree of coincidence between the estimated locus and map data (Patent Literature). 1).

Japanese Patent Laying-Open No. 2005-227092

  However, although the estimated current position has been improved in accuracy with the progress of technology, it has not been able to specify a 100% accurate position. For example, when a road exists in parallel with the road where the estimated current position exists, there may be a current position candidate on the parallel road. When parallel roads are close to each other, it is often difficult to specify which road is the true current position, which is often a cause of erroneous current position determination.

In addition, when receiving information from a VICS (Vehicle Information and Communication System: registered trademark ) beacon, the vehicle-mounted navigation device starts from a point where a beacon transmitter such as an intersection is installed. Some have a function of displaying traffic information. In this case, when the information from the VICS beacon is received and the traffic information at the actual current position is displayed in a state where the actual current position of the vehicle is different from the current position on the map estimated by the map matching, The problem is that it gives a sense of incongruity and confusion.

  Against the background of the above problems, an object of the present invention is to provide an in-vehicle display device that does not give a user a sense of incongruity or confusion by traffic information by a received VICS beacon.

Means for Solving the Problems and Effects of the Invention

An in-vehicle display device for solving the above-described problem stores acquisition means for acquiring pop-up display information about a road from a road information transmission source, position detection means for detecting the current position of the vehicle, and road map data. Map data storage means, display means for displaying road map data on the map display screen, pop-up display means for interrupting and displaying the information for pop-up display on the map display screen, and map display of the vehicle based on the detected current position the current position on the screen, a map matching means for map matching to match the road where the vehicle is estimated to traveling in on a road map, now that displays the current position after the map matching on the map display screen Position display means, map matching accuracy calculation means for calculating the accuracy of map matching, and calculated map match Depending on the grayed accuracy deteriorates, it is assumed that and a pop-up display restriction means for restricting a pop-up display on the display unit.

An object of the present invention is to calculate the map matching accuracy of the current position on the map of the vehicle, and to prevent the user from feeling uncomfortable or confusing by not performing the pop-up display when the accuracy is low. Even if the information from the VICS beacon is received in the state where the actual current position of the vehicle is different from the current position on the map estimated by the map matching, the pop-up display information included in the information is included. Is not displayed, and the problem of giving the user a sense of incongruity or confusion is solved.

  Further, the pop-up display information in the in-vehicle display device of the present invention includes traffic information related to the road related to a predetermined point or section on the road, and the pop-up display means is a point on the road. When the current position of the vehicle arrives in the section, the traffic information is interrupted and displayed on the map display screen as a pop-up display, and the pop-up display restricting means pops up based on the map matching accuracy of the current position for the point or section on the road It can also be configured to limit the display.

  When the point corresponding to the content of the pop-up display information is approached, the traffic information at that point is displayed. However, if the map matching accuracy is poor, the current position of the vehicle and the current position on the map display screen are displayed. In contrast, since the pop-up display regarding a point different from the current position on the map display screen is performed, the user is confused. However, the above configuration restricts pop-up display when the map matching accuracy is poor, so the problem of pop-up display regarding a point different from the current position on the map display screen of the vehicle and confusion of the user is solved. .

  Moreover, the pop-up display information in the in-vehicle display device of the present invention can be configured to be enlarged display information of an intersection.

  One of the pop-up display information useful for the user is the enlarged display information of the intersection. This includes information such as the shape of the intersection, the number of lanes, and where each road at the intersection is going. Even if the intersection information that does not exist in front of the current position on the map display screen of the vehicle is popped up, the user is only confused. However, such a pop-up display is not performed with the above configuration, so that the problem of user confusion is solved.

Further, the current position display means in the in-vehicle display device of the present invention displays the current position before map matching in the area outside the road on the map display screen until the map matching for the current position is completed. The pop-up display restricting means can be configured to prohibit pop-up display when the current position on the map display screen of the vehicle is outside the road.

  When the current position on the map display screen of the vehicle is outside the road, the user who sees it can recognize that the map matching is not accurately performed. If pop-up display is performed in this state, there is a problem that the user has doubts about the accuracy of the map matching function, and the reliability of the in-vehicle display device decreases. However, with the above configuration, pop-up display is prohibited, so that the problem that the user is confused by performing pop-up display regarding a point unrelated to the current position of the vehicle is solved. Further, the reliability of the user with respect to the in-vehicle display device is not lowered.

  Further, the pop-up display limiting means in the in-vehicle display device of the present invention can be configured to prohibit pop-up display when the map matching accuracy is lowered to a predetermined level.

  It may be said that the difference between the current position of the vehicle and the current position on the map display screen increases as the level of map matching accuracy decreases. The relationship between the difference between the two current positions and the level of map matching accuracy can be examined in advance by experiments or the like. With the above configuration, it is possible to decide whether or not to prohibit pop-up display based on simple judgment criteria.

Further, a pop-up display restriction means in the vehicle display device of the present invention, when the current position candidate map-matching accuracy when carrying out the map matching is expected to exceed the predetermined level is only one, a pop-up display It can also be configured to allow.

  This “predetermined level” corresponds to a map matching accuracy such that the difference from the current position on the map display screen is, for example, about several meters. In addition, if there are a plurality of current position candidates exceeding a predetermined level, it must be considered that there is a problem in map matching accuracy. With the above configuration, the pop-up display regarding a point that is highly likely to be unrelated to the current position on the map display screen of the vehicle is not performed, so that the problem that the user is confused is solved.

Further, a pop-up display restriction means in the vehicle display device of the present invention, in addition to the current position of the already displayed by carrying out map matching, exceed the level that the map matching accuracy is predetermined and current position in the display The pop-up display may be prohibited when there is at least one other current position candidate whose difference from the map matching accuracy is within a certain range.

  If there are two current position candidates whose map matching accuracy exceeds a predetermined level, if one of them is close to the maximum value of the map matching accuracy and the other slightly exceeds a predetermined level, both map matching There is a sufficient difference in accuracy, and the former may be the current position on the map display screen. However, if there is no sufficient difference between the two map matching accuracy, it must be considered that there is a problem with the map matching accuracy as described above. In addition, it is possible to examine in advance an experiment or the like to determine the difference between the map matching accuracy between the two and the current position of the vehicle and the current position on the map display screen of the vehicle. The above configuration prohibits pop-up display when there are a plurality of current position candidates with a map matching accuracy exceeding a predetermined level within a certain range, such as “Comparison of Dangri”. The problem of confusion is solved.

Moreover, the vehicle-mounted display apparatus of this invention can also be comprised so that the beacon of the road traffic information communication system installed on the road and transmitting road traffic information in real time may be used as a road information transmission source.

  VICS is an information communication system that transmits road traffic information such as traffic jams and traffic regulations in real time, and displays the road traffic information in characters and figures in an in-vehicle device such as an in-vehicle navigation device. Ten years have passed since VICS started providing information, and the number of users has increased with the spread of in-vehicle devices. With the above configuration, the vehicle-mounted display device of the present invention can be realized at low cost by using existing infrastructure and devices.

  Hereinafter, an example in which the in-vehicle display device of the present invention is configured as a part of the function of the in-vehicle navigation device will be described with reference to the drawings. Of course, it is good also as a structure independent as a vehicle-mounted display apparatus, and it is good also as a structure as a part of other vehicle equipment. FIG. 1 is a block diagram showing the configuration of an in-vehicle navigation device (hereinafter abbreviated as navigation device) 100. The navigation device 100 includes a position detector 1, a map data input device 6, an operation switch group 7, a remote control (hereinafter referred to as remote control) sensor 11, a voice synthesis circuit 24 for performing voice guidance, a speaker 15, a memory 9, and a display. 10, a transceiver 13, a hard disk device (HDD) 21, a LAN (Local Area Network) I / F (interface) 26, a control circuit 8 connected thereto, a remote control terminal 12, and the like.

  The position detector 1 includes a known geomagnetic sensor 2, a gyroscope 3 for detecting the rotational angular velocity of the vehicle 101 (see FIG. 2), a distance sensor 4 for detecting the travel distance of the vehicle 101, and a radio wave from a satellite. A GPS receiver 5 for detecting the position 101 is included. Since these sensors 2, 3, 4, and 5 have errors of different properties, they are configured to be used while being complemented by a plurality of sensors. Depending on the accuracy, some of the above-described sensors may be used, and further, a steering rotation sensor or a wheel sensor of each rolling wheel, such as a vehicle speed sensor 23, may be used. The position detector 1 corresponds to the position detection means of the present invention.

  As the operation switch group 7, for example, a touch panel 22 integrated with the display device 10 or a mechanical switch is used. The touch panel 22 is pressed when an electric circuit is wired on the screen of the display 10 in the X-axis direction and the Y-axis direction through a gap called a spacer on a glass substrate and a transparent film, and the user touches the film. Since the voltage value changes due to short-circuiting of a part of the wiring, a so-called resistance film method for detecting this as a two-dimensional coordinate value (X, Y) is widely used. In addition, a known so-called capacitance method may be used. In addition to the mechanical switch, a pointing device such as a mouse or a cursor may be used. Moreover, a mechanical switch is arrange | positioned at the escutcheon (not shown) which covers the indicator 10 and its periphery, and becomes a design frame, for example.

  It is also possible to input various instructions using the microphone 31 and the voice recognition unit 30. In this method, a voice signal input from the microphone 31 is processed by a voice recognition technique such as a well-known hidden Markov model in the voice recognition unit 30, and converted into an operation command corresponding to the result. Various instructions can be input through the operation switch group 7, the remote control terminal 12, the touch panel 22, and the microphone 31.

  Further, by communicating with the ETC on-vehicle device 17, it is possible to capture the fee information received by the ETC on-vehicle device 17 from the roadside device (not shown) into the navigation device 100. Further, the ETC on-vehicle device 17 may be connected to an external network and communicate with the VICS center 14 or the like.

  The control circuit 8 is configured as a normal computer, and connects a well-known CPU 81, ROM 82, RAM 83, I / O 84 as an input / output circuit, A / D conversion unit 86, drawing unit 87, clock IC 88, and these components. A bus line 85 is provided. The CPU 81 controls the navigation program 21p and data stored in the HDD 21. The CPU 81 controls the reading / writing of data to / from the HDD 21. In addition, a program for performing a minimum necessary operation as the navigation device 100 may be stored in the ROM 82 in a case where the data read / write control from the CPU 81 to the HDD 21 becomes impossible. The control circuit 8 corresponds to the map matching means, map matching accuracy calculation means, and pop-up display restriction means of the present invention.

  The A / D conversion unit 86 includes a well-known A / D (analog / digital) conversion circuit, and converts analog data input from the position detector 1 or the like to the control circuit 8 into digital data that can be calculated by the CPU 81, for example. It is.

  The drawing unit 87 generates display screen data to be displayed on the display unit 10 from map data 21m (described later) stored in the HDD 21 or the like, display data, and display color data.

  The clock IC 88 is also called a real-time clock IC, and sends or sets clock / calendar data in response to a request from the CPU 81. The CPU 81 acquires date / time information from the clock IC 88. Further, date and time information included in the GPS signal received by the GPS receiver 5 may be used. The date information may be generated based on a real-time counter included in the CPU 81. The acquired date / time information is used, for example, for travel history management.

  In addition to the navigation program 21p, the HDD 21 stores so-called map matching data for improving the accuracy of position detection, and map data 21m, which is a map database including road data representing road connections. The map data 21m stores predetermined map image information for display and road network information including link information and node information. The link information is predetermined section information constituting each road, and includes position coordinates, distance, required time, width, number of lanes, speed limit, and the like in the link attributes. The node information is information that defines an intersection (branch road) or the like, and includes position coordinates, the number of right / left turn lanes, a connecting road link, a distance cost, and the like. In addition, data indicating whether or not traffic is possible is set in the inter-link connection information. The map data 21m corresponds to the map data storage means of the present invention.

  In the HDD 21, auxiliary information for route guidance, entertainment information, and other data can be written independently by the user and stored as user data 21u. Data and various information necessary for the operation of the navigation device 100 are also stored as the database 21d.

  The navigation program 21p, map data 21m, user data 21u, and database 21d can be added and updated from the storage medium 20 via the map data input device 6. The storage medium 20 is generally a CD-ROM or DVD based on the amount of data, but may be another medium such as a memory card. Moreover, you may use the structure which downloads data via an external network.

  The memory 9 is composed of a rewritable device such as an EEPROM (Electrically Erasable & Programmable Read Only Memory) or a flash memory, and stores information and data necessary for the operation of the navigation apparatus 100. Has been. The memory 9 holds the stored contents even when the navigation device 100 is turned off. Further, instead of the memory 9, information and data necessary for the operation of the navigation device 100 may be stored in the HDD 21. Further, information and data necessary for the operation of the navigation device 100 may be stored separately in the memory 9 and the HDD 21.

  The display 10 is composed of a known color liquid crystal display, and includes a dot matrix LCD (Liquid Crystal Display) and a driver circuit (not shown) for performing LCD display control. The driver circuit uses, for example, an active matrix driving method in which a transistor is attached to each pixel so that the target pixel can be reliably turned on and off, and a display command sent from the control circuit 8 (drawing unit 87) and Display is performed based on the display screen data. Further, an organic EL (ElectroLuminescence) display or a plasma display may be used as the display 10. The display device 10 corresponds to display means and pop-up display means of the present invention.

  The speaker 15 is connected to a well-known voice synthesis circuit 24, and the digital voice data stored in the memory 9 or the HDD 21 in accordance with a command from the navigation program 21p is converted into analog voice by the voice synthesis circuit 24 and sent out. Note that speech synthesis methods include a recording / editing method in which speech waveforms are stored as they are or after being encoded and connected as necessary, and a text synthesis method in which corresponding speech is synthesized from character input information.

  The transmitter / receiver 13 is provided from the VICS center 14 by an optical beacon or a radio wave beacon that is a VICS beacon output from road transmitters 110 and 111 (see FIG. 2), which are provided along the road, for example. It is a device for receiving road traffic information or FM multiplex broadcasting. Moreover, it is good also as a structure which can be connected to external networks, such as the internet, using the transmitter / receiver 13. FIG. The transceiver 13 corresponds to the acquisition unit of the present invention.

  The vehicle speed sensor 23 includes a rotation detection unit such as a known rotary encoder. For example, the vehicle speed sensor 23 is installed in the vicinity of the wheel mounting unit to detect the rotation of the wheel and send it to the control circuit 8 as a pulse signal. In the control circuit 8, the number of rotations of the wheel is converted into the speed of the vehicle 101 to calculate an expected arrival time from the current position of the vehicle 101 to a predetermined place, or an average vehicle speed for each travel section of the vehicle 101. To do.

  The LAN I / F 26 is an interface circuit for exchanging data with other in-vehicle devices and sensors via the in-vehicle LAN 27. Further, data may be taken from the vehicle speed sensor 23 or connected to the ETC on-vehicle device 17 via the LAN I / F 26.

  With this configuration, when the navigation program 21p is activated by the CPU 81 of the control circuit 8, the navigation device 100 allows the user to operate the operation switch group 7, the touch panel 22, the remote control terminal 12, or the voice from the microphone 31. When a route guidance process for displaying a destination route on the display 10 is selected from a menu (not shown) displayed on the display 10 by input, the following process is performed.

  That is, first, the user searches for a destination. The destination search method includes, for example, a method of specifying an arbitrary point on the map, a method of searching from the area where the destination is located, a method of searching from the telephone number of the destination, and a name of the destination from the Japanese syllabary table There are a method of searching by inputting the number of characters stored in the memory 9 as a facility frequently used by the user. When the destination is set, the current position of the vehicle 101 is obtained by the position detector 1, and a process for obtaining an optimum guide route to the destination from the current position is performed. Then, the guidance route is displayed on the road map on the display 10 so as to guide the user to the appropriate route. As a method for automatically setting an optimum guide route, a method such as the Dijkstra method is known. In addition, at least one of the display 10 and the speaker 15 performs notification of a message according to an operation guidance or an operation state.

  The flow of the pop-up display related process will be described with reference to FIG. This process is included in the navigation program 21p and is repeatedly executed together with other processes of the navigation program 21p. First, a map matching process is executed (S11). Next, a confidence level determination process that is the accuracy of map matching is executed (S12). Next, a pop-up display restriction determination process is executed based on the map matching result and the confidence level (S13). Finally, screen display processing is executed based on the pop-up display restriction determination (S14). In FIG. 3, other processes of the navigation program 21p are omitted.

  The map matching process corresponding to step S11 in FIG. 3 includes, for example, radio navigation that receives radio waves from GPS satellites and calculates the current position (latitude, longitude) of the host vehicle from the received information; By combining the travel distance calculated from the output signal according to the direction calculated from the direction sensor such as the gyro sensor 3 and the self-contained navigation for estimating the current position of the own vehicle, the advantages of both navigations were utilized. A well-known technique for estimating a road on which a vehicle is traveling and for obtaining a more accurate current position of the vehicle by comparing the travel locus of the vehicle calculated from the current position of the vehicle calculated by hybrid navigation with the map data 21m. It is. An example of this map matching processing is described in, for example, Japanese Patent Laid-Open No. 2005-132291 (paragraphs 0058 to 0063).

  The confidence level determination process corresponding to step S12 in FIG. 3 will be described with reference to FIG. First, in S31, the confidence level Z is reset to zero as an initialization process (S31).

Next, the sensor state is determined (S32). In other words, the geomagnetic sensor 2, the gyroscope 3, the distance sensor 4, and the vehicle speed sensor 23 are not malfunctioning such as disconnection or short circuit, and are operating normally, and it is determined whether each sensor can be used. To do. This determination can be made, for example, by observing a change in output from each sensor. If it is determined that all the sensors can be used, the determination result is set to “1”, and a value obtained by assigning a weight of “2 ⁷ ” to the determination result is added to the confidence level Z. On the other hand, if it is determined that any one of the sensors cannot be used, the determination result is “0”. For this reason, the value obtained by assigning weight to the determination result is also zero, and the value of the confidence level Z remains zero.

Next, the positioning status is determined (S33). That is, whether GPS 3D positioning is possible is determined from the number of GPS satellites receiving radio waves and the arrangement of GPS satellites. Normally, if radio waves can be received from four or more GPS satellites, 3D positioning is possible. If it is determined in this step that 3D positioning is possible, the determination result is “1”, and a value obtained by assigning a weight of “2 ⁶ ” to the determination result is added to the confidence level Z. On the other hand, if the radio waves from the number of GPS satellites necessary for 3D positioning are not received, or if the reception is extremely unstable due to the arrangement of the GPS satellites, the determination result is “0”. For this reason, the value obtained by assigning weight to the determination result is also zero, and the value of the confidence level Z is not increased.

Next, the sensor accuracy of the gyroscope 3 and the vehicle speed sensor 23 is determined (S34). Po, Pg, and Pd are standard deviations of the gyro offset error, the gyro gain correction coefficient error, and the distance coefficient error, respectively, and are compared with the experimentally obtained thresholds Po _Th , Pg _Th , and Pd _Th , respectively. In these comparisons, when it is determined that the standard deviations Po, Pg, and Pd of each error are equal to or less than the threshold values Po _Th , Pg _Th , and Pd _Th , the sensor accuracy is considered good. Therefore, the determination result is “1”, and a value obtained by assigning a weight of “2 ⁵ ” to the determination result is added to the confidence level Z. On the other hand, when the standard deviations Po, Pg, Pd of any error exceed the threshold values Po _Th , Pg _Th , Pd _Th , it is considered that the sensor accuracy has deteriorated, so the determination result is set to “0”. For this reason, the value obtained by assigning weight to the determination result is also zero, and the value of the confidence level Z is not increased.

Note that the standard deviations Po, Pg, and Pd of the gyro offset error, the gyro gain correction coefficient error, and the distance coefficient error are the square roots (standards) of the corresponding diagonal components of the Kalman filter system state quantity covariance matrix (posterior estimation value) _Pk. This is a value obtained as a deviation). Details of these values are described in Japanese Patent Application Laid-Open No. 2005-132291 (paragraphs 0050 to 0056).

Next, the absolute value of the relative direction θ (see FIG. 17) between the road link corresponding to the current position obtained in the map matching process and the vehicle direction is compared with the experimentally obtained threshold value θ _Th. Judgment of deviation is performed (S35). When the absolute value of the relative azimuth θ is equal to or less than the threshold value θ _Th , the traveling azimuth of the vehicle approximates the road azimuth, and the vehicle is considered to be traveling on the road. For this reason, the determination result is “1”, and a value obtained by assigning a weight of “2 ⁴ ” to the determination result is added to the confidence level Z. On the other hand, when the absolute value of the relative azimuth θ exceeds the threshold value θ _Th , it is considered that the vehicle is not traveling on the road, so the determination result is “0”. Therefore, in this case, the confidence Z is not increased in the azimuth misalignment determination.

Next, the error range is determined by comparing the standard deviation L of the absolute position error in the vehicle azimuth direction with the experimentally obtained threshold value _LTh (S36). Note that the standard deviation L of the absolute position error in the vehicle azimuth direction is obtained as follows. First, the covariance σ ² _{xx of} the absolute position (longitude direction) error and the covariance σ ² _{yy of the} absolute position (latitude direction) error, which are elements of the system state quantity covariance matrix (posterior estimation value) P _k of the Kalman filter described above The distribution regarding the absolute position error is determined from the covariance σ ² _{xy of} the absolute position (longitude direction) error and the absolute position (latitude direction) error. The standard deviation L of the absolute position error in the vehicle azimuth direction can be obtained from the distribution related to the absolute position error.

On the other hand, when the standard deviation L is less than or equal to the threshold value L _Th , the absolute position error is small, so the determination result is “1”, and the value obtained by assigning a weight of “2 ³ ” to the determination result is the confidence level. Add to Z. On the other hand, when the standard deviation L exceeds the threshold value L _Th , the determination result is “0” because the absolute position error is large. Therefore, in this case, the confidence level Z is not increased in the determination of the error range.

Next, the shape correlation is determined (S37, see FIG. 18). First, the shape correlation coefficient C, which is the average value of the difference between the vehicle direction based on the positioning result and the road direction on the corresponding map data in the section from the current position to the predetermined distance behind, is calculated and obtained experimentally. Compared to the threshold value _CTh . When the shape correlation coefficient C is equal to or less than the threshold value _CTh , there is a high possibility that the vehicle is traveling on the road selected in the map matching process. For this reason, the determination result is “1”, and a value obtained by assigning a weight of “2 ² ” to the determination result is added to the confidence level Z. On the other hand, when the shape correlation coefficient C exceeds the threshold value C _Th , the determination result is set to “0”. Therefore, in this case, the confidence level Z is not increased in the determination of the shape correlation.

Next, the number N of candidate roads belonging to a predetermined search area centered on the current position of the vehicle is obtained and compared with a predetermined threshold number N _Th (S38, see FIG. 19). ). In this determination, if the number N of candidate roads is equal to or less than the threshold number N _Th , the determination result is set to “1” because the possibility that an incorrect road is selected in the map matching process is small. A value assigned with a weight of “2 ¹ ” is added to the confidence level Z. On the other hand, when the number N of candidate roads exceeds the threshold number N _Th , there is a high possibility that an incorrect road will be selected, so the determination result is “0”. Therefore, in this case, the confidence level Z is not increased in determining the number of candidates.

  Next, continuity determination is performed by comparing the magnitude D of the displacement of the vehicle position with a value obtained by multiplying the vehicle speed V at that time by the time dt required for the displacement D (S39, see FIG. 20). As a result of the fitting to the road by the map matching process, the vehicle position may jump greatly. When the magnitude D of the displacement of the vehicle position exceeds a value obtained by multiplying the vehicle speed V and the time dt, it can be considered that such a jump has occurred. In this case, since the road position where the vehicle position is adjusted by the map matching process has changed, the vehicle position specified on the road by the map matching process is considered unstable. On the other hand, when the magnitude D of the displacement of the vehicle position is equal to or less than the value obtained by multiplying the vehicle speed V and the time dt, the vehicle position is continuously adjusted on the same road, and the vehicle position is stable. It is thought that.

Therefore, when the magnitude D of the displacement is equal to or less than the value obtained by multiplying the vehicle speed V and the time dt, the determination result is “1”, and the value obtained by assigning a weight of “2 ⁰ ” to the determination result is set as the confidence level Z. to add. On the other hand, when the magnitude D of the displacement exceeds the value obtained by multiplying the vehicle speed V and the time dt, the determination result is “0”. Therefore, in this case, the confidence level Z is not increased in the determination of continuity.

  Through the processing described above, the confidence level Z becomes a value corresponding to the certainty of the current position of the vehicle detected by the position detector 1 and the certainty of the current position on the map display screen of the vehicle by map matching. Therefore, the confidence level Z can be used as an index that universally indicates the accuracy of the obtained vehicle position.

  As described above, the degree of confidence Z is represented by a numerical value of 0 to 255, but in the following description, a value converted to 0 to 100 is used for convenience.

  The pop-up display restriction determination process corresponding to step S13 in FIG. 3 will be described with reference to FIG. First, the confidence level Z calculated in the confidence level determination process is referred to (S51). Next, when the current position (hereinafter referred to as the estimated current position) on the map display screen of the vehicle obtained by the map matching process (S11 in FIG. 3) is outside the road (S52: Yes), the interrupt display permission flag Is reset (interrupt display disabled state) (S57).

  On the other hand, when the estimated current position is on the road (S52: No), the degree of confidence Z corresponding to the estimated current position is compared with a predetermined value A, and is not equal to or higher than the specified value A (S53: No), the interrupt display permission flag is reset (S57).

  On the other hand, if the degree of confidence Z corresponding to the estimated current position is greater than or equal to the specified value A (S53: Yes), the map matching process checks whether there is a current position candidate that can be the estimated current position in addition to the estimated current position. If it does not exist (S54: No), an interrupt display permission flag is set (interrupt display permission state) (S56).

  On the other hand, when there is a current position candidate other than the estimated current position (S54: Yes), among the current position candidates other than the estimated current position, the degree of confidence (Z) is equal to or greater than the specified value A, and It is checked whether or not there is a difference in confidence level Z that is equal to or less than a predetermined value B (within a certain range). If there is a current position candidate that satisfies this condition (S56: Yes), the interrupt display permission flag is reset (S57).

  On the other hand, if there is no current position candidate that satisfies the above conditions (S56: No), an interrupt display permission flag is set (S56).

  The screen display process corresponding to step S14 in FIG. 3 will be described with reference to FIG. First, when the transmitter / receiver 13 receives a radio wave from the VICS center (S71: Yes), VICS information is acquired (S72).

  If the acquired VICS information includes information for pop-up display (S73: Yes), the current position of the vehicle detected by the position detector 1 is acquired (S74), and the current position is the pop-up acquired above. When approaching the position indicated by the display information within a predetermined distance (S75: Yes), the contents of the interrupt display permission flag set in the above pop-up display restriction determination process are referred to (S76).

  When the interrupt display permission flag is set (S77: Yes), since the interrupt display is permitted, the pop-up display information included in the acquired VICS information is interrupt-displayed on the display screen of the display 10 (S78). .

  An example of interrupt display of pop-up display information on the display screen of the display device 10 will be described with reference to FIGS. FIG. 7 shows that the current position (estimated current position) on the map display screen of the vehicle obtained by map matching is on the road (S52: No in FIG. 5), and the confidence level of the estimated current position is equal to or greater than the specified value A. (S53: Yes in FIG. 5), an interrupt display example of the pop-up display information when there is no current position candidate other than the estimated current position (S54: No in FIG. 5) is shown. In this case, since the estimated current position may be considered to coincide with the current position P of the vehicle detected by the position detector 1, the enlarged display information of the J intersection included in the acquired VICS information is, for example, Pop-up is displayed in the upper left part of the screen.

  As pop-up display information, traffic information such as traffic jam information, detour information, travel time information, and weather information may be included in addition to the enlarged display information of the intersection.

  Assuming that the current position of the vehicle detected by the position detector 1 is P, if the map matching is performed correctly, it should be displayed on the screen as shown in FIG. However, if the estimated current position Q of the vehicle is on the road (S52: No in FIG. 5), but the confidence level of the estimated current position is below the specified value A (S53: No in FIG. 5), Since the current position is P, the VICS information including the enlarged display information of the J intersection is acquired. When approaching the J intersection, the enlarged display information of the J intersection is popped up. However, since the current position is displayed as Q on the display screen as shown in FIG. 8, the enlarged display information of the J intersection is displayed where the user expects the enlarged display information of the K intersection to pop up. Because the information pops up, the user is confused about what information to trust. However, since the interrupt display is prohibited in the configuration of the present invention (S57 in FIG. 5), the pop-up display as shown in FIG. 8 is not performed and the user is not confused.

  An example (S54: Yes in FIG. 5) where the current position candidate (Q, R, S) is present in addition to the estimated current position P is shown in FIG. When the confidence level of each position is as shown in FIG. 11, assuming that the specified value A is 70 as shown in FIG. 15, the confidence level of the estimated current position P is not less than the specified value A (S53 in FIG. 5). Yes) Since the confidence levels of the current position candidates (Q, R, S) are all below the specified value A (S55: No in FIG. 5), the interrupt display is permitted (S56 in FIG. 5), and a pop-up display is performed. .

  Further, when the confidence level of each position is as shown in FIG. 12, if the specified value A is 70 as shown in FIG. 16, the confidence level of the estimated current position P is greater than or equal to the specified value A (FIG. 5). S53: Yes), among the current position candidates (Q, R, S), the difference between the confidence level of Q and R and the confidence level of the estimated current position P is a predetermined value B (in this case 10) Since it is as follows (S55 in FIG. 5: Yes), interrupt display is not permitted (S57 in FIG. 5), and pop-up display is not performed. The same applies when the confidence level of the current position candidate (Q, R, S) exceeds the confidence level of the estimated current position P.

  Further, as shown in FIG. 13, even if there is a current position candidate (Q, R, S) in addition to the estimated current position P, all the degrees of confidence are below the specified value A. When it is determined that the degree of confidence is below the specified value A (S53: Yes in FIG. 5), interrupt display is not permitted (S57 in FIG. 5), and pop-up display is not performed.

  Further, as shown in FIG. 14, even if the estimated current position is only R and the confidence level is equal to or greater than the specified value A, R is out of the road (S52: No in FIG. 5), so interrupt display is not permitted ( In S57 of FIG. 5, the pop-up display is not performed.

  When the interrupt display is prohibited, the fact may be displayed on the display screen of the display 10. For example, when the current position of the vehicle approaches a position indicated by pop-up display information such as an intersection within a predetermined distance (S75: Yes in FIG. 6), an interrupt display permission state (S77: Yes in FIG. 6) If there is, the pop-up display of the intersection is performed as shown in FIG. 7, but when the interrupt display is disabled (S77: No in FIG. 6), the pop-up display screen displays “The accuracy of the current position is not good. A message such as “It cannot be displayed.” Is displayed. Moreover, you may send out from the speaker 15 as a voice message.

The block diagram which shows the structure of a vehicle-mounted navigation apparatus. The figure which shows the example of installation of a road transmitter. The flowchart explaining a pop-up display related process. The flowchart explaining a confidence level determination process. The flowchart explaining a pop-up display restriction | limiting determination process. The flowchart explaining a screen display process. The figure which shows the example of a pop-up display screen at the time of normal. The figure which shows the example of a pop-up display screen which may occur with a prior art, when map matching precision is low. FIG. 9 is a diagram for supplementarily explaining the example of FIG. 8. The figure for demonstrating the example when there exists a present position candidate other than an estimated present position. The figure which shows the example of each confidence degree in case there exists a present position candidate other than an estimated present position. The figure which shows another example of each confidence degree in case there exists a present position candidate other than an estimated present position. The figure which shows another example of each confidence degree in case there exists a present position candidate other than an estimated present position. The figure explaining pop-up display prohibition when the presumed present position is outside a road. The figure which shows the relationship of the confidence level in FIG. The figure which shows the relationship of the confidence level in FIG. The figure explaining the determination of an azimuth | direction deviation. The figure explaining determination of shape correlation. The figure explaining determination of the number of candidates. The figure explaining determination of continuity.

Explanation of symbols

1 Position detector (position detection means)
7 Operation switch group 8 Control circuit (map matching means, map matching accuracy calculation means, pop-up display restriction means)
10 Display (display means, pop-up display means)
12 Remote control terminal 13 Transceiver (Acquisition means)
15 Speaker 21 Hard disk drive (HDD)
21m Map data (map data storage means)
22 Touch Panel 24 Voice Synthesis Circuit 87 Drawing Unit 100 Car Navigation Device 110, 111 Road Transmitter (Road Information Source)

Claims (8)

An acquisition means for acquiring information for pop-up display about a road from a road information transmission source;
Position detecting means for detecting the current position of the vehicle;
Map data storage means for storing road map data;
Display means for displaying the road map data on a map display screen;
Pop-up display means for performing pop- up display for interrupting display of the pop- up display information on the map display screen;
Map matching means for map-matching the current position on the map display screen of the vehicle based on the detected current position so as to match the road estimated to be traveling on the road map;
Current position display means for displaying the current position after the map matching on the map display screen;
Map matching accuracy that calculates the accuracy of the map matching based on the number of candidate roads that belong to a predetermined search area centered on the current position of the vehicle and that are estimated to include the current position of the vehicle A calculation means;
Pop-up display restricting means for restricting the pop-up display in the display means in response to the calculated map matching accuracy getting worse,
Equipped with a,
The pop-up display information includes traffic information related to the road related to a predetermined point or section on the road,
The pop-up display means interrupts and displays the traffic information as the pop-up display information on the map display screen when the current position of the vehicle arrives at the point or the section on the road,
The pop-up display restricting means restricts the pop-up display based on the map matching accuracy of the current position with respect to the point or the section on the road . An acquisition means for acquiring information for pop-up display about a road from a road information transmission source;
Position detecting means for detecting the current position of the vehicle;
Map data storage means for storing road map data;
Display means for displaying the road map data on a map display screen;
Pop-up display means for performing pop- up display for interrupting display of the pop- up display information on the map display screen;
Map matching means for map-matching the current position on the map display screen of the vehicle based on the detected current position so as to match the road estimated to be traveling on the road map;
Current position display means for displaying the current position after the map matching on the map display screen;
Map matching accuracy calculating means for calculating the accuracy of the map matching;
Pop-up display restricting means for restricting the pop-up display in the display means in response to the calculated map matching accuracy getting worse,
With
The pop-up display information includes traffic information related to the road related to a predetermined point or section on the road,
The pop-up display means interrupts and displays the traffic information as the pop-up display information on the map display screen when the current position of the vehicle arrives at the point or the section on the road,
The pop-up display restricting means restricts the pop-up display based on the map matching accuracy of the current position with respect to the point or the section on the road . The in-vehicle display device according to claim 1 , wherein the pop-up display information is enlarged display information of an intersection . The current position display means is for displaying the current position before map matching in an area outside the road on the map display screen until the map matching for the current position is completed,
The in-vehicle display according to any one of claims 1 to 3, wherein the pop-up display restriction unit prohibits the pop-up display when a current position of the vehicle on the map display screen is outside a road. apparatus. The in-vehicle display device according to any one of claims 1 to 4, wherein the pop-up display restriction unit prohibits the pop-up display when the map matching accuracy is lowered to a predetermined level . The pop-up display restriction unit permits the pop-up display when the map matching is performed and the map matching accuracy is predicted to exceed a predetermined level when there is only one current position candidate. The in-vehicle display device according to claim 5. The pop-up display restricting means performs the map matching and, in addition to the current position that is already displayed, the map matching accuracy exceeds a predetermined level, and the map matching accuracy of the current position that is being displayed. The in-vehicle display device according to claim 6, wherein the pop-up display is prohibited when at least one other current position candidate having a difference within a certain range exists . The in-vehicle display device according to any one of claims 1 to 7, wherein a beacon of a road traffic information communication system installed on a road and transmitting road traffic information is used as the road information transmission source .

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