JP2716838B2 - Car navigation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention takes in various external information based on a high-precision vehicle position detection method, selects necessary data, and outputs it to a monitor or voice. And a car navigation system for teaching a driver.

(Prior art) Conventionally, the vehicle position detection method of this type of system includes:
There has been an estimating steering method for calculating the current position based on the detection amounts of the distance sensor and the direction sensor, but there has been a problem that errors of each sensor are accumulated.

For this reason, as shown in FIG. 6, the current position is calculated by the estimated position calculation unit 3 based on the detection amounts of the distance sensor 1 and the direction sensor 2, and the comparison correction unit 4 stores the data and the data in the map storage device 5. A so-called map matching method has been proposed in which the calculated position is compared with the map data, and if the calculated position is shifted from the road in the map, the shift amount is corrected and converted to a position on the road (US Pat. No. 3,789,198). Specification, JP-A-58-99715, JP-A-58-113711, and LANDFALL A HIGH-RESOLUTION AUTOMATIC VEHICLE
-LOCATION SYSTEM and JP-A-63-148115).

Specifically, in the position detection method described in U.S. Pat. No. 3,789,198, the estimated position obtained from the output data of the distance sensor and the direction sensor is
The current position data is corrected if the value is within a certain value from the map road position stored in the memory, and if the value is more than a certain value, no correction is made.

In JP-A-58-99715, as shown in FIG.
Each time the vehicle travels a predetermined distance, the coordinate system is converted into the coordinate system of the saved map data. When the vehicle deviates from the road in the map, the position is corrected on the nearest road.

LANDFALL A HIGH-RESOLUTION AUTOMATIC VEHICLE-L
In the position detection method described in OCATION SYSTEM, the road traffic network is classified into a non-branch part and a plurality of branch parts, and when entering a certain branch point, the direction sensor next determines which direction the branch exited. On the other hand, the distance to the next branch point is detected by a distance sensor.

Japanese Patent Application Laid-Open No. 63-148115 discloses a map for determining which one of roads on a map stored in a memory is present on current position data obtained by obtaining a travel distance and an azimuth change amount at each predetermined timing. In the matching method,
Register all the roads located within the error of the sensor detection data centering on the estimated position, set a correlation coefficient corresponding to the amount of error with the estimated position on each road, and estimate the on-road estimated position with the highest correlation coefficient Are displayed on the monitor, and the roads having a correlation coefficient equal to or less than a certain value in the map matching traveling process are deleted from the registration.

(Problems to be Solved by the Invention) However, in any of the above position detection methods,
Since the accumulated errors of the distance sensor and the direction sensor are large, if the current position is corrected simply on a nearby road, the traveling display on a completely different road results. Further, even when the road selection is determined while obtaining the priority with the probability of each section, the error once generated cannot be eliminated thereafter.

The present invention has been made in view of the above problems, and has as its object to provide a car navigation system capable of minimizing the accumulated error of a distance sensor and an azimuth sensor and performing accurate traveling display.

[Means for Solving the Problems] To solve the above problems, the invention according to claim 1 includes a distance sensor for detecting a traveling distance of a vehicle, and a traveling azimuth at a traveling position of the vehicle. Direction sensor, traveling distance detected by the distance sensor, and traveling position / direction retaining means for retaining a traveling direction at each traveling position detected by the direction sensor for a predetermined traveling distance section, and map data on roads. Map data storage means for storing, and dividing the travel distance section into a plurality of sections,
Route selection for selecting a route that overlaps a road on the map stored by the map data storage means by stepwise increasing or decreasing the travel distance of each divided section and the travel azimuth of the divided position held by the direction storage means in a small amount. Means, and display means for displaying the route selected by the route selecting means in combination with the map data stored by the map data storing means.

According to a second aspect of the present invention, in the first aspect of the present invention, a small increase / decrease value holding unit holds a small increase / decrease value of a traveling distance of each divided section and a traveling azimuth of a divided position used for the route selection by the route selecting means. Means, and the route selecting means performs stepwise minute increase / decrease of the traveling distance of each divided section and the traveling azimuth of the division position by preferentially using the minute increase / decrease value held by the minute increase / decrease value holding means. Things.

According to a third aspect of the present invention, there is provided a distance sensor for detecting a traveling distance of a vehicle, an azimuth sensor for detecting a traveling azimuth of the vehicle, and determining the detected traveling distance and a traveling azimuth at each traveling position in a predetermined traveling distance section. Travel position / azimuth holding means for storing minute data, map data storage means for storing map data relating to roads, current position holding means for storing one or more current positions on the map data, and a starting point for the current position. Route selection means for selecting one or more routes on the map road stored by the map data storage means from the correlation between the map data and the travel distance and travel direction for the predetermined travel distance section Display means for combining and displaying the route selected by the route selection means with the map data stored by the map data storage means; Rewriting means for rewriting the current position held by the location holding means to the end of the route selected by the route selecting means; and a map in which the route selected by the route selecting means is stored by the map data storing means. And an erasing means for erasing the corresponding current position retroactively from the current position holding means when deviating from the road by a predetermined amount or more.

According to a fourth aspect of the present invention, there is provided a distance sensor for detecting a traveling distance of a vehicle, an azimuth sensor for detecting a traveling azimuth of the vehicle, and determining the detected traveling distance and the traveling azimuth at each traveling position in a predetermined traveling distance section. Travel position / direction holding means for holding minutes, planned route input means for sequentially inputting a planned route from the departure point to the destination point for each branch point of the road,
Map data storage means for storing map data relating to roads; map data stored in the map data storage means for road data corresponding to the planned route input by the planned route input means and the course direction change angle at the branch point The map data storage unit calculates the map data from the correlation between the map data and the travel distance and travel direction for the predetermined travel distance section while preferentially using the calculation result by the planned route calculation unit calculated from the data. Route selection means for selecting a route on a road in the map stored by the means; and display means for displaying the route selected by the route selection means in combination with the map data stored by the map data storage means. It is provided.

According to a fifth aspect of the present invention, in the car navigation system according to the fourth aspect, a means for determining whether a route selected by the route selecting means deviates from a result calculated by the scheduled route calculating means by a predetermined amount or more; Means for notifying the user when it is determined that the

According to a sixth aspect of the present invention, in the car navigation system according to the fourth aspect, a route selection data holding unit that holds data used for selecting a route by the route selection unit, and the route selected by the route selection unit is Position calculation means for calculating a current position based on data held in the route selection data holding means, when the calculation result by the planned route calculation means deviates by a predetermined amount or more or when there is no route selected by the route selection means, Means for characteristically displaying the calculated current position on the display means.

According to a seventh aspect of the present invention, there is provided a distance sensor for detecting a traveling distance of a vehicle, an azimuth sensor for detecting a traveling azimuth of the vehicle, and the detected traveling distance and a traveling azimuth at each traveling position in a predetermined traveling distance section. Travel position / direction holding means for storing the map data, map data storage means for storing map data related to the road, and the map data storage based on the correlation between the travel distance and travel direction for the predetermined travel distance section and the map data. Means for selecting a route on the road in the map stored by the means, planned route input means for sequentially inputting a planned route from the departure point to the destination point for each branch point of the road, and the planned route input means. The road data corresponding to the input planned route and the course direction change angle at the junction are calculated from the map data stored in the map data storage means. Road calculating means, and first determining means for determining whether the vehicle has reached a predetermined distance before the branch point based on a comparison between the result calculated by the scheduled path calculating means and the path selected by the path selecting means; When it is determined by the first determining means that the vehicle has reached a predetermined distance before the branch point, a right / left determination is made based on the course direction change angle at the branch point calculated by the planned route calculating means. It comprises a second judging means and a notifying means for notifying a result of the judgment by the second judging means.

The invention according to claim 8 is the invention according to claim 4 or claim 7.
In the car navigation system described above, means for checking whether there is a branch point that has not been input between the start point and the end point of the planned route input by the planned route input means, and when there is a branch point that has not been input And means for notifying that effect.

According to a ninth aspect of the present invention, in the car navigation system according to the first, third, fourth, or seventh aspect, the distance sensor controls the rotation speed of the driven left and right wheels by four-wheel drive. Alternatively, in the case of a vehicle equipped with an anti-lock brake system, the number of rotations of all wheels is detected, and each traveling distance is calculated from the tire diameter of an external input, and then averaged.

According to a tenth aspect of the present invention, in the car navigation system according to the ninth aspect, an ultrasonic transceiver is provided on an axle provided with a wheel rotation detector which is a component of the distance sensor, and the ultrasonic transceiver has an ultrasonic transceiver. It comprises means for measuring the time required for reflection of the output from the road surface, and means for calculating the effective tire diameter from the wheel rotation center to the road surface based on the measured time.

According to an eleventh aspect of the present invention, in the car navigation system according to the first, third, fourth, or seventh aspect, the azimuth sensor has a center axis held perpendicular to a vehicle body floor. Rotating body with inertia
A torque generating means for driving the rotating body; and a pulse generating means for generating a predetermined pulse according to the rotation of the rotating body, wherein the pulse generating means is provided when the output of the distance sensor is "0". The number of pulses per unit time is counted, and the average pulse cycle is stored. When the output of the distance sensor is other than "0", the pulse generation means generates the pulse based on the stored average pulse cycle. By detecting the phase difference with the pulse to be changed, the angle is converted into the vehicle body direction change angle.

According to a twelfth aspect of the present invention, in the car navigation system according to the eleventh aspect, a heating unit that heats the torque generating unit, a temperature measuring unit that measures a temperature of the torque generating unit, and a measurement result obtained by the temperature measuring unit. And control means for controlling the heating means so that the torque generating means has a constant temperature based on

The invention according to claim 13 is the invention according to claim 4 or claim 7.
In the car navigation system described above, data on a planned route from a departure point to a destination input by the planned route input unit or data on a planned route calculated by the planned route calculation unit is stored in a portable recording medium. It can be played.

According to a fourteenth aspect of the present invention, in the car navigation system according to the first, third, fourth, or seventh aspect, a portable recording medium storing character data or still image data is reproduced. It is made possible.

The invention according to claim 15 is the invention according to claim 4 or claim 7.
In the car navigation system according to the description, a video camera directed to the rear of the vehicle, means for recording and reproducing a video output signal from the video camera, and means for recording a still image with the video camera for each right and left turn during forward traveling Means for reproducing the still image at a predetermined distance before each left / right turn when traveling backward.

The invention according to claim 16 is the car navigation system according to claim 15, wherein first detection means for detecting that the vehicle has arrived before the junction based on the scheduled route input by the scheduled route input means, Second detecting means for detecting a time point at which the output value of the azimuth sensor decreases after a large change.
When it is detected that the vehicle has arrived just before the junction by the detecting means, the video camera records a still image,
During the return traveling, the still image is reproduced after the first detecting means detects that the vehicle has reached a point just before the branch point.

According to a seventeenth aspect of the present invention, in the car navigation system according to the fourth aspect, receiving means for receiving a radio wave transmitted from an external transmitter, and data received by the receiving means and input by the scheduled route input means. Determining means for determining whether the received data is data related to the scheduled route by comparing the received data with the data related to the scheduled route; and determining whether the received data is data related to the scheduled route. Storage means for storing the data stored in the storage means, and when the data stored in the storage means is related to the map data displayed in the display means, the data stored in the storage means is combined with the map data to display the data. And means for displaying the information.

According to the invention of claim 18, in the car navigation system according to claim 2, when at least two fixed position inputs are made in the passage route section, the azimuth change angle total is calculated from the map data for the route between these two points. First calculating means for calculating the total number of distances, a second calculating means for calculating the sum of output data of the azimuth sensor and the distance sensor, and a calculation result obtained by the first calculating means and the second calculating means. Correction means for correcting the value held by the minute increase / decrease value holding means based on a comparison with the calculation result by the calculation means.

The invention according to claim 19, in the car navigation system according to claim 18, receiving means for receiving the radio wave of the current position data transmitted from the transmitter installed on the roadside, the received current position data Conversion means for converting the map data into a coordinate system, wherein the converted current position data is inputted as a fixed position in the first calculation means and displayed as the current position on the display means.

According to a twentieth aspect of the invention, in the car navigation system according to the first, third, fourth, or seventh aspect, a unique radio wave emitted from several satellites is used instead of the distance sensor and the direction sensor. Means for converting the output data of the global positioning system for obtaining the current position of the vehicle into the coordinate system of the map data, and a linear movement distance from the converted output data of two adjacent points obtained at predetermined time intervals. This is an apparatus comprising a means for obtaining a progress change angle.

(Operation) In the present invention, a position matching can be performed with high accuracy because a map matching method based on detection errors of the azimuth sensor and the distance sensor is employed, and the accumulated error of the sensors is small.

In addition, by inputting the planned route in advance, the sensor detection amount correction value can be promptly obtained by the preferential pattern matching effect between the estimated route calculated by the sensor output data and the planned route, and before the branching approach. Direction of turning right and left can be easily indicated.

Further, in the future, when the social support infrastructure is established, for example, when the current position is received by radio waves from a sign post or the like, it is captured as accurate position data, and the correlation between the sensor output data up to that time and the map data is taken. In addition, the sensor detection amount correction value is obtained, and the accumulated error, which is a weak point of the estimating steering method, can be suppressed as much as possible.

In addition, when using a GPS receiver that outputs vehicle position data using a signal emitted from a satellite, even if an error occurs due to the effects of reception sensitivity and multipath etc. in Tokyo or mountain roads, it is detected. An appropriate map road is selected by obtaining a direction change angle and a distance change amount from data between two adjacent points and inputting them to the pattern matching of the present system.

In addition, the IC card is stored in
By using a card or magnetic floppy, when the same route is used, the previous scheduled route information can be used, and lending to another person becomes possible.

It should be noted that driving can be assisted by reproducing a still image, map data, parking guidance, and the like as a recorded route guide on an in-vehicle monitor.

Also, by connecting an in-vehicle rear surveillance camera to this large-capacity memory device, it is possible to record a landscape image near the branch point on the outbound route, play back the landscape image on the return trip, and mark it as a right or left turn mark The scalability of the system is fully considered.

(Example) Hereinafter, details of an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a car navigation system according to one embodiment of the present invention.

As shown in FIG. 1, the car navigation system of this embodiment includes a traveling distance / direction detecting unit 10 for detecting a traveling distance and a traveling direction of a vehicle, and a position estimating unit 20 for estimating a current position of the vehicle. The main part is configured by a pre-passage route registration unit 30 that pre-registers the pass-through route of the vehicle and the like.

 First, the traveling distance / direction detection unit 10 will be described.

In a running distance / direction detecting unit 10 shown in FIG. 1, a running distance sensor 11 detects a running distance of a vehicle on which the system is mounted, a running direction sensor 12 detects a running direction of the vehicle, and a running direction 13 This is a traveling distance sensor output memory that stores data detected by the distance sensor 11 at predetermined time intervals Δt.

Reference numeral 14 denotes a traveling azimuth sensor output memory for storing data detected by the traveling azimuth sensor 12 at a predetermined time interval Δt, and reference numeral 15 denotes a cumulative total of the traveling distances of the data stored by the traveling distance sensor output memory 13 and the value thereof. Is a section setting section that outputs a predetermined operation start signal when the vehicle reaches a predetermined traveling distance ΣΔLi.

Each data detected by the traveling distance sensor 11 and the traveling direction sensor 12 is stored in the traveling distance sensor output memory 13 and the traveling direction sensor output memory 14 at predetermined time intervals Δt.
Is stored in Here, when the traveling distance stored by the traveling distance sensor output memory 13 reaches the traveling distance ΣΔLi,
An operation start signal is output from the section setting unit 15 to the position estimating unit 20, and data stored in the traveling distance sensor output memory 13 and the traveling azimuth sensor output memory 14 are sent to the position estimating unit 20.

 Next, the position estimating unit 20 will be described.

In the position estimating unit 20 shown in FIG. 1, when the operation start signal is input, 21 is based on the data sent from the traveling distance sensor output memory 13 and the traveling azimuth sensor output memory 14 and the value of the sensor correction memory unit 22. A section estimation route calculator for converting a passing route into a point sequence in a display map coordinate system (for example, east-west: X axis, north-south: Y-axis), 23 is a point sequence data converted by the section estimation route calculator 21 and a map storage device A section end position (next section start position) calculation unit for performing comparison matching with the stored map data stored in 41.

24 is a section end position (next section start position) calculation section 23
A sensor correction range checker for checking whether the correction amount α of each azimuth detection data and the correction amount β of the mileage detection data when each point sequence data is corrected by the comparison matching in a predetermined allowable range. , 22 are sensor correction memory units that hold the data of the correction amount α and the correction amount β when the sensor correction range check unit 24 determines that they are within the allowable range.

Further, 25 is a section end position (next section start position) calculation section 23
Is a current (final) position memory unit for holding data on the section end position Pn obtained by the above, and 26 is a passage route memory unit for holding data on similarly obtained route coordinate positions P1, P2,..., Pn. The data on the section end position Pn stored in the current (final) position memory unit 25 is used as the initial position data of the next section in the section estimated route calculation unit 21. When there are a plurality of section end positions Pn, each data is stored in the current (final) position memory unit.
, Pn, and the data relating to each of the route coordinate positions P1, P2,. Then, the data relating to each section final position Pn is used as initial position data of the next section in the section estimation route calculation unit 21. That is, when there are a plurality of pieces of data related to the section end position Pn, the section estimation path calculation unit 21 estimates a plurality of paths in the next section.

Next, the operation of the above-described comparison matching will be described with reference to FIG.

First, point sequence data obtained by converting the passing route into the display map coordinate system is transmitted from the section estimation route calculation unit 21 to the section end position (next section start position) calculation unit 23.

Then, the section end position (next section start position) calculation section 23
First, as shown in FIG. 2 (a), the initial input position (or the last position of the previous section) P0 is positioned on the map road on the map. In FIG. 2 (a), ΔL1, ΔL
.. Indicate the traveling distances between adjacent route coordinate positions P1, P2,..., Pn, and θ1, θ2.

Next, θ1, θ2,... And ΔL1, ΔL2,... Are changed stepwise so that the route coordinate positions P1, P2,. For example, as shown in FIG.
2 are slightly increased, and ΔL1, ΔL2,... Are slightly increased, and θ1, θ2,. However, the correction amount α of the azimuth detection data and the correction amount β of the traveling distance detection data are changed stepwise around the value of the sensor correction memory unit 22 within a predetermined allowable range.

And, by such a gradual change, P1, P2,
.., Pn selects the route that overlaps the map road most, and obtains the section final position Pn (Xn, Yn) on the map road.

That is, the Pn coordinates are Is required.

 Here, (X0, Y0): the start point P0 coordinate of the section, ΔLi: the output value of the traveling distance sensor between Pi-1 to Pi, and Δθi: the output value of the traveling direction sensor between Pi-1 to Pi.

In addition, since the approximate course direction is set only at the first time of performing such alignment, the estimated route needs to be rotated about P0. Alternatively, the correction value of each sensor may be initially set by inputting the determined position data of the two points and reversing the above operation.

Further, if the route to be passed is registered and the route is significantly deviated from the comparison target route and exceeds the sensor allowable limit value due to a failure of the traveling distance sensor 11 or the traveling direction sensor 12, the sensor correction range checking unit 24 , This data is detected, and the corresponding data stored in the current (final) position memory unit 25 is deleted retroactively.

Therefore, the map matching of the present system is performed by the section estimation route calculation section 21 → section end position (next section start position) calculation section
23 → Sensor correction range check unit 24 → Sensor correction memory unit
22 → By repeating the loop of the section estimation route calculation unit 21,
The section end position Pn has been obtained.

The data on the section end position Pn obtained in this manner is stored in the current (final) position memory unit 25, and is used as the initial position data of the next section in the section estimation route calculation unit 21. Data on the route coordinate positions P1, P2,..., Pn is stored in the passage route memory unit 26.

Then, the data stored in the passage route memory unit 26 is
The image data is temporarily stored in the image data memory 42.

The image data memory 42 combines the stored map data stored in the map storage device 41 with the data stored in the passage route memory 26, and displays the composite image on the monitor 43.

 Next, the pre-passage route registration unit 30 will be described.

The registration of the pre-passage route is performed by designating an arbitrary start point to an end point on the map displayed on the monitor 43 for each route change point (branch point) by operating the operation unit 44. Specifically, this is performed by moving the cursor on each route change point in order from the starting point and pressing a predetermined key.

Here, reference numeral 31 denotes a scheduled route input check unit for checking the continuity of the traffic route input by the operation unit 44 by comparing the input by the operation unit 44 described above with the saved map data stored in the map storage device 41. . Checking the continuity of a traffic route refers to checking whether there is a branch point that has not been instructed between the start point and the end point of the input traffic route.For example, the end point is the start point of the next use route. This is done by confirming that Further, the scheduled route input check unit 31 calculates the input road data of the road from the start point to the end point and the branch points and the traveling direction change angles at the branch points based on the stored map data stored in the map storage device 41. calculate.

Reference numeral 32 denotes a planned route line memory unit that stores the road data calculated by the planned route input check unit 31, the branch points thereof, and the course direction change angles at the branch points. The road data and the like can be written in the image data memory unit 42 in different colors or the like.

Further, 33 is based on a comparison between the data of the passage route memory unit 26 and the data of the planned route route memory 32 and determines on which route the current route is to reach the next branch point and how many kilometers to reach the next branch point. Is a next branch point approach azimuth calculation unit for determining whether the vehicle is turning right or left.

If an incorrect input is made at the time of registration of the pre-passing route, this is detected by the scheduled route input checking unit 31, and a comment is displayed on the monitor 43 as an instruction error, or a voice or information sound is output from the speaker 46. Is output.

On the other hand, when a correct input is made, the road data calculated by the planned route input check unit 31 and the branch points and the course direction change angles at the branch points are stored in the planned route route memory unit 32.

Also, the next branch point approach azimuth calculation unit 33 determines which route is currently present and how many kilometers to reach the next branch point, whether the approach direction to the next line is right or left turn, and the like. It is displayed as a comment or is notified by voice through the speaker 46.

Further, the comparison between the data of the passing route memory 26 and the data of the planned route memory 32 in the next branch point approach azimuth calculating unit 33 is based on the scheduled route memory 32 registered in advance.
Data and The matching is performed with the estimated route calculated in the section. During the matching operation, the deviation determination unit 47 determines that the difference between the data in the passage route memory unit 26 and the data in the planned route route memory 32 is a sensor correction range check unit.
When the number exceeds the sensor correction limit value of 24, it is displayed as a comment on the monitor 43 or output as a voice by the speaker 46 according to the number of times.

However, even if the road deviates significantly from the pre-registered road, if the optimal route is selected from the roads on the map, the road data is also saved, so it is passing through a route different from the planned road May be indicated. Also,
If the optimal route is not on the map road, there may be insufficient map data, so the value of the previous section is used as it is as the sensor detection amount correction amount, and the position is displayed with a certain figure around the final position at that time. You may make it.

In FIG. 1, reference numeral 48 denotes a recording / reproducing unit for recording / reproducing an IC card or a magnetic floppy.

In the present system, the scheduled route data from the departure point to the destination point stored in the scheduled route memory 32 can be stored and reproduced on the IC card or the magnetic floppy through the recording / reproducing section 48. Therefore, when the same route is used again, if the input planned route data is stored in an IC card or a magnetic floppy disk, the trouble of inputting can be saved and another person can use it.

Further, in this system, the contents of the IC card or the magnetic floppy can be read and reproduced on the monitor 43 through the recording / reproducing section 48. Therefore, for example, if data such as a guide map of a local place, a parking guide, a route guide with a still image, and the like are stored in an IC card or a magnetic floppy, such contents can be viewed when necessary, which is very convenient. .

Further, in FIG. 1, reference numeral 49 denotes a camera for confirming the rear.

In this system, the video output signal of the rear of the vehicle imaged by the
It can be recorded on a card or magnetic floppy.

Then, when traveling on the outbound route, each time a right or left turn is made, immediately after the right or left turn, a still image of the landscape is captured by the camera 49 for backward confirmation, and the contents are integrated into an IC.
In addition to recording on a card or a magnetic floppy, when the vehicle travels on the return trip, it reaches a point just before the branch point and reproduces a still image corresponding to the branch point on the monitor 43. Thereby, it can be used as a mark for turning right or left. At the time of traveling on the forward path, it is possible to recognize that the vehicle has arrived just before the branch point based on the output of the next branch point approach direction calculation unit 33. When the vehicle is traveling on the return path, it is determined that the vehicle has arrived just before the branch point based on the output of the next branch point approach direction calculation unit 33.
It is possible to recognize immediately after a right or left turn by detecting a point in time when the value of the output 12 greatly changes and then decreases.

In the embodiment shown in FIG. 1, the travel distance sensor 11 outputs the average of the rotational speeds of the driven left and right wheels and the travel distance obtained from the contact radius obtained from the tire diameter. In the case of all-wheel drive, the detection error is kept to a minimum by calculating and averaging the traveling distances of the four wheels by the above-described method. Also, at this time, an ultrasonic transceiver is provided on the axle provided with the wheel rotation detector, which is a component of the traveling distance sensor 11, and the time required for reflecting the ultrasonic output of the ultrasonic transceiver from the road surface is measured. The effective tire diameter from the wheel rotation center to the road surface may be calculated based on the measured time.

Further, as shown in FIG. 3, the traveling azimuth sensor 12 has a rotor 50 having an inertia force installed vertically to a vehicle body floor and rotated by a motor 51.

On the outer periphery of the rotor 50, a magnetic material is magnetized at equal intervals, or reflective / non-reflective materials are provided at equal intervals. The former is a reproducing head, the latter is a light emitting / receiving sensor and a pulse generator 52.
Is composed.

The bearing of the rotor 50 and the motor 51 are heated by the heater 53, and the temperature is detected by the temperature sensor 54. The microcomputer 55 controls the heater 53 so that the temperature becomes a constant temperature, for example, about 70 ° C. ± 10 ° C.

The microcomputer 55 averages the pulse period from the pulse generator 52 during the period when the output of the vehicle speed sensor 56 or the traveling distance sensor 11 is “0” and stores the averaged period in the memory. Find the phase difference of the detection pulse cycle,
The body direction change angular velocity is obtained from the angular velocity of the rotor 50.

This value is used as the sampling time Δt of the present system.
And output as an azimuth change angle Δθi.

In addition, since the rotation speed of the rotor 50 changes with time due to bearings and the like, in order to reduce the accumulated error,
When the vehicle is stopped, the comparison reference cycle is changed each time so that the output of the traveling direction sensor 12 becomes “0”. The feedback control with a small gain may be performed so that the rotation becomes constant over time.

By the way, in recent years, construction of a system for broadcasting traffic information, current position information of a vehicle, and the like by a broadcasting station, a road beacon (sign post system), and the like has been studied.

FIG. 4 is a diagram showing an embodiment of a car navigation system applied when it is assumed that such a social support infrastructure has developed. In the figure, the same elements as those shown in FIG. 1 are denoted by the same reference numerals.

Here, 61 is a receiver for radio waves transmitted from a broadcasting station or a road beacon, etc., and 62 is to determine whether the received data is information such as current position information or traffic congestion or traffic regulation in a specific section of a certain route, a detour instruction, etc. This is the information determining unit that performs the operation.

Reference numeral 63 denotes a current position data conversion calculating unit that converts the position information from the information determining unit 62 into a map coordinate system displayed on a monitor;
Reference numeral denotes a point-to-point azimuth / distance total calculation unit for calculating a total travel change angle A and a total travel distance B per minute movement amount from map data between two points on the way.

Further, 65 is a distance accumulation memory that accumulates and accumulates the traveling distance data saved by the traveling distance sensor output memory 13, and 66 accumulates and accumulates and saves the traveling orientation data saved by the traveling orientation sensor output memory 14. The azimuth angle change total memory 67 is a point-to-point azimuth, and a predetermined correction amount is calculated by comparing the data of the distance total calculator 64 with the data of the distance total memory 65 and the data of the azimuth angle change total memory 66. This is a sensor correction amount calculation unit.

Then, if the data received by the receiver 61 is merely position information, the current position data conversion calculation unit 63 converts the data into a map coordinate system and partially corrects the data in the passage route memory unit 26.

If the same position information is received during the passage, the point-to-point azimuth and distance total calculation unit 64 calculates the total travel change angle A per minute movement amount and the total movement distance B from the map data between the two points. Ask for.

Next, the sensor correction amount calculating section 67 compares the accumulated traveling change angle A and the data A 'of the azimuth angle accumulated change memory 66 with the total movement distance B and the data B' of the accumulated distance memory 65, respectively.
The correction amounts of A / A 'and B / B' are calculated.

Then, the data of these correction amounts is input to the sensor correction memory unit 22, and becomes reference values until the next external position information is obtained.

In addition, 68 is a road information selection unit that selects only data other than the current position data received by the receiver 61, such as traffic congestion, regulation detour instructions, parking lot guidance, slip caution, cross wind caution, etc., 69 A scheduled route relation data storage unit that selectively saves only information relating to a route along the planned route registered by the advance passage route registration unit 30 from these information.

Then, the information is output from the scheduled route relation data storage unit 69 to the image data memory 42 in accordance with the display map area,
The image is synthesized with the saved map data stored in the map storage device 41, and the synthesized image is displayed on the monitor 43. Note that the information from the scheduled route relation data storage unit 69 may be output as voice from the speaker 46.

When the present system is applied to a so-called sign post system, it can be implemented as follows.

The sign post system is, for example, a radius of 10 for each intersection.
This is a system that transmits individual information within a range around m. Here, the individual information includes, for example, as shown in FIG. 5, an ID code indicating the intersection, position information indicating the position of the intersection, and other traffic information.

In this system, first, data from the sign post is received by the receiver 61, and the current position data conversion calculator 63 converts the data into a map coordinate system. Then, the data of the map coordinate system is used as data of the passage route memory unit 26 as determined current position information.

By the way, the system with the least accumulated error in the map matching is one in which map matching is performed using output data of a global positioning system (GPS) that calculates the current position using several satellite radio waves.

However, if the GPS output data is not used, direct waves and reflected waves are mixed between city buildings and multi-story elevated roads, and errors are included.

Therefore, if the map matching method of the present system is used as it is, highly accurate position display can be performed.

That is, in FIG. 4, reference numeral 71 denotes a G for receiving a GPS signal.
The PS receiving unit 72 is a two-point moving distance and azimuth change amount calculating unit that calculates an approximate linear moving distance ΔLi and an azimuth change angle Δθi between two adjacent points from data of three consecutive points of the output signal of the GPS receiving unit 71. is there.

Then, the output data of the moving distance between two points and the azimuth angle change amount calculating section 39 may be input to the traveling distance sensor output memory 13 and the traveling azimuth sensor output memory 14.

On the other hand, the output of the GPS
When displaying on 3, the output of the GPS receiver 71 is the current (final)
What is necessary is just to input directly to the position memory unit 25 and stop the map mung operation.

[Effects of the Invention] As described above, according to the present invention, within the error range of the sensor for detecting the position of the vehicle and the error range of the road map,
Since the route pattern is changed based on the data obtained for each section and the pattern that best matches the road in the map is selected, the accumulated errors of the distance sensor and the direction sensor are minimized and accurate. Running display can be performed.

Further, since the corrected values of the output data of the azimuth and distance sensors are stored and used preferentially in the next section, the matching speed can be increased.

Furthermore, by registering the planned route in advance, when the direction of the route at the next branch point or future road information is input via the antenna, only the relevant data can be automatically selected and displayed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a car navigation system according to one embodiment of the present invention, FIG. 2 is a diagram for explaining a matching operation in the system shown in FIG. 1, and FIG. 3 is a diagram shown in FIG. FIG. 4 is a diagram showing a configuration of a car navigation system according to another embodiment of the present invention, FIG. 5 is a diagram for explaining a signal sent from a sign post, and FIG. 6 and 7 are views for explaining a conventional example. 10: travel distance / azimuth detection unit, 20: position estimation unit, 30: pre-passage route registration unit. 11: running distance sensor, 12: running direction sensor, 13: running distance sensor output memory, 14: running direction sensor output memory,
15 Section setting section. 21: section estimation route calculation unit, 22: sensor correction memory unit, 23
... Section end position (next section start position) calculation unit, 24 ... Sensor correction range check unit, 25 ... Current (final) position memory unit
26: Passage path memory unit. 31: planned route input check unit, 32: planned route route memory, 33: next branch point approach direction calculation unit. 41: map storage device, 42: image data memory, 43: monitor, 44: operation unit, 46: speaker.

Continuation of the front page (56) References JP-A-61-243482 (JP, A) JP-A-57-188082 (JP, A) JP-A-61-100811 (JP, A) JP-A-63-113310 (JP JP-A-59-30012 (JP, A) JP-A-58-121500 (JP, A) JP-A-1-142412 (JP, A) JP-A-64-59119 (JP, A) 61-79118 (JP, A) JP-A-64-59007 (JP, A) JP-A-60-45285 (JP, A) JP-A-1-114713 (JP, A) JP-A-62-5123 (JP, A A) Japanese Utility Model 2-33316 (JP, U) Japanese Utility Model 2-27178 (JP, U)

Claims (20)

(57) [Claims] 1. A distance sensor for detecting a traveling distance of a vehicle, a direction sensor for detecting a traveling direction at a traveling position of the vehicle, a traveling distance detected by the distance sensor, and each traveling detected by the direction sensor. Travel position / azimuth holding means for holding a travel azimuth at a position for a predetermined travel distance section; map data storage means for storing map data relating to a road; dividing the travel distance section into a plurality of sections; A route selection unit that selects a route that overlaps a road on the map stored by the map data storage unit by stepwise increasing or decreasing the traveling distance of each divided section and the traveling azimuth of the division position held by the unit. Display means for combining and displaying the route selected by the route selection means with the map data stored by the map data storage means; Car navigation system, characterized in that it comprises. 2. The car navigation system according to claim 1, wherein a small increase / decrease value holding means for holding a small increase / decrease value of a traveling distance of each divided section and a traveling azimuth of a divided position used for the route selection by said route selecting means. The route selecting means performs stepwise minute increase / decrease of the traveling distance of each divided section and the traveling azimuth of the divided position by preferentially using the minute increase / decrease value held by the minute increase / decrease value holding means. A car navigation system characterized by the following. 3. A distance sensor for detecting a traveling distance of the vehicle, a direction sensor for detecting a traveling direction of the vehicle, and the detected traveling distance and a traveling direction at each traveling position are held for a predetermined traveling distance section. Traveling position / direction holding means, map data storage means for storing map data relating to roads, current position holding means for holding one or more current positions on the map data, and the current position as a starting point, From the correlation between the map data and the travel distance and travel direction for a predetermined travel distance section,
A route selection unit for selecting one or more routes on the map road stored by the map data storage unit; and a map data stored by the map data storage unit, the route selected by the route selection unit. Display means for combining and displaying; rewriting means for rewriting the current position held by the current position holding means to the end of the path selected by the path selecting means; and a path selected by the path selecting means. A car navigation system comprising: an erasing means for erasing a corresponding current position retroactively from the current position holding means when the vehicle deviates by a predetermined amount or more from a road on the map stored by the map data storage means. 4. A distance sensor for detecting a traveling distance of the vehicle, a direction sensor for detecting a traveling direction of the vehicle, and the detected traveling distance and a traveling direction at each traveling position are held for a predetermined traveling distance section. Traveling position / azimuth holding means; planned route input means for sequentially inputting a planned route from a departure point to a destination point for each branch point of the road; map data storage means for storing map data relating to the road; Means for calculating road data corresponding to the planned route inputted by the means and the course direction change angle at the branch point from the map data stored in the map data storage means; and calculation by the planned route calculation means. The map data storage means is used based on the correlation between the map data and the mileage and azimuth of the predetermined mileage section while preferentially using the result. Route selecting means for selecting a route on a map road stored by the above, and display means for combining and displaying the route selected by the route selecting means with the map data stored by the map data storing means. A car navigation system characterized by: 5. The car navigation system according to claim 4, further comprising: means for judging whether the route selected by said route selecting means deviates by more than a predetermined value from the result calculated by said scheduled route calculating means, and And a means for notifying the user when the car navigation system is in use. 6. The car navigation system according to claim 4, wherein a route selection data holding unit that holds data used for selecting a route by the route selection unit, and the route selected by the route selection unit is the scheduled route calculation. Position calculation means for calculating a current position based on the data held in the route selection data holding means when the calculation result by the means deviates by a predetermined amount or more or when there is no route selected by the route selection means; Means for characteristically displaying the current position on the display means. 7. A distance sensor for detecting a traveling distance of the vehicle, an azimuth sensor for detecting a traveling azimuth of the vehicle, and the detected traveling distance and a traveling azimuth at each traveling position are held for a predetermined traveling distance section. Travel position / azimuth holding means, map data storage means for storing map data relating to roads, and storage by the map data storage means from a correlation between the travel distance and travel orientation for the predetermined travel distance section and the map data. Route selection means for selecting a route on the selected map road, planned route input means for sequentially inputting a planned route from a departure point to a destination point for each branch point of the road, and input by the planned route input means. A scheduled route calculation that calculates road data corresponding to the scheduled route and a course direction change angle at the branch point from the map data stored in the map data storage unit. Means for determining whether or not the vehicle has reached a predetermined distance before the branch point based on a comparison between the result of calculation by the scheduled path calculation means and the path selected by the path selection means; When the first determining means determines that the vehicle has reached a predetermined distance before the branch point, a second determination is made based on the course direction change angle at the branch point calculated by the planned route calculating means. And a notifying means for notifying a result of the judgment by the second judging means. 8. The car navigation system according to claim 4, wherein a check is made as to whether there is a branch point that has not been input between the start point and the end point of the planned route input by the planned route input means. And a means for notifying when there is a branch point that has not been input. 9. The car navigation system according to claim 1, 3 or 4, wherein the distance sensor controls the rotation speed of the driven left and right wheels by four-wheel drive or anti-lock. In the case of a vehicle equipped with a brake system, a car navigation system detects the number of revolutions of all wheels, calculates the respective traveling distances from the tire diameters input from the outside, and averages them. 10. The car navigation system according to claim 9, wherein an ultrasonic transceiver is provided on an axle provided with a wheel rotation detector as a component of the distance sensor, and a road surface of an ultrasonic output of the ultrasonic transceiver. A car navigation system comprising: means for measuring a time required for reflection from a vehicle; and means for calculating an effective tire diameter from a wheel rotation center to a road surface based on the measured time. 11. The method according to claim 1, 3 or 4,
8. The car navigation system according to claim 7, wherein the azimuth sensor includes: a rotating body having an inertial force whose center axis is held perpendicular to a vehicle body floor; a torque generating unit that drives the rotating body; Pulse generating means for generating a predetermined pulse according to the rotation of the rotating body, wherein when the output of the distance sensor is "0", the pulse generating means counts the number of pulses per unit time, The average pulse period is stored, and when the output of the distance sensor is other than “0”, the phase difference from the pulse generated from the pulse generating means is detected based on the stored average pulse period, so that the vehicle body is detected. A car navigation system characterized by conversion into a direction change angle. 12. A car navigation system according to claim 11, wherein said heating means heats said torque generating means, a temperature measuring means measures a temperature of said torque generating means, and Control means for controlling the heating means so that the torque generating means has a constant temperature. 13. The car navigation system according to claim 4, wherein the data relating to the planned route from the departure point to the destination inputted by the planned route input means or calculated by the planned route calculating means. A car navigation system wherein data relating to a scheduled route can be stored and reproduced on a portable recording medium. 14. The method according to claim 1, 3 or 4,
8. The car navigation system according to claim 7, wherein a portable recording medium storing character data or still image data can be reproduced. 15. The car navigation system according to claim 4, wherein a video camera directed to the rear of the vehicle, means for recording / reproducing a video output signal from the video camera, and a right / left turn when traveling on a forward road. A car navigation system, comprising: means for recording a still image by the video camera for each time; and means for reproducing the still image a predetermined distance before each right or left turn when traveling backward. 16. The car navigation system according to claim 15, wherein first detection means for detecting that the vehicle has arrived before the junction based on the planned route input by the planned route input means, and the direction sensor. Second detection means for detecting that the value of the output has changed by a predetermined amount or more, when the second detection means detects that the vehicle has arrived immediately after the branch point during forward traveling, A car navigation system characterized by recording a still image with a video camera, and reproducing the still image after the first detecting means detects that the vehicle has reached a point just before the branch point when the vehicle travels on the return route. 17. A car navigation system according to claim 4, wherein said receiving means receives a radio wave transmitted from an external transmitter, and data received by said receiving means and a schedule inputted by said scheduled route input means. Determining means for determining whether the received data is data related to the scheduled route by comparing with the data related to the route; and storing the data when the received data is data related to the scheduled route. Storage means, and when the data stored by the storage means is related to the displayed map data, the data stored by the storage means are combined with the map data and displayed on the display means. A car navigation system, comprising: 18. The car navigation system according to claim 2, wherein when at least two fixed position inputs are made in the passing route section, the total azimuth change angle and the total distance are calculated from the map data for the route between these two points. A first calculating means for calculating a number, a second calculating means for calculating a total of output data of the azimuth sensor and the distance sensor, and a calculation result by the first calculating means and the second calculating means. Correction means for correcting the value held by the small increase / decrease value holding means based on a comparison with the calculation result. 19. A car navigation system according to claim 18, further comprising: receiving means for receiving a radio wave of the current position data transmitted from a transmitter installed on the roadside, and transmitting the received current position data to the map data. Conversion means for converting the current position data into a coordinate system, wherein the converted current position data is inputted as a fixed position in the first calculation means and displayed as the current position on the display means. system. 20. Claims 1, 3 and 4
The car navigation system according to claim 7 or 8, wherein output data of a global positioning system that receives a unique radio wave emitted from several satellites and obtains a current position of the vehicle instead of the distance sensor and the direction sensor is used as the map. A car navigation system comprising: means for converting data into a coordinate system; and means for calculating a linear moving distance and a traveling change angle from the converted output data of two adjacent points obtained at predetermined time intervals. system.