JPH03123383A - Position display device for vehicle - Google Patents

Abstract

PURPOSE:To display an accurate vehicle position by providing an azimuth detecting means, a proceeding azimuth arithmetic means, a distance detecting means and a present position candidate range arithmetic means and deciding the present position based on the comparison with previously stored map information. CONSTITUTION:A CPU 19 calculates a proceeding azimuth theta and its error range DELTAtheta based on a detected azimuth thetaM1 by an earth magnetism sensor 11 and an angular speed DELTAthetaG from a gyro device 13. Then, based on the calculated azimuth theta and a vehicle speed pulse from a vehicle speed sensor 15, the expected present position is calculated. Data of the roads in the vicinity of the calculated expected present position is retrieved from a map memory 23 and the shapes of the peripheral roads are extracted. If a registered road exists, the calculated expected present position is displayed on an image display device 25 as the confirmed present position corrected at the position on the road. When the registered road is not present, the expected present position is displayed on the device 25 as the confirmed present position. Thus, the accurate vehicle position is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vehicle position display device that displays the current position of the own vehicle.

(Prior Art) As display devices have become smaller and more environmentally resistant in recent years, it has been considered to mount them on vehicles to provide various information to passengers.

Incidentally, one of the pieces of information provided to passengers via a display device is the current position of the own vehicle, and various types of information have been put into practical use or proposed.

As such a device, for example, Utility Model Application No. 62-173016
The vehicle map guide device disclosed in the above issue has been proposed. This vehicle map guide device includes a display means for displaying a road map, the current position on the road map, a moving direction, etc., and a map calculation means for inputting a signal indicating the road map or the current position of the vehicle to the display means. , a position calculation means for inputting current position data of the vehicle into the map calculation means;
a position detecting means for inputting a signal indicating the traveling direction and traveling speed of the vehicle to the position calculating means; the position detecting means includes at least an azimuth sensor; The present invention is characterized in that it includes a traveling locus display correction means for correcting the display so that when the traveling locus that connects the current positions displayed deviates from the road on the map, the display is returned to the road.

(Problem to be Solved by the Invention) Although the above-mentioned device can always display the appropriate vehicle position along the road on the map, it is difficult to display due to the limited capacity of the memory that stores map information. If you drive on an unregistered road when a registered road exists, the current location determined on the memorized nearby road will be forcibly corrected, resulting in an incorrect location being displayed. This issue should be resolved. There are challenges.

The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle position display device that enables accurate vehicle position display regardless of stored map information.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a device that causes a display device installed in a vehicle to display a required map and the current position of the own vehicle on this map. The invention is as shown in Figure 1.
A plurality of direction detection means 1 having different characteristics for detecting the direction of movement of the vehicle; a direction calculation means 3 for calculating the direction of movement of the vehicle and its error range based on the direction of movement detected by each direction detection means 1; distance detecting means 5 for detecting the traveling distance of the vehicle; current position candidate range calculating means 7 for calculating the vehicle's current position candidate range based on the detected travel distance, the determined traveling direction of the vehicle, and its error range; The gist of the present invention is to include determining means 9 for determining the current position from the current position candidate range based on a comparison between the current position candidate range and map information stored in advance.

(Function) The vehicle position display device according to the present invention has a plurality of azimuth detection means 1 having different characteristics, and the traveling azimuth of the vehicle is determined based on the traveling azimuth detected by each azimuth detection means 1. The current position candidate range of the vehicle is determined based on the error range and the travel distance of the vehicle, and the current position is calculated from the current position candidate range based on the comparison between the calculated current position candidate range and pre-stored map information. is determined and displayed.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 is a circuit block diagram of a vehicle position display device according to an embodiment of the present invention. In the same figure, 11 and 13
15 constitute direction detection means, and include a geomagnetic sensor and a gyro device, respectively, for detecting the direction of travel of the vehicle.
17 is a vehicle speed sensor, and 17 is an operation switch with which the driver performs operations such as changing the size of the displayed map. These are connected to a microcomputer 19, and their outputs are processed by this microcomputer 19. The microcomputer 19 controls the overall operation, and is connected to a memory 21 for storing other necessary data, a map memory 23 for storing map information, and an image display device 25. The microcomputer 19 constitutes a heading calculation means, a distance detection means, a current position candidate range calculation means, and a determination means.

Next, the operation of this embodiment will be explained using the processing flowchart of the microcomputer 19 shown in FIG.

The microcomputer 19 clears the non-registration flag indicating that the user is driving on a road that is not registered in the map memory 23 (hereinafter referred to as "non-registered road") due to engine start, etc., at regular intervals T. Geomagnetic sensor 11
, the input of the detection results by the gyro device 13 and the vehicle speed sensor 15 is started (steps 100 and 110).

When the detection results are input, the microcomputer 19 determines the most probable current vehicle heading θ based on the detected heading θM1 by the geomagnetic sensor 11 and the angular velocity ΔθG from the gyro device 13, and the error range of this heading θ using the following formula. Δθ is calculated (step 120).

Δθ = "Temple ΔθG - ΔθM Here, ΔθM is the difference between the azimuth θMQ of the previous detection valve and the azimuth θMl of the current detection valve in the geomagnetic sensor 11, and " is a coefficient, which is a constant value or the output signal of the geomagnetic sensor 11. This value is determined by the magnitude of the fluctuation component of , and is a value that has been set in advance experimentally and empirically.

Thereafter, the microcomputer 19 calculates the expected current position (x, V) based on the calculated heading θ and the vehicle speed pulse from the vehicle speed sensor 15 using the following formula (
Step 130).

X = X o + 1 cos θ V = V o 1 L Sin θ Here, Xo and Vo indicate the X and Y coordinates of the vehicle position at the time of previous detection, respectively. Alternatively, it indicates the traveling distance from the time of previous detection to the time of current detection, and is a value that can be calculated from the constant R interval T and the number of vehicle speed pulses.

Next, the microcomputer 19 stores the calculated road data in the vicinity of the predicted current position (x, y) in the map memory 2.
Search from step 3 and extract the surrounding road shape (step 1
40). Then, the state of the non-registration flag is determined, and if it is a reset state (OFF state), the process proceeds to step 160, and if it is a set state (ONN state), the process proceeds to step 210 (step 150).

Proceeding to step 160, the microcomputer 19 determines whether there is a road registered within the error range of 0 for the vehicle traveling direction θ calculated in step 120 (step 170).

As a result of this determination, if there is a registered road R, the predicted current position (x
. It is determined that the vehicle is traveling on a road, a non-registration flag is set, and the predicted current position (x, y) is displayed on the image display device 25 as the confirmed current position (steps 190, 200, and 250).

On the other hand, when proceeding to step 210, the microcomputer 19 calculates the degree of coincidence between the surrounding road shape and the series of travel trajectories including the predicted current position (X, V) calculated in step 130, and if the degree of coincidence is low, It is determined that you are still driving on an unregistered road, and the estimated current position (x,
V) is displayed on the image display device 25 as the confirmed current position (steps 220 and 250>.On the other hand, if the degree of coincidence is high, it is determined that the previous detection that the vehicle was traveling on an unregistered road was incorrect and is corrected. Then, the non-registration flag is reset, and the predicted current position (x, y) is corrected to a position on the registered road with a high degree of coincidence, and is displayed as the confirmed current position (steps 220 and 250).

Therefore, according to this embodiment, the predicted current position is almost never on a registered road due to various detection error factors such as disturbances in the geomagnetic field of the orientation sensor and the approach of large vehicles. Instead of forcibly correcting the position on one of the registered roads as in the past, the position is corrected as necessary based on the results of a predetermined judgment process that takes into account the detection error factors. Because there are
It is possible to achieve more accurate display than conventional devices, such as displaying the location even when driving on an unregistered road.

[Effects of the Invention] As explained above, according to the present invention, a plurality of azimuth detection means 1 having different characteristics are provided, and the traveling azimuth of the vehicle determined based on the traveling azimuth detected by each azimuth detection means and its The current position candidate range of the vehicle is determined based on the error range and the distance traveled by the vehicle, and the current position is determined from the current position candidate range based on a comparison between the calculated current position candidate range and pre-stored map information. Since the vehicle position is displayed, the accurate position of the vehicle can be displayed regardless of the stored map information.

[Brief explanation of drawings]

FIG. 1 is a diagram corresponding to claims, FIG. 2 is a circuit block diagram of an embodiment of the present invention, FIG. 3 is a processing flowchart of the embodiment, and FIG. 4 is a diagram for explaining the operation. DESCRIPTION OF SYMBOLS 1... Azimuth detection means 3... Travel direction calculation means 5... Distance detection means 7... Current position candidate range calculation means 9... Determination means 11... Geomagnetic sensor 3.
... Gyro device 15 ... Vehicle speed sensor 7 ... Operation switch 9 ... Microcomputer ... Memory 23 ... Map memory 5 ...
・Image display device

Claims (1)

[Claims] A device that causes a display device installed in a vehicle to display a required map and the current location of the vehicle on this map,
A plurality of direction detection means having different characteristics for detecting the direction of travel of the vehicle, a direction calculation means for calculating the direction of travel of the vehicle and its error range based on the direction of travel detected by each direction detection means, and a distance traveled by the vehicle. a current position candidate range calculation means for calculating a candidate range of the vehicle's current position based on the detected traveling distance, the determined traveling direction of the vehicle, and its error range; and the determined current position candidate range. and determining means for determining the current position from a current position candidate range based on a comparison between the current position and map information stored in advance.