JPH04188016A - Present-position detecting apparatus for vehicle - Google Patents

Abstract

PURPOSE:To detect the present position of a vehicle highly accurately by correcting the present position of a vehicle based on a reference point when it is judged that the vehicle has reached the vicinity of a reference point which has been specified in the data stored in a memory means. CONSTITUTION:A present-position computing means 7 obtains the bearing data and the distance data from a bearing sensor 3 and a distance sensor 5, respectively, and sequentially computes the present position on the map associated with a running path stored in a memory means 1. In a judging means 9, a reference point for correcting the present position of the vehicle in the map data stored in the memory means 1 is read out based on the computed present position. When it is judged that the vehicle reaches the reference point or its vicinity, the present position of the vehicle is corrected with a correcting means 11 based on the reference point. Therefore, the running locus of the vehicle is adequately compared with the road on the map, and the present position of the vehicle can be detected highly accurately.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a current position detection device for a vehicle, and particularly relates to a current position detection device for a vehicle that detects the current position of a vehicle with high accuracy. be.

(Prior art) In recent years, the current position of a vehicle is calculated sequentially based on direction information from a direction sensor and distance information from a distance sensor, and the vehicle's travel trajectory and current position of the vehicle are displayed on a map. Various so-called navigating stems have been developed (Japanese Patent Application Laid-open No. 61-243482).
).

In such conventional navigation systems,
When the current position of the vehicle is calculated one after another, the travel trajectory of the vehicle is calculated based on the data of the current position of the vehicle every predetermined distance traveled or every time a predetermined time elapses.

The calculated travel trajectory is then compared with the shape of the road on the map to calculate the degree of agreement between the two, and the current position of the vehicle is corrected to the road with a high degree of agreement. .

FIG. 5 shows processing related to correction of the current position of a vehicle in a conventional navigation system.

As shown in FIG. 5(A), after driving on road TRa on the map and passing point Pa, road TRa at point pb
There are cases where the road branches into road a, road TRb, and road TRc. In such a case, when driving a predetermined distance from point Pa to point Pc, from this point Pa to point Pc
When the travel trajectory TRd up to
Rd and the shape of the road on the map are compared.

(Problem to be solved by the invention) Figure 5 (B) shows the traveling trajectory TRd and the road TRa on the map.
, shows a comparison with the shape of TRb, and Figure 5 (
C) is the driving trajectory TRd and the roads TRa and TRc on the map.
This figure shows a comparison with the shape of .

In this way, when comparing the entire traveling trajectory TRd from point Pa to point Pc via the branch point with the road on the map, the road TRa on the map is as shown in FIG. 5(C).
The degree of matching with the route from to road TRc becomes high.

However, as shown in FIG. 5(B), the final point Pc
Focusing on the driving trajectory TRd in the vicinity of , that is, the driving trajectory TRd from the point corresponding to point pb, which is the above-mentioned branch point, to the final point Pc, the degree of coincidence with the route from road TRa to road TRb on the map is It gets expensive.

Therefore, when comparing the entire traveling trajectory TRd with the road on the map, the current position of the vehicle will be corrected to be on the road TRc, and conversely, the current position of the vehicle will be corrected to be on the traveling trajectory TRd near the final point Pc. When paying attention to the road and comparing it with the road on the map, the current position of the vehicle will be corrected to be on the road TRb.

As mentioned above, depending on which part of the calculated driving trajectory is focused, the degree of correspondence with the road on the map will differ, making it impossible to make appropriate judgments. Difficult to detect.

The present invention has been made in view of the above-mentioned problems, and provides a current position detection device for a vehicle that can appropriately compare the travel trajectory of the vehicle with roads on a map and detect the current position of the vehicle with high accuracy. The purpose is to provide.

[Configuration of the Invention (Means for Solving the Problems) To achieve the above object, the present invention, as shown in FIG. A direction sensor 3 for obtaining distance information, a distance sensor 5 for obtaining distance information, and direction information and distance information obtained from the direction sensor 3 and distance sensor 5, respectively, and the current position on the map stored in the storage means 1. and a reference point for correcting the current position of the vehicle, which is map information stored in the storage means 1 from the current position sequentially calculated by the current position calculation means 7. Alternatively, if the determining means 9 determines that the vehicle has arrived at the reference point or the vicinity of the reference point, the vehicle's current position is determined by the determining means 9. The gist of the present invention is to have a correction means 11 for making corrections based on the reference point.

(Function) In the current position detection device for a vehicle of the present invention, the current position calculation means 7 obtains direction information and distance information from the direction sensor 3 and the distance sensor 5, respectively, and stores them in the storage means 1. The current position on the map related to the road is calculated sequentially.

Further, the determining means 9 reads a reference point for correcting the current position of the vehicle from among the map information stored in the storage means 1 from the calculated current position, and reads the reference point or its When it is determined that the vehicle has arrived nearby, the modification means 11 modifies the current position of the vehicle based on the reference point.

Therefore, the current position of the vehicle can be detected with high accuracy by appropriately comparing the travel trajectory of the vehicle with the road on the map.

(Embodiment) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, the configuration will be explained with reference to FIG.

The microcomputer 13 includes an azimuth sensor 15 for obtaining azimuth information via an interface circuit (not shown);
Vehicle speed sensor 17 which is a distance sensor for obtaining distance information
, and are connected to various sensors and switches of the operation switch 19.

The direction sensor 15 is composed of a geomagnetic sensor that detects the absolute running direction of the vehicle, a gyro sensor that detects the relative running direction of the vehicle, etc., and detects the direction or a change in the direction depending on the direction in which the vehicle is running. Outputs a signal proportional to the amount.

The vehicle speed sensor 17 is comprised of, for example, a photoelectric type, electromagnetic type, or mechanical contact type sensor, and generates a pulse signal every time the vehicle travels a predetermined distance. This vehicle speed sensor 17 is
For example, it outputs a pulse signal proportional to the number of rotations of the wheels.

This vehicle speed sensor 17 constitutes a distance sensor.

The operation switch 19 is provided at an appropriate position such as a driver's seat or a passenger's seat of the vehicle. Further, the operation switch 19 is composed of various switches such as a switch for displaying the vehicle's current position, travel trajectory, etc. together with map information, and a switch for enlarging or reducing the displayed contents.

The microcomputer 13, the direction sensor 15, and the vehicle speed sensor 17 constitute a current position calculation means, which sequentially calculates the current position on the map of the road on which the vehicle is traveling.

Specifically, the microcomputer 13 has an arithmetic processing section for performing arithmetic processing, and when a pulse signal from the vehicle speed sensor 17 is input, the microcomputer 13 counts the number of pulses of the input pulse signal and calculates the speed of the vehicle. Calculate the distance traveled. Furthermore, the microcomputer 13 sequentially calculates the current position of the vehicle on two-dimensional coordinates in the X-axis direction and the Y-axis direction based on the azimuth information from the geomagnetic sensor and the gyro sensor and the calculated travel distance. do.

Further, the microcomputer 13 selects an arbitrary reference point on the map, and also includes a judgment means for judging whether the vehicle has arrived at the reference point or the vicinity of the reference point, and a judgment means for judging whether the vehicle has reached the reference point or the vicinity of the reference point. When it is determined that the vehicle has reached the vicinity of the reference point, the vehicle is provided with a correction means for correcting the current position of the vehicle based on the reference point. Furthermore, the microcomputer 13 uses the current position corrected by the correcting means as a starting point, and at every predetermined distance traveled or every predetermined period of time, the microcomputer 13 determines the traveling trajectory of the vehicle from the starting point and the shape of the traveling route on the map. The present invention also includes a correction means for calculating the degree of coincidence between the two and for correcting the current position of the vehicle to a traveling road on which the calculated degree of coincidence is high.

The CD-ROM 21 stores, for example, 1/100,000 scale map information, 1/25,000 scale map information, information regarding the aforementioned set reference points, etc. according to a preset format. This CD-ROM 21 is a storage means for storing map information of the route on which the vehicle travels.

The memory 23 is a ROM in which various control programs are stored.
, a control RAM for performing various control processes, and the like.

The display device 25 displays the vehicle's current position, travel trajectory, etc. together with map information.

Next, the operation will be explained with reference to FIGS. 3 and 4.

In step S1, sensor signals, that is, direction information from the direction sensor 15 and distance information from the vehicle speed sensor 17, are converted into digital signals. As a result, the traveling direction θ of the vehicle and the traveling route ML are sequentially calculated.

In step S3, the current position (XN, YN) of the vehicle is calculated. If the previous position is (Xo, Yo), the current position of the vehicle (XN, YN) is shown as follows.

XN-Xo+Lcosθ YN-Yo+Ls inθ The current position of the vehicle (XN, Y
N) data is stored in the CD-ROM 21 (step S5).

Next, in step S7, it is determined whether or not to correct the current position. That is, the step S7 determines whether a predetermined amount of data on the vehicle's current position 1f (XN, YN) has been accumulated, and if the accumulation of data on the vehicle's current position is less than the predetermined amount, the data is restarted. The process returns to step S1 to continue accumulating data of the current position. Further, in step S7, if a predetermined amount of data on the current position of the vehicle has been accumulated, it is determined that the current position should be corrected and the process proceeds to step S9. In step S9, the CD-ROM2
Search the road data stored in 1. Subsequently, in step Sll, data of a forced judgment point, that is, a preset reference point is searched.

Next, in step 513, it is determined whether or not the current position should be forcibly corrected.

That is, in steps S] and 3, it is determined whether the vehicle has reached a preset reference point or its vicinity, and if the vehicle has not reached the preset reference point or its vicinity, The process advances to step S17.

Here, based on the above criteria, the position coordinates of the point pb where the road TRa branches to the roads TRb and TRc are stored in the CD-ROM2.
1 is stored. In addition to the above-mentioned branch point or intersection, a point where the output of the geomagnetic sensor is likely to be disturbed is selected as a reference point at which such a correction judgment of the current position should be made forcibly. For example, if a railway bridge, tunnel, substation, railroad crossing, etc. exist on or near the running route, a point immediately before such a point is selected as the reference point.

As shown in FIG. 4(A), a process will be described when a vehicle departs from point Pa on road TRa and reaches point Pd. If the travel trajectory of the section from point Pa to point Pd is calculated, and based on this travel trajectory it is determined that point Pd exists within a predetermined range from point Pb, which is a preset reference point. , the current position correction process is forcibly executed (step 513.S15). As a result of the current position correction process in step S13, 515, the current position of the vehicle is corrected from point Pd to point pb.

Next, as shown in FIG. 4(B) and (C), the vehicle moves to point p.
The process when the vehicle passes point P, travels a predetermined distance, and reaches point Pc will be described.

As mentioned above, each time a predetermined amount of data on the current position of the vehicle is accumulated, the current position is corrected by comparing the travel trajectory and the road shape. Determine whether a road exists or not. Since there are multiple routes from point pb to roads TRb and TRc, the process advances from step 517 to step S19. In step S19, a so-called residual sum of squares is calculated for each route with respect to the travel locus. That is, point pb
The difference in shape between the traveling trajectory TRf and the road TRb from point Pc to point Pc is calculated as the degree of coincidence, and the difference in shape between both the traveling trajectory TRf and the road TRc is calculated as the degree of coincidence.

In step S21, the optimum route, ie, the road on the map on which the vehicle has traveled, is selected in accordance with the above-mentioned match value. As is clear from Fig. 4 (B) and (C), the traveling trajectory TRf
Since the degree of coincidence between the road TRb and the road TRb is high, the road TRb is selected as the road on the map on which the vehicle traveled.

In step S25, it is determined whether or not the determination process has been completed for all travel trajectories. If the determination process has not been completed for all travel trajectories, step S25 is again performed.
Return to step 3 and execute the above-mentioned process. Also, step S2
If the determination process has been completed for all travel trajectories in step 5, the process returns to step S1 again.

As described above, if it is determined that the current position is at a preset reference point or within a predetermined range from the reference point, the current position is forcibly corrected based on this reference point. With this configuration, the current position can be appropriately corrected.

In the above embodiment, in step S7, when a predetermined amount of vehicle current position data has been accumulated, the current position is determined to be corrected every predetermined travel distance. The present invention is not limited to this, but it may be configured such that the current position is corrected at an appropriate timing, for example, every predetermined period of time.

By configuring as described above, the device configuration can be simplified.

[Effects of the Invention] As explained above, according to the present invention, a reference point is specified from among the information stored in the storage means, and the vehicle is able to locate the reference point,
Alternatively, when it is determined that the vehicle has reached the vicinity of a reference point, the current position of the vehicle is corrected based on the reference point, so that the vehicle's travel trajectory and the road on the map can be appropriately compared. It is possible to detect the current position of the vehicle with high accuracy.

[Brief explanation of the drawing]

Fig. 1 is a claim correspondence diagram, Fig. 2 is a block diagram of an embodiment according to the present invention, Fig. 3 is a flowchart showing the operation of the embodiment according to the present invention, and Fig. 4 is a diagram of the embodiment according to the present invention. FIG. 5 is an explanatory diagram showing processing related to correction of current position. FIG. 5 is an explanatory diagram showing processing related to correction of current position in a conventional example. 1... Storage means 3... Orientation sensor 5... Distance sensor 7... Current position calculation means 9... Judgment means 11... Correcting means substitute Person Patent Attorney Hidekazu Miyoshi Figure 1 Figure 2 (A) (B) (C) Figure 4 Figure 5

Claims (1)

[Scope of Claims] A storage means for storing map information related to a driving route, a direction sensor for obtaining direction information, a distance sensor for obtaining distance information, and a method for obtaining direction information from the direction sensor and the distance sensor, respectively. a current position calculation means that obtains the distance information and sequentially calculates the current position on the map stored in the storage means; and from the current position sequentially calculated by the current position calculation means,
A determination means for determining whether the vehicle has arrived at a reference point or the vicinity of the reference point for correcting the current position of the vehicle, which is map information stored in the storage means; or a correction means for correcting the current position of the vehicle based on the reference point when it is determined that the vehicle has reached the vicinity of the reference point.