JPS6366413A - Vehicle path guide apparatus - Google Patents

Abstract

PURPOSE:To accurately measure a position even in a road running wherein a radio wave reflection or the like is generated and enable effective path guide to be performed by prohibiting the correction of a measured value when a measuring radio wave has a low reliability in accordance with a running road. CONSTITUTION:Hybrid type position measuring means 1 is composed of a global positioning system (GPS) receiver, a range sensor, a bearing sensor and a CPU. First, the means 1 obtains the present vehicle position while correcting an assumed position obtained by integrating a unit running vector based on a position measured by a radio wave. Then, on the basis of the present position obtained by the means 1, vehicle path guide is performed by path guide means 2 (CRT and the like). On the other hand, reliability data storage means 3 (external memory and the like) stores the measuring reliability of a radio wave measurement defined on the basis of the degree of superiority of a radio wave receiving environment on a road. Correction prohibiting means 4 (CPU and the like) retrieves reliability data in accordance with the running road and, when the radio wave measurement has a low measuring reliability, prohibits a correction. Thus, the correct path guide can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a route guidance device for a vehicle equipped with a hybrid position measuring device.

[Prior Art] An example of a vehicle route guide device equipped with a conventional hybrid measuring device is the one shown in Japanese Patent Application Laid-Open No. 135817/1983 (travel guide device in Japan FJL). .

This is equipped with a radio wave position measuring device and an estimated position measuring device, and when the radio wave reception condition of the radio wave position measuring device becomes poor,
The purpose is to switch the radio wave position meter 3i11 device to an estimated position measuring device to constantly measure accurate vehicle position.

However, such conventional route guidance devices for vehicles are configured to use the position measured by radio waves when radio waves can be measured, and also correct the estimated position. However, there is a problem in that the estimated position may be unnecessarily shifted from the true position, causing trouble in route guidance.

For example, the radio wave position measuring device is GPS (GlobalP
osisitioning S'/5tf3+1
1, D OP (D 1
Even if the fusion of precision) value is good, in an environment where reflected waves from buildings or the like are being picked up, the so-called pseudo distance may be longer than the page distance, resulting in poor accuracy.

Also, for example, if the radio wave position measuring device is an O-run or the like,
Even if the strength of the received radio waves is strong, the accuracy may be poor due to radio wave diffraction.

[Object of the Invention] This invention improves the above-mentioned problems, and provides a route for vehicles that can accurately measure position and provide effective route guidance even when driving through passages where radio waves are reflected, diffracted, etc. The purpose is to provide a guidance device.

[Summary of the Invention] In order to achieve the above object, the present invention provides a route guidance device for a vehicle that uses a radio wave measured position to estimate a position obtained by integrating a unit travel vector, as shown in FIG. A hybrid position measuring means 1 that calculates the current position of the vehicle while correcting it, a route guidance means 2 that appropriately guides the vehicle by using the current position measured by the means 1, and a radio wave reception environment on each road. a reliability data storage means 3 for storing the measurement reliability of the radio wave measurement defined based on the superiority or inferiority of each road; and a reliability data storage means 3 for storing the measurement reliability of the radio wave measurement for each road; A correction prohibiting means 4 for prohibiting the correction is provided, and only estimated position measurement is performed on roads where unexpected measurement errors may occur due to reflection, diffraction, etc.

[Example] Hereinafter, the present invention will be described in detail using the accompanying drawings.

First, to briefly explain the drawings, FIGS. 2 to 7 show an embodiment of the present invention, FIG. 2 is a block diagram of a vehicle route guide device, and FIG. 3 is an explanation of a block map. 4 is a memory map of the external memory. or,
FIG. 5 is a memory map of the road data storage area, FIG. 6 is a data format of road data, and FIG. 7 is a flowchart of positioning processing.

As shown in FIG. 2, the vehicle route guidance device includes a system bus 5, a GPS receiver 6, a CPU 7, and a system R.
OM8, RAM9, sensor interface 10, video RAM11, and operation panel interface 1
2, an input operation section 13, and an external memory 14 are connected to each other. The sensor interface 10 includes
A distance sensor 15 that outputs a predetermined amount of pulse signals every time the vehicle travels a certain distance and a direction sensor 16 that detects the heading direction of the vehicle are connected. A CRTl 7 is connected to the video RAM 11. A transparent operation panel (touch panel) 18 provided on the front surface of the CRT 17 is connected to the operation panel interface 12.

The GPS receiver 6 includes an antenna 6A;

By receiving satellite radio waves for a combination with a good P value (0〒), the vehicle position is measured every predetermined time (for example, 5 seconds), and the measured position is provided to the CPU 7.

The CPU 7 performs calculations of estimated (integral) positions, correction of estimated positions, and various other route guidance devices based on programs stored in the system ROMB.

Here, the estimated position is calculated by inputting the output signals (vehicle speed signal and traveling direction signal) from the distance sensor 15 and the direction sensor 16 via the sensor interface 10, and multiplying the current position (reference position) by the travel vector. This is done by determining a new current position (estimated position).

Further, the estimated position is corrected by replacing the reference position in the calculation of the estimated position with the position measured by the GPS receiver 6. However, this modification is not performed under certain conditions, as detailed in FIG.

The GPS receiver 6 is connected to a distance sensor 15 and a direction sensor 16, and is combined with a CPU 7 that calculates an estimated position to form a hybrid position measuring means 1.

The CRTI 7 is for displaying guidance and the like.

The operation panel 18 is used to input the starting point and destination. The input operation unit 13 is formed of a so-called keyboard, and various commands can be issued by operating the keyboard.

As shown in FIG. 3, the map 19 expressed in XY coordinates consists of blocks (1-1), (1-2) of size α and β.
)...(3-3), and the external memory 14 records various information for each block 4! ! It is said to be shaped like this.

As shown in FIG. 4, the external memory 14 has various storage areas.

The area start address storage area M1 is the area M1. This is an area for storing the start address of M2...

The road data storage area VA M2 stores the start and end point coordinates of the straight-line approximated road segment J1 shown in FIG. 3, information necessary for route guidance related to the line segment i, and radio wave measurement This is an area for storing reliability.

As shown in FIG. 5, the road data storage area M2 includes an area M2-1 at the beginning that stores the start address of each map block (see FIG. 3), an area 'fJ that stores the road data in each block, M2-2.

M2-3... is on the right.

As shown in FIG. 6, the road data is configured such that reliability is stored in association with the start point coordinates and end point coordinates of the road segment intersection 1 approximated by a straight line.

The reliability data (1 or 0) indicates that there is a high possibility that the GPS receiver ta6 will measure the wrong position due to the influence of reflected waves from buildings, etc., and ``Oj'' indicates that there is no such possibility.
This data is defined as "1".

Reliability data can be calculated by driving a test vehicle (not shown) for understanding the radio wave environment on all roads and measuring the presence or absence of reflection, etc., and inserting it into the road data as shown in Figure 4. It is. However, since the satellite moves on a predetermined orbit and the state of reflection changes depending on the time, the reliability shown in FIG. 4 may be conditioned on the time (time zone).

Referring again to FIG. 4, the terrain (sea/river/railway) data storage area M3 is an area for storing data regarding the ocean, rivers, and railroads for route guidance.

The point (public facility, etc.) data storage area M4 is used for route guidance, such as public I7I! This is an area for storing the current location such as i-crotch.

The character data storage area M5 is for route guidance.
This is an area for storing character display data to T18.

The area name search data storage area M6 is an area for storing area names in units of municipalities for area name searches in route guidance.

Next, the position measurement process of the hybrid position measurement means 1 in the vehicle route guide device having the above configuration will be explained with reference to FIG.

In step 701, it is determined whether the current mode is the departure point mode. The departure point mode is a mode provided for performing semi-advanced procedures at the start of travel, and is distinguished from the mode during travel. Step 701
If it is determined that the mode is the departure point mode, proceed to step 7.
The process proceeds to step 707, and the processing from step 707 onwards will be described later. If it is determined in step 701 that the current mode is not the registration mode (driving mode), the process moves to step 702.

In step 702, the previous current position data (X, Y) is read from the current value register.

In step 703, the map block in which the current position exists is obtained as integer values of X/α and Y/β with reference to FIG.

In step 704, the starting point coordinates (x+, Y+) shown in FIG.
The current position (X
, Y) is searched for.

In step 705, reliability data (1 or O) for the road segment searched in step 704 is read.

In step 706, the reliability data M rlJ or “
The OJ is determined, and if it is "1", it is determined that positioning is possible and the process moves to step 707, but if it is "0", it is determined that sub-use is not possible and the process moves to step 714, where the positioning possible flag is reset. l- and returns to step 701 with an interrupt.

In step 707, it is determined whether it is possible to receive three or more GPSW stars, and if there are fewer than two, it is determined that positioning is not possible and the process moves to step 714, where the positioning possible flag is reset as described above, but if three or more If reception is possible, the process moves to step 708.

In step 708, the current position (
Xo, Ya) is measured, and the DOP value at that time is calculated.

In step 709, it is determined whether the DOP value is 10 or less, and if it is greater than 10, it is determined that the positioning accuracy is poor and the process moves to step 713.

In step 713, it is determined whether the current mode is the departure point zero record mode, and unless it is the departure point registration mode, the process moves to step 714, where the positioning enable flag is reset as described above.

If the departure point mode is determined in step 713 and if it is determined in step 709 that the DOP value is 10 or less, the process moves to step 710.

In step 710, a positioning possible flag is set.

In step 711, the four seedlings of the current value register are processed.

In step 712, the contents of the current value registers (X, Y) are transferred to the screen buffer, the CRT 17 is caused to display the current position, and then the process returns to step 701 with an interrupt.

On the other hand, if the registration mode of the departure point is determined in step 701, the process moves to step 707 (1).In this case, if there are three or more GPS satellites in step 707, DO
Regardless of the P value, the process moves to steps 710 to 712, and the current position is registered even if the accuracy is somewhat poor.

In addition, despite the poor positioning accuracy here, GP
The reason for registering the position determined by S is that the departure point mode is a special mode for registering the departure point, and it is desirable to register the current position here even if the accuracy is somewhat low.

As described above, in this example, the reliability data "1" or rOJ shown in FIG. 6 is searched for each road, and the reliability data "1" or rOJ shown in FIG.
In this case, measure the position using GPS as usual and correct the estimated position.

On the other hand, if the reliability data is "0", step 7
The process moves from step 06 to step 714, where position measurement by GPS is not performed and the estimated position is not corrected.

Therefore, in this example, measurements with unexpected poor accuracy will not be performed, and the estimated position will not be corrected to a position that is significantly deviated due to unexpected radio wave measurement errors.

In the embodiments shown above, the radio wave position measuring device is not shown as a GPS receiver, and the reliability data is defined by the presence or absence of reflection, etc. Depending on the configuration of the position measuring device, the presence or absence or degree of diffraction, noise mixing, and multipath may be specified in consideration of physical properties that affect radio wave position measurement accuracy.

In addition, in this example, the reliability is expressed as a binary value of "1" or rOJ, and when the reliability is rOJ, the estimated position is not corrected, but the reliability may be a continuous numerical value, and the reference value A configuration may also be adopted in which the estimated position is not corrected when the reliability is as follows.

Note that the present invention is not limited to these embodiments, and can be implemented in other embodiments by making appropriate design changes.

[Effects of the Invention] As described above, according to the route guidance device for a vehicle according to the present invention, it is possible to accurately measure the position even when driving on a road where unexpected measurement errors such as reflection or diffraction of radio waves may occur. route guidance can be performed effectively.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an outline of the present invention, Figs. 2 to 7 show an embodiment of the invention, Fig. 2 is a block diagram of a route guide device for a vehicle, and Fig. 3 is a block diagram of a vehicle route guidance device. 4 is a memory map of the external memory, FIG. 5 is a memory map of the road data storage area, FIG. 6 is a data format of road data, and FIG. 7 is a flowchart of position measurement processing. 1...Hybrid position measuring means 2...Route guidance means 3...Reliability data storage means 4...Modification prohibition means Agent Patent attorney Yasuo Miyoshi 11th! !

Claims (1)

[Claims] A hybrid position measuring means that calculates the current position of the vehicle while correcting the estimated position obtained by integrating the unit traveling vector with the position measured by radio waves, and route guidance of the vehicle using the current position measured by the means. a route guidance means for appropriately performing the above-mentioned radio wave reception environment, a reliability data storage means for storing for each road the measurement reliability of the radio wave measurement defined based on the quality of the radio wave reception environment on each road; A vehicular route guidance device comprising: modification prohibition means for searching data and prohibiting the modification when the measurement reliability of the electrical measurement is low.