JPH0536735B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a position detection device for a motor vehicle that detects the target position of a motor vehicle while the motor vehicle is running.

Prior Art Conventionally, in order to guide a car to an unknown destination when driving in an unfamiliar area, mobile radio using the car as a mobile station is used to communicate exclusively with the fixed station of the destination. After confirming the location of the communication partner through conversation, the fixed station gives guidance instructions to the mobile station, but this communication is extremely complicated and there are many factors that can lead to misunderstandings by the person communicating. It has become a thing.

Recently, it has been installed in automobiles to calculate the vehicle's position on two-dimensional coordinates moment by moment while detecting the distance traveled from the starting point and changes in direction as the vehicle travels. An inertial navigation device has been developed that uses an independent system to display the current location on a display screen on which a local road map is set. There is no particular problem if the current position is known, but if it is not, the current position cannot be smoothly guided to the destination only by displaying the current position.

Purpose The present invention was made in consideration of the above points, and
A position detection device for a car is capable of detecting the destination position while the car is running and displaying the detected destination position together with the current position of the own car on the screen of a display device on which a map is set in advance. This is what we provide.

Configuration The automotive position finding device according to the present invention includes an inertial navigation device that constantly determines the current location of the vehicle, and a direction finding device that detects the arrival direction of radio waves sent from a fixed station at the destination. Equipped with
As shown in the figure, the direction of arrival of the radio waves from the fixed station is detected at at least two points A and B during the trip, and from point C where the direction lines D1 and D2 intersect,
The position of the target fixed station is calculated by using the current position of the vehicle at point B at the time of direction finding as a reference.

FIG. 2 shows an embodiment of the automotive position detection device according to the present invention, in which a directional antenna 1 is horizontally rotated 360 degrees by a drive system (not shown), and an electric field is detected while a directional sensor 2 detects the direction of the antenna. The measurement receiver 3 selectively receives radio waves sent from a fixed station according to their communication frequency, and the direction detection circuit 4 fixes the direction of the antenna from when the field strength of the received radio waves reaches its maximum. A direction finding device 5 that determines the direction of the station (relative to the direction in which the vehicle is traveling), an inertial navigation device 6 that continually determines the current position and traveling direction of the vehicle on two-dimensional coordinates, and the determined current position. The absolute direction of the fixed station on the same coordinate plane is determined from the direction detection signal sent from the direction detection circuit 4 based on the position and traveling direction, and the fixed station similarly determined when the vehicle moves to another position. A signal processing unit (CPU) 7 calculates the position of the intersection with the absolute direction of It is comprised of a display 8 that displays marks on the screen along with the current location and direction of travel of the vehicle.

Further, as the electric field measurement receiver 3, a third
As shown in the figure, the received signal of the directional antenna 1 is sent through a tuning circuit 31 to a mixing circuit 32, where it is mixed with a frequency signal from a local oscillation circuit 33 and amplified by an intermediate frequency amplification circuit 34, and the amplified signal is The linear detection circuit 35 is configured to perform detection and output a signal corresponding to the electric field strength of the received signal.

Furthermore, as shown in FIG.
and a direction detector 62 consisting of a rate type sensor (for example, a gas rate sensor, a gyroscope, etc.) that detects changes in direction due to the movement.
The current position and traveling direction detection circuit 63 calculates the current position on the two-dimensional coordinates every moment according to the outputs of these detectors 61 and 62, and determines the current traveling direction. ing. It goes without saying that the current position and traveling direction detection circuit 63 may not be provided in particular, and the signal processing device 7 may have the function thereof.

The operation of the automobile position detection device according to the present invention configured as described above will be explained below.

First, when the car starts traveling, a starting point is set on the screen by appropriate means such as cursor designation in accordance with the map that has been set in advance on the screen of the display 8, and then when the vehicle starts traveling, One pulse signal is given from the distance detector 61 in the inertial navigation device 6 to the current position and traveling direction detection circuit 63 for each unit distance traveled, and by counting the number of pulses, the traveling distance is measured, and the direction is detected. The output of the device 62 is applied to a current position and direction of travel detection circuit 63 to successively determine the direction of travel of the vehicle. The current position and traveling direction detection circuit 63 detects the X-Y position according to the scale of the map set on the screen of the display 8 based on the determined travel distance and direction change of the vehicle.
The current position (x, y) on the coordinates is calculated moment by moment, and the data on the current position thus calculated is given to the signal processing device 7 along with the data on the current direction of movement. The signal processing device 7 stores and stores the given data regarding the current position and traveling direction of the vehicle in an internal memory while updating the data sequentially.

In addition, at two locations during the vehicle's journey, the vehicle issues a radio wave transmission request to a fixed station using a mobile phone or the like, and in response, the direction finding device 5 detects the arrival direction of the radio waves sent from the fixed station.
The detection results are provided to the signal processing device 7.

In the signal processing device 7, as described above, the intersection points of the direction lines of each detected fixed station are determined, and based on the current position of the vehicle at the time of the second direction finding, The absolute position (x'.y'} of the fixed station is determined at , and the data of the determined position is stored and held in the internal memory.

Based on the fixed station position data stored in the internal memory of the signal processing device 7, as well as the vehicle's current position and traveling direction data, the screen of the display 8 is displayed as shown in FIG. By simultaneously displaying marks in different display formats for the vehicle's current position a, traveling direction b, and the absolute position of the fixed station c, it is possible to display the vehicle's current position a, the traveling direction b, and the absolute position of the fixed station c at the same time. It is possible to clearly understand the driving situation, such as the current positional relationship of the car and the direction in which it is currently moving, and it can also be used when temporarily parking while guiding the car to the destination. Even after the display screen has been turned off, the display screen can be regenerated according to the stored data when restarting the vehicle. The map can be set by setting a map sheet on which a predetermined map is drawn on a transparent material prepared in advance on the display screen, or by setting the map sheet based on map data stored in a memory device in advance.
Appropriate measures may be taken, such as displaying a predetermined map on the CRT screen.

In the present invention, if the location of the fixed station is known, the location of the fixed station on the map is specified in advance by a cassole specifying means or the like, and the data of that location is stored in the signal processing device 7. Ok,
It is also possible to calculate the error in the current position of the vehicle from the difference from the fixed station position detected as described above, and to correct the position.

Effects As described above, in the case of the automobile position detection device according to the present invention, when the automobile is traveling in an unfamiliar area,
During the journey, the location of the destination is detected and the location of the destination is displayed on the map of the area where the vehicle is scheduled to travel, which is set in advance on the screen, along with the vehicle's current location and direction of travel, using individual marks with different display formats. The display content makes it possible to confirm the location of the destination on the map with good visibility, and also ensures that the vehicle is guided to the destination according to the map. It has the excellent advantage of being able to

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle for detecting the position of a fixed station, Fig. 2 is a block configuration diagram showing an embodiment of the present invention, and Fig. 3 is a configuration of an electric field measuring receiver in the same embodiment. FIG. 4 is a block diagram showing an example of the configuration of the inertial navigation device in the same embodiment, and FIG. 5 is a diagram showing an example of the display state on the screen of the display device. 1...Directional antenna, 2...Directional direction sensor, 3
...Electric field measurement receiver, 4. Direction detection circuit, 5. Direction finding device, 6. Inertial navigation device, 7. Signal processing device, 8. Display device.

Claims (1)

[Claims] 1. A means for detecting the arrival direction of radio waves from a fixed station, which is a relative direction to the direction of travel of the vehicle, as the vehicle travels, and a means for continually determining the current position and direction of travel on two-dimensional coordinates as the vehicle travels. means for storing and storing each data of the determined current position and traveling direction while sequentially updating the data, and a means for storing and storing each data of the determined current position and traveling direction; From the direction, calculate the absolute direction of the fixed station on the same coordinates, calculate the position of the fixed station at the intersection of each of the calculated absolute directions, and store and store the data of that position. The current position and direction of movement of the vehicle and the position of the fixed station are displayed on a screen on which a map is projected in advance, using individual marks with different display formats, according to the stored data. A vehicle position detection device comprising display means.