 |
Description  |
|
|
FIELD OF THE INVENTION
This invention relates to a vehicle traveling guidance system and, more
particularly, to a guidance system including data providing sources laid
on a road surface.
DESCRIPTION OF THE RELATED ART
Various guidance systems have been suggested in order to facilitate driving
operation of a vehicle operator.
For example, traveling control methods and apparatus of an unmanned
conveying vehicle described in Japanese Patent Laid-Open Publication No.
Hei 1-253007, include allowing an unmanned conveying vehicle to travel
along a road by laying magnetic markers at fixed points on a traveling
track, detecting the magnetic field strength of these magnetic markers
with a magnetic field detector, and controlling the vehicle so that a
shift of the vehicle in relation to the road becomes smaller.
However, in order to accurately detect a shift of a vehicle in relation to
a road, a large number of magnetic markers must be laid at short
intervals. This causes the problems of extensive laying work and resulting
high cost.
In a related application, Japanese Patent Application No. Hei 7-157878, the
applicant of this application therefore taught suggested a configuration
where magnetic generating means laid on a road surface provide a vehicle
with data on the shape of the road surface. This configuration enables
sure guidance of a vehicle without requiring the number of magnetic
generating means laid at short intervals of the related art because a
vehicle can recognize the shape of a road surface on which it is planning
to travel in advance.
Even in this related art, however, the basic function of the magnetic
generating means is limited to the provision of data on the shape of a
road surface; it is difficult for the magnetic generating means to send a
vehicle proper data for guidance according to traffic conditions changing
every hour. Smoother guidance taking into consideration the flow of
traffic was limited.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system which enables
proper guidance of a vehicle according to traffic conditions.
In order to achieve the above object, a vehicle traveling guidance system
according to the present invention comprises a data providing device laid
on a road and a vehicle, wherein a vehicle includes a data transmitter for
sending a data providing device traveling data of the vehicle when the
vehicle passes over the vicinity of the data providing device and a data
receiver for receiving data sent from the data providing device. The data
providing device includes a receiver for receiving the traveling data and
a transmitter for sending other passing vehicles the traveling data. The
data providing device not only sends data concerning the shape of the
road, but also receives traveling data on a passing vehicle and sends this
traveling data to other passing vehicles. Therefore, a vehicle operator
can gain knowledge of the traveling state of a vehicle which has already
passed over that point and adjust travel considering traffic flow.
In this case it is preferable that the data providing device should be an
electronic wave tag laid on a road surface. Also, it is preferable that
the traveling data should include vehicle pass time or vehicle pass time
and speed. Furthermore, it is preferable that the number of data providing
devices laid on a road should be greater than one and that there should be
a control center for communicating through the data providing devices to a
passing vehicle traffic data obtained from traveling data sent from each
of the data providing devices. It is preferable that the control center
should predict the occurrence of traffic congestion based on the pass time
and speed of a vehicle included in the traveling data and communicate the
occurrence of traffic congestion as the traffic data. It is assumed that
at a certain point, vehicles were traveling smoothly at a certain time and
the speed of each vehicle has decreased drastically at the next time. In
this case it is expected that traffic congestion will occur in the
vicinity of that point. Therefore, smooth travel can be achieved by, for
example, communicating to each vehicle data etc. indicating bypasses in
order not to worsen traffic congestion.
Furthermore, in order to achieve the above object, a vehicle traveling
guidance system according to the present invention comprises a data
providing device laid on a road, wherein the data providing devices
include a detector for detecting a traveling state of a vehicle passing
over the vicinity thereof and a transmitter for sending the traveling
state detected to other passing vehicles and a vehicle includes a receiver
for receiving data sent from the data providing device. The data providing
device itself detects the traveling state of a passing vehicle, and so
vehicles without transmitters may be used in this system.
In this case it is preferable that the data providing device should detect
the pass time of a vehicle and that the transmitter should send the
traveling state and the pass time. Also, it is preferable that the number
of the data providing devices laid on a road should be greater than one
and that there should be a control center for communicating, through the
data providing devices, to a passing vehicle traffic data obtained from
traveling data sent from each of the data providing devices. It is
preferable that the control center should predict the occurrence of
traffic congestion based on the pass time and speed of a vehicle included
in the traveling data and communicate the occurrence of traffic congestion
as the traffic data.
Furthermore, in order to achieve the above object, a vehicle traveling
guidance system according to the present invention comprises a memory laid
on a road for storing traveling data on a passing vehicle and a
transmitter laid on the road for sending the traveling data to a next
passing vehicle. Each vehicle can control its traveling based of traveling
data of the preceding vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a configuration of a vehicle of embodiment 1.
FIG. 2 is a block diagram of a configuration of an electronic wave tag of
embodiment 1.
FIG. 3 is a block diagram of a configuration of an electronic wave tag of
embodiment 2.
FIG. 4 is a view showing a configuration of embodiment 3.
FIG. 5 is a view showing a state at a certain time after the time of FIG. 4
.
DESCRIPTION OF THE EMBODIMENTS
Based on the drawings, embodiments according to the present invention will
be described below with an electronic wave tag laid on a road surface as
an example of a data providing source.
Embodiment 1
FIGS. 1 and 2 show a system configuration of embodiment 1: FIG. 1 is a
block diagram of a configuration of a vehicle, while FIG. 2 is a block
diagram of a configuration of an electronic wave tag laid on a road
surface. The basic configuration of the road surface is the same as that
described in Japanese Patent Application No. Hei 7-157878, a related
application. That is, electronic wave tags are laid on a road surface at
fixed intervals (for example, 100 m) for sending data on the shape of the
road surface to a passing vehicle, and a pair of magnetic markers is laid
on the road surface at the side of each electronic wave tag from which a
vehicle would approach. A vehicle recognizes its relative position
(displacement) to the road surface by detecting the presence of magnetic
markers, obtains data on the shape of the road surface from the electronic
wave tag while controlling steering, and controls steering according to
the shape of the road surface in intervals where no magnetic markers
exist.
At the rear of a vehicle of FIG. 1, there are an electronic wave receiver
11 for receiving electronic waves from an electronic wave tag, a
demodulating section 12 for demodulating electronic waves received by the
electronic wave receiver 11, a received data memory (RAM) 13 for storing
data demodulated by the demodulating section 12, and a magnetic sensor 14
for detecting magnetic markers laid on a road surface with an electronic
wave tag. Received data stored in the RAM 13 and magnetic data detected by
the magnetic sensor 14 are provided to a controller 21 comprising
microcomputers.
Also, at the front of the vehicle of FIG. 1, there are a transmitted data
memory (RAM) 31 for storing data from the controller 21; a modulating
section 32 for modulating transmitted data; an electronic wave transmitter
33 for sending modulated data to an electronic wave tag; a magnetic sensor
34 for detecting, as with the magnetic sensor 14 at the rear of the
vehicle, magnetic markers laid on a road surface; a magnetic field
generator 35 for generating a magnetic field as driving power of an
electronic wave tag; a standard time clock 41 for detecting when the
vehicle passed over an electronic wave tag; and a GPS receiver 42 for
obtaining a reference time used to calibrate the standard time clock 41.
The calibration of the standard time clock 41 may also be performed by a
reference time obtained by a receiver for receiving a standard-frequency
signal such as JJY. When the magnetic sensor 14 detects a magnetic marker
on a road surface, the magnetic field generator 35 is excited at an
instruction from the controller 21. An electronic wave tag obtains desired
power from a resulting magnetic field by the magnetic field generator 35
and a special power supply is therefore not necessary for the electronic
wave tag. An electronic wave tag starts only when a vehicle passes over
it. Also, data on a standard time calibrated by a reference time from the
GPS receiver 42 is stored in the transmitted data memory 31 and is sent,
together with traveling data such as the speed and ID of a vehicle, to an
electronic wave tag. Sending of data is performed either after the
magnetic sensor 14 detects a magnetic marker and the magnetic field
generator 35 generates a magnetic field, or with the generation of a
magnetic field after the magnetic sensor 14 detecting a magnetic marker.
FIG. 2 shows a configuration of an electronic wave tag 60. The
communication system comprises an electronic wave receiver 61 for
receiving traveling data (ID, speed, and pass time) sent from a passing
vehicle, a demodulating section 62 for demodulating received data, a data
memory (RAM) 63 for storing demodulated data, a transmitted data ROM 71
for storing transmitted data, a modulating section 72 for modulating
traveling data from the data memory (RAM) 63 and data output from the
transmitted data ROM 71 into traveling data to be transmitted, an
electronic wave transmitter 73 for sending traveling data to a passing
vehicle, and a controller 81 for controlling the above sending and
receiving. The power system comprises a magnetic field detector 91 for
detecting a magnetic field generated by the magnetic field generator 35 of
a vehicle, a power conversion section 92 including a coil for converting a
detected magnetic field into power with electromagnetic induction, and a
back-up power supply 93 for providing power, in case of necessity, to the
power conversion section 92 and storing power. A solar battery 94 for
converting, in case of necessity, the sunlight or incident light into
electric energy may be used. When power obtained in the power conversion
section 92 is provided to the controller 81, control operations begin.
Traveling data sent from a vehicle is received and stored in the data
memory (RAM) 63. After the data is received, traveling data on the
preceding vehicle already stored in the RAM is sent to the passing
vehicle. The traveling data to be sent includes the ID, speed, and pass
time of the preceding vehicle, and information on the electronic wave tag
(for example, location data) stored in the transmitted data ROM 71.
In the above configuration, sending and receiving data in the case of a
vehicle passing over the vicinity of an electronic wave tag is performed
in the following way. That is, when the magnetic sensor 14 mounted on the
vehicle detects a magnetic marker just on this side of the electronic wave
tag, the controller 21 causes the magnetic field generator 35 to start in
order to provide a magnetic field to the electronic wave tag and causes
the electronic wave transmitter 33 to send the ID, speed, and time data on
the vehicle to the electronic wave tag. In the electronic wave tag, the
magnetic field detector 91 detects a magnetic field and power, with
supplementary power coming from the back-up power supply 93, is provided
to each section. With the power supply as a trigger, the controller 81
causes the RAM to store ID, speed, and pass time data of the vehicle from
the electronic wave receiver 61. Also, the ID, speed, and pass time data
of the preceding vehicle stored in the data RAM 63 is sent to the vehicle
through the electronic wave transmitter 73. In the vehicle data sent from
the electronic wave tag is received by the electronic wave receiver 11 and
is provided to the controller 21. The controller 21 controls the traveling
of the vehicle based on the received data.
A vehicle passing over an electronic wave tag can receive speed and pass
time data of the preceding vehicle in this way, and so can recognize a
traveling state of the preceding vehicle. Based on this data, the current
vehicle can then determine whether it is traveling properly. This data is
especially helpful when the preceding vehicle cannot be seen because of
bad weather or a curves in a road. Assuming that a great deal of time has
not elapsed since the preceding vehicle passed and that the speed of the
preceding vehicle is slower than that of the current vehicle, slowing down
the speed of the current vehicle is one of method for maintaining the
distance between vehicles.
The back-up power supply 93 may consist of secondary cells or
supercapacitors (compact capacitors having large capacitance), which
enables it to function as a power supply for holding and driving the data
RAM 63 until more than one vehicle passes. By connecting the solar battery
94 to the power conversion section 92, power supply will not break down if
the sunlight or light irradiated from an adequate light source can be
obtained. Power supply from the solar battery 94 may fail. However, should
no vehicle pass for a long enough time for power stored in the back-up
power supply 93 to be used up, it would mean that traffic is extremely
light and that there is therefore no need for vehicle guidance to consider
the distance between vehicles; the effectiveness of this system would not
be reduced. In this case, the controller 81 sends a passing vehicle only
data stored in the transmitted data ROM 71.
Furthermore, according to a configuration of this embodiment, sending and
receiving data between a vehicle and an electronic wave tag is performed
with electronic waves. However, data sending and receiving may be
performed by optical communication devices using optical signals, such as
infrared rays.
Furthermore, according to a configuration of this embodiment, power is
provided to an electronic wave tag by generating a magnetic field with the
magnetic field generator 35 mounted on a vehicle. However, power may be
provided with light by mounting a floodlight projector on a vehicle and a
photo-electric converting device on an electronic wave tag.
Embodiment 2
FIG. 3 shows a configuration of embodiment 2. The above embodiment 1
assumed that the transmitter for providing traveling data on a vehicle to
an electronic wave tag is mounted on a vehicle. Considering the usual
traffic, however, there will exist both vehicles with a transmitter and
vehicles without a transmitter. Therefore, this embodiment shows a
configuration in which traffic data can be also provided surely to a
vehicle without a transmitter.
In FIG. 3, a vehicle 100 traveling an area between lane lines 101 and 102
is not equipped with the electronic wave transmitter 33 shown in FIG. 1.
As in FIG. 2, an electronic wave tag is equipped with an electronic wave
transmitter and receiver, but an electronic wave transmitter 173 according
to this embodiment also sends radar electronic waves for detecting the
speed of the vehicle 100. It may send the radar electronic waves, either
all the time or only when a passing vehicle is detected in some way. An
electronic wave receiver 191 receives radar electronic waves reflected
from the vehicle 100. The reflected radar electronic waves, received by
the electronic wave receiver 191 are demodulated by a demodulating section
192 and are provided to a controller 181 in order to detect the speed of a
passing vehicle. Speed may be detected using, for example, the Doppler
effect. The electronic wave tag is also equipped with an internal clock
(not shown) for measuring the time when reflected radar electronic waves
are received. This corresponds to the pass time of a vehicle. The pass
time, time elapsing after the pass of the preceding vehicle may be
measured. The speed and pass time data detected is stored in a data RAM
163. Traveling data on the preceding vehicle (vehicle which passed just
prior to a passing vehicle) already stored in the data RAM 163 is
modulated by a modulating section 172 and then sent from the electronic
wave transmitter 173 to the vehicle currently passing over the electronic
wave tag. Traveling data on the vehicle currently passing over the
electronic wave tag newly stored in the data RAM 163 is sent to the
succeeding vehicle (vehicle which will pass after the passing vehicle).
Even if a vehicle has no transmitter, as described above, this embodiment
enables an electronic wave tag itself to obtain the speed and pass time
data on a passing vehicle and to provide it to the succeeding vehicle.
Even with the usual traffic including various vehicles, therefore, smooth
vehicle guidance can be achieved.
An internal clock in an electronic wave tag can be calibrated each time a
vehicle with a transmitter passes over the electronic wave tag. In this
case, pass time data sent from a vehicle is used. This method improves
accuracy.
Embodiment 3
FIGS. 4 and 5 show a system configuration of embodiment 3. FIG. 4 is a view
showing a case where a preceding vehicle 210 passes over the vicinity of
an electronic wave tag 200 and FIG. 5 is a view showing a case where a
succeeding vehicle 220 reaches the same point. FIGS. 4 and 5, include
communication equipment 300, including a beacon and a communication
antenna, on the side of a road for receiving electronic waves from the
electronic wave tag 200. A control center (monitor center) 310 is
connected to the communication equipment 300 by wire or wireless for
collecting the ID, speed, and pass time data of a passing vehicle sent
from each of the electronic wave tags 200. That is, the electronic wave
tag 200 of this embodiment has a function to send traveling data on a
passing vehicle, not only to a vehicle passing next but also to the
communication equipment 300 (an electronic wave transmitter in FIG. 2 or 3
can have this function) and the control center 310 can perform batch
processing of data collected from the electronic wave tag 200.
In FIG. 4, when the preceding vehicle 210 reaches a point near the approach
side of the electronic wave tag 200, traveling data on the preceding
vehicle 210 is sent from the vehicle to the electronic wave tag 200, as
shown in embodiment 1. After receiving traveling data, the electronic wave
tag 200 stores it in a data RAM and sends the traveling data of the
preceding vehicle 210 to the succeeding vehicle 220, as shown in FIG. 5.
Also, the electronic wave tag 200 sends the traveling data on the
preceding vehicle 210 to the communication equipment 300, which then sends
the traveling data to the control center 310. Based on the speed and pass
time data from each electronic wave tag, the control center 310 recognizes
the flow of traffic at each point and sends each electronic wave tag data
on traffic information at that point. The electronic wave tag 200 having
received data on traffic information from the control center 310 sends
this data, together with traveling data, to passing vehicles. The data on
traffic information includes data on the presence of a damaged vehicle,
occurrence of an accident, congestion information, points where traffic
congestion is likely to occur from now on, and the like. The following is
an example of how congestion is predicted. All the speed and pass time
data of a vehicle at each point where an electronic wave tag exists is
sent to the control center 310. Therefore, if there is a point where at a
certain time the traffic was flowing smoothly and, subsequently, each
vehicle slows down while the intervals between vehicle pass times also
tend to become shorter, this point can be identified as a congestion
point. At this point, even if traffic congestion has not yet occurred, it
is considered likely to occur soon. Therefore, congestion prediction data
is provided to the electronic wave tags 200 on the approach side of that
point from the direction in which vehicles are traveling. Furthermore, the
electronic wave tags 200 having received this data send it to passing
vehicles, which enables each passing vehicle to predict the occurrence of
congestion and to take measures, such as selecting a bypass or decreasing
speed.
Data on traffic information may be related to a more limited area. It is
assumed that more than one vehicle (for example, three vehicles) is
traveling with relatively short distances between them. When the speed of
the third vehicle is greater than that of the first or second, the third
vehicle may overtake the second. In this case, the control center 310
provides data indicating this to the electronic wave tags 200 over which
the second vehicle will pass. This enables the second vehicle to recognize
that the succeeding vehicle will overtake it. Information on changing
lanes based on detecting signals from a lane line deviation detector
separately laid on the side of a road may also be added as the data on
traffic information.
Currently, a system in which various types of data is communicated to a
vehicle from a control center is known. In this embodiment, however,
traffic flow is understand based on the speed data and pass time of a
passing vehicle at each point where an electronic wave tag is laid.
Therefore, a system according to this embodiment differs greatly from a
conventional one in that it can recognize the distance between vehicles at
each point and recognize changes our time. Even if the speed of each
vehicle is reduced, traffic congestion will not occur when there is an
adequate distance between vehicles. That is, congestion prediction with
high accuracy can be achieved by considering both the speed and the pass
time of a vehicle, as in this embodiment.
The embodiments according to the present invention have been described with
the method of using an electronic wave tag laid on a road surface as an
example, but a data transmitter-receiver other than an electronic wave tag
may be laid on a road surface or on the side of a road.
According to the present invention, as described above, traffic information
changing every hour can be provided more precisely to each vehicle
traveling on a road surface. As a result, each vehicle can travel more
smoothly with this traffic information.
While what has been described are, at present, considered to be preferred
embodiments of the invention, it will be understood that various
modifications may be made thereto, and it is intended that the appended
claims cover all such modifications falling within the true spirit and
scope of the invention.
* * * * *
|
|
 |
|
 |
Description |
|
