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BACKGROUND OF THE INVENTION
The present invention relates to a road obstacle monitoring device and more
in detail to a road obstacle monitoring device, in which road obstacles
such as wave flooding, land slip, etc. are detected by means of a
monitoring TV camera; detected image signals are subjected to image
processing and it is judged whether there are road obstacles or not; and
if there are road obstacles, a warning signal is outputted immediately in
order to be able to take measures at sites against the road obstacles and
to give warning to drivers of passing vehicles, etc.
Heretofore, occurrence of this kind of road obstacles is verified often by
a monitoring patrol by monitors or by information by passengers, drivers
of passing vehicles, etc., who are going to pass through a place of the
occurrence, after the road obstacles have really occurred. On the other
hand, depending on the location of the road, suitable detecting sensors
are set before hand to verify the road obstacles by measuring outputs from
the detecting sensors.
Consequently, by the prior art means for detecting the road obstacles as
described above, in the case where the road obstacles take place, they
cannot be verified, until a monitor goes to the place of occurrence for
the monitoring or an informer informs him of the occurrence of the road
obstacles, which causes delay of judgment to be done for securing the
safety for the traffic. Further, depending on the kind of detecting
sensors, there is an undesirable problem that an extremely large number of
detecting sensors are required for effecting measurements and detections
of unspecified road locations and extents of road obstacles.
SUMMARY OF THE INVENTION
The present invention has been done in order to solve such a problem of the
prior art technique and the object thereof is to provide this kind of road
obstacle monitoring devices using an imaging device for monitoring a road
section, where occurrence of obstacles is foreseen, and an image
processing device for processing image signals thus generated as
previously determined in order to be able to measure and detect
automatically obstacles in a sufficiently wide monitoring area with
respect to an individual detecting sensor so as to take measures at sites
at a point of time where the road obstacles take place and to effect
rapidly danger announcement by means of warning boards, etc. for
passengers passing through a location, where the obstacles have taken
place, and drivers of vehicles on the route there.
In order to achieve the above object, a road obstacle monitoring device is
characterized in that it comprises a monitoring imaging section for
monitoring and imaging a road section, where road obstacles by wave
flooding, land slip, etc. are foreseen; an image processing section for
image-processing image signals generated by the monitoring imaging section
to extract component data corresponding to the road obstacles; a measuring
recognizing section for measuring the component data corresponding to the
road obstacles thus extracted to detect the road obstacles from a results
of measurements; and a warning displaying section for displaying a result
of recognition obtained by the measuring recognizing section.
Consequently, owing to the construction as described above, a road obstacle
monitoring device according to the present invention, has following
operations.
That is, a monitoring imaging section monitors and images a road section,
where road obstacles by wave flooding, land slip, etc. are foreseen, to
output image signals; the image signals thus generated are data-processed
by an image processing section so that component data corresponding to the
road obstacles are extracted; and the component data corresponding to the
road obstacles thus extracted are measured by a measuring recognizing
section for measuring the component data corresponding to the road
obstacles thus extracted so that it is detected from a result of
measurements whether there exist the road obstacles or not and a result of
recognition thus obtained is displayed for warning. In this way, it is
possible to inform passengers, drivers of vehicles, etc. passing
therethrough of the road obstacles by wave flooding, land slip, etc. in
the road section to be monitored.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a scheme for explaining a situation, which is a first application
example, in which a road obstacle monitoring device according to the
present invention is applied to a road along a coast, where occurrence of
road obstacles by wave flooding can be foreseen;
FIG. 2 is a block diagram showing the outline of the construction of the
road obstacle monitoring device according to a first embodiment of the
present invention;
FIG. 3 is a block diagram showing an imaging section in detail, which
corresponds to a monitoring TV camera used in the embodiment described
above;
FIG. 4 is a conceptual scheme for explaining a method for measuring wave
height by means of the device used in the embodiment;
FIG. 5 is a scheme for explaining a situation, which is a second
application example, in which a road obstacle monitoring device according
to the present invention is applied to a road constructed at a place
between mountains, surrounding a mountain, where occurrence of road
obstacles by land slip can be foreseen; and
FIG. 6 is a flow chart for explaining a method for measuring obstacles,
which have slipped on a road to be monitored in the application example
described above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a scheme for explaining the first application example of the
present invention. Here it shows schematically a situation, in which a
road obstacle monitoring device is set, as an application example, in the
case where occurrence of road obstacles by wave flooding can be foreseen
in a road along a coast.
In the construction of the first application example indicated in FIG. 1, a
road to be monitored 11 is constructed along a coast; a bank 12 is
constructed on the sea side of the road to be monitored 11; an imaging
device here a monitoring TV camera 13, is secured on a display
construction 16 constructed on a shoulder portion, etc. of the road to be
monitored 11 described above, projecting upward from the road to monitor
and image a wave flooding area 14 having an extent of a certain height
over a certain distance, including the upper part of the bank 12 described
above, without interruption; and a warning display device, here a warning
display board 15, is disposed on a display surface of the display
construction 16 described above and displays a warning against the
occurrence of road obstacles by wave flooding to inform drivers of
vehicles; etc. passing therethrough of danger.
Next, FIG. 2 is a block diagram showing the outline of the construction of
the road obstacle monitoring device according to an embodiment of the
present invention. The device used in this embodiment is composed roughly
of a terminal device A consisting of a monitoring TV camera 13 and the
warning display board 15 and a central device B processing image data
generated on the terminal device A side. These devices A and B are
connected appropriately, e.g. through a communication line, etc.
In the terminal device A having the construction indicated in FIG. 2, an
imaging section 21 corresponds to the monitoring TV camera 13; a
transmission control section 22 controls data transmission and reception
on the terminal device A side; a warning display board section 23
corresponds to the warning display board 15 described above; and a board
control section 24 controls the display on the warning display board
section 23. On the other hand, in the central device B, a transmission
control section 25 controls data transmission and reception on the central
device B side; a monitor section 26 for monitoring displays image data
from the terminal device A described above; an image processing section 27
processes the image data after having A/D-converted them; a measuring
section 28 measures the road obstacles, here obstacles by wave flooding,
by using a result of the processing described above to recognize them; a
display board 29 displays a result of recognition thus obtained; and an
information storing section 30 stores information on the result of
recognition.
FIG. 3 is a block diagram showing the imaging section 21 corresponding to
the monitoring TV camera 13 described above in detail.
In the construction of this imaging section 21 indicated in FIG. 3, an
imaging lens 31 has an auto iris focusing function and 32 represents a
so-called CCD camera, these imaging lens 31 and the CCD camera 32
constituting the monitoring TV camera 13. The control of the iris focusing
function of the imaging lens 13 and the control of the electronic shutter
function of the CCD camera 32 are effected simultaneously by the camera
control section 33 on the basis of control signals from the central device
B described above. These controls in the imaging section 21 are effected
in order to obtain images always with a suitable contrast, corresponding
to variations in the brightness, in the day time and in the night, in the
open air.
Further, FIG. 4 is a conceptual scheme for explaining a method for
measuring the height of waves getting-over the bank 12 by means of the
device used in a first application example, in which h represents the
setting height of the monitoring TV camera 13; l the distance from the TV
camera 13 to the bank 12; .theta. the inclination of the monitoring TV
camera 13 from the horizontal plane; .phi. the angle of visual field in
the vertical direction of the above TV camera 13; and n the vertical
position of a pixel corresponding to the summit of a wave flooding, imaged
by the monitoring TV camera 13, h' indicating the greatest height of the
wave.
Next, the operation of the device of the embodiment having the construction
used in the first application example described above will be explained.
In the construction of the device in this embodiment, as indicated in FIG.
1, the monitoring TV camera 13 on the terminal device A side is set
previously in a region, where wave flooding waves are foreseen. The wave
flooding monitoring area 14 on the road to be monitored 11 are monitored
always and at the same time image data obtained by means of the TV camera
13 for monitoring wave flooding are transmitted from the transmission
control section 22 to the transmission control section 25 on the central
device B side, where the image data in the wave flooding monitoring area
14 transmitted to the central device B side are data-processed at first by
the image processing section 27 so that only component data representing
the wave flooding are extracted. Subsequently, in the measuring section
28, the vertical position of the pixel corresponding to the summit of a
wave flooding, indicated in FIG. 4 is obtained from the extracted
component data representing the wave flooding.
As clearly seen from FIG. 4, the real greatest height of wave h' can be
easily calculated by using a following formula;
##EQU1##
where N represents the number of pixels in the vertical direction in the
used CCD camera 32.
In the case where the greatest wave height h thus calculated exceeds a
dangerous level, a warning signal from the measuring section 28 is
transmitted to the transmission control section 22 on the terminal device
A side through the transmission control section 25. On the terminal device
A side, which has received the warning signal, it is led to the warning
display board section 23 through the board control section 24 and finally
a warning display is effected on the warning display board 15 in order to
give drivers of vehicles, etc. passing through the road to be monitored 11
a warning that there are road obstacles by wave flooding.
Further, even if dangerous wave heights appear only discontinuously in the
obtained image data, it is desirable to hold continuously the display of
the warning against wave flooding for a predetermined setting time so as
to warn passengers of the danger.
Next, FIG. 5 is a scheme for explaining a situation, which is a second
application example, in which a road obstacle monitoring device according
to the present invention is applied to a road constructed at a place
between mountains, surrounding a mountain, where occurrence of road
obstacles by land slip can be foreseen.
In the construction of the second application example indicated in FIG. 5,
a road to be monitored 51 is constructed so as to surround a mountain; a
monitoring TV camera 52 images without interruption a fall monitoring area
53 having an extent of a certain height over a certain distance, where
land slip can be foreseen on the road to be monitored 51; and a warning
display board 54 displays a warning against the occurrence of road
obstacles by land slip to inform drivers of vehicles, etc. passing
therethrough of danger. Further, 55 in the figure represents an obstacle,
which has slipped on the road to be monitored 51.
Here, also in this second application example, the detail of each part of
the device is constructed approximately similarly to the case of the first
application example described previously.
In the construction of the device in this embodiment, as indicated in FIG.
5, the monitoring TV camera 52 is set previously in a region, where land
slip is foreseen. The fall monitoring area 53 on the road to be monitored
51 are monitored always and at the same time image data obtained by means
of the TV camera 52 for monitoring land slip are transmitted from the
transmission control section 22 to the transmission control section 25 on
the central device B side, where the image data in the fall monitoring
area 53 transmitted to the central device B side are
frame-difference-processed at first by the image processing section 27
after having been A/D converted, so that only component data representing
a body on the road to be monitored 51, i.e. in this case body
corresponding the obstacle 55, which has fallen, are extracted.
Thereafter, in the case where there are no variations in the extracted
component data representing the body and in particular in the case where
there are no moving variations, when several frames with an interval of a
predetermined time are processed in a similar way, the measuring section
28 judges that this is an obstacle 55 and transmits a warning signal from
the transmission control section 25 to the transmission control section 22
on the terminal device A side. On the terminal device A side, which has
received the warning signal, it is led to the warning display board
section 23 through the board control section 24 and finally a warning
display is effected on the warning display board 54 in order to give
drivers of vehicles, etc. passing through the road to be monitored 51 a
warning that there are road obstacles by land slip.
FIG. 6 is a flow chart for explaining a method for measuring the obstacles
55, which have slipped on the road to be monitored 51, by the device in
the second application example.
That is, in this FIG. 6, the image data in the fall monitoring area 53
imaged by the fall monitoring TV camera 52 (Step S-60) are written in a
memory as image data a for every frame in the image processing section 27
(Step S-61). Here, at the same time, the difference between the image data
a written for every frame and the image data b preceding them by 1 frame
is obtained by a calculation processing (Step S-62). The body on the road
to be monitored 51 is detected by a result thus obtained (Step S-63).
When the body on the road to be monitored 51 is detected in this way, the
number of repetitions thereof is counted (Step S-64). If the count value
doesn't reach a predetermined value set for the number of repetitions, the
image data b are held as they are (Step S-65). The image data a are
up-dated and the differential calculation is repeatedly effected. In the
case where the body on the road to be monitored 51 is continuously
detected, also when it is repeated a predetermined number of times, it is
judged that the body is an obstacle 55 and a control signal representing
it is transmitted to the measuring section 28 (Step S-66). Thereafter, the
measuring section 28 measures the size of the obstacle 55 and judges
whether it is dangerous or not. If necessary, it outputs a warning signal.
On the contrary, in the case where no body is detected on the road to be
monitored 51 at the point of time of Step S-63 described above, the
counter for the number of repetitions is set at "0" (Step S-67). Then the
image data a is rewritten in the memory for the image data b (Step S-68)
and thereafter imaging is effected again (Step S-60). The memory for the
image data a is up-dated and the differential calculation is effected.
Further, although in the construction of embodiment in each of the
application examples, the monitoring TV camera in the monitoring and
imaging section and the warning display board in the warning display
section are located in a state where they are arranged closely to each
other, contrarily to the fact that the setting position for the former,
i.e. monitoring TV camera, is restricted for monitoring and imaging always
a predetermined extent to be monitored, it is not necessary to restrict
the setting position for the latter, i.e. warning display board, but it
may be located before road obstacles considerably distant therefrom.
As clearly seen from the construction of embodiment in each of the
application examples, since a road obstacle monitoring device comprises a
monitoring image section for monitoring and imaging a road section, where
road obstacles by wave flooding, land slip, etc. are foreseen; an image
processing section for image-processing image signals generated by the
monitoring imaging section to extract component data corresponding to the
road obstacles; a measuring recognizing section for measuring the
component data corresponding to the road obstacles thus extracted to
detect the road obstacles from a result of measurements; and a warning
displaying section for displaying a result of recognition obtained by said
measuring recognizing section, it is possible that a monitoring imaging
section monitors and images a road section, where road obstacles by wave
flooding, land slip, etc. are foreseen, to output image signals; the image
signals thus generated are data-processed by an image processing section
so that component data corresponding to the road obstacles are extracted;
and the component data corresponding to the road obstacles thus extracted
are measured by a measuring recognizing section for measuring the
component data corresponding to the road obstacles thus extracted so that
it is detected from a result of measurements whether there exist the road
obstacles or not and a result of recognition thus obtained is displayed
for warning so as to inform passengers, drivers of vehicles, etc. passing
therethrough of the road obstacles by wave flooding, land slip, etc. in
the road section to be monitored. As the result, an effect can be obtained
that it is possible to inform beforehand passengers, drivers of vehicles,
etc. passing therethrough of the road obstacles such as wave flooding,
land slip, etc. on the road to be monitored to avoid efficiently dangers
at passage accompanied by the road obstacles in order to secure
satisfactorily the safety for the traffic.
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