JPS63132400A - Automatic traffic flow observing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention is designed to prevent passing cars, etc. ■Traffic volume by vehicle type ■Traveling speed ■Vehicle headway time interval (front axle passing time difference) ■Distance between vehicles (distance between the rear axle of the preceding vehicle and the front axle of the following vehicle) ■Vehicle center passing position ■Wheel center passing position 0 weight This invention relates to an automatic traffic flow observation device that detects medium-term blueprints such as the following.

<Conventional technology and its problems> At present, there is very little data regarding vehicle loads, partly because it is difficult to measure them. Therefore, even as we move toward probabilistic reliability design and critical state design methods, there is still a lack of data regarding loads. Furthermore, when checking the fatigue safety of concrete slabs, floor assemblies, etc., the lack of data regarding loads is still a problem. In the future, when developing a design system for structures and systematizing maintenance and management methods for structures, consideration should be given to the area where the structure is located, the type of road, the characteristics of traffic flow, etc. It is predicted that there will be a time when it will be essential to understand the live load applied. However, even though f1 loads do not occur extremely rarely, such as in earthquakes or strong winds, there is very little data on vehicle loads due to the difficulty of measuring them. Another major cause is the high cost of measurement. Most conventional measurement methods are necessarily too labor-intensive and require large amounts of money (particularly human rights costs) to obtain large amounts of data. In addition, even if a large amount of money was invested, the data was treated as special data from a certain point, and because it was a human-based method, there were always measurement errors, which often led to a loss of motivation for research. Hereinafter, typical measuring methods that have been conventionally performed will be specifically explained.

What is shown in FIG. 7 is a mark for measuring the passing position of the wheel. That is, marks (c) are placed in blocks (b) every 30 cm on an imaginary line that crosses the inside of the vehicle 1a (a) on the roadway. This mark (C) provides a measurement reference for vehicles passing over it.

This method was once implemented at the Public Works Research Institute, and has since been used in many fields. This measurement involves photographing a vehicle traveling on a traffic lane from above a structure crossing the road, such as a pedestrian bridge, using an 8 mm camera or video camera, and processing the photograph manually. This requires a considerable amount of effort, and since the measurement positions are limited, it is difficult to collect a large amount of data. (From literature *I)
FIG. 8 shows another measurement method. , 1111 The measuring staff (d) judges the vehicle type of the vehicle passing the fixed line and presses the switches (I to H) in the switch box (e) shown in Figure 9, and the voltage for each vehicle type is output to the data recorder. and recorded. The vehicle type and headway distance can be determined from the signal when the front axle of the vehicle passes. - Traveling speed can be determined from the time required between the blade side fixed line (') and (g).Manpower is required at the measurement site, and data processing was difficult at that time (7
~8 years ago), I transferred the records in the data recorder to an oscilloscope, applied a scale to read the length, punched the numbers onto a card, and processed them using a computer. We performed 24-hour measurements with 30-minute measurements and 30-minute breaks, but it was a lot of effort.

(From literature *2) Figure 10 shows another method. This uses an ultrasonic pulse reflection type vehicle detector (i) which is often used on various roads. Large vehicles (D) and small vehicles (Ic) can be distinguished based on whether the pulse reflection is fast or slow, and the average running speed can also be determined based on the length of the reflected pulse.However,
Average vehicle length (large vehicle 8.2m.

Since this is a back calculation using a small car (4.97m), the accuracy is poor. (Reference *3) Figure 11 shows yet another method. This figure is a schematic diagram of wheel load and axle measurements. This method uses an axle load meter (n) installed at a toll gate (ei) to determine the wheel load and axle load. Then, the vehicle type and axle load at that time are recorded in the data recorder (no.
The figure is a schematic diagram of wheel load measurement, and Figure 13 is a schematic diagram of vehicle length measurement.) (o) is a signalized intersection, (p) is a restricted section, (r
) is the loading plate, and (8°) is the marker. FIG. 14 shows a flowchart of the data organization. At this stage, the axle load meter C%
) There is no other way to find out the weight using the toll gate (m
) Several measurement personnel (s) are required nearby, and furthermore, A-D conversion is required during data processing, which requires a large amount of labor and cost. (From literature *3) Fig. 15 shows a conventional example of yet another measurement method.

A light source switch (u) is provided across the road from the light emitting device (1) to receive the light beam from the light emitting device W (L).

This device is a vehicle identification device that determines the lane (V) in which the vehicle is passing based on the difference in time between light interruptions, determines the length of the vehicle from the interruption time and traveling speed, and determines the type of vehicle.

The method using this device also requires A-D conversion, and data processing requires great effort and cost. Also, this method must be used only when traffic volume is low.
It cannot be used when vehicles are running in parallel.

(From literature *4) In addition to the above-mentioned methods, another way to determine the vehicle type, inter-vehicle distance, and traveling speed during traffic congestion is to take a photo from the top of a tall building.
There are things to do. In this case, it is necessary to take a photograph during the daytime, and it takes a great deal of effort to read the photograph.

This method was implemented on a large scale by the Ministry of Construction at 75 locations in 1971.

(From literature *3) "Reference *1: Ministry of Construction Civil Engineering Research Institute 2 Study on Design Live Load - Actual status of traffic loads and application to bridge design, Public Works Research Institute Material 70
No. 1, November 1971 *2: Kajikawa; Consideration on usability analysis of road bridges considering vibration sensation, Journal of Japan Society of Civil Engineers, No. 304, December 1980 *3: HLD Committee; 2nd edition, Live Load Subcommittee: Survey of live load conditions on the Hanshin Expressway and analysis for load evaluation *4: Takenouchi, Yomoto, Furukawa, Miki; Method for measuring stress and deformation of bridges due to actual traffic loads.'' The aim is to take into account the problems of the past and to solve them.

<Means for Solving the Problems> Accordingly, the present invention provides at least two load sensors arranged on the road surface so as to intersect with the traffic direction at a predetermined interval, and at least one of the load sensors extends in the longitudinal direction. The present invention aims to provide an automatic traffic flow observation device characterized by being divided into blocks and constituted by individual unit sensors in charge of each block.

Effect> In the present invention having the above means, it is possible to automatically read the vehicle passing times at at least two fixed points,
When a vehicle passes at least one of the road surfaces, various information can be obtained about the passing position of the point of application of the load applied to the road surface.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, shapes, materials, numbers, and relative positions of the component parts described in this example are particularly limited to ("limited to ~ cm", "limited to ~ pieces").
Unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto, and these are merely illustrative examples.

FIG. 1 shows an embodiment of the present invention. Mud switch (1) arranged on the traffic road surface (in this implementation, - as an example, Pridgestone ring CS M 800X 7X 7200
I'll put it up. ) has a code switch (10) embedded inside to detect when a load is applied. To give a detailed example, two code switches (1o) are embedded in neoprene rubber with a thickness of 7.5 ms at appropriate intervals in the direction across the road, one for a speed detection trigger and one for a backup. These two cord switches (10
) is a cord switch with a length of about 5ce (10°).
72 pieces are embedded at approximately 10 cm intervals (of course, this number and spacing is not limited to this). Mad switch (
For fixing to the road surface in step 1), double-sided adhesive tape (for example, #610 manufactured by Tsukisui Kagaku Kogyo KK) may be used (if there is any other suitable fixing method, it may be used for fixing).

FIG. 2 shows an example of the code switch (10).

This uses a pressurized conductive rubber (11) (silicon rubber and metal particles) made by Prigistone as a switch element, and a flat braided wire (12) is constructed in parallel through this, and the outside is covered with silicone rubber (13). It is what was done. Of course, it is also possible to use a sensor based on another method as long as the load sensor can detect the load.

A data logging device (2) detects the raw data obtained from the mud switch (L). This data logging device (
2) (In this example, Kanazawa Control Instruments D L
I'll list -2000. ), when the speed detection trigger switch (10") of the mud switch (1) is turned "ON", the instant time t1 is recorded, and when the main stop switch is turned "ON", that time is recorded. , are recorded. And mad switch (1)
When the tires of the vehicle passing above leave the main stop switch and all of them turn OFF, the 72 switches (10 degrees) change from 0N-OFF to 0-L (binary).
Recorded as data. And the main switch is °O
At time t, when the trigger switch (11") reached "N" (3 bytes).

The time difference between the time 1+ when the main stop switch turned ON and the time t when the main stop switch turned ON is t t-t + (2
Hyde), 7211alno0-1chi'l (9 bytes) are written to the RAM, and the processing for one axis is completed. Then, it enters a state where it waits for the next trigger signal. It takes 1.33 msec to process this -axis. If the vehicle is traveling at 30 m/s, it will end after traveling approximately 4 cm.

For reference, the accuracy of the time counter in this example is 2-1! '5ec (1/32768 second), this precision is used for speed detection, and 211sec (1/32768 second), which is 16 times that precision, is used for elapsed time due to the memory used.
/204g) is used. And 16 in RAM
If a kB one is used, data for about 1100 axes can be recorded.

FIG. 3 shows an example of the overall system configuration. A mud switch (1) is placed on the road surface. A data logging device (2) detects the raw data of this mud switch (1).

Since there are many problems in parking the measurement vehicle near the measurement point, this embodiment is configured to park the measurement vehicle in a remote location and perform the measurement. Of course, the method is not limited to the method of this embodiment (if local conditions permit, measurement may be performed near the measurement point). In this example, a highly reliable optical cable (5) was used to transfer data to a remote location. In this case, a data transfer device (3) consisting of an RS 232C optical modem (4) was used. Currently, we are using Loom for optical cable (5), but
son-ioo.

It can be extended up to about m. Note that data transfer requires a time of 0.1 seconds/axis when the baud rate is 2400 bps. Also, a CPIB may be prepared for short-distance transfer. The data stored in the RAM of the data logging device (2) is temporarily stored in the main storage device of the host computer (6) via the data transfer device (3) according to a control command from the host computer (6). . When the host computer (6) confirms the completion of the transfer, it immediately sends a restart command to the data logging device (2), and then writes the data to the computer's auxiliary storage device (7) (floppy, fixed disk, etc.). After the writing is completed, the postcomputer (6) returns to the state immediately before the data transfer.

At this time, if data processing is in progress, it returns to the original state and continues data processing, and if it is waiting for data transfer, it enters the data transfer state.

The program may be programmed so that the status of the data logging device (2) can be monitored and selected at any time by menu selection.

In this embodiment, the data logging device (2) can be remotely controlled by key operations on the host computer (6). Data can also be received by any computer that uses the TIAC PS Q816 or has an RS 232C or GP-IB interface.

The data (14 bytes for one axis in this embodiment) recorded in the auxiliary storage device is processed in the following procedure.

As in the recorded data example (two lanes in one direction) shown in Figure 4,
Elapsed time from the start of measurement 7, Elapsed time from start trigger to stop trigger T (・ty t+)
, By converting the binary data into a switch signal, the passing speed v1 of each axis becomes "[,/T*0゜036 (km/h)]
It is found in J. Depending on the position of the ON switch signal, the vehicle is classified into three types: driving lane, crossing lane (driving across lane marks), and overtaking lane. The left and right edges of the left wheel from the switch signals classified into each lane,
The positions of the left and right ends of the right wheel are determined, and the width of the wheel, the center position of the wheel, the outer width of the wheel (vehicle width), the center position of the vehicle, etc. are calculated.

Vehicles are classified into two-wheeled vehicles, single tires, and double tires based on the width of their wheels, and are also divided into the following five types based on their outer width (vehicle width).

100cm or less Motorcycles 100-140cm @ Light vehicles 140-160cm Ordinary cars/small trucks 1Hcm or more Large trucks/trailer or No. 5
As shown in the figure, the axle distance from the previous axle is calculated from the difference between the passing time of the previous axle and the passing time of the focused axle and the traveling speed, and its size, the deviation of the vehicle center position, and the vehicle width It is determined whether the axle of interest is a front-most axle or a subordinate axle based on the result of vehicle type determination. Currently, the axis distance is 10
This value is used because there are no vehicles exceeding m. Also, there are no vehicles with double tires on the front axle, so double tires are always subordinate. This kind of judgment is made for each axis of each lane, and then the number of axles for one vehicle is counted.
It calculates the passing time of the frontmost axle, the average traveling speed of each axle, and the distance from the last axle of the preceding vehicle. Finally, the vehicle type is confirmed by comprehensively determining the vehicle width, vehicle length (distance between the front axle and rear axle), number of axles, etc.

At present, the following frequency distribution is displayed on the screen through graphic processing of traffic flow, and a hard copy is available.

■Traffic volume by vehicle type ■Traveling speed ■Vehicle time interval (rTi axis passing time difference) ■Distance between vehicles (distance between the rear axle of the preceding vehicle and the front axle of the following vehicle) ■Vehicle center passing position ■Wheel center passing position Each distribution above Regarding ■ to ■, in addition to the distribution for all vehicles, it is also possible to calculate the distribution for each lane, the distribution for each vehicle type, and the distribution of combinations thereof (for example, the distribution of the traveling speed of large vehicles traveling in the overtaking lane). I can do it. All of these selections can be made using soft keys on the display. In addition to the frequency distribution, it is also possible to monitor the planar arrangement within a designated section every time, allowing you to view the running condition of each vehicle in an animation style.

By providing the load detection section (14) shown in FIG. 1, load measurement can be automated and an automatic heavy load column automatic observation system can be completed.

For automatic observation of traffic in two lanes in different directions, as shown in Figure 6, switch No. -7
Distinguish between the switching of 2 and the switching of 72→l,
The direction of travel (A, B) can be known.

<Effects of the invention> ■Traffic volume by vehicle type ■Traveling speed ■Vehicle headway time interval (front axle passing time difference) ■Vehicle u■Distance fi (distance between the rear axle of the preceding vehicle and the front axle of the following vehicle) ■Vehicle center passing position ■Wheel center passing position ■Information such as weight can be obtained without requiring human intervention. Also, highly accurate and reliable data can be easily detected (without requiring AD conversion). Therefore, it is highly effective in reducing costs. Furthermore, by interfacing with a computer, it is possible to monitor passing vehicles in real time.

Furthermore, since vehicle type determination is possible, if it is linked with an axle load meter, weight measurement can be performed unattended. Furthermore, since it is possible to check whether cars are entering or exiting the bridge, stress and vibration measurements of bridge members due to actual traffic can be performed unattended.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts showing an embodiment of the present invention,
FIG. 2 is an explanatory diagram of main parts showing one embodiment of the code switch (10) to be used. FIG. 3 is an explanatory diagram showing one embodiment of the entire system. FIG. 4 is an explanatory diagram showing an example of data. FIG. 5 is an explanatory diagram of the principle of measurement value processing. FIG. 6 is a plan view of main parts showing another embodiment of the present invention. FIG. 7 is an explanatory diagram of one of the conventional measurement methods. FIG. 8 is an explanatory diagram of one of the other conventional measurement methods. FIG. 9 is a front view of one of the instruments used in the measurements of FIG. 8. FIG. 1O is an explanatory diagram of yet another conventional measuring method. Figure 11 shows
It is an explanatory diagram of one of the conventional and other measurement methods,
FIG. 12 is a front view thereof, and FIG. 13 is a perspective view thereof. FIG. 14 is a flow diagram of data processing in the conventional example. FIG. 15 is an explanatory diagram that does not show yet another conventional method. (1)...Mud switch, (10)...Code switch, (11)...Pressure conductive rubber, (12)...
Plain knitted wire, (13)... silicone rubber, (14)...
Load detection section Figure 1 Figure 2 Figure 8 Figure 2 Halloy Figure 11 Figure 12 Figure 13 Procedure amendment (automatic) November 28, 1985 2, Name of invention Traffic flow automatic observation device 3 Persons involved Relationship to the incident 8,191 people Address (
Address) 4-3-27 Nakazaki Nishi, Kita-ku, Osaka-shi, Osaka Name (
Name) Fuji Engineering Geta Co., Ltd.
Naka Zorou Representative Director 1) Medium
2 Part 4, Agent address: 1-7-3 Kitahorie, Nishi-ku, Osaka, Showa
Month/Day (1) "Processed..." on page 4, line 12 of the statement.
was corrected to ``I processed it, but'' and further added 1 on line 13 of the cylinder on the same page.
Correct "although I did it" with "even though I did it." (2) "Axle load meter (X)" on page 5, line 13 of the specification is corrected to "axle load meter (n)." (3) On page 7, line 8 of the specification, after “...Measuring method”, “, Structural Engineering Journal, Vol. 32A 1.986
Insert "March 2016". (4) From line 19 on page 9 of the specification to line 20 on the same page, “(In this example, Kanazawa Control Instruments D L
I'll list -2000. )” is deleted.

Claims (1)

[Claims] At least two load sensors are arranged on the road surface so as to intersect with the traffic direction at a predetermined interval, and at least one of the load sensors is divided into blocks in the longitudinal direction,
An automatic traffic flow observation device characterized by being composed of individual unit sensors in charge of each block.