JPH0997394A - Traffic information collection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collect wide-rage data and perform responding operation to various commands from a central processor rather than sensing vehicle by composing a traffic information collection system of central processor installed at a center and a vehicle denser which is installed in a road, corrects vehicle sensing data and sends them to the center processor. SOLUTION: The vehicle sensor 14 installed on the road sends the collected vehicle sense data to the central processor 12 at the center, and the central processor 12 sends various command data and installation data on operation condition or a test command, etc., to the vehicle sensor 14. Here, a control unit 18 sends data for operation control and state monitoring of a vehicle sensing means, i.e., sensor data to the central processor 12 through a transmission device 15. When sensor control data such as various command data are sent from the central processor 12 to the vehicle sensor 14, on the other hand,the control unit 18 receives the sensor control data through the transmission device 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic information collecting system, and more particularly to recognizing an operating state of a vehicle detecting means installed in a vehicle monitoring area of a road at the end according to an instruction from a center, and detecting the vehicle detecting means from a remote location. It relates to a traffic information collection system that can be controlled from.

[0002]

2. Description of the Related Art In recent years, vehicle detectors have been installed on highways, highways, and the like to pass over roads in order to measure traffic congestion by measuring traffic volume and create road traffic information. A traffic information collection system is used that detects vehicles and sends the detected data to the central processing unit of the center. FIG. 9 shows a conventional example of such a traffic information collecting system. This traffic information collecting system is installed in a center 1, a central processing unit 2, a receiving unit 3 for receiving data sent to the central processing unit 2, and a vehicle monitoring area installed on a road to collect vehicle detection data. A vehicle detector 4 that collects and sends the vehicle detection data to the central processing unit 2, a receiving device 3 of the center 1, and a vehicle detector 4.
And a transmission device 5 provided between and.

The vehicle detector 4 includes a plurality of vehicle detection units 6
In addition, each vehicle detection unit 6 has an ultrasonic head 7 which is a sensor for vehicle detection. Then, the vehicle detection unit collects the vehicle detection data from the ultrasonic head and sends the collected vehicle detection data to the transmission device. The transmission device 5 includes a transmission processing unit 8
And an interface unit 9, and the interface unit 9
In step 1, the vehicle detection data received from the vehicle detection unit 6 is sent to the center 1 by the transmission processing unit 8 while matching the communication operation with each vehicle detection unit 6.

In the center 1, the vehicle detection data sent through the transmission device 5 is received by the reception device 3 and transferred to the central processing unit 2, and the central processing unit 2 processes and analyzes the received vehicle detection data. The vehicle detection data consists of data necessary for measuring the traffic volume, such as the traffic volume of vehicles traveling on the road. In addition to the above-mentioned vehicle detection data, the vehicle detection unit 6 also sends to the center 1 data indicating that the vehicle detection unit 6 or the ultrasonic head 7 has failed. In this conventional traffic information collecting system, the transmission operation is always performed from the vehicle detector 4 side to the center 1 (that is, the central processing unit 2) side.

[0005]

However, in the above-mentioned conventional traffic information collecting system, in its operation,
Transmission operation is always performed from the vehicle detector 4 side to the center 1 side, and various data and signals are sent to the central processing unit 2 as upstream information.
When a failure occurs in the vehicle detection unit 6 or the ultrasonic head 7, the central processing unit 2 recognizes the fact that the failure has occurred by the data sent from the vehicle detector 4, but the failure factor has been sent. There is a problem that it cannot be understood from the data, and the operator cannot know without going to the site.

Further, the central processing unit 2 on the side of the center 1 does not have a function of diagnosing the vehicle detector 4 located at a remote place (vehicle monitoring site) or setting operating conditions, and the central processing unit 2 can grasp at all. You cannot do it. Under such a condition, when performing system verification, a defect in data may be found even though it is not a malfunction. In such a case, it is desired to know what the local installation environment (system constant data) is, but there is a problem that the operator cannot know unless he or she goes to the site. Further, as a means for solving such a problem, there is a problem that the vehicle detector 4 cannot be reset.

The present invention has been made in view of the above problems, and its purpose is not only to collect vehicle detection data but also to collect a wider range of data and various commands from the central processing unit and the vehicle detector. It is to provide a traffic information collection system that can respond to the traffic information.

[0008]

In order to achieve the above object, the present invention provides a traffic information collecting system, a central processing unit installed in a center, and a vehicle detection data installed in a vehicle monitoring area on a road. A vehicle detector that collects and sends the vehicle detection data to a central processing unit, and the vehicle detector includes a plurality of vehicle detection means that collects vehicle detection data from a plurality of vehicle detection heads, and And a control means for controlling the operation of the vehicle detection means for transmitting vehicle detection data from the vehicle detector to the central processing unit, while controlling the operation of the vehicle detection means between the control means and the central processing unit. The main point is that data is sent and received for status monitoring.

Therefore, according to the present invention, the vehicle detection data necessary for the traffic volume measurement is sent by the vehicle detection means of the vehicle detector, while the control means transmits the data regarding the operation setting contents and the operation state of the vehicle detection means. Is sent to the central processing unit. In addition, from the central processing unit, various command data and operating condition setting data for the vehicle detector,
Alternatively, a test command or the like is sent. As a result, depending on the vehicle detector, not only the vehicle detection data but also a wider range of data can be collected, while the central processing unit issues various commands to check the local installation environment and set the operation of the vehicle detector. You can

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a central processing unit installed in a center, and installed in a vehicle monitoring area on a road to collect vehicle detection data. A vehicle detector for sending to a central processing unit, the vehicle detector controlling a plurality of vehicle detecting means for collecting vehicle detecting data from the vehicle detecting head, and controlling the operation of each vehicle detecting means. And a control unit for transmitting vehicle detection data from the vehicle detector to the central processing unit, and transmitting and receiving data for controlling the operation of the vehicle detection unit and monitoring the condition between the control unit and the central processing unit. Has the effect of performing.

According to a second aspect of the present invention, a transmission device is connected between the central processing unit and the vehicle detector to control a data transmission / reception operation between the two functional units. It has an effect that the sensing data and other data can be transmitted.

According to a third aspect of the present invention, the transmission device sends a clock signal to the vehicle detector, the vehicle detection and vehicle detection data transmission operation in the vehicle detector, and the sampling operation in the transmission device. Is configured to be synchronized with each other, and has an effect that an error becomes zero in a sampling operation between the vehicle detector and the transmission device.

According to a fourth aspect of the present invention, the vehicle detection means is configured to send vehicle detection data for identifying a normal vehicle and a large vehicle, and has an effect of not only passing a vehicle but also determining a vehicle type. Have.

According to a fifth aspect of the present invention, the control means collects data for checking the state of the vehicle detection means according to an instruction from the central processing unit and sends it to the central processing unit. Has the effect of monitoring the vehicle detector at.

According to a sixth aspect of the present invention, the data for checking the state of the vehicle detection means is constituted by vehicle detector operation status data or system constant data, and the operation state of the vehicle detector is The center has the function of grasping.

According to a seventh aspect of the present invention, the data for checking the state of the vehicle detector is pseudo data assuming a specific operation of the vehicle detector.
It has the function of diagnosing and inspecting vehicle detectors at the center.

According to an eighth aspect of the present invention, the control means receives the operation setting data of the vehicle detection means from the central processing unit, and sets and changes the operation conditions of the vehicle detection means. It has the effect of centrally managing the vessels.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a traffic information collecting system according to an embodiment of the present invention. This traffic information collection system is center 1
1, a central processing unit 12, a transmission / reception unit 13 for transmitting data from the central processing unit 12 or receiving data sent to the central processing unit 12, and a vehicle detection unit installed in a vehicle monitoring area on a road. It comprises a vehicle detector 14 for collecting data, and a transmission device 15 provided between the transmission / reception device 13 of the center 11 and the vehicle detector 14.

The vehicle detector 14 includes a plurality of vehicle detection units 16 as vehicle detection means, and each vehicle detection unit 16 has an ultrasonic head 17 which is an ultrasonic type vehicle detection sensor. ing. In addition to the ultrasonic head 17, various types of sensors such as an optical head and an electromagnetic head can be used as the sensor. In addition, the vehicle detector 1
4 has a control unit 18 as a control means which is connected to each vehicle detection unit 16 and controls the operation of these vehicle detection units 16. A microcomputer or the like is used as the control unit 18. An address bus 23 for polling and a data bus 24 for data transfer are connected between the control unit 18 and the vehicle detection unit 16, and the control unit 18 receives the operation status information and system constants from the vehicle detection unit 16. You can receive it. Further, a control signal line 25 is connected between the control unit 18 and the vehicle detection unit 16 so that various control signals can be sent from the control unit 18 to the vehicle detection unit 16.

The vehicle detector 14 transmits / receives data to / from the central processing unit 12 and sends the collected vehicle detection data to the central processing unit 12.
From the central processing unit 12, various command data, operating condition setting data, test commands, etc. are sent to the vehicle detector 14. Vehicle detector 14 in this embodiment
More specifically, the transmission and reception operations viewed from the side will be described. In the transmission operation, the vehicle detection unit 16 collects the detection signals from the ultrasonic head 17 and converts the collected signals into data to detect the vehicle. Data is created and sent to the central processing unit 12 via the transmission device 15. Also,
The control unit 18 communicates with the central processing unit 12 and sends data for operation control and condition monitoring of vehicle detection means, that is, sensor operating data to the central processing unit 12 via the transmission unit 15. To do. The vehicle detection data and the sensor operation data are transmitted from the vehicle detector 14 which is a device at the vehicle monitoring site on the terminal side to the center 1.
Since it is sent to one central processing unit 12, it has meaning as upstream information.

On the other hand, in the receiving operation of the vehicle detector 14, various command data, operating condition setting data, or sensor control data such as test command data is sent from the central processing unit 12 to the vehicle detector 14. Then, the control unit 18 receives the sensor control data via the transmission device 15.

The transmission device 15 has a transmission / reception processing section 19 and an interface section 20. The interface unit 20 is connected to the vehicle detection unit 16,
While matching the communication operation with each vehicle detection unit 16, the vehicle detection data received from the vehicle detection unit 16 is transferred to the transmission / reception processing unit 19 and further sent to the center 11. The transmission / reception processing unit 19 and the control unit 18 are directly connected by a data bus 21 and a control signal line 22. This transmission device 15 has a basic function of sampling the vehicle detection pulse signal sent from the vehicle detection unit 16, and
It also has a function of issuing a specific command to the control unit 18. Specific commands include, for example, requesting sensor operational status and system constant data during operational mode. The transmission device 15 also has a function of sending a control signal (clock signal) to the control unit 18 through the control signal line 22 to synchronize the clocks of the transmission device 15 and the vehicle detection unit 16. The transmission device 15 and the transmission / reception device 13 of the center 11, or the transmission device 15 and the vehicle detector 14 may be connected by a wired or wireless communication medium.

In addition, as seen from the entire traffic information collecting system of this embodiment, a plurality of transceivers 13 are connected to the central processing unit 12 of the center 11, and corresponding transceivers are connected to each transceiver 13. The vehicle detection data can be collected from all directions. The vehicle detector 14 used in this embodiment is
Is equipped with one control unit 18 and 16 vehicle detection units 16, and one ultrasonic head 17 is provided for each vehicle detection unit 16.

The operation of the traffic information collecting system having the above configuration will be described. FIG. 2 shows the principle of vehicle detection by the vehicle detector 14. Vehicle detection methods are broadly divided into a side emission type in which an ultrasonic head 17 is installed laterally on the side of the road in the direction of the road surface to detect a passing vehicle, and a position higher than the road surface above the driving lane of the road. There is an overhead type in which the ultrasonic head 17 is installed downward toward the road surface to detect a passing vehicle, but the measurement operation contents and the signals used in the operation are almost the same. The example shown in FIG. 2 corresponds to the side-sensitive vehicle detection method. In this vehicle detection method, the road shoulder width (assuming A meters) and the road width (assuming B meters) on the side of the road 31 where the ultrasonic head 17 is installed are measured in advance. Then, based on the measurement result, the time period in which the vehicle reflected wave 34 (sensing pulse signal) returned after the transmission wave 32 (pulse signal) emitted from the ultrasonic head 17 hits the vehicle 33 is received is determined. The vehicle gate signal 35 is set when the vehicle reflected wave 34 is received by calculation. This vehicle gate signal 35
The tip of the road shoulder of the road 31, that is, the portion corresponding to the position closest to the ultrasonic head 17 for the vehicle 33 is located near the gate 3
5a, and a portion corresponding to a position far from the ultrasonic head 17 to the vehicle 33 is a far gate 35b, and the vehicle reflected wave 34 is sensed between the near gate 35a and the far gate 35b.

The large vehicle information when a large vehicle is sensed is as follows. That is, as shown in FIG. 3A, the vehicle detection unit 16 senses each time the vehicle passes, and a sensing pulse is generated based on the sensing pulse.
The pulse length is different between a standard car and a large car. The large vehicle pulse is detected by the vehicle detection unit 16 and the vehicle is detected.
It is judged by the shortest pulse reflection time when the sensing pulse is created. At this time, when it is determined that the vehicle is a large vehicle, as shown in FIG. 3B, the sensing pulse when the large vehicle is sensed falls and then the large vehicle pulse rises, and then the next sensing pulse ( This can be a regular car or a large car) and keep it on until it gets up.

When the vehicle detector 14 is in operation, the ultrasonic head 17 emits a vehicle detection signal based on ultrasonic waves, that is, the transmitted wave 32, at a constant time interval, and the vehicle reflected wave 34 is also the ultrasonic wave. It is received by 17 within the time set by the vehicle gate signal 35. Transmit wave 3
Reference numeral 2 is a pulse signal continuously generated by the ultrasonic head 17. The vehicle detection unit 16 sends a vehicle detection signal (sensing pulse) obtained by receiving the reflected wave 34 by the ultrasonic head 17 to the transmission device 15, and the transmission device 15 converts the signal into data and sends it to the central processing unit 12. To send. The vehicle detection unit 16 also transmits a failure detection signal to the central processing unit 12 via the transmission device 15 when there is a failure in the vehicle detection unit 16 itself or the ultrasonic head 17, or a disconnection of a connection line with the ultrasonic head 17. Send to.

Further, the control unit 18 includes the vehicle detector 1
The operation status information of No. 4 and more specifically, the operation status information of each vehicle detection unit 16 is sent to the central processing unit 12 as the sensor operation status information. The sensor operation status information includes a detailed content at the time of failure detection or a signal indicating the operation mode of each vehicle detection unit 16. Details of the detected failure include head disconnection, vehicle detection unit abnormality, and reverberation wave abnormality. The operation mode signal includes normality of the sensor, transmission of pseudo data, and the like.
Further, the control unit 18 sends various signals or data to the transmission device 15 or the vehicle detection unit 16 in response to an instruction or request from the central processing unit 12. As an operation request / response in accordance with an instruction from the central processing unit 12, a predetermined vehicle detection unit 16 is requested to start from an initial operation in response to a sensor reset request from the central processing unit 12. When the vehicle detection unit 16 executes this request, the response is returned to the central processing unit 12. In addition, as an operation request / response according to an instruction from the central processing unit 12, in response to a pseudo data request from the central processing unit 12, a predetermined vehicle detection unit 16 is switched from the operation mode to the test mode. Request an action. Then, when the vehicle detection unit 16 executes this request, the response is sent to the central processing unit 1.
Return to 2.

The control unit 18 also receives data from the central processing unit 12. This data reception includes reception of system constant data. The system constant data is the setting information of the sensor, that is, the vehicle detection unit 16 or the ultrasonic head 17, which is set for each local installation environment for vehicle monitoring. The setting value of the near gate, the setting value of the gain, and the system number of the terminal. Etc. This system constant data is sent from the central processing unit 12 to the control unit 18, and the control unit 18 performs setting for each vehicle detection unit 16, or changes and updates of the setting, so that the center 11 manages set values. Do it intensively.
A unit number is added prior to the transmission of the sensor operation status information (from the control unit 18) and the transmission of the system constant data (from the central processing unit 12).

A signal sequence diagram for explaining the communication operation between the central processing unit 12 and the vehicle detector 14 is shown in FIGS. 4 and 5. Of these, FIG. 4 is a signal sequence diagram for explaining a communication operation in an operation mode in a normal operation and an operation of receiving control information from the central processing unit 12, and FIG. 5 is a pseudo data request from the central processing unit 12 in a test mode. FIG. 9 is a signal sequence diagram illustrating a communication operation in a response operation to the above and the response operation.

In the normal operation of FIG. 4, in the operation mode, the vehicle detection unit 16 transmits the signal obtained during the operation of receiving the reflected wave 34 by the ultrasonic head 17 to the transmission device 1.
5 (sequence (a) in FIG. 4). This signal includes a normal vehicle detection signal, a large signal for judging a large vehicle, and a failure signal when a failure occurs. In the transmission processing device 15, the vehicle detection unit 16
The signal sent from is converted into data, and this data is
Framed together with other data, the central processing unit 12
(Sequence (b) in FIG. 4). The frame structure of this data will be described later. Center 1
In 1, the vehicle detection data sent through the transmission device 15 is received by the transmission / reception device 13 and transferred to the central processing unit 12, and the central processing unit 12 processes and analyzes the received vehicle detection data. The vehicle detection data consists of data necessary for measuring the traffic volume, such as the traffic volume of vehicles traveling on the road.

In the sensor operation status and system constant data request / response mode, the request information for the above data is sent from the transmission device 15 to the control unit 18 at a constant cycle (sequence (c) in FIG. 4). In response to this, the control unit 18 reads the sensor operation status information and system constant data from the memory in the control unit 18 and sends them to the transmission device 15 ((d) in FIG. 4).
Sequence), the transmission device 15 sends the data to the central processing unit 12 (sequence (e) in FIG. 4). On the other hand, the control unit 18 controls each vehicle detection unit 16
Requesting each operation status and constant data (sequence (f) in FIG. 4), receiving the transmission (sequence (g) in FIG. 4) and storing it in the memory in the control unit 18.

Further, in the sensor reset mode, the control unit 1 is transmitted from the central processing unit 12 via the transmission device 15.
A reset control signal is sent to 8 (sequence (h) in FIG. 4). This reset control signal includes a unit number for resetting a specific vehicle detection unit 16. Then, the reset control signal is analyzed by the control unit 18 in the vehicle detector 14 and sent to the designated vehicle detection unit 16 to reset the vehicle detection unit. Due to this reset, the vehicle detection unit 16 becomes the initial operation.
When the reset is completed, a response indicating that the reset has been executed is returned from the control unit 18 to the central processing unit 12 via the transmission device 15 (sequence (i) in FIG. 4).

Next, the operation shown in FIG. 5 will be described. This operation is a pseudo data request from the central processing unit 12 and a response operation thereto. This action causes a pseudo signal to be sent to check whether a particular vehicle sensing unit 16 is working properly. In this operation, a pseudo data request signal is sent from the central processing unit 12 to the control unit 18 via the transmission device 15 (sequence (j) in FIG. 4).
The pseudo data request signal is analyzed by the control unit 18 in the vehicle detector 14 and requests the designated vehicle sensing unit 16 to switch the vehicle sensing unit from the operational mode to the test mode. Then, when the mode switching is completed, a response indicating that the mode switching has been performed is returned from the control unit 18 to the central processing unit 12 via the transmission device 15 (sequence (k) in FIG. 4). On the other hand, a pseudo signal is sent from the designated vehicle detection unit 16 to the transmission device 15 (sequence (m) in FIG. 4). The pseudo signal includes a pseudo vehicle detection signal, a pseudo large signal, and a pseudo fault signal. In the transmission processing device 15, the pseudo signal sent from the vehicle detection unit 16 is converted into data, this data is framed and sent to the central processing unit 12 (sequence (n) in FIG. 4).

In the transmission processing device 15, the upstream information is framed and sent to the central processing device 12. The frame structure of this data will be described below.
6 and 7 show an example of a frame structure of data (for one frame) and a character structure of upstream information forming the frame in the present embodiment. As shown in FIG. 6, the frame has 12 transmission blocks (B1 to B1) each having a transmission cycle of 20 msec (millisecond: 1/1000 second).
B12) Composed together. Each block is divided into four sections (S1 to S4), and each section stores one of the characters A to H and I1 to I7. One section can store 8-bit data. In the example of FIG. 6, the first block B
The first section S1 of 1 has an A character, the second section S2 of the first block B1 has a B character, the third section S3 of the first block B1 has a C character, and the fourth section S4 of the first block B1 has It is stored as E character, ....

Explaining the character structure with reference to FIG. 7, the A character is composed of 8-bit data D01 to D08. In this character, the least significant bit LSB (Least Significant Bit) is assigned as the start bit ST, and the most significant bit M
The 2 bits on the SB (most sig- nificant bit) side are assigned as stop bits SP and at the same time
The lower bit is assigned as a parity bit PT. The method of allocating the least significant bit and the most significant 3 bits is the same for other characters. B
The following table shows the structure of the characters.

[Table 1] Here, the contents of each data are as follows. D01 ~ D
Reference numeral 16 is a sensor raw pulse signal. This corresponds to vehicle sensing data. Further, the numbers 01 to 16 indicate the numbers corresponding to each of the 16 vehicle detection units 16 (equivalent to the ultrasonic head 17), and D01 is the sensor raw pulse signal of the 1st vehicle detection unit, D02 is 2
No. 3 vehicle detection unit sensor raw pulse signal, D03 means No. 3 vehicle detection unit sensor raw pulse signal. As described above, the vehicle detector 14 of this embodiment includes 16 vehicle detection units 16 and one ultrasonic head 17 is provided for each vehicle detection unit 16. L01 to L16 are large vehicle information, F01 to F16 are sensor failure numbers, DN1 to DN
5 is a sensor number (binary 1 to 16), DS1 to D
S3 is a sensor operation status, IS1 to IS4 are response information, GN1 to GN4 are pseudo data numbers, DA1 to DA1.
DA8 is system constant data.

From the above, when the frame structure of FIG. 6 is examined again, the A character is stored in the first section S1 of the first block B1 of the frame of FIG. This is because the data content is the sensor raw pulse signal,
From 1 to 08, the sensor raw pulse signals from the first vehicle detection unit 16 to the eighth vehicle detection unit 16 are stored. The second section S of the first block B1
B character is stored in 2. This is similar to the A character of the first section S1 described above, the data content is the sensor raw pulse signal, and from 09 to 016,
The sensor raw pulse signals from the ninth vehicle sensing unit 16 to the 16th vehicle sensing unit 16 are stored. Therefore, with character A and character B, 1
All the sensor raw pulse signals (ie, vehicle detection data) of the six vehicle detection units 16 will be stored.

Next, the C character is stored in the third section S3 of the first block B1. This is because the data content is large vehicle information, and from 01 to 08, 1
Information on large vehicles from the 8th vehicle detection unit 16 to the 8th vehicle detection unit 16 is stored.

Next, an E character is stored in the fourth section S4 of the first block B1. This is because the data content is a sensor failure signal, and the sensor failure signals from 01 to 08 to the first vehicle detection unit 16 to the eighth vehicle detection unit 16 are stored.

Next, the D character is stored in the third section S3 of the second block B2. Similar to the C character of the third section S3 of the first block B1, the data content is large vehicle information, and 09-
The large vehicle information from 016 to the 9th vehicle detection unit 16 to the 16th vehicle detection unit 16 is stored. Therefore, the character C and the character D have stored all the large vehicle information of the 16 vehicle detection units 16. However, the C character is in the first block B1 and the D character is in the second block B2.
By storing the blocks separately, all the large vehicle information of the 16 vehicle detection units 16 cannot be received unless the two blocks are received.

Next, the F character is stored in the fourth section S4 of the second block B2. This is similar to the E character in the fourth section S4 of the first block B1, the data content is a sensor failure signal, and 0
9 to 016, 9th vehicle detection unit 16 to 1
The sensor failure signals up to the sixth vehicle detection unit 16 are stored. Therefore, the character E and the character F store all the sensor failure signals of the 16 vehicle detection units 16. However, since the E character is stored in the first block B1 and the F character is stored in the second block B2, the 16 vehicle detection units 16 cannot be received unless two blocks are received.
It is unable to receive all the sensor failure signals of.

In the same manner, the storage state of each character can be known. It should be noted that the characters I1 to I7 are different from data unique to the vehicle detection unit 16 (system), unlike the character A or the like representing the sensor raw pulse signal is common data for the entire 16 vehicle detection units 16. Constant data), and for this character,
The data is stored from the block B5 to the block B11 and becomes a data having one meaning only when all of these data are received.

A data mixed type frame having the above configuration is generated for each vehicle detection unit 16 and is sent to the central processing unit 12 sequentially from the first vehicle detection unit 16 in the data transmission operation of the upstream information. To be done.
The transmission procedure of this frame data is shown in FIG.
That is, first a frame of No. 1 sensor (corresponding to the vehicle sensing unit 16) data is transmitted. The time required for transmission is 20 × 12 = 240 (msec).

Next, the second sensor data frame is transmitted. The time required for transmission is the same as above. After the transmission of the third sensor data, the fourth sensor data, the fifth sensor data, ..., And the 16th sensor data, the frame of the first sensor data is transmitted again. Like Therefore, the time required from the transmission of the first sensor data to the end of the transmission of the 16th sensor data is 240 × 16 = 3840 (msec) =
It is 3.84 (sec).

The operation of collecting the vehicle detection data is executed in such a cycle. Looking again at the frame shown in FIG. 6, since the A character and the B character are assigned to all the blocks B1 to B12, the detection is performed. It can be seen that the organic pulse signal is detected every 20 msec. On the other hand, since the C character and the D character are assigned to every other block, the large vehicle information is 40.
It can be seen that it is detected every msec. With respect to the other information as well, the detection cycle is obtained by considering in the same manner, and various kinds of information can be transmitted at different detection cycles depending on the importance of each information.

Next, the sampling operation of the vehicle sensing pulse signal in the transmission device 15 used in the present invention will be described. The vehicle detection data of the ultrasonic type vehicle detector 14 is
As described above, ultrasonic signals are emitted at regular intervals, and the presence of a vehicle is detected by the presence or absence of the reflected waves. Here, a certain fixed time interval (sampling period)
Let us consider the case where the presence of a vehicle and the signal are detected, that is, sampling is performed. The vehicle detection pulse signal based on ultrasonic waves is output from the vehicle detection unit 16 to the transmission device 15 at a multiple of the sampling cycle of ultrasonic waves. On the other hand, the vehicle detection pulse signal is sampled by the transmission device 15 and transmitted to the central processing unit 12.

The problem here is that in a general transmission device (conventional transmission device), a sampling error occurs when the sampling period of the transmission device and the sampling period of ultrasonic waves are simply matched. That is, for example, in the case of targeting vehicle measurement on a highway, the vehicle speed to be measured is high, and therefore the error of one sampling pulse has a great influence on the measurement information.

As an example, when the vehicle length is 5 meters (m) and the vehicle travels at 100 kilometers per hour (km), the sampling cycle of the vehicle detection unit 16 is 60 (mse).
c), when the sensing area is calculated as 0.5 (m), vehicle passage time = (vehicle length + sensing area) (m) / vehicle speed (m / s) = (5 + 0.5) / (100/3. 6) = 198 (msec) Therefore, theoretical number of samplings = vehicle passing time / sampling period (msec) = 198 (msec) / 60 (msec) = 3.3.

The theoretical sampling number 3.3 is "3" in reality, and the pulse length of the vehicle sensing pulse signal is 180 (msec). Next, when this transmission pulse signal is sampled by a general transmission device, a sampling error occurs on the transmission device side. This error will be explained. In the transmission device, when the vehicle detection pulse signal is assumed to be sampled at 20 (msec), the transmission side clock error and the ultrasonic wave side clock error with respect to the above 180 (msec). It becomes as follows by correlation with. Transmission clock> ultrasonic clock,
The number of samplings may be eight. Transmission clock <
In the case of the ultrasonic clock, the sampling number may be 10. In the case of the transmission clock = the ultrasonic clock, the sampling number is 9.

The sampling error thus generally has ± 1. In this example, ± 20 (mse
As a result of the sampling error of c), the maximum error is ± 11% with respect to 180 (msec) of the ultrasonic sensor. To prevent this maximum error, the clock error can be made zero by synchronizing the clocks of the transmission device and the ultrasonic sensor.

The transmission device 15 in the present invention sends a clock signal from the transmission device 15 side to the control unit 18 through the control signal line 22, so that clock synchronization is performed between the transmission device 15 and the ultrasonic vehicle detection unit 16. Therefore, the sampling error can be made zero.
Therefore, in the present invention, the ultrasonic type vehicle detection unit 1 is used.
It is possible to transmit the vehicle measurement sensing data obtained by No. 6 to the central processing unit 12 without error, thereby achieving improvement in measurement accuracy of a high-speed vehicle in particular.

[0052]

As described above, according to the present invention,
As a traffic information collection system, a central processing unit installed in the center and a vehicle detector installed in a vehicle monitoring area on the road to collect vehicle detection data and send this vehicle detection data to the central processing unit. The vehicle detector has a plurality of vehicle sensing means for collecting vehicle sensing data from a plurality of vehicle sensing heads, and a control means for controlling the operation of each vehicle sensing means. While sending vehicle detection data to the processor,
Since data is transmitted and received between the control means and the central processing unit to control the operation of the vehicle detection means and monitor the condition, a wider range of data relating to vehicle detection is collected and various commands from the central processing unit. Can respond to.

Further, in the present invention, a clock signal is sent from the transmission device side to the vehicle detector side and clock synchronization is established between the transmission device and the vehicle detection unit, so that the sampling error can be made zero. The vehicle measurement sensing data obtained by the vehicle sensing unit can be transmitted to the central processing unit without error. As a result, the measurement accuracy of a high-speed vehicle is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a traffic information collecting system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing the principle of vehicle detection by a vehicle detector used in the traffic information collecting system of the present invention.

FIG. 3A is a signal waveform diagram showing a sensing pulse created by the vehicle sensing operation in the embodiment. FIG. 3B is a signal waveform of a large vehicle pulse showing large vehicle information obtained from the signal waveform of the sensing pulse. Figure

FIG. 4 is a signal sequence diagram illustrating a communication operation in an operation mode and an operation of receiving control information from a central processing unit according to the above embodiment.

FIG. 5 is a signal sequence diagram for explaining a communication operation in a pseudo data request from the central processing unit and a response operation to the pseudo data request in the test mode of the embodiment.

FIG. 6 is a frame configuration diagram showing an example of a frame configuration of data used in the embodiment.

FIG. 7 is a character configuration diagram showing an example of a character configuration of upstream information used in the embodiment.

8 is an explanatory view schematically showing a transmission order of the data having the frame structure shown in FIG. 6 over a plurality of vehicle detection units.

FIG. 9 is a block diagram showing the configuration of a conventional traffic information collection system.

[Explanation of symbols]

 11 center 12 central processing unit 13 total reception device 14 vehicle detector 15 transmission device 16 vehicle detection unit 17 ultrasonic head 18 control unit 19 transmission processing unit 20 interface unit 22, 25 control signal line 23 polling address 24 data transfer data bus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yosuke Kyo Tokuyo 4-3-1, Tsunashima-higashi, Kohoku-ku, Yokohama-shi, Kanagawa Matsushita Communication Industrial Co., Ltd. (72) Inventor, Masaru Iyama Kohoku-ku, Yokohama-shi, Kanagawa 4-3-1, Tsunashima East Matsushita Communication Industry Co., Ltd.

Claims (8)

[Claims] 1. A central processing unit installed in a center,
The vehicle detector is installed in a vehicle monitoring area on a road, collects vehicle detection data, and sends the vehicle detection data to a central processing unit. It has a plurality of vehicle sensing means for collecting data and a control means for controlling the operation of each vehicle sensing means. While sending vehicle sensing data from the vehicle detector to the central processing unit, the control means and the central processing A traffic information collection system, which transmits and receives data for controlling operation of a vehicle detection means and monitoring a condition with a device. 2. The traffic information collecting system according to claim 1, further comprising a transmission device connected between the central processing unit and the vehicle detector for controlling a data transmission / reception operation between the functional units. system. 3. The transmission device sends a clock signal to the vehicle detector to synchronize the vehicle detection and vehicle detection data transmission operation of the vehicle detector with the sampling operation of the transmission device. The traffic information collection system described in 2. 4. The traffic information collecting system according to claim 1, wherein the vehicle detection means sends vehicle detection data for identifying a normal vehicle and a large vehicle. 5. The control means collects data for checking the state of the vehicle detection means according to an instruction from the central processing unit and sends it to the central processing unit. Traffic information collection system described. 6. The traffic information collecting system according to claim 5, wherein the data for checking the state of the vehicle detection means is vehicle detector operation status data or system constant data. 7. The traffic information collecting system according to claim 5, wherein the data for checking the state of the vehicle detecting means is pseudo data assuming a specific operation of the vehicle detector. 8. The traffic according to claim 1, wherein the control means receives operation setting data of the vehicle detection means from the central processing unit and sets and changes the operation conditions of the vehicle detection means. Information collection system.