JP5298712B2 - Sensor abnormality detection system, method, sensor abnormality detection device, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine whether a vehicle sensor operates normally or not. <P>SOLUTION: The vehicle sensor 2 measures a traffic volume on each lane of road A and transmits the measured results to a traffic control center. Vehicles equipped with a unit enabling communication between vehicles on road, including vehicle C, create probe information of the road A and transmit it to a wireless communication device 7 on road and to the traffic control center. The detecting device 5C for detecting abnormal condition of sensor located at the traffic control center estimates the traffic volume on the road A based on the probe information at the same time and at the same location, compares it with the measured traffic volume information, and concludes an abnormal condition if the difference is a predetermined threshold or above. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sensor abnormality detection system that detects an operation abnormality of a vehicle sensor installed on a road using probe information collected from an in-vehicle device.

Conventionally, in order to collect traffic information, a method has been used in which vehicle detectors are installed on a road at predetermined intervals to measure the number of vehicles passing (traffic volume), occupied time, and the like.
Because traffic signal control and traffic information are provided using the traffic volume measured by the vehicle detector, the influence of the failure or failure of the vehicle detector on the traffic system is large.
Up to now, as a method for detecting a failure or the like of a vehicle detector, for example, when the vehicle detection signal of the vehicle detector is in a state of being continuously detected, it is determined to be abnormal (see Patent Document 1), or is detected for a predetermined time or more. A method of determining that there is no abnormality has been used.

  In recent years, for the purpose of acquiring traffic information on roads where vehicle detectors are not installed, the vehicle generates probe information related to its own travel locus and transmits it to the center side device at predetermined intervals. A method of acquiring a link travel time of a road by analyzing probe information transmitted from a plurality of vehicles on the center side has also been used (see Patent Document 1). At present, since the number of vehicles that can transmit probe information has reached a predetermined ratio, various utilization methods other than acquisition of travel time and the like are conceivable.

JP-A-3-29096 JP 2002-251698 A

As a method for detecting an abnormality of a vehicle detector, it is not sufficient to determine whether or not a failure is caused only by whether or not the vehicle detection signal has been continuously detected. It was desired to be able to detect abnormalities.
(1) The vehicle detection head of the vehicle detector (for example, an ultrasonic head for an ultrasonic sensor)
Sensing because the installation angle and other conditions have changed for some reason after installation.
Leakage occurs or a vehicle in a different lane is mistakenly detected.
(2) The branch is mistakenly mistaken for a vehicle due to the swinging branch of the roadside tree.
Yeah.
(3) In the case of image processing type vehicle detectors, etc.
Defects in image processing may occur due to factors such as effects and camera contamination, resulting in vehicle detection errors and errors.
Sensation occurs.
(4) Due to errors in maintenance work by workers, parameters etc. to be set in the vehicle detector
An error occurs, resulting in a vehicle being missed or misdetected.

However, it is not desirable to introduce new road equipment or increase the number of inspection operations for the purpose of detecting an abnormality in the vehicle detector because of increased costs.
Therefore, an object of the present invention is to provide a sensor abnormality detection system that can detect abnormality of a vehicle sensor as described in the above (1) to (4) without introducing new road equipment.

The sensor abnormality detection system according to the present invention includes a probe information collection unit that collects travel locus information transmitted from a plurality of vehicles traveling on a road, and the vehicle sensor installed on the road. Sensor information collecting means for collecting sensor information relating to the traffic flow of the road, and a traffic flow estimating means for estimating the traffic flow of the road based on the travel locus information collected by the probe information collecting means, A determination unit configured to determine whether or not the sensor information is valid by comparing the estimated traffic flow with the sensor information of the same time period collected on the date of the estimation; (Claim 1).

  According to the present invention, it is possible to determine whether or not the traffic flow measurement of the vehicle detector is normally performed using travel locus information collected from a plurality of vehicles. Without it, it becomes possible to monitor the operating state of the vehicle detector.

  Here, the traffic flow estimation means estimates the road from a probe car rate, which is a ratio of vehicles that can transmit travel locus information among vehicles traveling on the road, and the number of collected travel locus information. The traffic volume is calculated, and the determination means obtains the measured traffic volume actually measured by the vehicle sensor and included in the sensor information, and compares the measured traffic volume with the estimated traffic volume. When the difference from the amount is equal to or greater than a predetermined threshold value, it is preferable to determine that the measured traffic volume included in the sensor information is inappropriate (Claim 2).

  By using a method for determining the appropriateness of the measured traffic volume by comparing the estimated traffic volume and the measured traffic volume, the state of the vehicle detector can be objectively determined.

  In addition, since the average travel speed of the vehicle and the end position of the traffic jam can be estimated from the travel locus information, for example, the validity of the measurement result of the vehicle detector may be determined by comparing the estimated value with the measured value. (Claims 3 and 5). In addition, if the information on the vehicle type is included in the travel locus information, it is possible to estimate the large vehicle mixture rate. Therefore, the vehicle detector measurement is performed by comparing the estimated value of the large vehicle mixture rate with the measured value. The validity of the result may be determined (claim 4).

It is more preferable to calculate a traffic flow such as the estimated traffic volume for each of a plurality of lanes of the road and determine whether or not the measured traffic volume is appropriate for each lane of the road. This is because the operation state of the vehicle detector can be determined finely by performing the operation for each lane.
In addition, a sensor abnormality detection device provided with an abnormality determination method, determination means, and the like in this sensor abnormality detection system, and a computer program for executing the determination step are also very useful (claims 7 to 9).

  As described above, according to the sensor abnormality detection system of the present invention, the roadside instructs each vehicle-mounted device on the probe information creation method, and the vehicle-mounted device creates probe information according to the instruction and transmits it to the roadside. Therefore, it is possible to efficiently collect probe information having contents that are easy to handle on the roadside.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an outline of device arrangement of a sensor abnormality detection system according to the present invention.

[Overall system configuration]
The traffic signal controller 1 is installed at the intersection A, and the right of passage is displayed for the vehicle C and the like traveling on the road A toward the stop line P by controlling the signal lamp 1A. The traffic signal controller 1 has a wireless communication device 7 built in a casing, and can perform road-to-vehicle communication with an in-vehicle device mounted on a vehicle on the road A through an antenna 7A.
A vehicle detector 2 is installed upstream of the intersection A, and sensing heads 2A to 2C are provided for each lane. The lanes corresponding to the respective heads are referred to as lanes A to C, and the traveling directions of the lanes are all directions toward the stop line P.

The traffic signal controller 1 and the vehicle detector 2 are connected to a terminal router 3 installed on the roadside, and a central device such as a probe information collecting device 5A installed on the traffic control center side through a communication line or the central router 4 Connected with.
Among vehicles traveling on the road A, some vehicles including the vehicle C are equipped with an in-vehicle device that can communicate with the wireless communication device 7 (the in-vehicle device of the vehicle C is the in-vehicle device 6). Road-to-vehicle communication can be performed.

[Contents of probe information]
FIG. 2 is a diagram illustrating a concept in which the vehicle-mounted device 6 creates probe information indicating the traveling locus of the vehicle C and transmits the probe information to the antenna 7A. FIG. 3 is a diagram illustrating an example of the probe information.
As shown in FIG. 2, the vehicle-mounted device 6 records the latitude / longitude of the point and the passage time at four points 1 to 4 while traveling along the lane B toward the stop line P, and uses it as probe information. Store. At this time, the state of the headlight and the like at the time of passing the point can be recorded together with the latitude / longitude and the passing time.
The in-vehicle device 6 creates probe information including information on a plurality of points that have passed, and then transmits the probe information toward the antenna 7A.

Note that the probe information transmitted from the in-vehicle device 6 may have any data format, and may be subjected to data compression or the like in order to increase communication efficiency. Further, the location and number of points stored in the probe information may be determined in any way as long as the travel locus of the vehicle can be grasped.
The created probe information is received by the wireless communication device 7 and then sent to the probe information collecting device 5A through the terminal router 3 and the central router 4 and stored as a probe information database.

[Basic operation of vehicle detector]
The vehicle detector 2 periodically transmits ultrasonic waves from the heads 2A to 2C to the road surface of the road A, and has a function of receiving reflected waves from the road surface of the ultrasonic waves transmitted by itself. .
The time from sending the ultrasonic wave to receiving the reflected wave is usually equal to the time taken for the sound wave to propagate a distance twice the distance between the head and the road surface. Is present, the ultrasonic waves bounce off the ceiling of the vehicle, so that the reflected wave is received in a shorter time than usual.
That is, the vehicle determines whether or not there is a vehicle immediately below the head depending on whether or not the time from sending an ultrasonic wave to receiving the reflected wave is within a predetermined threshold. Is perceived.

The ultrasonic waves are intermittently sent toward the road surface, and the presence / absence of the vehicle can be measured every unit time (for example, every 50 ms).
The presence / absence of the vehicle for each unit time is observed in time series, and when the vehicle changes from the presence to the absence, it is determined that one vehicle has passed and the traffic volume is counted up by one.
Further, the occupation time of the vehicle on the road can be calculated based on the ratio of the presence time to the absence time, and an approximate average traveling speed can be estimated from the occupation time. The greater the occupied time, the lower the traveling speed, and the smaller the occupied time, the greater the traveling speed.

  When the vehicle C travels as shown in FIG. 2, the passage of the vehicle C is detected by the vehicle detector 2 installed on the route. Since the vehicle C traveled on the lane B and passed under the head 2B of the vehicle detector 2, the vehicle detector 2 increments the traffic volume on the lane B by one when the vehicle C passes. The approximate traveling speed can also be estimated based on the occupation time.

In addition, although the ultrasonic type vehicle sensor was described here as an example, any type of vehicle sensor that can calculate traffic volume, occupation time, etc., such as an optical type, an image processing type, a far infrared type, etc. A vehicle sensor may be used. In the case of an image-type vehicle detector or the like, it is also possible to directly measure the traveling speed of the vehicle and the traffic jam length.
The traffic volume and occupation time calculated in this way are transmitted to the traffic control center at a predetermined cycle in response to a request from the sensor information collection device 5B.

[Basic operation of sensor abnormality detection device 5C]
Hereinafter, the basic operation of the sensor abnormality detection device 5C will be described.

  The sensor abnormality detection device 5C receives the probe information group collected within a predetermined time from the probe information collection device 5A at regular intervals. Moreover, the sensor information group collected within the predetermined time is also received from the sensor information collecting device 5B. The individual information contained in these probe information groups and sensor information groups is given the collected points (roads) and time, and can identify when and where the information was obtained. The sensor abnormality detection device 5C extracts and analyzes probe information and sensor information on the same road in the same time zone from the received probe information group and sensor information group.

First, a plurality of pieces of probe information in a target time zone and road are sequentially extracted from the received probe information group. Here, the probe information of the road A at one day in the day (13:00 to 14:00) is extracted.
If the number of pieces of probe information extracted here is less than a predetermined number (for example, 30 or less), it is difficult to accurately estimate the traffic situation, so that the abnormality determination is impossible at that time. Exit.

Next, the travel lane of the vehicle that has transmitted the probe information is determined from the latitude and longitude of the passing points included in the extracted plurality of probe information. The travel lane is determined by storing in advance a region where the lanes A to C of the road A are present in a table, and in which region the latitude and longitude of the passing point are included. In this way, the lanes traveled for all the probe information are determined, and the number of passing vehicles for each lane is obtained.
Then, an estimated value of the total number of passing vehicles for each lane in this one hour is calculated from the mounting rate of the vehicle-mounted device that can create and transmit the probe information. For example, if the mounting rate of the in-vehicle device is 10%, the estimated value is calculated by multiplying the number of passing vehicles for each lane determined by the probe information by 10. Since the mounting rate can change dynamically, it is desirable to review it periodically and set it as an appropriate value.

  Next, the probe information of the road A from 13:00 to 14:00 on the target day is extracted from the received sensor information group. Normally, sensor information is recorded at intervals of about every 5 minutes, so each time from 13:00 to 13: 5, 13: 5 to 13:10, ..., 13:55 to 14:00 The sensor information is extracted. And the cumulative value of the traffic volume for each lane in these 12 time zones is calculated.

  And the estimated value of the traffic volume of each lane of the road A calculated | required from the probe information group and the accumulated value of the traffic volume calculated from the sensor information group are compared. If the difference between these values is within a predetermined threshold, the vehicle detector is normal, and if the difference is greater than or equal to a predetermined value, it is determined as abnormal. The threshold value in this case may be set to a value such as about 10% of general traffic volume.

In addition to the travel lane, since the travel speed can be calculated from the distance between the passing points of each probe information and the required time, the average travel speed for each time zone can be estimated by using the probe information. . It is possible to determine whether or not the measurement of the speed information is normal by comparing the average traveling speed with the speed information measured by the vehicle detector.
In addition, if information related to the vehicle type is also stored in the probe information, it is possible to estimate the mixing ratio of large vehicles and compare it with the sensor information. It is also possible to estimate the traffic jam end position from the probe information and compare it with the traffic jam length measured by the vehicle detector.

For example, when vehicle detector abnormality determination is performed at regular intervals such as every hour by the above method, a list in which vehicle detectors that are determined to be abnormal are arranged in order is displayed in the form of a form. It is possible to output automatically, and when performing maintenance work, the priority of work can be easily determined.
In addition, it is desirable that traffic information measured by a vehicle detector that is determined to be abnormal is excluded from the target of providing traffic information to the driver or not used when performing traffic signal control. In this case, if it is determined that the abnormality is concentrated at night, a method may be used in which the time zone when the sensor information is not used is only at night.

  Here, an example in which the sensor abnormality detecting device 5C is installed as a device different from the probe information collecting device 5A and the sensor information collecting device 5B is shown, but the probe information collecting device 5A and the sensor information collecting device 5B are provided. A function for determining a sensor abnormality can be implemented and used, or these three devices can be used as one device. In this way, it is possible to appropriately adopt a configuration suitable for an existing system.

In the above embodiment, the traffic volume for each lane is estimated from the probe information and compared with the measured traffic volume actually measured by the vehicle detector 2, but the accuracy of the latitude / longitude positions included in the probe information is If it is difficult to specify the lane that has traveled due to poor traffic, the estimated traffic volume for all lanes on road A is calculated, and the measured traffic volume for the three lanes of the sensing heads 2A to 2C A method of comparison can also be used. The same applies to the travel speed and the like as well as the traffic volume.

  Note that the probe information collection device 5A, the traffic signal controller 1 and the like according to the present invention may be realized by a single casing or a combination of a plurality of casings. Each of these may be realized by one computer or may be realized by combining a plurality of computers.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic diagram which shows the outline | summary of apparatus arrangement | positioning of the sensor abnormality detection system which concerns on this invention. It is a figure which shows the concept which the vehicle equipment 6 produces probe information and transmits the said probe information addressed to antenna 7A. It is a figure which shows an example of probe information.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traffic signal controller 1A Signal lamp 2 Vehicle detectors 2A-2C Sensing head 3 Terminal router 4 Central router 5A Probe information collection device 5B Sensor information collection device 5C Sensor abnormality detection device 6 In-vehicle device 7 Wireless communication device

Claims (9)

Probe information collecting means for collecting traveling locus information transmitted from a plurality of vehicles traveling on a road;
Detector information collecting means for collecting sensor information relating to traffic flow of the road measured by a vehicle detector installed on the road,
Traffic flow estimation means for estimating the traffic flow of the road based on the travel locus information collected by the probe information collection means;
A determination means for determining whether or not the sensor information is valid by comparing the estimated traffic flow with the sensor information of the same time zone collected on the date of the estimation ; A sensor abnormality detection system comprising: The traffic flow estimation means includes
Calculate the estimated traffic volume of the road from the probe car rate, which is the proportion of vehicles that can transmit the travel locus information among the vehicles traveling on the road, and the number of collected travel locus information,
The determination means includes
When the measured traffic actually measured by the vehicle sensor and included in the sensor information is acquired and compared with the estimated traffic, and the difference between the measured traffic and the estimated traffic is greater than or equal to a predetermined threshold The sensor abnormality detection system according to claim 1, wherein the measured traffic included in the sensor information is determined to be invalid. The traffic flow estimation means includes
Based on the travel trajectory information collected by the probe information collection means, calculate the estimated average travel speed of the vehicle on the road,
The determination means includes
A measured average traveling speed actually measured by the vehicle sensor and included in the sensor information is acquired and compared with the estimated average traveling speed, and a difference between the measured average traveling speed and the estimated average traveling speed is predetermined. 3. The sensor abnormality detection system according to claim 1, wherein the measured average traveling speed included in the sensor information is determined to be inappropriate when the threshold value is equal to or greater than the threshold value. The traffic flow estimation means includes
Based on the vehicle type information included in the travel locus information collected by the probe information collection means, calculate the estimated large vehicle mixture rate on the road,
The determination means includes
The measured large vehicle mixing rate that is actually measured by the vehicle sensor and included in the sensor information is compared with the estimated large vehicle mixing rate, and the measured large vehicle mixing rate and the estimated large vehicle mixing rate are 4. The sensor abnormality detection system according to claim 1, wherein when the difference between the two is greater than or equal to a predetermined threshold, the measurement large vehicle mixing rate included in the sensor information is determined to be invalid. . The traffic flow estimation means includes
Based on the travel trajectory information collected by the probe information collecting means, calculate the estimated traffic jam tail position on the road,
The determination means includes
The measured traffic jam tail position actually measured by the vehicle sensor and included in the sensor information is acquired and compared with the estimated traffic jam tail position, and a difference between the measured traffic jam tail position and the estimated traffic jam tail position is predetermined. 5. The sensor abnormality detection system according to claim 1, wherein the measurement traffic tail position included in the sensor information is determined to be invalid when the threshold is equal to or greater than the threshold value. The estimated traffic flow estimated by the traffic flow estimating means is calculated for each of a plurality of lanes of the road,
6. The sensor abnormality detection system according to claim 1, wherein the determination unit determines whether or not the measured traffic flow is appropriate for each lane of the road. Collecting travel locus information transmitted from a plurality of vehicles traveling on a road;
A sensor information collecting step for collecting sensor information on traffic flow of the road measured by a vehicle sensor installed on the road;
Estimating the traffic flow of the road based on the collected travel locus information;
Determining whether or not the sensor information is valid by comparing the estimated traffic flow with the sensor information of the same time period collected on the date of the estimation. What to do on your computer
A method characterized by. Means for obtaining an estimated traffic flow of the road obtained based on travel locus information transmitted from a plurality of vehicles traveling on the road;
Means for obtaining sensor information relating to traffic flow of the road measured by a vehicle sensor installed on the road;
A determination unit configured to determine whether or not the sensor information is valid by comparing the estimated traffic flow with the sensor information of the same time period collected on the day of the estimation;
Sensor abnormality detection device characterized by the above. Obtaining an estimated traffic flow of the road obtained based on travel locus information transmitted from a plurality of vehicles traveling on the road;
Obtaining sensor information relating to traffic flow on the road measured by a vehicle sensor installed on the road;
Determining whether the sensor information is valid by comparing the estimated traffic flow with the sensor information of the same time period collected on the date of the estimation. To do
A computer program characterized by the above.

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