JP2005339286A - Start condition measuring apparatus of stop vehicle at intersection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a start condition measuring method and its apparatus of a stop vehicle at an intersection capable of collecting and providing information on signal control in order to make effective use of a road by detecting and measruing micro fluctuations of a group of vehicle stopped by a a red light in a short time when the signal turns green. <P>SOLUTION: The start condition measuring apparatus of stop vehicles at the intersection is provided with: a means for measuring vehicles which shift to the start condition by the green light flashing of a group of vehicles under stop condition in a section reaching a stop line at the intersection; and a means for detecting that its passing traffic flow has reached a normal state of a target road. The apparatus is also provided with: a means for measuring time spent from when the stop vehicles gradually begin to start to when the respective vehicles reache the intersection; and a means which measures a time interval of the vehicles passing the stop line and measures a period of time until its value reaches a specified time interval. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a start state measuring apparatus that measures a start state of a stopped vehicle at an intersection, a traffic flow interruption, and the like so that signal control suitable for a road condition can be performed.

Conventionally, it is known that the traffic state of an inflow path to an intersection is imaged in a plane, the image signal is signal-processed to predict optimal traffic control at the intersection, and a traffic light installed at the intersection is controlled ( Hereinafter, it is referred to as “prior art 1” (for example, see Patent Document 1). This prior art 1 measures the existence position and speed of vehicles included in the area captured by the image sensor, predicts and calculates the traffic flow at the intersection, the amount of vehicle traffic, and the number of remaining vehicles. Based on the above, the traffic light is optimally controlled.
Further, an invention of a vehicle interval measurement method by the inventor of the present invention is known (hereinafter referred to as “Prior Art 2”, see Patent Document 2). The invention of the vehicle interval measuring method of this prior art 2 avoids a collision with a straight vehicle facing the vehicle or the like, and obtains timing data for making it possible to make a right turn at an intersection safely. The present invention relates to a method for measuring an interval.
JP-A-11-126296 JP 2004-54464 A

The invention of Prior Art 1 measures the position and speed of the vehicle included in the area captured by the image sensor, but how to measure the position and speed of the vehicle is as follows. There is no specific disclosure, and even if a known measuring means is used, it is technically difficult to accurately detect a vehicle that covers a wide range from a stopped vehicle to a high-speed traveling vehicle.
Further, the invention of Prior Art 2 measures the correlation between the distance between straight vehicles and a right turn vehicle at a certain intersection, so that the vehicle or the like avoids a collision with the opposite straight vehicle and turns right at the intersection safely. The purpose of the present invention is to make it possible, and does not collect or provide information that contributes to signal control by measuring the start state of a stopped vehicle at an intersection as in the present invention.

  The present invention collects information that contributes to signal control for effective use of roads by detecting and measuring micro fluctuations in a short time when a vehicle group in a stopped state is changed by a red signal. An object of the present invention is to provide a method and apparatus for measuring the starting state of a stopped vehicle at an intersection that can be provided.

In order to achieve the above object, the invention according to claim 1 relating to the start state measuring device for a stopped vehicle at an intersection of the present invention is brought into a start state by lighting a green signal of a vehicle group that is in a stop state in a section up to the stop line at the intersection. It is characterized by comprising means for measuring a moving vehicle and means for detecting that the passing traffic flow has reached a steady state of the target road.
The invention described in claim 2 is characterized in that in the invention described in claim 1, there is provided means for measuring the time required for each vehicle to start an intersection and reach each intersection. It is a feature.
The invention according to claim 3 is the invention according to claim 1, further comprising means for measuring a time interval of the vehicle passing through the stop line and measuring a period until the value reaches a certain time interval. It is characterized by that.
According to a fourth aspect of the present invention, there is provided a means for measuring a vehicle that shifts to a start state by lighting a green signal of a vehicle group that is in a stopped state in a section up to a stop line at an intersection, and the passing traffic flow is steady on the target road. And a means for detecting that the vehicle has reached a state. The measured values are recorded and accumulated, and are used for signal control by analyzing the usage situation and characteristics of the target road.

The present invention has the following excellent effects.
(1) Collecting information that contributes to signal control for effective use of roads by detecting and measuring micro fluctuations in a short period of time when a red light changes to a group of vehicles that are stopped. It can be provided.
(2) The usage status and characteristics of the target road can be analyzed from the collected data obtained by the measurement.
(3) Collected data obtained by measurement depends on the size and structure of each intersection, the weather at that time, and the traffic volume. Can be used. Therefore, the characteristics of each intersection can be compared with the characteristics of other intersections, and can be used for signal control at the intersection.

A best mode for carrying out a method and an apparatus for measuring a starting state of a stopped vehicle at an intersection according to the present invention will be described below with reference to the drawings based on the embodiments. FIG. 1 is a diagram showing an overall outline around an intersection according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the system configuration. Note that each functional unit in FIG. 2 can also be referred to as functional means for performing a predetermined function.
[Example]

  FIG. 1 is a diagram showing an overall outline of the vicinity of an intersection in the present embodiment, and a television camera 5 is installed at a high place overlooking an inflow path 3 and a traffic light 4 including a stop line 2 of the intersection 1 to be measured. Has been. The detecting means is not limited to a television camera, and any sensor such as a sensor embedded in the road surface may be used as long as it has a function capable of being detected in the same manner as the television camera. Hereinafter, an example using a television camera will be described.

The television camera 5 is connected to a personal computer 6 (hereinafter simply referred to as “computer 6”) directly or via a VTR.
As shown in FIG. 2, an image input board 7 and dedicated application software (hereinafter referred to as “dedicated software”) are built in the computer 6. As this dedicated software, software developed based on known software having an image processing function for performing background estimation using the Kalman filter theory is used.
The computer 6 is connected to the traffic control center 8.

Hereinafter, the measurement of the start state of the stopped vehicle at the intersection by the present apparatus will be described step by step with reference to FIG.
(Step 1)
The inflow path 3 including the stop line 2 of the intersection 1 in a state where no vehicle is present is photographed by the TV camera 5 and recorded on the VTR (S1).
(Step 2)
The traffic flow in the inflow path 3 including the stop line 2 at the intersection 1 is photographed by the TV camera 5 and recorded on the VTR (S2).
(Step 3)
The video signal of the traffic flow in step 2 is input to the image input board 7 of the computer 6 (S3).
(Step 4)
On the processing screen, a detection area on the road surface, for example, an inflow lane including a stop line is designated by drawing a boundary line with a mouse (S4).
(Step 5)
A screen when a vehicle or the like does not exist in the detection area specified in step 4 is specified as an initial background screen (S5).

(Step 6)
By continuing the dedicated software, the difference detection processing unit 9 approximates and extracts, for example, a rectangular area (location) between the background screen and the input screen. At the same time, the four corners of the extracted rectangle are output as numerical values (pixel values on the image) indicating the coordinates on the image. Here, the coordinates of the four corners are positions of four points corresponding to both ends of the front bumper and both ends of the rear bumper of the vehicle, and four points are output as one set (S6). An output example is shown in FIG.
In the dedicated software, only the difference detection is performed, and the user determines whether the vehicle is a subsequent vehicle and performs various calculations.

(Step 7)
The vehicle detection processing unit 10 processes the numerical values of each set output as one set of 4 points in step 6 as described below to extract only those corresponding to the vehicle and determine that it is a vehicle (S7).
Part 1: According to perspective, distant objects appear in a small shape and large in a close view. Therefore, the size of the large and small rectangles existing on the image is on the road and the size according to the distance. A rectangle having the same is determined as a vehicle.
Part 2: Numeric data corresponding to the distance of the road, such as large vehicles, ordinary passenger cars, and motorcycles, is stored and compared with it to determine the vehicle.
With the above processing, a determination result as shown in FIG. 5 is obtained from the quadrilateral numerical table shown in FIG. Here, k1, k2, k3, k6, k7, and k9 shown at the left end of FIG. 4 indicate times 380, 381, 399, 404, 405, and 412 respectively, and FIGS. 7 to 12 show the respective times. Is an image processing screen corresponding to In FIG. 5, a vehicle and a vehicle that is not a vehicle are determined from the size and shape of the quadrilateral.

(Step 8)
In the vehicle tracking unit 11, for example, by the processing of step 7 on each input frame (each image every 1/30 second in this apparatus) for a certain period of time such as 30 seconds before and after the signal switches from red to blue. A numerical table corresponding to each vehicle obtained is created (S8). The numerical table is shown, for example, as the number of each frame and the coordinates of four rectangular points as shown in FIG. At that time, a numerical table indicating the number of each frame and the vehicle is taken as a pair.

(Step 9)
In the actual position conversion unit 12, the detected numerical value is converted into the position of the actual road (S9). For this reason, a correspondence table with the position of the actual road corresponding to each pixel, for example, a distance based on the stop line as shown in FIG. 3, is created in advance.
FIG. 6 shows the road position corresponding to the vehicle quadrilateral tip (Row 2) converted into the distance from the stop line.

(Step 10)
In the determination unit 13, each vehicle is tracked from the numerical table shown in FIG. As a result, even if there are a plurality of vehicles on the same screen, each vehicle can be identified and tracked. Even if it is erroneously determined that the vehicle is a vehicle from the shape and size of the quadrilateral in step 7, the quadrangle that does not move is removed as a non-vehicle here.
From such tracking of the position of each vehicle, the following parameters can be detected by a simple calculation.
(1) Position of each vehicle at each time (both ends of front bumper and both ends of rear bumper)
(2) The speed of each vehicle (3) The head distance of each vehicle before and after each time (4) The head time of each vehicle at a fixed position such as a stop line (5) The signal changed from red to blue And the time when the vehicle starts and passes the stop line

(Step 11)
From the above calculation results, the time from when the vehicle starts until the traffic flow returns to the steady state is known. Here, the steady state means that, for example, the vehicle head interval is measured, and when the value gradually reaches a certain value (usually the driving state of the road) after becoming a green signal, it is determined that the steady state has been reached. . This value is different for each road and can be characterized as the steady state of that road.

As described above, the start state of the stopped vehicle at the intersection can be measured by the present apparatus.
In addition, for example, the timing of signal switching is detected by detecting whether there is a vehicle on the road or no traveling vehicle for one or two specific points such as 50 m and 100 m from the stop line. Can help to consider.

The data thus obtained is collected over a long period of time.
By collecting data representing the driving conditions of general drivers at intersections, such as the start status of stopped vehicles, the time until the stop vehicle passes through the stop line, vehicle head time, speed, etc. Can be used for signal control.

  The above is the traffic information collecting apparatus that detects the vehicle travel locus from the output video information of the TV camera using the dedicated software for the inflow traffic to the intersection. Furthermore, if a TV camera can be installed at a high place overlooking the entire neighborhood of the intersection, it will be possible to collect information on traffic in the four directions flowing into the intersection at the same time, providing valuable information to the traffic control center. Can be conditioned.

  The above collected data depends on the size of each intersection, structure, weather at the time of measurement, and traffic volume. Each collected data has its own characteristics and is useful as basic data for analyzing the characteristics of the intersection. It is. Therefore, these data can be collected, stored as a database, and compared with the characteristics of each intersection to be used for signal control at the intersection.

It is a figure which shows the whole outline vicinity of the intersection which concerns on embodiment of this invention. It is a block diagram which shows the system configuration | structure which concerns on embodiment of this invention. It is a correspondence table | surface of the position of the real road and each pixel which concerns on embodiment of this invention. It is a figure which shows the numerical table of four corners of the quadrangle which concerns on embodiment of this invention. The example of determination of the vehicle using the numerical table of FIG. 4 and a non-vehicle is shown. The position on the road corresponding to the tip of the quadrilateral is converted into the distance from the stop line. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time. It is explanatory drawing based on the photograph image | photographed with the television camera near the intersection at a certain time.

Explanation of symbols

1 intersection
2 Stop line
3 Inflow channel
4 traffic lights
5 TV camera
6 Personal Computer 7 Image Input Board 8 Traffic Control Center 9 Difference Detection Processing Unit 10 Vehicle Detection Processing Unit 11 Vehicle Tracking Unit 12 Real Position Conversion Unit 13 Determination Unit

Claims (4)

  Means for measuring a vehicle that shifts to a start state by lighting a green light of a vehicle group that is in a stop state in a section up to the stop line of the intersection, and means for detecting that the passing traffic flow has reached a steady state of the target road; An apparatus for measuring a starting state of a stopped vehicle at an intersection characterized by comprising:   2. A stop vehicle start state measuring apparatus according to claim 1, further comprising means for measuring a time required for each vehicle to start gradually and each vehicle reaches an intersection.   2. A stop vehicle start state measuring device according to claim 1, further comprising means for measuring a time interval of the vehicle passing through the stop line and measuring a period until the value reaches a certain time interval. . Means for measuring a vehicle that shifts to a starting state by lighting a green light of a vehicle group that is in a stop state in a section to the stop line of the intersection, and means for detecting that the passing traffic flow has reached a steady state of the target road The measured state value is recorded and accumulated, and is used for signal control by analyzing the usage situation and characteristics of the target road.