KR102203569B1 - Method and system for evaluating traffic signal operation based on communication data - Google Patents

Abstract

The present invention is a data collection step of collecting communication data from a plurality of individual vehicles; A data processing step of processing the collected communication data; Calculating a signal operation index based on the collected and processed communication data; And evaluating the appropriateness of signal operation based on the calculated signal operation index, wherein the signal operation index includes a total delay time for each intersection approach, a relative delay for each approach road, a green time arrival rate, and a straight forward linkage rate. It relates to a communication data-based signal operation evaluation method, characterized in that.
The communication data-based signal operation evaluation method and evaluation system of the present invention calculates an index for evaluating signal operation by processing and analyzing the communication data collected from a plurality of individual vehicles, and provides a system for monitoring these indexes. The time and cost required for signal operation evaluation can be minimized and the accuracy can be improved dramatically.

Description

Communication data-based signal operation evaluation method and evaluation system {METHOD AND SYSTEM FOR EVALUATING TRAFFIC SIGNAL OPERATION BASED ON COMMUNICATION DATA}

The present invention relates to a signal operation evaluation method and evaluation system, and more specifically, by processing and analyzing communication data collected from a plurality of individual vehicles, evaluating the appropriateness of signal operation, present time distribution, and present order, and monitor the result. It relates to the evaluation method and evaluation system.

In general, urban area Intelligent Transportation System (ITS) is a traffic management system consisting of a traffic information service that collects and processes traffic information from street sections in a city and provides a signal control system that optimizes traffic signals. Says the system. Traffic information service induces safe driving by allowing drivers to use traffic communication information or traffic-related knowledge in advance. That is, the traffic information service provides the driver with information on road congestion, construction, accidents, and control, so that a bypass road can be selected according to the traffic situation. Through this, the traffic information service can minimize direct and indirect loss costs by improving traffic communication according to the effect of dispersing traffic, reducing travel time by selecting the optimal route, and preventing accidents according to prior knowledge of dangerous situations such as accidents.

Furthermore, the efficient operation and management of urban road traffic depends on the efficiency of signal operation. Up to now, the evaluation of signal operation has been carried out by analyzing the data of the traffic volume for each direction of the approach road. Since rotational traffic volume data for each direction of access road cannot be collected mechanically and can only be collected by manpower, it has been costly and time consuming to collect data. Therefore, there is a limitation that accurate signal operation evaluation is difficult because only partial evaluation has been performed intermittently for signal operation.

The present inventor came to complete the present invention to provide a system capable of evaluating signal operation by processing and analyzing individual vehicle data that has been extensively collected and accumulated under an intelligent transportation system.

The problem to be solved by the present invention is to process and analyze communication data collected from a plurality of individual vehicles to calculate indicators capable of evaluating signal operation, and to provide an evaluation method and evaluation system capable of monitoring these indicators. .

One aspect of the present invention is a data collection step of collecting communication data from a plurality of individual vehicles; A data processing step of processing the collected communication data; Calculating a signal operation index based on the collected and processed communication data; And evaluating the appropriateness of signal operation based on the calculated signal operation index, wherein the signal operation index includes a total delay time for each intersection approach, a relative delay for each approach road, a green time arrival rate, and a straight forward linkage rate. It relates to a communication data-based signal operation evaluation method, characterized in that.

In addition, the travel time regression equation separated for each approach route of each intersection is represented by Equation 1 below, and the total delay time for each intersection approach route and the relative delay for each approach route are expressed by Equations 2 and 3 below, respectively. It features.

[Equation 1]

[Equation 2]

[Equation 3]

n = the number of each access road at the intersection (from the north access road (n = 1) in clockwise order),

an = slope of the regression equation for access road n,

bn = the constant of the regression equation for the nth access route,

t = communication time of upstream intersection,

tsn = relative time to the signal period of the upstream intersection where delay starts to occur

ten = relative time to the signal period of the downstream intersection where the delay begins to occur

In addition, in the data collection step, the communication data of the individual vehicle is collected through short-range dedicated communication (DSRC) between the roadside base station installed at the intersection and the vehicle terminal of the individual vehicle passing through the intersection, and the collected communication data is encrypted. Communication ID (ID) of individual vehicles, communication time of upstream intersection, communication time of downstream intersection, collection date, day code, time code (hr), minute (second) code (min, sec), and section travel time can be included. have.

In addition, the data processing step includes processing the collected communication data and assigning a signal flag and a movement flag to each individual vehicle, and the signal label assignment is performed by communicating at an upstream intersection. The time is converted into a relative time for the signal period of the upstream and downstream intersections, and based on the converted relative time, a red flag is given if it falls within the red time when traffic is prohibited in the signal period of the intersection. It is characterized in that a green flag is assigned when it corresponds to the possible green time.

Another aspect of the present invention is a signal controller for controlling a traffic light for controlling the flow of a vehicle passing through an intersection and outputting signal information; Roadside base station; Vehicle terminal; A short-distance dedicated communication device between the roadside base station and the vehicle terminal; It relates to a signal operation evaluation system comprising an ITS center for evaluating and controlling signal operation according to the present invention based on communication data of individual vehicles collected through the short-distance dedicated communication and signal information received from the signal controller, wherein Signal operation evaluation includes a data collection step of collecting communication data from a plurality of individual vehicles; A data processing step of processing the collected communication data; Calculating a signal operation index based on the collected and processed communication data; And evaluating the appropriateness of signal operation based on the calculated signal operation index.

The communication data-based signal operation evaluation method and evaluation system of the present invention calculates an index for evaluating signal operation by processing and analyzing the communication data collected from a plurality of individual vehicles, and provides a system for monitoring these indexes. The time and cost required for signal operation evaluation can be minimized and the accuracy can be improved dramatically.

1 is a flowchart of a method for evaluating signal operation based on communication data according to an embodiment of the present invention.
2 is a conceptual diagram illustrating a relative time and signal label for a signal period.
3 is a conceptual diagram for explaining the provision of a movement flow mark.
4 is a graph showing the total delay time for each approach road per signal period of an intersection from the travel time profile for each approach road.
5 is a graph illustrating a method of calculating a green time arrival rate.
6 shows a screen configuration of an operating terminal on which data analysis results are displayed.
7 schematically shows the configuration of a communication data-based signal operation evaluation system according to an embodiment of the present invention.

The terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention, and thus various alternatives that can be substituted for them at the time of application It should be understood that there may be equivalents and variations.

1 is a flowchart illustrating a method for evaluating signal operation based on communication data according to an embodiment of the present invention.

Referring to Figure 1, the communication data-based signal operation evaluation method according to an embodiment of the present invention comprises a data collection step (S10) of collecting communication data from a plurality of individual vehicles; A data processing step (S20) of processing the collected communication data; Calculating a signal operation index based on the collected and processed communication data (S30); And evaluating the appropriateness of signal operation based on the calculated signal operation index (S40).

In the data collection step (S10), a dedicated short-range communication (Dedicated Short) between the Road Side Equipment (hereinafter referred to as'RSE') installed at the intersection and the on-board equipment (hereinafter referred to as'OBE') of an individual vehicle passing through the intersection. It includes collecting communication data of individual vehicles through Range Communications (hereinafter'DSRC').

As an embodiment, the communication data of the individual vehicle collected in the data collection step (S10) is (1) the encrypted communication ID (ID) of the individual vehicle, (2) the communication time at the upstream intersection, and (3) the communication time at the downstream intersection. , (4) collection date, (5) weekday code, (6) time code (hr), (7) minute (second) code (min, sec), (8) section travel time, and the like.

In the present invention, "upstream intersection" refers to an entry intersection through which an individual vehicle to be subjected to section travel time and signal delay estimation has passed just before, and "downstream intersection" is a relative concept meaning an exit intersection. Upstream intersection communication time refers to the time when communication data of individual vehicles is recorded through DSRC at the roadside station installed at the upstream intersection, and communication data of individual vehicles is recorded through DSRC at the roadside intersection installed at the downstream intersection. Means the time of day. Section travel time can be calculated using the time difference between the communication time of the upstream intersection and the communication time of the downstream intersection collected from individual vehicles.

Individual vehicle communication data collected at the roadside station can be stored as a DB in the Intelligent Transport System Center (hereinafter referred to as'ITS Center') that controls the system by collecting the overall traffic flow control and corresponding traffic information. , It can be continuously accumulated in real time and converted into big data. The communication data converted into big data in this way can improve the reliability of estimation of travel time and delay by mitigating the deviation of collected data.

A brief description of the DSRC is as follows. The DSRC is a standard method and uses a frequency band of 5.8 GHz for short-range wireless communication. The DSRC is a new short-range wireless communication means introduced to collect traffic information. It is a communication requirement for traffic information and control system application by collecting location information and time information through communication between the vehicle terminal (OBE) and the roadside base station (RSE). Can satisfy them.

The data processing step (S20) includes processing communication data collected from a plurality of individual vehicles and providing a signal flag and a movement flag to each of the individual vehicles.

The signal sign assignment converts the communication time of individual vehicles collected at the roadside station into a relative time relative to the signal period of the upstream or downstream intersection, and displays a sign indicating whether the signal is delayed at the intersection based on the converted relative time. To give. In order to give the signal mark, the relative time of the individual vehicle must first be calculated.

In the present invention, the relative time can be divided into a first relative time and a second relative time. The first relative time refers to the time at which the communication time at the upstream intersection is converted relative to the signal period at the upstream intersection, and can be defined as the communication time measured from an individual vehicle minus the time at which the signal cycle starts at the intersection. have.

For example, assuming that the signal period of the upstream intersection is 120 seconds and the signal is displayed from 08:00, the first relative time of the vehicle whose actual communication time at the upstream intersection is 8:00:27 is 27 seconds, The first relative time of the vehicle whose actual communication time is 8:01:27 is 87 seconds.

The second relative time refers to the time obtained by converting the actual communication time at the upstream intersection with respect to the downstream intersection signal period. For example, assuming that the signal period of the downstream intersection is 120 seconds and the signal is displayed from 07:59, the second relative time of the vehicle whose actual communication time at the upstream intersection is 8:00:27 is 87 seconds, The second relative time of the vehicle whose actual communication time is 8:01:27 is 27 seconds.

After converting the actual communication time to the relative time, it is possible to give a signal mark by determining whether there is a delay at the intersection of individual vehicles based on the converted relative time. 2 is a conceptual diagram illustrating the relative time and signal label for a signal period. 2, the actual communication time (t) measured from an individual vehicle is converted into a relative time (T) for the signal period (S) of an intersection, and it is determined which signal the converted relative time corresponds to in the signal period. This can be used to give signal signs. Therefore, for vehicles whose actual communication time is t3 and t5, respectively, even if t5 is later than t3 (t5>t3), if their actual communication time difference is equal to one cycle time of the corresponding intersection signal period (t5-t3= S), their relative time can be calculated equally as T5.

As an embodiment, when judging by the relative time for the upstream and downstream intersection signal period, if the intersection communication time corresponds to the red time when traffic is prohibited in the signal period, a red flag is assigned as the signal sign. When this possible green time is reached, a green flag can be assigned as a signal sign. Typically, signals are divided into three colors: green, yellow, and red, but in the present invention, "red" and "green" are applied by applying the concept of effective green time, which is an actual movable time, and effective red time, which is an unmovable time. It is decided to separate and indicate.

As an example, if the signal period of the upstream intersection is 120 seconds, and the signal is given in green for 50 seconds, yellow for 10 seconds, and red for 60 seconds, a green flag is displayed on a vehicle whose first relative time is measured as 47 seconds. It is assigned, and a red flag is displayed on a vehicle having a first relative time of 80 seconds.

In addition, if the signal period of the downstream intersection is 120 seconds, the signal is given in green for 50 seconds, yellow for 10 seconds, and red for 60 seconds, a green flag is given to the vehicle whose second relative time is measured as 47 seconds. A red flag is displayed on a vehicle with a second relative time of 80 seconds.

The movement flow mark is assigned to each vehicle by determining whether a vehicle is going straight, turning left, or turning right based on the actual communication time of individual vehicles collected at the roadside station.

3 is a conceptual diagram for explaining the provision of a movement flow mark. Referring to FIG. 3, a vehicle that turns left after passing a downstream intersection stores communication records sequentially measured at RSE 1, RSE 2, and RSE 3, and the vehicle that goes straight after passing the downstream intersection is RSE 1, RSE 2, and Communication records measured sequentially in RSE 4 are stored.

Accordingly, a moving flow can be classified by giving a straight ahead sign as a moving flow sign, a left turning sign to a left-turning vehicle, and a right turning sign to a right-turning vehicle.

Processed data including the first relative time, second relative time, signal sign, and movement flow sign secured through the data processing step (S20) may be converted into a DB and stored in the ITS center like the first collected data. Of course, it can be accumulated and stored in real time to convert into big data.

The step of calculating the signal operation index (S30) is a step of calculating the total delay time for each intersection approach road, the relative delay for each approach road, the green time arrival rate, and the straight forward linkage rate based on the collected and processed communication data. to be.

4 is a graph showing the total delay time for each approach road per signal period of an intersection from the travel time profile for each approach road.

The total delay time for each approach road at an intersection is calculated by integrating the regression equation for the travel time for each approach road and the arrival time at the upstream intersection, and the relative delay for each approach road is the total delay time for each approach road as a signal of the entire intersection It is calculated by dividing by the total delay time (sum of total delay time for each approach route) that occurs per cycle (1 cycle).

The travel time regression equation separated for each approach route of each intersection is expressed by Equation 1 below, and the total delay time for each intersection access route and the relative delay for each access route are expressed by Equations 2 and 3 below, respectively.

[Equation 1]

[Equation 2]

[Equation 3]

n = the number of each access road at the intersection (from the north access road (n = 1) in clockwise order),

a _n = slope of the regression equation for n approaches,

b _n = the constant of the regression equation for the nth access route,

t = communication time of upstream intersection,

t _sn = relative time to the signal period of the upstream intersection where the delay begins to occur

t _en = relative time to the signal period of the downstream intersection where the delay begins to occur

5 is a graph illustrating a method of calculating a green time arrival rate. The green time arrival rate is calculated by analyzing the relative time and travel time of the upstream intersection signal period among the collected individual vehicle communication data, and is calculated as the ratio of the vehicle passing through without signal delay to the total communicated vehicle. The approach road with a high arrival rate during the green hour means that the intersection traffic is better than other access roads. When the straight and left turn signals are given separately, the arrival rate of each green hour is calculated to determine the traffic condition for each approach route.

The straight forward linkage rate refers to calculating the ratio of the signal period when arriving at the upstream intersection and the ratio of vehicles arriving at the green time of the intersection to be analyzed, limited to vehicles going straight for each approach route. The straight forward linkage rate is an index to determine whether the signal periods of two intersections are well linked. The linear interlocking rate is divided into A and B, and is defined as follows.

Straight interlock rate A: The ratio of vehicles that arrive in the green time of the upstream intersection among straight vehicles and the intersection to be analyzed also arrives in the green time (when passing without waiting for a signal)

Straight interlock rate B: The ratio of vehicles arriving at the red hour of the upstream intersection among straight vehicles arriving at the green hour of the intersection to be analyzed (one signal waits at the upstream intersection only)

The step of evaluating the appropriateness of signal operation (S40) means evaluating the signal cycle state of the intersection to be analyzed based on the calculated signal operation index.

The optimal state to be achieved by the above-described signal operation index value is as follows, and it is preferable to adjust the current distribution of the intersection to be analyzed so as to satisfy the optimal state of the indexes 1 to 5 below.

(Indicator 1) Total delay time: minimized

(Indicator 2) Relative delay by approach route: Minimize the difference in relative delay by approach route

(Indicator 3) Green Hour Arrival Rate: Maximize Ratio

(Indicator 4) Linear interlock rate A: Maximized

(Indicator 5) Straight linkage B: Minimization

6 shows a screen configuration of an operating terminal on which data analysis results are displayed. At the top of the screen, the relative delay (indicator 2) and the green time arrival rate (indicator 3), which mean the reduction in travel time (lag time) in each direction (by approach direction) at the intersection with the road to be observed, are visually displayed. The value of the total delay time (indicator 1) is the sum of the relative delay (indicator 2) for each access route.

The graph at the bottom left of the screen shows the change in the number of vehicles arriving in the green hour by intersection, and the green hour arrival rate (indicator 3) is displayed in the unit of time desired for each intersection.

The graph at the bottom right of the screen shows the linear interlocking rates A and B (indicators 4 and 5) for each approach route. The gray dots in the graph indicate the relative arrival times of vehicles on the east access road (EB) according to the green and red periods of the intersection signal.

7 schematically shows the configuration of a communication data-based signal operation evaluation system according to an embodiment of the present invention.

Referring to FIG. 7, the signal operation evaluation system 100 includes a signal controller 110 for controlling a traffic light for controlling a flow of a vehicle passing through an intersection and outputting signal information; Roadside base station 120; A vehicle terminal 130; A short-distance dedicated communication device 140 between the roadside base station 120 and the vehicle terminal 130; It may include an ITS center 150 that evaluates and controls signal operation according to the present invention based on communication data of individual vehicles collected through short-distance dedicated communication and signal information received from the signal controller 110.

The signal operation evaluation system according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , If a person of ordinary skill in the field to which the present invention belongs, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later belong to the scope of the invention. .

Claims (5)

A data collection step of collecting communication data from a plurality of individual vehicles;
A data processing step of processing the collected communication data;
Calculating a signal operation index based on the collected and processed communication data; And
Including the step of evaluating the appropriateness of the signal operation based on the calculated signal operation index,
The signal operation indicator includes the total delay time for each approach road at the intersection, the relative delay for each approach road, the arrival rate at green time, and the straight forward linkage rate
The travel time regression equation separated for each approach road of each intersection is calculated by Equation 1 below, and the total delay time for each intersection approach road and the relative delay by approach route are calculated by the following Equations 2 and 3, respectively,
The green time arrival rate is the ratio of the vehicle that passed without signal delay to the total vehicle communicated by analyzing the relative time and travel time of the upstream intersection signal period among the collected individual vehicle communication data,
The straight forward linkage rate includes the straight forward linkage rate A and the straight forward linkage rate B, and the straight forward linkage rate A is the ratio of vehicles arriving at the green time of the upstream intersection among the straight cars and arriving at the intersection to be analyzed at the green time (pass without waiting for a signal). In case of), the straight forward linkage ratio B is the ratio of vehicles arriving at the red hour of the upstream intersection among the straight vehicles arriving at the green hour of the intersection to be analyzed (the signal waits only at the upstream intersection),
The adequacy evaluation is a method for evaluating signal operation based on communication data, characterized in that the total delay time for each approach route, the relative delay for each approach route, and the straight forward linkage rate B are minimized, and the green time arrival rate and the straight forward linkage rate A maximize:
[Equation 1]

[Equation 2]

[Equation 3]

n = the number of each access road at the intersection (from the north access road (n = 1) in clockwise order),
a _n = slope of the regression equation for access road n,
b _n = the constant of the regression equation for access road n,
t = communication time of upstream intersection,
t _sn = relative time to the signal period of the upstream intersection where delay starts to occur
t _en = the time relative to the signal period at the downstream intersection where the delay begins to occur.
delete The method of claim 1,
In the data collection step,
The communication data of the individual vehicles is collected through short-range dedicated communication (DSRC) between the roadside base station installed at the intersection and the vehicle terminal of the individual vehicle passing through the intersection,
The collected communication data is the encrypted communication ID (ID) of the individual vehicle, the communication time at the upstream intersection, the communication time at the downstream intersection, the date of collection, the day of the week code, the time code (hr), the minute (second) code (min, sec), And a signal operation evaluation method based on communication data, comprising a section travel time.
The method of claim 1,
The data processing step includes processing the collected communication data to give a signal flag and a movement flag to each individual vehicle,
The signal sign assignment converts the time communicated at the upstream intersection into a relative time relative to the signal period of the upstream and downstream intersections, and based on the converted relative time, it is red when the traffic is prohibited in the signal period of the intersection. A method for evaluating signal operation based on communication data, characterized in that a red flag is assigned and a green flag is assigned when a green time is available for traffic.
delete

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