KR101361671B1 - Variable speed limit system and method - Google Patents

Abstract

The present invention relates to a variable speed control system and method.
The variable speed control system according to the present invention includes a road information receiver, a traffic control speed calculator, a control section length calculator, and a traffic control speed controller. The road information receiver receives road information. The traffic control speed calculating unit is configured to take into consideration the bottleneck area in which the bottleneck is generated through the received road information, considering the usual capacity (Qd), the free speed (Uf) and the bottleneck capacity (Qac) in the bottleneck area. A traffic control speed at an upstream portion of the bottleneck section is calculated. The control section length calculator calculates a control section length to which the traffic control speed is applied based on the traffic control speed. The traffic control speed control unit controls to apply the calculated traffic control speed to a section corresponding to the calculated control section length in the upstream direction from the bottleneck section.
According to such a configuration, by minimizing the speed of the congestion shock wave, the area of the congestion section and the queue length are ultimately reduced, thereby maximizing the amount of traffic passing through, so that unstable traffic flow can be converted into stable traffic flow.

Description

Variable speed control system and method {VARIABLE SPEED LIMIT SYSTEM AND METHOD}

The present invention relates to a variable speed control system and method, and more particularly, to prevent congestion on the upstream part when a bottleneck occurs, to maximize the passing traffic, and to realize a variable that can convert unstable traffic into stable traffic. The present invention relates to a speed control system and method.

The present invention is derived from the research conducted as part of the construction technology innovation project of the Ministry of Land, Transport and Maritime Affairs and the Korea Institute of Construction and Transportation Technology. [Task No.: Technology Innovation A01, Title: Smart Highway Project Development Mainland traffic management technology development during congestion)].

Variable Speed Limit (VSL) limits the speed according to traffic conditions to prevent accidents by reducing the speed difference between vehicles and lanes before reaching the congestion or accident point, and to minimize the total delay zone. One of the continuous flow ITS techniques. In the United States and Europe since the 1960s, speed control for safety and congestion relief, as well as speed control for factors such as weather changes, accidents, school zones, tunnels and bridge sections, Was introduced. Overseas, there are many studies and applications of variable speed control or lane control in M26 roads in the UK, Autobahn in Germany, Sweden, and other developed countries in Europe, and as a continuous flow control technology to improve safety for accident prevention. Perched.

In the case of an event that occupies the road such as an accident in the continuous flow basic section, and the capacity decreases, that is, when the bottleneck occurs, the variable affecting the total delay area occurring upstream of the bottleneck section is a bottleneck duration ( Tb-Ta) and congestion shock waves (W1) due to bottlenecks, and bottleneck shock waves (Wc). The change in the state of traffic flow and the generation of shock wave at the time of bottleneck using the above variables are shown in FIG. 1. The area corresponding to D in the construction diagram in (a) means the total area of delay occurring upstream of the bottleneck section due to capacity disturbances. When the bottleneck occurs, the traffic flow changes from A to D as shown in (b), and congestion is propagated downstream at the speed of W1. As can be seen in the figure, as the bottleneck occurs, the delay section increases, and the passage speed Ud decreases.

On the other hand, in relation to the variable speed control technology, the article "Research on the application of variable speed limit for the prevention of traffic accidents on highways" describes the method of applying the variable speed limit for the purpose of preventing traffic accidents, that is, enhancing safety. Through the analysis of highway and accident data, we construct a probabilistic model of predicting accident risk and propose a method to limit the speed when the probability of accident increases, and the variable speed limit system algorithm based on the deceleration speed according to weather and road conditions. .

However, the paper only suggests the process of how to slow down when the above situation occurs, and the calculation of the control section distance and control time is excluded.

Therefore, there is a need for a variable speed control technology capable of preventing congestion from being increased to an upstream view when a bottleneck occurs, maximizing the amount of passing traffic, and converting unstable traffic into stable traffic.

Thesis "A Study on the Application of Variable Speed Limit for the Prevention of Highway Traffic Accidents" (Source: Journal of Korean Society of Transportation v.26, no.4, 2008. pp.111, 121 / Author: Park Jun-hyung, Hyo-won Hwang, Oh-chul, Jang Myung-soon)

An object of the present invention is to provide a variable speed control technique capable of preventing congestion to the upstream part when a bottleneck occurs, maximizing passing traffic, and converting unstable traffic into stable traffic.

In addition, the present invention aims to enable more accurate control by considering not only how much deceleration should be decelerated when the bottleneck occurs, but also the control section and the control time that deceleration should be made.

In order to achieve this object, the variable speed control system according to the present invention includes a road information receiver, a traffic control speed calculator, a control section length calculator, and a traffic control speed controller. The road information receiver receives road information. The traffic control speed calculating unit is configured to take into consideration the bottleneck area in which the bottleneck is generated through the received road information, considering the usual capacity (Qd), the free speed (Uf) and the bottleneck capacity (Qac) in the bottleneck area. A traffic control speed at an upstream portion of the bottleneck section is calculated. The control section length calculator calculates a control section length to which the traffic control speed is applied based on the traffic control speed. The traffic control speed control unit controls to apply the calculated traffic control speed to a section corresponding to the calculated control section length in the upstream direction from the bottleneck section.

As described above, according to the present invention, after congestion has already occurred due to a factor such as an accident, there is an effect of preventing congestion from being weighted upstream of the bottleneck section.

In particular, by minimizing the speed of the congestion shock wave, the unstable traffic flow can be converted into the stable traffic flow because the area of the congestion zone and the queue length are ultimately reduced to maximize the passing traffic.

In addition, unlike the prior art, more accurate control is possible by considering not only how much the deceleration should occur when the bottleneck occurs, but also the control section and the control time that deceleration should be made.

In addition, when applied at a stepwise speed compared to the case of applying the passage control speed at a single speed, the overall control section length can be shortened to reduce the congestion dispersion section to the upstream part. Therefore, a strategy to control the passage speed control step by step in the section corresponding to the control section length from the bottleneck section to the upstream direction can be a practical application to lower the average passage speed of the upstream section of the bottleneck section.

Figure 1 (a) is a diagram showing the shock wave and the generation of delay on the construction diagram when the capacity disintegration.
Figure 1 (b) is a view showing a state change of traffic flow during capacity disintegration.
2 is a view showing a schematic configuration of a variable speed control system according to an embodiment of the present invention.
3 (a) is a diagram illustrating a traffic flow-density relationship when a variable speed control system is applied.
FIG. 3B is a diagram showing the change of the shock wave and the total retardation area when the variable speed system is applied.
4 (a) is a diagram illustrating a traffic flow-density relationship in stepwise control.
4 (b) is a view showing the interval-time relationship in the step-by-step control on the construction diagram.
5 is a view showing a schematic flow of a variable speed control method according to an embodiment of the present invention.
6 is a view showing a result of changing the average speed for each scenario.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Further, in the description of the embodiments of the present invention, specific values are merely examples, and exaggerated values may be presented for convenience and understanding of the present invention.

<Description of System>

2 is a view showing a schematic configuration of a variable speed control system according to an embodiment of the present invention.

Referring to FIG. 2, the variable speed control system 100 according to the present invention includes a road information receiver 101, a traffic control speed calculator 102, a control section length calculator 103, and a traffic control speed controller 104. It includes.

The road information receiver 101 receives road information such as road location information, road speed limit, traffic information, environmental information, and the like.

The traffic control speed calculating unit 102 considers the usual capacity Qd, the free speed Uf, and the capacity Qac at the bottleneck when the bottleneck is detected through the received road information. To calculate the traffic control speed Uvsl upstream of the bottleneck section. Here, the usual capacity is the traffic volume when no bottleneck occurs, and the free speed means the average passage speed or the speed limit when the bottleneck does not occur. The traffic control speed calculating unit 102 calculates the traffic control speed Uvsl to maintain the density Kd based on the inflow traffic flow rate (entry traffic volume per hour), but the minimum speed of the bottleneck section at the free speed Uf. It is calculated by the following equation between (Ud).

Uvsl: traffic control speed

Qac: bottleneck capacity

Kd: density corresponding to inflow rate

Qd: usual capacity

Uf: free speed

Ud: Congestion rate without control

When conceptually representing the traffic flow-density relationship when the variable speed control system 100 is applied, it is shown in FIG. 3 (a), and when the bottleneck occurs, the traffic flow is changed from A (the usual state) to D (the bottleneck state). However, the present invention calculates the traffic control speed so that the density of A and the bottleneck capacity of D can be maintained, that is, changed to the state B on the drawing.

On the other hand, in order to control the congestion propagation upstream of a predetermined unit time (passage control time) based on the calculated passage control speed, the control section length calculation unit 103 controls to apply the passage control speed based on the passage control speed. The section length CS is calculated by calculating the product of the traffic control speed and the traffic control time in the upstream portion. At this time, the traffic control time Tc is a bottleneck from the time Ts at which traffic control is started by the congestion shock wave W1 due to the bottleneck to the upstream part by the bottleneck clearing shock wave Wc after the bottleneck is eliminated. Up to the end point Te of all of these calculations, the following equation is calculated.

Tc: traffic control time

Ts: Start of traffic control

Te: End of traffic control

Xqueue: queue length

Wc: Bottleneck Shockwaves

Tb: Bottleneck

Ta: the beginning of the bottleneck

W1: congestion shock wave due to bottleneck

When the variable speed control system 100 is applied, the change in the congestion shock wave and the total retardation area is shown in FIG. In general, as the traffic control speed decreases, the average density of the upstream portion increases, so that the speed of the congestion shock wave is set to 0 to prevent the rapid increase of the congestion shock wave during control, but the traffic can be maximized in consideration of the reduced capacity. It is desirable to calculate the control speed. Therefore, it can be seen that when the velocity of the congestion shock wave is 0, the total retardation area decreases as compared with the conventional one.

The traffic control speed control unit 104 controls to apply the calculated traffic control speed to the section corresponding to the calculated control section length in the upstream direction from the bottleneck section. That is, the traffic control speed control unit 104 displays the traffic control speed in the field facilities such as an electronic billboard installed on the road so that the traffic control speed is applied to the vehicle, or provides the traffic control speed to the personal terminal based on wireless communication. Regardless of the installation location of the facility can be made.

As described above, the present invention has an effect of preventing congestion from being weighted upstream of the bottleneck section after congestion has already occurred due to factors such as an accident. In particular, by minimizing the speed of the congestion shock wave, the unstable traffic flow can be converted into the stable traffic flow because the area of the congestion zone and the queue length are ultimately reduced to maximize the passing traffic. In addition, unlike the prior art, more accurate control is possible by considering not only how much the deceleration should occur when the bottleneck occurs, but also the control section and the control time that deceleration should be made.

On the other hand, the variable speed control system 100 described above maintains the upstream speed (Uvsl) in a way to prevent the propagation upstream of the congestion by performing a predetermined time control at a single speed, the maximum Kd '(Fig. 3 (a) ) Is a method of spatially dispersing congestion with a density of The method has a disadvantage in that when the bottleneck time becomes long, the control section distance CS is rapidly increased in order to cancel the congestion shock wave. Accordingly, the present invention considers a method of controlling the congestion shock wave by applying the traffic control speed in multiple stages to the control target traffic Qd-Qac during the same unit time Tc.

To this end, the variable speed control system 100 according to the present invention further includes a section divider 105 for dividing the passage control time obtained above into two or more sections.

The traffic control speed calculating unit 102 calculates different traffic control speeds in the divided sections, and the traffic control speeds for each stage are based on each step. Qac) and the usual capacity Qd are calculated and calculated by the following equation.

Un: Traffic control speed of n steps

Qac: bottleneck capacity

Qd: usual capacity

Un-1: Traffic control speed of previous step of n steps

Uf: free speed

Ud: Congestion rate without control

In addition, the control section length calculation unit 103 calculates the control section length by the following equation.

 CS: control section length

Tc: traffic control time

Uf: free speed

Qac: bottleneck capacity

Qd: usual capacity

n: step

Looking at the basic concept of determining such a step-by-step control speed is shown in FIG. (a) is a diagram conceptually illustrating the traffic flow-density relationship in the stepwise control, and (b) is a diagram conceptually illustrating the section-time relationship in the stepwise control on the construction diagram.

Referring to FIG. 4, when the passage control speed is applied at a single speed as described above (see FIG. 3), the final passage control speed Un is lower than the initial passage control speed U1. The control density K becomes relatively high. However, it is possible to shorten the overall control section length (CS) through the step-by-step traffic control speed, it is possible to reduce the congestion dispersion section to the upstream. Therefore, a strategy to control the passage speed control step by step in the section corresponding to the control section length from the bottleneck section to the upstream direction can be a practical application to lower the average passage speed of the upstream section of the bottleneck section.

<Description of Method>

A variable speed control method according to an embodiment of the present invention will be described with reference to the flowchart shown in FIG.

1. Receive road information <S501>

Receive road information such as road location information, road speed limit, traffic information, environmental information, and the like.

2. Calculate traffic control speed <S502>

When a bottleneck section in which a bottleneck is generated is detected through the road information received in step S501, an upstream part of the section in consideration of the usual capacity Qd, the free speed Uf, and the bottleneck capacity Qac in the section. Calculate the traffic control speed at. The usual capacity is traffic when no bottleneck occurs, and free speed means average passage speed or speed limit when no bottleneck occurs. In this step, the traffic control speed Uvsl is calculated to maintain the density Kd based on the inflow traffic flow rate (ingress traffic per hour), but the free speed Uf is lower than the minimum speed Ud of the bottleneck section. Calculate through the equation.

 Uvsl: traffic control speed

Qac: bottleneck capacity

Kd: density corresponding to inflow rate

Qd: usual capacity

Uf: free speed

Ud: Congestion rate without control

3. Calculate passage control time S503 >

Traffic control time (Tc) is the time from the start of traffic control due to the congestion shock wave caused by the bottleneck, from the bottleneck to the bottleneck to the end of the bottleneck. Is calculated by

Tc: traffic control time

Ts: Start of traffic control

Te: End of traffic control

Xqueue: queue length

Wc: Bottleneck Shockwaves

Tb: Bottleneck

Ta: the beginning of the bottleneck

W1: congestion shock wave due to bottleneck

4. Calculate the control section length <S504>

Control section to apply the traffic control speed based on the traffic control speed calculated in step S503 in order to control the congestion propagation upstream for a predetermined unit time (pass control time) based on the traffic control speed calculated in step S503 The length CS is calculated by calculating the product of the traffic control speed and the traffic control time in the upstream portion.

The change of the congestion shock wave and the total retardation area when the variable speed control method is applied is shown in FIG. 3. In general, as the traffic control speed decreases, the average density of the upstream portion increases, so that the speed of the congestion shock wave is set to 0 to prevent the rapid increase of the congestion shock wave during control, but the traffic can be maximized in consideration of the reduced capacity. It is desirable to calculate the control speed. Therefore, it can be seen that when the velocity of the congestion shock wave is 0, the total retardation area decreases as compared with the conventional one.

5. Control to apply the traffic control speed to the corresponding section <S505>

It is controlled to apply the calculated traffic control speed to the section corresponding to the control section length calculated in step S504 in the upstream direction from the bottleneck section. For example, the traffic control speed may be displayed on a field facility such as an electric signboard installed on the road, or the traffic control speed may be provided to a personal terminal based on wireless communication so that the traffic control speed may be applied to the vehicle.

As described above, the present invention has an effect of preventing congestion from being weighted upstream of the bottleneck section after congestion has already occurred due to factors such as an accident. In particular, by minimizing the speed of the congestion shock wave, the unstable traffic flow can be converted into the stable traffic flow because the area of the congestion zone and the queue length are ultimately reduced to maximize the passing traffic. In addition, unlike the prior art, more accurate control is possible by considering not only how much the deceleration should occur when the bottleneck occurs, but also the control section and the control time that deceleration should be made.

On the other hand, the variable speed control method described above maintains the velocity Uvsl of the upstream portion by performing a predetermined time control at a single speed to prevent upstream propagation of congestion, and congestion with a density of up to Kd '(see FIG. 3). To spatially disperse. The method has a disadvantage in that when the bottleneck time becomes long, the control section distance CS is rapidly increased in order to cancel the congestion shock wave. Accordingly, the present invention considers a method of controlling the congestion shock wave by applying the traffic control speed in multiple stages to the control target traffic volume Qd-Qac during the same unit time Tc.

6. Calculate passage control time <S506>

Since the step process is the same as step S503 described above, a description thereof will be omitted.

7. Dividing traffic control time into several sections <S507>

The passage control time calculated in step S506 is divided into two or more sections.

8. Calculate traffic control speed for each step <S508>

Different traffic control speeds are calculated for the divided sections in step S507. The traffic control speed for each step is calculated by considering the traffic control speed (Un-1), capacity (Qac) and usual capacity (Qd) of the previous step based on each step, and is calculated by the following equation.

 Un: Traffic control speed of n steps

Qac: bottleneck capacity

Qd: usual capacity

Un-1: Traffic control speed of previous step of n steps

Uf: free speed

Ud: Congestion rate without control

9. Calculate control section length <S509>

The control section length CS to which the traffic control speed is to be applied is calculated based on the traffic control speed calculated in step S508. The control section length CS is calculated by multiplying the traffic control speed and the traffic control time in the upstream part. Calculate by

CS: control section length

Tc: traffic control time

Uf: free speed

Qac: bottleneck capacity

Qd: usual capacity

n: step

10. Control to apply the passage control speed for each section <S510>

The control section length calculated in step S509 is controlled to apply the traffic control speed for each step calculated in step S508.

This results in a lower final traffic control speed than the initial traffic control speed and a relatively higher control density than when the traffic control speed is applied at a single speed as described above (see FIG. 3). do. However, it is possible to shorten the overall control section length through the passage control speed for each step, thereby reducing the congestion distribution section to the upstream part. Therefore, a strategy to control the passage speed control step by step in the section corresponding to the control section length from the bottleneck section to the upstream direction can be a practical application to lower the average passage speed of the upstream section of the bottleneck section.

Hereinafter, various cases will be compared and analyzed in order to find out the efficiency through the passage control speed in stages.

The basic traffic characteristics conditions for the experiment were applied to the traffic volume-density relationship, capacity and critical density value. It is assumed that the vehicle driving on the target axis is 100% passenger car, and the compliance to the variable speed control is also 100% to clearly confirm the analysis effect. The analysis site is analyzed based on the ideal type of virtual continuous flow road. The road to be analyzed consists of a total of 11km of one-way lanes and assumes the basic section of the highway without entry and exit. The scenario for effect analysis evaluates the applicability of the model in case of congestion according to traffic conditions, and suggests an effect measure by dividing it into indicators related to congestion improvement and indicators to stabilize traffic flow.

Analysis data overview division Condition Geometry -11km two way highway
-Basic section of the ship without entry / exit Traffic condition -Road capacity: 4,400 vehicles / hour
-Traffic entering: 3,000 vehicles / hour Traffic situation -Bottleneck: 1km downstream
-Analysis section: 10km upstream of the bottleneck
-Bottleneck time: 5 minutes after analysis start
Bottleneck duration: 10 minutes

As a variable speed control strategy for analysis, the control speed is suggested based on the inflow traffic and the reduced bottleneck capacity, but the control of three scenarios is performed according to the control speed level to clearly confirm the agreement with the result of the graphical solution. Speed and control time were determined. Here, it is assumed that if the control information is provided using a personal terminal based on wireless communication, more detailed control can be performed based on the control target point regardless of the installation location of the on-site facilities. As a tool for effect analysis, we applied VISSIM, a microscopic simulation model. In the scenarios 1 and 2 of the three scenarios, the control was performed for 10 minutes after the bottleneck occurred 30 seconds for the 10km upstream of the bottleneck section.

Analysis scenario division Control strategy Scenario 1 -Control speed: 110km / h
-Set the control target traffic to be larger than the reduced downstream capacity
10 minutes for upstream 10km Scenario 2 -Control speed: 70km / h
-Set the control target traffic smaller than the reduced downstream capacity
10 minutes for upstream 10km Scenario 3 -Speed control step by step (90km / h-70km / h-50km / b)
-Set the control target traffic according to the reduced downstream capacity, but adjust the control speed in two steps
-10 minutes control for upstream 4km

As a first look at the congestion improvement items, the congestion improvement analysis shows that the scenario elimination time is the same as in the case of uncontrolled scenario in scenario 1 where the control speed is 110 km. In scenarios 2 and 3, the reduction in queue length was found to have the greatest reduction in light queue resolution time. In both scenarios, the queue length was less than l00m, the minimum unit distance, and the queue resolution time was reduced by up to 95%. However, in case of scenario 3 controlled at 70km / h, the amount of traffic passing through the bottleneck was smaller than that of uncontrolled, and TTI, which is an indicator of the change in travel time compared to the condition of normal traffic, was also compared to that of no control. It was high.

This is explained based on the traffic volume-density relationship. According to the effect of the variable speed control demonstrated above, if the speed is reduced based on a specific time period, the traffic of the entrance is temporarily lowered at the same density. In the case of scenario 2, the control speed of 70km / h resulted in the temporary decrease of the traffic flow rate of 3,000 vehicles / hour to 1,750 vehicles / hour, which is lower than the bottleneck section capacity of 2,200 vehicles / hour. Accordingly, the amount of traffic passing through was calculated to be smaller than that of uncontrolled traffic. Therefore, TTI based on the total traffic volume was also higher than that of uncontrolled traffic.

According to the speed distribution of each scenario, the congestion section occupied about 4% of the total section in case of no control, but it decreased from 3% in scenario l to less than 0.5% in scenario 2 and 3 according to the control execution strategy. Analyzes (see FIG. 7). In the case of Scenario 3, the average speed of 70km / h or more was reduced compared to MJC because the speed was distributed as a result of applying the speed control criteria to 90-70-50km / h step by step, instead of 50 ~ 70km / h. The proportion of intervals increased from 0.38% to 12% when uncontrolled.

The traffic flow stabilization index was analyzed for the density and speed deviation calculated based on the unit interval.

Comparative analysis of control results between scenarios scenario Congestion improvement Traffic flow stabilization Traffic passing through
(versus) Travel
Time Index Queue length
(km) Queue
Resolution time Bottleneck
Density dispersion Section speed
Standard Deviation Uncontrolled 366 1.07 0.9 4 minutes 30 seconds 15.11 4.50 Scenario 1 366 1.07 0.8 4 minutes 30 seconds 13.45 4.50 Scenario 2 315 1.11 0.1 21 seconds 6.67 3.61 Scenario 3 366 1.07 0.1 9 seconds 7.48 2.40

As a result, it was analyzed that the standard deviation of speed and density of each section appeared to be lower when the speed was lowered and controlled, which could reduce the variation of the characteristics of traffic flow. Looking at the traffic volume-density relationship for each scenario, it can be seen that the variable speed control transitioned from the unstable traffic flow state to the stable traffic state due to the capacity reduction based on the critical density.

In the present invention, a stepwise variable speed control technique is applied as a technique for stabilizing traffic flow when congestion occurs for vehicles entering the continuous flow line. In addition, according to the case analysis, the congestion degree upstream of the bottleneck can be improved without increasing the total travel time according to the adequacy of the establishment of the variable speed control strategy, and it is analyzed that it is effective in stabilizing traffic flow. As a model that calculates the control speed based on the speed control principle has been proposed, the variable speed control can be simply reduced by the speed of the congestion section (speed harmonization) or as a queue warning function for safe entry in the event of a queue ahead. It is expected to be able to secure applicability in terms of congestion management different from the one applied.

The variable speed control method according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed by 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 those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

100: variable speed control system
101: road information receiving unit 102: traffic control speed calculation unit
103: control section length calculation unit 104: traffic control speed control unit
105: section divider

Claims (15)

A road information receiver for receiving road information;
When the bottleneck section where the bottleneck phenomenon is detected through the received road information is detected, the upstream portion of the bottleneck section considering the usual capacity (Qd), free speed (Uf) and bottleneck capacity (Qac) in the bottleneck section A traffic control speed calculating unit for calculating a traffic control speed in the vehicle;
A control section length calculator configured to calculate a control section length to which the traffic control speed is applied based on the traffic control speed; And
And a traffic control speed control unit controlling to apply the calculated traffic control speed to a section corresponding to the calculated control section length in an upstream direction from the bottleneck section.
The passage control speed is calculated by the following equation
Variable speed control system, characterized in that.
(Equation)

Uvsl: traffic control speed
Qac: bottleneck capacity
Qd: usual capacity
Uf: free speed delete The method of claim 1,
The control section length calculating unit calculates the control section length by the product of the calculated traffic control speed and traffic control time,
At this time, the passage control time is from the time when the traffic control is started due to the congestion shock wave caused by the bottleneck, from the bottleneck to the bottleneck of the bottleneck after the bottleneck clearing shock shock wave to the end of all bottlenecks upstream
Variable speed control system, characterized in that. The method of claim 3,
The passage control time is calculated by the following equation
Variable speed control system, characterized in that.
(Equation)

Tc: traffic control time
Xqueue: queue length
W1: congestion shock wave due to bottleneck
Wc: Bottleneck Shockwaves
Tb: Bottleneck
Ta: the beginning of the bottleneck The method of claim 3,
A section dividing unit dividing the passage control time into two or more sections; Further comprising:
The passage control speed calculation unit,
Calculate different traffic control speeds in the divided sections,
The traffic control speed control unit,
Control to apply the calculated traffic control speed for each step to the calculated control section length
Variable speed control system, characterized in that. 6. The method of claim 5,
The traffic control speed for each step is calculated by considering the traffic control speed (Un-1) of the previous step, the capacity (Qac) and the usual capacity (Qd) when the bottleneck occurs, based on each step,
Calculated by the equation
Variable speed control system, characterized in that.
(Equation)

Un: Traffic control speed of n steps
Qac: bottleneck capacity
Qd: usual capacity
Un-1: Traffic control speed of previous step of n steps 6. The method of claim 5,
The control section length calculating unit calculates the control section length by the following equation.
Variable speed control system, characterized in that.
(Equation)

CS: control section length
Tc: traffic control time
Uf: free speed
Qac: bottleneck capacity
Qd: usual capacity
n: step Receiving road information;
When the bottleneck section where the bottleneck phenomenon is detected through the received road information is detected, the traffic in the upstream portion of the section in consideration of the usual capacity (Qd), the free speed (Uf) and the capacity (Qac) when the bottleneck occurs in the section Calculating a control speed;
Calculating a control section length to which the traffic control speed is to be applied based on the traffic control speed; And
And controlling to apply the calculated traffic control speed to a section corresponding to the calculated control section length in an upstream direction from the bottleneck section.
The passage control speed is calculated by the following equation
Variable speed control method, characterized in that.
(Equation)

Uvsl: traffic control speed
Qac: bottleneck capacity
Qd: usual capacity
Uf: free speed delete 9. The method of claim 8,
In calculating the control section length, the control section length is calculated by multiplying the calculated traffic control speed and traffic control time.
At this time, the passage control time is from the time when the traffic control is started due to the congestion shock wave caused by the bottleneck, from the bottleneck to the bottleneck of the bottleneck after the bottleneck clearing shock shock wave to the end of all bottlenecks upstream
Variable speed control method, characterized in that. 11. The method of claim 10,
The passage control time is calculated by the following equation
Variable speed control method, characterized in that.
(Equation)

Tc: traffic control time
Xqueue: queue length
W1: congestion shock wave due to bottleneck
Wc: Bottleneck Shockwaves
Tb: Bottleneck
Ta: the beginning of the bottleneck 11. The method of claim 10,
Dividing the passage control time into two or more sections;
Calculating different traffic control speeds in the divided sections; And
Controlling to apply the calculated traffic control speed for each step to the calculated control section length;
Variable speed control method characterized in that it further comprises. The method of claim 12,
The traffic control speed for each step is calculated by considering the traffic control speed (Un-1) of the previous step, the capacity (Qac) when the bottleneck occurs, and the capacity (Qd) in the section based on each step.
Calculated by the equation
Variable speed control method, characterized in that.
(Equation)

Un: Traffic control speed of n steps
Qac: bottleneck capacity
Qd: usual capacity
Un-1: Traffic control speed of previous step of n steps The method of claim 12,
In the calculating of the control section length, the control section length is calculated by the following equation.
Variable speed control method, characterized in that.
(Equation)

CS: control section length
Tc: traffic control time
Uf: free speed
Qac: bottleneck capacity
Qd: usual capacity
n: step A computer-readable recording medium in which a program for executing the method of any one of claims 8 and 10 to 14 is recorded.

Images