CN113936480A

CN113936480A - Traffic signal control method and equipment

Info

Publication number: CN113936480A
Application number: CN202111330989.9A
Authority: CN
Inventors: 王玉波; 王雷雷; 李贺
Original assignee: Hisense TransTech Co Ltd
Current assignee: Hisense TransTech Co Ltd
Priority date: 2021-11-11
Filing date: 2021-11-11
Publication date: 2022-01-14
Anticipated expiration: 2041-11-11
Also published as: CN113936480B

Abstract

The invention discloses a control method and a device of traffic signals, wherein a processor in the device is configured to execute the following steps: determining a road section to be regulated and an intersection to be regulated according to the vehicle space density and the vehicle average speed in the area to be recognized of each road section; adjusting the green light signal of the control direction to be adjusted according to the residual green light duration of the control direction to be adjusted of the road section to be adjusted at the current moment; determining the control interception time length; determining a target association control intersection of the intersection to be adjusted based on a traffic flow ratio principle; determining a green light time length adjusting proportion of the intersection to be adjusted and green light time length adjusting proportions of all upstream target control intersections in the target associated intersections according to the control closure time length, and determining a green light time length adjusting proportion of all downstream target control intersections in the target associated control intersections according to the total control quantity of the road section to be adjusted; and adjusting the green light time length of the corresponding intersection according to the green light time length adjusting proportion. The timeliness of intersection overflow control is improved, and congestion transfer is prevented.

Description

Traffic signal control method and equipment

Technical Field

The invention relates to the field of control of intelligent traffic signals, in particular to a traffic signal control method and traffic signal control equipment.

Background

As traffic becomes more developed, the number of private cars becomes greater, with road congestion caused by short-term aggregation. At the intersection, the driving direction of each vehicle may be changed or changed, so that the intersection is more likely to be congested, and the vehicle congestion at the intersection is called intersection overflow.

In the related art, in the control of the intersection overflow, post-event control is generally adopted, that is, after the overflow occurs, the control is performed on the overflowing road section and the intersection. This results in the intersection having been deadlocked when the overflow is determined. In addition, congestion transfer situations may also occur, leading to congestion in other links.

Disclosure of Invention

The invention provides a traffic signal control method and equipment, which are used for improving timeliness of intersection overflow control and effectively preventing congestion transfer through control on an associated intersection.

According to a first aspect of the exemplary embodiments, there is provided a method of controlling a traffic signal, the method comprising: .

In the area to be identified of the road section, determining the road section to be adjusted and the intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed; the road section to be adjusted is a road section which needs to be subjected to overflow adjustment; the intersection to be adjusted is the first control intersection in the upstream direction of the road section to be adjusted;

adjusting the green light signal of the control direction to be adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold; determining the control interception time length of the control direction to be adjusted in the adjusting process;

determining a target association control intersection of the intersection to be adjusted based on the proportion of the traffic flow passing through the road section to be adjusted from each association control intersection in the total traffic flow of the road section to be adjusted in a set time period; the target association control intersection comprises an upstream target control intersection and a downstream target control intersection;

determining a green light time length adjusting proportion of the intersection to be adjusted and green light time length adjusting proportions of all upstream target control intersections in the target associated intersections according to the control interception time length, and determining a green light time length adjusting proportion of all downstream target control intersections in the target associated control intersections according to the total control quantity of the road section to be adjusted; the total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in the set time period;

and adjusting the green light time length of the corresponding intersection according to the green light time length adjusting proportion.

In the embodiment of the application, a region to be identified is defined, a road section to be adjusted and an intersection to be adjusted are accurately identified according to the periodically detected vehicle space density and the vehicle average speed, a green light signal of a control direction to be adjusted is adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold, the intersection to be adjusted is immediately responded, and the method is high in precision and high in timeliness; meanwhile, in order to prevent congestion transfer, a plurality of target association control intersections are linked, the green light adjusting time length of each upstream target control intersection and each downstream target control intersection is respectively determined, and the green light time length of the corresponding intersection is adjusted by applying the green light time length adjusting proportion. The crossing overflow and the congestion transfer are effectively prevented, and the traffic congestion is relieved.

In some exemplary embodiments, the determining, in the area to be identified in the road segment, a road segment to be adjusted and an intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed includes:

in the area to be identified of the road section, determining the space density and the average speed of vehicles which are detected periodically;

and if the space density of the vehicles in the continuous first preset duration range is greater than a first preset density threshold value, and the average speed of the vehicles is less than a first average speed threshold value, determining that the road section to which the area to be identified belongs is a road section to be adjusted, and determining that the crossing of the road section to be adjusted in the coming direction is the crossing to be adjusted.

According to the embodiment, the space density of the vehicles and the average speed of the vehicles in the road section are comprehensively considered, the road section to be adjusted can be accurately identified, and further error control caused by error identification can be prevented.

In some exemplary embodiments, the determining a control interception time length of the to-be-adjusted control direction according to a remaining green light time length of the to-be-adjusted control direction of the to-be-adjusted road section at the current time, and applying the control interception time length to adjust the green light time length of the to-be-adjusted control direction includes:

according to the phase sequence of the intersection to be adjusted, when the green light duration in the previous direction of the control direction to be adjusted is finished, determining the remaining green light duration in the control direction to be adjusted;

if the remaining green light duration is greater than a preset duration threshold, switching the green light signal of the control direction to be adjusted into a red light signal;

if the road section to be adjusted meets the dissipation condition and the residual green light time of the control direction to be adjusted is longer than the preset green light time, switching the red light signal of the control direction to be adjusted into a green light signal;

determining the control interception time length of the control direction to be adjusted in the adjusting process;

wherein the dissipation conditions include:

and the space density of the vehicle in the continuous second preset time range is smaller than a second preset density threshold value, and the average speed of the vehicle is larger than a second average speed threshold value.

In the embodiment, the signal adjusting strategy of the road section to be adjusted is determined by comparing the relation between the residual green light time length of the control direction to be adjusted of the intersection to be adjusted and the preset time length threshold value; and after the dissipation condition is met and the residual green light duration of the control direction to be adjusted is longer than the preset green light duration, switching the red light signal of the control direction to be adjusted into a green light signal. The control strategy can accurately adjust the intersection to be adjusted.

In some exemplary embodiments, in the association control intersection of the intersection to be adjusted, determining the target association control intersection of the intersection to be adjusted based on a proportion of traffic flow passing through the road section to be adjusted from each association control intersection to a total traffic flow of the road section to be adjusted within a set time period includes:

determining the traffic flow of each associated control intersection entering and exiting the road section to be adjusted in the associated control intersections of the intersections to be adjusted within the set time period;

determining the proportion of the traffic flow of each associated control intersection to the total traffic flow of the road section to be adjusted in the set time period;

and determining the associated control intersection with the proportion larger than a preset proportion threshold value as a target associated control intersection.

In the above embodiment, because the independent control of the intersection to be adjusted may cause congestion at the upstream and downstream control intersections, the intersection affected by the control of the intersection to be adjusted is found as the target associated control intersection according to the relationship between the traffic flow of the intersection and the total traffic flow of the road segment to be adjusted, and then the adjustment strategy is specified for each target associated control intersection.

In some exemplary embodiments, the determining the green light time length adjustment ratio of the intersection to be adjusted and the green light time length adjustment ratio of each upstream target control intersection in the target-related intersections according to the control cut-off time length includes:

determining the green light time length adjusting proportion of the intersection to be adjusted according to the control cut-off time length and a preset green signal ratio;

and determining the green light time length adjusting proportion of each upstream target control intersection according to the green light time length adjusting proportion of the intersection to be adjusted and the cascade relation between each upstream target control intersection and the intersection to be adjusted.

In the embodiment, the cascade relation between the upstream target control intersection and the intersection to be adjusted is considered, and the green light time length adjusting proportion of the intersection to be adjusted and each upstream target control intersection is determined, so that the green light time length adjusting proportion of each upstream target control intersection is applied to adjust the corresponding intersection, and the congestion of each upstream target control intersection can be effectively prevented.

In some exemplary embodiments, the determining, according to the total control quantity of the road segment to be adjusted, a green light time length adjustment ratio of each downstream target control intersection in the target associated control intersections includes:

determining the regulating flow distributed to each downstream target control intersection according to the total control quantity of the road section to be regulated and the traffic flow distribution relation between the upstream target control intersection and the downstream target control intersection;

determining the green light time length adjusting proportion of the downstream first-level target control intersection according to the adjusting flow distributed to the downstream target control intersection and the vehicle flow of the downstream first-level target control intersection;

and determining the green light time length adjusting proportion of each downstream target control intersection except the downstream first-level target according to the green light time length adjusting proportion of the downstream first-level target control intersection and the cascade relation between each downstream target control intersection and the downstream first-level target control intersection.

In the embodiment, the cascade relation between each downstream other-level target control intersection and the downstream one-level target control intersection is considered, and the green light time length adjusting proportion of each downstream target control intersection is determined, so that the green light time length adjusting proportion of each downstream target control intersection is applied to adjust the corresponding intersection, and the congestion of each downstream target control intersection can be effectively prevented.

In some exemplary embodiments, before applying each of the green light time period adjustment ratios to adjust the green light time period of the corresponding intersection, the method further comprises:

if a first green light time length adjusting proportion larger than the maximum value in the adjusting proportion threshold value range exists, updating the first green light time length adjusting proportion by applying the maximum value;

and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold value range exists, updating the second green light time length adjusting proportion by applying the minimum value.

According to a second aspect of the exemplary embodiments, there is provided a control device for traffic signals, the control device comprising a processor;

the processor is configured to perform:

in the area to be identified of each road section, determining the road section to be adjusted and the intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed; the road section to be adjusted is a road section which needs to be subjected to overflow adjustment; the intersection to be adjusted is the first control intersection in the upstream direction of the road section to be adjusted;

In some exemplary embodiments, the processor is configured to perform:

wherein the dissipation conditions include:

In some exemplary embodiments, the processor is configured to perform:

In some exemplary embodiments, the processor is further configured to perform:

before each green light time length adjusting proportion is applied to adjust the green light time length of the corresponding intersection, if a first green light time length adjusting proportion larger than the maximum value in the adjusting proportion threshold value range exists, the maximum value is applied to update the first green light time length adjusting proportion; and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold value range exists, updating the second green light time length adjusting proportion by applying the minimum value.

According to a third aspect of the exemplary embodiments, there is provided a control apparatus of a traffic signal, the apparatus comprising:

the first determining module is used for determining a road section to be adjusted and an intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed in the area to be identified of the road section; the road section to be adjusted is a road section which needs to be subjected to overflow adjustment; the intersection to be adjusted is the first control intersection in the upstream direction of the road section to be adjusted;

the first adjusting module is used for adjusting the green light signal of the control direction to be adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold; determining the control interception time length of the control direction to be adjusted in the adjusting process;

the second determining module is used for determining a target association control intersection of the intersection to be adjusted based on the proportion of the traffic flow passing through the road section to be adjusted from each association control intersection in the total traffic flow of the road section to be adjusted in a set time period; the target association control intersection comprises an upstream target control intersection and a downstream target control intersection;

the third determining module is used for determining the green light time length adjusting proportion of the intersection to be adjusted and the green light time length adjusting proportion of each upstream target control intersection in the target associated intersections according to the control interception time length, and determining the green light time length adjusting proportion of each downstream target control intersection in the target associated control intersections according to the total control quantity of the road section to be adjusted; the total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in the set time period;

and the second adjusting module is used for adjusting the green light time length of the corresponding intersection according to the green light time length adjusting proportion.

In some exemplary embodiments, the first determining module is specifically configured to:

In some exemplary embodiments, the first adjusting module is specifically configured to:

wherein the dissipation conditions include:

In some exemplary embodiments, the second determining module is specifically configured to:

In some exemplary embodiments, the third determining module is specifically configured to:

In some exemplary embodiments, the method further includes updating, before applying each of the green light time period adjustment ratios to adjust the green light time period of the corresponding intersection, a first green light time period adjustment ratio that is greater than a maximum value within the adjustment ratio threshold range if there is a first green light time period adjustment ratio, and updating, by applying the maximum value, the first green light time period adjustment ratio; and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold value range exists, updating the second green light time length adjusting proportion by applying the minimum value.

According to a fourth aspect of the exemplary embodiments, there is provided a computer storage medium having stored therein computer program instructions which, when run on a computer, cause the computer to execute the method of controlling a traffic signal according to the first aspect.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic view illustrating an application scenario of a control method for a traffic signal according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a method for controlling a traffic signal according to an embodiment of the present invention;

fig. 3 is a flowchart illustrating a control method for traffic signals of a road section to be adjusted according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating coordinated control of traffic signals provided by an embodiment of the invention;

fig. 5 is a flowchart illustrating a control method for traffic signals according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram illustrating a control device for traffic signals according to an embodiment of the present invention.

Detailed Description

The technical solution in the embodiments of the present application will be described in detail and removed with reference to the accompanying drawings. In the description of the embodiments herein, "/" means "or" unless otherwise specified, for example, a/B may mean a or B; "and/or" in the text is only an association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B may mean: three cases of a alone, a and B both, and B alone exist, and in addition, "a plurality" means two or more than two in the description of the embodiments of the present application.

In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as implying or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of embodiments of the application, unless stated otherwise, "plurality" means two or more.

With the increasingly developed traffic, the number of private cars is increasing. With consequent congestion of the road. At the intersection, the driving direction of each vehicle may be changed or changed, so that the intersection is more likely to be congested, and the vehicle congestion at the intersection is called intersection overflow.

In the control of intersection overflow, video, coil, geomagnetic and other devices are mainly used at present to sense the position of each vehicle, and intersection signals are controlled incorrectly and have poor effect and cannot be applied continuously due to false triggering or serious false recognition; and the timeliness of overflow identification cannot be guaranteed by utilizing the internet or vehicle track identification, so that the intersection is deadlocked after the overflow is determined. Therefore, the control of intersection overflow in the prior art is low in precision and poor in timeliness.

Therefore, the embodiment of the application provides a control method of traffic signals, which comprises the steps of judging a road section to be regulated and an intersection to be regulated according to vehicle space density and vehicle average speed, regulating green light signals of a control direction to be regulated according to the relation between the residual green light time of the control direction to be regulated of the road section to be regulated at the current moment and a preset time threshold, and confirming the control interception time in the process. Because the road section to be adjusted is adjusted to cause congestion of an upstream road section or a downstream road section, target association control intersections (an upstream target control intersection and a downstream target control intersection) of the road section to be adjusted are determined, the green light time length adjusting proportion of each target association control intersection is determined, and the green light time length of the corresponding road section is adjusted by applying each green light time length adjusting proportion. Therefore, the control of the road section to be adjusted is realized, the related intersection is controlled, and the timeliness of the intersection overflow control is improved.

After introducing the design concept of the embodiment of the present application, some simple descriptions are provided below for application scenarios to which the technical solution of the embodiment of the present application can be applied, and it should be noted that the application scenarios described below are only used for describing the embodiment of the present application and are not limited. In specific implementation, the technical scheme provided by the embodiment of the application can be flexibly applied according to actual needs.

Referring to fig. 1, an application scenario diagram of a traffic signal control method is shown, in which a radar detector or other video capture devices are installed on a signal light pole of an intersection, a fixed detection area within a range of 50 meters is defined from a stop line to a direction of an exit of the intersection by 30 meters, in order to prevent false detection caused by roadside parking of the rightmost lane, the detection area may be close to an inner lane, and the rightmost lane is not generally used as an overflow recognition area to eliminate interference of the rightmost lane.

To further illustrate the technical solutions provided by the embodiments of the present application, the following detailed description is made with reference to the accompanying drawings and the detailed description. Although the embodiments of the present application provide method steps as shown in the following embodiments or figures, more or fewer steps may be included in the method based on conventional or non-inventive efforts. In steps where no necessary causal relationship exists logically, the order of execution of the steps is not limited to that provided by the embodiments of the present application.

The following describes, with reference to an application scenario shown in fig. 1, a flowchart of a traffic signal control method shown in fig. 2, a technical solution provided in an embodiment of the present application.

S201, determining a road section to be regulated and an intersection to be regulated according to the periodically detected vehicle space density and the vehicle average speed in an area to be identified of the road section; the road section to be adjusted is a road section which needs to be subjected to overflow adjustment; the intersection to be adjusted is the first control intersection in the upstream direction of the road section to be adjusted.

S202, adjusting a green light signal of the control direction to be adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold; and determining the control interception time length of the control direction to be adjusted in the adjusting process.

S203, in the associated control intersections of the intersections to be adjusted, determining the target associated control intersections of the intersections to be adjusted based on the proportion of the traffic flow passing through the road sections to be adjusted from each associated control intersection in the set time period to the total traffic flow of the road sections to be adjusted; the target association control intersection comprises an upstream target control intersection and a downstream target control intersection.

S204, determining a green light time length adjusting proportion of the intersection to be adjusted and green light time length adjusting proportions of all upstream target control intersections in the target associated intersections according to the control cut-off time length, and determining a green light time length adjusting proportion of all downstream target control intersections in the target associated control intersections according to the total control quantity of the road section to be adjusted; the total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in the set time period.

S205, the green light time length of the corresponding intersection is adjusted by applying the green light time length adjusting proportion.

In the embodiment of the application, a region to be identified is defined, a road section to be adjusted and an intersection to be adjusted are accurately identified according to the periodically detected vehicle space density and the vehicle average speed, a green light signal of a control direction to be adjusted is adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold, the intersection to be adjusted is immediately responded, and the accuracy and the timeliness are high; meanwhile, in order to prevent congestion transfer, a plurality of target association control intersections are linked, the green light adjusting time of each upstream target control intersection and each downstream target control intersection are respectively determined, and the green light time of the corresponding intersection is adjusted by applying each green light time adjusting proportion. The crossing overflow and the congestion transfer are effectively prevented, and the traffic congestion is relieved.

Referring to S201, a link is taken as an example, and whether the link is a link to be adjusted is determined as follows. When a certain road section is a road section to be adjusted, the first crossing at the upstream of the certain road section is the crossing to be adjusted. For example, in order to improve the identification accuracy, the area to be identified of the road segment may be determined as shown in fig. 1, so that, for the area to be identified of the current road segment, the vehicle space density and the vehicle average speed are periodically detected, and then it is determined whether the road segment is the road segment to be adjusted and the intersection to be adjusted according to the detected vehicle space density and the vehicle average speed.

The road section to be adjusted can be determined in the following way:

in an area to be identified of a road section, determining the space density and the average speed of vehicles which are detected periodically; and if the space density of the vehicles in the continuous first preset duration range is greater than a first preset density threshold value and the average speed of the vehicles is less than a first average speed threshold value, determining that the road section to which the area to be identified belongs is the road section to be adjusted and the crossing of the coming direction of the road section to be adjusted is the crossing to be adjusted.

In one specific example, the spatial density ρ of the vehicle in the lane i per second of the region to be identified is first determined_iAverage vehicle speed of lane i

Thus, a space density of the vehicle is obtained

Wherein N is the number of lanes contained in the area to be identified,

the lane i is provided with Ji vehicles L_jiThe length of the jth vehicle on the lane i and the average distance delta between the queued vehicles can be 1.8 meters. Average speed of vehicles in the area to be identified

Wherein

v_jIs the speed of the jth vehicle on lane i.

In the process of judging the road section to be adjusted, a first preset density threshold value rho₁And a first average speed threshold v₁Determined as follows. Based on a large amount of sample data observation, obtainingThe number of vehicles on a 50 meter lane, vehicle space density threshold and traffic conditions are related as in table 1:

TABLE 150 m number of vehicles on a lane, vehicle space density threshold, and traffic status

In this manner, a first preset density threshold ρ may be determined₁The critical value of the intermediate state and the congestion state is 0.5; first average speed threshold v₁The determination process is as follows:

based on a large amount of sample data analysis, the approximate rate between the minimum distance and the speed of the vehicle is in accordance with the following formula:

wherein v is_xAs the average speed of the vehicle, d_min＝f(v_x) The corresponding minimum vehicle distance is obtained. According to table 1, when 6 vehicles on a 50-meter lane start to be congested, if the average occupied space of the vehicles in the congested state is 50 m/6-8.33 m, the standard occupied space of a single vehicle is 4.8+ 1.8-6.6 m, and the minimum vehicle distance of the vehicles is 8.33-6.6 m-1.73 m, the above formula is substituted, and a congestion average speed threshold (a first average speed threshold) v is obtained₁It was 3.46 m/s.

Referring to S202, when it is determined that the road segment is the road segment to be adjusted, an adjustment policy, such as how to adjust the green light duration and the red light duration of the control direction to be adjusted, needs to be specified for the road segment.

Exemplarily, according to the phase sequence of the intersection to be adjusted, when the green light duration of the previous direction of the control direction to be adjusted is ended, determining the remaining green light duration of the control direction to be adjusted; if the remaining green light duration is greater than a preset duration threshold, switching the green light signal of the control direction to be adjusted into a red light signal; and if the road section to be adjusted meets the dissipation condition and the residual green light time of the control direction to be adjusted is longer than the preset green light time, switching the red light signal of the control direction to be adjusted into a green light signal.

Taking the intersection with the cars turning east as an example, the phases include west turning east, north turning left turning east and south turning right turning east, and the phase sequence refers to the sequence of the phases determined according to factors such as historical road conditions. Therefore, the order of the respective control directions is the order of the phases.

Thus, in the process of adjusting the intersection to be adjusted, according to the phase sequence of the intersection to be adjusted, when the green light duration in the previous direction (north left turn to east) of the control direction to be adjusted (for example, west to east) is ended, it indicates that there is no vehicle turning left to east in the north at this time, and the remaining green light duration in the west to east is determined. If the remaining green light duration is greater than a preset duration threshold (for example, 5 seconds), switching the green light signal of the control direction to be adjusted to red light information, for example, if the remaining green light duration is greater than 5 seconds, indicating that enough time is available to intercept the upstream vehicle to relieve the congestion condition at the current intersection; the remaining green light time is less than 5 seconds, which indicates that the upstream vehicle cannot be stopped at the moment, and the current control direction to be adjusted continues to be green until the end.

After the overflow condition is responded, if the road section to be adjusted meets the dissipation condition and the remaining green light time length of the control direction to be adjusted is longer than the preset green light time length (such as the minimum time for ensuring the safe street crossing of pedestrians), the overflow condition is indicated to be relieved at the moment, and the red light signal of the control direction to be adjusted is switched into the green light signal, so that the upstream coming vehicle normally passes.

In one particular example, the dissipation condition is determined by: and the space density of the vehicle in the continuous second preset time range is smaller than a second preset density threshold value, and the average speed of the vehicle is larger than a second average speed threshold value.

Referring to table 1, the second preset duration range may be 10 seconds, and the second preset density threshold ρ₂The critical value of the clear state and the intermediate state is taken to be 0.3. Second average speed threshold v₂Determined according to the relation between the traffic flow speed and the space density,

wherein v is_freeFor a free flow velocity of 50km/h, p_jamFor congestion density, take ρ₁. Example is v₂＝50*(1-0.3/0.5)＝20km/h。

As described above, after determining the strategy for performing one-time adjustment on the intersection to be adjusted, the control interception time length of the control direction to be adjusted corresponding to the adjustment process can be determined, where the control interception time length is the total red light time of the control direction to be adjusted in the control process.

Next, a flow chart is used to describe the control strategy of the intersection to be adjusted, see fig. 3.

And S301, starting an overflow control function.

And S302, determining that the prior control direction of the current control direction is released.

And S303, judging whether the current control direction needs to be adjusted, if so, executing S304, and otherwise, executing S305.

S304, judging whether the remaining green light time in the current control direction is larger than a preset time threshold, if so, executing S306, and if not, executing S305.

Wherein the preset time threshold is, for example, 5 seconds.

And S305, releasing the green light in the current control direction.

And S306, stopping the green light in the current control direction and switching to the red light.

And S307, judging whether the current control direction meets the dissipation condition, if so, executing S308, and otherwise, executing S306.

And S308, judging whether the residual green light time length of the current control direction is greater than the preset green light time length or not, if so, executing S309, and otherwise, executing S306.

S309, the red light of the current control direction is stopped, the red light is switched to the green light, and the step returns to execute the step S305.

As above, is one overflow control process for the road section to be adjusted.

In step S203, since only the road section to be adjusted and the corresponding intersection to be adjusted are controlled, other intersections upstream and downstream may be affected, and therefore, in order to improve the timeliness of overflow adjustment, an adjustment policy is specified for the other intersections affected by the determination of the adjustment policy for the intersection to be adjusted. In this process, a control intersection associated with the intersection to be adjusted is first determined.

Specifically, in a set time period, determining the traffic flow of each associated control intersection entering and exiting a road section to be adjusted in the associated control intersections of the intersections to be adjusted; determining the proportion of the traffic flow of each associated control intersection to the total traffic flow of the road section to be adjusted in a set time period; and determining the association control intersection with the proportion larger than the preset proportion threshold value as the target association control intersection, namely, the association control intersection needing to be adjusted.

The set time period is, for example, 5 seconds, the associated control intersections of the intersections to be adjusted refer to the control intersections upstream and downstream, and the arrival path and the departure path of each vehicle can be determined according to the detected arrival data and the detected passing data of each intersection. Therefore, the traffic flow of the road section to be regulated which enters and exits from each associated intersection can be determined, and meanwhile, the total traffic flow of the road section to be regulated in the same time period can be determined, so that the proportion of the traffic flow of each intersection to the total traffic flow can be calculated, and the traffic flow with the proportion larger than a preset proportion threshold (such as 10%) is used as the target associated intersection of the associated control intersection, namely, the target associated control intersection is screened out from the associated control intersections. It should be noted that, in the screening process, when each control intersection is considered, the traffic flow corresponding to a certain control direction is considered, and therefore, the finally determined target-related control intersection implicitly includes the corresponding control direction.

And according to the upstream and downstream relation with the intersection to be regulated, the target association control intersection comprises an upstream target control intersection and a downstream target control intersection. In a specific example, fig. 4 shows a schematic diagram of linkage control of a traffic signal, and it can be seen that the determined target association control intersections include an upstream second-level target control intersection, a downstream first-level target control intersection, a downstream second-level target control intersection, and a downstream third-level target control intersection; the proportion of the traffic flow at each control junction to the traffic flow at the junction to be regulated is also shown in fig. 4. In addition, in an actual scenario, the intersection to be adjusted is generally referred to as an upstream primary target control intersection.

Referring to S204, next, the green light time length adjustment proportion of each upstream target control intersection and each downstream target control intersection is respectively determined.

Firstly, controlling intersections aiming at each upstream target.

A. And determining the green light time length adjusting proportion of the intersection to be adjusted according to the control cut-off time length and the preset green signal ratio.

In general, the intersection to be adjusted is also referred to as an upstream control intersection, and therefore, the green light time length adjustment ratio of the upstream control intersection is determined first. In a specific example, the control cut-off time length is the sum of the red light time lengths of the intersection control to be adjusted, and deltag_inUsing a predetermined split g₀And determining the green light time length adjusting proportion of the intersection to be adjusted. For example, the green light time length adjustment proportion of the intersection to be adjusted is delta lambda_1,in＝Δg_in/g₀. Because the current intersection is the intersection to be adjusted, the green light time length of the green light time length adjusting proportion is compressed, and the green light time length adjusting proportion can be the green light time length compressing proportion.

B. And determining the green light time length adjusting proportion of each upstream target control intersection according to the green light time length adjusting proportion of the intersection to be adjusted and the cascade relation between each upstream target control intersection and the intersection to be adjusted.

And for other upstream level target control intersections, determining the corresponding green light time length adjusting proportion according to the cascade relation between the intersections and the intersections to be adjusted. In a specific example, the farthest upstream target control intersection is set as S level, and in order to equalize the pressure shared by each road segment, the time compression ratio of the control direction of the S level upstream intersection is set as

For example, if the upstream target control intersection is level 3, the time compression ratio of the upstream second target control intersection is Δ λ_1,in*2/3。

And secondly, controlling the intersection aiming at each downstream target.

A. And determining the regulating flow distributed to each downstream target control intersection according to the total control quantity of the road section to be regulated and the traffic flow distribution relation between the upstream target control intersection and the downstream target control intersection.

The total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in the set time period.

Specifically, calculating the difference between the driving-in flow and the driving-out flow of the road section to be regulated:

ΔS_d＝S_in-S_out＝∑_f1∈inq_f1-∑_f2∈outq_f2；

in the formula: delta S_dRepresenting the deviation of the incoming and outgoing flow of the upstream and downstream intersections of the road section to be regulated;

S_in＝∑_f1∈inq_f1the sum of the flow rates of all driving directions of an upstream entrance of the road section to be regulated; f1 represents the driving direction of the road section to be adjusted;

S_out＝∑_f2∈inq_f2the sum of the flow rates of all the exit directions of the downstream exit of the road section to be regulated; f2 represents the driving direction of the road section to be adjusted;

q_f1＝∑_pq_f1the sum of the traffic collection data for the last 5 minute period of the direction f1 corresponding to the detector (e.g., radar, video capture device, etc.) p.

The vehicle parking (or leaving) consumption amount of the road section to be regulated is as follows:

in the formula: l is the length of the road section to be adjusted; w is the number of lanes of the road section to be adjusted; l₀The space occupied by the bicycle in the congestion state is 6.6 by default, the delta is the control intensity, and the default is 0.3.

Therefore, the total control quantity of the road section to be adjusted is:

ΔS＝ΔS_l+max (ΔS_d,0)

the upstream inlet is compression control, and the compression flow is as follows:

the downstream outlet is controlled by adding and releasing, and the added flow is as follows:

ΔS_out＝ΔS-ΔS_in。

B. controlling the flow Δ S allocated at the intersection based on the downstream target_outAnd the traffic flow of the downstream first-level target control intersection, and determining the green light time length adjusting proportion of the downstream first-level target control intersection.

In the formula: sigma_i∈1,outq_i,kRepresenting the sum of the flow corresponding to the control direction of the downstream first-level intersection; q. q.s_i,kIndicating the total flow of the lane for the control direction k.

C. And determining the green light time length adjusting proportion of each downstream target control intersection except the downstream first-level target according to the green light time length adjusting proportion of the downstream first-level target control intersection and the cascade relation between each downstream target control intersection and the downstream first-level target control intersection.

Setting the farthest downstream control intersection as the level X, and in order to equalize the pressure shared by each road section, therefore, the time increase ratio of the control direction of the level X downstream intersection is:

and S205, in the process, the green light time length adjusting proportion of the intersection to be adjusted, each upstream target control intersection and each downstream target control intersection is determined, so that the green light time length of the intersection corresponding to the corresponding green light time length adjusting proportion is used for adjusting. According to the actual scene, the green light time of each upstream target control intersection is compressed, and the green light time of each downstream target control intersection is increased.

In addition, in order to prevent excessive control or ineffective control, the intersection time adjustment ratio is limited in association with each object. Therefore, before the green light time length of the corresponding intersection is adjusted by applying each green light time length adjusting proportion, whether each green light time length adjusting proportion is in the adjusting proportion threshold range or not is determined, and if the green light time length adjusting proportion is not in the adjusting proportion threshold range, different strategies are applied for adjusting.

For example, if there is a first green light time period adjustment ratio larger than the maximum value within the adjustment ratio threshold range, the maximum value (for example, 30%) is applied to update the first green light time period adjustment ratio, and 30% is used as the first green light time period adjustment ratio; and if the second green light time length adjusting proportion smaller than the minimum value (5%) in the adjusting proportion threshold range exists, updating the second green light time length adjusting proportion by using the minimum value, and taking 5% as the second green light time length adjusting proportion.

In order to make the technical solution of the present application easier to understand, a complete flow chart is described below, referring to fig. 5.

S501, in the area to be identified of the road section, the space density of the vehicles and the average speed of the vehicles which are detected periodically are determined.

S502, if the space density of the vehicles in the continuous first preset duration range is larger than a first preset density threshold value, and the average speed of the vehicles is smaller than a first average speed threshold value, determining that the road section to which the area to be identified belongs is a road section to be adjusted, and determining that the intersection of the road section to be adjusted in the coming direction is the intersection to be adjusted.

S503, according to the phase sequence of the intersection to be adjusted, when the green light duration of the previous direction of the control direction to be adjusted is finished, determining the remaining green light duration of the control direction to be adjusted.

S504, if the remaining green light duration is larger than the preset duration threshold, switching the green light signal of the control direction to be adjusted into a red light signal.

And S505, if the road section to be adjusted meets the dissipation condition and the remaining green light time of the control direction to be adjusted is longer than the preset green light time, switching the red light signal of the control direction to be adjusted into a green light signal.

And S506, determining the control interception time length of the control direction to be adjusted in the adjusting process.

Wherein the dissipation conditions include: and the space density of the vehicle in the continuous second preset time range is smaller than a second preset density threshold value, and the average speed of the vehicle is larger than a second average speed threshold value.

And S507, determining the traffic flow of each associated control intersection entering and exiting the road section to be regulated in the associated control intersections of the intersections to be regulated within a set time period.

And S508, determining the proportion of the traffic flow of each associated control intersection to the total traffic flow of the road section to be regulated in the set time period.

S509, determining the correlation control intersection with the proportion larger than the preset proportion threshold value as a target correlation control intersection.

S5101, determining a green light time length adjusting proportion of the intersection to be adjusted according to the control cut-off time length and the preset green signal ratio.

S5102, determining the green light time length adjusting proportion of each upstream target control intersection according to the green light time length adjusting proportion of the intersection to be adjusted and the cascade relation between each upstream target control intersection and the intersection to be adjusted.

S5111, determining the adjusting flow distributed to each downstream target control intersection according to the total control quantity of the road section to be adjusted and the traffic flow distribution relation between the upstream target control intersection and the downstream target control intersection.

S5112, determining the green light time length adjusting proportion of the downstream first-level target control intersection according to the adjusting flow distributed to the downstream target control intersection and the vehicle flow of the downstream first-level target control intersection.

S5113, determining the green light time length adjusting proportion of each downstream target control intersection except the downstream first-level target according to the green light time length adjusting proportion of the downstream first-level target control intersection and the cascade relation between each downstream target control intersection and the downstream first-level target control intersection.

S512, if the first green light time length adjusting proportion larger than the maximum value in the adjusting proportion threshold range exists, updating the first green light time length adjusting proportion by using the maximum value; and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold range exists, updating the second green light time length adjusting proportion by using the minimum value.

S513, the method is applied to the adjustment of the green light time length of the corresponding intersection in the adjustment proportion threshold range.

It should be noted that S5101-S5102 are determination processes of the green light time length adjustment ratios of the intersection to be adjusted and each upstream target control intersection, and S5111-S5113 are determination processes of the green light time length adjustment ratios of each downstream target control intersection. There is no obvious precedence between the two processes, and both processes can be performed simultaneously. The step of determining the control interception duration of the control direction to be adjusted in the adjustment process and the step of determining the target-associated control intersection have obvious business precedence relationship, and the two steps can be performed simultaneously, and fig. 5 is only an example.

In summary, according to the embodiment of the application, an overflow identification area is defined at a specific position, overflow judgment is carried out by setting a threshold value according to the vehicle density and the average speed in the area, and the intersection to be adjusted immediately responds after overflow by adjusting the signal lamp state of the intersection to be adjusted and the associated intersection when the overflow is judged; and the overflow control is carried out in a mode of synchronous upstream and downstream association control intersection linkage control, so that congestion transfer is avoided, traffic congestion is relieved, and the overflow control is supported to be continuously applied to the ground.

As shown in fig. 6, based on the same inventive concept, an embodiment of the present invention provides a control apparatus for traffic signals, including a first determining module 61, a first adjusting module 62, a second determining module 63, a third determining module 64, and a second adjusting module 65.

The first determining module 61 is used for determining a road section to be adjusted and an intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed in the area to be identified of the road section; the road section to be adjusted is a road section which needs to be subjected to overflow adjustment; the intersection to be adjusted is the first control intersection in the upstream direction of the road section to be adjusted;

the first adjusting module 62 is configured to adjust a green light signal of the to-be-adjusted control direction according to a relation between a remaining green light time of the to-be-adjusted control direction of the to-be-adjusted road segment at the current time and a preset time threshold; determining the control interception time length of the control direction to be adjusted in the adjusting process;

the second determining module 63 is configured to determine, in the association control intersection of the intersection to be adjusted, a target association control intersection of the intersection to be adjusted based on a ratio of traffic flow passing through the road section to be adjusted from each association control intersection in the set time period to a total traffic flow of the road section to be adjusted; the target association control intersection comprises an upstream target control intersection and a downstream target control intersection;

a third determining module 64, configured to determine a green light time length adjustment ratio of the intersection to be adjusted and green light time length adjustment ratios of upstream target control intersections in the target associated intersections according to the control interception time length, and determine a green light time length adjustment ratio of downstream target control intersections in the target associated control intersections according to the total control quantity of the road section to be adjusted; the total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in a set time period;

and the second adjusting module 65 is configured to adjust the green light duration of the corresponding intersection according to the green light duration adjusting ratio.

in an area to be identified of a road section, determining the space density and the average speed of vehicles which are detected periodically;

and if the space density of the vehicles in the continuous first preset duration range is greater than a first preset density threshold value and the average speed of the vehicles is less than a first average speed threshold value, determining that the road section to which the area to be identified belongs is the road section to be adjusted and the crossing of the coming direction of the road section to be adjusted is the crossing to be adjusted.

In some exemplary embodiments, the first adjustment module 62 is specifically configured to:

according to the phase sequence of the intersection to be adjusted, when the green light duration of the previous direction of the control direction to be adjusted is ended, determining the remaining green light duration of the control direction to be adjusted;

if the road section to be adjusted meets the dissipation condition and the remaining green light time of the control direction to be adjusted is longer than the preset green light time, switching the red light signal of the control direction to be adjusted into a green light signal;

wherein the dissipation conditions include:

In some exemplary embodiments, the second determining module 63 is specifically configured to:

determining the traffic flow of each associated control intersection entering and exiting the road section to be regulated in the associated control intersections of the intersections to be regulated within a set time period;

determining the proportion of the traffic flow of each associated control intersection to the total traffic flow of the road section to be adjusted in a set time period;

and determining the associated control intersection with the proportion larger than the preset proportion threshold value as the target associated control intersection.

In some exemplary embodiments, the third determining module 64 is specifically configured to:

determining the green light time length adjusting proportion of the intersection to be adjusted according to the control cut-off time length and the preset green signal ratio;

In some exemplary embodiments, the method further includes updating, before the green light time duration of the corresponding intersection is adjusted by applying each green light time duration adjustment ratio, if there is a first green light time duration adjustment ratio that is greater than a maximum value within an adjustment ratio threshold range, the first green light time duration adjustment ratio is updated by applying the maximum value; and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold range exists, updating the second green light time length adjusting proportion by using the minimum value.

Since the apparatus is the apparatus in the method in the embodiment of the present invention, and the principle of the apparatus for solving the problem is similar to that of the method, the implementation of the apparatus may refer to the implementation of the method, and repeated details are not repeated.

Based on the same inventive concept, an embodiment of the present invention provides a control device of a traffic signal, which includes a processor.

The processor is configured to perform:

adjusting a green light signal of the control direction to be adjusted according to the relation between the residual green light time of the control direction to be adjusted of the road section to be adjusted at the current moment and a preset time threshold; determining the control interception time length of the control direction to be adjusted in the adjusting process;

in the association control intersections of the intersections to be adjusted, determining the target association control intersections of the intersections to be adjusted based on the proportion of the traffic flow passing through the sections to be adjusted from each association control intersection in the set time period to the total traffic flow of the sections to be adjusted; the target association control intersection comprises an upstream target control intersection and a downstream target control intersection;

determining a green light time length adjusting proportion of the intersection to be adjusted and green light time length adjusting proportions of all upstream target control intersections in the target associated intersections according to the control closure time length, and determining a green light time length adjusting proportion of all downstream target control intersections in the target associated control intersections according to the total control quantity of the road section to be adjusted; the total control quantity of the road section to be regulated is determined according to the total traffic flow quantity and the dissipation quantity in a set time period;

In some exemplary embodiments, the processor is configured to perform:

wherein the dissipation conditions include:

In some exemplary embodiments, the processor is configured to perform:

In some exemplary embodiments, the processor is further configured to perform:

before each green light time length adjusting proportion is applied to adjust the green light time length of the corresponding intersection, if a first green light time length adjusting proportion larger than the maximum value in the adjusting proportion threshold value range exists, the maximum value is applied to update the first green light time length adjusting proportion; and if the second green light time length adjusting proportion smaller than the minimum value in the adjusting proportion threshold range exists, updating the second green light time length adjusting proportion by using the minimum value.

The embodiment of the invention also provides a computer storage medium, wherein computer program instructions are stored in the computer storage medium, and when the instructions run on a computer, the computer is enabled to execute the steps of the network distribution method of the electronic home equipment.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A control device for a traffic signal, comprising a processor:

the processor is configured to perform:

2. The control device of claim 1, wherein the processor is configured to perform:

3. The control device of claim 1, wherein the processor is configured to perform:

wherein the dissipation conditions include:

4. The control device of claim 1, wherein the processor is configured to perform:

5. The control device of claim 1, wherein the processor is configured to perform:

6. The control device of claim 1, wherein the processor is configured to perform:

7. The control device of any of claims 1-6, wherein the processor is further configured to perform:

8. A method of controlling a traffic signal, comprising:

9. The method according to claim 8, wherein the determining of the road section to be adjusted and the intersection to be adjusted according to the periodically detected vehicle space density and the vehicle average speed in the area to be identified in the road section comprises:

10. The method as claimed in claim 8, wherein the determining the control interception time length of the control direction to be adjusted according to the remaining green light time length of the control direction to be adjusted of the road section to be adjusted at the current moment, and applying the control interception time length to adjust the green light time length of the control direction to be adjusted comprises:

wherein the dissipation conditions include: