A traffic management method for prioritizing vehicle passage

Abstract

This invention relates to the field of traffic control. It provides a vehicle priority traffic management method, comprising: constructing a vehicle priority event level table; receiving priority requests from users; setting a priority event level for each priority request; processing priority requests according to time and priority; calculating the optimal passage plan for each priority request; and after a priority request is completed, recording the request's origin, destination, passage plan, traffic impact, passage time, and event occurrence period, and determining whether the passage plan is a priority plan for the corresponding time period, origin, and destination. If so, the preferred road segment is saved to a set of preferred plans. This invention can centrally process various priority requests and sort conflicting requests according to priority, thereby improving execution efficiency. Data from each priority request is recorded and compared to select the optimal plan, which can then be used as a reference for subsequent priority requests.

Description

Technical Field

[0001] This invention relates to the field of traffic control, and specifically to a traffic management method for prioritizing vehicle passage. Background Technology

[0002] With urbanization and increased traffic flow, properly handling vehicle priority passage requests has become a crucial means of improving urban road traffic efficiency. Current vehicle priority passage technologies utilize intersection traffic facilities, vehicle positioning equipment, and communication technologies to prioritize vehicle control over traffic lights, thereby processing vehicle priority passage requests.

[0003] The main problems with current vehicle priority control are as follows: First, priority control often adopts an absolute priority approach, completely disregarding the impact on the passage of commuter vehicles. In contrast, relative priority approaches rely on the arrival time of priority requesting vehicles at intersections when considering priority order, which is difficult to correlate with the actual traffic conditions at intersections. Second, when multiple routes and multiple tasks are executed concurrently, the reliance on arrival priority order makes it impossible to optimize and adjust routes in a timely manner when arrival times conflict, which is not conducive to the planning and execution of priority tasks. Third, the optimal solutions for handling vehicle priority requests in historical data cannot be reused. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a traffic management method for prioritizing vehicle passage.

[0005] The method includes:

[0006] S101, Construct a vehicle priority passage event level table;

[0007] S102 provides an interface to receive priority passage requests from users;

[0008] S103, set the priority event level for each priority access request, and check whether there is time overlap or coverage area overlap between the priority access requests. If there is no time overlap or coverage area overlap, the priority of the priority access request is the highest; define priority access requests with time overlap or coverage area overlap as conflict priority access request groups; prioritize the priority access requests in each conflict priority access request group.

[0009] S104, Process priority passage requests according to time and priority;

[0010] S105: Based on the time period, origin, and destination of the priority passage request, query the set of preferred solutions. If a preferred solution is found, execute the preferred solution to complete the priority passage request.

[0011] If the priority event level of a priority passage request is higher than the threshold, and the priority of the priority passage request is the highest, the priority passage request shall be executed using the absolute priority control passage scheme.

[0012] Otherwise, calculate whether there is a low-saturation route among the multiple alternative routes for the priority passage request. If so, execute the priority passage request using the green wave passage scheme on the route with the lowest saturation.

[0013] For priority passage requests that do not meet the above conditions, the route with the least computation time is selected and the general passage scheme is executed to complete the priority passage request.

[0014] Whether there is a low-saturation route among the multiple alternative routes refers to whether the saturation of the intersection through which the alternative route passes and the two adjacent intersections on the left and right sides of the intersection is less than 0.85.

[0015] S106 After a priority passage request is completed, the origin, destination, passage plan, traffic impact, passage time, and event occurrence time of the request are recorded. Based on the passage time and the traffic impact on the associated area, it is determined whether the passage plan is the priority plan for the corresponding time period, origin, and destination. If so, the preferred road segment is saved into the preferred plan set.

[0016] Furthermore, S101, construct a vehicle priority passage event level table, specifically including:

[0017] Vehicle priority event level Corresponding meaning 1 Very important 2 important 3 priority 4 Low priority

[0018] Furthermore, S102 provides interfaces to receive priority access requests from users, specifically providing telephone interfaces, SMS interfaces, web page interfaces, and WeChat mini-program interfaces.

[0019] Furthermore, the prioritization of priority requests within each conflict priority request group, as described in S103, specifically includes:

[0020] Within each conflict priority passage request group, vehicles with higher priority events have higher priority.

[0021] In each conflict priority passage request group, if the vehicle priority passage event level is the same, the one that submits the priority passage request first has higher priority.

[0022] Furthermore, the absolute priority control passage scheme described in S105 specifically refers to:

[0023] Calculate the travel time for all routes without considering the impact of traffic lights;

[0024] Select the route with the shortest travel time as the implementation route of the plan;

[0025] Five seconds before the target vehicle arrives at any intersection along the planned route, the traffic light in the direction of travel along the planned route at that intersection will be set to green.

[0026] Furthermore, the use of a green wave traffic scheme on the route with the lowest saturation, as described in S103, to execute the priority passage request specifically includes:

[0027] Select the route with the lowest saturation as the execution route of the plan;

[0028] When the target vehicle arrives at the first intersection of the route, the traffic light in the direction of travel at that intersection will be set to green.

[0029] Calculate the time t when the target vehicle arrives at the next intersection, based on the target vehicle's speed and the distance from its position to the next intersection.

[0030] If the traffic light in the direction of the next intersection is green at time t according to the preset rules, and the target vehicle can pass through the intersection at a constant speed during the time the traffic light remains green, then the traffic light at that intersection will not be modified.

[0031] Otherwise, modify the traffic light rules according to the scheme that has the least impact on the traffic at the intersection, so that the target vehicle can pass through the intersection at a constant speed at time t.

[0032] Furthermore, the determination of whether a travel plan is a priority plan for the corresponding time period, origin, and destination based on travel time and its impact on traffic in the associated area, as described in S106, specifically includes:

[0033] Read the travel time data between the destination and the origin during the event period from historical data, and calculate its average value;

[0034] Calculate the time efficiency ω of the priority passage request = passage time of the priority passage request / average value;

[0035] Define the intersections on the route of the priority passage request and the two adjacent intersections on the left and right as the associated area;

[0036] Compare the traffic operation index of road segments and the delay index of intersections within the relevant area before and after the priority passage request is executed;

[0037] If the change range of the traffic operation index and the delay index of the intersection is less than 10%, and ω is less than 70%, then the priority passage request is a priority passage plan based on the corresponding time period, origin, and destination.

[0038] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0039] This invention proposes a traffic management method for vehicle priority passage. It rationally plans priority routes based on actual road traffic conditions and adjusts for a series of emergencies during the task execution process through monitoring, thereby minimizing the impact on other vehicles and greatly improving the efficiency and safety of priority passage.

[0040] This invention centrally processes each priority passage request and sorts conflicting priority passage requests according to their priority, thereby improving execution efficiency.

[0041] This invention records and compares the data of each priority passage request, and selects the preferred solution, which can serve as a reference for subsequent priority passage requests. Attached Figure Description

[0042] Figure 1 This is a flowchart of a method provided in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Before describing the technical solutions of each embodiment of the present invention in detail, the terms and terms involved will be explained. In this specification, components with the same name or the same reference numerals represent similar or the same structures and are limited to illustrative purposes.

[0044] To implement the vehicle priority passage function, it is necessary to first define the priority passage event levels. Therefore, we need to construct a vehicle priority passage event level table to describe the levels of various different types of priority passage events. This table is categorized according to factors such as time urgency, and a corresponding event level can be assigned to each priority passage event. For example, for an emergency rescue vehicle, its priority should be "very important".

[0045] The following is an example of a vehicle priority event hierarchy table:

[0046] Vehicle priority event level Corresponding meaning 1 Very important 2 important 3 priority 4 Low priority

[0047] Secondly, this invention also needs to provide an interface to receive priority access requests, including interfaces such as telephone, SMS, webpage, and QQ mini-program. Priority access requests should include information such as the origin, destination, and time period of the request. Upon receiving the request, the server will process it and assign it a priority access event level.

[0048] Upon receiving a new priority passage request, a priority is assigned to it: The process involves checking for time or coverage overlap between the priority passage request and other priority passage requests. If there is no time or coverage overlap, the priority of this priority passage request is the highest. Priority passage requests with overlapping time or coverage are defined as conflicting priority passage request groups. Priority is then ranked within each conflicting priority passage request group. This ensures that even when conflicts exist among priority passage requests, a reasonable priority can be assigned to each request according to certain rules.

[0049] After all priority requests are assigned a priority, the vehicle priority request processing server processes the priority requests according to time and priority.

[0050] Considering factors such as traffic saturation, travel time, and minimizing the impact on overall traffic, calculate the optimal implementation plan:

[0051] Based on the time period, origin, and destination of the priority passage request, the system queries the set of preferred solutions. If a preferred solution is found, it is executed to complete the priority passage request.

[0052] If the priority event level of a priority passage request is higher than the threshold, and the priority of the priority passage request is the highest, the priority passage request shall be executed using the absolute priority control passage scheme.

[0053] Otherwise, calculate whether there is a low-saturation route among the multiple alternative routes for priority passage request. A low-saturation route refers to whether the saturation of the intersection the route passes through and the two adjacent intersections on the left and right is less than 0.85. If so, the green wave passage scheme is used to execute the priority passage request on the route with the lowest saturation.

[0054] For priority passage requests that do not meet the above conditions, the route with the least computation time is selected, and the general passage scheme is executed to complete the priority passage request.

[0055] After a priority passage request is completed, record the origin, destination, travel plan, traffic impact, passage time, and time period of the event.

[0056] Read the travel time data between the destination and the origin during the event period from historical data and calculate its average value; calculate the time efficiency ω of the priority passage request = travel time of the priority passage request / average value; define the intersections on the route of the priority passage request and the two adjacent intersections on the left and right as the associated area; compare the traffic operation index of the road segment and the delay index of the intersection in the associated area before and after the priority passage request is executed; if the change of the traffic operation index and the delay index of the intersection is less than 10% and ω is less than 70%, then the passage plan of the priority request is the priority plan for the corresponding time period, origin, and destination.

[0057] The following sections introduce the general traffic control scheme, the absolute priority control traffic control scheme, and the green wave traffic control scheme.

[0058] 1. General Passage Scheme

[0059] Predict the time it will take to travel from point A to point B. There are N routes from A to B, and the time t takes for route i to travel from A to B under specified traffic conditions over a given time period is denoted as t. iA-B Under the current road conditions, the shortest time is

[0060] Without altering the existing signal control strategy, the travel time for all routes under the current timing conditions is calculated, and the route with the minimum travel time is selected as the preferred route. There are two main methods for calculating travel time: one is prediction based on historical travel times, i.e., the average travel time of vehicles on all routes from point A to point B in the past; this method carries the risk of unforeseen events. The second method is to calculate the average travel time of the selected route based on the travel time to a designated intersection, combined with the set of routes where demand at the current intersection is concentrated. Regardless of the method used, the route with the minimum travel time across all routes is selected as the recommended route. This method does not affect the traffic structure of the routes, therefore, there is no need to change the existing signal timing.

[0061] 2. Passage control scheme with absolute priority

[0062] If a target vehicle is given a green light 5 seconds before arriving at an intersection along the route, allowing it to proceed in that direction without obstruction, this method has the greatest impact on other vehicles along the route. Therefore, adjustments to traffic signal timings at surrounding intersections must be considered. Although it's described as unobstructed passage, the actual traffic conditions along the route and the resulting losses for vehicles traveling on that route need to be considered. This is primarily based on the predicted travel time, i.e., the travel time from point A to point B at each node on each route (from the current intersection to the next intersection) under current road conditions. Because the vehicle is given a green light immediately upon reaching each intersection, the travel time T for route i (AB) is calculated as follows. ifor In the formula, j represents the road segment between intersections. Therefore, the optimal route selection is min(T1, T...). n The corresponding road segment. After route selection, the next step is to consider the interference of absolute right-of-way on other vehicles. Because the right-of-way on the priority route must be guaranteed, the right-of-way of intersecting roads is sacrificed. Therefore, while exercising the right-of-way on the priority road, the impact factor of adjacent intersections must be calculated. When the impact factor is greater than 0.1, signal optimization adjustments need to be made at adjacent intersections with an impact factor greater than 0.1, combined with traffic guidance measures, while guaranteeing the priority road. The impact factor is calculated as follows: Where m i临h1后 This represents the traffic flow in the intersecting directions at the adjacent intersections i and h1 after the implementation of the plan. Similarly, m... i临h1前 This indicates the traffic flow in the intersecting directions of the adjacent intersection i and intersection h1 before the implementation of the plan.

[0063] The signal strategy adjustment method is to customize the strategy based on the changed traffic demand to meet the demand allocation when there is a sudden change in traffic volume composition. It mainly includes two types: one is to reduce the flow of vehicles entering from intersecting roads, that is, to reduce the green light ratio in the corresponding direction; the other is to guide some of the vehicles about to enter to other roads that will not be congested through traffic guidance, and guide vehicles to choose other routes.

[0064] 3. Green Wave Traffic Plan

[0065] Setting up a green wave along a specified path is suitable for situations where the traffic volume on the specified road and in the surrounding area is not very high, i.e., no intersection saturation exceeds 0.85 within the selected range. In this case, a relative priority approach is adopted at the first intersection. That is, instructions are issued to the traffic signal controller of the first intersection based on Beidou positioning. When a vehicle is about to arrive, if the current first intersection is red, the red light at the current intersection is ended in the background by event insertion. That is, after 3 seconds of green flashing + 3 seconds of yellow flashing, the intersection turns green. When the vehicle leaves the intersection, the green light ends and the normal control strategy of the intersection is restored. The route with the lowest saturation is selected as the execution route of the plan.

[0066] Calculate the time t when the target vehicle arrives at the next intersection, based on the target vehicle's speed and the distance from its position to the next intersection.

[0067] If the traffic light in the direction of the next intersection is green at time t according to the preset rules, and the target vehicle can pass through the intersection at a constant speed during the time the traffic light remains green, then the traffic light at that intersection will not be modified.

[0068] Otherwise, modify the traffic light rules according to the scheme that minimizes the impact on traffic at the intersection, so that the target vehicle can pass through the intersection at a constant speed at time t. Once the vehicle has completely left the route, restore the initial state of each intersection on the current route.

[0069] This invention proposes a traffic management method for vehicle priority passage. This method combines actual road traffic conditions with rational planning of priority passage routes and monitoring of various unforeseen circumstances during task execution, minimizing the impact on other vehicles while significantly improving the efficiency and safety of priority passage. This invention can centrally process individual priority passage requests and prioritize conflicting requests according to their priority, thereby improving execution efficiency. Data from each priority passage request is recorded and compared to select the optimal solution, which can then be used as a reference for subsequent priority passage requests.

[0070] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A traffic management method for prioritizing vehicle passage, characterized in that, Includes the following steps: S101, Construct a vehicle priority passage event level table; S102 provides an interface to receive priority passage requests from users; S103, set the priority event level for each priority access request, and check whether there is time overlap or coverage area overlap between the priority access requests. If there is no time overlap or coverage area overlap, the priority of the priority access request is the highest; define priority access requests with time overlap or coverage area overlap as conflict priority access request groups; prioritize the priority access requests in each conflict priority access request group. S104, Process priority passage requests according to time and priority; S105: Based on the time period, origin, and destination of the priority passage request, query the set of preferred solutions. If a preferred solution is found, execute the preferred solution to complete the priority passage request. If the priority event level of a priority passage request is higher than the threshold, and the priority of the priority passage request is the highest, the priority passage request shall be executed using the absolute priority control passage scheme. Otherwise, calculate whether there is a low-saturation route among the multiple alternative routes for the priority passage request. If so, execute the priority passage request using the green wave passage scheme on the route with the lowest saturation. For priority passage requests that do not meet the above conditions, the route with the least computation time is selected and the general passage scheme is executed to complete the priority passage request. Whether there is a low-saturation route among the multiple alternative routes refers to whether the saturation of the intersection through which the alternative route passes and the two adjacent intersections on the left and right sides of the intersection is less than 0.

85. S106 After a priority passage request is completed, the origin, destination, passage plan, traffic impact, passage time, and event occurrence time of the request are recorded. Based on the passage time and the traffic impact on the associated area, it is determined whether the passage plan is a priority plan for the corresponding time period, origin, and destination. If so, the preferred road segment of the priority plan is saved into the preferred plan set.

2. The vehicle priority traffic management method as described in claim 1, characterized in that, S101, Construct a vehicle priority passage event level table, specifically including:

3. The vehicle priority traffic management method as described in claim 1, characterized in that, S102 provides interfaces to receive priority access requests from users, specifically providing telephone interfaces, SMS interfaces, web page interfaces, and WeChat mini-program interfaces.

4. The vehicle priority traffic management method as described in claim 1, characterized in that, S103 describes prioritizing priority requests within each conflict priority request group, specifically including: Within each conflict priority passage request group, vehicles with higher priority events have higher priority. In each conflict priority passage request group, if the vehicle priority passage event level is the same, the one that submits the priority passage request first has higher priority.

5. The vehicle priority traffic management method as described in claim 1, characterized in that, The absolute priority control passage scheme described in S105 specifically refers to: Calculate the travel time for all routes without considering the impact of traffic lights; Select the route with the shortest travel time as the implementation route of the plan; Five seconds before the target vehicle arrives at any intersection along the planned route, the traffic light in the direction of travel along the planned route at that intersection will be set to green.

6. The vehicle priority traffic management method as described in claim 1, characterized in that, The use of a green wave traffic scheme to execute the priority passage request on the route with the lowest saturation, as described in S103, specifically includes: Select the route with the lowest saturation as the execution route of the plan; When the target vehicle arrives at the first intersection of the route, the traffic light in the direction of travel at that intersection is set to green. Calculate the time t when the target vehicle arrives at the next intersection, based on the target vehicle's speed and the distance from its position to the next intersection. If the traffic light in the direction of the next intersection is green at time t according to the preset rules, and the target vehicle can pass through the intersection at a constant speed during the time the traffic light remains green, then the traffic light at that intersection will not be modified. Otherwise, modify the traffic light rules according to the scheme that has the least impact on the traffic at the intersection, so that the target vehicle can pass through the intersection at a constant speed at time t.

7. The vehicle priority traffic management method as described in claim 1, characterized in that, The method described in S106 for determining whether a travel plan is a priority plan for the corresponding time period, origin, and destination based on travel time and its impact on traffic in the associated area specifically includes: Read the travel time data between the destination and the origin during the event period from historical data, and calculate its average value; The time efficiency ω of the priority passage request is calculated as: passage time of the priority passage request / average value; Define the intersections on the route of the priority passage request and the two adjacent intersections on the left and right as the associated area; Compare the traffic operation index of road segments and the delay index of intersections within the relevant area before and after the priority passage request is executed; If the change range of the traffic operation index and the delay index of the intersection is less than 10%, and ω is less than 70%, then the passage plan for the priority passage request is the priority plan for the corresponding time period, origin, and destination.

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