Quasi all-weather passing-oriented highway simulation platform rapid construction method

Abstract

The invention discloses a quick construction method for a quasi all-weather passing-oriented highway simulation platform, and belongs to the field of highway management and control. The method comprises the following steps of: constructing an emergency vehicle driving scene of a SUMO-based simulation platform by the highway simulation platform for cooperative vehicle and road management and control; and according to actual road network data and based on different input flows, simulating an emergency avoidance vehicle, simulating a lane changing guide strategy adopting the emergency avoidance vehicle, an emergency lane pre-emptying double-layer model contained in the lane changing guide strategy and a strategy not adopting the lane changing guide strategy respectively, and comparing travel information of the emergency vehicle and travel information of a vehicle in front of the emergency vehicle. The lane changing guide strategy for avoiding the emergency vehicle and the included emergency lane pre-emptying double-layer model can obviously improve the speed of the emergency vehicle and reduce the travel time, so that the emergency rescue time is shortened, and the practicability and the stability of the model are verified.

Description

Technical Field

[0001] The present invention belongs to the field of highway management and control, and more specifically, relates to a novel method for quickly constructing a highway simulation platform. Background Art

[0002] Traffic congestion not only causes traffic accidents, travel delays, environmental pollution and other problems, but also affects emergency vehicles performing emergency tasks. When natural disasters or man-made disasters occur, emergency vehicles must reach the accident site via roads as soon as possible to reduce the loss of life and property caused by the emergency.

[0003] In order to effectively improve the traffic efficiency of emergency vehicles, emergency vehicles enjoy the right of way when performing emergency operations, and other vehicles must actively give way to emergency vehicles. my country's laws and regulations require that as long as traffic safety is guaranteed, emergency vehicles are not subject to restrictions such as roads, directions, speeds, and traffic signals, and other vehicles and personnel must give way to them in an emergency. The United States also clearly states that general vehicles must slow down or stop on both sides of the road to give way to emergency vehicles.

[0004] Although my country's current road transport regulations have strictly regulated the right of priority for emergency vehicles, in real life, especially under certain special conditions, emergency vehicles do not enjoy the right of priority. The priority of emergency vehicles is determined by the actual situation. With the rapid development of communication technology, vehicle-road cooperative technology has become more advanced. Vehicle-road cooperative technology is a key technology of intelligent transportation system (ITS). It is a real-time and bidirectional information exchange between the on-board intelligent system and the roadside unit. The control center analyzes the data and generates corresponding control strategies to coordinate vehicles, thereby improving the safety performance of vehicles. Due to the synergy between vehicle-to-vehicle (V2V) and vehicle-to-road (V2I), the traffic operation efficiency is improved, and the lane change guidance strategy is easier to implement in a vehicle-road cooperative environment than in a traditional environment. Summary of the invention

[0005] The purpose of the present invention is to provide a method for quickly constructing a highway simulation platform for quasi-all-weather traffic. By applying a lane-changing safety distance model and lane-changing trajectory planning, and applying the ACC's following model in the simulation, based on a lane pre-clearing double-layer model, the optimal lane-changing trajectory of the model result is simulated, and the simulation is optimized in an online loop. The lane-changing trajectory of the lane-changing vehicle is planned at the micro level, and online real-time and precise control of the affected vehicles is achieved, so as to guide the lane-changing vehicle to change lanes.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for rapidly constructing a highway simulation platform for quasi-all-weather traffic, comprising:

[0008] A highway simulation platform for vehicle-road collaborative control, building a SUMO-based simulation platform for emergency vehicle approaching scenarios;

[0009] According to the actual road network data and based on different selected input flows, the emergency vehicle avoidance is simulated;

[0010] The lane change guidance strategy for avoiding emergency vehicles and the double-layer model of emergency lane pre-clearance included in it are simulated separately with and without this strategy; the travel information of the emergency vehicle and the vehicle in front of the emergency vehicle are compared.

[0011] Furthermore, by applying the lane change safety distance model and lane change trajectory planning, and applying the ACC following model in the simulation, the optimal lane change trajectory of the model results is simulated based on the lane pre-clearing double-layer model, and the online cycle optimization simulation is performed.

[0012] Furthermore, in the constructed scenario, the upstream of the road was extended by 250-400m as a buffer area for vehicle input.

[0013] Furthermore, when selecting different input flows for simulation, by verifying the effectiveness and stability of the model under different traffic flow conditions and obtaining the maximum traffic flow that the road section can withstand, when simulating the lane change guidance strategy that adopts the avoidance of emergency vehicles, several input flows are selected equidistantly between the maximum flow that achieves the greatest effect and the maximum flow for simulation.

[0014] Furthermore, when evaluating the simulation results, the emergency vehicle and the vehicle ahead of it are evaluated separately.

[0015] Furthermore, the evaluation indicators for evaluating emergency vehicles include: speed of each step, average speed, travel time, delay, and number of lane changes; the evaluation indicators for evaluating the front vehicle include: average speed, average travel time, and average delay.

[0016] Furthermore, when simulating avoiding emergency vehicles according to actual road network data, two situations of whether to adopt a lane change guidance strategy for avoiding emergency vehicles are simulated based on the actual road network data.

[0017] Furthermore, when simulating the avoidance of emergency vehicles according to the different selected input flow rates, several selected input flow rate situations are simulated based on the road conditions of the actual road network, and simulations in each case without adopting the lane change guidance strategy for avoiding emergency vehicles are added as a control group.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention proposes a method for quickly constructing a highway simulation platform for vehicle-road collaborative control. The method is based on the SUMO simulation platform to build a simulation scene for the lane change guidance method of the front vehicle to avoid the emergency vehicle, and the Traci-Python interface is used to realize the real-time data collection and online control of the vehicle. By applying the lane change safety distance model and lane change trajectory planning, and applying the ACC following model in the simulation, the optimal lane change trajectory of the model result is simulated based on the lane pre-clearance double-layer model, and the online cyclic optimization simulation is performed to plan the lane change trajectory of the lane-changing vehicle from a microscopic perspective, realize online real-time and precise control of the affected vehicles, and realize lane change guidance for the lane-changing vehicle.

[0020] 2. The lane change guidance strategy for avoiding emergency vehicles and the double-layer model of emergency lane pre-clearance included in it can significantly increase the speed of emergency vehicles and reduce travel time, thereby shortening the time for emergency rescue. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the simulation scene;

[0023] Figure 2 This is a schematic diagram of the road grid map;

[0024] Figure 3 It is a scatter plot of flow change;

[0025] Figure 4 A schematic diagram of emergency avoidance using a lane change guidance strategy;

[0026] Figure 5 A line graph showing the change in speed of the emergency vehicle when the lane change guidance strategy is adopted;

[0027] Figure 6 It is a line graph showing the change in the speed of emergency vehicles under different input flows;

[0028] Figure 7 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 900pcu / h;

[0029] Figure 8 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 1800pcu / h;

[0030] Fig. 9 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 2700pcu / h;

[0031] Fig.10 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 3600pcu / h;

[0032] Fig.11 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 3600pcu / h;

[0033] Fig.12 Schematic diagram of the lane changing process for vehicles that need to change lanes under different circumstances;

[0034] Fig.13 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 4500pcu / h;

[0035] Fig.14 Schematic diagram of the lane changing process of the vehicle ahead with the guidance strategy when the input flow rate is 5400pcu / h. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] A method for rapidly constructing a highway simulation platform for quasi-all-weather traffic comprises the following steps:

[0038] Step 1: Scene Construction

[0039] The NetEdit scene in the SUMO simulation platform (SUMO version 1.7.0) was used to build the scene. In order to focus on the research object, a one-way 3-lane highway was set. The lane width was 3.5m and the road speed limit was 120km / h according to the actual road. The morning peak period of 8:00-9:00 was selected for simulation. The simulation time was 1 hour and the simulation was preheated for 10 minutes to avoid data errors caused by the lack of vehicles on the road. The scene built is as follows Figure 1 As shown;

[0040] Since a grid map is required in the double-layer model, the map is rasterized with a grid size of 3.5 m (lane width) * 30 m (length along the road direction).

[0041] In order to ensure data accuracy and vehicle status when entering the road, a buffer area of ​​300m is extended upstream of the road as vehicle input. Figure 2 shown.

[0042] Step 2: Parameter selection

[0043] When defining vehicle information, you need to note that vehicles are divided into two types: ordinary smart vehicles and emergency vehicles. Set parameters for the two types of vehicles separately. Define the parameters of the two types of vehicles in the rou.xml file. The parameters that must be defined are shown in Table 4-1.

[0044] Table 4-1 Meaning of vehicle parameters

[0045]

[0046] When inputting traffic, the two vehicle types are set separately, and the vehicle ID of the emergency vehicle is set to veh_b1, and a separate name is set to facilitate the subsequent acquisition of the emergency vehicle's travel information. In the vehicle-road collaborative environment, the ACC following model is selected as the following model because it has the advantages of being timely, accurate, stable, and safe. In the simulation, the selected road section is a one-way three-lane section of the highway, and the maximum speed of the highway is 120km / h. The minimum vehicle spacing and minimum headway time in the ACC following model are taken according to the default values;

[0047] Step 3: Enter the traffic

[0048] The input flow in SUMO is determined by the flow tag of rou.xml, and the actual road network data and vehicle information are input into the tag for simulation, as simulation 1.

[0049] The simulation experiment not only needs to satisfy the simulation of the actual road network data of the selected period, but also needs to conduct a more in-depth verification of the model. Therefore, different traffic flows are selected as input traffic flows for simulation, as simulation 2.

[0050] Simulation 1 is a simulation of the actual road network. This simulation inputs the data of the actual road network, selects a highway with three lanes in one direction in the PeMS20.0.0 database, and simulates the morning peak period of 8:00-9:00. The simulation time is 1 hour, but the road network needs to be preheated, and 7:50-8:00 is selected for a total of 10 minutes for preheating. During the simulation period, the flow rate is input every 5 minutes, and the average speed of the road section is set as the vehicle speed. The specific input flow rate and speed are shown in Table 4-2.

[0051] Table 4-2 Input flow of simulation 1

[0052]

[0053] Simulation 2 will select different input flows for simulation to verify the effectiveness and stability of the model under different traffic flow conditions. Obtaining the maximum traffic flow that the road section can withstand is the premise for selecting the input flow reasonably. Therefore, the road network is simulated according to the simulation scenario and the average vehicle speed of the actual road network, and the flow input is continuously increased to obtain the following Figure 3 The flow rate changes shown in the figure show that when the average speed of the section is the actual average speed of the section, the maximum flow rate of the section is 5400 pcu / h;

[0054] In the study of emergency vehicle avoidance guidance strategy, the flow rate with the greatest effect is the maximum flow rate of the road section (n lane -1) / n lane , the corresponding flow rate in the simulation scenario is 3600pcu / h, so 3600pcu / h is selected to verify the effectiveness of the model. In addition, in order to test the flow rate exceeding the maximum flow rate (n lane -1) / n lane In order to improve the effectiveness of the strategy, the maximum flow rate of 5400pcu / h that the road section can withstand was selected first.

[0055] Based on the selected 3600pcu / h and 5400pcu / h, in order to verify the effectiveness of the model under different flow conditions, the input flow is selected at intervals of 900pcu / h. In summary, 6 input flows of 900pcu / h, 1800pcu / h, 2700pcu / h, 3600pcu / h, 4500pcu / h, and 5400pcu / h are selected for simulation. The specific input data are shown in Table 4-3.

[0056] Table 4-3 Input flow of simulation 2

[0057]

[0058] S4. Determine the evaluation indicators for highway simulation platform design

[0059] The goal of the highway simulation platform is to enable the emergency vehicle to travel through the road section at the expected speed without changing lanes and to minimize the impact on the vehicle in front during emergency avoidance. Therefore, when evaluating the simulation results, the emergency vehicle and the vehicle in front of it are evaluated separately;

[0060] Among them, the selection of emergency vehicle evaluation indicators

[0061] The evaluation of emergency vehicles is mainly based on the goal, focusing on not changing lanes and driving close to the expected speed. The selected indicators are:

[0062] (1) Speed ​​of each step (step length is 1 s): This indicator can observe the speed change of the emergency vehicle when passing through the road section and evaluate the emergency avoidance strategy more accurately.

[0063] (2) Average speed: This indicator can be used to evaluate the overall speed of emergency vehicles on the road section.

[0064] (3) Travel time: This indicator can assist the average speed indicator to evaluate the overall speed of emergency vehicles on the road section.

[0065] (4) Delay: This indicator provides a more accurate evaluation of the overall operating efficiency of emergency vehicles within the road section.

[0066] (5) Number of lane changes: This indicator observes whether the emergency vehicle changes lanes.

[0067] Selection of evaluation index for the vehicle ahead

[0068] The evaluation of the vehicle ahead of the emergency vehicle is mainly based on the operating efficiency of the vehicle ahead and the overall operating efficiency of the road section. The selected indicators are:

[0069] (1) Average speed: This indicator is compared with the average speed under normal conditions to analyze the impact on the running speed of the vehicle ahead.

[0070] (2) Average travel time: This indicator assists the average speed in evaluating the traffic efficiency of the vehicles ahead.

[0071] (3) Average delay: This indicator provides a more accurate evaluation of the overall traffic efficiency of a road section.

[0072] S5. Analysis of simulation results of highway simulation platform

[0073] Based on the selected parameters, the model is simulated, two types of simulations are simulated respectively, and the output results are processed to obtain evaluation indicators. The simulation results are analyzed in detail as follows:

[0074] For simulation 1: Based on actual road network data

[0075] The effectiveness of the model is verified by comparing whether the lane change guidance strategy for avoiding emergency vehicles is adopted or not. Therefore, two situations are simulated based on actual road network data: whether the lane change guidance strategy for avoiding emergency vehicles is adopted or not.

[0076] When the lane change guidance strategy for avoiding emergency vehicles is not adopted, if there is a vehicle in front of the emergency vehicle and the distance to the front vehicle is too small, causing the emergency vehicle to start to slow down, a lane change request is sent to the emergency vehicle or the front vehicle. First, consider the emergency vehicle's lane change. If the target gap for the emergency vehicle's lane change does not meet the minimum safety distance, the emergency vehicle sends a lane change signal and changes lanes through multi-vehicle coordinated lane change. However, if the multi-vehicle coordinated lane change conditions are not met, consider the vehicle in front of the emergency vehicle for multi-vehicle coordinated lane change. If none of the lane change conditions are met and lane change is impossible, then follow the vehicle in front.

[0077] In the simulation of the lane change guidance strategy for avoiding emergency vehicles, the traffic volume and average vehicle speed of the actual road network are used as input data for simulation. When the emergency vehicle enters the simulated road section, the initial road state is as follows: Figure 4 In the figure, the emergency vehicle is located in lane 0. The vehicle in front needs to make way for the emergency vehicle. After the road is gridded, the 1500m section is divided into 150 grids. After model calculation and processing, the following is obtained: Figure 4 The target state shown in b) is obtained, and all vehicles that need to change lanes and their target positions are obtained. The travel information of the emergency vehicle and the vehicle in front of it is collected and processed through simulation, and the simulation results are analyzed and compared.

[0078] Although the lane-changing process is dynamic, its relative position remains unchanged. In order to express its relative position more clearly, Figure 4 In the expression, the vehicle in the grid numbered 6 on lane 0 is expressed as the coordinate (6,0) in the grid map. Similarly, there is a vehicle on (4,1). The vehicle on (6,0) needs to change lanes, and the longitudinal speed remains unchanged when changing lanes, but the lateral speed changes, so the longitudinal relative position with the vehicle on (4,1) remains unchanged. For a clearer expression, its target position is expressed in the (6,1) grid. All the following figures of this type are expressed in this way.

[0079] (1) Evaluation and analysis of emergency vehicle driving status

[0080] The speed of the emergency vehicle is evaluated. Based on the simulation, the speed of the emergency vehicle is determined by whether the lane change guidance strategy to avoid the emergency vehicle is adopted. The speed change of the emergency vehicle is as follows: Figure 5 shown.

[0081] Figure 5The time when the emergency vehicle enters the simulated road section is taken as zero, the horizontal axis is the simulation time, and the vertical axis is the speed of the emergency vehicle. It can be clearly seen that when the lane change guidance strategy for avoiding emergency vehicles is adopted, the emergency vehicle has been traveling at the expected speed of 33m / s. When the lane change guidance strategy for avoiding emergency vehicles is not adopted, the maximum speed of the emergency vehicle is 33m / s, the minimum speed is 20.07m / s, and the speed fluctuation is large. By comparison, it can be clearly seen that after adopting the lane change guidance strategy for avoiding emergency vehicles, the emergency vehicle can pass through the road section at the expected speed, and the traffic efficiency of the emergency vehicle is significantly higher than when the strategy is not adopted.

[0082] The travel information of the emergency vehicle is shown in Table 4-4. When the lane-changing guidance strategy for avoiding emergency vehicles is adopted, the average speed of the emergency vehicle is 5.7 m / s higher than that when it is not adopted. When the lane-changing guidance strategy for avoiding emergency vehicles is adopted, the speed variance of the emergency vehicle is 0 and there is no lane change, and the speed does not fluctuate. When the strategy is not adopted, the speed variance of the emergency vehicle is 23.70 and the lane change is 2 times. The two indicators are large, indicating that the speed of the emergency vehicle has obvious fluctuations. The greater the speed fluctuation, the more the vehicle needs to accelerate and decelerate longitudinally and laterally to ensure rapid passage. This speed fluctuation has an impact on safety, so there will be safety hazards during acceleration, deceleration and lane changing. Compared with not adopting the lane-changing guidance strategy for avoiding emergency vehicles, the travel time and delay are reduced by about 10s. The time it takes for the emergency vehicle to reach the emergency accident scene through this section is shortened by about 10s. This is only a 1500m simulated road. When the emergency vehicle passes through many such sections in the real road network, the time for emergency rescue can be greatly shortened. Therefore, the guidance strategy and the emergency lane pre-clearing double-layer model under this strategy are effective.

[0083] Table 4-4 Emergency vehicle travel information

[0084]

[0085] (2) Evaluation and analysis of the driving status of the vehicle ahead

[0086] The operating efficiency of the vehicle ahead of the emergency vehicle affects the overall operating efficiency of the road. According to Table 4-5, compared with not adopting the lane change guidance strategy to avoid emergency vehicles, the average speed is increased by 0.01m / s, the travel time is shortened by 0.05s, and the average delay is reduced by 0.03s. Therefore, the lane change guidance strategy to avoid emergency vehicles can reduce the impact on the road operating efficiency to a certain extent. Although the indicators do not change much under this actual road network data, there is some improvement.

[0087] Table 4-5 Travel information of the vehicle ahead

[0088]

[0089] In summary, under the actual road network data conditions, the lane change guidance strategy for avoiding emergency vehicles and the emergency lane pre-clearance double-layer model under this strategy significantly improved the driving speed of emergency vehicles, and the delay of emergency vehicles was reduced by 10s; the driving status of the vehicles in front of the emergency vehicles was also improved, and the average delay of the vehicles in front was reduced by 0.03s. Therefore, the lane change strategy can improve the traffic efficiency of emergency vehicles while having little impact on other vehicles on the road section, verifying the effectiveness of the model.

[0090] For simulation 2: Based on different input flows

[0091] Based on the road conditions of the actual road network, six cases with input flow rates of 900pcu / h, 1800pcu / h, 2700pcu / h, 3600pcu / h, 4500pcu / h and 5400pcu / h were simulated. In order to verify the superiority of the lane changing guidance strategy for avoiding emergency vehicles, simulations in which the lane changing guidance strategy for avoiding emergency vehicles was not adopted in each case were added as a control group, and data processing and analysis were performed on the simulation results.

[0092] Evaluation and analysis of emergency vehicle driving status

[0093] The speed of the emergency vehicle changes as Figure 6 As shown in the figure, it can be clearly seen that when the input flow rate is 900pcu / h, 1800pcu / h and 2700pcu / h, the speed of the emergency vehicle is the expected speed of 33m / s, which proves that the strategy is highly completed when the input flow rate is within the flow range of the road section where the strategy is most effective. When the input flow rate is the critical value of 3600pcu / h, which is the maximum effect of the strategy, the speed fluctuates twice, but basically maintains close to the expected speed. When the input flow rate is greater than 3600pcu / h, that is, when it exceeds the flow range of the road section where the strategy is most effective, the speed of the emergency vehicle fluctuates greatly, and the fluctuation increases with the increase of the input flow rate.

[0094] Table 4-6 Emergency vehicle trip information

[0095]

[0096]

[0097] Based on the emergency vehicle travel information results shown in Tables 4-6, the input flow is analyzed within, at the boundary, and outside the flow range of the section where the strategy has the greatest effect.

[0098] When the input flow is within the traffic range of the road section where the strategy has the greatest effect, that is, when the input flow is 900pcu / h, 1800pcu / h and 2700pcu / h, it can be clearly seen from Table 4-6 that the average speed of the emergency vehicle is the expected speed of 33m / s, and the speed variance is 0, the speed does not fluctuate, and compared with not adopting it, the travel time and delay are shortened, the number of lane changes of emergency vehicles is reduced, the safety of emergency vehicles is guaranteed, and the goal of the emergency vehicle pre-clearance double-layer model is met, verifying the effectiveness of the model. The lane change process of the three cases is as follows:

[0099] The input flow is 900pcu / h and the lane change guidance strategy for avoiding emergency vehicles is used to make the lane change process of the vehicle in front as follows Figure 7 As shown. Lane 0 where the emergency vehicle is located is the pre-cleared lane. All vehicles in lane 0 need to change lanes. Lane 0 is vacated for the emergency vehicle by changing lanes to lane 1. The target position of the vehicle that needs to change lanes is shown in the figure. In this case, the lane where the emergency vehicle is located can be vacated for the emergency vehicle, so the speed of the emergency vehicle is always maintained at the expected speed of 33m / s

[0100] The input flow is 1800pcu / h and the lane change guidance strategy for avoiding emergency vehicles is used to make the lane change process of the vehicle in front as follows Figure 8 As shown in the figure. Similar to the case where the input flow is 900pcu / h, the lane change process only requires the vehicle in lane 0 where the emergency lane is located to directly change lanes to lane 1 to complete the avoidance process. In this case, the lane where the emergency vehicle is located can be vacated for the emergency vehicle, so the speed of the emergency vehicle is always maintained at the expected speed of 33m / s

[0101] When the input flow rate is 2700pcu / h, the lane change guidance strategy of avoiding emergency vehicles is adopted to make the lane change process of the vehicle in front as follows: Fig. 9 Compared with the case where the input flow rate is 900 pcu / h, except for the vehicle in lane 0 directly changing lanes to lane 1 to complete the avoidance, when the horizontal coordinates of the grid map are 13, 35, and 47, the lane changing methods are as follows Fig.10 As shown in Figure 1, this process requires the vehicles in lane 1 and lane 0 to change lanes at the same time. The lane where the emergency vehicle is located is vacated for the emergency vehicle, so the speed of the emergency vehicle is always maintained at the expected speed of 33m / s.

[0102] When the input flow rate is the critical value of 3600pcu / h, which is the range of flow rates for the road section where the strategy has the greatest effect, as shown in Table 4-6, the average speed of emergency vehicles is 29.73m / s, the speed variance is 32.22, and the speed fluctuation is small. The travel time and delay increase compared with those within 3600pcu / h. Fig.11As shown, compared with the situation without the strategy, there has been a great improvement. The average speed of emergency vehicles has increased by 9.61m / s, the travel time has been reduced by 24s, and the delay has been reduced by 23.43s. The input flow of 3600pcu / h is at the critical value of the flow range of the road section where the strategy has the greatest effect, but the speed of the emergency vehicle has not always maintained the expected speed of 33m / s. This is because the input traffic flow is random at a certain moment, which determines that the traffic flow at each moment does not meet the optimal flow range of the road section. Therefore, the speed at some moments when driving on this road section is lower than the expected speed. Fig.12 As shown in the figure, when the number of grid columns is 24 and 37, the determination of the target vehicle position is the same. Taking the number of columns as 24 as an example, first, vehicle k at the map position (24,2) accelerates to (25,2), then vehicles i+1 and j change lanes at the same time, and finally vacate (25,0).

[0103] When the input flow is greater than the flow range of the road section where the strategy has the greatest effect, that is, when the input flow is 4500pcu / h and 5400pcu / h, it can be clearly seen from Table 4-6 that the average speed of emergency vehicles gradually decreases, but compared with not adopting the guidance strategy, the average speed of emergency vehicles is increased, the travel time is shortened, and the delay is reduced. Therefore, the driving state of emergency vehicles is optimized, and the effectiveness and stability of the guidance strategy are verified.

[0104] When the input flow rate is 4500pcu / h, the lane change guidance strategy of avoiding emergency vehicles is adopted to make the lane change process of the vehicle in front as follows: Fig.13 As shown in the figure, it is obvious that there are 10 vehicles in the lane where the emergency vehicle is located. They cannot change lanes through the lane change guidance strategy, and can only change lanes through multi-vehicle coordinated lane change after the guidance strategy is implemented. This is because the road section has a road density of more than 2 / 3, and there is no lane for the emergency vehicle, so the speed of the emergency vehicle cannot maintain the expected speed.

[0105] When the input flow rate is 5400pcu / h, the lane change guidance strategy of avoiding emergency vehicles is adopted to make the lane change process of the vehicle in front as follows: Fig.14 As shown in the figure, it can be clearly seen that the number of vehicles that cannot change lanes through the lane change guidance strategy is more than when the input flow is 4500pcu / h, and 21 vehicles cannot change lanes through the lane change guidance strategy. Therefore, the speed of the emergency vehicle cannot maintain the expected speed and the speed fluctuates.

[0106] The travel information of the vehicles ahead of the emergency vehicle is shown in Table 4-7. Compared with the normal driving road without emergency vehicles, when there is an emergency vehicle, when the input flow is within the range where the strategy can be maximized, that is, less than 3600pcu / h, the average speed of the vehicles ahead is reduced by 0.35m / s at most, the average travel time is increased by less than 2s at most, and the average delay is increased by 1.96s at most; when the input flow exceeds the maximum range where the strategy can be maximized, that is, more than 3600pcu / h, the average speed of the vehicles ahead is reduced by 0.82m / s at most compared with no emergency vehicles, and the travel time and average delay are increased by less than 5s at most. Therefore, after adopting the lane change guidance strategy to avoid emergency vehicles, the traffic operation status of the vehicles ahead of the emergency vehicle is affected, but the impact range is within an acceptable range, so this strategy is very practical.

[0107] Table 4-7 Travel information of the vehicle ahead

[0108]

[0109] In summary, emergency vehicles have the effect of improving the driving status of emergency vehicles under different road traffic conditions, and have little impact on the traffic operation status of vehicles in front of the emergency vehicles. lane -1) / n lane The lane change guidance strategy for avoiding emergency vehicles and the double-layer model of emergency lane pre-clearance included in the maximum flow range are adopted. The emergency vehicle passes quickly without changing lanes at a speed close to the expected speed of the emergency vehicle, and has little impact on the vehicle in front, which greatly shortens the time of emergency rescue. Therefore, the lane change guidance strategy for avoiding emergency vehicles is (n lane -1) / n lane It can play the greatest role within the maximum flow range and has strong practicality. However, if the input flow exceeds (n lane -1) / n lane When the maximum flow range is reached, the lane-changing guidance strategy for avoiding emergency vehicles and the double-layer model of emergency lane pre-clearance included in it can also improve the operation status of emergency vehicles and shorten the travel time. The impact on the vehicle ahead is also within an acceptable range. Therefore, the lane-changing guidance strategy for avoiding emergency vehicles also plays a role in high traffic, verifying its practicality. Through the simulation of the above six input flows, it is verified that the lane-changing guidance strategy for avoiding emergency vehicles and the double-layer model of emergency lane pre-clearance included in it can play a role under any flow, and it has strong practicality and stability.

[0110] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for rapidly constructing a highway simulation platform for quasi-all-weather traffic, characterized in that: include: A highway simulation platform for vehicle-road collaborative control, building a SUMO-based simulation platform for emergency vehicle approaching scenarios; According to the actual road network data and based on different selected input flows, the emergency vehicle avoidance is simulated; The lane change guidance strategy using emergency vehicle avoidance and the double-layer model of emergency lane pre-clearance included in it are simulated separately with and without this strategy; Compare the travel information of the emergency vehicle and the vehicle ahead of the emergency vehicle.

2. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 1 is characterized in that: By applying the lane change safety distance model and lane change trajectory planning, and applying the ACC following model in the simulation, the optimal lane change trajectory of the model results is simulated based on the lane pre-clearing double-layer model, and the simulation is optimized in an online cycle.

3. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 1 is characterized in that: In the constructed scene, the road upstream was extended by 250-400m as a buffer area for vehicle input.

4. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 1 is characterized in that: When selecting different input flows for simulation, by verifying the effectiveness and stability of the model under different traffic flow conditions and obtaining the maximum traffic flow that the road section can withstand, when simulating the lane change guidance strategy that adopts the avoidance of emergency vehicles, several input flows are selected equidistantly between the maximum flow that achieves the greatest effect and the maximum flow for simulation.

5. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 1 is characterized in that: When evaluating the simulation results, the emergency vehicle and the vehicle ahead of it are evaluated separately.

6. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 5 is characterized in that: The evaluation indicators for evaluating emergency vehicles include: speed of each step, average speed, travel time, delay, and number of lane changes; the evaluation indicators for evaluating the vehicles ahead include: average speed, average travel time, and average delay.

7. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 1 is characterized in that: When simulating avoiding emergency vehicles according to actual road network data, two situations are simulated based on the actual road network data: whether to adopt a lane change guidance strategy for avoiding emergency vehicles.

8. The method for rapidly constructing a highway simulation platform for quasi-all-weather traffic according to claim 7 is characterized in that: When simulating the avoidance of emergency vehicles according to the different selected input flows, several selected input flow conditions are simulated based on the road conditions of the actual road network, and simulations in each case without adopting the lane change guidance strategy for avoiding emergency vehicles are added as a control group.

Images