A simulation-based evaluation method for the impact of conflict behaviors in parking lots of comprehensive passenger transport hubs

Abstract

This paper proposes a simulation-based evaluation method for the impact of conflict behaviors in comprehensive passenger transport hub parking lots. The method first constructs a static environment, obtains a plan of the comprehensive passenger transport hub parking lot, classifies and identifies the roads and parking spaces in the lot, and performs rasterization processing; then generates dynamic vehicles, generates new vehicles entering the lot with Poisson probability distribution, and distributes the purpose of vehicle entry according to a certain proportion; combines static environment construction and dynamic vehicle generation, establishes the logic of vehicle movement in the lot, handles conflicts between vehicle movements, and finally evaluates and analyzes the impact of conflicts. The proposed research method can support the optimization management of comprehensive passenger transport hub parking lots.

Description

Technical Field

[0001] The invention belongs to the field of urban traffic planning, and in particular relates to a simulation-based method for evaluating the impact of conflict behaviors in a parking lot of a comprehensive passenger transport hub. Background Art

[0002] The operational efficiency of parking lots is a key factor in ensuring smooth traffic flow and the normal operation of urban functions. An efficient parking lot should be able to quickly guide vehicles in and out, reduce the time spent looking for parking spaces, and minimize congestion. This not only improves the driver's experience, reducing their waiting time and anxiety, but also helps reduce traffic congestion and emissions, thus having a positive impact on the environment. Therefore, improving the operational efficiency of parking lots is crucial to improving the overall efficiency and sustainable development of urban transportation.

[0003] The existing mainstream simulation mode mainly relies on vector simulation software, which has certain limitations in simulating vehicle movement, especially when describing non-compliant behaviors (such as driving against traffic). To overcome this challenge, we developed a simulation model based on rasterized parking lots. By dividing the parking lot into small grid units, the model can more accurately simulate the movement trajectory and non-compliant behaviors of vehicles, thereby achieving a comprehensive description of complex traffic scenes. This innovation not only improves the authenticity and accuracy of the simulation, but also provides a more powerful analysis tool for traffic planning and management. Summary of the invention

[0004] The purpose of the present invention is to provide a method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation. Under the premise of automatically identifying any parking lot and rasterizing it, the method sets a variety of typical conflicts and solves them and gives different entry purposes to the vehicles entering the parking lot, thereby obtaining the actual movement of vehicle traffic flow in the parking lot and the vehicle movement characteristics, and providing a reference for parking lot managers to take relevant control measures. To achieve the above purpose, the technical solution adopted by the present invention is:

[0005] A simulation-based method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot includes the following steps:

[0006] Step 1: Obtain the floor plan of the comprehensive passenger transport hub parking lot to be constructed, and determine whether it meets the construction requirements, which include that the parking lot is rectangular in shape, has a passenger pick-up area, and has vertical parking spaces;

[0007] Step 2: Identify the inner passages and parking spaces based on the parking lot plan, and rasterize the passages and parking spaces through the simulation system to distinguish between the passenger receiving area and the non-passenger receiving area;

[0008] Step 3: Generate the number of vehicles entering the venue using Poisson probability distribution, and distribute the purpose of vehicle entry in a certain proportion;

[0009] Step 4: Generate vehicle movement logic within the field and handle conflicts between moving vehicles; when a blockage occurs that the vehicle cannot resolve on its own, proceed to step 5;

[0010] Among them, conflicts include conflicts overtaking parked vehicles, conflicts over turning at intersections, conflicts over entering parking spaces, conflicts over leaving parking spaces, and conflicts over reallocation of parking areas;

[0011] Step 5: Evaluate and analyze the simulation system and propose methods to improve parking lot management.

[0012] Preferably, the Poisson probability distribution in step 3 is as follows:

[0013]

[0014] Where k = 0, 1, 2, 3, ...;

[0015] P(X=k) - the probability that K vehicles appear in one simulation second.

[0016] Preferably, the purpose of entering the venue in step 3 includes:

[0017] For parking in non-reception area parking spaces, the proportion of entry purpose is P1;

[0018] For non-passenger reception area aisle parking, the proportion of entry purpose is P2;

[0019] Parking in the passenger reception area has a purpose ratio of P3;

[0020] For parking in the pick-up area, the proportion of entry purpose is P4;

[0021] Among them, P1+P2+P3+P4=1.

[0022] Preferably, the vehicle movement logic in step 4 specifically includes the following steps: for a single vehicle, the program allocates its parking position according to its purpose of entering the site, calculates the shortest path as its movement path, and sets its movement rules according to the logic of driving on the right and giving way to vehicles going straight before turning.

[0023] Preferably, handling conflicts between moving vehicles specifically includes the following steps:

[0024] When encountering a conflict with overtaking a stopped vehicle, the vehicle needs to stop behind the stopped vehicle and wait until there is no car in the opposite lane that will interfere with the overtaking behavior before overtaking;

[0025] When encountering a turning conflict at an intersection, no vehicle can be in the turning path before the turn is completed, and vehicles that are about to go straight through the intersection must stop and wait until the turning vehicle leaves the turning path;

[0026] When encountering a parking space entry conflict, the vehicle behind should wait at a position no less than a safe distance until the vehicle enters the parking space;

[0027] When encountering a parking space conflict, the vehicle behind should wait at a distance no less than the safe distance until the vehicle moves normally;

[0028] When encountering a parking area reallocation conflict, find a parking space in the empty area that has the shortest distance for the vehicle to move and meets the purpose of entry based on the function in the simulation system, allocate the parking space to the vehicle, change the vehicle's destination and move it there;

[0029] If the allocated parking space is occupied again, the function is called again to search for a closer parking space as its new target parking space until the vehicle enters the parking space.

[0030] Preferably, step 5 specifically includes the following steps:

[0031] Calculate the threshold value within the venue under different occupancy rates and vehicle entry purpose ratios;

[0032] The occupancy rate refers to the ratio of parking spaces that have already been occupied by vehicles to the total number of parking spaces when the system is started;

[0033] The threshold refers to the maximum number of cars existing simultaneously in the parking lot minus the number of cars originally occupied when a congestion occurs in the parking lot that the vehicles cannot resolve by themselves or the parking spaces are all full. The experiment is conducted multiple times and the maximum number recorded is taken as the threshold.

[0034] Preferably, the gridding in step 2 specifically includes the following steps: each channel is gridded into squares with sides of half the length of a small car, redundant areas that are not large enough to be divided into one grid are omitted, and the parking space is divided into two grids.

[0035] Preferably, the pick-up area in step 2 refers to the area formed by the adjacent passage of the designated pick-up point in the venue and the two rows of parking spaces adjacent to the pick-up point, and the non-pick-up area refers to the area outside the pick-up area.

[0036] Compared with the prior art, the advantages of the present invention are:

[0037] Taking any parking lot that needs to be studied as the research object, a gridded parking lot is established. On the premise of automatically identifying any parking lot and gridding it, this method sets up a variety of typical conflicts and resolves them, and gives different entry purposes to the vehicles entering the parking lot. The actual movement of vehicle traffic flow in the parking lot and the vehicle movement characteristics are obtained, providing a reference for parking lot managers to take relevant control measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the impact assessment method of conflict behaviors in parking lots of comprehensive passenger transport hubs based on simulation;

[0039] Figure 2 This is an example of a parking lot.

[0040] Figure 3 To identify parking lot floor plans using Python program;

[0041] Figure 4 A two-dimensional array for storing parking spaces and lanes. DETAILED DESCRIPTION

[0042] The following will be described in more detail with reference to the schematic diagram of the present invention, which shows the preferred embodiment of the present invention. It should be understood that those skilled in the art can modify the present invention described herein and still achieve the beneficial effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art and not as a limitation of the present invention.

[0043] The simulation-based conflict behavior impact assessment method in a comprehensive passenger transport hub parking lot includes the following steps:

[0044] Step 1: Obtain the floor plan of the parking lot to be constructed and determine whether it meets the construction requirements.

[0045] First, obtain the floor plan of the parking lot to be constructed. CAD drawings are preferred, and overhead photos can also be used. Then determine whether the parking lot meets the modeling requirements, that is, whether it meets:

[0046] 1) The parking lot is rectangular in shape;

[0047] 2) Periodic parking and road design;

[0048] 3) The parking spaces are all placed in the same direction;

[0049] 4) The road completely surrounds the parking space.

[0050] If the above requirements are met, the parking lot is considered to meet the modeling requirements and modeling operations can be performed.

[0051] Step 2: Based on the Python program, identify the parking lot plan, distinguish between roads and parking spaces, rasterize the parking lot based on vehicle size, and distinguish between the pick-up area and the non-pick-up area.

[0052] The Python program is used to read and identify the parking lot plan, distinguish between roads and parking spaces, and use a small car as the reference vehicle to obtain its length. On any road, the length of the grid is parallel to the direction of vehicle travel, the length is equal to the length of the reference vehicle, and the width of the grid is equal to the width of the road.

[0053] Grids are divided from the starting point to the end point of each road, and the remaining small areas that do not meet the grid standards are discarded. Since the intersection is composed of two pairs of perpendicular roads, a square-like area is generated at the intersection. This square area is divided into four grids, and each parking space is also divided into a grid.

[0054] Each grid is placed into a two-dimensional array according to its position, with the upper left grid as (0,0) (parking lot entrance) and the lower right grid as (M, N) (M, N are the maximum length of the grid - 1 and the maximum width of the grid - 1) (parking lot exit). At the same time, with certain attributes, that is, the lane grid is counted as 0 and the parking space grid is counted as 1, and the horizontal and vertical coordinates of the pick-up area are recorded.

[0055] Define the pick-up area and non-pick-up area. The pick-up area refers to the area consisting of the adjacent passageway of the designated pick-up point in the venue and the two rows of parking spaces adjacent to the pick-up point. The non-pick-up area refers to the area outside the pick-up area.

[0056] Step 3: Generate new vehicles entering the parking lot at the entrance in each simulation second using Poisson probability distribution, and assign a certain proportion of them to the purpose of entering the parking lot. All of the above are completed by Python program.

[0057] The Poisson probability distribution is as follows:

[0058]

[0059] Where k = 0, 1, 2, 3, ...;

[0060] P(X=k) - the probability of K vehicles appearing in one simulation second, where the recommended value of λ is 1 / 100.

[0061] k is the number of vehicles that appear, and its value is a non-negative integer. X represents the number of vehicles that appear in one simulation second, and is a random variable.

[0062] This probability distribution is used to simulate the probability of a new vehicle appearing at the parking lot entrance within each simulation second. The value of λ can be changed according to the actual situation.

[0063] This simulation system (Python program) is mainly designed for the following admission purposes:

[0064] 1) When the vehicle enters the parking lot for parking in a non-passenger parking space, its entry purpose ratio is P1.

[0065] The system will randomly find an empty parking space grid and use the coordinates of this grid as the destination of the vehicle. The vehicle will move into the parking space according to a certain logic.

[0066] If the parking space is found to be occupied when the vehicle moves near it, a parking space reallocation conflict will occur and the vehicle will regain a new empty parking space.

[0067] This process is repeated until the vehicle is successfully parked in the parking space.

[0068] 2) When the vehicle enters the parking lot for parking in a channel other than the passenger reception area, the proportion of the vehicle entering the parking lot is P2.

[0069] The system will randomly find an empty lane grid in the pick-up area and use the coordinates of this grid as the destination of the vehicle. When the vehicle reaches the corresponding position, it will stop directly and complete temporary parking.

[0070] 3) When the vehicle enters the parking lot for parking in the passenger pick-up area, its entry purpose ratio is P4.

[0071] The vehicle will look for the parking space closest to the pick-up point as its target parking space.

[0072] If the parking space is found to be occupied when the vehicle moves to the vicinity of the parking space, a parking space reallocation conflict will occur, and the vehicle will search for a parking space closer to the pick-up point as its target parking space.

[0073] This process is repeated until the vehicle is successfully parked in the parking space and the waiting operation is performed. When the guest arrives, the vehicle leaves the parking space and drives to the pick-up point to pick up the guest.

[0074] 4) When the vehicle enters the parking lot for parking in the passenger pick-up area, its entry purpose ratio is P3.

[0075] The vehicle will go directly to the pick-up point for temporary parking. If it is found that temporary parking is no longer possible at the pick-up point when moving near the pick-up point, a temporary parking relocation conflict will occur and the vehicle will start to execute the parking function near the pick-up point.

[0076] Among them, P1+P2+P3+P4=1.

[0077] According to the field survey data of the P2 parking lot of Nanjing South Railway Station, the probability of random parking in the lot (P1) is 50%, the probability of random temporary parking in the lot (P2) is 10%, the probability of temporary parking near the pick-up point (P3) is 33%, and the probability of parking near the pick-up point (P4) is 7%.

[0078] The above probabilities can be changed according to actual conditions to suit the characteristics of different parking lots.

[0079] Step 4: Generate the vehicle movement logic within the field based on the Python program and handle conflicts between moving vehicles.

[0080] The vehicle movement logic is as follows:

[0081] Vehicle motion logic mainly refers to the way a single vehicle moves, without considering the interaction between the vehicle and its destination or other vehicles.

[0082] When a vehicle appears at the entrance, it will automatically obtain a number to distinguish it from other vehicles, obtain the purpose of entry, obtain the vehicle's destination, and call the start function to start movement.

[0083] When the vehicle is on the road, it reads the possible moving direction of the road and combines it with the modulation of the shortest path function to determine the next direction of movement, allowing the vehicle to reach its destination via the shortest path.

[0084] Vehicles may enter a parking space only where the width of the parking space meets the road.

[0085] At the same time, based on the car-following model, the optimal movement speed of the vehicle is obtained:

[0086] Among them, the car-following model is:

[0087] X1(t+T)=λ[X0(t)-X1(t)]+λL

[0088] Where, X0(t) - the position of the preceding vehicle at time t;

[0089] X1(t) - the position of the vehicle at time t;

[0090] λ - reaction sensitivity coefficient;

[0091] L - Headway in blocked conditions.

[0092] The response to the following vehicle generally refers to acceleration and deceleration. Therefore, the optimal motion speed model of the vehicle is obtained by differentiating the above equation:

[0093] v1(t+T)=λ[v0(t)-v1(t)]

[0094] In the formula, v0(t) is the speed of the preceding vehicle at time t;

[0095] v1(t) – the speed of the vehicle at time t;

[0096] v1(t+T) - the speed of the vehicle after a delay of T time.

[0097] Set the appropriate λ value according to the actual situation to make the vehicle speed reach the most reasonable state.

[0098] After generating the vehicle motion logic, this simulation system mainly considers and handles the following vehicle conflicts:

[0099] 1) Conflicts with overtaking parked vehicles

[0100] Overtaking parked vehicle conflict refers to a vehicle temporarily parked on the road, where the vehicles behind cannot pass normally and can only occupy the opposite lane, causing a conflict.

[0101] When encountering this conflict, the vehicle needs to stop behind the temporarily parked vehicle and wait until there are no vehicles in the opposite lane that will interfere with the overtaking behavior before overtaking.

[0102] 2) Conflicts at intersections

[0103] An intersection turning conflict refers to a spatial conflict between a vehicle about to make a turn and a vehicle going straight.

[0104] For vehicles that are turning at an intersection, there must not be any other vehicles in the turning path before the turn is completed, and vehicles that are about to enter the turning path must stop and wait until the turning vehicle leaves the turning path;

[0105] 3) Conflicts when entering parking spaces

[0106] Parking space conflict refers to when a vehicle is about to enter a parking space, it blocks the normal movement of the vehicle behind it, causing a conflict. The vehicle behind it should wait at a position not less than a safe distance until the vehicle enters the parking space.

[0107] 4) Conflicts with parking spaces

[0108] Parking conflict refers to the situation where a vehicle is about to leave a parking space and blocks the normal movement of the vehicle behind it, causing a conflict. The vehicle behind should wait at a position no less than a safe distance until the vehicle moves normally.

[0109] 5) Parking area reallocation conflicts

[0110] Parking area reallocation conflict means that when a vehicle is about to enter a parking space, it finds that the parking space is already occupied, so it needs to find a closer parking space as its new target parking space, resulting in a conflict.

[0111] The vehicle will look for an empty parking space closest to the vehicle's current location, that is, a parking space with the shortest required movement distance, allocate the parking space to the vehicle, change the vehicle's destination, and move there.

[0112] If the assigned parking space is occupied again, then a closer parking space is searched again as its new target parking space until the vehicle successfully enters the parking space.

[0113] Step 5: Evaluate and analyze the simulation system and propose methods to improve parking lot management.

[0114] The evaluation of this simulation system is mainly through the control variable method, that is, only changing the occupancy rate in the parking lot or only changing the proportion of vehicles entering the parking lot to conduct a large number of situation simulations to obtain simulation results, and compare them with the actual results to evaluate the rationality of the simulation system.

[0115] Specifically: Calculate the threshold within the venue by only changing the occupancy rate or the proportion of vehicle entry purposes.

[0116] The occupancy rate refers to the ratio of the number of occupied parking spaces in the parking lot to the total number of parking spaces before the first car enters the parking lot entrance. These occupied parking spaces will no longer change until the end of the simulation program, and they will always remain occupied to simulate the impact of long-term parking vehicles.

[0117] The threshold refers to the maximum number of vehicles existing simultaneously in the parking lot minus the number of original occupied vehicles when a congestion occurs in the parking lot that cannot be resolved by the vehicles themselves. The experiment is carried out multiple times and the maximum number recorded is taken as the threshold.

[0118] The relationship between the threshold and the occupancy rate is obtained. If the occupancy rate is high and the threshold is also high, then it can be considered that this is the optimal occupancy rate of the parking lot.

[0119] At the same time, the actual threshold of the parking lot at the same occupancy rate is obtained through field investigation and compared with the threshold obtained by simulation. If the threshold obtained by simulation is significantly larger than the actual threshold, it can be considered that the conflict resolution logic of the simulation system has played a beneficial role.

[0120] Taking Nanjing South Railway Station P2 parking lot as an example, the parking lot has a total of 261 parking spaces:

[0121] Step 1: Get the floor plan of Nanjing South Railway Station P2 parking lot, such as Figure 2 As shown, it is determined that it meets the construction requirements. Figure 2 The picture shows the parking lot plan. The yellow area, i.e., area A, is the parking space belonging to the pick-up area.

[0122] Step 2: Use Python program to identify the parking lot floor plan, that is Figure 3 , distinguish parking spaces and lanes and rasterize them into a two-dimensional array, such as Figure 4 The upper left grid is the entrance, and the lower right grid is the exit.

[0123] Step 3: Figure 4 The two-dimensional array shown is the processing object to start the simulation, and the Poisson probability distribution is used to determine whether there is a vehicle at the entrance within this simulation second. At the same time, all other vehicles move once according to their own logic, including moving forward one grid, stopping in a grid, and other operations. After all vehicles have completed their own operations, this simulation second ends and the next simulation second begins.

[0124] Repeat step 3 until a congestion occurs that the vehicles cannot resolve by themselves. Record the maximum number of vehicles existing simultaneously in the parking lot minus the number of vehicles originally occupied. Perform the experiment multiple times and take the maximum number recorded as the threshold.

[0125] Table 1 Simulation results

[0126] Occupancy 90％ 80％ 70％ 60％ 50％ Threshold 57 68 126 84 79

[0127] Table 2 Actual results

[0128] Occupancy 90％ 80％ 70％ 60％ 50％ Threshold 43 50 106 73 71

[0129] According to the results of the above two tables, it can be considered that the conflict resolution logic of the simulation system plays a beneficial role.

[0130] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A simulation-based method for evaluating the impact of conflict behaviors in parking lots at comprehensive passenger transport hubs. It is characterized in that The following steps are involved: Step 1: Obtain the floor plan of the comprehensive passenger transport hub parking lot to be constructed, and determine whether it meets the construction requirements, which include that the parking lot is rectangular in shape, has a passenger pick-up area, and has vertical parking spaces; Step 2: Identify the inner passages and parking spaces based on the parking lot plan, and rasterize the passages and parking spaces through the simulation system to distinguish between the passenger receiving area and the non-passenger receiving area; Step 3: Generate the number of vehicles entering the venue using Poisson probability distribution, and distribute the purpose of vehicle entry in a certain proportion; Among them, the Poisson probability distribution is as follows: Where k = 0, 1, 2, 3, ...; P(X=k) - the probability that K vehicles appear in one simulation second; Step 4: Generate the vehicle movement logic in the field and handle the conflicts between moving vehicles; when a blockage occurs that the vehicle cannot resolve by itself, proceed to step 5; Among them, conflicts include conflicts overtaking parked vehicles, conflicts over turning at intersections, conflicts over entering parking spaces, conflicts over leaving parking spaces, and conflicts over reallocation of parking areas; The processing of the conflict between moving vehicles specifically includes the following steps: When encountering a conflict with overtaking a stopped vehicle, the vehicle needs to stop behind the stopped vehicle and wait until there is no car in the opposite lane that will interfere with the overtaking behavior before overtaking; When encountering a turning conflict at an intersection, no vehicle can be in the turning path before the turn is completed, and vehicles that are about to go straight through the intersection must stop and wait until the turning vehicle leaves the turning path; When encountering a parking space entry conflict, the vehicle behind should wait at a position no less than a safe distance until the vehicle enters the parking space; When encountering a parking space conflict, the vehicle behind should wait at a distance no less than the safe distance until the vehicle moves normally; When encountering a parking area reallocation conflict, find a parking space in the empty area that has the shortest distance for the vehicle to move and meets the purpose of entry based on the function in the simulation system, allocate the parking space to the vehicle, change the vehicle's destination and move it there; If the allocated parking space is occupied again, the function is called again to find a closer parking space as its new target parking space until the vehicle enters the parking space; Step 5: Evaluate and analyze the simulation system and propose methods to improve parking lot management.

2. The method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation according to claim 1, It is characterized in that The purpose of entering the market in step 3 includes: The proportion of parking spaces in non-reception areas for the purpose of entry is P 1 ; The proportion of parking in the non-passenger receiving area is P 2 ; The proportion of parking in the reception area is P 3 ; The proportion of parking spaces in the reception area for the purpose of entry is P 4 ; Among them, P 1 +P 2 +P 3 +P 4 =1.

3. The method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation according to claim 1, It is characterized in that The vehicle movement logic in step 4 specifically includes the following steps: for each vehicle, the program assigns its parking position according to its purpose of entering the site, calculates the shortest path as its movement path, and sets its movement rules according to the logic of driving on the right and giving way to vehicles going straight when turning.

4. The method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation according to claim 1, It is characterized in that Step 5 specifically includes the following steps: Calculate the threshold value within the venue under different occupancy rates and vehicle entry purpose ratios; The occupancy rate refers to the ratio of parking spaces that have already been occupied by vehicles to the total number of parking spaces when the system is started; The threshold refers to the maximum number of cars existing simultaneously in the parking lot minus the number of cars originally occupied when a congestion occurs in the parking lot that the vehicles cannot resolve by themselves or the parking spaces are all full. The experiment is conducted multiple times and the maximum number recorded is taken as the threshold.

5. The method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation according to claim 1, It is characterized in that The gridding in step 2 specifically includes the following steps: each channel is gridded into squares with sides of half the length of a small car, redundant areas that are not enough to be divided into one grid are omitted, and the parking space is divided into two grids.

6. The method for evaluating the impact of conflict behaviors in a comprehensive passenger transport hub parking lot based on simulation according to claim 1, It is characterized in that The pick-up area in step 2 refers to the area consisting of the adjacent passage of the designated pick-up point in the venue and the two rows of parking spaces adjacent to the pick-up point, and the non-pick-up area refers to the area outside the pick-up area.

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