Cooperative control method for vehicle merging trajectories in the merging zone of a highway under mixed traffic flow

Abstract

This invention relates to the field of vehicle merging technology under mixed traffic flow, and discloses a method for coordinated control of vehicle merging trajectories in highway merging zones under mixed traffic flow. The method includes dividing the highway merging zone into a control zone and a merging zone; determining feasible merging gaps on the main road based on vehicle types and states before and after gaps within the control zone, as well as the range of feasible gap adjustments for safety distances and different vehicle gaps; establishing a trajectory optimization model with the goal of minimizing vehicle operating energy consumption based on the feasible merging gaps on the main road and the vehicle arrival time at the end of the control zone; using the trajectory optimization model to traverse all possible merging gaps on the main road, and selecting the feasible gap with the lowest energy consumption as the merging gap for coordinated vehicle trajectory optimization control. This invention achieves coordinated control of merging sequence and vehicle trajectory planning during vehicle merging in merging zones, improving operational efficiency and reducing overall energy consumption.

Description

Technical Field

[0001] This invention relates to the field of vehicle merging technology under mixed traffic flow, and specifically to a method for collaborative control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow. Background Technology

[0002] Merging areas at highway entrance ramps are often critical bottlenecks in traffic flow, causing not only severe congestion but also potentially leading to upstream spread of congestion and triggering new accidents. Early solutions relied primarily on traditional ramp signal control and traffic flow control strategies, which typically assume all vehicles will uniformly adhere to the same control measures. However, this ignores subtle variations in traffic flow, resulting in limited improvement. Intelligent Connected Vehicles (ICVs) technology is considered an effective way to alleviate these problems. However, ICVs and traditional human-driven vehicles (HDVs) will coexist for a considerable period, forming mixed traffic flows. Therefore, research on highway entrance ramp merging strategies for this mixed traffic flow environment is particularly important.

[0003] The existing vehicle merging schemes under mixed traffic flow mainly have the following problems:

[0004] (1) Previous studies on merging at highway entrance ramps under the background of intelligent connected vehicles have mainly focused on the ICV merging trajectory method under the background of pure connected vehicles. They lacked coordinated control of vehicles on ramps and main roads, and lacked coordinated consideration of the dynamic interaction between merging sequence selection and vehicle trajectory planning.

[0005] (2) Previous studies on merging control of mixed traffic flow mainly focused on static optimization of vehicle trajectories based on the gap between vehicles merging from ramps into main roads, without considering the dynamic interaction between merging sequence selection and vehicle trajectory planning.

[0006] (3) Previous vehicle merging methods based on optimization of mixed traffic flow mostly aimed to ensure that vehicles on ramps could merge in accordance with a specified merging sequence, and lacked consideration of the impact of vehicle acceleration changes on vehicle energy consumption. Summary of the Invention

[0007] To address the aforementioned shortcomings in the prior art, this invention provides a method for collaborative control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0009] A method for cooperative control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow includes the following steps:

[0010] The merging zone of the expressway is divided into a control zone and a merging zone. Based on the types and states of vehicles before and after the gap in the control zone, as well as the range of coordinated adjustment of safety distances and feasible gaps between different vehicle gaps, the feasible gap for the main road to merge is determined.

[0011] Based on the feasible merging gaps on the main road and the time it takes for a vehicle to reach the end of the control area, a trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption. The trajectory optimization model is then used to traverse all possible merging gaps on the main road, and the feasible gap with the minimum energy consumption is selected as the merging gap for collaborative optimization control of vehicle trajectory.

[0012] The present invention has the following beneficial effects:

[0013] (1) Under mixed traffic flow conditions, the existing mainline gap status passively selects the merging sequence and then performs trajectory planning based on the first-in-first-out principle, lacking active control over the mainline gap; This invention proposes a possible merging gap search method that considers vehicle characteristics, which not only determines the existing feasible gaps that can meet the requirements for safe merging, but also calibrates the potential feasible gaps that can meet the requirements for safe merging by adjusting them, thereby determining the possible merging gaps.

[0014] (2) Most methods for controlling vehicle merging in merging zones on highways focus on ensuring that vehicles on ramps merge according to a specified merging sequence, but lack consideration for the impact of vehicle acceleration changes on vehicle energy consumption. To address this, this invention considers the interactive relationship between merging sequence and vehicle trajectory planning. While ensuring the safe and efficient merging of ramp vehicles into the main line, it aims to minimize vehicle energy consumption by planning the trajectories and adjusting the gaps for ramp vehicles and all vehicles before and after possible merging gaps. Finally, it selects the feasible gap with the lowest energy consumption as the merging gap, achieving coordinated control of merging sequence and vehicle trajectory planning during merging in merging zones, thus improving operational efficiency and reducing overall energy consumption. Attached Figure Description

[0015] Figure 1 A schematic diagram of a collaborative control method for vehicle merging trajectories in the merging zone of a highway under mixed traffic flow;

[0016] Figure 2 A schematic diagram illustrating a scenario where vehicles merge at a highway entrance ramp to accommodate mixed traffic flows.

[0017] Figure 3 This is a flowchart illustrating the feasible gap determination method;

[0018] Figure 4 A schematic diagram illustrating the process of optimizing vehicle merging sequence and trajectory planning within the control area;

[0019] Figure 5 For the ramp ICV penetration rate P without a control strategy ρ =0.6 and road density P I A schematic diagram of the test results for a value of 0.4;

[0020] Figure 6 For the ramp ICV penetration rate P without a control strategy ρ =0.6 and road density P I A schematic diagram of the test results for a value of 0.8;

[0021] Figure 7 For the ramp ICV penetration rate P without a control strategy ρ =0.9 and road density P I A schematic diagram of the test results for a value of 0.4;

[0022] Figure 8 For the ramp ICV penetration rate P without a control strategy ρ =0.9 and road density P I A schematic diagram of the test results for a value of 0.8;

[0023] Figure 9 When implementing a vehicle dynamic cooperative merging control strategy, the ramp ICV penetration rate P ρ =0.6 and road density P I A schematic diagram of the test results for a value of 0.4;

[0024] Figure 10 When implementing a vehicle dynamic cooperative merging control strategy, the ramp ICV penetration rate P ρ =0.6 and road density P I A schematic diagram of the test results for a value of 0.8;

[0025] Figure 11 When implementing a vehicle dynamic cooperative merging control strategy, the ramp ICV penetration rate P ρ =0.9 and road density P I A schematic diagram of the test results for a value of 0.4;

[0026] Figure 12 When implementing a vehicle dynamic cooperative merging control strategy, the ramp ICV penetration rate P ρ =0.9 and road density P I A schematic diagram of the test results for a value of 0.8. Detailed Implementation

[0027] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0028] This invention proposes a collaborative control method for vehicle merging trajectories in the merging zone of a highway under mixed traffic flow. First, considering the vehicle operating characteristics of ICVs (Incoming Traffic Vehicles) and HDVs (High-Depth Traffic Vehicles) in the control area, all possible merging gaps on the main road are determined. Then, considering the interaction between the merging sequence and vehicle trajectory planning, a trajectory optimization model is established with the goal of minimizing vehicle energy consumption, and the merging gaps on the ramps and main roads are planned. Finally, using the established trajectory optimization model, all possible merging gaps on the main road are traversed, and the feasible gap with the lowest energy consumption is selected as the merging gap, thereby achieving collaborative optimization control of vehicles with minimum energy consumption.

[0029] Reference Figure 1 and Figure 4 The present invention provides a method for cooperative control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow, comprising the following steps S1 to S2:

[0030] S1. Divide the merging area of ​​the expressway into a control zone and a merging zone. Determine the feasible gap for the main road to merge based on the types and states of vehicles before and after the gap in the control zone, as well as the range of coordinated adjustment of safety distance and feasible gaps between different vehicles.

[0031] In an optional embodiment of the present invention, the application scenario is a highway merging zone under intelligent connected mixed traffic flow composed of ICV and HDV. For example... Figure 3 As shown, the ramp connects to the mainline via a parallel acceleration lane. During vehicle operation, the ICV (Intelligent Vehicle Vehicle) can automatically send commands to the vehicle in real time through roadside units and its own sensor information, such as vehicle speed, acceleration, and position. The ICV, on the other hand, guides the vehicle based on information about the vehicle ahead, adjusting its state, but there is a possibility of it not obeying guidance. This paper divides the merging zone into an upstream control zone and a vehicle merging zone. To ensure that ramp vehicles can merge into the mainline efficiently, with low energy consumption and safety, a merging gap is searched in the upstream control zone, and the merging gap is selected based on the principle of minimum energy consumption. The selected ramp vehicles and the vehicles before and after the expected merging gap are called a cooperative vehicle group. Considering the uncertainty of HDV (High-Density Vehicle), real-time vehicle trajectory planning or guidance is performed on the ramp vehicles and the vehicles before and after the expected merging gap on the mainline, enabling ramp vehicles to merge into the mainline safely and efficiently in the merging zone.

[0032] This embodiment first assumes:

[0033] (1) Only consider the merging of the rightmost lane of the highway ramp, and the ramp has only one lane, such as Figure 2 As shown.

[0034] (2) The vehicles in the merging zone consist of ICVs and HDVs. The IDM car-following model is used between HDVs, the ACC car-following model is used between ICVs and HDVs, and the CACC car-following model is used between ICVs. It is assumed that the ICVs can obtain information such as the speed, acceleration, and position of surrounding vehicles in real time and can execute control commands without delay. The HDVs use the IDM car-following model. Under this condition, the driving status of the HDVs cannot be completely controlled, but their trajectories are predictable in a short period of time (such as within a few seconds).

[0035] (3) Only the longitudinal trajectory is considered. It is assumed that the ICV and HDV meet the lane-changing conditions and complete the lane-changing instantaneously. The lane-changing model adopts the LC2013 model.

[0036] To ensure the safe and efficient merging of ramp vehicles into the mainline within the merging zone, this embodiment requires advance searching of lane-changing gaps for ramp vehicles merging into the mainline within the upstream control area, thereby determining the merging sequence and vehicle trajectories. When determining the mainline merging gap, if only existing gaps that meet the merging distance requirements are selected, feasible gaps created through coordinated vehicle control may be overlooked. Therefore, this embodiment proposes a feasible merging gap search method. Based on vehicle status and considering safety distances, it analyzes the feasible gap adjustment range between different vehicle gaps to determine feasible merging gaps that meet safe lane-changing conditions. This includes vehicle gaps that meet safety distances under the current conditions and potential vehicle gaps that meet safety distances after vehicle control. Here, the vehicle gap selected by ramp vehicles is defined as i∈I. col I col Let I be the set of all vehicle gaps on the main road from the initial to the end position of the control zone, and let I be the set of feasible gaps for potential main road merging that meet the safe lane-changing conditions. F Let the initial

[0037] This embodiment determines the feasible merging gap of the main road based on the vehicle types and states before and after the gap within the control zone, as well as the range of coordinated adjustment of safety distances and feasible gaps between different vehicle gaps, including:

[0038] Starting from the first vehicle on the main line of the main road control zone, calculate the distance between vehicles before and after the vehicles in the gaps of the main road control zone;

[0039] Determine whether the distance between vehicles before and after the gap is greater than or equal to the minimum safe gap; if so, merge the gap into a feasible gap as a main road; otherwise, adjust the gap before the end of the main road control area according to the type of vehicles before and after the gap to meet the requirement of a feasible gap.

[0040] Among them, a feasible gap is defined as adjusting the vehicle type before and after the gap before the end point of the main road control area to achieve the desired gap, including:

[0041] When both the preceding and following vehicles are intelligent connected vehicles, the following vehicle decelerates at a comfortable deceleration while the preceding vehicle maintains a constant speed. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the preceding vehicle accelerates at its maximum safe acceleration while the following vehicle maintains a constant speed. The same process is repeated, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the following vehicle decelerates at a comfortable deceleration while the preceding vehicle accelerates at its maximum safe acceleration. The same process is repeated, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the clearance is deemed infeasible.

[0042] When the vehicles in front and behind are intelligent connected vehicles and manually driven vehicles, the following vehicle will decelerate at a comfortable deceleration and the preceding vehicle will drive at a constant speed. It will be determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control area. If so, the adjusted clearance will be merged into the feasible clearance as a main road; otherwise, the clearance will be an infeasible clearance.

[0043] When the vehicles in front and behind are manually driven vehicles and intelligent connected vehicles, the vehicle in front is accelerated with the maximum safe acceleration and the vehicle behind is driven at a constant speed. It is then determined whether the minimum safe clearance is met when the vehicle in front reaches the end point of the main road control area. If so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the clearance is an infeasible clearance.

[0044] When both the preceding and following vehicles are manually driven, the following vehicle is decelerated at a comfortable deceleration while the preceding vehicle is driven at a constant speed. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the clearance is considered infeasible.

[0045] In this embodiment, calculations are first performed sequentially from the first vehicle on the mainline of the main road control area backwards to determine whether the gap can be adjusted to a feasible gap before the end of the main road control area. The feasible gap is categorized as greater than the minimum safe merging distance S. safe The gap, and the gap that can be adjusted to a feasible gap before the end of the main road control area after adjustment. Where S safe The calculation method is as follows:

[0046] g min_m =s0+τ·v mer +lv

[0047] S safe=2·g min_m

[0048] Where g min_m v represents the minimum safe following distance between a ramp vehicle and the vehicles in front and behind it when merging into the main road at the merging zone. mer s represents the inflow speed at the merge point. o τ is the vehicle stationary clearance, τ is the minimum safe headway, and lv is the vehicle length.

[0049] Then, calculate the distance ΔX between vehicles A and B at time k within the main road control zone, based on the gap i between them. i,AB,k If it is greater than the minimum safe merging distance S safe If so, then the gap i is determined to be a feasible gap, I F =I F ∪i, corresponding to:

[0050] ΔX i,AB,k =X i,A,k -X i,B,k ≥S safe

[0051] If the requirements are not met, determine whether the gap can be adjusted before the end of the control area to achieve the desired result; if so, consider it a feasible gap. If it is, add the gap i to the feasible gap set I. F middle, I F =I F ∪i.

[0052] Reference Figure 2 The following are the methods for determining whether the clearance between vehicles on the main road is feasible and for its specific adjustment:

[0053] (1) Rear vehicle - front vehicle is ICV-ICV: First take method 1. If a feasible gap cannot be generated, take method 2. If a feasible gap still cannot be generated, take method 3. If no feasible gap can be generated, the gap is considered to be an infeasible gap.

[0054] (2) Rear vehicle - front vehicle is ICV-HDV: Method 1 is adopted. If a feasible gap cannot be generated, the gap is considered infeasible.

[0055] (3) The rear vehicle to the front vehicle is HDV-ICV: Method 2 is adopted. If a feasible gap cannot be generated, the gap is considered to be infeasible.

[0056] (4) Rear vehicle - front vehicle is HDV-HDV: If method 1 is adopted, and a feasible gap cannot be generated, the gap is considered to be infeasible.

[0057] In this embodiment, method 1 decelerates the following vehicle at a comfortable deceleration and keeps the preceding vehicle moving at a constant speed, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone, including:

[0058] Based on the speed of the following vehicle and the time it takes for the preceding vehicle to reach the end point of the main road control zone at a constant speed, calculate the speed of the following vehicle as it continues to decelerate until the end point of the main road control zone.

[0059] Determine whether the speed of the following vehicle as it decelerates until the end of the main road control zone is less than the minimum speed limit; if so, calculate the position of the following vehicle as it decelerates until the end of the main road control zone; otherwise, calculate the position of the following vehicle as it decelerates first and then travels at a constant speed during the control zone's operating segment.

[0060] Calculate the distance between vehicles when the vehicle in front reaches the end of the control zone based on the position of the vehicle behind, and determine whether the distance between vehicles meets the minimum safe clearance; if so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the adjustment fails.

[0061] In this embodiment, when the following vehicle decelerates at a comfortable deceleration and the preceding vehicle travels at a constant speed, it is determined whether the minimum safe clearance is met when the preceding vehicle reaches the end of the main road control zone. Let X be the position of the preceding vehicle A at a constant speed to the end point of the control zone in the i-th clearance. Col_end The duration is The following car B decelerates at a comfortable deceleration. The speed at any given moment can be expressed as:

[0062]

[0063] Where t k v is the timestamp corresponding to the k-th time step. i,B (t k Let ) represent the gap after which car B is at t. k Hourly velocity, a dec For comfortable vehicle deceleration, v min This is the minimum speed limit. At this point, if vehicle B continues to decelerate during the i-th gap until the end of the main road control zone, the corresponding speed is... When it is less than v min At that time, vehicle B continued to decelerate uniformly until the end of the control zone. Vehicle B was within the specified time... Corresponding position Represented as:

[0064]

[0065] Where X i,B (t k Let t be the position of car B after the i-th gap at time t0.

[0066] Otherwise, if the vehicle's speed reaches the minimum speed limit before the end of the control zone, the following vehicle B will first decelerate and then maintain a constant speed. The position of the vehicle during its travel within the control zone will be:

[0067]

[0068] When vehicle A reaches the end position of the control zone, calculate Distance between vehicles after a certain time for:

[0069]

[0070] Judging the distance between vehicles Is it greater than the minimum safe merging spacing S? safe If the minimum safe merging spacing is not met, then method 1 is not feasible.

[0071] In this embodiment, method 2 accelerates the preceding vehicle with maximum safe acceleration and keeps the following vehicle moving at a constant speed, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone, including:

[0072] Calculate the speed of the vehicle ahead of the preceding vehicle when it reaches the end point of the main road control zone based on the time it takes for the preceding vehicle to travel at a constant speed from the initial point to the end point of the main road control zone.

[0073] Determine the speed of the vehicle in front, calculate the distance traveled after the vehicle accelerates to its maximum speed, and determine whether the distance traveled is less than the distance between the vehicle in front and the end point of the control zone at the beginning of the gap; if so, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly accelerating to its maximum speed; otherwise, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly decelerating.

[0074] The distance between vehicles in front and behind is calculated based on the time it takes for the preceding vehicle to reach the end point of the control zone. It is then determined whether the distance between vehicles in front and behind meets the minimum safe clearance. If so, the adjusted clearance is merged into the feasible clearance as a main road. Otherwise, the adjustment fails.

[0075] In this embodiment, when the preceding vehicle accelerates at its maximum safe acceleration and the following vehicle travels at a constant speed within the corresponding control gap, it is determined whether the minimum safe merging gap is met before the preceding vehicle reaches the end of the main road control zone. Let the maximum speed at which the preceding vehicle A can accelerate be v. A_max Its corresponding value range is v i,A (t k )≤v A_max ≤v max If the clearance before vehicle A is the used clearance, then the speed of vehicle A must be less than or equal to the speed of the vehicle A_F preceding it. At this point, v A_max =v A_F If the previous gap of the vehicle A in the corresponding control gap is not used, then when the vehicles A and A_F in the i-th gap reach the end of the main road control zone, it is only necessary to meet the minimum headway h of the vehicles traveling. Let the time it takes for the vehicle A_F in the i-th gap to reach the end of the control zone from the initial point at a constant speed be... for:

[0076]

[0077] Where L M This represents the total length of the control area.

[0078] Let the headway T be between the preceding vehicle A and its corresponding preceding vehicle A_F. AA_F During operation within the controlled area, the maximum safe headway must be maintained, i.e., T AA_F ≥h. And the car in front, A, is... speed The calculation formula is:

[0079]

[0080] Where a max Maximum possible acceleration:

[0081] When vehicle A_F reaches the end of the main road control zone, let the speed of the preceding vehicle A be... When its speed is less than v A_max hour Vehicle A accelerates at a constant speed until it reaches the end point of the main road control zone, at the position corresponding to time t2. for:

[0082]

[0083] Otherwise, the car in front, A, accelerates to its maximum speed, v. A_max Then, in a uniform motion, at the position corresponding to time t2 for:

[0084]

[0085] The car in front, A, accelerates to its maximum speed, v. A_max The distance traveled afterward ΔX i,A_v for:

[0086]

[0087] Let L M -X i,A (t k ) represents the position of the preceding vehicle A in the i-th gap at time t. k The distance between the current point and the end point of the control area, where ΔX is... A_v Less than L M -X i,A (t k That is, the car in front A accelerates to v. A_max If the vehicle still hasn't reached the end of the control zone, it will accelerate to v. A_max Then, it continues to travel at a constant speed until it reaches the end point of the control zone. At this point, the car in front, A, continues to accelerate at a constant speed until it reaches v. A_maxThe time t1 for reaching the end point of the control area is:

[0088]

[0089] Otherwise if ΔX A_v Greater than L M -X A (t k The vehicle A in front decelerates uniformly until it reaches the end of the control zone. The time it takes for vehicle A to reach the end of the control zone is then calculated. for:

[0090]

[0091] When vehicle A reaches the end position of the control zone, calculate The time is:

[0092]

[0093] The distance between vehicles at the i-th gap Is it greater than the minimum safe merging spacing S? safe If the minimum safe merging spacing is not met, then method 2 is not feasible.

[0094] In this embodiment, method 3 decelerates the following vehicle at a comfortable deceleration and accelerates the preceding vehicle at a maximum safe acceleration, determining whether the minimum safe clearance is met when the preceding vehicle reaches the main road control zone point, including:

[0095] Calculate the speed of the vehicle ahead of the preceding vehicle when it reaches the end point of the main road control zone based on the time it takes for the preceding vehicle to travel at a constant speed from the initial point to the end point of the main road control zone.

[0096] Determine the speed of the vehicle in front, calculate the distance traveled after the vehicle accelerates to its maximum speed, and determine whether the distance traveled is less than the distance between the vehicle in front and the end point of the control zone at the beginning of the gap; if so, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly accelerating to its maximum speed; otherwise, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly decelerating.

[0097] Calculate the position of the following vehicle based on the time it takes for the preceding vehicle to reach the end point of the control zone;

[0098] Calculate the distance between vehicles in front and behind based on the position of the following vehicle, and determine whether the distance between vehicles in front and behind meets the minimum safe clearance; if so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the adjustment fails.

[0099] In this embodiment, when the following vehicle in the corresponding control gap decelerates at a comfortable deceleration and the preceding vehicle accelerates at the maximum safe acceleration, it is determined whether the minimum safe merging distance is met before the preceding vehicle reaches the end of the main road control zone. Based on method 2, the time for the preceding vehicle A to reach the end of the control zone is calculated. Then, based on method 1, the time interval i of vehicle B is calculated. Location of time This yields the maximum possible vehicle distance ΔX between vehicle A in front and vehicle B behind at the i-th gap. i " , ' AB for:

[0100]

[0101] If ΔX” i,AB Greater than the safety distance S safe If the gap is valid, then the gap is considered a feasible gap; otherwise, method 3 fails.

[0102] S2. Based on the feasible gaps for merging into the main road and the time for vehicles to reach the end of the control area, a trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption. The trajectory optimization model is used to traverse all possible gaps in the main road for merging, and the feasible gap with the minimum energy consumption is selected as the merging gap for collaborative optimization control of vehicle trajectory.

[0103] In an optional embodiment of the present invention, a trajectory optimization model is established based on the feasible merging gaps of the main road and the vehicle's arrival time at the end of the control area, with the goal of minimizing vehicle operating energy consumption. The trajectory optimization model is then used to iterate through all possible merging gaps of the main road, and the feasible gap with the lowest energy consumption is selected as the merging gap for collaborative vehicle trajectory optimization control, including:

[0104] Determine whether the vehicles merging into the ramp are intelligent connected vehicles or manually driven vehicles;

[0105] If the vehicle merging on the ramp is an intelligent connected vehicle, the minimum arrival time of the preceding vehicle on the main road and the vehicle merging on the ramp to the end of the acceleration zone is calculated separately. Based on the feasible merging gaps on the main road, it is determined from front to back whether the minimum arrival time of the vehicle merging on the ramp to the end of the acceleration zone is less than or equal to the minimum arrival time of the preceding vehicle on the main road to the end of the acceleration zone. If so, a trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption. The energy consumption corresponding to the current time slot is determined using the trajectory optimization model, and the feasible gap with the minimum energy consumption is selected as the merging gap for vehicle trajectory collaborative optimization control.

[0106] If the vehicle merging on the ramp is a manually driven vehicle, the time it takes for the vehicle to reach the merging point according to the car-following model is calculated. Then, based on the feasible merging gaps on the main road, the time for the preceding vehicle to reach the merging point in each time slot on the main road is calculated to determine the possible merging time slots for the vehicle merging on the ramp. Finally, the vehicle merging on the ramp follows the preceding vehicle according to the car-following model in the ramp control area, and at the same time, follows the preceding vehicle in the main road time slot in the acceleration area until the merging conditions are met and the vehicle merges.

[0107] Reference Figure 3 This embodiment includes the following collaborative optimization for ICVs merging into the ramp:

[0108] When the merging vehicle on the ramp is an ICV, the corresponding feasible gap i∈I is used. F In this study, a trajectory optimization model is established with the minimum arrival time of the preceding vehicle to the merging point as the benchmark and the goal of minimizing energy consumption. The energy consumption of vehicles before and after the gap, as well as vehicles cooperating with the ramp, merging into the gap is calculated, and then the vehicle with the minimum energy consumption is selected to enter the gap.

[0109] First, set a virtual merging point X in the merging zone. R_vmer This represents the location where vehicle R, merging from the ramp, enters the mainline. This point is not a fixed point for vehicles to merge; rather, it's for the purpose of evaluating the efficiency and energy consumption of the merging sequence. The specific merging point of a vehicle on the ramp is not fixed; it only needs to merge before the end of the merging zone. First, calculate the time when vehicle A, preceding the i-th gap, arrives at the end of the control zone. and corresponding speed Then, the acceleration process from the end of the control zone to the merging point is calculated, along with the minimum arrival time. This yields the minimum arrival time for vehicle A ahead of it in each gap to reach the merging point from the control zone. The travel time of the preceding vehicle A from the end of the main road control zone to the merging point during the i-th gap is calculated into three parts. The first part is the time t for the preceding vehicle A to accelerate to its maximum speed. i,A,acc1 The second part is the time t during which the vehicle travels a certain distance at its maximum constant speed. i,A,acc2 The third part is the time t it takes for the vehicle to decelerate uniformly to the merging velocity at the merging point. i,A,acc3 The calculation method is as follows:

[0110]

[0111]

[0112] In the formula: v max For the maximum speed limit of the vehicle, v m Let a be the merging speed of the vehicles. max For the maximum acceleration, a min This is the maximum deceleration. Considering that the vehicle in front of gap i must satisfy a safe distance h between itself and the vehicle behind it (i.e., the vehicle in front of gap i is the vehicle behind it at gap i-1), The calculation method is as follows:

[0113]

[0114] Where h is the maximum headway of the ICV, which is the time interval between the front ends of two consecutive vehicles passing through a certain section.

[0115] By calculating all feasible gaps i∈I FTime of arrival of the preceding vehicle at the merging point Obtain the potential arrival time of vehicles on the ramp to the merging gap.

[0116] by For the merging time of ramp vehicles into the mainline, trajectory planning is performed on vehicles within and around the selected gap i that are ICVs (Integrated Vehicles) and ramp-cooperative ICVs. Under the premise of ensuring safe and timely merging into the mainline, the gap with the lowest energy consumption is selected as the merging gap. To this end, this section proposes a mathematical optimization model to obtain an optimal acceleration / deceleration curve for vehicles before and after the mainline gap and ramp-cooperative ICVs, minimizing vehicle energy consumption C. The objective function is:

[0117]

[0118] To obtain the optimal acceleration / deceleration curve, the decision variable is the vehicle's acceleration from t... o to t i,M vehicle acceleration a ve (t), whose constraints are as follows:

[0119]

[0120]

[0121] Where min is the function for finding the minimum value, C i The vehicle energy consumption corresponding to the i-th time slot on the main road, a ve Let ve = A,B,R be the vehicle acceleration, and let t be the acceleration of the vehicle when the vehicles in front and behind are intelligent connected vehicles (ICVs) at the selected gap, and ve = A,B,R be the acceleration of the vehicle. i,M t is the time it takes for the ramp-cooperative vehicle R to arrive at the merging point. i,M = v min v is the minimum speed of the vehicle. ve Let v be the vehicle's speed ve. max For maximum speed, a min Let a be the minimum acceleration of the vehicle. max v is the maximum acceleration of the vehicle. m x is the merging speed of the vehicles. ve For the vehicle's position ve, X ve_mer The vehicle's merging position is t0, the initial time is t0, and X is X. ve Here, t represents the vehicle's position, t is the calculation time when a given vehicle arrives at the merging point, and the time corresponding to the preceding vehicle in the mainline clearance i is... Ramp vehicle corresponding time is

[0122] In the model's constraints, the first and second equations represent restrictions on vehicle speed and acceleration to ensure driving safety; the third equation indicates that the speeds of ICV vehicles and their ramp-cooperating vehicles before and after the selected gap are equal to the merging speed v. m This ensures the safety of vehicles merging from the ramp; the fourth equation indicates that the position of the ICV vehicles and their ramp cooperating vehicles before and after the selected gap is the designated position at the merging point. When the vehicle is a ramp merging vehicle, i.e., ve = R, the vehicle's position at the designated merging point is X. R_mer When vehicle ve is in gaps between vehicle A in front or vehicle B in behind, X A_mer =X R_mer +v m ·h I_I X B_mer =X R_mer -v m ·h I_I Equation 5 represents the dynamic equation between the vehicle's velocity v and acceleration a when the vehicle arrives at the merging point on the ramp.

[0123] Equation 6 represents the dynamic equation relating vehicle position S and velocity v when a vehicle arrives at the merging point on the ramp. From this, the feasible vehicle clearance i∈I is obtained. F The corresponding energy consumption C i Then select energy consumption C i The smallest gap i is the merging gap, and it is removed from the selectable gaps in the next stage, i.e., I = I / i.

[0124] This embodiment includes the following collaborative optimization for ramp HDV:

[0125] When the merging vehicles on the ramp are HDVs, considering the uncertainty of the HDV vehicle trajectory, a car-following model is used to predict the arrival time of the ramp vehicles to the merging point. Then, for each feasible gap i∈I on the main road... F Vehicle speed is guided according to the gap adjustment method, and the optimal merging vehicle gap is calculated to ensure that vehicles on the ramp can reach the expected merging gap. The HDV collaborative optimization method for ramp merging vehicles is as follows:

[0126] (1) Estimated time for vehicles to arrive at the merging point from the ramp

[0127] For the ramp HDV currently being regulated, first sort all ramp vehicles within the control area from front to back, let n. r Assign vehicle numbers to the ramps within the control zone, and obtain the status (position, speed, acceleration) of that ramp vehicle and all vehicles following it within the control zone. Depending on the following type of vehicle, when ramp vehicle n... r When it is HDV, call the IDM car-following model; otherwise, when the ramp car n rWhen it is an ICV, if the preceding vehicle n r+1 When using HDV, call the ACC model if the preceding vehicle n r+1 When the vehicle is an ICV, the CACC model is invoked to obtain the status of all ramp vehicles in the next stage.

[0128] After obtaining the status information of all vehicles on the ramp at the current time step k, it is determined whether the position of the ramp HDV currently being regulated has reached the end of the control zone. If not, the above process is repeated to obtain the vehicle information for the next moment, until the ramp vehicle reaches the end of the acceleration lane, thus obtaining the expected time for the ramp HDV vehicle to reach the end point of the control zone. and speed Next, the time it takes for a vehicle on the ramp to accelerate from the end of the control zone to its merging speed is calculated. for:

[0129]

[0130] Where a dec For comfortable acceleration.

[0131] Finally, the travel distance S of the vehicle after reaching the merging speed on the ramp is obtained. ramp_mer for:

[0132]

[0133] Then accelerate to the position X where it merges. R,mer =X Col_end +S ramp_mer As a point of entry.

[0134] (2) Estimate the time for the preceding vehicle to arrive at the merging point in each gap.

[0135] The time when the preceding vehicle A reaches the control zone at the i-th gap in the feasible gaps on the main road is... speed is The time it takes for vehicle A to change speed to merge speed and then reach the merging point at a constant speed during the gap. for:

[0136]

[0137] Where t i,mer_acce Let be the running time of vehicle A before the i-th gap from entering the merging zone to the merging point.

[0138] t i,mer_acce The calculation method is as follows: First, calculate the time when the preceding vehicle A reaches the end of the control zone during the i-th gap. and corresponding speed From the formula for uniformly accelerated linear motion, we can obtain the comfortable acceleration and deceleration a of the vehicle A at the i-th gap. dec By speed Acceleration and deceleration to the combined speed v m distance When S ramp_mer ≥ΔS c,m At that time, the vehicle maintains uniform acceleration and deceleration until the merging point. When S ramp_mer <ΔS c,m Then, proceed to the next step of judgment, based on the initial speed at which the merging zone is reached. At that time, the vehicle decelerates uniformly to the merging speed and then reaches the merging point at a uniform speed. Otherwise, when initially reaching the merging zone speed... At that time, the vehicle accelerates uniformly to the merging speed and then returns to the merging point at a uniform speed. Therefore, t is obtained. i,mer_acce for:

[0139]

[0140] Calculate the arrival time of the preceding vehicle at the merging point for each gap i using the above formula. The preceding vehicle at gap i-1 is the following vehicle at gap i. The gap time when the preceding vehicle at gap i reaches the merging point... And the gap i behind the car When the interval is such that the vehicle on the ramp can just merge into the gap, this gap is selected as the merging gap for the ramp vehicle and removed from the selectable gaps in the next stage, i.e., I = I / i.

[0141] (3) Main road cooperative control method

[0142] For the gap i selected in (2), if the gap is greater than the merging safety gap, no adjustment is made; if it is less than the safety gap, the vehicle speed is guided according to the gap adjustment method so that the ramp vehicles can safely merge into the main road in the merging area.

[0143] The gap adjustment method first determines the vehicle type of the vehicles in front and behind the gap. If the vehicle in front is an HDV (High-Density Vehicle), it continues driving according to the car-following model. If the vehicle in front is an ICV (Independent Vehicle), it follows the trajectory optimization model. (The given input is...) Plan the trajectory of vehicle A ahead, when the vehicle on the ramp arrives at merging point X ramp_mer =X Col_End +S ramp_mer At that time, the vehicle's position X i,A,mer =X ramp_mer +v m ·h H_I , where X Col_End S represents the end position of the control area. ramp_mer The driving distance to enter the merge zone, h H_IThis is the safe headway when the preceding vehicle is an ICV and the following vehicle is an HDV. If the following vehicle is an ICV, the same calculation method as for the preceding vehicle is used to plan the trajectory of the following vehicle B. When the vehicle on the ramp reaches the merging point X... ramp_mer At that time, the vehicle's position X i,B,mer =X ramp_mer -v m ·h H_I .

[0144] To explain the method of this invention, implementation examples are given below to verify and analyze the model and algorithm. The collaborative control scheme for vehicle merging trajectories in the merging zone of a highway under mixed traffic flow was verified using SUMO and Python. SUMO (Simulation of Urban Mobility) is an open-source, highly portable, multimodal traffic simulation tool applicable to large-scale traffic networks.

[0145] To ensure continuous traffic flow in the simulated road segment, a vehicle generation model was established. The number of generated vehicles under low, medium, and high traffic densities was obtained by calculating the theoretical capacity of mixed traffic. The theoretical capacity of mixed traffic can be calculated as follows:

[0146]

[0147] In the formula C mix P represents the theoretical capacity (veh / h / lane) of mixed traffic. I This indicates the penetration rate of ICV. h HDV h ACC and h CACC These represent the desired time intervals, with values ​​of 1.5s, 1.1s, and 0.6s, respectively. e This indicates the equilibrium speed (maximum speed v on the main road). max ), s o lv represents the vehicle stationary clearance and vehicle length, taken as 2m and 500m respectively. Calculations show that the theoretical throughput of the mainline at ICV penetration rates of 20%, 40%, 60%, and 80% are 2143, 2338, 2647, and 3158 (veh·h) respectively. -1 The main line and ramps are input with the following formulas respectively:

[0148] Q m =C mix ·P ρ ·(1-P η )

[0149] Q r =C mix ·P ρ ·P η

[0150] Among them, P ρ P represents the percentage of total capacity. η This represents the proportion of vehicles on the ramps.

[0151] For the scenario of vehicle merging at highway entrance ramps under mixed traffic flow, a simulation experiment was conducted on the cooperative merging control under mixed traffic flow in the highway merging zone based on the SUMO simulation platform. First, the merging effects of no control and only gap adjustment control strategy (strategy 1) and the strategy of this invention (strategy 2) were compared under different traffic flow and ICV penetration rates. Second, the merging effects of each strategy under different ICV penetration rates at high density were analyzed. Then, the influence of different control area lengths in the vehicle trajectory planning cooperative optimization strategy on the merging effect was further analyzed.

[0152] In the merging scenario, the mainline is 1400m long, with a 700m section before the merging zone and a 500m mainline control zone. The ramps are 400m long, with a 200m ramp control zone. The merging zone is 200m long, and the lane width is 3.75m. The simulation duration is 600s (vehicle input duration is 300s), the simulation step size is 0.1s, the decision control step size is 0.5s, the vehicle's lateral position is at the center of the lane, and the maximum initial speed of vehicles on the mainline is 25.0 m / s. -1 The maximum initial speed of vehicles on the ramp is 16.7 m / s. -1 The simulation parameters are shown in Table 1.

[0153] Table 1 Simulation Parameters

[0154]

[0155]

[0156] In this case study, a comparative experiment was conducted on two schemes: no control strategy and vehicle dynamic cooperative merging control strategy (Strategy 2). The tests were mainly conducted under different ICV penetration rates and road densities. The specific test results are shown below:

[0157] Table 2 Comparison of strategy performance for different ICV penetration rates at different densities

[0158]

[0159] from Figures 5 to 12 As shown in Table 2, compared to the case without a strategy, under the cooperative merging control, the vehicle trajectories with the control strategy are more even, as can be seen from the vehicle trajectory and speed distribution maps. This means that there are fewer congestion situations during the merging process, the vehicles merge through the merging zone at a faster speed, and the vehicle throughput is higher. In addition, there are fewer color changes in the vehicle trajectory, which means that the vehicle speed trajectory is smoother, the vehicle acceleration changes less, and the energy consumption is lower.

[0160] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0161] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0162] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0163] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

[0164] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A method for collaborative control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow, characterized in that, Includes the following steps: The merging zone of the expressway is divided into a control zone and a merging zone. Based on the types and states of vehicles before and after the gap in the control zone, as well as the range of coordinated adjustment of safety distances and feasible gaps between different vehicle gaps, the feasible gap for the main road to merge is determined. Based on the feasible merging gaps on the main road and the vehicle's arrival time at the end of the control area, a trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption. This model is then used to iterate through all possible merging gaps on the main road, selecting the feasible gap with the lowest energy consumption as the merging gap for collaborative vehicle trajectory optimization control, including: Determine whether the vehicles merging into the ramp are intelligent connected vehicles or manually driven vehicles; If the vehicle merging on the ramp is an intelligent connected vehicle, the minimum arrival time of the preceding vehicle on the main road and the vehicle merging on the ramp to the end of the acceleration zone is calculated separately. Based on the feasible merging gaps on the main road, it is determined from front to back whether the minimum arrival time of the vehicle merging on the ramp to the end of the acceleration zone is less than or equal to the minimum arrival time of the preceding vehicle on the main road to the end of the acceleration zone. If so, a trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption. The energy consumption corresponding to the current time slot is determined using the trajectory optimization model, and the feasible gap with the minimum energy consumption is selected as the merging gap for vehicle trajectory collaborative optimization control. If the vehicle merging on the ramp is a manually driven vehicle, the time it takes for the vehicle to reach the merging point according to the car-following model is calculated. Then, based on the feasible merging gaps on the main road, the time for the preceding vehicle to reach the merging point in each time slot on the main road is calculated to determine the possible merging time slots for the vehicle merging on the ramp. Finally, the vehicle merging on the ramp follows the preceding vehicle according to the car-following model in the ramp control area, and at the same time, follows the preceding vehicle in the main road time slot in the acceleration area until the merging conditions are met and the vehicle merges.

2. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 1, characterized in that, Based on the vehicle types and states before and after the gap within the control zone, as well as the range of coordinated adjustments for safe distances and feasible gaps between different vehicle gaps, the feasible gaps for merging into the main road are determined, including: Starting from the first vehicle on the main line of the main road control zone, calculate the distance between vehicles before and after the vehicles in the gaps of the main road control zone; Determine whether the distance between vehicles before and after the gap is greater than or equal to the minimum safe gap; if so, merge the gap into a feasible gap as a main road; otherwise, adjust the gap before the end of the main road control area according to the type of vehicles before and after the gap to meet the requirement of a feasible gap.

3. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 2, characterized in that, A feasible gap is defined as the adjustment made before the end of the main road control zone according to the type of vehicles before and after the gap, to achieve the desired gap. This includes: When both the preceding and following vehicles are intelligent connected vehicles, the following vehicle decelerates at a comfortable deceleration while the preceding vehicle maintains a constant speed. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the preceding vehicle accelerates at its maximum safe acceleration while the following vehicle maintains a constant speed. The same process is repeated, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the following vehicle decelerates at a comfortable deceleration while the preceding vehicle accelerates at its maximum safe acceleration. The same process is repeated, determining whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is incorporated as a feasible clearance on the main road. Otherwise, the clearance is deemed infeasible. When the vehicles in front and behind are intelligent connected vehicles and manually driven vehicles, the following vehicle will decelerate at a comfortable deceleration and the preceding vehicle will drive at a constant speed. It will be determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control area. If so, the adjusted clearance will be merged into the feasible clearance as a main road; otherwise, the clearance will be an infeasible clearance. When the vehicles in front and behind are manually driven vehicles and intelligent connected vehicles, the vehicle in front is accelerated with the maximum safe acceleration and the vehicle behind is driven at a constant speed. It is then determined whether the minimum safe clearance is met when the vehicle in front reaches the end point of the main road control area. If so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the clearance is an infeasible clearance. When both the preceding and following vehicles are manually driven, the following vehicle is decelerated at a comfortable deceleration while the preceding vehicle is driven at a constant speed. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the end point of the main road control zone. If so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the clearance is considered infeasible.

4. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 3, characterized in that, The following vehicle decelerates at a comfortable deceleration while the preceding vehicle maintains a constant speed. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the end of the main road control zone, including: Based on the speed of the following vehicle and the time it takes for the preceding vehicle to reach the end point of the main road control zone at a constant speed, calculate the speed of the following vehicle as it continues to decelerate until the end point of the main road control zone. Determine whether the speed of the following vehicle as it decelerates until the end of the main road control zone is less than the minimum speed limit; if so, calculate the position of the following vehicle as it decelerates until the end of the main road control zone; otherwise, calculate the position of the following vehicle as it decelerates first and then travels at a constant speed during the control zone's operating segment. Calculate the distance between vehicles when the vehicle in front reaches the end of the control zone based on the position of the vehicle behind, and determine whether the distance between vehicles meets the minimum safe clearance; if so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the adjustment fails.

5. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 3, characterized in that, Accelerate the vehicle in front with maximum safe acceleration and keep the vehicle behind at a constant speed. Determine whether the minimum safe clearance is met when the vehicle in front reaches the end of the main road control zone, including: Calculate the speed of the vehicle ahead of the preceding vehicle when it reaches the end point of the main road control zone based on the time it takes for the preceding vehicle to travel at a constant speed from the initial point to the end point of the main road control zone. Determine the speed of the vehicle in front, calculate the distance traveled after the vehicle accelerates to its maximum speed, and determine whether the distance traveled is less than the distance between the vehicle in front and the end point of the control zone at the beginning of the gap; if so, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly accelerating to its maximum speed; otherwise, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly decelerating. The distance between vehicles in front and behind is calculated based on the time it takes for the preceding vehicle to reach the end point of the control zone. It is then determined whether the distance between vehicles in front and behind meets the minimum safe clearance. If so, the adjusted clearance is merged into the feasible clearance as a main road. Otherwise, the adjustment fails.

6. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 3, characterized in that, The following vehicle decelerates at a comfortable deceleration while the preceding vehicle accelerates at maximum safe acceleration. It is then determined whether the minimum safe clearance is met when the preceding vehicle reaches the main road control zone point, including: Calculate the speed of the vehicle ahead of the preceding vehicle when it reaches the end point of the main road control zone based on the time it takes for the preceding vehicle to travel at a constant speed from the initial point to the end point of the main road control zone. Determine the speed of the vehicle in front, calculate the distance traveled after the vehicle accelerates to its maximum speed, and determine whether the distance traveled is less than the distance between the vehicle in front and the end point of the control zone at the beginning of the gap; if so, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly accelerating to its maximum speed; otherwise, calculate the time it takes for the vehicle in front to reach the end point of the control zone after uniformly decelerating. Calculate the position of the following vehicle based on the time it takes for the preceding vehicle to reach the end point of the control zone; Calculate the distance between vehicles in front and behind based on the position of the following vehicle, and determine whether the distance between vehicles in front and behind meets the minimum safe clearance; if so, the adjusted clearance is merged into the feasible clearance as a main road; otherwise, the adjustment fails.

7. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 1, characterized in that, The minimum arrival time for the vehicle ahead in the main road time slot to reach the end of the acceleration zone is calculated as follows: The travel time of the preceding vehicle from the end point of the main road control zone to the merging point is divided into the time for the preceding vehicle to accelerate to its maximum speed, the time for the preceding vehicle to travel a certain distance at a constant speed at its maximum speed, and the time for the preceding vehicle to decelerate to the merging speed at the merging point. The minimum arrival time for the vehicle ahead in the main road time slot to reach the end of the acceleration zone is calculated using the following formula, expressed as: ； in, The minimum arrival time for vehicle A, preceding vehicle A in the i-th time slot of the main road, to reach the end of the acceleration zone. To find the maximum value function, The time it takes for the car in front to accelerate to its maximum speed. The time it takes for the vehicle in front to travel a certain distance at its maximum constant speed. The time it takes for the preceding vehicle to decelerate uniformly to reach the merging velocity at the merging point. The minimum arrival time for the vehicle preceding the i-1th time slot on the main road from the end point of the control area to the merging point. This represents the maximum headway.

8. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 1, characterized in that, The minimum arrival time for vehicles merging from the ramp to reach the end of the acceleration zone is calculated as follows: = ； in, This is the minimum arrival time for vehicles merging from the ramp to reach the end of the acceleration zone. The minimum arrival time for vehicle A, preceding vehicle A in the i-th time slot of the main road, to reach the end of the acceleration zone. This represents the maximum headway.

9. The method for coordinated control of vehicle merging trajectories in the merging zone of a highway under mixed traffic flow as described in claim 1, characterized in that, The trajectory optimization model is established with the goal of minimizing vehicle operating energy consumption as follows: ； st and={A,B,R}; and={A,B,R}; and={A,B,R}; and={A,B,R}; , ； , ； Where min is the function for finding the minimum value. The vehicle energy consumption corresponding to the i-th time slot on the main road. To accelerate the vehicle, To determine the preceding vehicle A and the following vehicle B, along with their ramp-cooperating vehicle R, when the vehicles in front and behind the selected gap are intelligent connected vehicles (ICVs), The time it takes for the ramp-cooperative vehicle R to arrive at the merging point. Minimum speed for the vehicle. For the vehicle's speed ve, For maximum speed, The minimum acceleration of the vehicle. This is the vehicle's maximum acceleration. For vehicle merging speed, The location where the vehicles merge is t0, and the initial time is t0. Let t represent the vehicle's position, and t represent the time it takes for the vehicle to arrive at the merging point.

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