Expressway traffic jam elimination method based on network automatic driving technology

Abstract

The invention discloses an expressway traffic jam elimination method based on a network automatic driving technology, and relates to the technical field of expressway traffic jam dissipation. When a traffic jam is detected, the network automatic driving technology is applied to decelerate a specified vehicle at the upstream of a jam area to a specified speed; a large distance is kept between the designated vehicle and the downstream congestion; then, after the specified vehicle runs at the specified speed for a period of time, when the specified vehicle is at a certain specified distance away from the vehicle in front of the specified vehicle, the vehicle is accelerated and recovered to the free flow speed before deceleration; correspondingly, the follow-up vehicle of the specified vehicle is adjusted according to the change of the driving behavior of the front vehicle; and finally, evanescent waves generated by acceleration of the specified vehicle meet compression waves generated by deceleration of the specified vehicle, and congestion is completely eliminated. According to the method, the initiative, flexibility, accuracy and efficiency of congestion elimination are improved, and the problems that an existing method is passive in control mode, low in accuracy and not ideal in effect are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of eliminating traffic congestion on expressways, and in particular to a method for eliminating traffic congestion on expressways based on networked autonomous driving technology. Background Art

[0002] At present, domestic and foreign research on eliminating traffic congestion on expressways mainly focuses on fixed bottleneck areas such as divergence and merging areas. The control method is passive, with low precision and unsatisfactory effect by setting speed limit signs and traffic lights at fixed locations. With the development of networked autonomous driving technology, real-time detection of traffic operation status, extraction of vehicle dynamic trajectory data, real-time release of vehicle network information, and high-precision vehicle autonomous driving have gradually become possible. Therefore, based on networked autonomous driving technology, by actively regulating vehicle driving behavior and coordinating the operation status of congested upstream and downstream traffic flows, congestion or fluctuations can be eliminated dynamically in real time. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for eliminating fast road traffic congestion based on networked autonomous driving technology, which solves the problems of passive control mode, low precision and unsatisfactory effect of the prior art.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a method for eliminating traffic congestion on a fast road based on networked autonomous driving technology, comprising the following steps:

[0005] S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain the vehicle operation status data;

[0006] S2: Based on vehicle operation status data and connected autonomous driving technology, when the cloud control platform detects the formation of downstream traffic congestion, the designated vehicles upstream of the congestion area will be decelerated to the specified speed in advance, so that the designated vehicles maintain a specified distance from the downstream congested vehicles;

[0007] S3: When the upstream designated vehicle is at a designated distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate and recover to the free flow speed before deceleration;

[0008] S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted in sequence according to the changes of the leading vehicle;

[0009] S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on the connected autonomous driving technology is completed.

[0010] The beneficial effects of the above scheme are: using the networked automatic driving technology to slow down a designated vehicle upstream of the congested area to a designated speed, so that the designated vehicle maintains a large distance from the congestion downstream; then, after the designated vehicle has traveled at the designated speed for a period of time, when the designated vehicle is at a designated distance from the vehicle in front of it, the vehicle is accelerated to recover to the free flow speed before deceleration; accordingly, the subsequent vehicles following the designated vehicle are adjusted according to the change in the driving behavior of the vehicle in front. Finally, the dissipation wave generated by the acceleration of the designated vehicle meets the compression wave generated by the deceleration, and the congestion is completely eliminated. Based on the networked automatic driving technology, the present invention actively controls the driving behavior of individual vehicles, replacing the passive, wide-area method of implementing signal, speed, and flow control at a fixed position, thereby improving the initiative, flexibility, accuracy and efficiency of congestion elimination, and solving the problems of passive control methods, low accuracy and unsatisfactory effects of existing methods.

[0011] Furthermore, the deceleration time of the upstream designated vehicle in S2 is the time when the congestion is detected after it is fully formed, and the formula is:

[0012] t 减速 =t1

[0013] Among them, t 减速 is the deceleration moment of the leading vehicle in the upstream of the congestion, and t1 is the moment when the congestion is detected after it is fully formed.

[0014] The beneficial effect of the above further solution is that: through the above technical solution, the moment when congestion is fully formed and detected is used as the deceleration moment of the upstream designated vehicle.

[0015] Furthermore, the upstream designated vehicle in S2 decelerates to the designated speed in advance, and the formula is:

[0016]

[0017] Among them, v ai is the speed after deceleration when the designated vehicle i is the deceleration head vehicle. is the position where vehicle i-1 accelerates to leave the congestion after driving at the current free flow speed, d is the parking distance between adjacent vehicles, is the position of vehicle i at time t1, t i-1 It is the moment when vehicle i-1 accelerates to leave the traffic jam after traveling at the current free flow speed and getting stuck in the traffic jam.

[0018] The beneficial effect of the above further solution is that through the above technical solution, the speed that the congested upstream vehicle can maintain after deceleration is obtained.

[0019] Furthermore, the expected headway distance for the upstream designated vehicle in S2 to decelerate to the designated speed in advance is:

[0020] hai =v ai *t e

[0021] Among them, h ai is the expected headway distance corresponding to the decelerated speed, t e is the headway time expected by the driver.

[0022] The beneficial effect of the above further scheme is that: through the above technical scheme, the headway of the designated decelerated vehicles upstream of the congestion that accelerate to recover to the free flow speed is the expected headway corresponding to the free flow speed.

[0023] Furthermore, the vehicle i specified in S2 satisfies the following conditions:

[0024]

[0025] Among them, Δt is the delay time of a single vehicle in congestion, When vehicle i is designated as the upstream leading vehicle for early deceleration, the time when the last decelerated vehicle returns to the free flow speed before deceleration. When vehicle i-1 is the leading vehicle in the upstream pre-deceleration, the moment when the last decelerating vehicle returns to the free flow speed before deceleration. The time when the last decelerated vehicle returns to the free flow speed before deceleration when the designated vehicle i+1 is used as the upstream leading vehicle for early deceleration;

[0026]

[0027] in, is the time when vehicle i is decelerated and then accelerated when it is designated as the deceleration head vehicle, T i is the time required for the dissipation wave generated by the acceleration of the specified vehicle i to catch up with the compression wave generated by its deceleration, l is the headway distance when the specified vehicle i returns to the free flow speed before deceleration, v f is the free flow speed of the vehicle, is the position where vehicle i accelerates, is the position where vehicle i decelerates, h1 is the headway between vehicles upstream in the congestion area, and t 检测 is the time when the designated vehicle i decelerates, t0 is the time when the first vehicle caught in congestion starts to decelerate, x0 is the position where the first vehicle caught in congestion starts to decelerate, and x1 is the position where the first vehicle caught in congestion accelerates to recover to the free flow speed.

[0028] The beneficial effect of the above further scheme is: in order to eliminate traffic congestion as soon as possible, the leading vehicle in the upstream of the congestion that slows down in advance should allow the last vehicle participating in the deceleration to return to the free flow speed as soon as possible. That is, the moment when the compression wave caused by the deceleration and acceleration of the vehicle meets the dissipation wave is also the moment when the congestion is completely eliminated.

[0029] Furthermore, the headway distance between vehicles when the vehicle accelerates and recovers to the free flow speed before deceleration is specified in S3 as:

[0030] l=v f *t e .

[0031] The beneficial effect of the above further solution is that: through the above technical solution, the headway of the designated decelerated vehicles upstream of the congestion that accelerate to recover to the free flow speed is the expected headway corresponding to the free flow speed.

[0032] Furthermore, the time at which the vehicle accelerates is specified in S3 as:

[0033]

[0034] The beneficial effect of the above further scheme is: through the above technical scheme, the time when the leading vehicle of the upstream decelerating vehicles in the congestion accelerates is designated as the time when the distance between the leading vehicle and the previous vehicle (the last vehicle caught in the congestion) is 1 meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flow chart of a method for eliminating traffic congestion on expressways based on connected autonomous driving technology.

[0036] Figure 2 This is a system structure diagram of an example of the present invention.

[0037] Figure 3 It is an implementation effect diagram of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] like Figure 1 As shown, a method for eliminating fast road traffic congestion based on networked autonomous driving technology includes the following steps:

[0040] S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain the vehicle operation status data;

[0041] S2: Based on vehicle operation status data and connected autonomous driving technology, when the cloud control platform detects the formation of downstream traffic congestion, the designated vehicles upstream of the congestion area will be decelerated to the specified speed in advance, so that the designated vehicles maintain a specified distance from the downstream congested vehicles;

[0042] S3: When the upstream designated vehicle is at a designated distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate and recover to the free flow speed before deceleration;

[0043] S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted in sequence according to the changes of the leading vehicle;

[0044] S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on the connected autonomous driving technology is completed.

[0045] In one embodiment of the present invention, Figure 2 As shown, the system structure of the present invention is shown, that is, the vehicle networking technology is used to detect the running status data of the expressway vehicles and upload it to the cloud data management center. The data management center transmits the results to the cloud control platform after calculation and analysis. The cloud control platform formulates strategies and issues control instructions to the vehicles in the expressway system. The specific implementation is as follows:

[0046] Traffic operation status detection: A vehicle networking data management center is set up on the expressway, and the connected autonomous driving vehicles on the expressway upload their position, speed, and headway distance to the data management center every 0.1s.

[0047] Traffic jam generation and propagation: At time t1, a traffic jam is detected at x meters from lane 1 and propagates steadily upstream along the lane. The speed of vehicles upstream of the congestion area is the free flow speed v f , the headway is h1; the speed of the vehicle stuck in the jam is 0, the headway is d; the speed of the vehicle resuming driving after stopping in the jam is v f , the headway between the two vehicles is h1.

[0048] Vehicle control parameter design and calculation: After detecting the formation and propagation of congestion, design and calculate the corresponding parameters of the vehicle control method aimed at eliminating congestion, including:

[0049] The deceleration time of the upstream designated vehicle in S2 is the time when the congestion is detected after it is fully formed, and the formula is:

[0050] t 减速 =t1

[0051] Among them, t 减速is the deceleration moment of the leading vehicle in the upstream of the congestion, and t1 is the moment when the congestion is detected after it is fully formed.

[0052] The upstream designated vehicle in S2 decelerates to the designated speed in advance. The formula is:

[0053]

[0054] Among them, v ai is the speed after deceleration when the designated vehicle i is the deceleration head vehicle. is the position where vehicle i-1 accelerates to leave the congestion after driving at the current free flow speed, d is the parking distance between adjacent vehicles, is the position of vehicle i at time t1, t i-1 It is the moment when vehicle i-1 accelerates to leave the traffic jam after traveling at the current free flow speed and getting stuck in the traffic jam.

[0055] The expected headway distance for the upstream designated vehicle in S2 to decelerate to the designated speed in advance is:

[0056] h ai =v ai *t e

[0057] Among them, h ai is the expected headway distance corresponding to the decelerated speed, t e is the headway time expected by the driver. In S2, vehicle i is specified to meet the following conditions:

[0058]

[0059] Among them, Δt is the delay time of a single vehicle in congestion, When vehicle i is designated as the upstream leading vehicle for early deceleration, the time when the last decelerated vehicle returns to the free flow speed before deceleration. When vehicle i-1 is the leading vehicle in the upstream pre-deceleration, the moment when the last decelerating vehicle returns to the free flow speed before deceleration. The time when the last decelerated vehicle returns to the free flow speed before deceleration when the designated vehicle i+1 is used as the upstream leading vehicle for early deceleration;

[0060]

[0061] in, is the time when vehicle i is decelerated and then accelerated when it is designated as the deceleration head vehicle, T i is the time required for the dissipation wave generated by the acceleration of the specified vehicle i to catch up with the compression wave generated by its deceleration, l is the headway distance when the specified vehicle i returns to the free flow speed before deceleration, v f is the free flow speed of the vehicle, is the position where vehicle i accelerates, is the position where vehicle i decelerates, h1 is the headway between vehicles upstream in the congestion area, and t 检测 is the time when the designated vehicle i decelerates, t0 is the time when the first vehicle caught in congestion starts to decelerate, x0 is the position where the first vehicle caught in congestion starts to decelerate, and x1 is the position where the first vehicle caught in congestion accelerates to recover to the free flow speed.

[0062] The headway distance when the vehicle accelerates and returns to the free flow speed before deceleration in S3 is:

[0063] l=v f *t e .

[0064] The time when the vehicle accelerates is specified in S3:

[0065]

[0066] From the above steps, it can be seen that each time a vehicle is tried as the head vehicle of the upstream deceleration in the congestion, the above control parameters corresponding to the vehicle as the head vehicle of the upstream deceleration in the congestion can be obtained, that is, the deceleration time t1 of the vehicle (the time when the congestion is detected), the position x at the time of deceleration i , the speed that the vehicle can maintain after decelerating as the lead vehicle Headroom h ai , Acceleration time The moment when the congestion is completely eliminated i .

[0067] Based on this, we tried and calculated the N+1 vehicles upstream of the congestion, and obtained the control parameters and effects of each vehicle as the deceleration head vehicle upstream of the congestion, as shown in Table 1:

[0068] Table 1 Control parameters and results of selecting vehicle i as the deceleration head vehicle

[0069]

[0070] Select the leading vehicle that decelerates in advance upstream of the congestion: In order to eliminate traffic congestion as soon as possible, the leading vehicle that decelerates in advance upstream of the congestion should make the last vehicle participating in the deceleration return to the free flow speed as soon as possible, that is, the moment when the compression wave caused by vehicle deceleration and acceleration meets the dissipation wave, which is also the moment when the congestion is completely eliminated. The leading vehicle i meets the following conditions:

[0071]

[0072] From Table 1, we can see that:

[0073]

[0074] Therefore, the Mth vehicle at the upstream of the congestion is selected as the first vehicle to decelerate in advance.

[0075] Let the Mth vehicle upstream of the congestion slow down to v at time t1 am , and the following vehicles follow accordingly, with a head-to-head distance h am Keep moving.

[0076] Downstream congested vehicles at t m-1 All vehicles are restored to free flow speed at all times, leaving the congestion, and all congested vehicles are eliminated.

[0077] Let the Mth vehicle upstream of the congestion be Start accelerating to the free flow speed v f , the other decelerating vehicles behind this vehicle accelerate one by one to the free flow speed v f and head spacing 1.1v f Keep moving.

[0078] The last decelerated vehicle upstream of the congestion resumes its speed to the free flow speed v f , the congestion is completely eliminated. Subsequent vehicles are no longer affected by the congestion and maintain a stable free flow speed. Figure 3 As shown, the motion wave is completely eliminated. Each line in the figure represents the space-time trajectory of each vehicle, that is, the corresponding position of the vehicle at each moment, and the color represents the speed of the vehicle, that is, the slope of the line.

[0079] The present invention can detect and obtain the operating status of vehicles and traffic flows with high precision through vehicle network technology, and can control vehicle driving behavior and traffic operating status with high precision through automatic driving technology; by controlling the driving behavior of individual vehicles upstream of the congestion, the operating status of traffic flows upstream and downstream of the congestion can be coordinated, thereby completely eliminating the congestion. Compared with traditional manual coordination and control methods of the placement of restrictive facilities (speed limit boards, traffic lights, etc.), the present invention can completely eliminate traffic congestion in real time, greatly save the cost of congestion control, and significantly improve the initiative, flexibility, accuracy and efficiency of congestion elimination.

[0080] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the invention.

Claims

1. A method for eliminating traffic congestion on expressways based on networked autonomous driving technology, characterized in that: The following steps are involved: S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain the vehicle operation status data; S2: Based on vehicle operation status data and connected autonomous driving technology, when the cloud control platform detects the formation of downstream traffic congestion, the designated vehicles upstream of the congestion area will be decelerated to the specified speed in advance, so that the designated vehicles maintain a specified distance from the downstream congested vehicles; S3: When the upstream designated vehicle is at a designated distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate and recover to the free flow speed before deceleration; S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted in sequence according to the changes of the leading vehicle; S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on the connected autonomous driving technology is completed.

2. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 1, characterized in that: The deceleration time of the upstream designated vehicle in S2 is the time when the congestion is detected after it is fully formed, and the formula is: t 减速 =t1 Among them, t 减速 is the deceleration moment of the leading vehicle in the upstream of the congestion, and t1 is the moment when the congestion is detected after it is fully formed.

3. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 2, characterized in that: The upstream designated vehicle in S2 decelerates to the designated speed in advance, and the formula is: Among them, v ai is the specified speed after deceleration when the designated vehicle i is the deceleration head vehicle, is the position where vehicle i-1 accelerates to leave the congestion after driving at the current free flow speed, d is the parking distance between adjacent vehicles, is the position of vehicle i at time t1, t i-1 It is the moment when vehicle i-1 accelerates to leave the traffic jam after traveling at the current free flow speed and getting stuck in the traffic jam.

4. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 3, characterized in that: The expected headway distance for the upstream designated vehicle in S2 to decelerate to the designated speed in advance is: h ai =v ai *t e Among them, h ai is the expected headway distance corresponding to the decelerated speed, t e is the headway time expected by the driver.

5. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 4, characterized in that: The vehicle i specified in S2 satisfies the following conditions: Among them, Δt is the delay time of a single vehicle in congestion, When vehicle i is designated as the upstream leading vehicle for early deceleration, the time when the last decelerated vehicle returns to the free flow speed before deceleration. When vehicle i-1 is the leading vehicle in the upstream pre-deceleration, the moment when the last decelerating vehicle returns to the free flow speed before deceleration. The time when the last decelerated vehicle returns to the free flow speed before deceleration when the designated vehicle i+1 is used as the upstream leading vehicle for early deceleration; in, is the time when vehicle i is decelerated and then accelerated when it is designated as the deceleration head vehicle, T i is the time required for the dissipation wave generated by the acceleration of the specified vehicle i to catch up with the compression wave generated by its deceleration, l is the headway distance when the specified vehicle i returns to the free flow speed before deceleration, v f is the free flow speed of the vehicle, is the position where vehicle i accelerates, is the position where vehicle i decelerates, h1 is the headway between vehicles upstream in the congestion area, and t 检测 is the time when the designated vehicle i decelerates, t0 is the time when the first vehicle caught in congestion starts to decelerate, x0 is the position where the first vehicle caught in congestion starts to decelerate, and x1 is the position where the first vehicle caught in congestion accelerates to recover to the free flow speed.

6. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 5, characterized in that: The headway distance when the vehicle accelerates and recovers to the free flow speed before deceleration specified in S3 is: l=v f *t e 。 7. The method for eliminating traffic congestion on expressways based on networked autonomous driving technology according to claim 6, characterized in that: The time for the vehicle to accelerate is specified in S3 as:

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