CN114495556B - Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway - Google Patents
Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway Download PDFInfo
- Publication number
- CN114495556B CN114495556B CN202210061844.1A CN202210061844A CN114495556B CN 114495556 B CN114495556 B CN 114495556B CN 202210061844 A CN202210061844 A CN 202210061844A CN 114495556 B CN114495556 B CN 114495556B
- Authority
- CN
- China
- Prior art keywords
- vehicles
- ramp
- distance
- formation
- vehicle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/123—Traffic control systems for road vehicles indicating the position of vehicles, e.g. scheduled vehicles; Managing passenger vehicles circulating according to a fixed timetable, e.g. buses, trains, trams
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/20—Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Traffic Control Systems (AREA)
- Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
Abstract
The invention relates to a method for setting an optimal formation length for automatic driving under the constraint of ramp spacing of a highway, which comprises the following steps: s1, obtaining a distance L between a ramp a and a ramp b of the expressway, and obtaining running state parameters of an automatic driving traffic flow of an upstream main line of the ramp a, wherein the running state parameters comprise the number n of the existing formation vehicles 1 The existing formation stable running speed
S2, simulating the marshalling and ungrouping process between the vehicles on the upper ramp and the existing formation vehicles through computer simulation; s3, selecting the shortest stable running time t of vehicle formation 1 (ii) a S4, limiting L and limiting t according to ramp distance and shortest stable operation time 1 Calculating the maximum number n of vehicles to be combined 2 And obtaining the optimal formation length of the automatic driving traffic flow running on the highway. The invention has the advantages of efficiency guarantee, simple and convenient calculation, energy consumption saving, safety, reliability and the like.
Description
Technical Field
The invention relates to the technical field of traffic control systems of road vehicles, in particular to a method for setting the optimal formation length of automatic driving under the constraint of ramp spacing of a highway.
Background
The automatic driving vehicle fleet grouping technology is characterized in that vehicle-to-vehicle cooperative communication or vehicle-to-road cooperative communication is utilized in the driving process of automatic driving vehicle flows, so that the distance between vehicle heads of the automatic driving vehicle flows is reduced, the driving speed is kept consistent, and limited road resources can be better utilized.
However, in the process of grouping, as the length of a vehicle fleet increases, the overall driving safety is reduced, and the fluctuation of grouping is increased, so that the automatic driving traffic grouping has an optimal grouping length in consideration of the influence of various factors on the grouping process.
Taking an expressway environment as an example, since vehicles may enter and exit through ramps on an expressway, assuming that the entering vehicles will exit on the next ramp, and a train of vehicles on the expressway is still running, the entering vehicles on the ramps need to consider whether to join the train according to various limiting conditions, such as running distance, stable running time, and the like.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for setting the optimal formation length for automatic driving under the constraint of the ramp distance of the expressway, which has the advantages of efficiency guarantee, simple and convenient calculation, energy consumption saving, safety and reliability.
The technical scheme adopted by the invention for solving the technical problems is as follows: a method for setting the optimal formation length for automatic driving under the restriction of the ramp spacing of a highway is constructed, and comprises the following steps:
s1, obtaining a distance L between a ramp a and a ramp b of the expressway, and obtaining running state parameters of an automatic driving traffic flow of an upstream main line of the ramp a, wherein the running state parameters comprise the number n of the existing formation vehicles 1 The existing formation stable running speed v-;
s2, simulating the marshalling and ungrouping process between the vehicles on the upper ramp and the existing formation vehicles through computer simulation;
s3, selecting the shortest stable running time t of vehicle formation 1 ；
S4, limiting L according to ramp distance and limiting t according to shortest stable operation time length 1 Calculating the maximum number n of vehicles to be combined 2 And obtaining the optimal formation length of the automatic driving traffic stream running on the highway.
According to the scheme, the core method in the simulation process in the step S2 is as follows:
s201, separately controlling longitudinal and transverse distances between vehicles, and respectively controlling the transverse distances between the vehicles to be coordinated to 0 and the longitudinal distances to be coordinated to an ideal distance;
s202, establishing an attraction and repulsion model between vehicles, avoiding collision in the process of carrying out cooperation, and establishing an attraction-repulsion function;
and S203, generating a vehicle formation.
According to the above scheme, the attraction-repulsion function established in step S202 is:
three adjacent vehicles respectively form three different longitudinal acting forces according to respective longitudinal intervals
Gradually adjusting the motion of the vehicles by longitudinal force to coordinate the longitudinal spacing between the vehicles to be consistent, wherein the attraction-repulsion function of the longitudinal spacing between the vehicles is as follows:
in the formula: the polyfit function is a self-defined S-shaped function when h is 1 Close to 0, the value is 1, at h 1 The value is 0 near r; h is 1 The ratio of the longitudinal distance between the vehicles after the function transformation to the ideal distance after the function transformation; r is a constant;
three adjacent vehicles are subjected to different transverse forces
The transverse movement of the vehicle is gradually adjusted through the transverse acting force, so that the transverse position of the vehicle is coordinated to the central line of the lane, an attraction-repulsion function of the transverse distance is established,
in the formula: h is 2 Is the value of the transverse distance between the vehicles after the functional transformation; r is 2 Is a constant.
According to the scheme, the step of generating the vehicle formation in the step S203 comprises the following steps:
s20301, inputting the number n of the vehicles in the formation 1 Randomly generating the position and speed of the initial vehicle, wherein the position of the initial randomly generated vehicle is within the designated area size, and avoiding too close proximity between the vehicles;
s20302, giving the state of the virtual leader: when the vertical coordinate of the virtual leader is generated, the vertical coordinate is kept consistent with the size, the horizontal coordinate is the position of the center line of the lane, then the formation stable running speed v-is given to the virtual leader, and the motion acceleration of the virtual leader is as follows:
controlling the acceleration to [ -5,3]m/s 2 Within a, and a leader Is subjected to v leader The feedback effect of (c).
According to the scheme, the specific steps of the step S4 are as follows:
s401, setting the number n of vehicles in the vehicle group on the ramp 2 An initial value of (1);
s402, calculating the distance L when the two fleets complete the cooperation and reach the stability 1 Carrying out envelope fitting on the speed change in the fluctuation process by utilizing the right part of the log-normal distribution curve, and considering that the stable state is achieved when the distance between envelope lines is less than 0.3m/s of a threshold value;
the formula for the right-hand curve inserted into log-normal distribution is:
in the formula: a. b and c are parameters to be solved, and when x = e b When f (x) reaches a peak value, then when x ≧ e b Then the right curve of the lognormal distribution can be taken;
s403, calculating the running distance L under the stable running time 2 Wherein
S404, calculating the running distance L in the process of fleet decomposition and compilation 3 The completion of the solution editing means that the speed difference of the vehicles in two different fleets is within 0.3m/s, the distance difference between the vehicle heads is within 0.3m, and the absolute value of the acceleration difference is within 0.1m/s 2 Within, L 3 The calculation of (2) is from the time of starting the decompiling to the time of finishing the decompiling;
s405, judging L 1 +L 2 +L 3 Whether the length limit L is exceeded;
s406, increasing n by taking '1' as a step length when the number of the n-shaped groups is not reached 2 ；
S407, repeating the step S406 until the last n is obtained 2 At this time n 1 +n 2 Namely the optimal formation length of the automatic driving traffic flow under the restriction of the ramp distance of the expressway.
According to the scheme, the ramp of the expressway comprises an expressway lane, a ramp entrance of the expressway and a ramp exit of the expressway.
According to the scheme, the shortest stable running time t of the vehicle formation is selected in the step S3 1 Was 1 minute.
According to the above scheme, the step S4 further includes the following steps: the horizontal axis of the plane coordinate system is taken as time, the vertical axis of the plane coordinate system is taken as travel distance, and the number n of different vehicles is plotted 2 The lower curve cluster.
The method for setting the optimal formation length for automatic driving under the constraint of the ramp spacing of the expressway has the following beneficial effects:
the invention provides a method for setting the optimal formation length of automatic driving under the constraint of the ramp spacing of a highway, which is characterized in that the initial running state of the existing motorcade is obtained, the displacement in the processes of regrouping, stable running and decompiling is respectively calculated, and the number of vehicles which are imported on the ramp is adjusted through feedback, so that the optimal formation length of an automatic driving traffic flow is obtained, the overall thought is simpler, and the complex mathematical calculation is avoided.
Drawings
FIG. 1 is a schematic view of the analysis of vehicle forces during the grouping and compiling process of the present invention;
FIG. 2 is a schematic diagram of an automatic driving traffic stream formation process on a ramp of a highway according to the invention, which is a formation initial process;
FIG. 3 is a schematic diagram of a regrouping process of an automatic driving traffic stream formation process on a ramp of a highway according to the present invention;
FIG. 4 is a schematic illustration of a steady driving process of an autonomous driving traffic stream formation process on a freeway ramp according to the present invention;
FIG. 5 is a schematic diagram of the de-compilation process of the formation process of the automatic driving traffic on the ramp of the highway in the present invention;
FIG. 6 is a function image of the polipit function of the present invention;
FIG. 7 shows n in the present invention 2 A schematic diagram of judging stability by using a lognormal envelope curve when = 4;
FIG. 8 shows the difference n in the present invention 2 A corresponding driving curve;
FIG. 9 is a flow chart of the method of the present invention.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in fig. 9, the method for determining the optimal formation length of the autonomous driving traffic flow under the restriction of the ramp distance of the expressway of the invention comprises the following steps:
s1, obtaining the distance L between a ramp a and a ramp b of the highway and the running state parameters of the automatic driving traffic flow of the main line at the upstream of the ramp a, wherein the running state parameters comprise the number n of the vehicles in the prior formation 1 The existing formation stable running speed
As shown in fig. 2, the expressway ramp includes an expressway lane, a ramp entrance of the expressway, and a ramp exit of the expressway;
s2, simulating the marshalling and ungrouping process between the vehicles on the upper ramp and the existing formation vehicles by means of computer simulation, wherein the core method in the simulation process is as follows:
s201, separately controlling longitudinal and transverse distances between vehicles, and respectively controlling the transverse distances between the vehicles to be coordinated to 0 and the longitudinal distances to be coordinated to an ideal distance;
s202, an attraction model and a repulsion model between vehicles need to be established, and the situations of collision and the like in the process of cooperation are avoided, because longitudinal direction is vertical to each otherThe distance needs to be coordinated to a desired distance, so that an attraction-repulsion function as shown in formula (2-1) is established, when the longitudinal distance between the vehicles is shorter, the generated impedance is larger, so that collision between the vehicles is avoided, when the distance is moderate, attraction is generated between the vehicles, and when the distance is larger, the vehicles cannot be mutually influenced. As shown in FIG. 1, when the longitudinal distances between the vehicles are not coordinated to be consistent, different longitudinal forces are generated between the vehicles according to the longitudinal distances, and three vehicles respectively generate three different longitudinal forces according to the respective longitudinal distances
The movement of the vehicles is gradually adjusted by the longitudinal force so that the longitudinal spacing between the vehicles is coordinated to be consistent. The attraction-repulsion function for the longitudinal spacing between the vehicles at this time is:
in the formula: the polyfit function is a self-defined S-shaped function when h is 1 Close to 0, the value is 1, at h 1 This value is 0 near r, see FIG. 3; h is 1 The ratio of the longitudinal distance between the vehicles after the function transformation to the ideal distance after the function transformation; r is a constant;
when the vehicle initially moves, the transverse positions on the lane are not all on the lane central line, as shown in fig. 1, in order to form a complete cooperative queue, the transverse distance of the vehicle needs to be coordinated to 0, namely, the vehicle keeps running at the lane central line position, when the vehicle is far away from the lane central line, the vehicle is influenced by the transverse acting force to be close to the lane central line, and in fig. 1, three vehicles are influenced by different transverse acting forces
Gradually adjusting the transverse movement of the vehicle by the transverse acting force, so that the transverse position of the vehicle is coordinated to the central line of the lane. Thus, the attraction-repulsion function that establishes the lateral separation is shown in equation (2-2), when the lateral distances between the vehicles are very close,the vehicles do not affect each other, and when the lateral distance is larger in a certain range, the attraction generated is larger, so that the cooperation between the vehicles is accelerated. The transverse spacing of the vehicle is maintained to fluctuate within a small range by the model, and the transverse spacing can be approximately considered to be coordinated to be consistent.
In the formula: h is a total of 2 Is the value of the transverse distance between the vehicles after the functional transformation; r is 2 Is a constant.
Since the adjustment target of the lateral distance between the vehicles is 0, unlike the longitudinal distance, it is necessary to change the lateral speed feedback coefficient and the lateral position feedback coefficient between the vehicles, but the larger the coefficient is, the better, but the smaller the coefficient is, the speed of lateral convergence can be made faster.
S203, generating a vehicle formation;
the specific generation of the formation comprises the following steps:
s20301, inputting the number n of the vehicles in the formation 1 Randomly generating a position and a speed of the initial vehicle, wherein the position of the initial randomly generated vehicle needs to be within a specified zone size and to avoid too close proximity between vehicles;
s20302, given the state of the virtual leader: the vertical coordinate of the virtual leader is kept consistent with the size when being generated, the horizontal coordinate is the position of the center line of the lane, and then the formation is carried out at a stable running speed
And assigning to the virtual leader, wherein the motion acceleration of the virtual leader is as follows:
controlling the acceleration to [ -5,3]m/s 2 Within a, and a leader Is subjected to v leader The feedback effect of (2).
S3, selecting the shortest stable running time t of vehicle formation 1 Selecting the shortest stable operation time t 1 Is 1 minute;
s4, limiting L according to ramp distance and limiting t according to shortest stable operation time length 1 Calculating the maximum number n of vehicles that can be combined 2 Therefore, the optimal formation length of the automatic driving vehicle stream running on the expressway is obtained. The method comprises the following specific steps:
s401, setting the number n of vehicles in the vehicle group on the ramp 2 The initial value of (1);
s402, calculating the distance L when the two fleets complete the cooperation and reach the stability 1 As shown in fig. 3. The present invention defines "steady state" as: the speed difference between the vehicles is within 0.3m/s, the distance difference between the vehicle heads is within 0.3m, and the absolute value difference of the acceleration is within 0.1m/s 2 Within. Because the cooperative motion process of the vehicle is a fluctuating process, the right part of the log-normal distribution curve is used for carrying out envelope fitting on the speed change in the fluctuating process, and when the distance between the envelope lines is less than the threshold value of 0.3m/s, the vehicle is considered to have reached a stable state, as shown in fig. 7;
the formula inserted into the right-hand curve of log-normal distribution is:
in the formula: a. b and c are parameters to be solved, and when x = e b When f (x) reaches a peak value, then when x ≧ e b The right curve of the log normal distribution can be taken.
S403, calculating the running distance L under the stable running time 2 As shown in FIG. 4, wherein
S404, calculating the running distance L in the process of fleet decomposition and compilation 3 As shown in FIG. 5, the completion of the de-compilation means that the speed difference of the vehicles in two different fleets is within 0.3m/s, the distance difference between the heads of the vehicles is within 0.3m, and the acceleration is realizedThe absolute value of the degree difference is 0.1m/s 2 Interior, L 3 The calculation of (2) is performed from the time of starting the decompilation to the time of completing the decompilation.
S405, judging L 1 +L 2 +L 3 Whether the length limit L is exceeded;
s406, increasing n by taking '1' as a step length when the number of the n-shaped groups is not reached 2 ；
S407, repeating the step S6 until the last n is obtained 2 At this time n 1 +n 2 The optimal formation length of the automatic driving traffic flow under the restriction of the ramp distance of the expressway is obtained;
s408, drawing the number n of different vehicles by taking time as the horizontal axis of the plane coordinate system and taking the running distance as the vertical axis of the plane coordinate system 2 Lower curve cluster, as shown in fig. 8.
In a preferred embodiment of the present invention, the method comprises the following steps:
s1, obtaining running state parameters of an automatic driving traffic stream running on a highway, wherein the running state parameters comprise the number n of the existing formation vehicles 1 =5, existing formation stable driving speed
The length L = 3km is set at the entrance and exit of the ramp of the expressway;
s2, forming the existing automatic driving fleet by adopting a computer simulation method;
the step S2 specifically includes the following steps:
s201: and (3) performing separate control on the longitudinal and transverse distances between the vehicles, and respectively controlling the transverse distance between the vehicles to be coordinated to 0 and the longitudinal distance to be coordinated to an ideal distance.
S202: the attraction and repulsion model between vehicles needs to be established, the conditions of collision and the like in the cooperative process are avoided, because the longitudinal distance needs to be coordinated to the ideal distance, the attraction-repulsion function of the following formula 2-1 is established, when the longitudinal distance between the vehicles is shorter, the generated impedance is larger, the collision between the vehicles is avoided, when the distance is moderate, the attraction between the vehicles is generated, and when the distance is larger, the mutual influence between the vehicles is avoided. The attractive-repulsive function for the longitudinal spacing between vehicles is:
in the formula: the polyfit function is a self-defined S-shaped function when h is 1 Close to 0, the value is 1, at h 1 This value is 0 near r, as shown in FIG. 2; h is a total of 1 The ratio of the longitudinal distance between the vehicles after the function transformation to the ideal distance after the function transformation; r is constant, r =0.9 is selected.
When the vehicle initially moves, the transverse positions on the lane are not all on the lane center line, and in order to form a complete cooperative queue, the vehicle needs to be coordinated to have a transverse distance of 0, namely the vehicle keeps running at the lane center line position. Therefore, as shown in equation 2-2, the attraction-repulsion function for establishing the lateral distance is such that when the lateral distances between the vehicles are very close, the vehicles do not affect each other, and when the lateral distance is larger in a certain range, the attraction generated is larger, thereby accelerating the cooperation between the vehicles. The transverse spacing of the vehicle is maintained to fluctuate within a small range by the model, and the transverse spacing can be approximately considered to be coordinated to be consistent.
In the formula: h is a total of 2 Is the value of the transverse distance between the vehicles after the functional transformation; r is a radical of hydrogen 2 0.01 is taken.
Since the adjustment target of the lateral distance between the vehicles is 0, unlike the longitudinal distance, the speed feedback coefficient and the position feedback coefficient between the vehicles need to be changed, but the speed of longitudinal convergence can be increased by making the coefficient smaller rather than the larger the better the coefficient is.
S203, generating a vehicle formation;
the concrete steps for generating the formation are as follows:
s20301, inputting the number n of the vehicles in the formation 1 =5, randomly generating position and speed of initial vehicle, where initial is followed byThe position of the vehicle generated by the machine is required to be at a specified area size =100 × 100m 2 And avoid too close proximity between vehicles;
s20301, given the state of the virtual leader: the vertical coordinate of the virtual leader is kept consistent with the size when being generated, the horizontal coordinate is the position of the center line of the lane, and then the formation is carried out at a stable running speed
And assigning to the virtual leader, wherein the motion acceleration of the virtual leader is as follows:
the acceleration is controlled to be [ -5,3 ] by the formula]m/s 2 Within a, and a leader Is subjected to v leader The feedback effect of (2).
S3, selecting the shortest stable operation time t 1 ＝60s；
S4, limiting L and limiting t according to ramp distance constraint and shortest stable operation time 1 Calculating the number n of vehicles capable of being combined 2 Thereby obtaining the optimal formation length of the automatic driving traffic flow running on the expressway.
The step S4 specifically includes the following steps:
s401, setting the number n of vehicles in the vehicle group on the ramp 2 An initial value of = 2;
s402, calculating the distance L when the two fleets complete the cooperation and reach the stability 1 The definition of the invention is stable, namely that the speed difference between vehicles is within 0.3m/s, the distance difference between the vehicle heads is within 0.3m, and the absolute value difference of the acceleration is within 0.1m/s 2 The vehicle cooperative motion process is a fluctuating process, the right part of envelope lines of the log-normal distribution are used for fitting the speed change in the fluctuating process, and when the space between the envelope lines meets the requirement, the stable state is considered to be achieved;
the formula for the right-hand curve inserted into log-normal distribution is:
in the formula: a. b and c are parameters to be solved, and when x is more than or equal to e b The right curve of the log normal distribution can be taken. The solving of the parameters is carried out by data fitting, and corresponding parameters can be obtained by carrying out data fitting on the maximum value in the speed fluctuation process.
S403, calculating the running distance L under the stable running time 2 In which
S404, calculating the running distance L in the process of fleet decomposition and compilation 3 The completion of the solution editing means that the speed difference of the vehicles in two different fleets is within 0.3m/s, the distance difference between the vehicle heads is within 0.3m, and the absolute value of the acceleration difference is within 0.1m/s 2 Within, L 3 The calculation of (2) is performed from the time of starting the decompilation to the time of completing the decompilation.
S405, judging L 1 +L 2 +L 3 Whether the length limit L is exceeded;
s406, increasing n by taking '1' as a step length when the number of the n-shaped groups is not reached 2 ；
S407, repeating the step S406 until the last n is obtained 2 =3, in this case n 1 +n 2 And =8 is the optimal formation length of the automatic driving traffic flow considering the ramp of the expressway.
S408, drawing the number n of different vehicles by taking time (iteration times) as a horizontal axis of a plane coordinate system and taking the running distance as a vertical axis of the plane coordinate system 2 The lower curve cluster.
In the invention, fig. 1 is a vehicle stress analysis diagram in the marshalling and the un-marshalling process, when the longitudinal and transverse distances of the vehicle are not coordinated to be consistent, the influence of the longitudinal and transverse acting force is received, and finally the transverse distance is coordinated to be 0, and the longitudinal distance is coordinated to be an ideal distance. FIG. 5 shows the difference n in the present invention 2 Corresponding driving curve when n 2 Operation distance of whole re-grouping and de-compiling process in time of =2The distance does not reach the ramp spacing constraint limit, and the marshalling is not sufficient; when n is 2 =3, the running distance of the whole re-grouping and de-editing process almost reaches the restriction limit of the ramp distance, and the grouping length reaches the limit; when n is 2 The travel distance of the entire re-grouping and de-coding process at =4 has exceeded the ramp spacing constraint, at which point the grouping length has exceeded the limit.
While the present invention has been described with reference to the particular illustrative embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications, equivalent arrangements, and equivalents thereof, which may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (4)
1. A method for setting an optimal formation length for automatic driving under the constraint of ramp spacing of a highway is characterized by comprising the following steps:
s1, obtaining a distance L between a ramp a and a ramp b of the highway, and obtaining running state parameters of an automatic driving traffic flow of an upstream main line of the ramp a, wherein the running state parameters comprise the number n of the existing formation vehicles 1 The existing formation stable running speed
S2, simulating the marshalling and ungrouping process between the vehicles on the upper ramp and the existing formation vehicles through computer simulation;
the core method in the simulation process is as follows:
s201, separately controlling longitudinal and transverse distances between vehicles, and respectively controlling the transverse distances between the vehicles to be coordinated to 0 and the longitudinal distances to be coordinated to an ideal distance;
s202, establishing a following model among vehicles, avoiding collision in the process of carrying out cooperation, and establishing a following function;
the following function is established as:
three adjacent vehicles are respectively driven according to respective longitudinal directionsThree different longitudinal forces are formed to the spacing
Gradually adjusting the motion of the vehicles by the longitudinal force to coordinate the longitudinal spacing between the vehicles to be consistent, wherein the attraction-repulsion function of the longitudinal spacing between the vehicles is as follows:
in the formula: the polyfit function is a self-defined S-shaped function when h is 1 Close to 0, polyfit (h) 1 ) Is 1 at h 1 R-time poly fit (h) 1 ) Is 0; h is 1 The ratio of the longitudinal distance between the vehicles after the function transformation and the ideal distance after the function transformation is obtained; r is a constant;
three adjacent vehicles are subjected to different transverse forces
The transverse movement of the vehicle is gradually adjusted through the transverse acting force, so that the transverse position of the vehicle is coordinated to the central line of the lane, an attraction-repulsion function of the transverse distance is established,
in the formula: h is 2 The value of the transverse distance between the vehicles after the functional transformation; r is 2 Is a constant;
s203, generating a vehicle formation;
the vehicle formation generation step comprises the following steps:
s20301, inputting the number n of the vehicles in the formation 1 Randomly generating the position and speed of the initial vehicle, wherein the position of the initial randomly generated vehicle is within the designated area size, and avoiding too close proximity between the vehicles;
s20302, giving the state of the virtual leader:the vertical coordinate of the virtual leader is consistent with the size when being generated, the horizontal coordinate is the position of the center line of the lane, and then the formation is carried out at a stable running speed
And assigning to the virtual leader, wherein the motion acceleration of the virtual leader is as follows:
controlling the acceleration to [ -5,3]m/s 2 Within a, and a leader Is subjected to v leader The feedback effect of (c);
s3, selecting the shortest stable running time t of vehicle formation 1 ；
S4, limiting L according to ramp distance and limiting t according to shortest stable operation time length 1 Calculating the maximum number n of vehicles to be combined 2 Obtaining the optimal formation length of the automatic driving traffic stream running on the highway;
the method comprises the following specific steps:
s401, setting the number n of vehicles in the vehicle group on the ramp 2 An initial value of (1);
s402, calculating the distance L when the two fleets complete the cooperation and reach the stability 1 Carrying out envelope fitting on the speed change in the fluctuation process by utilizing the right part of the log-normal distribution curve, and considering that the stable state is achieved when the distance between envelope lines is less than 0.3m/s of a threshold value;
the formula for the right-hand curve inserted into log-normal distribution is:
in the formula: a. b and c are parameters to be solved, and when x = e b When f (x) reaches a peak value, then x ≧ e b Taking a right curve of log-normal distribution;
s403, calculating during stable operationLong travel distance L 2 Wherein
S404, calculating the running distance L in the process of fleet decomposition and compilation 3 The completion of the solution editing means that the speed difference of the vehicles in two different fleets is within 0.3m/s, the distance difference of the vehicle heads is within 0.3m, and the absolute value of the acceleration difference is within 0.1m/s 2 Within, L 3 The calculation of (2) is from the time of starting the decompiling to the time of finishing the decompiling;
s405, judging L 1 +L 2 +L 3 Whether the length limit L is exceeded;
s406, increasing n by taking '1' as a step length when the number of the n-shaped groups is not reached 2 ；
S407, repeating the step S406 until the last n is obtained 2 At this time n 1 +n 2 Namely the optimal formation length of the automatic driving traffic flow under the restriction of the ramp distance of the expressway.
2. The method for setting the optimal formation length for autopilot under the restriction of the inter-ramp distance of the expressway according to claim 1, wherein the expressway inter-ramp comprises an expressway lane, an expressway inter-ramp entrance, and an expressway inter-ramp exit.
3. The method for setting the optimal formation length for automatic driving under the constraint of the ramp distance of the expressway according to claim 1, wherein the time length t for the shortest stable operation of the formation of vehicles is selected in the step S3 1 It was 1 minute.
4. The method for setting the optimal formation length for automatic driving under the constraint of the ramp distance of the expressway according to claim 1, wherein the step S4 further comprises the following steps: the horizontal axis of the plane coordinate system is taken as time, the vertical axis of the plane coordinate system is taken as travel distance, and the number n of different vehicles is plotted 2 The lower curve cluster.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210061844.1A CN114495556B (en) | 2022-01-19 | 2022-01-19 | Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210061844.1A CN114495556B (en) | 2022-01-19 | 2022-01-19 | Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114495556A CN114495556A (en) | 2022-05-13 |
| CN114495556B true CN114495556B (en) | 2023-03-10 |
Family
ID=81472082
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210061844.1A Active CN114495556B (en) | 2022-01-19 | 2022-01-19 | Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114495556B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102017221104A1 (en) * | 2017-11-24 | 2019-05-29 | Robert Bosch Gmbh | Method for coordinating distances within a vehicle association |
| CN110070707A (en) * | 2019-05-16 | 2019-07-30 | 吴鼎新 | A method of realizing that cooperating type adaptive learning algorithms fleet forms a team and separates |
| CN111554081A (en) * | 2020-03-30 | 2020-08-18 | 江苏大学 | Multi-level leader pigeon group theory-based fleet intersection obstacle avoidance control method |
| CN113808436A (en) * | 2021-08-31 | 2021-12-17 | 东南大学 | Motorcade control method for off-ramp vehicles to leave intelligent internet dedicated lane |
-
2022
- 2022-01-19 CN CN202210061844.1A patent/CN114495556B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102017221104A1 (en) * | 2017-11-24 | 2019-05-29 | Robert Bosch Gmbh | Method for coordinating distances within a vehicle association |
| CN110070707A (en) * | 2019-05-16 | 2019-07-30 | 吴鼎新 | A method of realizing that cooperating type adaptive learning algorithms fleet forms a team and separates |
| CN111554081A (en) * | 2020-03-30 | 2020-08-18 | 江苏大学 | Multi-level leader pigeon group theory-based fleet intersection obstacle avoidance control method |
| CN113808436A (en) * | 2021-08-31 | 2021-12-17 | 东南大学 | Motorcade control method for off-ramp vehicles to leave intelligent internet dedicated lane |
Non-Patent Citations (1)
| Title |
|---|
| 高速公路网的匝道协调控制及仿真研究;嵇春宝等;《系统仿真学报》;20090220(第04期);第1206-1209页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114495556A (en) | 2022-05-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | A review on cooperative adaptive cruise control (CACC) systems: Architectures, controls, and applications | |
| CN110928295B (en) | Robot path planning method integrating artificial potential field and logarithmic ant colony algorithm | |
| CN108806252B (en) | A kind of Mixed Freeway Traffic Flows collaboration optimal control method | |
| EP3730370A1 (en) | Method and device for acquiring automatic driving track | |
| CN111238521A (en) | Path planning method and system for unmanned vehicle | |
| CN113489793B (en) | Expressway double-lane cooperative control method in mixed traffic scene | |
| CN103092949B (en) | A kind of identification of compound crossing in Floating Car Trace Formation and construction method | |
| US20220351625A1 (en) | Dynamic platoon formation method under mixed autonomous vehicles flow | |
| CN113489531B (en) | Unmanned aerial vehicle cooperative communication method for joint optimization of power and three-dimensional trajectory | |
| CN112907950B (en) | Cellular transmission model improvement method for vehicle-road cooperative environment | |
| CN114842644B (en) | Traffic capacity calculation method for mixed traffic flow intersection area | |
| CN114613142B (en) | Rule-based automatic driving intersection vehicle lane change control method | |
| CN111325967A (en) | Intelligent networking automobile formation control method and device based on cooperative assignment | |
| CN110084355B (en) | Grid scale optimization method of large-amount interaction particle motion simulation system | |
| CN114889603A (en) | Vehicle lane changing processing method and device | |
| CN114283576B (en) | Vehicle intention prediction method and related device | |
| CN113409598A (en) | Cooperative linkage self-adaptive timing method and device for regional road traffic signal lamps | |
| CN114495556B (en) | Method for setting optimal formation length for automatic driving under constraint of ramp spacing of highway | |
| CN113593228A (en) | Automatic driving cooperative control method for bottleneck area of expressway | |
| Min et al. | A novel on-ramp merging strategy for connected and automated vehicles based on game theory | |
| CN113657433A (en) | Multi-mode prediction method for vehicle track | |
| Caruntu et al. | Connected cooperative control for multiple-lane automated vehicle flocking on highway scenarios | |
| Phan et al. | A cooperative space distribution method for autonomous vehicles at a lane-drop bottleneck on multi-lane freeways | |
| CN115092141B (en) | Track planning method and equipment applied to lane-changing overtaking of automatic driving vehicle | |
| CN115938118A (en) | No-signal intersection vehicle speed dynamic planning method based on road side guidance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |