JP2013164758A - Control device for vehicles travelling in line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for vehicles travelling in line with which to prevent multiple groups of vehicles from forming one vehicle group consisting of a large number of vehicles travelling in line and avoid the occurrence of congestion.SOLUTION: When a vehicle group having a vehicle density higher than a recommended vehicle density exists, a command is provided to a vehicle group behind the previously mentioned vehicle group so that the target vehicle density of the vehicle group at the back becomes equal to the recommended vehicle density. Moreover, when the vehicle density of a vehicle group at a bottleneck is lower than a recommended vehicle density, the vehicle density of the vehicle group at the bottleneck is deemed as the target vehicle density of a vehicle group behind the vehicle group at the bottleneck.

Description

  The present invention relates to a platooning control apparatus adapted to avoid traffic jams.

  Traffic congestion is a major problem on expressways and motorways. In particular, traffic jams are likely to occur at bottleneck portions such as lane decreasing portions, tunnel entrances, uphill entrances, and sharp curve entrances. Japanese Patent Application Laid-Open No. 2004-133620 proposes that commands are given to individual vehicles so that the speed and the inter-vehicle distance at which the traffic flow is maximized before reaching the bottleneck portion.

JP 2011-31768 A

  By the way, the occurrence of traffic jams occurs when a vehicle in a bottleneck portion is greatly decelerated while a large number of vehicles are running in succession. If it is propagated and the vehicle closest to the rear (upstream side) is extreme, it will stop. If the number of vehicles traveling in a row is small, even if the leading vehicle decelerates significantly, for example, at the bottleneck, the effect is that only a few rear vehicles decelerate, and no congestion will occur. Become. As described in Patent Document 1, even if the speed and distance between vehicles are controlled for each vehicle, there are limits to avoid congestion at the bottleneck when a large number of vehicles are running continuously. is there.

  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to provide a platooning control device that can more reliably avoid a traffic jam caused by a large number of vehicles traveling in series. It is to provide.

  In order to achieve the above object, the present invention basically grasps a state in which a plurality of vehicles are running in a row as one vehicle group, and the vehicle density (travel per unit distance) of this vehicle group. The number of vehicles is controlled in a direction that falls within a range where traffic congestion can be avoided. Specifically, when the vehicle density of a certain vehicle group becomes higher than the recommended vehicle density, the target vehicle density of the vehicle group behind the vehicle group is controlled in a direction to achieve the recommended vehicle density. According to the present invention, when one vehicle group has a large vehicle density that increases the possibility of congestion, the vehicle density of the rear vehicle group is set to the recommended vehicle density, so that the vehicle A situation in which a rear vehicle group is linked to a high-density front vehicle group and gathers into one large vehicle group is prevented in advance, and traffic congestion is avoided.

  Preferred embodiments of the present invention are as follows. That is, when the vehicle density of the vehicle group in the bottleneck portion is less than the recommended vehicle density, the vehicle density of the vehicle group in the bottleneck portion can be set as the target vehicle density of the rear vehicle group (invoice). Item 2). In this case, when the vehicle group that was behind passes through the bottleneck portion, the vehicle density does not increase greatly (that is, without causing traffic jam), which is preferable for smoothly passing the bottleneck portion. Become.

  The target vehicle density of the vehicle group behind the bottleneck portion can be set to be equal to or less than the traffic capacity that can pass through the bottleneck portion without changing the vehicle density (corresponding to claim 3). In this case, the passage of the bottleneck portion can be performed within the range of the traffic capacity of the bottleneck portion, which is preferable in preventing a situation in which a vehicle that cannot be swept away by the bottleneck portion overflows backward.

  When the vehicle density of the vehicle group behind the bottleneck portion is high, the vehicle group passing through the bottleneck portion can be controlled so that the distance from the vehicle group in front of the vehicle group becomes small. ). In this case, the space in front of the vehicle group is effectively used to prevent the rear vehicle group from joining the vehicle group passing through the bottleneck portion and forming a large single vehicle group. This is preferable.

  According to the present invention, it is possible to prevent an excessive increase in the number of vehicles included in one vehicle group and effectively avoid traffic jams.

The block diagram which shows the example of a control system of this invention. The figure which shows distribution of a traffic jam phase, a free phase, and a metastable phase when traffic volume and average speed are used as parameters. The figure explaining a mode that a traffic jam occurs and a mode that a traffic jam is avoided. The figure explaining the specific example for setting it as a target vehicle density. The flowchart which shows the example of control of this invention. The figure which shows the case where it is set as the vehicle density according to the traffic volume of the bottleneck part about the vehicle group before a bottleneck part while showing the state where the traffic volume overflowed in the bottleneck part. The figure which shows the example which adjusts a vehicle density so that the traffic volume of a bottleneck part may not be exceeded.

  In FIG. 1, an ACC device (automatic constant speed traveling device) 1 in a vehicle (automobile) is shown as a portion surrounded by a broken line. The ACC device 1 includes a controller (control unit) U configured using a microcomputer, and units S1 to S8 that are input to or output from the controller U. S <b> 1 is an operation unit that performs power ON / OFF of the ACC device 1, selection of ACC control, a return instruction when ACC control is temporarily interrupted, and selection of congestion avoidance travel described later. . S2 is a target vehicle speed input unit for inputting the target vehicle speed. S3 is a target inter-vehicle input unit that inputs the target inter-vehicle distance (separation distance from the preceding vehicle). S4 is a display unit that displays the current setting status of the ACC device 1. S5 is a vehicle operation unit including an accelerator and a brake, and outputs an operation signal to the controller U when the accelerator is operated or when the brake is operated. S6 is a motion measurement unit that measures, for example, the acceleration / deceleration and yaw rate of the vehicle. S7 is a vehicle control unit that serves as an accelerator and a brake (automatic accelerator, automatic brake). S8 is an inter-vehicle distance measuring unit that measures the inter-vehicle distance from the preceding vehicle (for example, constituted by a ray or the like).

  When the target vehicle speed is input, the controller U controls the vehicle control unit S7 so as to maintain the target vehicle speed. Further, when the target inter-vehicle distance is input, the controller U controls the vehicle control unit S7 so that the distance from the preceding vehicle measured by the inter-vehicle distance measurement unit S8 becomes the target inter-vehicle distance. Furthermore, when both the target vehicle speed and the target inter-vehicle distance are input, the controller U controls the vehicle control unit S7 such that the inter-vehicle distance does not become smaller than the target inter-vehicle distance and becomes the target vehicle speed. If the driver operates the accelerator or the brake (when a signal is input from the vehicle driving steering unit S5) while controlling the target vehicle speed or the target inter-vehicle distance, the controller U When the control and the control for the target inter-vehicle distance are interrupted and a control return command is received from the operation unit S1 while the control is interrupted, the control for setting the target vehicle speed or the target inter-vehicle distance starts again (control return). In addition, since the control content itself of the ACC apparatus 1 as described above is the same as the conventional one, further explanation is omitted. Note that, when the traffic jam avoidance travel is selected in the operation unit S1, the traffic jam avoidance travel described later is used instead of the above-described normal ACC control (automatic deceleration or automatic acceleration is performed for traffic jam avoidance). ).

  A control signal from, for example, a traffic control center TC provided outside the vehicle is input to the controller U (the vehicle and the traffic control center TC exchange signals by, for example, road-to-vehicle communication). The control signal from the traffic control center TC is calculated by the calculation unit 11 and corresponds to the target vehicle density as will be described later. In the embodiment, the target deceleration (may be the target acceleration). And the deceleration (acceleration) end point. In order to confirm the deceleration end point, a GPS signal (vehicle position signal) is input to the controller U (not shown). Note that instead of the deceleration end point, the deceleration end time can be used, and in this case, the GPS signal is not necessary.

  In order to calculate the target deceleration and the deceleration end point, the traffic control center TC includes three vehicle density calculation units 12 to 14. The calculation unit 12 calculates the vehicle density of the vehicle group passing through the bottleneck portion. The calculation unit 13 calculates the vehicle density of the vehicle group including the host vehicle. The calculation part 14 calculates the vehicle density of the vehicle group behind the vehicle group to which the host vehicle belongs.

  The vehicle density will be described with reference to FIG. First, the vehicle density is the number of traveling vehicles per unit distance (for example, 1 km) for one traveling lane. In order to calculate the vehicle density, vehicle detectors (traffic counters) 22A, 22B, 22C,... Are provided for each predetermined distance (for example, every 1 km) on the road (highway, exclusive road for automobiles) 21. Yes. The traffic control center TC counts the number of vehicles passing through each of the vehicle detectors 22A, 22B, 22C... And calculates the number of vehicles (that is, vehicle density) between adjacent vehicle detectors. In FIG. 3, the vehicle sensor 22A is provided in the bottleneck portion, the vehicle detector 22B is provided in front of the bottleneck portion, and 22C is provided in front of the bottleneck portion.

  In FIG. 3A, the vehicle group between the vehicle detectors 22A and 22B is shown as C1, and the vehicles included in this vehicle group C1 are shown as C11, C12, C13, and C14 from the head side. Similarly, a vehicle group between the vehicle detectors 22B and 22C is shown as C2, and vehicles included in the vehicle group C2 are shown as C21, C22, C23, and C24 from the head side. Further, a vehicle group upstream of the vehicle detector 22C is indicated as C3, and vehicles included in the vehicle group C3 are indicated as C31 and C32 from the head side. In FIG. 3, the number of vehicles included in each vehicle group is illustrated to be small, but actually, for example, a vehicle including many vehicles such as 10 to 60 is assumed. More specifically, when the vehicle density is 70 units / km, it becomes a factor that causes a traffic jam with a slight trigger. For this reason, the vehicle density in one vehicle group is, for example, less than 70 units as described later. Vehicle density control is performed at the same time.

  In the state of FIG. 3A, the rearmost vehicle C24 of the vehicle group C2 is in a state where the distance between the last vehicle C24 and the vehicle C23 immediately before is large, while the distance between the vehicle C31 of the vehicle group C3 is small. It has become. As shown in FIG. 3C, when the vehicle density control is not executed, the rear vehicle travels closer to the front vehicle, and the time elapses from the state of FIG. When the leading vehicle in the vehicle group C2 reaches the vehicle detector 22A, the distance between the vehicles C23 and C24 is reduced, and the leading vehicle C31 in the vehicle group C3 that is the rear vehicle group immediately behind the vehicle C24. And the following vehicle C32 will continue in a state where the intervals are clogged. That is, if nothing is done from the state of FIG. 3 (A), the vehicle group C2 and the vehicle group C3 will be assembled into one vehicle group.

  On the other hand, by instructing the leading vehicle C31 of the vehicle group C3 to maintain a certain vehicle density from the traffic control center TC, the ACC device 1 of the vehicle C31 operates according to this command, so that FIG. As shown in (2), a large inter-vehicle distance from the front vehicle group C2 is secured. That is, the free-running vehicle C24 approaches the vehicle C23 immediately before it, but the vehicle C31 maintains a large inter-vehicle distance from the vehicle C24, and the vehicle group C2 and the vehicle group C3 are largely separated from each other. Secured. Note that the vehicle C32 behind the vehicle C31 is decelerated as the vehicle C31 decelerates and maintains the vehicle group C3. In other words, when some vehicles in a certain vehicle group decelerate, for example, the subsequent vehicles also decelerate, and even if all the vehicles in a certain vehicle group are not controlled by the present invention, (Some of the free-running vehicles may catch up with the front car group, or conversely with the rear car group, It does not lead to confluence).

  In this way, the situation in which the rear vehicle group approaches the front vehicle group and gathers into one vehicle group is prevented, and this results in the vehicle density of one vehicle group becoming too large. The occurrence of traffic congestion is prevented. In particular, when a vehicle group having an extremely high vehicle density (for example, 70 cars / km) reaches the bottleneck portion, the possibility of occurrence of traffic congestion at the bottleneck portion is extremely high. By limiting the number of vehicles included in one vehicle group (the vehicle density is set to a predetermined threshold value or less), occurrence of such a traffic jam is prevented.

  Fig. 2 shows a free phase that allows smooth running with traffic volume and average speed as parameters, a traffic phase where traffic jams occur, and a meta-stable system that has a very high possibility of traffic jams even before traffic jams occur. The distribution with the phase is shown. In FIG. 2, the straight line that rises to the right through the origin is the coastal density line, and a traffic jam phase occurs in a region on the right side of the coastal density line (particularly in the lower right region). A characteristic line passing through the origin and located slightly to the left of the coastal density line is a recommended density line. Traffic congestion can be avoided by controlling the vehicle density so that the vehicle density is on the left side of the recommended density line. Although it is possible to make the vehicle density sufficiently smaller than the recommended vehicle density, in this case the driving amount per unit time will decrease, so it is recommended to satisfy both traffic avoidance and traffic volume securing. It is ideal to run at vehicle density.

  In FIG. 2, the vehicle head time is shown. The vehicle head time is the time from when the preceding vehicle passes through a specific point until the next vehicle passes through this specific point, as is known. The larger (longer), the smoother the ride. 3 indicates the average speed and the average vehicle density at the bottleneck portion, and the average vehicle head time at the circle portion is as small as about 2 seconds. Further, a straight line connecting the origin and the above-mentioned ◯ mark is shown as a BN density line, and the recommended vehicle density is set to be slightly smaller than the BN density line. The data as shown in FIG. 2 is stored in the traffic control center TC as a database for each road (bottleneck portion).

  2 indicates an intersection of the average speed at the bottleneck portion and the recommended vehicle density, and the average vehicle head time at the intersection portion becomes a target average vehicle head time for setting the vehicle density to the recommended vehicle density. In FIG. 2, the Δ mark indicates that the vehicle density is sufficiently smaller than the recommended vehicle density, but when the traffic volume behind the vehicle is large, the vehicle density approaches the recommended vehicle density so that the distance from the rear vehicle group is increased. This is preferable in order to prevent the subsequent traffic congestion.

  Next, with reference to FIG. 4, a control example in which the vehicle C31 is focused and the vehicle group ahead (the last vehicle C24) does not gather (ensure a sufficient inter-vehicle distance) will be described. Although FIG. 4 corresponds to that in FIG. 3A, the number of vehicles in the vehicle group C2 is one more than in the case of FIG. 3A, and the leading vehicle is indicated by C20. Note that the vehicle C24 travels freely and approaches the vehicle ahead.

First, the current speed of the leading vehicle C31 of the vehicle group C3 is set to _Vcur . The distance between the adjacent vehicle detectors 22B and 22C is set to L0. Further, a distance obtained by multiplying the vehicle head time with the leading vehicle C20 of the vehicle group C2 by the average speed is set as a distance L1 to the leading vehicle C20. The time T1 until the leading vehicle C20 of the vehicle group C2 reaches the bottleneck portion (vehicle detector 22A) is defined as “(L0−L1) / average speed of the vehicle group C2”. Further, when the leading vehicle C20 of the vehicle group C2 reaches the bottleneck portion (vehicle detector 22A), a value obtained by multiplying the target average vehicle head time of the vehicle group C2 by the number of vehicles passing (the number of vehicle groups C2) is a distance L2. It is said. In order for the leading vehicle C30 of the vehicle group C3 to reach the front position at a distance L2 from the bottleneck portion (vehicle sensor 22A) when the time T1 has elapsed, the following is shown from the bottleneck portion to the front position by a distance L2: What is necessary is just to decelerate at a deceleration _Atg (which may be an acceleration) that satisfies the condition of the equation (1). Note that L _tgt = deceleration distance = L0−L2 (also set as a deceleration end point), and T _tgt = deceleration time = T1.

L _tgt = V _cur × T _tgt + A _tgt × T _tgt × T _tgt / 2

It is only necessary to calculate the target deceleration _tgt that satisfies the above relationship and control the vehicle C31 so that the target deceleration _Atg is obtained (congestion avoidance control in the ACC device 1 in the vehicle C31). Execution). However, when the target acceleration / deceleration _Atg is smaller than the minimum value A _limit , it is preferable to set Atgt to A _limit in order to break the slight acceleration / deceleration (to increase sharpness). By changing the speed of the vehicle C31 with the target acceleration / deceleration _tgt during the deceleration time T1 set as described above, it is possible to prevent the vehicle C31 from approaching the vehicle C24.

  FIG. 5 is a flowchart for performing the control described in FIG. 4, and this flowchart will be described below. In the following description, Q indicates a step. Further, the control in FIG. 5 (the control described in FIG. 4) is based on the assumption that the traffic avoiding travel is selected in the operation unit S1 in FIG. Furthermore, in the following control, it becomes control about the own vehicle (equivalent to the vehicle C31 of FIG. 4).

  Based on the above, in Q1, the vehicle density and average speed are calculated for the vehicle group that passes through the bottleneck portion, the vehicle group to which the host vehicle belongs, and the vehicle group to which the host vehicle belongs. .

After Q1, in Q2, it is determined whether or not the vehicle density of the vehicle group that passes through the bottleneck portion is higher than the recommended vehicle density. When the determination in Q2 is YES, in Q3, a recommended vehicle density (a vehicle density that can avoid traffic congestion while increasing the traffic capacity as much as possible) is set as the target vehicle density. Thereafter, in Q4, the target average vehicle head time is calculated (reading based on the data shown in FIG. 2). Thereafter, in Q5, the target deceleration (A _tgt described above) and the deceleration end point (position L2 before the bottleneck portion) are calculated. Information regarding the target deceleration and deceleration end point calculated in Q5 is input to the ACC device 1 of the host vehicle, and the host vehicle is decelerated according to the input information.

  When the determination in Q2 is NO, in Q6, the vehicle density of the bottleneck portion is set as the target vehicle density. Thereafter, the process proceeds to Q4. By setting the vehicle density of the bottleneck portion to the target vehicle density as in Q6, when the host vehicle reaches the bottleneck portion, the bottleneck portion can pass smoothly.

  FIG. 6 shows a situation where the vehicle density exceeds the traffic volume (traffic capacity) of the bottleneck portion in the bottleneck portion. That is, in the bottleneck portion, the portion exceeding the traffic volume (shown with hatching) cannot be fully judged, so the vehicle train becomes longer (extended) rearward. When the traffic volume overflows in the bottleneck area, the vehicle density can be adjusted in advance so that the vehicle volume behind it is less than the traffic volume at the bottleneck area. When the vehicle group passes through the bottleneck portion, the vehicle train can pass while maintaining the same speed without being lengthened.

  FIG. 7 shows that the traffic volume is reduced in advance by controlling the vehicle group having a high vehicle density so as to reduce the vehicle density. The hatched part in FIG. 7 is the amount exceeding the traffic volume of the bottleneck. In this case, if there is enough space in front of the vehicle group, adjust the front vehicle and nearby vehicles by instructing them to accelerate and shifting the excess traffic that cannot be handled at the bottleneck to the front. can do. On the contrary, when there is a margin space behind, it can be adjusted by instructing the vehicle in the rear part of the vehicle group to decelerate and shifting the excess traffic volume that cannot be determined to the rear side.

  Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . The function of the calculation unit 11 illustrated in FIG. 1 may be provided on the vehicle side. The management as a vehicle group can be set to a certain number (for example, 10) or more, and the number of vehicles less than this can be excluded from the control target (the possibility of occurrence of traffic congestion is extremely low, and control is simplified) ). The distinction between a certain vehicle group and an adjacent vehicle group can be made on condition that the vehicle is separated by a predetermined distance or more or a predetermined vehicle head time. For example, it is possible to control to divide one vehicle group into two vehicle groups by decelerating the vehicle on the rear side of the vehicle group, for example, at the middle part (divided into three or more vehicle groups). Can also do). Information for traffic congestion avoidance control related to the vehicle density may be notified by display or voice to a vehicle that does not have the ACC device 1, or may be notified by display on a road sign. . Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferable or expressed as an advantage, and the present invention is understood as a control method. It is also possible.

  The present invention is effective as a technique for avoiding traffic jams.

1: ACC devices C1 to C3: Vehicle group C31: Own vehicle (belonging to vehicle group C3)
S7: Vehicle control unit (speed change)
11: Target deceleration, deceleration end point calculation units 12-14: Vehicle density calculation units 22A-22C: Vehicle detector (for vehicle density detection)
U: Controller

Claims (4)

Vehicle density detection means for detecting vehicle density in a plurality of vehicle groups on the road;
Comparison means for comparing the vehicle density detected by the vehicle density detection means with the recommended vehicle density;
Control means for issuing a command to the vehicle group so that the vehicle density of the vehicle group becomes a target vehicle density;
With
As a result of the comparison by the comparison means, when there is a vehicle group having a vehicle density greater than the recommended vehicle density, the control means sets the vehicle group behind the vehicle group having a vehicle density greater than the recommended vehicle density. On the other hand, the target vehicle density is commanded as the recommended vehicle density.
A row running control device characterized by that. In claim 1,
When the vehicle density of the vehicle group passing through the bottleneck portion is less than the recommended vehicle density as a result of the comparison by the comparison means, the control means is configured to control the vehicle group behind the vehicle group passing through the bottleneck portion. A convoy travel control device that issues a command to set the vehicle density of a vehicle group passing through the bottleneck portion as a target vehicle density. In claim 1,
When the vehicle density of the vehicle group that passes through the bottleneck portion is less than the recommended vehicle density as a result of the comparison by the comparison means, the control means sets the target vehicle for the vehicle group behind the vehicle group that passes through the bottleneck portion. A convoy travel control device, characterized in that, as a density, a command is given to make the vehicle density equal to or less than a traffic capacity that can pass without fluctuation in the vehicle density passing through the bottleneck portion. In claim 2 or claim 3,
When the vehicle density of the vehicle group behind the bottleneck portion is large, the vehicle group passing through the bottleneck portion is instructed to target vehicle density for reducing the distance from the vehicle group in front of the vehicle group. A convoy travel control device.

Images