Signal control system

Abstract

The invention provides a signal control system and a novel method for realizing signal control of an intersection where an automatic driving automobile runs. A signal control system performs signal control of a predetermined intersection in a road network on which an automatic driving vehicle travels. On the basis of travel information received from the vehicles, the signal control system determines, in the permitted entry direction, a group of vehicles composed of one or more vehicles that are scheduled to enter the intersection from the same permitted entry direction, and determines a predetermined arrival time of the group of vehicles that is scheduled to arrive at the intersection. The signal control system sets, on a given time axis, a unique permitted entry direction and a permitted entry period for permitting entry into the intersection for each vehicle group, and processes all the permitted entry directions as stop signals during periods other than the permitted entry period, thereby managing signals in accordance with the elapse of time. The signal control system generates signal management information based on the management content and notifies the vehicle of the signal management information.

Description

Technical Field

[0001] The invention relates to a signal control system for an intersection. Background Art

[0002] Traffic signal control is performed at intersections, and the traffic signal control is to control the operation of a signal light for the purpose of ensuring a smooth traffic flow. As one of the traffic signal controls, priority control is known, which changes signal control parameters to allow specific vehicles such as public vehicles such as line buses to pass first (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-115123 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In recent years, the automatic driving technology of cars that can drive autonomously is being developed. At the intersection where the automatic driving car is driving, in order for the car to recognize the information of the traffic signal related to the intersection, it is desired that there is a means to notify the car of the traffic signal information in addition to the traffic lights that are conventionally installed at the intersection. In addition, the automatic driving of the car has the following characteristics: the driving direction, driving speed, etc. can be controlled without the help of human hands. In the case where all the cars passing through the intersection are automatic driving cars, if a new signal control that can pass through the intersection more smoothly and efficiently than before can be implemented, it will be very convenient and also very meaningful for the popularization of automatic driving cars.

[0008] The problem to be solved by the present invention is to provide a new method for signal control at an intersection where an autonomous driving car is traveling.

[0009] Solutions for solving problems

[0010] The first invention for solving the above-mentioned problem is a signal control system for controlling the signal at a predetermined intersection where an autonomously driven car travels.

[0011] The vehicle comprises: a communication control device that communicates with the signal control system; and an entry control device that performs entry control into the intersection based on given signal management information received from the signal control system.

[0012] The signal control system comprises:

[0013] a driving information acquisition unit, which acquires driving information from the vehicle;

[0014] a determination unit that determines, based on the travel information, a vehicle group consisting of one or more vehicles scheduled to enter the intersection from the same permitted entry direction, and determines a scheduled arrival time of the vehicle group at the intersection;

[0015] a signal management unit that sets a unique permitted entry direction and permitted entry period for each vehicle group to enter the intersection on a given time axis based on the determination result of the determination unit, and treats all permitted entry directions as stop signals during a period other than the permitted entry period, thereby managing the signal in accordance with the passage of time; and

[0016] A notification control unit generates the signal management information based on the management content of the signal management unit and performs control to notify the vehicle.

[0017] According to the first invention, a new method for signal control of an intersection where an autonomous driving car travels can be provided. That is, a completely new signal control of an intersection is performed as follows: each vehicle group that enters the intersection from the same permitted entry direction is set on a given time axis as the only permitted entry direction and permitted entry period allowed to enter, and all permitted entry directions are treated as stop signals for the period other than the permitted entry period. Since the permitted direction allowed to enter the intersection is limited to at most one permitted direction and the car enters the intersection in units of vehicle groups, it is possible to avoid the intersection of the driving directions between cars, and to suppress congestion to achieve a smooth and efficient traffic flow. Moreover, the signal management information based on the management content of the signal at the intersection is notified to each car, so that the autonomous driving car can perform entry control into the intersection according to the set permitted permitted entry direction and permitted entry period.

[0018] The second invention is the following signal control system: in the above invention,

[0019] The signal management unit sets the permitted entry period by using the permitted entry direction of the vehicle group as the permitted permitted entry direction so that the permitted entry periods of the vehicle groups do not overlap.

[0020] The notification control unit includes information on the entry permission period set for the vehicle group in the signal management information and notifies the vehicle group.

[0021] According to the second invention, the entry permission periods of each vehicle group are set so as not to overlap. Thus, it is possible to perform so-called occupied entry signal control to the intersection in units of vehicle groups.

[0022] The third invention is the following signal control system: in the above invention,

[0023] The signal management unit assigns the allowed entry period in order from the vehicle group having the earlier scheduled arrival time, thereby setting the allowed entry period on the time axis.

[0024] According to the third invention, the allowed entry period is set by allocating in order from the vehicle group that is scheduled to arrive at the intersection earlier than the scheduled arrival time. Thus, the allowed entry period is allocated in the order of arrival at the intersection from early to late, so that the following signal control can be performed: the time that each car stops after arriving at the intersection and cannot enter is shortened, thereby suppressing congestion at the intersection.

[0025] The fourth invention is the following signal control system: in the above invention,

[0026] The determination unit determines, for each of the vehicle groups, an ideal passage period of the intersection starting from the scheduled arrival time based on the travel information,

[0027] The signal management unit sets the entry permission period for each of the vehicle groups based on the ideal passage period.

[0028] According to the fourth invention, an ideal passing period starting from the scheduled arrival time is determined, and the entry permission period is set based on the ideal passing period. The ideal passing period can be set as a period that allows the vehicle group to enter and pass through the intersection without stopping in front of the intersection. Thus, based on the ideal passing period, the following signal control can be performed: the time that each car stops after arriving at the intersection and cannot enter is shortened, thereby suppressing congestion at the intersection.

[0029] A fifth invention is the following signal control system: in the above invention,

[0030] When there are the vehicle groups whose ideal passage periods overlap, the signal management unit divides the ideal passage periods of one or both overlapping vehicle groups and sets the entry permission periods corresponding to the divided ideal passage periods.

[0031] According to the fifth invention, the ideal passing period of one or both overlapping vehicle groups is divided, and the allowed entry period corresponding to the divided ideal passing period is set. In the case where the number of vehicles constituting the vehicle group is large and the duration of the ideal passing period is long, for other vehicle groups with overlapping ideal passing periods, the time they cannot enter and stop after arriving at the intersection becomes longer. In such a case, by dividing the overlapping ideal passing periods between vehicle groups, the allowed entry period can be set in a manner that is alternately allocated between vehicle groups, thereby enabling the following signal control: reducing the deviation of the time between vehicle groups that cannot enter and stop after arriving at the intersection to reduce the sense of unfairness, and suppressing congestion at the intersection.

[0032] The sixth invention is a signal control system as follows: in the above invention,

[0033] The signal management unit makes the ideal passage period or the allowed entry period after division to be a predetermined minimum time length or longer than the predetermined minimum time length.

[0034] According to the sixth invention, the ideal passing period or the allowed entry period is set to a prescribed minimum time or longer than the prescribed minimum time. Thus, the following signal control can be performed: a minimum time or a time longer than the minimum time is ensured as the time for the vehicle group to enter and pass through the intersection, thereby ensuring the safety of the intersection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is an application example of a signal control system.

[0036] Figure 2 This is a diagram illustrating signal control at an intersection.

[0037] Figure 3 This is a diagram for explaining the settings for access permission.

[0038] Figure 4 This is a diagram for explaining the settings for access permission.

[0039] Figure 5 This is a diagram for explaining the settings for access permission.

[0040] Figure 6 This is a diagram for explaining the settings for access permission.

[0041] Figure 7 This is a diagram for explaining the settings for access permission.

[0042] Figure 8 This is a diagram for explaining the settings for access permission.

[0043] Fig. 9 This is a diagram for explaining the settings for access permission.

[0044] Fig.10 This is a diagram for explaining the settings for access permission.

[0045] Fig.11 This is an example of the functional structure of a signal control system.

[0046] Fig.12 This is an example of data that is scheduled to be entered into the vehicle group.

[0047] Fig.13 This is an example of entry permission setting data.

[0048] Fig.14 It is a flow chart of signal control processing. DETAILED DESCRIPTION

[0049] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the mode in which the present invention can be applied is not limited to the following embodiments. In addition, in the description of the accompanying drawings, the same reference numerals are given to the same elements.

[0050] [Signal control system]

[0051] Figure 1 1 is a diagram showing an application example of a signal control system 1 in the present embodiment. The signal control system 1 in the present embodiment is a system that performs signal control at a predetermined intersection in a road network on which an autonomously driven car travels. The signal control system 1 performs signal control at the intersection by communicating with a car 10 traveling on the road via a wireless base station 3, and the wireless base station 3 is installed in various locations so that the entire road network to be controlled is included in the communication range.

[0052] Specifically, the signal control system 1 receives the driving information 32 from each automobile 10. The driving information 32 is information related to the driving of the automobile 10, and includes the driving position, driving speed, driving direction, etc. corresponding to the automobile ID of the automobile 10. The latest information of the driving information 32 is generated and transmitted in the automobile 10 at a predetermined time interval.

[0053] The signal control system 1 sets a unique permitted entry direction and permitted entry period for allowing entry into the intersection based on the received driving information 32 of each automobile 10, and treats all permitted entry directions as stop signals during the period other than the permitted entry period, thereby managing the signal at the intersection. Then, signal management information 34 based on the management content of the signal is generated and notified to each automobile 10. The signal management information 34 is information related to the entry permission for the automobile 10 to enter the intersection, which is generated for each automobile 10, and includes the intersection ID of the intersection, the permitted direction for allowing entry into the intersection, i.e., the permitted entry direction, and the period for allowing entry into the intersection, i.e., the permitted entry period, corresponding to the automobile ID of the automobile 10.

[0054] The automobile 10 is equipped with a communication control device 12 that wirelessly communicates with the signal control system 1 via a wireless base station 3, and a driving control device 14 having a driving control function based on automatic driving. The functions of the driving control device 14 include a function of performing entry control into an intersection based on the signal management information 34 received from the signal control system 1. Specifically, as an entry control, when the driving direction of the vehicle is consistent with the permitted entry direction and is within the permitted entry period, the driving is controlled in a manner of entering the intersection from the permitted direction. When the driving direction is inconsistent with the permitted entry direction or is outside the permitted entry period, the driving is controlled in a manner of not entering the intersection. That is, the driving control device 14 can also be called an entry control device that performs entry control into the intersection based on the signal management information 34 received from the signal control system 1. In addition, in the present embodiment, the driving control function of the driving control device 14 includes a known function of realizing driving control such as preventing collisions and maintaining vehicle spacing by performing image recognition on other driving vehicles based on the captured images captured by the vehicle-mounted camera. In the present embodiment, it is described assuming that a predetermined travel route is preset in the travel control device 14 and the travel control device 14 controls the travel of the host vehicle (automobile 10 ) along the predetermined travel route.

[0055] [Signal control at intersections]

[0056] Figure 2 1 is a diagram for explaining the signal control of an intersection by the signal control system 1. Figure 2An example of an intersection with four permitted entry directions A to D is shown in FIG. The signal control system 1 allocates entry permission (equivalent to a green light signal) to the cars 10 that are scheduled to enter the intersection in units of vehicle groups 20. That is, for each vehicle group 20, the permitted direction that the vehicle group 20 is allowed to enter, i.e., the permitted permitted entry direction, and the period during which entry is permitted, i.e., the permitted entry period, are set. In addition, the permitted entry periods of each vehicle group 20 are set on the same time axis in a manner that does not overlap with each other. Moreover, during the period other than the permitted entry period, all permitted entry directions are treated as stop signals and are processed, thereby managing the signals at the intersection.

[0057] "Car group 20" refers to a group of one or more cars 10 that are scheduled to enter the intersection from the same permitted entry direction. "Scheduled entry into the intersection" means that the direction of travel of the car group 20 is the entry direction into the intersection, and the distance from the car group 20 to the intersection is within the specified distance. Figure 2 In the example, the distance considered as the scheduled intersection is presented as a dotted circular target range with the intersection as the center. Furthermore, the vehicle group 20 whose frontmost vehicle is located within the target range is determined as the "scheduled intersection". Figure 2 In the example, there are vehicle groups 20a to 20d scheduled to enter from four permitted directions A to D, respectively.

[0058] Figure 3 to Figure 7 1 is a diagram for explaining the setting of entry permission for entering an intersection by the signal control system 1. Figure 3 As shown, the signal control system 1 first determines the vehicle group 20 scheduled to enter the intersection for each permitted entry direction of the intersection based on the driving information 32 received from each vehicle 10. Figure 3 In the example, there are vehicle groups 20a to 20d scheduled to enter from four permitted directions A to D, respectively.

[0059] Then, if Figure 4 As shown, for each vehicle group 20, the scheduled arrival time at the intersection is calculated based on the distance to the intersection. The "distance" to the intersection can be set, for example, as the distance from the frontmost position of the frontmost car of the vehicle group 20 to a specified position of the intersection (for example, the position of the stop line). Then, the required time required to reach the intersection is calculated based on the distance to the intersection and the driving speed of the vehicle group, and the time after the required time has passed from the reference time corresponding to the calculation time is set as the scheduled arrival time at the intersection. The driving speed of the vehicle group 20 can be set, for example, as the speed included in the driving information 32. Since the car 10 is automatically driven, it can also be set to a predetermined speed.

[0060] In addition, the signal control system 1 obtains an ideal passing period of the intersection for each vehicle group 20 based on the vehicle group length. The "vehicle group length" can be obtained by adding the distance from the frontmost position of the frontmost car involved in the vehicle group 20 to the rearmost position of the rearmost car to a specified margin distance, or it can be determined based on the number of cars constituting the vehicle group 20. That is, the ideal passing period is set to a period of time corresponding to the vehicle group length starting from the scheduled arrival time of the vehicle group 20 at the intersection. In addition, it is desirable to set the ideal passing period to a specified minimum time period or a period longer than the specified minimum time period for the car 10 to safely enter and pass through the intersection.

[0061] The signal control system 1 sets the allowed entry period of the intersection based on the ideal passing period for each vehicle group 20. At this time, the allowed entry period is set so that the allowed entry periods of each vehicle group 20 do not overlap and are allocated in order of the scheduled arrival time at the intersection from the earliest to the latest.

[0062] Specifically, if Figure 5 As shown, when the ideal passage periods of the vehicle groups 20 do not overlap with each other, the signal control system 1 sets the ideal passage period as the entry permission period. Figure 5 This is an example of a situation where the ideal passing periods of each vehicle group do not overlap. Figure 5 In the example, two vehicle groups 20e and 20f are scheduled to enter the intersection, and their respective ideal passage periods Ie and If do not overlap. Therefore, the ideal passage periods Ie and If of the vehicle groups 20e and 20f are set to the permitted entry periods Te and Tf starting directly from the scheduled arrival times te and tf. In addition, the periods other than the permitted entry periods are set to the periods (permitted entry periods) in which entry is not permitted (stop signal) in all permitted entry directions.

[0063] On the other hand, when the ideal passing periods of the vehicle groups 20 overlap, Figure 6 As shown, the signal control system 1 sets the allowed entry period of the same length as the ideal passing period in order of the scheduled arrival time at the intersection from earliest to latest. Figure 6 This is an example of a situation where the ideal passing periods of each vehicle group 20 overlap. Figure 6In the example, two vehicle groups 20g and 20h are scheduled to enter the intersection, and their respective ideal passing periods Ig and Ih overlap. Therefore, first, the ideal passing period Ig of the vehicle group 20g, which is the earlier of the scheduled arrival times tg and th, is set to the allowed entry period Tg starting directly from the scheduled arrival time tg. Then, a non-allowed entry period is set in which all permitted entry directions are set to stop signals, and an allowed entry period Th is set to be the same length as the ideal passing period Ih of the vehicle group 20h, which is the later of the scheduled arrival times tg and th.

[0064] In addition, when the ideal passing periods of the vehicle groups 20 overlap and the overlapping time of the ideal passing periods is "long" to a certain extent, as shown in FIG. Figure 7 As shown, the signal control system 1 divides the ideal passage period and sets the entry permission period based on the divided periods. Figure 7 This is an example of a case where the ideal passing periods of each vehicle group 20 overlap and the ideal passing periods are divided. When the ideal passing period of the vehicle group 20 is divided, the division is performed in such a manner that the duration of the divided period (divided period) is the prescribed minimum duration or is longer than the prescribed minimum duration. That is, it can be said that the ideal passing period can be divided in the case of a duration that is twice the minimum duration or a duration that is twice the minimum duration (dividable duration). The minimum duration can be set, for example, as a duration that allows the car 10 to safely enter and pass through the intersection. Moreover, the allowed entry period based on the ideal passing period of each vehicle group 20 or the period obtained by dividing the ideal passing period (divided period) is set in a manner that it circulates in order from early to late according to the scheduled arrival time at the intersection.

[0065] When the ideal passing period of a certain vehicle group 20 becomes long, other vehicle groups 20 with overlapping ideal passing periods cannot enter the intersection for a long time, which causes a sense of unfairness. The division of the ideal passing period is performed to alleviate this sense of unfairness. However, when the ideal passing period is divided, the corresponding vehicle group 20 is cut off halfway to pass the intersection. Therefore, in order to avoid the vehicle group 20 being cut off more than necessary, the division period is set to a specified minimum time length or longer than the specified minimum time length.

[0066] exist Figure 7In the example, two vehicle groups 20m and 20n are scheduled to enter the intersection, and their respective ideal passing periods overlap. In addition, the respective ideal passing periods Im and In of the vehicle groups 20m and 20n are both divisible time lengths or are longer than the divisible time lengths and can be divided. Therefore, the respective ideal passing periods Im and In of the vehicle groups 20m and 20n are divided into two periods. Then, the scheduled arrival times tm and tn of the vehicle groups 20m and 20n are from early to late in this order, so the allowed entry period is set in the order of the allowed entry period Tm1 based on the first divided period Im1 of the vehicle group 20m, the allowed entry period Tn1 based on the first divided period In1 of the vehicle group 20n, the allowed entry period Tm2 based on the second divided period Im2 of the vehicle group 20m, and the allowed entry period Tn2 based on the second divided period In2 of the vehicle group 20n. The non-allowed entry period is set outside the allowed entry period.

[0067] In addition, Figure 7 In the example of , the allowed entry period is set to be the same length as the period (divided period) obtained by dividing the ideal passing period, but the allowed entry period may be set to be longer than the divided period. By dividing the ideal passing period, the vehicle group passes the intersection in a divided manner, so it is considered that the second half of the car 10 of the vehicle group stops in front of the intersection.

[0068] The position and speed of the car 10 change all the time, so the signal control system 1 repeats the determination of the vehicle group 20 and the setting of the allowed entry period at a predetermined period. It is also possible to set (reset) the allowed entry period for all vehicle groups 20 scheduled to enter the intersection each time. However, from the perspective of the car 10 being an automatic driving car, the driving speed being stably controlled, and safety, the allowed entry period of the set vehicle group 20 may not be reset (updated) in principle, and the allowed entry period may be additionally set for the vehicle group 20 determined to be newly scheduled to enter the intersection. At this time, the allowed entry period is reset as needed for the vehicle group 20 that overlaps with the ideal passing period of the new vehicle group 20.

[0069] Figure 8 to Figure 10 2 is a diagram for explaining the setting of the entry permission period of a vehicle group 20 that is newly scheduled to enter the intersection. Figure 8 In, with Figure 3 Similarly, the example of an intersection with four permitted entry directions A to D is shown. In the previous setting (reference time t0), the scheduled entry periods for the vehicle groups 20p to 20s that are scheduled to enter the intersection from the permitted entry directions A to D are set. Then, in the current setting (reference time t1), the vehicle group 20t is newly scheduled to enter the intersection from the permitted entry direction A, and the permitted entry period is set for the vehicle group 20t.

[0070] First, if Fig. 9 As shown, the expected arrival time is calculated for the new vehicle group 20t according to the distance to the intersection. In addition, the ideal passing period of the intersection is calculated according to the vehicle group length. Then, based on the ideal passing period, the allowed entry period of the new vehicle group 20t is set in a manner that does not overlap with the allowed entry periods of the other vehicle groups 20p to 20s that have been set.

[0071] That is, when the ideal passage period of the new vehicle group 20t does not overlap with any of the set entry permission periods of the other vehicle groups 20p to 20s, the ideal passage period of the vehicle group 20t is directly set as the entry permission period.

[0072] On the other hand, when the ideal passage period of the new vehicle group 20t overlaps with any of the allowed entry periods of the other vehicle groups 20, the divisible ideal passage periods of the new vehicle group 20t and the overlapping other vehicle groups 20 are divided to set (reset) the allowed entry periods of these vehicle groups 20. Then, the allowed entry periods based on the ideal passage periods of the vehicle groups 20 or the periods obtained by dividing the ideal passage periods are set (reset) in a manner of circulating in the order of the scheduled arrival time at the intersection from the earliest to the latest.

[0073] exist Fig. 9 In the example, the ideal passing period of the new vehicle group 20t overlaps with the allowed entry periods of the other vehicle groups 20r and 20s that have been set. Fig.10 As shown, the ideal passage period Ir of the vehicle group 20r is less than the divisible time length and cannot be divided. On the other hand, the ideal passage period Is of the vehicle group 20s is the divisible time length or longer than the divisible time length and is divided into two periods Is1 and Is2. The ideal passage period It of the vehicle group 20t is also the divisible time length or longer than the divisible time length and is divided into two periods It1 and It2.

[0074] The scheduled arrival time at the intersection is scheduled from early to late in the order of the vehicle groups 20r, 20s, and 20t. Therefore, the allowed entry period is set in the order of the allowed entry period Tr based on the ideal passing period Ir of the vehicle group 20r, the allowed entry period Ts1 based on the first divided period Is1 of the vehicle group 20s, the allowed entry period Tt1 based on the first divided period It1 of the vehicle group 20t, the allowed entry period Ts2 based on the second divided period Is2 of the vehicle group 20s, and the allowed entry period Tt2 based on the second divided period It2 of the vehicle group 20t. Fig.10 Although not shown in the figure, a non-entry period is set in addition to the entry-permitted period.

[0075] [Functional structure]

[0076] Fig.11 1 is a diagram showing an example of a functional configuration of a signal control system 1. Fig.11 The signal control system 1 includes an operation unit 102, a display unit 104, a sound output unit 106, a communication unit 108, a processing unit 200, and a storage unit 300 as functional units, and is configured as a computer system.

[0077] The operation unit 102 is implemented by an input device such as a button switch, a touch panel, or a keyboard, and outputs an operation signal corresponding to the operation performed to the processing unit 200. The display unit 104 is implemented by a display device such as an LCD (Liquid Crystal Display) or a touch panel, and performs various displays corresponding to the display signal from the processing unit 200. The sound output unit 106 is implemented by a speaker, and outputs sound based on a sound signal such as a notification sound input from the processing unit 200. The communication unit 108 is implemented by a wired or wireless communication device, and communicates with an external device such as a communication control device 12 mounted on the vehicle 10 via a wireless base station 3 connected to the communication network N.

[0078] The processing unit 200 is implemented by a computing device such as a CPU (Central Processing Unit), and performs instructions and data transmission to each unit constituting the signal control system 1 based on the program and data stored in the storage unit 300, and performs overall control of the signal control system 1. In addition, the processing unit 200 includes a driving information acquisition unit 202, a determination unit 204, a signal management unit 206, and a notification control unit 208 as functional units involved in this embodiment. However, these functional units can also be configured as independent computing circuits by ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), etc.

[0079] The driving information acquisition unit 202 acquires driving information from the automobile 10. Specifically, the driving information is received from the automobile 10 by communication via the communication unit 108, thereby acquiring the driving information. The driving information acquisition unit 202 updates the automobile management information 310 of the corresponding automobile 10 based on the acquired driving information 32. The automobile management information 310 is information related to the automobile 10 that is controlled by the signal control system 1 and travels on the road network. For each automobile 10, the driving position, driving speed, driving direction, etc. obtained based on the driving information 32 are stored in a manner corresponding to the automobile ID of the automobile 10.

[0080] The determination unit 204 determines the vehicle group 20 consisting of one or more vehicles 10 scheduled to enter the intersection from the same permitted entry direction based on the travel information 32, and determines the scheduled arrival time of the vehicle group 20 at the intersection. In addition, based on the travel information 32, the ideal passing period of the intersection starting from the scheduled arrival time is determined for each vehicle group 20.

[0081] Specifically, referring to the automobile management information 310, a set of automobiles that have the same permitted entry direction into the intersection and whose front and rear automobiles are separated by a prescribed distance or shorter than the prescribed distance is determined as a vehicle group 20. Then, for the determined vehicle group 20, for example, the distance from the frontmost position of the frontmost automobile of the vehicle group 20 to the prescribed position of the intersection (for example, the position of the stop line) is calculated, and the required time required to reach the intersection is calculated based on the distance and the driving speed of the vehicle group 20. Then, the time after the required time has passed from the reference time corresponding to the calculation timing is set as the scheduled arrival time of the intersection. The driving speed of the vehicle group can be set, for example, as the speed included in the driving information 32. Since the car 10 is an automatic driving, it can also be set as a predetermined speed.

[0082] In addition, for example, the distance from the frontmost position of the front car of the vehicle group 20 to the rearmost position of the rearmost car is added to a predetermined margin distance, or a distance predetermined in advance according to the number of cars constituting the vehicle group 20 is used to obtain the vehicle group length. Then, a period of time corresponding to the vehicle group length starting from the scheduled arrival time of the vehicle group at the intersection is set as the ideal passing period.

[0083] The data on the vehicle group 20 determined by the determination unit 204 is stored as the scheduled-entry vehicle group data 321 of the intersection management information 320 related to the corresponding intersection. Fig.12 3 is a diagram showing an example of the scheduled entry vehicle group data 321. Fig.12 As shown, the scheduled entry vehicle group data 321 stores vehicle group data of each vehicle group 20 in correspondence with the reference time. The vehicle group data stores the vehicle group ID, a list of vehicles 10 (vehicle IDs) constituting the vehicle group 20, a permitted entry direction into the intersection, a distance to the intersection, a scheduled arrival time at the intersection, a vehicle group length, and an ideal crossing period of the intersection in correspondence with each other.

[0084] The signal management unit 206 sets a unique permitted entry direction and permitted entry period for each vehicle group 20 on a given time axis, and treats all permitted entry directions as stop signals during the period other than the permitted entry period, thereby managing the signal in accordance with the passage of time. In addition, the permitted entry period is set as the permitted entry direction for the vehicle group 20 to enter, so that the permitted entry periods of each vehicle group 20 do not overlap. In addition, the signal management unit 206 assigns the permitted entry period in order from the vehicle group 20 with the earlier scheduled arrival time, thereby setting the permitted entry period on the time axis. In addition, the permitted entry period of each vehicle group 20 is set based on the ideal passing period. In addition, when there are vehicle groups 20 with overlapping ideal passing periods, the signal management unit 206 divides the ideal passing period of one or both overlapping vehicle groups 20, and sets the permitted entry period corresponding to each of the divided ideal passing periods. In this case, the ideal passage period or the allowed entry period after division is set to be the prescribed minimum time length or longer than the prescribed minimum time length (refer to Figures 4 to 7 ).

[0085] Data related to the signal managed by the signal management unit 206 is stored as entry permission setting data 322 of the intersection management information 320 related to the corresponding intersection. Fig.13 3 is a diagram showing an example of the entry permission setting data 322. Fig.13 As shown, the entry permission setting data 322 is saved in a manner corresponding to a reference time, for each period in a continuous period starting from the reference time, corresponding to whether entry into the intersection is allowed (allowed / not allowed), the permitted direction for entry, and the vehicle group allowed to enter (vehicle group ID).

[0086] The notification control unit 208 generates the signal management information 34 based on the management content of the signal management unit 206 and notifies the automobile 10. In addition, the information of the entry permission period set for the vehicle group 20 is included in the signal management information 34 and notified.

[0087] Specifically, the notification control unit 208 refers to the intersection management information 320 corresponding to the intersection for each intersection in the control target, and generates the signal management information 34 including the permitted entry direction and the permitted entry period set for each vehicle group 20 in the vehicle group 20 scheduled to enter the intersection at a predetermined period. Then, the signal management information 34 is sent to the automobile 10 constituting the vehicle group 20 via the communication unit 108 for notification. The vehicle group 20 scheduled to enter the intersection can be determined based on the scheduled entry vehicle group data 321, and the permitted entry direction and the permitted entry period set for the vehicle group 20 can be determined based on the entry permission setting data 322. The intersection management information 320 is generated for each intersection that is controlled by the signal control system 1, and the permitted direction information related to the structure of the permitted direction, the scheduled entry vehicle group data 321, and the entry permission setting data 322 are stored corresponding to the intersection ID of the intersection.

[0088] The storage unit 300 is implemented by a storage device such as a hard disk, ROM (Read Only Memory), RAM (Random Access Memory), etc., and stores programs and data used by the processing unit 200 to integrally control the signal control system 1. In addition, the storage unit 300 is used as a work area of ​​the processing unit 200 to temporarily store calculation results obtained by the processing unit 200 according to various programs, input data input through the operation unit 102 and the communication unit 108, etc. In this embodiment, the signal control program 302, the car management information 310, and the intersection management information 320 are stored in the storage unit 300.

[0089] The signal control program 302 is executed by the processing unit 200 to realize a function of controlling the signal at a predetermined intersection in a road network on which the car performing the automatic driving travels.

[0090] [Processing flow]

[0091] Fig.14 1 is a flowchart for explaining the flow of the signal control process performed by the signal control system 1. The signal control system 1 performs this process in parallel for each intersection to be controlled.

[0092] First, the determination unit 204 determines the vehicle group 20 scheduled to enter the intersection (step S1). Next, it determines whether the entry permission setting is performed for each of the determined vehicle groups 20 scheduled to enter. If the entry permission setting is performed for all vehicle groups 20 (step S3: "No"), the process proceeds to step S19.

[0093] If there is an unset vehicle group 20 for which entry permission is not set (step S3: "Yes"), the determination unit 204 calculates the scheduled arrival time at the intersection and the ideal crossing period at the intersection for each of the unset vehicle groups 20 (step S5). Next, the signal management unit 206 selects the vehicle group 20 with the earliest scheduled arrival time at the intersection among the vehicle groups 20 for which entry permission is not set (step S7).

[0094] Next, it is determined whether the ideal passage period of the target vehicle group overlaps with the entry permission period of other vehicle groups 20. If not (step S9: "No"), the ideal passage period of the target vehicle group is directly set as the entry permission period (step S11). On the other hand, if the ideal passage period of the target vehicle group overlaps with the entry permission period of other vehicle groups 20 (step S9: "Yes"), the divisible period in the ideal passage period of the target vehicle group and the overlapping other vehicle groups 20 is divided (step S13). Then, the entry permission period based on the ideal passage period or the period (divided period) obtained by dividing the ideal passage period is set for each of these vehicle groups 20 in a manner of circling from the earliest to the latest in the order of the scheduled arrival time at the intersection (step S15). After that, it is determined whether entry permission is set for all vehicle groups 20. If there are vehicle groups 20 that have not been set (step S17: "No"), the process returns to step S7.

[0095] If the entry duration is set for all vehicle groups 20 (step S17: Yes), the notification control unit 208 then generates the signal management information 34 including the permitted entry direction and permitted entry period for each vehicle group 20 that is scheduled to enter the intersection, and notifies each automobile 10 constituting the vehicle group 20 (step S19). After that, the process returns to step S1 and the same process is repeated.

[0096] [Effects]

[0097] According to this embodiment, a new method of signal control at an intersection where an autonomously driven car 10 is traveling can be provided. That is, a completely new signal control of an intersection is performed as follows: the signal control system 1 sets a unique permitted entry direction and permitted entry period for each vehicle group 20 that is scheduled to enter the intersection from the same permitted entry direction on a given time axis, and treats all permitted entry directions as stop signals during periods other than the permitted entry period. In addition, the permitted entry period of each vehicle group 20 is set so that it does not overlap, so that the so-called occupied entry signal control of the intersection is performed in units of the vehicle group 20.

[0098] Since the permitted direction for entering the intersection is limited to one permitted direction at most and the automobiles 10 enter the intersection in units of vehicle groups 20, it is possible to avoid the vehicles 10 from crossing each other at the intersection, and to suppress congestion and realize smooth and efficient traffic flow. Furthermore, the signal management information 34 based on the management content of the signal at the intersection is notified to each automobile 10, so the autonomously driven automobile 10 can enter the intersection according to the permitted entry direction and permitted entry period that are set.

[0099] In addition, it is a matter of course that the applicable embodiments of the present invention are not limited to the above-mentioned embodiments, and can be appropriately modified within the scope not departing from the gist of the present invention.

[0100] Description of Reference Numerals

[0101] 1: signal control system; 200: processing unit; 202: driving information acquisition unit; 204: determination unit; 206: signal management unit; 208: notification control unit; 300: storage unit; 302: signal control program; 310: vehicle management information; 320: intersection management information; 3: wireless base station; 10: vehicle; 12: wireless device; 14: driving control device; 20: vehicle group; 32: driving information; 34: signal management information.

Claims

1. A signal control system for controlling the signal at a predetermined intersection where an autonomous vehicle is traveling. The vehicle comprises: a communication control device that communicates with the signal control system; and an entry control device that performs entry control into the intersection based on given signal management information received from the signal control system. The signal control system comprises: a driving information acquisition unit, which acquires driving information from the vehicle; a determination unit that determines, based on the travel information, a vehicle group consisting of one or more vehicles scheduled to enter the intersection from the same permitted entry direction, and determines a scheduled arrival time of the vehicle group at the intersection; a signal management unit that sets a unique permitted entry direction and permitted entry period for each vehicle group to enter the intersection on a given time axis based on the determination result of the determination unit, and treats all permitted entry directions as stop signals during a period other than the permitted entry period, thereby managing the signal in accordance with the passage of time; as well as A notification control unit generates the signal management information based on the management content of the signal management unit and performs control to notify the vehicle.

2. The signal control system according to claim 1, wherein: The signal management unit sets the permitted entry period by using the permitted entry direction of the vehicle group as the permitted permitted entry direction so that the permitted entry periods of the vehicle groups do not overlap. The notification control unit includes information on the entry permission period set for the vehicle group in the signal management information and notifies the vehicle group.

3. The signal control system according to claim 1 or 2, wherein: The signal management unit assigns the allowed entry period in order from the vehicle group having the earlier scheduled arrival time, thereby setting the allowed entry period on the time axis.

4. The signal control system according to claim 1 or 2, wherein: The determination unit determines, for each of the vehicle groups, an ideal passage period of the intersection starting from the scheduled arrival time based on the travel information, The signal management unit sets the entry permission period for each of the vehicle groups based on the ideal passage period.

5. The signal control system according to claim 4, wherein: When there are the vehicle groups whose ideal passage periods overlap, the signal management unit divides the ideal passage periods of one or both overlapping vehicle groups and sets the entry permission periods corresponding to the divided ideal passage periods.

6. The signal control system according to claim 5, wherein: The signal management unit makes the ideal passage period or the allowed entry period after division to be a predetermined minimum time length or longer than the predetermined minimum time length.

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