Traffic signal information system

Abstract

To provide technology to achieve higher safety for vehicles with automatic driving or driving support functions in a system that provides information on signal indications pertaining to intersections.SOLUTION: A signal information provision system 1 sets limit points, which indicate a permissible limit position of the travel of a vehicle 30 passing through an intersection, for each direction of entry into the intersection based on signal change point information, and transmits signal information pertaining to the intersection, including the signal change point information and the limit point information, to the vehicle 30 traveling in a predetermined range that includes the intersection. The limit points include absolute limit points where driving beyond the limit points is controlled by the driving control function of automatic driving or driving support of the vehicle 30 to deter driving beyond the limit points, and temporary limit points where driving beyond the limit points is determined based on the signal information at an adjacent intersection.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a traffic light information providing system that transmits traffic light information related to intersections to automobiles. [Background technology]

[0002] Traffic signal control is carried out to ensure smooth traffic flow at intersections. Traffic signal control methods are mainly classified into centralized control methods (remote control methods), in which a central device at a traffic control center controls the operation of traffic signals at each intersection, and point control methods, in which each traffic signal operates independently.

[0003] In recent years, technological development of autonomous vehicles capable of autonomous driving has been progressing. In order to pass through intersections safely, autonomous vehicles need to reliably recognize the signal aspects (the color of the traffic light indicators) at the intersections. The mainstream method for autonomous vehicles to recognize information about the signal aspects at intersections is to directly recognize the image of the color of the traffic light indicators using cameras or sensors mounted on the vehicle. On the other hand, methods of acquiring information from external systems (transport infrastructure) and using it for autonomous driving are also being considered (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-27416 Summary of the Invention [Problem to be solved by the invention]

[0005] One possible approach is to combine the use of a method in which an autonomous vehicle directly recognizes the color of traffic light signals using cameras or sensors with a method in which the autonomous vehicle obtains intersection signal phase information from an external system (transport infrastructure). In this case, it would be beneficial for the latter method if the external system (transport infrastructure) were not simply a mechanism for providing intersection signal phase information, but also a mechanism more beneficial to the autonomous vehicle that employs the former method. For example, it would be convenient and desirable to achieve a higher level of autonomous driving safety by achieving fail-safety that cannot be achieved by direct image recognition of traffic light signals alone. These challenges apply not only to fully autonomous vehicles but also to vehicles with driver assistance levels of automation. Furthermore, when realizing regional and urban concepts in which physical traffic lights are eliminated and only fully autonomous vehicles via wireless communication are allowed to operate, it may be necessary to achieve high fail-safety using the latter method alone.

[0006] The problem that the present invention aims to solve is to provide technology that achieves higher safety for vehicles with autonomous driving or driving assistance functions in a system that provides information on traffic light indications at intersections. [Means for solving the problem]

[0007] The first invention to solve the above problem is: A traffic light information providing system that manages traffic light change point information of an intersection and transmits traffic light information related to the intersection to automobiles traveling within a predetermined range including the intersection, The automobile has a driving control function (for example, the function of the driving control device 32 in FIG. 1 ) based on the traffic light information as an automatic driving or driving assistance function, limit point setting means (for example, the limit point setting unit 202 in FIG. 11 ) for setting limit points indicating allowable travel limit positions of the vehicle when passing through the intersection, for each approach direction to the intersection, based on the signal change point information; a transmission control means (for example, the transmission control unit 204 in FIG. 11) for controlling transmission of the signal information including the signal change point information and the limit point information; The traffic signal information system is provided with the above.

[0008] According to the first aspect of the present invention, a technology for realizing higher safety for vehicles equipped with automated driving or driving assistance functions that provides signal information related to intersections can be provided. Specifically, the signal information provision system transmits signal information including signal change point information for an intersection and information on limit points, which are allowable travel limits set for each direction of entry into the intersection based on the signal change point information. A vehicle that receives the signal information can determine whether it can enter the intersection based on the signal change point information and control its own vehicle so that it does not exceed the limit points set for its own direction of entry into the intersection. For example, if a vehicle achieves basic automated driving or driving assistance using a method that directly recognizes the color of traffic lights using images, it can avoid entering an intersection from a direction indicated by a signal phase that prohibits entry, even in situations where it is difficult to distinguish the color of the signal lights due to sunlight or weather conditions, by using the signal information. Of course, even vehicles that do not use a method that directly recognizes the color of traffic lights using images can avoid entering an intersection from a direction indicated by a signal phase that prohibits entry by using the signal information. In addition, for safety reasons, vehicles are controlled so that they do not exceed the limit set for each direction of approach to the intersection. This allows for a high level of fail-safety. Furthermore, traffic signal information can be broadcast simultaneously within a specified range without specifying vehicles.

[0009] The second invention is the first invention, The limit points include absolute limit points at which the driving control function performs control to prevent the vehicle from traveling beyond the limit points, and temporary limit points at which it is determined whether or not the vehicle can travel beyond the limit points based on the traffic light information of adjacent intersections, The limit point setting means sets the absolute limit point at a position before the intersection for an approach direction in which entry into the intersection is prohibited based on the signal change point information, and sets the temporary limit point at a point before the intersection for an approach direction in which entry into the intersection is permitted, depending on the exit direction from the intersection. It is a traffic signal information system.

[0010] According to the second invention, for approach directions where entry into an intersection is prohibited, an absolute limit point that prevents travel beyond the limit point is set at a position before the approach to the intersection, and for approach directions where entry into an intersection is permitted, a temporary limit point that determines whether travel beyond the limit point will be prohibited at the approach destination for each direction of exit from the intersection based on signal information from adjacent intersections. This makes it possible to prevent vehicles from entering the intersection from an approach direction where the signal is red and stop them at a position before the approach to the intersection, and to allow vehicles to enter the intersection only from an approach direction where the signal is green, thereby ensuring safety when passing through the intersection.

[0011] The third invention is the second invention, the limit point setting means sets the absolute limit point or the temporary limit point according to the possibility of entering the intersection for each exit direction when the signal change point information indicates the possibility of entering the intersection for each exit direction from the intersection. It is a traffic signal information system.

[0012] According to the third aspect of the present invention, even for an intersection where the signal aspect indicates whether entry is permitted or not depending on the direction of entry, such as a right-turn arrow, appropriate signal information for the intersection can be transmitted. In this case, if the signal aspect indicates that entry is prohibited for a certain direction of entry, an absolute limit point can be set for that direction of entry, and if the signal aspect indicates that entry is permitted, a temporary limit point can be set for that direction of entry.

[0013] A fourth invention is any one of the first to third inventions, the predetermined range includes a plurality of intersections, the limit point setting means sets the limit point for each intersection included in the predetermined range, for each approach direction to the intersection; the transmission control means transmits the signal change point information and the limit point information for all of the intersections included in the predetermined range; It is a traffic signal information system.

[0014] According to the fourth aspect of the present invention, a vehicle can acquire traffic light information for all intersections within a predetermined range, which allows the vehicle to determine in advance whether or not it is possible to pass through not only the next intersection in the vehicle's direction of travel but also future intersections within the predetermined range, and to grasp the limit points.

[0015] A fifth invention is any one of the first to fourth inventions, a range setting means for setting a plurality of the predetermined ranges such that adjacent predetermined ranges partially overlap; Further provided with the transmission control means controls transmission of the signal information for each of the predetermined ranges. It is a traffic signal information system.

[0016] According to the fifth aspect of the present invention, a vehicle can acquire signal information for intersections in each of the adjacent specified ranges in the overlapping areas of the specified ranges, thereby making it possible to continuously acquire signal information for intersections that the vehicle is scheduled to pass through along the planned driving route.

[0017] A sixth aspect of the present invention is any one of the first to fourth aspects of the present invention, an information request receiving means for receiving an information request including location information of the vehicle from the vehicle; a range setting means for setting the predetermined range including the location information included in the information request; Further provided with the transmission control means controls transmission of the traffic light information relating to the intersections within the predetermined range set by the range setting means to the vehicle that has made the information request; It is a traffic signal information system.

[0018] According to the sixth aspect of the present invention, in response to a request from a vehicle, traffic light information relating to intersections within a predetermined range set to include the location of the vehicle can be transmitted to the vehicle. That is, traffic light information relating to intersections suited to each vehicle can be provided to the vehicle. It is preferable to set the predetermined range so that the location of the vehicle is at the center. [Brief explanation of the drawings]

[0019] [Figure 1] An example of the application of a traffic signal information system. [Figure 2] 10 is an example of signal change point information based on signal cycle information. [Figure 3] Example of control unit area settings. [Figure 4] An example of setting the absolute limit point. [Figure 5] An example of setting a temporary limit point. [Figure 6] An example of setting a temporary limit point near the boundary of a control unit area. [Figure 7] An example of vehicle driving control based on traffic signal information. [Figure 8] An example of vehicle driving control based on traffic signal information. [Figure 9] An example of vehicle driving control beyond the temporary limit. [Figure 10] An example of vehicle driving control in an overlapping area of ​​control unit areas. [Figure 11] An example of the functional configuration of a traffic signal information system. [Figure 12] A variation of the limit point setting. [Figure 13] A variation of the limit point setting. [Figure 14] 10 shows a modified example of the setting of the control unit area. [Figure 15] An example of setting limit points for railroad crossings. [Figure 16] An example of setting limit points for railroad crossings. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the forms to which the present invention can be applied are not limited to the following embodiments. In addition, in the description of the drawings, the same elements are given the same reference numerals.

[0021] [System Configuration] 1 is a diagram showing an application example of a traffic light information providing system 1 according to this embodiment. The traffic light information providing system 1 is a system that manages traffic light change point information at intersections and transmits traffic light information related to the intersections to automobiles 30 traveling within a predetermined area that includes the intersections. Specifically, limit points that indicate the limit of allowable travel positions for automobiles when passing through an intersection are set for each direction of approach to the intersection based on the traffic light change point information, and the transmission of traffic light information including the traffic light change point information and limit point information is controlled.

[0022] The signal change point information, which will be described in detail later, is information based on intersection control information obtained from an external system, traffic signal system 3, and is information on the display times of each indicator at the intersection (the times when the red and green lights of the traffic lights are turned on).

[0023] The traffic signal system 3 is a well-known system that controls traffic (traffic flow) at intersections by controlling the signal aspects of traffic lights, and centrally controls (remotely controls) the operation of traffic lights at multiple intersections. Specifically, it generates signal control commands for the traffic lights at each intersection at a predetermined control period and transmits them to each traffic light. The traffic signal information providing system 1 obtains information including the signal control commands for each intersection from the traffic signal system 3 as intersection control information.

[0024] The automobile 30 is equipped with a driving control device 32 that has a wireless function for receiving traffic signal information transmitted via the wireless base station 10 and a driving control function based on the received traffic signal information as an automatic driving or driving assistance function. The driving control function of the driving control device 32 is described as including a known function for realizing driving control such as collision prevention and maintaining a safe distance between vehicles by image recognition of other traveling vehicles based on images captured by an onboard camera, etc. The driving control function may also include a function for directly recognizing the color of traffic light indicators using an onboard camera, etc., as in the past. In addition, in this embodiment, a planned driving route is set in advance for the automobile 30, and the driving control device 32 controls the driving of the automobile (the automobile 30) along this planned driving route.

[0025] The traffic signal information providing system 1 transmits traffic signal information related to intersections within each control unit area 20, which is a predetermined range, to automobiles 30 traveling within the control unit area 20 via a wireless base station 10 installed in each control unit area 20 so that the communication range of the control unit area 20 includes the entire control unit area 20. The traffic signal information providing system 1 also repeatedly generates and transmits traffic signal information at predetermined intervals. This transmission can be performed in the form of a so-called broadcast, without specifying the destination.

[0026] The traffic light information includes information for each intersection. Each piece of information includes information on the limit points set at the intersection and information on signal change points, associated with the identification information (intersection ID) of the relevant intersection. Limit points are divided into absolute limit points and temporary limit points, which will be described in detail later. The limit point information includes, for each direction of approach to the intersection, information on the location of the absolute limit points and whether they are set (set / cancelled), and the location of the temporary limit points and whether they are set (set / cancelled).

[0027] Signal change point information is information based on intersection control information obtained from the traffic signal system 3. FIG. 2 is a diagram illustrating signal change point information. FIG. 2 shows an example of signal change point information for a cross intersection. Signal change point information is obtained based on signal cycle information, which is information related to the signal cycle of the intersection. Signal cycle information includes a phase stage table and signal control parameters such as cycle length, split, and offset. The signal control parameters are controlled by signal control commands from the traffic signal system 3, which are included in the intersection control information. Signal change point information is information that determines the transition times (change times) of each aspect (red and green light colors) for each approach direction to the intersection during the period from the current time t0 until a predetermined number of cycles have elapsed. Using the signal change point information, it is possible to grasp the transition times (change times) of each aspect in the near future as absolute times.

[0028] FIG. 3 is a diagram illustrating the setting of the control unit area 20. In FIG. 3, solid lines on the top, bottom, left, and right indicate roads, and intersections where the solid lines intersect are indicated as intersections by four dots representing traffic lights. Each circular area indicated by a dashed line indicates a control unit area 20. As shown in FIG. 3, a plurality of control unit areas 20 are set, and adjacent areas 20 are set so that they partially overlap. When a vehicle 30 is located in an overlapping portion of control unit areas 20, it can acquire traffic light information for each of the overlapping control unit areas 20. Therefore, unless a malfunction or other problem occurs, a vehicle 30 traveling on a road can continuously acquire traffic light information for each adjacent intersection.

[0029] 4 and 5 are diagrams illustrating the setting of limit points at an intersection. FIGS. 4 and 5 show an example of a cross intersection with four routes A to D. Limit points are set for each approach direction to the intersection according to the current aspect based on the signal change point information for the intersection. In other words, in the example of FIGS. 4 and 5, limit points are set for each approach direction A to D from each of the four routes A to D. However, for ease of explanation, the example illustrates the setting of the limit point for approach direction A. Limit points include absolute limit points, which are controlled by a cruise control function of a cruise control device 32 mounted on a vehicle 30 to prevent the vehicle from traveling beyond the limit point, and temporary limit points, which are determined based on the signal information of adjacent intersections to allow or disallow travel beyond the limit point.

[0030] Figure 4 shows a case where the current traffic light for approach direction A based on the traffic light change point information is "red (may include yellow)." In this case, it is not possible to approach the intersection from approach direction A, and an absolute limit point is set at a position before approaching the intersection. The absolute limit point is set, for example, at the position of the stop line just before the intersection.

[0031] FIG. 5 shows a case where the current traffic light for approach direction A based on the traffic light change point information is other than "red (yellow may also be included)." In this case, approach to the intersection is permitted from approach direction A, and a temporary limit point is set at the exit point of the intersection for each exit direction from the intersection. In the example of FIG. 5, a temporary limit point is set for each of the three exit directions B to D (corresponding to turning left, going straight, and turning right at the intersection) for each of the three routes B to D. The temporary limit point is set at a position beyond the intersection. The position of the temporary limit point is fixed to a predetermined position after exiting the intersection, but it may also be variable.

[0032] Furthermore, if the adjacent intersection ahead in the relevant exit direction is outside the control unit area 20 but within another control unit area 20, the temporary limit point is set at a position included in the overlapping portion with the other control unit area 20. FIG. 6 is a diagram for explaining the setting of temporary limit points in overlapping portions of control unit areas 20 (20a, 20b). In the example shown in FIG. 6, intersection b ahead in the exit direction a from intersection a within the control unit area 20a is outside the control unit area 20a but within another adjacent control unit area 20b. Therefore, the temporary limit point a for the exit direction a is set at a position included in the overlapping portion with the control unit area 20b. By setting the temporary limit point in this manner, it becomes possible for the vehicle 30 to travel beyond the temporary limit point, as will be described in detail below.

[0033] [Automobile driving control] 7 and 8 are diagrams illustrating the driving control of the automobile 30 based on traffic light information. The driving control device 32 mounted on the automobile 30 controls the driving of the automobile (the automobile 30) by taking into consideration not only traffic light information but also various factors such as the planned driving route of the automobile and the surrounding conditions including the presence of other automobiles and pedestrians that can be grasped by image recognition of images captured by the on-board camera, but here, the description will focus on the driving control based on traffic light information.

[0034] 7 shows a case where an absolute limit point is set in the direction of entry of automobile 30. In this case, automobile 30 is controlled by cruise control device 32 so that it stops by the set absolute limit point, i.e., so that it does not go beyond the absolute limit point. If there is another automobile ahead, a conventionally known function for controlling cruise while maintaining a safe distance is activated, and automatic braking control, etc., is performed. Therefore, if there is another automobile between the own vehicle and the absolute limit point, the own vehicle is controlled to stop in front of the other automobile to avoid a collision. Therefore, the absolute limit point is set from the perspective of safety so that the own vehicle never goes beyond this position.

[0035] FIG. 8 illustrates a case where an absolute limit point is not set (is released) for the approaching direction of the automobile 30, but a temporary limit point is set for the exiting direction. As an example, the automobile 30 turns right at an intersection. In this case, the cruise control device 32 controls the automobile 30 to stop before the temporary limit point, i.e., not to go beyond the temporary limit point. Specifically, the cruise control device 32 of the automobile 30 determines whether the automobile 30 can pass through the intersection based on the current position of the automobile, signal change point information, and the like. That is, the cruise control device 32 determines, from the signal change point information, the time until the traffic light for the approaching direction changes to red (or yellow) (corresponding to the time until the absolute limit point for the approaching direction is set), and determines whether the automobile 30 can pass through the intersection before that time elapses based on the traveling speed of the automobile 30, the distance to the intersection, and other factors (such as the presence of other automobiles). If it is determined that the automobile 30 can pass through the intersection, the cruise control device 32 controls the automobile 30 to pass through the intersection and stop before the temporary limit point set for the exiting direction. In the example of Fig. 8, the automobile 30 enters the intersection from route A, turns right, and exits onto route D, so the vehicle is controlled to stop by the temporary limit point in the exit direction from route A to route D. On the other hand, if it is determined that the intersection is impassable, the cruise control device 32 controls the vehicle to stop by the absolute limit point in the entry direction.

[0036] The traffic light information is transmitted repeatedly at a predetermined interval. Therefore, even if the vehicle 30 stops at the absolute limit point set before entering the intersection, the absolute limit point setting is canceled after a certain period of time and a temporary limit point is set, allowing the vehicle 30 to enter the intersection.

[0037] Incidentally, since the traffic light information includes information related to each intersection within the control unit area 20, the automobile 30 acquires traffic light information not only for the upcoming intersection but also for intersections ahead of it. Therefore, based on the traffic light information for the upcoming intersection, the automobile 30 can travel beyond the temporary limit point to the limit point set at the upcoming intersection.

[0038] FIG. 9 is a diagram illustrating traveling beyond a temporary limit point. In FIG. 9, the automobile 30 is scheduled to turn right at the upcoming intersection c in the exit direction c. Therefore, traveling control is basically performed to prevent traveling beyond the temporary limit point c set in the exit direction c. However, the temporary limit point is a limit point at which permission or prohibition of traveling beyond the limit point is determined based on signal information from adjacent intersections. Therefore, if the traveling control device 32 obtains signal information from intersection d, which is an intersection adjacent to intersection c in the exit direction c, it can cause the host vehicle (automobile 30) to travel beyond the temporary limit point c. Because intersections c and d are intersections within the same control unit area 20, the traveling control device 32 can obtain signal information from intersections c and d. Therefore, since the signal information for intersection d has already been obtained, the traveling control device 32 can cause the host vehicle (automobile 30) to travel beyond the temporary limit point c to the limit point set for intersection d based on this signal information. In other words, the automobile 30 is not prevented from traveling beyond the temporary limit point c, but is allowed to travel up to the limit point related to the intersection d. For example, if an absolute limit point is set for the approach direction to the intersection d, the automobile 30 is controlled to stop before reaching the absolute limit point.

[0039] On the other hand, if an absolute limit point has not been set (is released) at intersection d and a temporary limit point for the exit direction has been set, the cruise control device 32 determines whether intersection d is passable (i.e., whether the traffic light for the entrance direction to intersection d is green or not) based on the traffic light change point information of intersection d. Then, depending on whether intersection d is passable or not, the cruise control device 32 controls the cruise of the vehicle (automobile 30) so that the vehicle stops by the limit point of intersection d. In other words, if it is determined that intersection d is not passable, the cruise control device 32 controls the vehicle to stop by the absolute limit point for the entrance direction of intersection d. If it is determined that intersection d is passable, the cruise control device 32 controls the vehicle to stop by the temporary limit point set for the exit direction of intersection d along the planned travel route. Note that since the traffic light change point information is information for several cycles (information of a finite time length), if the time until reaching the intersection exceeds a certain time, the signal aspect at the time of arrival cannot be determined, and the intersection is therefore determined to be "impassable."

[0040] In this way, based on the signal change point information for intersections beyond the nearest intersection, it is possible to determine whether or not the vehicle 30 can travel beyond the temporary limit point set for the exit direction. Therefore, for intersections that the vehicle 30 plans to pass along the planned travel route within the control unit area 20 in which the vehicle is located, the vehicle 30 determines, in the order in which the intersections are to be passed, whether an absolute limit point has been set for the entry direction, and if no absolute limit point has been set, whether or not the vehicle can travel beyond the temporary limit point set for the exit direction. This allows the vehicle 30 to travel up to the limit point set for an intersection that can be reached within the range of the acquired signal information. In the example of FIG. 9, the vehicle 30 plans to travel through the nearest intersection (intersection c), intersection d, and intersection e in that order, so the vehicle 30 is allowed to travel up to the limit point of the intersection e, which is the third intersection that the vehicle plans to pass.

[0041] As shown in Fig. 6, for an intersection just before the boundary of a control unit area 20, the temporary limit point is set so as to be included in the overlapping portion of an adjacent control unit area 20. Therefore, as shown in Fig. 10, when the automobile 30 reaches (approaches) the temporary limit point e set at the intersection e just before the boundary of a control unit area 20e, the automobile 30 can acquire signal information related to each intersection in the adjacent control unit area 20f. Then, based on the signal information, the stop inhibition at the temporary limit point e is released, and the automobile 30 can travel toward the intersection in the adjacent control unit area 20f.

[0042] In this way, a mechanism for realizing driving control based on signal information including signal change point information and limit point information can realize higher safety for the automobile 30 having an automatic driving or driving assistance function. That is, in addition to the safety of driving control guaranteed by conventionally known functions related to automatic driving or driving assistance, safe driving control based on signal change point information and limit point information can be performed, thereby realizing driving control of the automobile with excellent fail-safety.

[0043] [Function Configuration] Fig. 11 is a diagram showing an example of the functional configuration of the traffic signal information providing system 1. According to Fig. 11, the traffic signal information providing system 1 includes, as functional units, 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, and is configured as a type of computer system.

[0044] The operation unit 102 is realized 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 realized by a display device such as an LCD (Liquid Crystal Display) or a touch panel, and performs various displays according to display signals from the processing unit 200. The sound output unit 106 is realized by a speaker, and outputs sound based on audio signals such as alarm sounds input from the processing unit 200. The communication unit 108 is realized by a wired or wireless communication device, and communicates with external devices such as the traffic signal system 3 via the communication network N1, and also communicates wirelessly with external devices such as the cruise control device 32 installed in the automobile 30 via a wireless base station connected to the communication network N2.

[0045] The processing unit 200 is realized by an arithmetic device such as a CPU (Central Processing Unit), and issues instructions and transfers data to each unit constituting the traffic signal information providing system 1 based on the programs, data, etc. stored in the storage unit 300, thereby performing overall control of the traffic signal information providing system 1. The processing unit 200 also has, as functional units according to this embodiment, a limit point setting unit 202, a transmission control unit 204, a range setting unit 206, and a clock unit 210. However, these functional units can also be configured as independent arithmetic circuits using an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc.

[0046] The limit point setting unit 202 sets limit points, which indicate the limit of allowable travel of the vehicle when passing through an intersection, for each approach direction to the intersection based on the signal change point information. Limit points include absolute limit points, which are controlled by the vehicle's cruise control function to prevent the vehicle from traveling beyond the limit point, and temporary limit points, which determine whether or not the vehicle can travel beyond the limit point based on the signal information of adjacent intersections. Based on the signal change point information, the limit point setting unit 202 sets absolute limit points at positions before approaching the intersection for approaches that prohibit entry into the intersection, and sets temporary limit points at the end of the intersection for approaches that permit entry into the intersection for each exit direction from the intersection (see FIGS. 4 and 5). The predetermined range includes multiple intersections, and the limit point setting unit 202 sets limit points for each approach direction to the intersection for each intersection included in the predetermined range (see FIG. 3).

[0047] Specifically, for each intersection, the limit point setting unit 202 sets an absolute limit point for the approach direction that shows a stop aspect (red (which may include yellow)) in accordance with the current signal aspect (each light color of red or green) based on the signal change point information, and sets a temporary limit point for the approach direction that does not show a stop aspect, thereby repeatedly performing the process of setting limit points for each approach direction at a predetermined cycle. In this embodiment, the positions of the limit points are fixed and are defined as being included in the intersection management information 320.

[0048] The intersection management information 320 is generated for each intersection and stores limit point information that defines the positions of absolute limit points and temporary limit points for each approach direction, associated with an intersection ID that is the identification information of the corresponding intersection, intersection control information obtained from the traffic signal system 3, signal change point information based on this intersection control information (see Figure 2), and transmitted signal information that has been transmitted so far by the transmission control unit 204.

[0049] The transmission control unit 204 controls the transmission of signal information including signal change point information and limit point information (see FIG. 1). The transmission control unit 204 also transmits signal change point information and limit point information for all intersections included in a predetermined range, and controls the transmission of signal information for each predetermined range.

[0050] Specifically, the transmission control unit 204 generates signal information for each intersection including the limit points set by the limit point setting unit 202 (limit points for each entry direction (absolute limit points or temporary limit points)) and current signal change point information (see Figure 2), and for each control unit area 20, which is a predetermined range, transmits the signal information for each intersection within the control unit area 20 to vehicles 30 within the control unit area 20 via the radio base station 10 installed in the control unit area 20 at a predetermined interval.

[0051] The range setting unit 206 sets a plurality of predetermined ranges such that adjacent predetermined ranges partially overlap each other (see FIG. 3). The predetermined ranges can be set, for example, in accordance with the control unit area setting information 310. The control unit area setting information 310 is generated for each control unit area, which is a predetermined range, and stores intersection IDs of intersections within the area and base station IDs of wireless base stations 10 in association with an area ID, which is identification information for the corresponding control unit area.

[0052] The clock unit 210 is configured with a transmission circuit having a crystal oscillator, has a function of synchronizing with Japan Standard Time, and measures the current time and the time elapsed since a specified timing. Japan Standard Time can be acquired from an NTP server, a GNSS (Global Navigation Satellite System), a radio-controlled clock, etc.

[0053] The storage unit 300 is realized by a storage device such as a hard disk, a ROM (Read Only Memory), or a RAM (Random Access Memory), and stores programs, data, and the like used by the processing unit 200 to comprehensively control the traffic signal information provision system 1. The storage unit 300 is also used as a working area for the processing unit 200, and temporarily stores results of calculations executed by the processing unit 200 in accordance with various programs, input data via the operation unit 102 and the communication unit 108, and the like. In this embodiment, the storage unit 300 stores a traffic signal information provision program 302, control unit area setting information 310, and intersection management information 320.

[0054] The signal information providing program 302, when executed by the processing unit 200, realizes the function of managing signal change point information at intersections and transmitting signal information related to the intersections to automobiles traveling within a predetermined range that includes the intersections.

[0055] [Action and effect] According to this embodiment, a system for providing intersection-related signal information to a vehicle 30 with an automated driving or driving assistance function can achieve higher safety for the vehicle 30. Specifically, the traffic light information providing system 1 transmits signal information including signal change point information for the intersection and information on limit points, which are allowable travel limits set for each direction of entry into the intersection based on the signal change point information. After receiving the signal information, the vehicle 30 determines whether it is possible to enter the intersection based on the signal change point information and controls its own vehicle so as not to exceed the limit points set for its own vehicle's direction of entry into the intersection. For example, if the vehicle 30 achieves basic automated driving or driving assistance using a method of directly recognizing the color of traffic light indicators based on images, it can avoid entering an intersection from an entry direction indicated by a signal phase that prohibits entry, even in situations where it is difficult to distinguish the color of the indicator lights due to sunlight or weather conditions, by using the signal information. Of course, even vehicles 30 that do not employ a method of directly recognizing the color of traffic light indicators based on images can avoid entering an intersection from an entry direction indicated by a signal phase that prohibits entry by using the signal information. In addition, for safety reasons, the vehicle 30 is controlled so that it does not exceed the limit set for each direction of approach to the intersection. This allows for a high level of fail-safety. Furthermore, the traffic light information can be broadcast simultaneously to all vehicles within a predetermined range without specifying the vehicle 30.

[0056] [Variations] It should be noted that the embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can of course be modified as appropriate within the scope of the present invention.

[0057] (A) Setting the limit When the signal change point information indicates whether or not it is possible to enter the intersection depending on the direction of exit from the intersection, the signal information providing system 1 may set an absolute limit point or a temporary limit point depending on whether or not it is possible to enter depending on the direction of exit.

[0058] An example of such an intersection is one that uses different signal aspects for going straight, turning left, and turning right, such as a right-turn arrow signal. Figures 12 and 13 show examples of intersections where the signal for approach direction A is red based on signal change point information, but the possibility of entry is indicated for each exit direction. Looking at the diagram connecting routes A and C, the roads on the left and right are main roads with two lanes on each side, while looking at the diagram connecting routes B and D, the roads on the up and down are secondary roads with one lane on each side. Furthermore, of the two lanes of the main road, the left lane when entering the intersection is a straight-through left-turn lane that allows going straight and turning left, and the right lane is a right-turn-only lane. Figure 12 shows a case where a straight-through arrow signal and a left-turn arrow signal are displayed for approach direction A. In this case, temporary limit points are set for the straight-through and left-turn directions of the exit directions relative to approach direction A, and an absolute limit point is set for the right-turn direction. FIG. 13 shows a case where a signal aspect of a right-turn arrow signal is displayed for approach direction A. In this case, among the approach directions relative to approach direction A, a temporary limit point is set for the right-turn direction, and absolute limit points are set for each of the straight-ahead direction and the left-turn direction. The signal information for the intersection includes signal change point information including the signal aspect for each approach direction as described above, and information on limit points for each approach direction. If the host vehicle is automobile 30X traveling in the straight-ahead left-turn lane, the cruise control device 32 performs cruise control based on the limit points corresponding to the straight-ahead direction and the left-turn direction, respectively. If the host vehicle is automobile 30Y traveling in the right-turn-only lane, the cruise control device 32 performs cruise control based on the limit point corresponding to the right-turn direction.

[0059] (B) Setting of control unit areas according to the vehicle Furthermore, the traffic signal information providing system 1 may receive an information request from a vehicle 30 including the position information of the vehicle 30, set a control unit area 20 which is a predetermined range including the position information included in the information request, and perform control to transmit traffic signal information related to intersections in the control unit area 20 which is the set predetermined range to the vehicle 30 that made the information request. In this case, as shown in Fig. 14, for example, when the control unit area 20 is set based on the position information when the vehicle 30 is located at the position of vehicle 30-1, a control unit area 20-1 is set which is approximately centered on the position of vehicle 30-1, and when the control unit area 20 is set based on the position information when the vehicle 30 is located at the position of vehicle 30-2, a control unit area 20-2 is set which is approximately centered on the position of vehicle 30-2.

[0060] (C)Railroad crossing Furthermore, the signal information providing system 1 may transmit information related to the blocking of a railroad crossing instead of an intersection. Specifically, the signal information providing system 1 acquires information related to blocking control, including whether the railroad crossing is currently blocked or not, the scheduled time for the blocking to begin, etc., from the railroad crossing system. Based on the acquired information, the signal information providing system 1 transmits signal information including a limit point set according to whether the railroad crossing is blocked or not, and the information.

[0061] 15 and 16 are diagrams showing examples of setting limit points for a railroad crossing. Fig. 15 shows the case where the railroad crossing is closed. In this case, absolute limit points are set at positions before the crossing for all approach directions to prevent automobile 30 from entering the crossing. Fig. 16 shows the case where the railroad crossing is open. In this case, automobile 30 can enter the crossing, so temporary limit points are set at positions beyond the crossing for all approach directions. [Explanation of symbols]

[0062] 1. Traffic signal information system 200...Processing section 202...Limit point setting section 204...Call control unit 206...Range setting section 210...Clock section 300...Storage section 302...Signal Information Program 310...Control unit area setting information 320...Intersection management information 10...Radio base station 20...Control unit area 30...Automobile 32...Traction control device 3. Traffic signal system

Claims

1. A traffic light information providing system that manages traffic light change point information of an intersection and transmits traffic light information related to the intersection to automobiles traveling within a predetermined range including the intersection, the automobile has a driving control function based on the traffic signal information as an automatic driving or driving assistance function, limit point setting means for setting limit points indicating allowable travel limit positions of the vehicle when passing through the intersection, for each approach direction to the intersection, based on the signal change point information; a transmission control means for controlling transmission of the signal information including the signal change point information and the limit point information; A traffic signal information providing system comprising:

2. The limit points include absolute limit points at which the driving control function performs control to prevent the vehicle from traveling beyond the limit points, and temporary limit points at which it is determined whether or not the vehicle can travel beyond the limit points based on the traffic light information of adjacent intersections, The limit point setting means sets the absolute limit point at a position before the intersection for an approach direction in which entry into the intersection is prohibited based on the signal change point information, and sets the temporary limit point at a point before the intersection for an approach direction in which entry into the intersection is permitted, depending on the exit direction from the intersection. The traffic signal information providing system according to claim 1 .

3. the limit point setting means sets the absolute limit point or the temporary limit point according to the possibility of entering the intersection for each exit direction when the signal change point information indicates the possibility of entering the intersection for each exit direction from the intersection. The traffic signal information providing system according to claim 2 .

4. the predetermined range includes a plurality of intersections, the limit point setting means sets the limit point for each intersection included in the predetermined range, for each approach direction to the intersection; the transmission control means transmits the signal change point information and the limit point information for all of the intersections included in the predetermined range; The traffic signal information providing system according to any one of claims 1 to 3.

5. a range setting means for setting a plurality of the predetermined ranges such that adjacent predetermined ranges partially overlap; Further provided with the transmission control means controls transmission of the signal information for each of the predetermined ranges. The traffic signal information providing system according to any one of claims 1 to 3.

6. an information request receiving means for receiving an information request including location information of the vehicle from the vehicle; a range setting means for setting the predetermined range including the location information included in the information request; Further provided with the transmission control means controls transmission of the traffic light information relating to the intersections within the predetermined range set by the range setting means to the vehicle that has made the information request. The traffic signal information providing system according to any one of claims 1 to 3.

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