Traffic signal controlling device and traffic signal controlling method

Abstract

To provide a traffic signal controlling device and a traffic signal controlling method that performs a switching operation within scheduled seconds even if some abnormality occurs.SOLUTION: A traffic signal controlling device 10 comprises: an information processing device 21 for forming scheduled information regarding switching of a signal aspect; a communication device 50 that provides the scheduled information to an external party; a signal control circuit 25 that controls a display state of a traffic signal lighting device SG based on a command from the information processing device 21; and a storage unit 26 that holds the scheduled information, wherein the signal control circuit 25 controls a display state of the traffic signal lighting device SG in accordance with the scheduled information at a transient timing TMtr when the device switches from a normal operation according to the information processing device 21 to a default degeneration operation.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a traffic signal control device and a traffic signal control method for providing schedule information regarding switching of signal aspects to an external device. [Background technology]

[0002] A traffic signal device is known in which, when a detection means detects an abnormality in a CPU that executes software, a control circuit autonomously controls the traffic signal device that is the object of control (Patent Document 1).

[0003] The method of Patent Document 1 does not take into consideration the case where the estimated number of seconds until the signal aspect changes is provided as the signal information of the traffic light to nearby vehicles, etc. In other words, for example, if an abnormality occurs in the CPU that runs the software, degenerate operation will be performed in the lower control circuit, but because the timing and number of seconds are not synchronized with the software control, control will be performed with a number of seconds different from the estimated number of seconds already provided to nearby vehicles, etc., which may cause problems in the operation of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-032236 A Summary of the Invention

[0005] The present invention has been made in consideration of the above-mentioned background, and aims to provide a traffic signal control device and a traffic signal control method which, when a planned number of seconds until a signal aspect changes is provided, performs a switching operation at the planned number of seconds even if, for example, an abnormality occurs in the CPU executing the software.

[0006] In order to achieve the above-mentioned object, the traffic signal control device of the present invention comprises an information processing device that creates schedule information regarding switching of signal indications, a communication device that provides the schedule information to the outside, a signal control circuit that controls the display state of a traffic signal lamp based on an instruction from the information processing device, and a memory unit that retains the schedule information, and the signal control circuit controls the display state of the traffic signal lamp in accordance with the schedule information at a transitional timing when switching from normal operation according to the information processing device to a default degenerate operation.

[0007] In the above-mentioned traffic signal control device, the signal control circuit controls the display state of the traffic signal lights in accordance with the scheduled information at the transitional timing when it switches from normal operation in accordance with the information processing device to pre-defined degenerate operation. Therefore, even if for some reason control switches from the information processing device to degenerate operation by the signal control circuit, the traffic signal or the multiple traffic signal lights that make it up will operate in accordance with the scheduled information provided externally at the transitional timing, thereby preventing any disruption to the operation of the vehicle that receives the information.

[0008] In order to achieve the above-mentioned object, the traffic signal control method of the present invention is a traffic signal control method in a traffic signal control device which has an information processing device which creates scheduled information regarding switching of signal aspects which is provided externally, and a signal control circuit which controls the display state of traffic signal lights based on commands from the information processing device, and which controls the display state of the traffic signal lights in accordance with the scheduled information provided externally at a transitional timing when switching from normal operation according to the information processing device to a default degenerate operation by the signal control circuit. [Brief description of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram illustrating a road on which a traffic signal control device according to a first embodiment is installed. [Diagram 2] FIG. 2 is a block diagram showing a configuration example of a traffic signal control device. [Diagram 3] (A) shows an example of a traffic signal time table, and (B) shows the estimated number of seconds for one cycle calculated from the time table. [Figure 4]4 is a conceptual flowchart illustrating the operation of the traffic signal control device of the first embodiment. [Diagram 5] 4 is a conceptual flowchart illustrating the operation of the traffic signal control device of the first embodiment. [Figure 6] (A) is a conceptual diagram explaining the switching of operating states, (B) is an example of a time table for a traffic signal light, and (C) is a table showing the estimated number of seconds calculated from the time table. [Figure 7] 10 is a conceptual flowchart illustrating the operation of a traffic signal control device according to a second embodiment. [Figure 8] FIG. 4 is a conceptual diagram illustrating switching of an operating state. [Figure 9] FIG. 11 is a diagram illustrating a traffic signal control device according to a third embodiment. [Figure 10] 10 is a conceptual flowchart illustrating the operation of a traffic signal control device according to a third embodiment. [Figure 11] 10 is a conceptual flowchart illustrating the operation of a traffic signal control device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] A traffic signal control device and a traffic signal control method according to a first embodiment of the present invention will be described below. Fig. 1 is a conceptual diagram illustrating a road RA and an intersection CS to which a traffic signal control device 10 according to the first embodiment is introduced. Fig. 2 is a block diagram illustrating an example of the configuration of a signal system 100 including the traffic signal control device 10 and the like.

[0011] 1, among roads RA, a road on which a vehicle VE of interest is traveling is defined as a main road RA1, and a road intersecting the main road RA1 is defined as a secondary road RA2. At an intersection CS, vehicle lights SG1 and pedestrian lights SG1a for the main road RA1, and vehicle lights SG2 and pedestrian lights SG2a for the secondary road RA2 are provided. The vehicle lights SG1 and SG2 and the pedestrian lights SG1a and SG2a are also referred to as traffic signal lights SG.

[0012] The traffic signal control device 10 controls the operation of multiple traffic signal lights SG (specifically, vehicle lights SG1, SG2 and pedestrian lights SG1a, SG2a) that make up the traffic lights installed at the intersection CS, and supports traffic at the intersection CS by transmitting schedule information that is processed signal information related to the display operation of each traffic signal light SG to the outside. The outside is, for example, a vehicle VE or a communication device 50 described later. In this embodiment, an example is described in which the traffic signal control device 10 provides schedule information, etc. of the traffic signal lights SG to a vehicle VE traveling on a road RA via the communication device 50.

[0013] 2, in the signal system 100, the traffic signal control device 10 includes an information processing device 21 consisting of a microcomputer, a signal control circuit 25, a memory unit 26, a timing unit 27, a light drive unit 13, and a time acquisition unit 14. Here, the signal control circuit 25, the memory unit 26, the timing unit 27, etc. are composed of, for example, an LSI (large scale integrated circuit).

[0014] The information processing device 21 controls the operation of the traffic signal control device 10 in cooperation with the signal control circuit 25 and the communication device 50. The information processing device 21 has a CPU 21a and a storage device 21b. The information processing device 21 creates schedule information related to switching of signal aspects and manages the operation state of the traffic signal control device 10. The storage device 21b of the information processing device 21 stores various programs for operating the information processing device 21. Specifically, the storage device 21b stores a program for controlling the operation of the light unit driving unit 13 via the signal control circuit 25, for example, and stores a program for creating schedule information related to switching of signal aspects and a program for transmitting the schedule information to the communication device 50 at an appropriate timing. The storage device 21b stores signal information for causing the light unit driving unit 13 to perform normal operation and schedule information for external distribution. This signal information includes a time table and current information for all traffic signal lights SG under management.

[0015] FIG. 3(A) illustrates a time table of the traffic signal lights SG among the signal information, and FIG. 3(B) is a table showing the planned number of seconds for one cycle calculated from the time table. In FIG. 3(A), the reference characters 1 and 1P indicate the vehicle light SG1 and the pedestrian light SG1a of the main road RA1, and the reference characters 2 and 2P indicate the vehicle light SG2 and the pedestrian light SG2a of the secondary road RA2. The time table shown in FIG. 3(A) is, for example, a table in which the indication of an intersection CS is divided into a number of steps and the number of seconds for each step is added, and corresponds to a table of the operation cycle of a traffic light. A step is the smallest unit of a signal indication. The planned number of seconds for one cycle shown in FIG. 3(B) is a table summarizing the planned number of seconds for each indication state or light color calculated from the time table for one cycle of indications repeated by the traffic signal lights SG. In addition, the red light of the vehicle lamp SG2 indicated by reference symbol 2 continues from the end to the beginning of the cycle, so the scheduled number of seconds is ultimately 62 seconds in total.

[0016] Of the signal information, the current information includes the current light color of each traffic signal light device SG and the number of seconds it is being executed. The scheduled information specifically includes the current light color or future light color of each traffic signal light device SG and the number of seconds remaining for that light color (also called scheduled display time). The scheduled information may include the current time acquired by the time acquisition unit 14. The scheduled information is not limited to information including the remaining time until the display of the current or future light color ends, but may also include the absolute time or clock time when the display of the current or future light color ends.

[0017] 2, the signal control circuit 25 operates under the control of the information processing device 21 and causes the lamp driving unit 13 to perform a desired display operation. The signal control circuit 25 performs signal processing on a digital signal, and includes a logic circuit and a memory.

[0018] The memory unit 26 is a register and other circuits that hold information necessary for the operation of the signal control circuit 25, and the timer unit 27 is a circuit that measures elapsed time, time width, etc. based on a clock signal from a clock circuit (not shown).

[0019] The signal control circuit 25 basically operates based on commands from the information processing device 21 under the management of the information processing device 21, but can also operate the lamp driving unit 13 independently based on the signal information stored in the storage unit 26. The signal control circuit 25 can switch processing operations between, for example, (1) a normal operation mode in which the lamp driving unit 13 performs a specified operation based on commands from the information processing device 21, (2) a default degenerate operation mode in which a default degenerate operation is performed independently of the information processing device 21, and (3) a preliminary degenerate operation mode in which a preliminary degenerate operation is performed at a transitional timing when the normal operation is switched to the default degenerate operation. Here, the default degenerate operation means an operation of the traffic signal control device 10 that is performed after, for example, the information processing device 21 breaks down and control is switched from the information processing device 21 to the signal control circuit 25.

[0020] The signal information stored in the memory unit 26 is for executing a default degenerate operation for all traffic signal lights SG that are the control targets of the traffic signal control device 10, and includes a time table and current information. The time table and current information are the same as those stored in the memory unit 21b of the information processing device 21, but the time table can be dedicated to the default degenerate operation (specifically, the number of seconds per step is different). The memory unit 26 also has a role of temporarily storing the scheduled information created and provided by the higher-level information processing device 21 or equivalent time table information. The clock unit 27 enables the determination of the retention time of the current display state of the traffic signal lights SG. Specifically, the clock unit 27 measures the number of seconds executed from the start of displaying the current light color, for example, and enables the determination of whether the number of seconds executed has reached the scheduled number of seconds and the remaining time until the number of seconds executed reaches the scheduled number of seconds. The number of seconds executed corresponds to the elapsed time from the start of displaying the current light color. The timer unit 27 may start measuring time in response to a trigger signal, or may record the absolute time or the current time as absolute time while updating it. As will be described in detail later, the timer unit 27 receives a synchronization signal from the information processing device 21 before the transitional timing and corrects either the elapsed time or the absolute time. This causes the signal control circuit 25 to perform an operation corresponding to the absolute time or absolute time, thereby realizing a signal display that is free from time lag with respect to the schedule information provided to the outside. The holding time determined by the timer unit 27 is not limited to the execution seconds or remaining time, and may be determined based on the absolute time or absolute time.

[0021] The lamp driving unit 13 is an analog circuit that receives a lighting drive signal from the signal control circuit 25 and individually lights up the lamp elements constituting a specified specific traffic signal lamp SG among the multiple traffic signal lamps SG provided at the intersection CS. The lamp driving unit 13 has multiple input terminals corresponding to the individual lamp elements or a set of lamp elements constituting the multiple traffic signal lamps SG provided at the intersection CS, and includes multiple lamp switches (not shown) corresponding to the individual lamp elements or a set of lamp elements constituting the multiple traffic signal lamps SG.

[0022] The time acquisition unit 14 includes a receiver that receives radio waves transmitted from, for example, a GPS or other satellite positioning system, and a signal processing circuit that processes signals output from the receiver, and can calculate the current time at the location where the traffic signal control device 10 is installed as absolute time information or absolute clock information. The time acquisition unit 14 is not limited to one that uses a satellite positioning system, and may be one that receives standard radio waves for a radio-controlled clock. The time acquisition unit 14 may acquire and update the current time using a time distribution service via the Internet or the like, or a communication service via a mobile communication line. The time acquisition unit 14 may acquire and update the current time autonomously, or may acquire the current time in response to a request from the information processing device 21.

[0023] The communication device 50 is a data transmission / reception device for relaying, and communicates with the traffic signal control device 10, the vehicle VE, etc., and transfers digital data. The communication device 50 may be built into the information processing device 21. The communication device 50 may also be part of the functions of a control center or a management center (not shown) installed in a remote location that can be connected via a communication network.

[0024] The vehicle VE that is the support target of the signal system 100 is, for example, an autonomous vehicle. The vehicle VE has a vehicle device 60 for autonomous driving. The vehicle device 60 has a processor 61, a memory 62, a communication unit 63, and an interface 64. The processor 61 controls various operations of the vehicle device 60 according to a program recorded in the memory 62. The processor 61 receives schedule information and the like from the external distribution device 50 via the communication unit 63. The schedule information here includes the remaining time until the display of the current light color or the display of a series of subsequent light colors ends, or the absolute time or absolute time when the display of the current light color or the display of a series of subsequent light colors ends. The schedule information includes information that makes it possible to distinguish the traffic signal lamps SG (vehicle lamps SG1, SG2, and pedestrian lamps SG1a, SG2a) to be noted depending on whether the road on which the vehicle VE is traveling is the main road RA1 or the secondary road RA2. The processor 61 performs various controls for autonomous driving based on the received schedule information and the like. Furthermore, the arithmetic processing unit 61 outputs schedule information and the like to an interface 64 such as a display as a notice of a signal change.

[0025] An example of a normal operation of the traffic signal control device 10 will be described below with reference to FIG.

[0026] The information processing device 21 operates the time acquisition unit 14 to acquire the current time from a time source such as a satellite positioning system, and synchronizes the current time of the clock held by the information processing device 21 with the current time acquired from the time source (step S11). After that, the information processing device 21 calculates the scheduled number of seconds for one cycle for the traffic signal light SG, and stores the scheduled information in the storage device 21b (step S12). Next, the information processing device 21 prepares signal schedule information for the traffic signal light SG, transmits the schedule information to the communication device 50, and stores the schedule information in the storage device 21b (step S13). This schedule information is acquired by the vehicle VE connected to the communication device 50 so as to be able to communicate data. The schedule information, for example, specifies the current time at the time of transmission and specifies the scheduled number of seconds or remaining time of the current light color or the subsequent light color, but may specify the current time at the time of transmission and specify the absolute time or absolute time at which the display of the current light color or the subsequent light color will end.

[0027] In relation to the operation in step S13, the specific traffic signal lamp SG that the vehicle VE focuses on is, for example, the vehicle lamp SG1. In other words, the vehicle VE can extract only the items that correspond to the vehicle lamp SG1 that corresponds to the vehicle VE from the schedule information.

[0028] The information processing device 21 transmits time table information of the traffic signal lamp SG to the signal control circuit 25 (step S14), and the signal control circuit 25 stores the time table information received from the information processing device 21 in the storage unit 26 (step S21). Here, the time table information corresponds to a time table executed by the information processing device 21 to which current information has been added, but if the signal control circuit 25 has a corresponding time table, it may be only the number of seconds for each step in the time table instead of the time table executed by the information processing device 21. The time table information corresponds to the schedule information provided to the outside in step S12 and enables the execution of the schedule information.

[0029] The information processing device 21 transmits a synchronization signal for calibrating or correcting the timer unit 27 to the signal control circuit 25 (step S15), and the signal control circuit 25 corrects the operation of the timer unit 27 based on the synchronization signal received from the information processing device 21 (step S22). Here, the synchronization signal reflects the number of seconds for which the current light color is being executed. The corrected timer unit 27 can accurately count the number of seconds for which the current light color is being executed for a relatively short period of time, and the signal control circuit 25 can accurately grasp the number of seconds for which the current light color is being executed by the synchronization signal from the information processing device 21.

[0030] The information processing device 21 instructs the signal control circuit 25 to change the display of the light color based on the time managed by itself (step S16), and the signal control circuit 25 outputs a drive signal to the light driving unit 13 based on the command received from the information processing device 21, switches the display state of the traffic signal light device SG, changes it to the next indication (next combination of light color states) (from green to yellow, from yellow to red, ...), and executes one cycle of the time table (step S23). Here, the time managed by the information processing device 21 is determined from the scheduled number of seconds set in step S12, and is the end timing of the display of each light color displayed in cycle units of the time table. As a result, the end timing of the currently displayed light color or the subsequent light color matches the scheduled information transmitted to the outside in step S13, and corresponds to the absolute time or absolute time when the current light color or the subsequent light color ends. In other words, the information processing device 21 controls the display state of the specific traffic signal light device SG of interest according to the scheduled information provided to the external vehicle VE.

[0031] The above-described operation of the information processing device 21 is performed not only for the specific traffic signal lamp SG of interest, but also for all traffic signal lamps SG in parallel. That is, a command to change the light color is sent to each of the vehicle lamps SG1, SG2 and the pedestrian lamps SG1a, SG2a (step S16). In response to this, all the vehicle lamps SG1, SG2 and the pedestrian lamps SG1a, SG2a perform one cycle of normal operation to change the display state according to the time table. After that, the information processing device 21 returns to step S11 and repeats the same operation.

[0032] The information processing device 21 can transmit schedule information to the communication device 50 not only when the light color of the traffic signal light device SG is changed, but also between changes in the light color. In this case, for example, the remaining time rather than the scheduled number of seconds is transmitted to the outside as the schedule information, or the absolute time or clock time when the display of the current light color will end is transmitted to the outside.

[0033] Hereinafter, with reference to FIG. 5, a description will be given of a degenerate operation performed in a state in which the functions of the traffic signal control device 10 are partially restricted.

[0034] The information processing device 21 may have an abnormality in the CPU 21a that executes the software, and generates some abnormality information accordingly (step S31). In this case, the signal control circuit 25 cannot receive information or commands from the information processing device 21, and therefore performs an independent and autonomous operation temporarily. That is, the signal control circuit 25 switches its own operation from a normal operation according to the information processing device 21 to a default degenerate operation. At a transitional timing when the normal operation is switched to the default degenerate operation, the signal control circuit 25 performs a preliminary degenerate operation for controlling the display state of the traffic signal lamp SG according to the scheduled information already provided to the outside. An abnormality in the information processing device 21 is detected, for example, by utilizing a self-diagnosis function of the hardware of the information processing device 21, and the detected abnormality can be grasped by the signal control circuit 25. An abnormality in the information processing device 21 can also be made detectable by providing a self-diagnosis function to the software of the information processing device 21. Detection of an abnormality in the information processing device 21 also includes a case where the information processing device 21 does not respond despite a request from the signal control circuit 25.

[0035] When the signal control circuit 25 receives the abnormality information, it determines that an abnormality has occurred in the information processing device 21 (step S41), and starts a preliminary degenerate operation (step S1) described below.

[0036] The signal control circuit 25 reads out the time table information of the traffic signal light SG from the memory unit 26 (step S42), and checks the time of the timer unit 27 corrected in step S22 of Fig. 4 (step S43). Here, the time is checked at a predetermined time interval, and this predetermined time interval is set to be equal to or less than the allowable error of the display time, for example.

[0037] When the time count of the timer 27 indicates the passage of the number of seconds for each stage (YES in step S44), the signal control circuit 25 outputs a drive signal to the lamp drive unit 13 to switch the display state of the specific traffic signal lamp SG of interest to the next aspect, i.e., the next combination of light colors (step S45). After that, the signal control circuit 25 checks whether the cycle of the time table is completed (step S46), and if the cycle of the time table is not completed (NO in step S46), it switches the display state of the traffic signal lamp SG by stage. If the cycle of the time table is completed (YES in step S46), it determines whether the schedule has been executed (step S47), and if the schedule has not been executed (NO in step S47), it sets the timer and starts the cycle (step S43). Here, the reason for determining whether the schedule has been executed or not is that, for the vehicle lamp SG2 with the code 2 in the time table as shown in FIG. 3(A), it takes into consideration that the display switching corresponding to the schedule information provided to the outside cannot be executed unless the next cycle is executed. If the schedule is being executed (YES in step S47), the preliminary degeneration operation started by the signal control circuit 25 (step S1) is completed.

[0038] After completing the preliminary degenerate operation, the signal control circuit 25 proceeds to the default degenerate operation (step S2). That is, the signal control circuit 25 reads out a time table dedicated to the default degenerate operation from the storage unit 26 (step S51), and causes the timer unit 27 to start timing based on the cycle of the time table dedicated to the degenerate operation (step S52). The signal control circuit 25 checks the timing of the timer unit 27 (step S53). If the time of the timer unit 27 indicates the passage of a number of steps (YES in step S54), the signal control circuit 25 outputs a drive signal to the lamp driver 13, and switches the display state of the specific traffic signal lamp SG of interest to the next indication, that is, the next combination of light colors (step S55). Thereafter, the signal control circuit 25 checks whether the cycle of the time table dedicated to the degenerate operation has been completed (step S56), and if the cycle of the time table has not been completed (NO in step S56), it switches the display state of the traffic signal lamp SG in stages. If the cycle of the time table has been completed (YES in step S56), it determines whether to stop the display (step S57), and if the display is not to be stopped (NO in step S57), it sets the timer and starts the cycle (step S53). That is, the operations described as steps S53 to S56 (strictly speaking, the routine part of step S2) are repeated.

[0039] As described above, after the occurrence of an abnormality, the vehicle lights SG1, SG2 and the pedestrian lights SG1a, SG2a perform preliminary degenerate operation (step S1) in compliance with the schedule information provided from the outside while being synchronized with each other, and then the operation (step S2) described as steps S51 to S57 is started, and the routine part of step S2 is repeated. That is, the signal control circuit 25 performs preliminary degenerate operation according to the schedule information at the transitional timing (step S1) until the start of the default degenerate operation (step S2). As a result, the traffic signal lights SG go through a display state corresponding to the preliminary degenerate operation that apparently operates according to the schedule information, and then transition to a display state corresponding to the default degenerate operation that is not restricted by the schedule information.

[0040] In the above explanation, the operation of the information processing device 21 is performed by acquiring the current time from the time source for each cycle of the time table to perform time synchronization (step S11), but the current time can be acquired from the time source when the light color changes, for example, or the frequency of acquiring the current time from the time source can be lower than the cycle of the time table. The process of calculating and storing the scheduled number of seconds for one cycle (step S12) and the process of preparing and transmitting scheduled information for signals to the outside (step S13) can also be performed in units of light color change, not limited to the timing of each cycle of the time table.

[0041] In the above description, in step S14, the information processing device 21 transmits the time table information to the signal control circuit 25. However, as for the current information of the time table information, instead of the execution seconds or remaining seconds of the current light color, the absolute time at which the display of the current light color ends may be transmitted. In this case, in step S21, the signal control circuit 25 stores the absolute time at which the display of the current light color ends, received from the information processing device 21, in the storage unit 26, and in step S22, the signal control circuit 25 corrects the absolute time that the timer unit 27 updates and holds, based on the synchronization signal received from the information processing device 21. Also, in step S44, the signal control circuit 25 checks the absolute time that the timer unit 27 updates and holds. That is, in the preliminary degenerate operation (step S1), the timing of switching the display is determined by the absolute time, not the scheduled number of seconds.

[0042] In the above explanation, the preliminary degeneration operation (step S1) is executed in cycle units of the time table, but the preliminary degeneration operation can be terminated at the stage where the light color displayed by each traffic signal light SG immediately before the abnormality occurred is executed according to the scheduled information, and then the default degeneration operation can be executed by switching to the corresponding stage of the time table dedicated to the degeneration operation.

[0043] Fig. 6(A) is a chart for explaining normal operation, preliminary degenerate operation, and default degenerate operation. Until an abnormality occurs at time T1, a normal operation mode OP0 is executed under the control of the information processing device 21 to operate the lamp driving unit 13 and the traffic signal lamp SG (specifically, see Fig. 4). When a transitional timing TMtr occurs due to an abnormality occurring in the information processing device 21, a transition is made to a preliminary degenerate operation mode OP1 under the control of the signal control circuit 25, in which a preliminary degenerate operation (specifically, see step S1 in Fig. 5) is executed with consistency by matching the switching time with the normal operation mode OP0. In other words, the signal control circuit 25 controls the display state of the traffic signal lamp SG according to the scheduled information provided to the outside. After that, when the transitional timing TMtr bound by the scheduled information provided to the outside ends, under the control of the signal control circuit 25, a time table dedicated to the default degenerate operation stored in the memory unit 26 is read out, and the system transitions to a default degenerate operation mode OP2 in which the default degenerate operation (specifically, see step S2 in FIG. 5) is repeated based on this time table.

[0044] Fig. 6(B) is a diagram explaining a time table dedicated to degenerate operation, and Fig. 6(C) is a table of the planned number of seconds calculated from the time table of Fig. 6(B). Comparing Fig. 6(B) with Fig. 3(A), the number of seconds for steps 1 and 6 has been reduced, and the number of seconds for blue and red display has been shortened in the default degenerate operation.

[0045] The traffic signal control device 10 of the first embodiment described above includes an information processing device 21 that creates schedule information regarding switching of signal indications, a communication device 22 that provides the schedule information to the outside, a signal control circuit 25 that controls the display state of the traffic signal lights SG based on commands from the information processing device 21, and a memory unit 26 that holds the schedule information, and the signal control circuit 25 controls the display state of the traffic signal lights SG in accordance with the schedule information at the transitional timing TMtr at which the traffic signal control circuit 25 switches from normal operation according to the information processing device 21 to a default degenerate operation.

[0046] In the above-mentioned traffic signal control device 10, the signal control circuit 25 controls the display state of the traffic signal lights SG in accordance with the scheduled information at the transitional timing TMtr when the signal control circuit 25 switches from normal operation in accordance with the information processing device 21 to a predetermined degenerate operation. Therefore, even if for some reason the control is switched from the information processing device 21 to degenerate operation by the signal control circuit 25, the traffic light or the multiple traffic signal lights SG that constitute it will operate in accordance with the scheduled information provided externally at the transitional timing TMtr, thereby preventing any disruption to the operation of the vehicle VE that has received the information.

[0047] Furthermore, the traffic signal control method of the first embodiment is a traffic signal control method in a traffic signal control device 10 that includes an information processing device 21 that creates scheduled information regarding switching of signal aspects to be provided to the outside, and a signal control circuit 25 that controls the display state of the traffic signal lights SG based on commands from the information processing device 21, and controls the display state of the traffic signal lights SG in accordance with the scheduled information provided to the outside at a transitional timing TMtr when normal operation according to the information processing device 21 is switched to a default degenerate operation by the signal control circuit 25.

[0048] Particularly in the case of the traffic signal control device 10 of the first embodiment, the default degenerate operation after the transitional timing TMtr is based on a time table prepared in advance. The time table prepared in advance means a time table prepared for the degenerate operation and stored in the memory unit 26. In this case, regardless of the content of the immediately preceding normal operation, the traffic signal lamp SG can be caused to perform the lighting operation and the switching operation at the operation cycle and timing of the time table prepared in advance for safety purposes.

[0049] Second Embodiment Hereinafter, an example of a traffic signal control device etc. according to the second embodiment will be described with reference to Figs. 7 and 8. In the second embodiment, the description of the same matters as in the first embodiment etc. will be omitted. In the case of the second embodiment, even if the device transitions to the default degenerate operation, the device continues to operate in the same manner as in the transitional timing.

[0050] Fig. 7 is a diagram for explaining the operation of the traffic signal control device 10 of the second embodiment. In this case, as shown in Fig. 7, in step S251 of step S2 corresponding to the default degenerate operation, the signal control circuit 25 reads out the time table information obtained in step S21 of Fig. 4 from the storage unit 26, instead of the time table dedicated to the default degenerate operation.

[0051] Fig. 8 is a chart for explaining normal operation, preliminary degenerate operation, and default degenerate operation in the second embodiment. Until an abnormality occurs at time T1, a normal operation mode OP0 is executed under the control of the information processing device 21 to operate the lamp driving unit 13 and the traffic signal lamp SG (specifically, see Fig. 4). When a transitional timing TMtr occurs due to an abnormality occurring in the information processing device 21, a transition is made to a preliminary degenerate operation mode OP1 under the control of the signal control circuit 25, in which a preliminary degenerate operation (specifically, see step S1 in Fig. 7) is executed with consistency by matching the switching time with the normal operation mode OP0. In other words, the signal control circuit 25 controls the display state of the traffic signal lamp SG according to the scheduled information already provided to the outside. After that, when the transitional timing TMtr bound by the scheduled information provided externally ends, under the control of the signal control circuit 25, the time table information corresponding to the immediately preceding operation stored in the memory unit 26 is read out, and the system transitions to a default degenerate operation mode OP2 in which the default degenerate operation (specifically, see step S2 in FIG. 7) is repeated based on the scheduled number of seconds for each of these colors.

[0052] In the case of the traffic signal control device 10 of the second embodiment, the default degenerate operation after the transitional timing TMtr is similar to the traffic signal information corresponding to the schedule information provided externally, and is specifically based on the time table information stored in the memory unit 26, i.e., a table of the scheduled seconds for each color. The traffic signal information corresponding to the schedule information provided externally reproduces the operation cycle corresponding to the most recent schedule. In this case, the traffic signal control circuit 25 continues the operation cycle including the display time immediately before the transitional timing TMtr. In other words, the traffic signal control circuit 25 causes the traffic signal lamp SG to perform the lighting operation and the switching operation with the operation cycle and timing that maintains the immediately previous normal operation.

[0053] Third Embodiment Hereinafter, a traffic signal control device and the like according to the third embodiment will be described with reference to Figs. 9 to 11. In the third embodiment, the same matters as those in the first embodiment and the like will not be described. In the case of the third embodiment, the scheduled information provided to the outside does not notify a specific time but notifies a time range.

[0054] A traffic signal control device 10 according to a third embodiment will be described with reference to Fig. 9. The traffic signal control device 10 and the traffic signal light SG driven thereby are vehicle-sensitive traffic lights. The traffic signal control device 10 includes a sensor 31 that detects the stop of an automobile, for example, around a stop line corresponding to the traffic signal light SG. When the traffic signal control device 10 detects the stop of a vehicle VE by the sensor 31, it switches the light color of the traffic signal light SG that the vehicle VE faces from red to green after a certain time has elapsed.

[0055] 10 and 11 are diagrams for explaining the operation of the traffic signal control device 10 of the third embodiment. In this case, as shown in FIG. 10, in step S312, the information processing device 21 calculates a planned second range, i.e., a time width, for one cycle for the traffic signal light SG. The planned second range, i.e., a time width, includes a lower limit time and an upper limit time for switching from a current light color (e.g., red) to a next light color (e.g., green) permitted by this vehicle-sensitive traffic light. In step S314, the information processing device 21 transmits time table information including the planned second range for the traffic signal light SG to the signal control circuit 25, and in step S321, the signal control circuit 25 stores the time table information received from the information processing device 21 in the storage unit 26. In step S316, the information processing device 21 instructs the signal control circuit 25 to change the display of the light color after a predetermined shortest time from the vehicle detection timing, i.e., at a time reflecting the sensing result, according to the vehicle detection result using the sensor 31. Here, the predetermined shortest time corresponds to the lower limit of the expected range of seconds, that is, the time span, calculated in step S312.

[0056] As shown in Fig. 11, when an abnormality occurs in the information processing device 21, in step S342, the signal control circuit 25 reads the time table information of the traffic signal light SG from the memory unit 26, determines the longest time from the expected second range, i.e., the time width, and rewrites the stage of the time table to the longest time. In the subsequent step S44, it is determined whether the time count of the timer 27 indicates that the longest time has elapsed. That is, the signal control circuit 25 waits for the longest time to elapse, and then outputs a drive signal to the light driver 13 to change the display state of the traffic signal light SG, specifically the display state of the traffic signal light SG corresponding to the sensor 31, to a state that displays the next light color (specifically, from red to green) (step S45).

[0057] In the case of the traffic signal control device 10 of the third embodiment, the scheduled information distributed to the outside in step S312 has a time width regarding the timing of switching the signal aspect, and at the transitional timing TMtr, the display state of the traffic signal light device SG is switched for the longest time of the time width. When scheduled information regarding the switching of the signal aspect is provided with an unclear time width such as in the case of sensitive control, the transitional operation can be ensured in terms of ensuring safety by switching for the longest time of the time width.

[0058] The traffic signal control device 10 of the third embodiment can be applied not only to semi-sensor-type traffic lights but also to full-sensor-type traffic lights.

[0059] In the example described above, the display state of the traffic signal lamp SG is changed to the next light color state in the longest time of the time width at the transitional timing TMtr, but the display state of the traffic signal lamp SG can also be changed to the next light color state in a standard time shorter than the longest time of the time width, or in the shortest time. In this case, too, the traffic light or the multiple traffic signal lamps SG that constitute it operate according to the scheduled information provided to the outside at the transitional timing TMtr, so that it is possible to prevent any disruption to the operation of the vehicle VE that has received the provided information.

[0060] 〔others〕 The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the present invention.

[0061] The transition from the normal operation to the transitional timing TMtr is not limited to the case where an abnormality occurs in the information processing device 21.

[0062] In the above embodiment, the shape of the road RA shown in Fig. 1 is merely an example, and the present invention is applicable to various shapes and structures. That is, the intersection CS where the traffic signal control device 10 and the traffic signal lamps SG are installed is not limited to a four-way intersection, but may be a three-way intersection, a five-way intersection, or the like. [Explanation of symbols]

[0063] 10...traffic signal control device, 13...light driving unit, 14...time acquisition unit, 21...information processing device, 21a...CPU, 21b...storage device, 25...signal control circuit, 26...storage unit, 27...timekeeping unit, 31...sensor, 50...communication device, 60...vehicle device, 61...arithmetic processing unit, 62...memory, 63...communication unit, 64...interface, 100...signal system, CS...intersection, OP0...normal operation mode, OP1...preliminary degenerate operation mode, OP2...default degenerate operation mode, RA...road, SG...traffic signal light, SG1,SG2...vehicle light, SG1a,SG2a...pedestrian light, TMtr...transient timing

Claims

1. An information processing device that creates schedule information regarding switching of signal aspects; a communication device for providing the schedule information to an external device; a signal control circuit for controlling a display state of a traffic signal lamp based on a command from the information processing device; A storage unit for storing the schedule information, the signal control circuit controls the display state of the traffic signal lamp according to the scheduled information at a transitional timing when the normal operation according to the information processing device is switched to a default degenerate operation; Traffic signal control device.

2. The traffic signal control device according to claim 1 , wherein the signal control circuit performs the default degenerate operation that is not limited by the scheduled information after the transitional timing when it determines that an abnormality has occurred in the operation of the information processing device.

3. The traffic signal control device according to claim 1 , wherein the signal control circuit performs a preliminary degenerate operation in accordance with the schedule information during the transitional timing.

4. The traffic signal control device according to claim 1 , wherein the predetermined degenerate operation after the transitional timing is based on either a pre-prepared time table or signal information corresponding to the schedule information provided externally.

5. a timer unit that enables determination of a duration for which the current display state of the traffic signal lamp is maintained, The traffic signal control device according to claim 1 , wherein the timekeeping unit receives a synchronization signal from the information processing device before the transitional timing and corrects either the elapsed time or the absolute time.

6. 2. The traffic signal control device according to claim 1, wherein, when the scheduled information has a time width with respect to a switching timing of a signal aspect, the signal control circuit switches the display state of the traffic signal lamp in the shortest time of the time width at the transitional timing.

7. The traffic signal control device according to claim 1 , further comprising a lamp driving unit that operates the traffic signal lamps based on a lighting drive signal output from the signal control circuit.

8. A traffic signal control method in a traffic signal control device including an information processing device that creates schedule information related to switching of signal aspects to be provided to an outside, and a signal control circuit that controls a display state of a traffic signal lamp based on a command from the information processing device, comprising: A traffic signal control method for controlling the display state of the traffic signal lamp in accordance with the scheduled information provided externally at a transitional timing when normal operation according to the information processing device is switched to a predetermined degenerate operation by the signal control circuit.

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