JP2006113784A - Traffic light controller and traffic light system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize traffic light control more rapidly following a sharp fluctuation of a traffic situation while reducing influence of a fluctuation error of a traffic flow by a change of a traffic light color. <P>SOLUTION: A central device 1 and a terminal device 11 control traffic signals a1, a2, b1, b2 installed in a crossing CR1. The devices 1, 11 obtain traffic situation information from vehicle sensors g1-g4 of respective inlets of the crossing CR1. The central device 1 obtains a split and a cycle length of the crossing CR1 on the basis of the information. The central device 1 and the terminal device 11 control the traffic signals according to a value of the split and the cycle length. The central device 1 obtains the value of the split and the cycle length of the crossing CR1 to be reflected in each cycle on the basis of the information of a period between prescribed intermediate timing in a cycle two cycles before the cycle and prescribed intermediate timing in a cycle one cycle before the cycle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a traffic signal control device for controlling a traffic signal device, and a traffic signal system using the traffic signal control device.

  In a conventional traffic signal control device, when performing point control to control a traffic signal at a certain intersection without linking it to traffic signals at other intersections, traffic status information (for example, traffic volume etc.) of each inflow path to the intersection ), Two types of signal control parameters, ie, cycle length and split, are acquired, and the traffic signal is controlled according to the signal control parameters. Here, the cycle length is the time from the start of the green signal display of the traffic signal for one of the intersecting roads to the start of the next green signal display of the traffic signal. A split is the length of time allotted to each presentation within one cycle.

  In addition, when system control is performed to control traffic signals at a plurality of intersections in a control area, the three types of cycle length, split, and offset at each intersection are determined based on the traffic situation information related to the control area. The traffic signal was controlled and the traffic signal was controlled according to this signal control parameter. Here, the offset is a temporal relative relationship between the respective intersections.

Conventionally, each collection period of traffic situation information in the case of point control, and each collection period of traffic situation for determining the cycle length and split of a predetermined intersection (so-called important intersection) in the case of system control are, for example, the following patent documents As disclosed in 1, it was consistent with each cycle of the intersection. That is, the cycle length and split of the subsequent cycle are determined based on the traffic status information during the period from the start to the end of a certain cycle. In this way, when the traffic condition information collection period is made to coincide with the cycle, the traffic flow fluctuation error due to the change in the signal lamp color is compared with the case where the traffic condition information collection period is set to a predetermined time (for example, 5 minutes) regardless of the cycle. It is preferable because it can collect information with less influence.
Japanese Patent No. 2687173

  However, in the conventional traffic signal control device, the cycle length and split of the subsequent cycle are determined based on the traffic status information during the period from the start to the end of a certain cycle, so the cycle is based on the traffic status information. Since the process for determining the length and split takes some time, the cycle length and split of a cycle must be determined at the latest based on traffic condition information in the cycle two cycles before the cycle. become. Therefore, in the conventional traffic signal control device, even if the traffic situation fluctuates suddenly, it cannot follow this quickly. This point will be described in detail in connection with a comparative example described later.

  The present invention has been made in view of such circumstances, and traffic signal control that more quickly follows sudden changes in traffic conditions while reducing the influence of traffic flow fluctuation errors due to changes in signal lamp color. It is an object of the present invention to provide a traffic signal control apparatus capable of realizing the above and a traffic signal system using the traffic signal control apparatus.

  In order to solve the above-described problem, a traffic signal control device according to a first aspect of the present invention is a traffic signal control device that controls a traffic signal installed at a road intersection. Traffic condition information obtaining means, signal control parameter obtaining means for obtaining a value of a signal control parameter based on the traffic condition information obtained by the traffic condition information obtaining means, and signal obtained by the signal control parameter obtaining means Means for controlling the traffic signal according to the value of the control parameter, and the signal control parameter acquisition means is reflected in each cycle of the traffic signal with respect to a predetermined type of parameter among the signal control parameters. Each value of the predetermined type of parameter to be stored is set to an intermediate predetermined timing in the cycle two cycles before the current cycle. Based on the traffic condition information of the period between the middle of the predetermined timing in the previous cycle of the cycle, it is what you get.

  According to the first aspect, since each value of the predetermined type of parameter to be reflected in each cycle is obtained based on the traffic condition information of the period, it is newer than the conventional traffic signal control device. Traffic status information can be reflected in the control of each cycle. Therefore, according to the first aspect, it is possible to realize traffic signal control that more quickly follows a sudden change in traffic conditions, and further reduces the occurrence of traffic jams and wasteful green time. be able to.

  In addition, according to the first aspect, since the traffic condition information of the period is used, the influence of the traffic flow fluctuation error due to the change in the signal light color can be reduced as in the conventional traffic signal control device. it can.

  The traffic signal control apparatus according to a second aspect of the present invention is the traffic signal control apparatus according to the first aspect, wherein the traffic condition information is traffic condition information of each inflow path to the intersection. This 2nd aspect gives the example of traffic condition information.

  A traffic signal control device according to a third aspect of the present invention is a traffic signal control device that performs system control on traffic signal devices installed respectively at a plurality of road intersections in a control area, and is related to the control area. Traffic condition information acquisition means for obtaining the traffic condition information, signal control parameter acquisition means for obtaining the value of the signal control parameter of each road intersection based on the traffic condition information obtained by the traffic condition information acquisition means, Means for controlling the traffic signal at each road intersection according to the value of the signal control parameter obtained by the signal control parameter acquisition means, and the signal control parameter acquisition means includes the plurality of road intersections. Each cycle of the traffic signal at the predetermined intersection with respect to a predetermined type of signal control parameters at the predetermined intersection. Each value of the predetermined type of parameter to be reflected in the period, between the intermediate predetermined timing in the cycle two cycles before the cycle and the intermediate predetermined timing in the cycle one cycle before the cycle, It is obtained based on predetermined information in the traffic situation information.

  The third aspect is an example of a traffic signal control apparatus that performs system control. According to the third aspect, as in the first aspect, the influence of a traffic flow fluctuation error due to a change in signal lamp color. It is possible to realize traffic signal control that more quickly follows a sudden change in traffic conditions while reducing the traffic.

  The traffic signal control apparatus according to a fourth aspect of the present invention is the traffic signal control apparatus according to the third aspect, wherein the predetermined information is traffic state information of each inflow path to the predetermined intersection. In the fourth aspect, an example of the predetermined information is given.

  The traffic signal control apparatus according to a fifth aspect of the present invention is the traffic signal control apparatus according to any one of the first to fourth aspects, wherein the predetermined types of parameters are cycle length and split. In the fourth aspect, an example of the predetermined type of parameter is given.

  In the traffic signal control apparatus according to a sixth aspect of the present invention, in any one of the first to fifth aspects, the intermediate predetermined timing is a start time of the last step of the cycle. At the last stage, traffic lights in all directions of the intersection are usually turned red and vehicles do not pass through the intersection, so the traffic situation information for the period approaches the traffic situation information for the period that matches the cycle. preferable. However, in the first to fifth aspects, the intermediate predetermined timing may be a time before the start of the last step of the cycle, or the processing of the traffic situation information is completed by the start of the next cycle. If possible, it may be in the middle of the last stage of the cycle.

  A traffic signal system according to a seventh aspect of the present invention includes the traffic signal control device according to any one of the first to sixth aspects and the traffic signal device.

  ADVANTAGE OF THE INVENTION According to this invention, the traffic signal control apparatus which can implement | achieve the traffic signal control which followed the rapid fluctuation | variation of the traffic condition more rapidly, reducing the influence of the fluctuation | variation error of the traffic flow by the change of a signal lamp color. And a traffic signal system using the same can be provided.

  Hereinafter, a traffic signal control apparatus and a traffic signal system using the same according to the present invention will be described with reference to the drawings.

  [First Embodiment]

  FIG. 1 is a schematic block diagram showing a traffic signal system according to a first embodiment of the present invention. FIG. 2 is a schematic plan view schematically showing the arrangement of traffic signals and the like at intersections CR1 to CR3 in the control area of this traffic signal system.

  As shown in FIG. 2, the traffic signal system according to the present embodiment has a system control in which an area including three intersections CR1 to CR3 where one road 100 and three roads 101 to 103 intersect is a control area. I do. In the present embodiment, the intersection CR1 is an important intersection.

  As shown in FIGS. 1 and 2, the traffic signal system according to the present embodiment includes two 1-display vehicle traffic lights a1, 2 2-display-vehicle traffic lights a2, and 4 The pedestrian traffic light b1 and the four 2-display pedestrian traffic lights b2, the two 1-display vehicle traffic lights c1, the two 2-display-vehicle traffic lights c2, and the 4 1-display display installed at the intersection CR2. Pedestrian traffic light d1 and four two-display pedestrian traffic lights d2, two one-display vehicle traffic lights e1, two two-display vehicle traffic lights e2, and four one-display walks installed at intersection CR3 A traffic signal f1 and four traffic lights for two pedestrians f2 are provided as traffic signals.

  The traffic lights a1, a2, b1, and b2 at the intersection CR1 are controlled so that the lighting states are sequentially switched as shown in FIG. 3 during one cycle and are controlled to repeat this cycle. FIG. 3 is a time chart showing lighting states for one cycle of the traffic lights a1, a2, b1, and b2 at the intersection CR1. In the present embodiment, as shown in FIG. 3, one cycle is composed of ten steps (steps) from the first to the tenth (the last), and the display seconds of the first and the sixth are shown. Only the number is variable and is determined according to the signal control parameter, and the display seconds of the other tiers are fixed to a predetermined number of seconds and are not changed in any cycle. The 1st to 5th ladders are shown as 1 and the 6th to 10th ladders are shown as 2 signs. The same applies to the traffic lights c1, c2, d1, d2 at the intersection CR2 and the traffic lights e1, e2, f1, f2 at the intersection CR3.

  In addition, as shown in FIGS. 1 and 2, the traffic signal system according to the present embodiment includes an ultrasonic vehicle sensor that senses a vehicle at a predetermined position upstream of each of the inflow paths r1 to r4 of the important intersection CR1. Ultrasonic vehicles for sensing vehicles at predetermined positions upstream of the vehicle detectors g1 to g4 and the inflow path r5 of the intersection CR2 and the inflow path r6 of the intersection CR3, which are upstream and downstream inflow paths with respect to the control area, respectively. Vehicle sensors g5 and g6 such as sensors.

  Furthermore, as shown in FIG. 1, the traffic signal system according to the present embodiment includes a central device 1, a terminal device 11 for an intersection CR1, a terminal device 12 for an intersection CR2, and a terminal device 13 for an intersection CR3. It has. The central device 1 is configured by, for example, a computer, and the terminal devices 11 to 13 are configured by, for example, a drive circuit that drives and lights a computer and a traffic signal at a corresponding intersection.

  The terminal device 11 mainly collects the sensing information of the vehicle sensors g1 to g4 and transmits the sensing information to the central device 1 in response to the sensing information request from the central device 1, and the central device 1 Has a function of controlling the traffic lights a1, a2, b1, b2 at the intersection CR1 in accordance with the value of the signal control parameter transmitted from. Similarly, the terminal device 12 mainly collects the sensing information of the vehicle detector g5 and transmits the sensing information to the central device 1 in response to a sensing information request from the central device 1, and the central device 1 Has a function of controlling the traffic lights c1, c2, d1, d2 at the intersection CR2 in accordance with the value of the signal control parameter transmitted from. Similarly, the terminal device 13 mainly collects the sensing information of the vehicle sensor g6 and transmits the sensing information to the central device 1 in response to the sensing information request from the central device 1, and the central device 1 And the function of controlling the traffic lights e1, e2, f1, f2 at the intersection CR3 in accordance with the value of the signal control parameter transmitted from.

  The central device 1 mainly determines the signal control parameter values for the intersections CR1 to CR3 based on the sensing information transmitted from the terminal devices 11 to 13, and determines the values of these signal control parameters as the terminal devices. It has the function to transmit to 11-13.

  Next, the operation of the terminal device 11 for the important intersection CR1 will be described with reference to FIGS. FIG. 4 is a schematic flowchart showing a main routine of the terminal device 11, and FIGS. 5 to 7 are schematic flowcharts showing each interrupt processing of the terminal device 11.

  When the operation starts, the terminal device 11 first initializes as shown in FIG. 4 (step S1). As the initialization, the terminal device 11 stores vehicle detection count values A1 to A4, detected vehicle number count values B1 to B4, and vehicle detection flags R1 to R4 stored in an internal memory (not shown), respectively. Set to zero. Values A1, B1, R1 correspond to the vehicle sensor g1, values A2, B2, R2 correspond to the vehicle sensor g2, values A3, B3, R3 correspond to the vehicle sensor g3, values A4, B4, R4 corresponds to the vehicle sensor g4. As can be seen from the description of the interrupt processing shown in FIG. 5 described later, the vehicle detection count values A1 to A4 indicate count values (cumulative values) of the number of times the corresponding vehicle detector has detected the vehicle. The detected vehicle number count values B1 to B4 indicate the count value (cumulative value) of the number of vehicles detected by the corresponding vehicle detector. The vehicle detection flags R1 to R4 are flags indicating whether or not the corresponding vehicle detector has detected the vehicle at the previous sampling. If it is “1”, it indicates that the vehicle was detected last time. Indicates that it was not detected last time.

  Next, the terminal device 11 determines whether or not the initial signal control parameters (cycle length, split, offset) have been received from the central device 1 (step S2). The process proceeds to step S3. This initial signal control parameter is a predetermined signal control parameter.

  Next, in step S3, the terminal device 11 sets the display seconds of each floor for one cycle according to the initial signal control parameters (cycle length, split, offset) received from the central device 1, Store in memory.

  Thereafter, the terminal device 11 performs signal control (see FIG. 3) for one cycle (from FIG. 3) to the important intersection CR1 according to the display seconds of each floor for one cycle that is set the latest. For the traffic lights a1, a2, b1 and b2 (step S4). In the middle of the signal control for one cycle, the terminal device 11 transmits a final floor start timing signal to the central device 1 at the start of the final floor (in this embodiment, the 10th floor).

  When the signal control for one cycle in step S4 ends, the process returns to step S4, and the signal control for one cycle in step S4 is repeated.

  When performing signal control for one cycle in the first and second steps S4, the display seconds of each step for the most recently set one cycle are the display seconds set in step S3. When signal control for one cycle of step S4 is performed after the third time, the latest display seconds of each floor for one cycle are the latest set in step S22 in FIG. 7 to be described later. In seconds.

  The process that repeats step S4 through steps S1 to S3 described above is the main routine of the terminal device 11.

  The terminal device 11 performs sensing information collection processing shown in FIG. 5 as interrupt processing during processing of the main routine. This sensing information collection process is performed every unit time T1 (for example, 50 mS).

  When the terminal device 11 starts the sensing information collection process shown in FIG. 5, first, of the vehicle detectors g1 to g4, one vehicle for which the processes after step S12 have not yet been performed in the current sensing information collection process. The sensor gm is selected (step S11).

  Next, the terminal device 11 determines whether or not the vehicle sensor gm selected most recently in step S11 senses the vehicle (step S12). If it is determined in step S12 that it is not detected, the terminal device 11 sets the corresponding vehicle detection flag Rm to 0 (step S17), and then proceeds to step S18. On the other hand, if it is determined in step S12 that sensing is performed, the process proceeds to step S13.

  In step S13, the terminal device 11 increments the corresponding vehicle detection count value Am by 1.

  Subsequently, the terminal device 11 determines whether or not the corresponding vehicle detection flag Rm is 0 (whether the vehicle detector gm has detected the vehicle at the time of the previous sampling (at the time of the previous detection information collection process)). (Step S14). If the vehicle detection flag Rm is 0, the process proceeds to step S15. On the other hand, if the vehicle detection flag Rm is not 0, the process proceeds to step S16.

  In step S15, the terminal device 11 increments the corresponding sensed vehicle number count value Bm by one. Thereafter, the process proceeds to step S16.

  In step S16, the terminal device 11 sets the corresponding vehicle detection flag Rm to 1. Thereafter, the process proceeds to step S18.

  In step S18, the terminal device 11 determines whether or not the processing after step S12 has been completed for all the vehicle detectors g1 to g4 (S18). If not completed, the process returns to step S11. If completed, the current sensing information collection process is terminated and the process returns to the main routine shown in FIG.

  Further, the terminal device 11 performs a sensing information transmission process shown in FIG. 6 as an interrupt process during the process of the main routine shown in FIG. This sensing information transmission process is performed every time the terminal device 11 receives a sensing information request from the central device 1.

  When the terminal device 11 starts the sensing information transmission process shown in FIG. 6, the current vehicle sensing number count values A1 to A4 and the current sensing vehicle number count values B1 to B4 are sent to the central device 1 as sensing information. (Step S21). Thereafter, the current sensing information transmission process is terminated, and the process returns to the main routine shown in FIG.

  Further, the terminal device 11 performs a signal control parameter reception process shown in FIG. 7 as an interrupt process during the process of the main routine shown in FIG. This signal control parameter reception process is performed each time the terminal device 11 receives the second and subsequent signal control parameters from the central device 1 (that is, signal control parameters other than the initial signal control parameters).

  When the terminal device 11 starts the signal control parameter reception process shown in FIG. 7, the terminal device 11 sets the display seconds of each step for one cycle according to the signal control parameters (cycle length, split, offset) received from the central device 1. These are stored in the internal memory (step S22). Thereafter, the current signal control parameter reception process is terminated, and the process returns to the main routine shown in FIG.

  Next, operation | movement of the terminal device 12 for intersection CR2 is demonstrated with reference to FIG. 8 thru | or FIG. FIG. 8 is a schematic flowchart showing a main routine of the terminal device 12, and FIGS. 9 to 11 are schematic flowcharts showing each interrupt processing of the terminal device 12.

  When the operation starts, the terminal device 12 first performs initialization as shown in FIG. 8 (step S31). As the initialization, the terminal device 12 sets the vehicle detection count value A5, the detected vehicle number count value B5, and the vehicle detection flag R5 stored in an internal memory (not shown) to zero. The values A5, B5, R5 correspond to the vehicle detector g5. As can be seen from the description of the interrupt process shown in FIG. 9 described later, the vehicle detection count value A5 indicates the count value (cumulative value) of the number of times the corresponding vehicle detector g5 has detected the vehicle. The sensed vehicle number count value B5 indicates the count value (cumulative value) of the number of vehicles sensed by the corresponding vehicle sensor g5. The vehicle detection flag R5 is a flag indicating whether or not the corresponding vehicle detector g5 has detected the vehicle at the previous sampling. If it is “1”, it indicates that the vehicle was detected last time. Indicates not detected.

  Next, the terminal device 12 determines whether or not the initial signal control parameters (cycle length, split, offset) have been received from the central device 1 (step S32). Control goes to step S33. This initial signal control parameter is a predetermined signal control parameter.

  Next, in step S33, the terminal device 12 sets the display seconds of each floor for one cycle in accordance with the initial signal control parameters (cycle length, split, offset) received from the central device 1, and stores them in the internal unit. Store in memory.

  After that, the terminal device 12 performs signal control for one cycle (from the first floor to the tenth floor) according to the display seconds of each floor for one cycle that is set the latest, and the traffic signals c1, c2, at the intersection CR2. This is performed for d1 and d2 (step S34). Unlike the case of the terminal device 11, the final floor start timing signal is not transmitted to the central device 1 during the signal control for one cycle.

  When the signal control for one cycle in step S34 ends, the process returns to step S34, and the signal control for one cycle in step S34 is repeated.

  When the signal control for one cycle in the first and second steps S34 is performed, the display seconds of each step for the most recently set one cycle are the display seconds set in step S33. When the signal control for one cycle of step S34 is performed after the third time, the latest display time of each floor for one cycle is the latest set in step S52 in FIG. In seconds.

  The process that repeats step S34 through steps S31 to S33 described above is the main routine of the terminal device 12.

  The terminal device 12 performs sensing information collection processing shown in FIG. 9 as interrupt processing during processing of the main routine. This sensing information collection process is performed every unit time T1 (for example, 50 mS).

  When starting the sensing information collection process shown in FIG. 9, the terminal device 12 first determines whether or not the vehicle sensor g5 senses a vehicle (step S41). If it is determined in step S41 that no sensing has been performed, the terminal device 12 sets the corresponding vehicle sensing flag R5 to 0 (step S46), and then ends the current sensing information collection process, and the main device shown in FIG. Return to the routine. On the other hand, if it is determined in step S41 that sensing is performed, the process proceeds to step S42.

  In step S42, the terminal device 12 increments the corresponding vehicle detection count value A5 by one.

  Subsequently, the terminal device 12 determines whether or not the corresponding vehicle detection flag R5 is 0 (whether the vehicle sensor g5 has detected the vehicle during the previous sampling (during the previous detection information collection process)). (Step S43). If the vehicle detection flag R5 is 0, the process proceeds to step S44. On the other hand, if the vehicle detection flag R5 is not 0, the process proceeds to step S45.

  In step S44, the terminal device 12 increments the corresponding sensed vehicle number count value B5 by one. Thereafter, the process proceeds to step S45.

  In step S45, the terminal device 12 sets the corresponding vehicle detection flag R5 to 1. Thereafter, the current sensing information collection process is terminated, and the process returns to the main routine shown in FIG.

  Further, the terminal device 12 performs a sensing information transmission process shown in FIG. 10 as an interrupt process during the process of the main routine shown in FIG. This sensing information transmission process is performed every time the terminal device 12 receives a sensing information request from the central device 1.

  When the sensing information transmission process shown in FIG. 10 is started, the terminal device 12 transmits the current vehicle sensing count value A5 and the current sensing vehicle number count value B5 as sensing information to the central device 1 (step S51). . Thereafter, the current sensing information transmission process is terminated, and the process returns to the main routine shown in FIG.

  Further, the terminal device 12 performs a signal control parameter reception process shown in FIG. 11 as an interrupt process during the process of the main routine shown in FIG. This signal control parameter reception process is performed every time the terminal device 12 receives the second and subsequent signal control parameters from the central device 1 (that is, signal control parameters other than the initial signal control parameters).

  When the terminal device 12 starts the signal control parameter reception process shown in FIG. 11, the terminal device 12 sets the display seconds of each floor for one cycle according to the signal control parameters (cycle length, split, offset) received from the central device 1. These are stored in the internal memory (step S52). Thereafter, the current signal control parameter reception process is terminated, and the process returns to the main routine shown in FIG.

  The operation of the terminal device 13 is the same as the operation of the terminal device 12 described above. As for the operation of the terminal device 13, in the explanation of the operation of the terminal device 12 and FIGS. 8 to 11, the terminal device 12 is the terminal device 13, the intersection CR2 is the intersection CR3, and the vehicle detection count value A5 is the vehicle detection count. Count value A6, sensed vehicle number count value B5, sensed vehicle number count value B6, vehicle sensing flag R5, vehicle sensing flag R6, vehicle sensor g5, vehicle sensor g6, traffic lights c1, c2, d1, d2 Should be read as traffic lights e1, e2, f1, and f2, respectively.

  Next, the operation of the central apparatus 1 will be described with reference to FIGS. 12 and 13 are schematic flowcharts showing a main routine of the central apparatus 1, and FIGS. 14 to 15 are schematic flowcharts showing interrupt processing of the central apparatus 1. FIG.

  When the central apparatus 1 starts operating, first, as shown in FIG. 12, the central apparatus 1 first transmits the initial signal control parameters (cycle length, split, offset) to the terminal apparatuses 11 to 13, respectively (step S61).

  Next, the central device 1 sets a count value n in an internal memory (not shown) to 0 (step S62). This count value n is a count value of the number of times of reception of the last floor start timing signal from the terminal device 11.

  Next, the central device 1 determines whether or not the last floor start timing signal has been received from the terminal device 11 (step S63). If not received, it waits until it is received, and if received, the process proceeds to step S64.

  In step S64, the central device 1 holds the current elapsed time t of the built-in timer (t) that measures the elapsed time t.

  Thereafter, the central device 1 starts after resetting the timer (t) to t = 0 (step S65).

  Next, the central device 1 transmits the sensing information request to the terminal device 11 (step S66).

  Next, the central device 1 determines whether or not the vehicle detection count values A1 to A4 and the detected vehicle number count values B1 to B4 as detection information are received from the terminal device 11 (step S67). If not received, it waits until it is received, and if received, the process proceeds to step S68.

  In step S68, the central device 1 stores the vehicle detection count values A1 to A4 and the detected vehicle number count values B1 to B4 received from the terminal device 11 in the internal memory. At this time, the central device 1 causes the previously received count values A1 to A4 and B1 to B4 to remain in the internal memory in addition to the count values A1 to A4 and B1 to B4 received this time.

  Thereafter, the central device 1 increments the count value n by 1 (step S69). Next, the central device 1 determines whether or not the count value n is 2 or more (step S70). If the count value n is 1 (that is, if the number of times of reception of the final floor start timing signal from the terminal device 11 is 1), the process returns to step S63. On the other hand, if the count value n is 2 or more (that is, if the number of times the last stage start timing signal is received from the terminal device 11 is 2 or more), the process proceeds to step S71.

  In step S71, the central apparatus 1 sets the cycle shift synchronization collection information ΔA1 to ΔA4 and ΔB1 to ΔB4 as follows: ΔAm = current vehicle detection count value Am−previous vehicle detection count count value Am, ΔBm = current detection vehicle number The count value Bm is obtained by the previous sensed vehicle number count value Bm. However, m is an integer from 1 to 4. Since the count values A1 to A4 and B1 to B4 are cumulative values as described above, the cycle shift synchronization collection information ΔA1 to ΔA4 is obtained from the start of the last deck in the previous cycle to the start of the last deck in the current cycle. The cycle shift synchronous collection information ΔB1 to ΔB4 from the start of the last deck in the previous cycle to the start of the last deck in the current cycle is shown. The number of vehicles detected by the corresponding vehicle detectors g1 to g4 during the period is shown. In the present embodiment, the cycle shift synchronization collection information ΔA1 to ΔA4, ΔB1 to ΔB4 is the traffic situation information of the inflow paths r1 to r4 in the period, and is one of the traffic situation information related to the control area in the period. Has become a department.

  Next, based on the cycle shift synchronization collection information ΔA1 to ΔA4 and ΔB1 to ΔB4 obtained in step S71, the central device 1 determines the traffic volumes Q1 to Q4 and the occupation ratios D1 to D4 as Qm = ΔBm / t, Dm = Calculated by ΔAm / 20t (step S72). Here, m is an integer from 1 to 4. The traffic volume Q1 is the traffic volume of the inflow path r1 during the period from the start of the last deck in the previous cycle to the start of the last deck in the current cycle. The occupation ratio D1 is an occupation ratio of the inflow channel r1 in the period. Similarly, the traffic volumes Q2 to Q4 are the traffic volumes of the inflow paths r2 to r4 during the period, and the occupation rates D2 to D4 are the occupation ratios of the inflow paths r2 to r4 during the period. Here, t is the elapsed time t (that is, the length of the period from the start of the last deck in the previous cycle to the start of the last deck in the current cycle) that was lastly stored in step S64.

  Subsequently, the central device 1 calculates the cycle length C1 of the important intersection CR1, the split P1, and the traffic state quantities K1 and K2 of each road from the traffic volumes Q1 to Q4 and the occupation ratios D1 to D4 obtained in step S73 ( Step S73). In the present embodiment, the cycle length C1 of the intersection CR1 is also used as the cycle length of the intersections CR2 and CR3 and is a common cycle length.

  As a method for calculating the cycle length C1, the split P1 and the traffic state quantities K1 and K2 of the intersection CR1 from the traffic volumes Q1 to Q4 and the occupation ratios D1 to D4, various known methods and other various methods may be adopted. it can.

  The cycle length C1 of the intersection CR1 can be calculated according to the following equations 1 to 3, for example.

  In Equation 1, L is a loss time (seconds) and is a constant given in advance. In Equations 1 and 2, ρ is a load factor. In Equation 3, m is an integer from 1 to 4, and four expressions are shown as a representative. In Equation 3, Em is the number of queues in the inflow path rm, and Sm is the saturated traffic flow rate in the inflow path rm. The saturated traffic flow rate Sm is a constant given in advance.

  The number of queues Em is calculated as follows.

  First, the vehicle speed Vm of the inflow path rm is calculated by the following formula 4. In Equation 4, F is the average vehicle length (average length of the vehicle), Gm is the diameter of the sensing area of the vehicle detector gm, t is the elapsed time t that was most recently held in step S64 (that is, the last in the previous cycle) The length of the period from the start of the floor to the start of the last floor in the current cycle). For example, when an ultrasonic Doppler speed sensor, a radar type vehicle sensor, or the like is used as the vehicle sensor gm, the vehicle speed Vm of the inflow path rm is not directly related to the following equation (4). It can be obtained as a measured value.

  A lookup table indicating the number of queues Em corresponding to the vehicle speed Vm and the occupation rate Dm of the inflow path rm as parameters is stored in advance in the memory of the central device 1, and this lookup table is referred to. By obtaining the number of queues Em corresponding to the vehicle speed Vm calculated by Equation 4 and the occupation rate Dm obtained in step S72, the number of queues Em can be calculated. This is based on the fact that when the vehicle speed Vm is equal to or less than a predetermined value, the greater the occupation ratio Dm, the higher the degree of congestion and the greater the number of queues Em.

  Further, the split P1 of the intersection CR1 can be calculated by the following equation 5 in accordance with, for example, a so-called load factor ratio distribution method. In Equation 5, the load factor ρ is expressed by Equation 2.

  Further, the traffic state quantities K1 and K2 of each road at the intersection CR1 are calculated by the following equations 6 and 7, for example. In Equations 6 and 7, α and β are constants.

  After step S73, the central device 1 sends to the terminal device 11 signal control parameters (cycle length C1 and split P1 obtained in step S73, and offset O1 of the intersection CR1 obtained most recently in step S89 described later). Is transmitted (step S74). Thereafter, the process returns to step S63. In the initial state, when the offset O1 has not yet been obtained in step S89 at the time of step S74, the central apparatus 1 transmits an initial value as the offset O1 in step S74.

  The processing shown in FIGS. 12 and 13 described above is the main routine of the central apparatus 1.

  The central device 1 performs interrupt processing shown in FIGS. 14 and 15 during processing of this main routine. This interruption process is performed every unit time T2 (for example, 2.5 minutes).

  When starting the interrupt processing shown in FIGS. 14 and 15, the central device 1 first sets the count value n ′ in the internal memory to 0 (step S81). The count value n ′ is a count value of the number of times of reception of the sensing information A5, A6, B5, and B6 from the terminal devices 12 and 13.

  Next, the central device 1 transmits a sensing information request to each of the terminal devices 12 and 13 (step S82).

  Next, the central device 1 determines whether or not the vehicle detection count values A5 and A6 and the detected vehicle number count values B5 and B6 as detection information have been received from the terminal devices 12 and 13 (step S83). If not received, it waits until it is received, and if received, the process proceeds to step S84.

  In step S84, the central device 1 stores the vehicle detection count values A5 and A6 and the detected vehicle count values B5 and B6 received from the terminal devices 12 and 13 in the internal memory. At this time, the central device 1 causes the previously received count values A5, A6, B5, and B6 to remain in the internal memory in addition to the count values A5, A6, B5, and B6 received this time.

  Thereafter, the central device 1 increments the count value n ′ by 1 (step S85). Next, the central device 1 determines whether or not the count value n ′ is 2 or more (step S86). If the count value n 'is 1 (that is, if the number of receptions of the sensing information A5, A6, B5, and B6 from the terminal devices 12 and 13 is 1), the interrupt process is terminated. On the other hand, if the count value n ′ is 2 or more (that is, if the number of receptions of the sensing information A5, A6, B5, and B6 from the terminal devices 12 and 13 is 2 or more), the process proceeds to step S87.

  In step S87, the central device 1 collects the collected information ΔA5, ΔA6, ΔB5, ΔB6 for each unit time T2, ΔAm = current vehicle detection count value Am—previous vehicle detection count count value Am, ΔBm = current detection. Vehicle number count value Bm-obtained by the previous sensed vehicle number count value Bm. Here, m is an integer from 5 to 6. Since the count values A5, A6, B5, and B6 are cumulative values as described above, the collected information ΔA5 and ΔA6 for each unit time T2 is the corresponding vehicle detector for the period from the time point before the unit time T2 to the present time. The number of times of vehicle detection by g5 and g6 is shown. Collected information ΔB5 and ΔB6 for each unit time T2 indicate the number of vehicles detected by the corresponding vehicle detectors g5 and g6 during the period from the time point before unit time T2 to the present time. In the present embodiment, the collection information ΔA5, ΔA6, ΔB5, ΔB6 for each unit time T2 is the traffic situation information of the upstream and downstream inflow paths r5, r6 with respect to the control area during the period, and is related to the control area. It is part of the traffic situation information.

  Next, based on the collected information ΔA5, ΔA6, ΔB5, ΔB6 for each unit time T2 obtained in step S87, the central device 1 sets the traffic volumes Q5, Q6 and the occupation rates D5, D6 as Qm = ΔBm / T2, Calculated by Dm = ΔAm / 20T2 (step S88). Here, m is an integer from 5 to 6. The traffic volume Q5 is the traffic volume of the inflow path r5 during the unit time T2. The occupation ratio D5 is an occupation ratio of the inflow channel r5 during the period. Similarly, the traffic volume Q6 is the traffic volume of the inflow path r6 in the period, and the occupation rate D6 is the occupation ratio of the inflow path r6 in the period.

  Subsequently, the central device 1 calculates the offsets O1 to O3 of the intersections CR1 to CR3 based on the traffic volumes Q5 and Q6 and the occupation rates D5 and D6 obtained in step S88 (step S89).

  As the calculation method of the offsets O1 to O3, various known methods and other various methods can be employed.

  The offsets O1 to O3 of the intersections CR1 to CR3 are, for example, the so-called offset-offset using the cycle length C1 obtained in step S73 in addition to the traffic volumes Q5 and Q6 and the occupation rates D5 and D6 obtained in step S88. It can be determined according to the pattern selection method.

  In this case, the traffic state quantities K5 and K6 of the upstream and downstream inflow paths r5 and r6 are calculated by the following equations 8 and 9. In Equations 8 and 9, α ′ and β ′ are constants.

  A lookup table indicating the offsets O1 to O3 of the intersections CR1 to CR3 corresponding to the traffic state quantities K5 and K6 and the cycle length C1 as parameters is stored in advance in the memory of the central device 1, and this lookup table is stored in the memory. With reference to the traffic state quantities K5 and K6 calculated by Equations 8 and 9, and waiting for the offsets O1 to O3 of the intersections CR1 to CR3 corresponding to the cycle length C1 obtained at the latest in Step S72, the intersection is obtained. The offsets O1 to O3 of CR1 to CR3 can be calculated.

  Thereafter, the central device 1 calculates the splits P2 and P3 of the intersections CR2 and CR3 (step S90). As a method for calculating the splits P2 and P3 of the intersections CR2 and CR3, various known methods and other various methods can be employed.

  The split P2 at the intersection CR2 can be obtained, for example, according to a so-called split pattern selection method by regarding the traffic state quantities K1 and K2 at the intersection CR1 as the respective traffic state quantities at the intersection CR2.

  In this case, a look-up table indicating the split P2 of the intersection CR2 corresponding to the traffic state quantities K1 and K2 as parameters is stored in advance in the memory of the central device 1, and the steps are referred to by referring to this look-up table. By obtaining the split P2 of the intersection CR2 corresponding to the traffic state quantities K1 and K2 obtained the latest in S73, the split P2 of the intersection CR2 can be calculated.

  Similarly, a lookup table indicating the split P3 of the intersection CR3 corresponding to the traffic state quantities K1 and K2 as parameters is stored in advance in the memory of the central device 1, and the steps are referred to by referring to this lookup table. The split P2 of the intersection CR2 can be calculated by obtaining the split P3 of the intersection CR3 corresponding to the traffic state quantities K1 and K2 obtained most recently in S73.

  After step S90, the central device 1 sends to the terminal device 12 the signal control parameters (cycle length C1 most recently obtained in step S73, split P2 of the intersection CR2 obtained in step S90, and step S89). Is transmitted (offset O2 of the intersection CR2) (step S91).

  Subsequently, the central device 1 sends to the terminal device 13 signal control parameters (the cycle length C1 most recently obtained in step S73, the split P3 of the intersection CR3 obtained in step S90, and the intersection obtained in step S89. CR3 offset O3) is transmitted (step S91).

  Thereafter, the interrupt process shown in FIGS. 14 and 15 is terminated, and the process returns to the main routine shown in FIGS.

  As can be seen from the above description of the operation, in the present embodiment, (i) traffic condition information used to obtain the cycle length C1 and split P1 of the important intersection CR1 (traffic conditions of the inflow paths r1 to r4 of the important intersection CR1) Information collection period of information ΔA1 to ΔA4, ΔB1 to ΔB4), which is information, and (ii) a process for allowing the information ΔA1 to ΔA4 and ΔB1 to ΔB4 of this information collection period to be reflected in a later cycle (in step S4) A process (transmission processing information processing period) of the last floor start timing signal to the central device 1 → a series of processes from step S63 to S66 → step S21 → step S67 to S74 → step S22; and (iii) information The relationship between the collection period information ΔA1 to ΔA4 and the cycle in which ΔB1 to ΔB4 is reflected is as shown in FIG. In the present embodiment, as shown in FIG. 16, the collected information processing period is shorter than the period of the last floor (10th floor). FIG. 16 is a time chart schematically showing the relationship between the information collection period, the collected information processing period, and the cycle related to the cycle length C1 and the split P1 of the important intersection CR1.

  As can be understood from FIG. 16, in the present embodiment, regarding the cycle length C1 and split P1 of the important intersection CR1, the information ΔA1 to ΔA4 and ΔB1 to ΔB4 of each information collection period are changed from the end of the information collection period. This is reflected in the cycle starting after the 10th floor period. Therefore, according to the present embodiment, newer traffic condition information can be reflected in the control of each cycle with respect to the cycle length C1 and the split P1 of the important intersection CR1 than in the conventional traffic signal control device. Therefore, according to the first aspect, it is possible to realize traffic signal control that more quickly follows a sudden change in traffic conditions, and further reduces the occurrence of traffic jams and wasteful green time. be able to. In addition, according to the present embodiment, the information collection period is a period from the start of the 10th floor of the cycle to the start of the 10th floor of the next cycle. Similarly, it is possible to reduce the influence of traffic flow fluctuation errors due to changes in signal lamp color.

  Here, the comparative example compared with this Embodiment is demonstrated. This comparative example is a modification of the present embodiment so as to conform to the conventional traffic signal control device.

  That is, in this comparative example, the terminal device 11 transmits the final deck end timing signal to the central device 1 after step S4 instead of transmitting the final deck start timing signal to the central device 1 in the middle of step S4. In step S63, the central device 1 determines reception of the final deck end timing signal instead of the final deck start timing signal. About another point, this comparative example is also the same as this Embodiment.

  In this comparative example, (i) traffic situation information used to obtain the cycle length C1 and split P1 of the important intersection CR1 (information ΔA1 to ΔA4, ΔB1 that are the traffic situation information of the inflow paths r1 to r4 of the important intersection CR1) (B4) information collection period, and (ii) a process for reflecting the information ΔA1 to ΔA4 and ΔB1 to ΔB4 of this information collection period in a later cycle (the central device 1 of the final deck end timing signal in step S4) Transmission process → steps S63 to S66 → step S21 → steps S67 to S74 → step S22) (collection information processing period) and (iii) information collection period information ΔA1 to ΔA4 and ΔB1 The relationship between the cycle in which ΔB4 is reflected is as shown in FIG.

  As can be understood from FIG. 17, in this comparative example, the information ΔA1 to ΔA4 and ΔB1 to ΔB4 in each information collection period are two from the end of the information collection period with respect to the cycle length C1 and the split P1 of the important intersection CR1. This is reflected in the eye cycle. This is because the cycle immediately after the information collection period has already started at the end of the collected information processing period immediately after the information collection period.

  Compared with FIG. 16 and FIG. 17, according to the present embodiment, it can be seen that newer traffic situation information can be reflected in the control of each cycle as compared with the comparative example.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

  For example, although the present embodiment is an example in which the present invention is applied to system control, the present invention may be applied to point control. In this case, for example, the present embodiment may be modified as follows. That is, when the traffic signals subject to point control are traffic lights a1, a2, b1, b2 set at the intersection CR1, the terminal devices 12, 13 are removed, and the functions of the central device 1 are combined with the terminal device 11, What is necessary is just to remove the function regarding the terminal devices 12 and 13 and the function regarding an offset.

  The means for obtaining traffic condition information is not limited to an ultrasonic vehicle sensor or the like, and for example, an imaging means and an image processing means for processing the image may be used.

  Furthermore, although the said embodiment was an example of the road of 1 lane on the one side which crosses, this invention is applicable also when both or one of the roads which cross | intersect is a road of one side multiple lanes. .

1 is a schematic block diagram showing a traffic signal system according to a first embodiment of the present invention. It is a schematic plan view which shows typically arrangement | positioning of the traffic signal etc. in the intersection in the control area of the traffic signal system shown in FIG. It is a time chart which shows the lighting state for 1 cycle of the traffic signal of the important intersection in FIG. It is a schematic flowchart which shows the main routine of the terminal device for important intersections in FIG. It is a schematic flowchart which shows the interruption process of the terminal device for important intersections in FIG. It is a schematic flowchart which shows the other interruption process of the terminal device for important intersections in FIG. It is a schematic flowchart which shows the further interruption process of the terminal device for important intersections in FIG. It is a schematic flowchart which shows the main routine of the terminal device for other intersections in FIG. It is a schematic flowchart which shows the interruption process of the terminal device for said other intersections in FIG. It is a schematic flowchart which shows the other interruption process of the terminal device for said other intersections in FIG. It is a schematic flowchart which shows the further another interruption process of the terminal device for said other intersections in FIG. It is a schematic flowchart which shows the main routine of the central apparatus in FIG. FIG. 13 is a schematic flowchart following FIG. 12. It is a schematic flowchart which shows the interruption process of the central apparatus in FIG. It is the schematic flowchart following FIG. It is a time chart which shows typically the relation between the cycle length of an important intersection, the information collection period relevant to a split, the collection information processing period, and a cycle in this embodiment. It is a time chart which shows typically the relation between the information collection period, collection information processing period, and cycle relevant to the cycle length and split of an important intersection in a comparative example.

Explanation of symbols

1 Central device 11, 12, 13 Terminal device 100-103 Road a1, a2, b1, b2, c1, c2 Traffic light d1, d2, e1, e2, f1, f2 Traffic light r1-r6 Inflow channel CR1-CR3 Intersection g1-g6 Vehicle detector

Claims (7)

A traffic signal control device for controlling a traffic signal installed at a road intersection,
Traffic situation information obtaining means for obtaining traffic situation information related to the road intersection;
Based on the traffic situation information obtained by the traffic situation information obtaining means, signal control parameter obtaining means for obtaining a signal control parameter value;
Means for controlling the traffic signal according to the value of the signal control parameter obtained by the signal control parameter obtaining means;
With
The signal control parameter acquisition means, for a predetermined type of parameters of the signal control parameter, sets each value of the predetermined type of parameter to be reflected in each cycle of the traffic signal cycle two cycles before the cycle. A traffic signal control device, which is obtained based on the traffic condition information in a period between an intermediate predetermined timing in the period and an intermediate predetermined timing in a cycle immediately preceding the cycle.   The traffic signal control device according to claim 1, wherein the traffic status information is traffic status information of each inflow path to the intersection. A traffic signal control device that performs system control for traffic signals installed at each of a plurality of road intersections in a control area,
Traffic situation information obtaining means for obtaining traffic situation information related to the control area;
Based on the traffic situation information obtained by the traffic situation information obtaining means, signal control parameter obtaining means for obtaining the value of the signal control parameter of each road intersection;
Means for controlling the traffic signal at each road intersection according to the value of the signal control parameter obtained by the signal control parameter acquisition means;
With
The signal control parameter acquisition means is configured to reflect the predetermined type of parameter to be reflected in each cycle of the traffic signal at the predetermined intersection with respect to the predetermined type of signal control parameter at the predetermined intersection among the plurality of road intersections. Each value of is based on the predetermined information in the traffic condition information during a period between the intermediate predetermined timing in the cycle two cycles before the cycle and the intermediate predetermined timing in the cycle immediately preceding the cycle. A traffic signal control device characterized by the above.   The traffic signal control apparatus according to claim 3, wherein the predetermined information is traffic state information of each inflow path to the predetermined intersection.   5. The traffic signal control apparatus according to claim 1, wherein the predetermined types of parameters are cycle length and split.   The traffic signal control device according to claim 1, wherein the intermediate predetermined timing is a start time of a last step of the cycle.   A traffic signal system comprising the traffic signal control device according to any one of claims 1 to 6 and the traffic signal device.

Images