TWI406197B - Controlling method for traffic signal system - Google Patents

Abstract

A controlling method for traffic signal system comprises: detecting the traffic flow of each entering road of an intersection for a processor to estimate the waiting length of cars on each entering road. In this way, to determine whether any one of the estimated waiting lengths of the roads allowed for passing through the intersection is larger than a limit length, or any one of the estimated waiting lengths of the roads prohibited from passing through the intersection is zero or larger than the limit length. Furthermore, the processor can also calculate the delayed time of each car on the roads for a plurality of schemes, so as to determine whether a switching of the traffic signal system or a time delay for switching is necessary.

Description

Traffic number control method

The invention relates to a control method of a traffic sign, in particular to a multi-temporal instant multi-level traffic sign control method.

At present, in order to solve the problem of traffic congestion at various intersections, it is generally necessary to control the traffic flow of the traffic intersections by controlling the action time of the intersection traffic signs. For example, the control method of the traffic signal is generally based on the "timing control strategy" to control the timing of the traffic signs (such as the common TOD or DOW control methods); however, the use of "timing control strategy" Knowing the control method of traffic signs, the change of traffic number time system is too rigid, and it is still unable to quickly reflect the instantaneous changes of traffic flow.

Another method of controlling the traffic signs is known as the invention patent case of the Republic of China Public No. 200929100 "Timeline Control Method for Traffic Signs". It uses the extension theory to establish the extension material element model of each traffic flow category, and calculates the correlation degree of each traffic flow category by calculating the obtained traffic flow data, so as to judge the traffic flow category to which the traffic flow data to be tested belongs. Then, according to the judgment result, the time of the traffic signal of the traffic signal is changed.

The above-mentioned other conventional traffic control method can use the extension method to determine the traffic flow in order to control the timing of the traffic signal; however, since the other conventional traffic control method must set several types of vehicles The traffic class, and then establish the extension matter model corresponding to various traffic types, so the calculation and analysis and judgment are quite complicated to use; further, the other control method of the traffic signal can only be based on traffic flow. Judgment is prone to the shortcomings such as the inability to quickly respond to the instantaneous changes in traffic flow, the low accuracy of traffic prediction, and the lack of performance of the log-making system.

The object of the present invention is to improve the above disadvantages to provide a control method for a traffic sign that can quickly respond to instantaneous changes in traffic flow.

Another object of the present invention is to provide a method for controlling traffic signs with better traffic prediction accuracy.

Another object of the present invention is to provide a method for controlling traffic signs that can improve the operational performance of the number.

According to the control method of the traffic sign of the present invention, the method includes the following steps: Step (a), detecting, by a plurality of detectors, vehicles entering and leaving the adjacent road sections of each road for calculation by a central processing unit The estimated length of the waiting team in each adjacent section; the step (b) determines whether the estimated length of the current phase is greater than the critical length, and if it is judged to be 〞, the step (c) is judged. If yes, proceed to step (g); step (c) to determine whether the length of the competitive phase is equal to zero, and if it is judged to be no, proceed to step (d), if it is determined to be 〞, Step (g) is performed; step (d) determines whether the length of the estimated phase of the competition phase is greater than the critical length, and if it is determined to be no, the step (e) is performed, and if it is determined to be 〞, the step is performed. (f); In step (e), a traffic sign switching scheme of a control group (single or multiple intersections) and a plurality of traffic sign extension schemes are preset, and the control group of each scheme is calculated by the central processing unit pushing estimation Waiting for the delay, and then selecting the scheme in which the delay is minimal, and the step (f), by the central processing unit, switching the traffic sign of the competitive phase to the transit state; and step (g), by The central processing unit extends the transit time of the traffic signals of the current phase.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Referring to FIG. 1, a traffic signal control method according to a preferred embodiment of the present invention pre-archives a traffic signal control system 1 for performing related steps by the traffic signal control system 1. The traffic control system 1 includes a central processing unit 11, a database 12, a plurality of traffic signals 13, and a plurality of detectors 14.

The central processing unit 11 is associated with the database 12 for performing the relevant steps of the control method of the traffic log of the present invention.

The database 12 can be used to store data, for example, the central processing unit 11 calculates the data required for the judgment, the traffic volume of the previously recorded intersections, or the history data related to the traffic congestion state.

The plurality of traffic signals 13 can be electrically coupled to the central processing unit 11 by wire or wirelessly, and the traffic signals 13 can be set on each road. The intersection location is such that the central processing unit 11 can switch the light signal action of the traffic signal 13 and control the signal extension time of the traffic signal 13 and the like.

The detector 14 can be electrically coupled to the central processing unit 11 by wire or wirelessly. As shown in FIG. 2, each of the detectors 14 can be disposed on each road to detect the detection. Each of the vehicles 15 of the device 14 has various information such as vehicle speed, vehicle occupancy, time to enter or leave the detector detection range, etc.; the detector 14 preferably utilizes infrared light or Detection by means of the Global Positioning System (GPS), etc., thereby enabling the traffic control system 1 to instantly estimate the actual number of vehicles, and how to calculate various information obtained by each vehicle 15 to calculate Estimating the actual number of vehicles in the system is familiar to those skilled in the art and will not be described here.

In order to clearly disclose the technical content of the control method of the traffic signal of the present invention, the following related terms are defined in conjunction with the embodiment disclosed in FIG. 2, which discloses a first lateral road 21, a second lateral road 22, and a The first longitudinal road 23 and a second longitudinal road 24. The intersection of the first lateral road 21, the second lateral road 22, the first longitudinal road 23 and the second longitudinal road 24 may constitute an intersection; in addition, the traffic signals 13 of the traffic signal control system 1 described above are respectively It is disposed at each intersection as shown in the figure, and each detector 14 can be respectively disposed at each road surrounding location as shown in the figure, wherein:

The term "phase" as used in the present invention means that the traffic sign type formed by the traffic flow through the intersection along the first lateral road 21 and the second lateral road 22 is referred to as a "phase"; The traffic semaphore type formed along the linear direction of the first longitudinal road 23 and the second longitudinal road 24 is also referred to as a "phase"; therefore, the second diagram of the present invention discloses a 〝 The simple two-phase embodiment, and the simple two-phase embodiment are convenient for exemplifying the steps of the control method of the traffic sign of the present invention, and the control method of the traffic sign of the present invention is more applicable to other The control of the traffic sign of the phase is not limited to the control of the traffic sign that can only be applied to the simple two-phase.

The "complete cycle" as used in the present invention refers to the time taken by the traffic signal 13 to change from the green light start state to the next green light start state in a time-phase phase; for example, Assume that the switching process of the traffic sign 13 is green light start → yellow light → red light → green light starts to light, then the full cycle is the time when the green light start quantity is switched to the next green light start light.

The "current phase" as used in the present invention refers to a state in which a phase is currently traversable; for example, assuming a straight line along the first lateral road 21 and the second lateral road 22 In the green light state, one of the first lateral roads 21 and the second horizontal road 22 is the current phase.

The term "competitive phase" as used in the present invention refers to a state in which a phase is currently unreachable; for example, assuming a straight line along the first longitudinal road 23 and the second longitudinal road 24 In the red light state, the time period formed by the first longitudinal road 23 and the second longitudinal road 24 is the competition phase.

The "adjacent section" as used in the present invention refers to the area of the traffic number 13 to the detector 14 disposed at the intersection of a road (as shown in FIG. 2); for example, as the second The area between the traffic number 13 of the first lateral road 21 and the detector 14 shown in the figure is the adjacent road section; further, the distance between the traffic signal 13 and the detector 14 is preferably 100. Meters to 250 meters, but still need to adjust the distance from the control intersection to the upstream intersection.

The "waiting fleet" as used in the present invention refers to the number of estimated vehicles of the vehicle 15 that are stopped in the adjacent road section, and the estimated number of vehicles is determined by the traffic signal control system 1 according to the detector 14. The results are estimated.

The "waiting fleet length" as used in the present invention refers to the estimated length of the waiting team in the adjacent road section, and the length of the waiting fleet is determined by the traffic signal control system 1 according to the detector 14. The results are estimated.

The "critical length" of the present invention is used to determine whether the length of the current waiting fleet is too long; for example, when the length of the waiting fleet in a phase is greater than the critical length, it represents the time phase, etc. If the length of the waiting team has exceeded the critical value, it is better to immediately propose an evacuation strategy; otherwise, it means that the length of the waiting team in the phase has not exceeded the critical value; in addition, the critical length is set by the actual traffic demand or historical experience rules.

The term "stop lag" as used in the present invention refers to the lag time of all vehicles in each adjacent road section in a "complete cycle".

Referring to Figures 1 and 3, the control method of the traffic number executed by the traffic control system 1 of the present invention includes the following steps, wherein:

In step S31, the traffic signal control system 1 is activated to continuously detect the actual number of vehicles of the vehicle 15 entering and exiting the "adjacent section" of each road by the plurality of detectors 14; thereby, according to the detection As a result of the detection by the device 14, the central processing unit 11 can calculate the "estimated waiting length" of the "waiting fleet" in each "adjacent section". More specifically, as shown in FIG. 4, it is revealed that the time phase formed along the linear direction of the first lateral road 21 and the second lateral road 22 is the "current phase", and along the first longitudinal direction. The time phase formed by the straight line direction of the road 23 and the second longitudinal road 24 is "competitive phase". In this case, it is assumed that the "estimated waiting length" of the first lateral road 21 is Q _a and the second The "estimated waiting length" of the horizontal road 22 is Q _b , the "estimated waiting length" of the first longitudinal road 23 is Q _c and the "estimated waiting length" of the second longitudinal road 24 is Q _d . In addition, the traffic signal control system 22 further, the first 23 and the second transverse lateral road road 24 also for 21 minutes, a second longitudinal path in advance of the other first longitudinal road "critical length" is set corresponding to the L _a , L _b , L _c , L _d (the value of which is set by the user according to actual needs).

In step S32, the central processing unit 11 determines whether the "estimated waiting length" of the current "current phase" is greater than the "critical length". If the determination is negative, the process proceeds to step S33, and if it is determined to be 〞, Step S37; more specifically, as shown in Fig. 4, revealing Q _a >L _a and Q _b >L _b of "current phase", at this time, it means "the current phase""The estimated length of the waiting team" has exceeded the critical standard value (in fact, only one of Q _a >L _a or Q _b >L _{b is} required to meet the conditions), therefore, the subsequent better must choose to extend The transit time of the "current phase" (ie, the extension of the green time) to solve the traffic congestion problem; conversely, as shown in Figure 5, the Q _a <L _a and Q _b <L _{b of the} "current phase" are revealed. At this time, the "estimated waiting length" of the "waiting fleet" representing the "current phase" has not exceeded the critical standard value (in fact, only one of Q _a <L _a or Q _b <L _{b is required} ) Eligible to the condition), therefore, make subsequent decisions to determine whether to switch the current "competitive phase" to the pass state ( Switch to green).

In step S33, the central processing unit 11 determines whether the "estimation waiting length" of the current "competition phase" is equal to zero. If the determination is no, the process proceeds to step S34. If the determination is yes, the process proceeds to step S37. More specifically, as shown in Figure 6, it is revealed that Q _c =0 and Q _d =0 of the “competitive phase”. At this time, the system represents “competition phase” and there is no “waiting for the team”. At this stage, there is still no urgency to switch the "competitive phase" to the traffic state. It is better to continue to extend the transit time of the "current phase" (ie, extend the green time) in order to solve the traffic congestion problem; As shown in Figure 7, the Q _C ≠ 0 and Q _d ≠ 0 of the "competitive phase" are revealed. At this time, the fact that the "competition phase" has "waiting for the team" (in fact, only Q is required) _c ≠0 or one of Q _d ≠0 can be qualified. Therefore, it is still necessary to make a decision to determine whether to switch the current “competition phase” to the traffic state (ie, switch to the green light).

In step S34, the central processing unit 11 determines whether the "estimated waiting length" of the current "competitive phase" is greater than the "critical length". If the determination is negative, the process proceeds to step S35, and if it is determined to be 〞, Step S36 is performed; more specifically, as shown in Fig. 8, it is revealed that Q _c > L _c and Q _d > L _d of "competitive phase", and at this time, it means "competition phase""The estimated length of the waiting team" has exceeded the critical standard value (in fact, only one of Q _c > L _c or Q _d > L _{d is} eligible), so the subsequent better must be immediately "Competitive phase" switches to a passable state (ie, switches to a green light) to resolve the traffic congestion problem of the "competitive fleet" of the "competitive phase"; conversely, as shown in Figure 9, the "competition phase" is revealed Q _c <L _c and Q _d <L _d , at this time, the “estimated waiting length” of the “waiting team” representing the “competition phase” has not exceeded the critical standard value (in fact, only Q is required) _c <L _c or Q _d <L _d wherein one can meet the conditions), and therefore, a subsequent decision may proceed to determine whether the current Phase "switch when competition is passable state (ie switched to green), or still consider extending the" passage of time with "the time of the current (ie, extend the green time).

In step S35, the database 12 is preset with a traffic sign switching scheme of a control group (single or multiple intersections) and a plurality of traffic sign extension schemes. The traffic log switching scheme of the embodiment may be set to VTTD (0), and the execution content of the VTTD (0) scheme is to immediately switch the current "competitive phase" to the transit state; in addition, each of the traffic signs is extended. The scheme can be divided into VTTD (1), VTTD (2), ... VTTD (n) and other schemes, VTTD (1), VTTD (2), ... VTTD (n) schemes The execution content is the number of extended transit times for the "current phase"; for example, VTTD(1) can extend the "current phase" transit time by 2 seconds, and VTTD(2) can extend the " The current time phase is 4 seconds, ..., etc., and so on. In addition, the step S35 is that the central processing unit 11 can estimate the cost of the traffic sign switching scheme and the traffic sign extension scheme according to the historical data and relevant experience rules stored in the database 12, that is, Further calculate the control group "stop lag" for each solution, and then choose to execute the scheme with the minimum "stop lag".

More specifically, the calculation method of "stop lag" for each of the above schemes is mainly based on historical data, and then the rule of thumb is used to estimate the "stop lag" that may be generated by each scheme. For example, when calculating the "stop lag" of the VTTD (1) scheme, as shown in Figure 4, it is mainly estimated that when it is decided to extend the transit time of the "current phase" for 2 seconds, the first The sum of the waiting time of the "waiting fleet" to which the longitudinal road 21, the second longitudinal road 22, the first horizontal road 23 and the second horizontal road 24 belong in a "full cycle"; for example: the central processing unit 11 can be judged on the basis of historical data, assuming that the current time of the "current phase" formed by the first longitudinal road 21 and the second longitudinal road 22 is extended to 2 seconds, the "waiting fleet" of the first horizontal road 21 What is the delay waiting time, the waiting time of the "waiting fleet" of the second horizontal road 22, and the waiting time of the "waiting fleet" of the first longitudinal road 23, .... etc., and so on, so that you can get the "stop lag" for each program; in addition, the calculation method can be combined with various intelligent algorithms according to the rule of thumb (such as Neuron-like algorithms, fuzzy algorithms, gene algorithms, etc.) In this capacity is not repeated here.

In step S36, the central processing unit 11 switches the current traffic phase 13 of the "competitive phase" to a passable state.

In step S37, the central processing unit 11 is used to extend the transit time of the traffic sign 13 of the current "current phase"; wherein the length of the extension scheme is an adjustable preset value (for example, 10 seconds, 20 Seconds, 30 seconds, ..., etc.).

The above control method of the traffic sign of the present invention can be performed by the "second-by-second control" method; more specifically, the traffic sign control system 1 can perform the foregoing related steps every second, so as to dynamically grasp the traffic road at any time. The preferred treatment scheme is determined, and the instantaneous change of the traffic flow can be quickly reacted by the present invention.

The control method of the traffic sign of the present invention can be made by determining whether the "estimation length" of the "current phase" and the "competition phase" is greater than the "critical length", such as whether to switch traffic signs or extend the passage. Time and other decisions to achieve rapid response to the transient changes in traffic flow.

The control method of the traffic sign of the present invention can detect the entry and exit situation of each traffic road by means of an instant, and propose corresponding control judgments to achieve the effect of providing better traffic prediction accuracy.

The control method of the traffic sign of the present invention can provide a better solution to solve traffic congestion by calculating the traffic sign switching scheme and the "stop delay" of each traffic sign extension program, so as to improve the traffic sign The effectiveness of operational performance.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1. . . Traffic control system

11. . . Central processing unit

12. . . database

13. . . Traffic number

14. . . Detector

15. . . vehicle

twenty one. . . First lateral road

twenty two. . . Second lateral road

twenty three. . . First longitudinal road

twenty four. . . Second longitudinal road

Figure 1: Schematic diagram of the traffic control system used in the control method of the traffic sign of the present invention.

Fig. 2 is a schematic view showing the application of the traffic control system used in the control method of the traffic sign of the present invention to a simple two-phase intersection.

Figure 3 is a flow chart showing the steps of the control method of the traffic sign of the present invention.

Figure 4: Schematic diagram of traffic flow reference (1) for the control method of the traffic sign of the present invention.

Figure 5: Schematic diagram of traffic flow reference for the control method of the traffic sign of the present invention (2)

Figure 6: Schematic diagram of traffic flow reference for the control method of the traffic sign of the present invention (3)

Figure 7: Schematic diagram of traffic flow reference for the control method of the traffic sign of the present invention (4)

Figure 8: Schematic diagram of traffic flow reference for the control method of the traffic sign of the present invention (5)

Figure 9: Schematic diagram of traffic flow reference for the control method of the traffic sign of the present invention (6)

Claims (5)

A method for controlling traffic signs includes the steps of: (a) detecting, by a plurality of detectors, vehicles entering and exiting adjacent road sections of each road for calculation by a central processing unit to estimate each adjacent road section; (b) Determine whether the length of the estimated time of the current phase is greater than the critical length, and if it is judged as 〝 no, proceed to step (c) if it is determined to be 〞, then proceed (g); (c) judging whether the length of the evaluation of the competition phase is equal to zero, if it is judged as 〝 no, proceed to step (d), and if it is judged to be 〞, proceed to step (g); It is judged whether the length of the estimation of the competition phase is greater than the critical length, and if it is judged as 〝 no, the process proceeds to step (e), and if it is determined that 〝 is 〞, the process proceeds to step (f); (e) presets one Traffic sign switching scheme and several traffic sign extension schemes, and the central processing unit pushes the estimation to calculate the stop delay of each scheme, and then selects the scheme in which the delay is the smallest; (f) The central processing unit switches the traffic sign of the competitive phase to a passable state; and (g) Extend the current travel time traffic signals with the time by the central processing unit. The method for controlling traffic signs according to item 1 of the patent application scope, wherein the method is performed by a second-by-second control method. According to the control method of the traffic number mentioned in item 1 of the patent application scope, the execution content of the traffic sign switching plan is to immediately switch the current competitive phase to the pass state, and the execution of each traffic sign extension plan The content is the number of extended transit times for the current phase. According to the control method of the traffic number mentioned in item 3 of the patent application scope, the calculation method of the traffic sign switching scheme and the stoppage of each traffic sign extension program is estimated by the central processing unit Waiting for each team on a road waits for a full period of delay and sums it up to obtain a delay in each plan. According to the control method of the traffic number mentioned in the first application of the patent scope, the number of actual vehicles of the vehicle entering and exiting the adjacent road section of each road is detected by the plurality of detectors for the central processing unit to push Estimate the waiting length of the waiting team.