CN103280113B - Self-adaptive intersection signal control method - Google Patents

Abstract

The invention belongs to the field of urban traffic control, and provides a self-adaptive intersection signal control method. By installing vehicle monitors to detect the number of vehicles, the lengths of vehicle queues are acquired, and a signal control strategy for the next cycle is determined according to the lengths of vehicle queues at an intersection in the previous cycle. The method utilizes the vehicle detectors already arranged in a city to acquire traffic flow data and calculate the length of the queue of each lane, and the signal timing scheme of the next cycle is dynamically adjusted according to the different proportions of queue lengths. Taking a cycle as a unit, a timing scheme is calculated, the load of calculation is low, and moreover, the method also can achieve the purpose that intersection signals can be self-adaptively controlled according to the density of traffic flow. In addition, the algorithm of the method is simple, and the method has low requirement on hardware and construction quantity, and therefore is convenient to popularize.

Description

A kind of adaptive intersection signal control method

Technical field

The invention belongs to urban traffic control field, be specifically related to a kind of adaptive intersection signal control method.

Background technology

Traffic signalization with crossing microcosmic wagon flow for control object, with phase place and time for yardstick distributes the right of way of vehicle in crossing, be separated from the time wagon flow of conflicting, traffic flow reasonably guided and dispatches, reach minimizing traffic hazard, improve the object of traffic safety and conevying efficiency.

At present, intersection signal control method both domestic and external mainly contains timing controlled, induction controls and adaptive control three class, and timing controlled is suitable for the crossing that the comparatively large and traffic of the volume of traffic is evenly distributed; It is less than normal that induction control is suitable for the volume of traffic, changes uneven crossing, but when the volume of traffic is large, cannot adjusts and optimize signal condition to alleviate traffic congestion according to transport need; Adaptive control is the traffic data sent here according to detecting device, best timing scheme under certain performance index of real-time generation, the signal timing dial parameters such as automatic adjustment split, Cycle Length and the green time difference, the traffic flow of signal timing dial and change is adapted, at present, SCOOT and SCATS is the city traffic signal lamp self-adaptation control method of two kinds of main flows.SCATS system, according to traffic flow situation of change, adjusts signal controling parameters in real time, but possibility limited amount, perform each scheme time long (change in a tens minutes scheme), do not possess feedback function, and before checkout equipment is placed on stop line, cannot vehicle queue length be detected; SCOOT system availability is strong, can adopt continuity inching to timing parameter, but its relevant Controlling model all by mathematical model simulation out, and mathematical model is more complicated, and required simulation time is longer, can produce contradiction between reliability and real-time.In addition, SCOOT and SCATS system all needs to gather mass data, and construction cost is high.

Intersection vehicles queue length is the important indicator characterizing traffic behavior, and current optimum real-time signal control mainly solves based on each import track queue length in crossing.But calculate queue length comparatively complicated, usually rely on multiple detecting device or utilize vedio data, the calculated amount of scan picture is very large, expensive, and is subject to weather effect, and the reliability of system is poor.The equipment such as inductive coil have been laid to obtain the volume of traffic in present most cities, vehicle holding time, road occupancy, the Real-time Traffic Information such as the degree of crowding and queue length, but the transport need of crossing all directions might not balance, the queue length in each import track is also not necessarily equal, particularly when the volume of traffic is larger, when detecting device is taken by certain vehicle commander in queue the time, be unable to estimate the information such as the vehicle number that arrives in real time and queue length, thus cause vehicle queue length computational accuracy not high, signal time distributing conception out of true.If install multiple detecting device on every bar track, not only cause many places to damage to original road surface, and quantities is large, installs inconvenient, the feasibility of engineering and the operability of enforcement lower.

Summary of the invention

For the shortcomings and deficiencies that prior art exists, the object of the invention is to a kind of adaptive intersection signal control method, the method realizes integrative design intersection by the intersection vehicles queue length in upper cycle.

A kind of adaptive intersection signal control method, the method is carried out according to following steps:

Step one, 1 wagon detector is installed in each track, crossing, and the distance of wagon detector and stop line is designated as L, and each wagon detector opens the bright moment for the red light gathering each phase place n-th cycle the green light in the n-th cycle opens the bright moment the red light in the (n+1)th cycle opens the bright moment each vehicle is by holding time t during wagon detector _o, wagon detector free time interval t _fand pass through the vehicle number n of detecting device;

Described phase place comprises the craspedodrome phase place at craspedodrome queue place and the phase place of turning left at queue place of turning left;

One-period extinguishes the moment for opening the bright moment from red light to green light, note G _minfor minimum green time, note g _layfor unit green light extends or the time of shortening, note G _mainfor maximum total green time of major trunk roads;

Step 2, at the end of one-period effective green time, detection data are transferred to back-end data disposal system by wagon detector, analyze the change of traffic behavior in this cycle, find out the transition moment T of wagon detector eigenstate _a, T _band T _c;

T _athe transition between states moment that red light opens that bright rear vehicle v1 starts to take for a long time wagon detector, T _aafter moment, wagon detector is taken for a long time by vehicle v1, moment T _acan be used to determine whether this phase place track exists longer vehicle platoon;

T _bthe transition moment that green light opens that bright rear vehicle v1 sails out of wagon detector, green light open bright after, T _bbefore moment, the vehicle before stop line sails out of crossing with saturation volume rate successively, but is 0 by the vehicle number of detecting device, at T _bafterwards, vehicle is with maximum current flow rate by wagon detector, and the holding time of wagon detector and interval time reduce;

T _cthat in vehicle queue's queue, last car v2, by the transition between states moment of wagon detector, determines last car of queue v ₂according to being: in queue queue, during continuous vehicle passing detection device, interval time is less, when a car and its Following Car pass through detecting device interval greater than threshold value A, illustrate in Following Car not Queue here queue;

The value obtaining threshold value A according to current traffic survey data statistics is 3s;

Step 3, adopt from moment is to T _aby the vehicle number n of detecting device in time period in moment _lcalculate the vehicle density k under saturated conditions _j, then k _j=n _l/ L; Adopt from moment is to T _bdistance L between time period in moment and stop line to wagon detector calculates the dissipation speed v of vehicle queue's queue, then and then pass through T _band T _cby the vehicle number n of detecting device in time period _jcalculate the maximum queue length Q in this cycle;

(1) if there is not T _amoment, then Q < L;

(2) if there is T _amoment, then determine T further _cmoment;

If there is T in (a) _cmoment, then Q=L+n _j/ k _j;

If there is not T in (b) _cmoment, then red light of lower cycle is opened the bright moment as transition moment T _c, statistics T _bwith by the vehicle number n of detecting device in time period _j, then Q > L+n _j/ k _j;

Step 4, the signal control strategy of adjustment major trunk roads, detailed process is as described below:

Craspedodrome queue length Q is calculated respectively according to the method for step 3 _swith the queue length Q that turns left _l;

(1) if the length of two queues is all less than L, then turn left phase time and craspedodrome phase time all distribute minimum green time, i.e. T _g1=T _g2=G _min;

(2) if only have a certain queue length to be less than L, then the minimum green time T of the phase assignments at this queue place _g1=G _min, the queue that another length is more than or equal to L then needs to determine whether this queue exists transition moment T _c:

If there is transition moment T in (a) _c, then according to T _cwith to calculate in this time interval vehicle by minimum speed v needed for L _m, then have determine whether there is green light Slack Time:

If a) v _m, then there is green light Slack Time in < v, former long green light time is cut unit green light and change time g _lay, i.e. T _g2=T _g2-g _lay;

If b) v _m, then there is not green light Slack Time, namely indicate residual queue in>=v, if T _g2< G _main-T _g1, then g is added at former long green light time _lay, i.e. T _g2=T _g2+ g _layif, T _g2=G _main-T _g1, then T _g2=T _g2;

If there is not transition moment T in (b) _c, then represent at the end of green time, detecting device upstream also has queue queue, then the long green light time of this phase place is T _g2=G _main-T _g1;

(3) if the queue length of two queues is all more than or equal to L, then determine whether individual queue exists transition moment T _c, then have:

If both there is moment T in (a) _c, then determine whether each phase place has green time more than needed, perform green light according to the strategy (a) of step (2) and extend or reduce to obtain long green light time T _g1and T _g2, wherein: T _g1+ T _g2≤ G _main;

If there is moment T in (b) queue _c, there is not moment T in another _c, then there is moment T _cphase place according to the strategy (a) of step (2) perform green light extend or reduce to obtain long green light time T _g1, there is not moment T _cthe green time of phase place be T _g2=G _main-T _g1;

If neither there is transition moment T in (c) _c, then according to Q _sand Q _llength ratio distribute the green time of phase place and craspedodrome phase place of turning left, namely $\left\{\begin{array}{c}{T}_L=G_{\mathrm{main}}\&times;\frac{Q_L}{Q_L+Q_S}\\ T_S=G_{\mathrm{main}}\&times;\frac{Q_S}{Q_L+Q_S}\end{array}\right.$

Wherein: T _lthe long green light time of phase place of turning left, T _sthe long green light time of craspedodrome phase place, Q _scraspedodrome phase alignment length, Q _lphase alignment length of turning left;

Step 5, the signal control strategy of adjustment subsidiary road, detailed process is as described below:

Subsidiary road is kept straight on and is turned left and to be controlled by a phase place, remembers G _minorfor the maximum green time of subsidiary road, G _minfor minimum green time, g _layfor unit green light extends or the time of shortening, first calculate the queue length Q of subsidiary road according to the method for step 3, T _gfor subsidiary road green time;

(1) if queue length Q < is L, then Minimum Green Time T is distributed _g=G _min;

(2) if queue length Q>=L, then transition moment T is determined whether there is _c, then have:

If there is transition moment T in (a) _c, then according to T _cwith to calculate in this time interval vehicle by minimum speed v needed for L _m, then have determine whether there is green light Slack Time:

If a) v _m, then there is green light Slack Time, then T in < v _g=T _g-g _lay;

If b) v _m, then there is not green light Slack Time, namely indicate residual queue in>=v, if T _g< G _minor, then T _g=T _g+ g _layif, T _g=G _minor, then T _g=T _g;

If there is not transition moment T in (b) _c, then T _g=G _minor.

Compared with prior art, beneficial effect is in the present invention:

Method of the present invention utilizes the wagon detector laid in city to obtain traffic flow data, calculates the queue length in each track, according to the signal time distributing conception in next cycle of different proportion dynamic conditioning of queue length.The method carries out the calculating of timing scheme in units of the cycle, and operand is little, and can reach intersection signal realizes adaptive control object according to vehicle density.In addition, the method algorithm is simple, requires lower, do not increase construction cost by existing device to hardware and quantities, convenient popularization.

Accompanying drawing explanation

Fig. 1 is main and secondary road intersection vehicles detector layout schematic diagram.

Fig. 2 is the time dependent schematic diagram of vehicle queue queue on a track.

Transition moment T is there is in Tu3Shi vehicle queue queue evanishment _cand have the time dependent schematic diagram of the queue of green time more than needed.

Transition moment T is there is in Tu4Shi vehicle queue queue evanishment _cbut the time dependent schematic diagram of queue of green time not more than needed.

Transition moment T is there is not in Tu5Shi vehicle queue queue evanishment _cthe time dependent schematic diagram of queue.

Fig. 6 is major trunk roads signal adaptive control flow chart.

Fig. 7 is subsidiary road signal adaptive control flow chart.

Below in conjunction with drawings and Examples, particular content of the present invention is described in more detail.

Embodiment

It should be noted that the dimension of the physical quantity that the present embodiment provides is the unified standard dimension in this area, those skilled in the art are according to physical quantity and its dimension known, and therefore following content provides no longer one by one.

It should be noted that one-period is open the bright moment from red light to extinguish the moment to green light, according to prevailing traffic rule, vehicle during amber light flicker within stop line can not pass through, and therefore in the present invention, the flicker duration of amber light is grouped into inside red light duration in the lump, no longer will consider amber light in following embodiment.

Defer to technique scheme, as shown in Figure 1, it is main and secondary road intersection vehicles detector layout schematic diagram, in figure, east-west direction is major trunk roads, in the craspedodrome road of distance crossing La be provided with wagon detector on turning left, North and South direction is subsidiary road, and in distance, Ls place, crossing is provided with wagon detector.Major trunk roads are provided with turn left phase place and craspedodrome phase place, and subsidiary road is kept straight on and turned left by a phase control.Crossing is provided with signal controller, and all wagon detectors are implemented detect the volume of traffic, detecting device holding time, free time and be transferred to back-end data disposal system.The Real-Time Data Handling System (RTDHS) on backstage dynamically determines the signal time distributing conception in next cycle according to result of calculation, and is transferred to signal controller.

Because major trunk roads are identical with the vehicle queue length computing method of subsidiary road, therefore following proposal controls for an arterial highway, and the distance of detector distance stop line is L.

A time dependent schematic diagram of track queue queue as shown in Figure 2, when red light open bright after, vehicle start stop queue up until when green light opens bright, queue queue start dissipate, go round and begin again like this.When not occurring transition moment T in the red light time period _apoint, illustrates queue length Q < L, otherwise, account for queued queue overflow detecting device.According to to T _athe vehicle number n of the queuing in the time period _lcalculate the vehicle density under saturated conditions:

k _j＝n _L/L

The bright moment is opened from green light to moment T _b, queue rolls crossing away from saturation volume rate, and the dissipation speed of queue is:

$v=L/(T_B-T_G^n)$

There is transition moment T in queue queue's evanishment as shown in Figure 3 _cand have the time dependent schematic diagram of the queue of green time more than needed; There is transition moment T in queue queue's evanishment shown in Fig. 4 _cbut the time dependent schematic diagram of queue of green time not more than needed.According to T _cwith interval calculation if v _m< v, then as Fig. 3 exists green time more than needed; If v _m>=v, then as Fig. 4 does not exist green time more than needed.Utilize T _band T _ccalculated the maximum queue length in this cycle by the vehicle number n of wagon detector in time period:

Q＝L+n/k _j

There is not transition moment T in queue queue's evanishment as shown in Figure 5 _cthe time dependent schematic diagram of queue, moment T _cdo not exist and show that, at the end of effective green time, detector back also has waiting list, now will regard T as _c, statistics T _bwith by the vehicle number n of detecting device in time period _j, then queue length is:

Q＞L+n _j/k _j

Next, determine the parameter in control program, because an intersection signal cycle can not be long or too short, if too short, then each Phase-switching is frequent, and vehicle parking number increases and vehicle is started to walk continually and stopped, if long, the time that then in queue queue, vehicle is waited for is just long, in this programme, therefore establish minimum green time G _min(being generally 15s), unit green light changes time g _lay(3s), maximum total green time G of major trunk roads _main(being generally 80s), the maximum green time G of subsidiary road _minor(being generally 45s).

Be major trunk roads signal adaptive control flow chart as shown in Figure 6, first calculate craspedodrome queue length Q _swith the queue length Q that turns left _l, then carry out signal control according to following steps:

(1) if the length of two queues is all less than L, then phase place of turning left and craspedodrome phase place all distribute minimum green time, i.e. T _g1=T _g2=G _min;

(2) if a certain queue length is less than L, then the minimum green time T of this phase assignments _g1=G _min, and the length of another queue is more than or equal to L, then determine whether this queue exists T _c:

If there is transition moment T in (a) _c, then according to T _cwith the time interval to calculate in this time interval vehicle by minimum speed needed for L determine whether there is green light Slack Time

If a) v _m, there is green light Slack Time and then former long green light time cut unit green light change time g in < v _lay, i.e. T _g2=T _g2-g _lay;

If b) v _m, there is not green light Slack Time and then indicate residual queue, if T in>=v _g2< G _main-T _g1, then add unit green light at former long green light time and change time g _lay, i.e. T _g2=T _g2+ g _layif, T _g2=G _main-T _g1, then T _g2=T _g2;

If there is not transition moment T in (b) _c, then illustrate at the end of green time, detecting device upstream also has queue queue, then the long green light time of this phase place is T _g2=G _main-T _g1;

(3) if the queue length of two queues is all more than or equal to L, then individual queue whether existence transition moment T is determined _c:

If both there is transition moment T in (a) _c, then determine whether each phase place has green time more than needed, perform green light according to the strategy (a) of step (2) and extend or reduction;

If there is transition moment T in (b) _c, one does not exist, then the phase place that there is the transition moment performs green light prolongation according to the strategy (a) of step (2) or reduces to obtain long green light time T _g1, the green time of another phase place is T _g2=G _main-T _g1;

If neither there is transition moment T in (c) _c, then according to Q _sand Q _llength ratio distribute the green time of phase place and craspedodrome phase place of turning left, namely $\left\{\begin{array}{c}{T}_L=G_{\mathrm{main}}\&times;\frac{Q_L}{Q_L+Q_S}\\ T_S=G_{\mathrm{main}}\&times;\frac{Q_S}{Q_L+Q_S}\end{array}\right..$

Wherein: T _lthe long green light time of phase place of turning left, T _sthe long green light time of craspedodrome phase place, Q _scraspedodrome phase alignment length, Q _lphase alignment length of turning left.

Be subsidiary road signal adaptive control flow chart as shown in Figure 7, subsidiary road is kept straight on and is turned left by a phase control, so first calculate the queue length Q of subsidiary road,

(1) if queue length Q < is L, then Minimum Green Time T is distributed _g=G _min;

(2) if queue length Q>=L, then transition moment T is determined whether there is _c, then have:

If there is transition moment T in (a) _c, then according to T _cwith to calculate in this time interval vehicle by minimum speed v needed for L _m, then have determine whether there is green light Slack Time:

If a) v _m, then there is green light Slack Time, then T in < v _g=T _g-g _lay;

If b) v _m, then there is not green light Slack Time, namely indicate residual queue in>=v, if T _g< G _minor, then T _g=T _g+ g _layif, T _g=G _minor, then T _g=T _g;

If there is not transition moment T in (b) _c, then T _g=G _minor.

Below provide specific embodiments of the invention, it should be noted that the present invention is not limited to following specific embodiment, all equivalents done on technical scheme basis all fall into protection scope of the present invention.

Embodiment:

As the cross junction in Fig. 1, arranging east-west direction is major trunk roads, and wagon detector is apart from the distance L of stop line _a=80m, North and South direction is subsidiary road, and wagon detector is apart from the distance L of stop line _b=60m, the maximum total long green light time G of major trunk roads _mainfor 80s, the maximum long green light time G of subsidiary road _minorfor 45s, minimum long green light time G _minfor 15s, unit green light changes duration g _layfor 3s.

The timing state of the signal lamp obtained from 10:00:00 for the present embodiment as shown in table 1.

Suppose the moment for a red light start time of major trunk roads, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as craspedodrome road transition moment point T at the moment _a9:59:10, craspedodrome road transition moment T _b9:59:24, craspedodrome road transition moment T _c9:59:30, craspedodrome green light start time turn left green light start time to T _aby the equivalent vehicle number n of wagon detector in time _l=20, T _bto T _ctime is interior is n by the equivalent vehicle number of wagon detector _j=2, turn left and there is not transition moment T _a, T _b, T _c.Calculate saturation flow density: k _j=n _l/ L _a=20/80=0.25, queue dissipation speed with $v_m=L_a/(T_{G,L}^0-T_C)=80/(44-30)=5.71m/s,$ Due to vm < v, there is green time more than needed, queue length Q _s=L _a+ n _j/ k _j=80+2/0.25=88m, therefore craspedodrome of lower cycle long green light time T _s=T _s-g _lay=30s-3s=27s, long green light time of turning left is T _l=G _min=15s.

And the moment for the red light start time of subsidiary road, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as green light start time at the moment for 10:00:00, long green light time T _gfor 30s, there is not transition moment point T _a, therefore the long green light time in lower cycle is T _g=G _min=15s;

Moment for another red light start time of major trunk roads, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as craspedodrome green light start time at the moment for 10:00:31, there is not transition moment point T _a, turn left red light start time for 10:00:00, turn left transition moment point T _a10:00:47, turn left transition moment T _b10:01:08, turn left transition moment T _c10:01:11, turns left green light start time to T _aby the equivalent vehicle number n of wagon detector in time _l=19, T _bto T _ctime is interior is n by the equivalent vehicle number of wagon detector _j=1.Calculating is turned left track saturation flow density: k _j=n _l/ L _a=19/80=0.23, queue dissipation speed $v=L_a/(T_B-T_{G,L}^1)=80/10=8m/s$ With $v_m=L_a/(T_{R,L}^2-T_C)=80/2=40m/s,$ Due to v _mv green time not more than needed, Q _l=L _a+ n _j/ k _j=80+1/0.23=84m, therefore craspedodrome of lower cycle long green light time is T _s=G _min=15s, long green light time of turning left is T _l=T _l+ g _lay=15s+3s=18s;

Moment for another red light start time of subsidiary road, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as the red light start time at the moment for 10:00:31, transition moment T _afor 10:01:02, green light start time for 10:01:13, transition moment T _bfor 10:01:21, transition moment T _cfor 10:01:25, to T _aby the equivalent vehicle number n of wagon detector in time _l=14, T _bto T _ctime is interior is n by the equivalent vehicle number of wagon detector _j=3.Calculate track saturation flow density: k _j=n _l/ L _b=14/60=0.23, queue dissipation speed $v=L_b/(T_B-T_G^1)=60/8=7.5m/s$ With $v_m=L_b/(T_{R,C}^2-T_C)=60/4=15m/s,$ Due to v _m> v, green time not more than needed, Q=L _b+ n _j/ k _j=60+3/0.23=73m, therefore long green light time of lower cycle is T _g=T _g+ g _lay=15s+3s=18s;

Moment for the another red light start time of major trunk roads, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as the transition moment T in craspedodrome road at the moment _afor 10:01:20, green light start time for 10:01:28, transition moment T _bfor 10:01:38, transition moment T _cfor 10:01:42, to T _aby the equivalent vehicle number n of wagon detector in time _l=18, T _bto T _ctime is interior is n by the equivalent vehicle number of wagon detector _j=2.Calculate Through Lane saturation flow density: k _j=n _l/ L _a=18/80=0.225, queue dissipation speed with due to v _mv, green time, therefore craspedodrome queue length Q not more than needed _s=L _a+ n _j/ k _j=80+2/0.225=88m; The transition moment T turned left _afor 10:01:27, green light start time for 10:01:43, transition moment T _bfor 10:01:55, there is not transition moment T _c, to T _bby the equivalent vehicle number n of wagon detector in time _l=20, T _bextremely time is interior is n by the equivalent vehicle number of wagon detector _j=4, calculate track saturation flow density: the k that turns left _j=n _l/ L _a=20/80=0.25, queue dissipation speed therefore turn left queue length Q _l> L _a+ n _j/ k _j=80+4/0.25=96m, therefore craspedodrome of lower cycle long green light time T _s=T _s+ g _lay=15s+3s=18s, long green light time of turning left is T _l=G _main-T _s=80s-18s=62s;

Moment for the another red light start time of subsidiary road, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as the transition moment T of subsidiary road this moment _afor 10:01:45, green light start time for 10:02:01, transition moment T _bfor 10:02:10, there is not transition moment T _c, to T _bby the equivalent vehicle number n of wagon detector in time _l=14, T _bextremely time is interior is n by the equivalent vehicle number of wagon detector _j=11, calculate track saturation flow density of upper cycle: k _j=n _l/ L _b=14/60=0.23, queue length Q > L _b+ n _j/ k _j=60+11/0.23=108m, at the end of Effective Green Time, still has queue after wagon detector, and therefore the long green light time in lower cycle is T _g=G _minor=45s;

Moment for another red light start time of major trunk roads, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as craspedodrome road transition moment T this moment _afor 10:02:03, green light start time for 10:02:19, transition moment T _bfor 10:02:30, there is not transition moment T _c, to T _bby the equivalent vehicle number n of wagon detector in time _l=19, T _bextremely time is interior is n by the equivalent vehicle number of wagon detector _j=14, calculate Through Lane saturation flow density of upper cycle: k _j=n _l/ L _a=19/80=0.2375, queue length Q _s> L _a+ n _j/ k _j=80+14/0.2375=139m; Turn left transition moment T _afor 10:02:29, green light start time for 10:02:37, transition moment T _bfor 10:02:55, there is not transition moment T _c, to T _bthe interior equivalent vehicle number n by detecting device _l=20, T _bextremely the interior equivalent vehicle number n by wagon detector _j=27, the upper cycle that calculates turns left track saturation flow density: k _j=n _l/ L _a=20/80=0.25 queuing queue Q _l> L _a+ n _j/ k _j=80+27/0.25=188m, at the end of Effective Green Time, still has queue after the detecting device in two tracks, and therefore craspedodrome of lower cycle long green light time is

$T_S=G_{\mathrm{main}}\&times;\frac{Q_S}{Q_S+Q_L}=80s\&times;\frac{139m}{139m+180m}=35s,$ Long green light time of turning left is

$T_L=G_{\mathrm{main}}\&times;\frac{Q_L}{Q_S+Q_L}=80s\&times;\frac{188m}{139m+188m}=45s;$

Moment for another red light start time of subsidiary road, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as track transition moment T this moment this moment _afor 10:03:05, green light start time for 10:03:39, transition moment T _bfor 10:03:50, transition moment T _cfor 10:03:58, to T _btime is interior is n by the equivalent vehicle number of wagon detector _l=14, T _bto T _ctime is interior is n by the equivalent vehicle number of wagon detector _j=8, calculating track saturation flow density of upper cycle is k _j=n _l/ L _b=14/60=0.23, queue length Q=L _b+ n _j/ k _j=60+8/0.23=94m, queue dissipation speed $v=L_b/(T_B-T_G^3)=60/11=5.45m/s,$ Queue is dissipated completely, again v _m< v, has green time more than needed, then the long green light time T in lower cycle _g=T _g-g _lay=45s-3s=42s;

Moment for a red light start time of major trunk roads, statistics obtains the wagon detector data in upper cycle and signal lamp phase tranformation data as craspedodrome road transition moment T this moment _afor 10:03:50, green light start time for 10:04:59, transition moment T _bfor 10:04:35, transition moment T _cfor 10:04:40, to T _btime is interior is n by the equivalent vehicle number of wagon detector _l=20, T _bto T _cbe n by the equivalent vehicle number of wagon detector _j=2, calculate the craspedodrome road saturation flow density k in upper cycle _j=n _l/ L _a=20/80=0.25, queue dissipation speed queue is dissipated completely, again $v_m=L_a/(T_{G,L}^4-T_C)=80/19=4.21m/s,$ V _m< v, has green time more than needed, queue length Q _s=L _a+ n _j/ k _j=80+2/0.25=88m; The transition moment T turned left _afor 10:04:38, green light start time for 10:04:59, transition moment T _bfor 10:05:20, there is not transition moment T _c, to T _btime is interior is n by the equivalent vehicle number of wagon detector _l=21, T _bextremely time is interior is n by the equivalent vehicle number of wagon detector _j=20, the upper cycle that calculates turns left saturation flow density k _j=n _l/ L _a=21/80=0.26, queue length Q _l> L _a+ n _j/ k _j=80+20/0.26=157m, at the end of Effective Green Time, still has queue after detecting device, therefore the craspedodrome long green light time T in lower cycle _s=T _s-g _lay=36s-3s=33s, long green light time of turning left is T _l=G _main-T _s=80s-33s=47s.

The timing state of the signal lamp that table 1 obtains from 10:00:00

Period	Signal lamp state	Duration (s)
			10:00:00-10:00:30	Major trunk roads are kept straight on, all red lights of turning left, subsidiary road green light	30
10:00:31-10:00:57	Major trunk roads craspedodrome green light, red light of turning left, subsidiary road red light	27
			10:00:58-10:01:12	Major trunk roads craspedodrome red light, green light of turning left, subsidiary road red light	15
10:01:13-10:01:27	Major trunk roads are kept straight on, all red lights of turning left, subsidiary road green light	15
			10:01:28-10:01:42	Major trunk roads craspedodrome green light, red light of turning left, subsidiary road red light	15
10:01:43-10:02:00	Major trunk roads craspedodrome red light, green light of turning left, subsidiary road red light	18
			10:02:01-10:02:18	Major trunk roads are kept straight on, all red lights of turning left, subsidiary road green light	18
10:02:19-10:02:36	Major trunk roads craspedodrome green light, red light of turning left, subsidiary road red light	18
			10:02:37:10:03:38	Major trunk roads craspedodrome red light, green light of turning left, subsidiary road red light	62
10:03:39-10:04:23	Major trunk roads are kept straight on, all red lights of turning left, subsidiary road green light	45
			10:04:24-10:04:58	Major trunk roads craspedodrome green light, red light of turning left, subsidiary road red light	35
10:04:59-10:05:44	Major trunk roads craspedodrome red light, green light of turning left, subsidiary road red light	45
			10:05:45-10:06:26	Major trunk roads are kept straight on, all red lights of turning left, subsidiary road green light	42
10:06:27-10:06:59	Major trunk roads craspedodrome green light, red light of turning left, subsidiary road red light	33
			10:07:00-10:07:47	Major trunk roads craspedodrome red light, green light of turning left, subsidiary road red light	47

Claims (1)

1. an adaptive intersection signal control method, is characterized in that, the method is carried out according to following steps:

Step one, 1 wagon detector is installed in each track, crossing, and the distance of wagon detector and stop line is designated as L, and each wagon detector opens the bright moment for the red light gathering each phase place n-th cycle , the n-th cycle green light open the bright moment , the (n+1)th cycle red light open the bright moment , each vehicle by wagon detector time holding time t _o, wagon detector free time interval t _fand pass through the vehicle number n of detecting device;

Described phase place comprises the craspedodrome phase place at craspedodrome queue place and the phase place of turning left at queue place of turning left;

One-period extinguishes the moment for opening the bright moment from red light to green light, note G _minfor minimum green time, note g _layfor unit green light extends or the time of shortening, note G _mainfor maximum total green time of major trunk roads;

Step 2, at the end of one-period effective green time, detection data are transferred to back-end data disposal system by wagon detector, analyze the change of traffic behavior in this cycle, find out the transition moment T of wagon detector eigenstate _a, T _band T _c;

T _athat red light opens bright rear vehicle v ₁start the transition between states moment taking wagon detector for a long time, T _aafter moment, wagon detector is by vehicle v ₁take for a long time, moment T _acan be used to determine whether this phase place track exists longer vehicle platoon;

T _bthat green light opens bright rear vehicle v ₁sail out of the transition moment of wagon detector, green light open bright after, T _bbefore moment, the vehicle before stop line sails out of crossing with saturation volume rate successively, but is 0 by the vehicle number of detecting device, at T _bafterwards, vehicle is with maximum current flow rate by wagon detector, and the holding time of wagon detector and interval time reduce;

T _clast car v in vehicle queue's queue ₂by the transition between states moment of wagon detector, determine last car of queue v ₂according to being: in queue queue, during continuous vehicle passing detection device, interval time is less, when a car and its Following Car pass through detecting device interval greater than threshold value A, illustrate in Following Car not Queue here queue;

The value obtaining threshold value A according to current traffic survey data statistics is 3s;

Step 3, adopt from moment is to T _aby the vehicle number n of detecting device in time period in moment _lcalculate the vehicle density k under saturated conditions _j, then k _j=n _l/ L; Adopt from moment is to T _bdistance L between time period in moment and stop line to wagon detector calculates the dissipation speed v of vehicle queue's queue, then and then pass through T _band T _cby the vehicle number n of detecting device in time period _jcalculate the maximum queue length Q in this cycle;

(1) if there is not T _amoment, then Q < L;

(2) if there is T _amoment, then determine T further _cmoment;

If there is T in (a) _cmoment, then Q=L+n _j/ k _j;

If there is not T in (b) _cmoment, then red light of lower cycle is opened the bright moment as transition moment T _c, statistics T _bwith by the vehicle number n of detecting device in time period _j, then Q > L+n _j/ k _j;

Step 4, the signal control strategy of adjustment major trunk roads, detailed process is as described below:

Craspedodrome queue length Q is calculated respectively according to the method for step 3 _swith the queue length Q that turns left _l;

(1) if the length of two queues is all less than L, then turn left phase time and craspedodrome phase time all distribute minimum green time, i.e. T _g1=T _g2=G _min;

(2) if only have a certain queue length to be less than L, then the minimum green time T of the phase assignments at this queue place _g1=G _min, the queue that another length is more than or equal to L then needs to determine whether this queue exists transition moment T _c:

If there is transition moment T in (a) _c, then according to T _cwith to calculate in this time interval vehicle by minimum speed v needed for L _m, then have determine whether there is green light Slack Time:

If a) v _m, then there is green light Slack Time in < v, former long green light time is cut unit green light and change time g _lay, i.e. T _g2=T _g2-g _lay;

If b) v _m, then there is not green light Slack Time, namely indicate residual queue in>=v, if T _g2< G _main-T _g1, then g is added at former long green light time _lay, i.e. T _g2=T _g2+ g _layif, T _g2=G _main-T _g1, then T _g2=T _g2;

If there is not transition moment T in (b) _c, then represent at the end of green time, detecting device upstream also has queue queue, then the long green light time of this phase place is T _g2=G _main-T _g1;

(3) if the queue length of two queues is all more than or equal to L, then determine whether individual queue exists transition moment T _c, then have:

If both there is moment T in (a) _c, then determine whether each phase place has green time more than needed, perform green light according to the strategy (a) of step (2) and extend or reduce to obtain long green light time T _g1and T _g2, wherein: T _g1+ T _g2≤ G _main;

If there is moment T in (b) queue _c, there is not moment T in another _c, then there is moment T _cphase place according to the strategy (a) of step (2) perform green light extend or reduce to obtain long green light time T _g1, there is not moment T _cthe green time of phase place be T _g2=G _main-T _g1;

If neither there is transition moment T in (c) _c, then according to Q _sand Q _llength ratio distribute the green time of phase place and craspedodrome phase place of turning left, namely $\left\{\begin{array}{c}{T}_L=G_{\mathrm{main}}\&times;\frac{Q_L}{Q_L+Q_S}\\ T_S=G_{\mathrm{main}}\&times;\frac{Q_S}{Q_L+Q_S}\end{array}\right.$

Wherein: T _lthe long green light time of phase place of turning left, T _sthe long green light time of craspedodrome phase place, Q _scraspedodrome phase alignment length, Q _lphase alignment length of turning left;

Step 5, the signal control strategy of adjustment subsidiary road, detailed process is as described below:

Subsidiary road is kept straight on and is turned left and to be controlled by a phase place, remembers G _minorfor the maximum green time of subsidiary road, G _minfor minimum green time, g _layfor unit green light extends or the time of shortening, first calculate the queue length Q of subsidiary road according to the method for step 3, T _gfor subsidiary road green time;

(1) if queue length Q < is L, then Minimum Green Time T is distributed _g=G _min;

(2) if queue length Q>=L, then transition moment T is determined whether there is _c, then have:

If there is transition moment T in (a) _c, then according to T _cwith to calculate in this time interval vehicle by minimum speed v needed for L _m, then have determine whether there is green light Slack Time:

If a) v _m, then there is green light Slack Time, then T in < v _g=T _g-g _lay;

If b) v _m, then there is not green light Slack Time, namely indicate residual queue in>=v, if T _g< G _minor, then T _g=T _g+ g _layif, T _g=G _minor, then T _g=T _g;

If there is not transition moment T in (b) _c, then T _g=G _minor.