CN104157150A - Novel single-intersection traffic signal lamp control method - Google Patents

Abstract

The invention discloses a novel single-intersection traffic signal lamp control method. The method comprises steps: (1) a decision-making model and control algorithm of signal lamps are separated, and the decision-making mathematical model is packaged to be a function; (2) a control model is brought forward to enable the red lamp-waiting time of all vehicles to be the shortest on the premise that traffic jam does not happen or the traffic ham does not deteriorate, wherein the control model is characterized in that a shortest vehicle length model is adopted, the optimal vehicle waiting time model is adopted, a phase vehicle length threshold and a general vehicle length threshold are brought forward, and the above three factors are converged to bring forward the mixed control model; and (3) a kind of decision-making algorithm is designed for the built model, planning on the red lamp and the green lamp in the future red-green-lamp cycles is realized, and a feasible plan is obtained to obtain the minimal value from the above mode, and real-time performance is facilitated. Thus, common emergency states can be well scheduled, control is real-time and the control effects are good.

Description

Novel single intersection method for controlling traffic signal lights

Technical field

The present invention relates to real-time single intersection traffic lights control decision Mathematical Models and solve the algorithm of this model.

Background technology

Along with economical and scientific and technical development, the automobile quantity in city is on the increase in recent years, and this has also brought Traffic Jam Problem in Cities.Nowadays these problems are more and more subject to people's attention, the project of some intelligent transportation is also set up in each city gradually, the information collecting devices such as camera, sensor, geomagnetic induction coil have been collected the transport information of large amount of complex, and how these data act on has proposed new higher requirement in point duty.For these crossing traffic informations, how effectively to control traffic lights and make it effectively to alleviate traffic pressure and become a study hotspot in this year.

Now, the control model and algorithm of most traffic lights is all that model is set up and mixed with two of algorithm design at the beginning of design, first establishes algorithm model, then designs according to this model feature the algorithm that solves this model.Therefore there are many problems.Wherein two kinds of problems below main existence

1, aspect modelling because model is too simplified, can not well dispatch common emergency situations as vehicle rareness, evening peak etc. early.

2, for ask effect algorithm too complexity can not control in real time, or algorithm is too simply controlled poor effect.

Summary of the invention

The object of the invention is to overcome prior art deficiency, discloses a kind of novel single intersection Traffic signal control decision model and algorithm, can well dispatch common emergency situations, controls in real time, controls effect good.

The inventive method thinking: the control decision model and algorithm of traffic lights is separated, design a more fully signal lamp decision model, then design a more effective real-time control algolithm.

Principle: the present invention separates the control decision model and algorithm of live signal lamp control problem.First having designed a kind of mixing control decision model, not there is not hommization as far as possible under the prerequisite that traffic conditions worsens in the signal lamp control decision making.Secondly, designed dynamic programming algorithm complicated signal lamp decision-making is become and can in polynomial time, be tried to achieve.Finally, in the state transitions of dynamic programming, call Hybrid Control Model, and then reach the combination of model and algorithm, make to obtain fast a signal lamp control decision with certain hommization.

For solving above technical matters, the present invention adopts following technical scheme:

Novel single intersection Traffic signal control decision model and an algorithm, is characterized in that, the method comprises the steps:

(1), for the decision model of signal lamp is separated with control algolithm, the mathematical model of decision-making is packaged into a function by the present invention, submit to this mathematical model function by the intersection information in each moment, can obtain the traffic index that a functional value represents this crossing, the lower traffic of numerical value is better, otherwise poorer.So, the mathematical model of decision-making is equivalent to black box operation for follow-up algorithm design, and changing model does not affect later algorithm decision-making.

(2), aspect modelling, the present invention does not occur blocking up or block up can not worsening as prerequisite taking traffic and allows red light stand-by period of all vehicles the shortlyest propose control model as object.Model is as follows:

(2.1), block up in order to prevent or to alleviate, the present invention adopts the shortest Vehicle length model.Being calculated to the queuing Vehicle length at each crossing a certain moment, is exactly the functional value of this pattern function to their length summation.

(2.2), in order to make all cars stand-by period fewer, the present invention has adopted optimum vehicle stand-by period model.Each car is just carried out to timing to it when it has entered vehicle waiting list, and the stand-by period that timing time is this vehicle, the corresponding a certain moment is exactly the functional value of this pattern function to the stand-by period summation of all vehicles.

(2.3), in order to merge above-mentioned two models, the present invention proposes two threshold values, i.e. phase place Vehicle length threshold value and total Vehicle length threshold value.Phase place Vehicle length threshold value is, the Vehicle length of the some phase places to a crossing proposes threshold value, and the Vehicle length that threshold value is generally this phase place just enough rolls all cars away from 2 to 5 times of (concrete coefficient is undetermined depending on concrete condition) durations of its maximum green perild.Total Vehicle length threshold value is that, to each phase place Vehicle length summation proposition threshold value, threshold value is generally just enough to be rolled all cars away within 2 to 5 times of times in standard traffic lights cycle (concrete coefficient is undetermined depending on concrete condition) all Vehicle lengths in this crossing.

(2.4), above-mentioned three elements are merged and proposed Hybrid Control Model of the present invention.The Vehicle length of each phase place of current crossing is less than when phase place Vehicle length threshold value and total Vehicle length are less than total Vehicle length threshold value and adopts optimum vehicle time Holding Model, otherwise adopts the shortest vehicle stand-by period model.Note: the Vehicle length that Vehicle length is as a comparison current time, and it is irrelevant to call the intersection information that this function imports into.

(3), for the model of having set up, the present invention will design a kind of decision making algorithm, algorithm, by the traffic lights planning realizing several traffic lights cycle in future, obtains the value minimum that a kind of feasible planning is tried to achieve above-mentioned model.And in meeting this characteristic, ensure to have higher real-time.Algorithm steps is as follows:

(3.1), the pre-service of algorithm.Algorithm pre-service comprises carries out secondary treating to the existing intersection information data that obtain, the drive away prediction of vehicle of the prediction to data analysis after treatment to future car flow and green light phase.

(3.2), algorithm model is designed to an integer programming model.The present invention this according to the least unit of traffic lights displaying time (second) as base unit, whole model can abbreviation be just that the i moment, j phase place traffic lights situation was P _ij, P _ijbe 0/1 variable, 0 represents red light, and 1 represents green light.So whole problem just can become to have various P by abbreviation _ijask a kind of planning of optimum, make the result minimum of the mathematical model set up above.Certainly P _ijalso need to meet the distinctive restriction of some traffic lights.

(3.3) design dynamic programming method according to the special nature of traffic lights and solve integer programming model.If direct solution linear programming problem, state total amount is 2 so ^n*m, n represents the time span of decision-making, m represents number of phases, can find out that this is a np problem, and in actual traffic lights control, people wish that he has very strong precision and must solve out at short notice simultaneously.But this problem itself is not pure barbaric 0/1 planning problem, itself there are some very strong constraint conditions, by the research to this 0/1 planning problem and the distinctive character of traffic lights, this problem has been made and has been revised as the integer programming problem that can use dynamic programming to solve 0/1 plan model, and finally in polynomial time, (in actual motion, time complexity is less than 1 second) solves out.

Innovative point of the present invention is embodied in:

1) control decision model and algorithm is separated.

2) design a kind of Hybrid Control Model.

3) design a kind of novel decision making algorithm: based on the dynamic programming algorithm of integer programming.

Brief description of the drawings

Fig. 1 general flow chart of the present invention

Fig. 2 control model process flow diagram

Fig. 3 decision making algorithm process flow diagram

Formula explanation

The shortest Vehicle length model of formula 1

Model of optimum vehicle stand-by period of formula 2

Formula 3 model conversion conditions

Formula 4 Hybrid Control Models

Formula 5 algorithm state equations of transfer

Embodiment

Below in conjunction with accompanying drawing and formula, technical solution of the present invention is described further.

Principle: the present invention proposes the separation to signal lamp control decision model and algorithm, and respectively model is set up on this basis and algorithm design proposition optimization.

If Fig. 1 is general flow chart of the present invention, first by model and algorithm is separated, control model encapsulation is become to the function of a black box, then constantly call pattern function by decision making algorithm subsequently, to reach decision-making object.

Fig. 2 is of the present invention set up signal lamp mathematical model, the optimum vehicle stand-by period model of his the shortest Vehicle length model based on formula (1) and formula (2) has added the decision-making value of formula (3), be combined into a complex decision model, the mathematical expression of model is formula (4).

Formula (1): L _mfor total Vehicle length, L _iit is the Vehicle length of i phase place.

Formula (2): T _nfor total vehicle stand-by period, t _iit is the stand-by period of i vehicle.

Formula (3): L _max1for phase place Vehicle length threshold value, L _max1for total Vehicle length threshold value.

Formula (4): G (t) is pattern function, the corresponding t moment of t.

$L_m=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{L}_i$

The shortest Vehicle length model of formula 1

$T_n=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{t}_i$

Model of optimum vehicle stand-by period of formula 2

L _i≤L _max1(1≤i≤m)∩L _m≤L _max2

Formula 3 model conversion conditions

$G\left(t\right)=\left\{\begin{array}{c}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{L}_i(L_i\≤L_{\max 1}\∩L_m\≤L_{\max 2})\\ \underset{i=1}{\overset{n}{\mathrm{\Σ}}}{t}_i(L_i>L_{\max 1}\∪L_m>L_{\max 2})\end{array}\right.$

Formula 4 Hybrid Control Models

$F(t,i)=\left\{\begin{array}{c}\underset{g_{\min }\≤g\≤g_{\max }}{\min }(F(t-g,i-1)+\underset{k=t-g}{\overset{t}{\mathrm{\Σ}}}G\left(k\right))(i\≠m)\\ \underset{g_{\min }\≤g\≤g_{\max }}{\min }(F(t-g,1)+\underset{k=t-g}{\overset{t}{\mathrm{\Σ}}}G\left(k\right))(i=m)\end{array}\right.$

Formula 5 algorithm state equations of transfer

If Fig. 3 is decision making algorithm flow process of the present invention, the first relative data of algorithm is carried out pre-service and the prediction to future car flow as shown in the figure, then by signal model feature is set up to integer programming model, finally use dynamic programming algorithm to solve by model feature.

Formula (5) is the state transition equation of dynamic programming algorithm, and wherein t represents the t moment, and i represents that current i crossing is green light, and g is the green time at i crossing.

In sum, whole realization flow is summarised as:

1) the control model of signal lamp is separated with decision making algorithm.

2) go out Hybrid Control Model to controlling modelling.

3) decision-making algorithm design gone out to an integer programming model and solve by dynamic programming algorithm.

Claims (1)

1. a novel single intersection method for controlling traffic signal lights, is characterized in that, the method comprises the steps:

(1), the decision model of signal lamp is separated with control algolithm:

The mathematical model of decision-making is packaged into a function, the intersection information in each moment is submitted to this mathematical model function, obtain the traffic index that a functional value represents this crossing, the lower traffic of numerical value is better, otherwise poorer;

(2), can not to worsen as prerequisite makes the red light stand-by period of all vehicles the shortest in object has proposed control model do not appear blocking up or blocking up in traffic, this control model feature is characterized by:

(2.1), adopt the shortest Vehicle length model: being calculated to the queuing Vehicle length at each crossing a certain moment, is exactly the functional value of this pattern function to their length summation;

(2.2), adopted optimum vehicle stand-by period model: each car is just carried out to timing to it when it has entered vehicle waiting list, timing time is the stand-by period of this vehicle, the corresponding a certain moment is exactly the functional value of this pattern function to the stand-by period summation of all vehicles;

(2.3), two threshold values are proposed, be phase place Vehicle length threshold value and total Vehicle length threshold value:

Phase place Vehicle length threshold value is, the Vehicle length of the some phase places to a crossing proposes threshold value, and the Vehicle length that threshold value is generally this phase place just enough rolls all cars away from 2 to 5 times of durations of its maximum green perild;

Total Vehicle length threshold value is that, to each phase place Vehicle length summation proposition threshold value, threshold value is that all Vehicle lengths in this crossing are just enough rolled away from all cars within 2 to 5 times of times in standard traffic lights cycle;

(2.4), above-mentioned three elements are merged and have proposed Hybrid Control Model: the Vehicle length of each phase place of current crossing is less than when phase place Vehicle length threshold value and total Vehicle length are less than total Vehicle length threshold value and adopts optimum vehicle time Holding Model, otherwise adopts the shortest vehicle stand-by period model;

(3), for the model of having set up, will design a kind of decision making algorithm, realize the traffic lights planning to several traffic lights cycle in future, obtain the value minimum that a kind of feasible planning is tried to achieve above-mentioned model, and real-time, step is as follows:

(3.1), the pre-service of algorithm: algorithm pre-service comprises carries out secondary treating to the existing intersection information data that obtain, the drive away prediction of vehicle of the prediction to data analysis after treatment to future car flow and green light phase;

(3.2), algorithm model is designed to an integer programming model: as base unit, whole model can abbreviation be just that the i moment, j phase place traffic lights situation was P according to the least unit of traffic lights displaying time (second) _ij, P _ijbe 0/1 variable, 0 represents red light, and 1 represents green light, and whole problem reduction becomes to have various P _ijask a kind of planning of optimum, make the result minimum of the mathematical model set up above;

(3.3) design dynamic programming method and solve integer programming model.