CN104408944A - Lamp group based mixed traffic flow signal timing optimization method - Google Patents

Abstract

The invention provides a lamp group based mixed traffic flow signal timing optimization method, which comprises the steps of numbering each lamp group; setting a target function to be solved, wherein the target function takes the shortest period as a solving target, or takes the shortest period as a solution or takes the maximum traffic capacity as a solution; setting constraint conditions of the target function; writing a non-linear optimization solving program according to the target function and the constraint conditions; and finally acquiring an optimization timing result. The method provided by the invention has the advantages and beneficial effects that a signal timing scheme can be flexibly adjusted in allusion to flow requirements of different lamp groups, a concept of phase position is not used, turn-on of the lamp groups is not affected by other traffic flows at the same phase position any more, and the green lamp turn-on time of different traffic flows can be connected flexibly so as to achieve maximization of the traffic efficiency of a road crossing; and the traffic safety of non-motorized vehicles and pedestrians can be effectively ensured, and solving is conducted simply and conveniently.

Description

A kind of mixed traffic flow signal timing optimization method based on lamp group

Technical field

The invention belongs to timing signal and optimize timing technical field, especially relate to a kind of mixed traffic flow signal timing optimization method based on lamp group.

Background technology

Bicycle and pedestrian's quantity of some urban road intersections are more, and the large percentage occupied in intersection traffic composition, and the mutual serious interference between various mode traffic flow, have the feature of mixed traffic flow.Particularly electric bike and increasing rapidly of moped make the speed interval of urban road intersection traffic flow expand further in recent years, cover the automobile traffic Flow Velocity of the pedestrian traffic Flow Velocity of 3 ~ 5km/h, the Manpower Transportation Flow Velocity of 10 ~ 35km/h and 50 ~ 80km/h, it is more complicated that this makes the signal of crossing control.

In prior art, it is generally acknowledged when being provided with bicycle signal lamp, bicycle long green light time equals the difference that motor vehicle green light duration deducts motor vehicle green light interval time and bicycle copper sulfate basic.But the computing method of this bicycle green time do not consider that the reality of bicycle is passed through demand, and be not suitable for Manpower Transportation amount larger time situation.And, from practical operation situation, seldom there is the crossing that bicycle special signal is set.Due to the difference of operation characteristic, there is larger difference in bicycle and the motor vehicle copper sulfate basic required separately when green light end empties.Especially, for left-turn non-motor and motor vehicle, comparatively large owing to emptying distance, the difference of copper sulfate basic is more obvious.In this case, when still adopting bicycle and motor vehicle to share phase place, green light terminates rear bicycle and cannot pass through in corresponding copper sulfate basic, thus causes potential safety hazard.

In addition, often first determine phase structure about the research of signal optimizing model under the non-separation condition of machine, then carry out the optimization of phase sequence, greatly limit the scope of prioritization scheme like this.

Summary of the invention

The problem to be solved in the present invention is to provide a kind of mixed traffic flow signal timing optimization method based on lamp group, using urban road signalized crossing mixed traffic flow as research object, the time resource configuration of selective analysis how appropriate design mixed traffic crossing, improves the traffic efficiency of crossing.

For solving the problems of the technologies described above, the technical solution used in the present invention is:

Based on a mixed traffic flow signal timing optimization method for lamp group, comprise following steps:

1) each lamp group is numbered;

2) setting solves objective function:

Objective function is meet cycle the shortest objective function for solving target or with the minimum objective function for solving of satisfied delay or be the objective function solved with Maximum Traffic Capacity;

3) constraint condition of Offered target function;

4) write nonlinear optimization solver according to objective function and constraint condition, finally draw and optimize timing result.

The described mixed traffic flow signal timing optimization method based on lamp group, specifically comprises following steps:

1) each lamp group is numbered:

Lamp group is independent control unit minimum in integrative design intersection, can by various flows in each entrance driveway to motor vehicle, bicycle and pedestrian be defined as a lamp group respectively, and by being numbered clockwise or counterclockwise;

2) setting solves objective function:

The shortest in solving target to meet the cycle, objective function is as follows:

f＝min C (1)

In formula: f is objective function; C is cycle duration, unit second;

Or minimum for solving target with the cycle delay of motor vehicle and bicycle, objective function is as follows:

$\text{Z=min}(\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{d}_{\mathrm{Mi}}+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{d}_{\mathrm{Bi}})---\left(2\right)$

In formula: dMi is the delay of automotive lamp group i, unit second; DBi is the delay of non-maneuver car light group i, unit second; I is lamp group #; M is automotive lamp group sum; N is non-maneuver car light group sum;

For any unsaturated motor vehicle wagon flow or lamp group wagon flow, formula (3) computation period all can be used to incur loss through delay:

$d_{\mathrm{Mi}}=0.9(\frac{s_i{(1-{\mathrm{\Λ}}_i)}^2\×C}{2(s_i-q_i)}+\frac{q_i}{2s_i{\mathrm{\Λ}}_i(s_i{\mathrm{\Λ}}_i-q_i)})---\left(3\right)$

In formula: si is saturation volume, unit/second; C is cycle duration, unit second; The flow of qi corresponding to lamp group, unit/second; Λ _ifor the ratio of effective green time and cycle duration; That is,

${\mathrm{\Λ}}_i=\frac{g_i+e}{C}---\left(4\right)$

In formula: gi is the long green light time of any automotive lamp group i, unit second; E is amber light duration and the difference starting lost time, unit second;

For the delay of bicycle, available formula (5) calculates:

$d_{\mathrm{Bi}}=\frac{0.5C{(1-\frac{g_i}{C})}^2}{1-\left[\frac{g_i}{C}\min (\frac{q_i}{s_i},1)\right]}---\left(5\right)$

In formula: parameter meaning is the same;

Or with Maximum Traffic Capacity for solving target, the following formula of objective function (6) represents:

$\text{f=max}\underset{i=1}{\overset{M+N}{\mathrm{\Σ}}}{s}_i(g_i+e)---\left(6\right)$

In formula: parameter meaning is the same;

3), when above-mentioned objective function solves, following constraint condition should be given:

1. green light opens bright time-constrain

$\begin{array}{cc}C\≥g{b}_i\≥0& \∀i=\mathrm{1,2},...,M+N---\left(7\right)\end{array}$

In formula: gbi is that the green light of arbitrary lamp group i within certain cycle opens bright moment apart from mistiming of period start time, unit second;

2. minimum long green light time constraint:

For mixed traffic crossing, the slow-moving traffics such as pedestrian and non motorized vehicle are that the present invention needs the special traffic main body considered, therefore, the present invention must meet the demand of pedestrian's street crossing, ensures that pedestrian's green time is not less than the shortest time of pedestrian by crossing:

$C>g_i\≥g_{\min }\∀i=\mathrm{1,2},...,M+N---\left(8\right)$

In formula: gmin for pedestrian is by the shortest time needed for crossing, unit second;

3. the Capacity Constraints of each track group

When carrying out signal timing dial, also should be noted that this volume of traffic demand corresponding to lamp group of long green light time demand fulfillment of each lamp group; That is: the traffic capacity in each lamp group arbitrary cycle all must be more than or equal to lamp group traffic demand, specifically calculate as shown in formula (9):

$\begin{array}{cc}(g_i+e)s_i\×0.9\≥q_i\×C& \∀i,j=\mathrm{1,2},...,M+N---\left(9\right)\end{array}-$

4. copper sulfate basic constraint

Copper sulfate basic refers to that any two exist the minimum interval that must arrange between the lamp group of conflict, when carrying out signal timing dial and calculating, must ensure that the mistiming between two conflict lamp groups must be more than or equal to copper sulfate basic, the available formula of this constraint (10) represents:

gb _i+g _i+I _ij≤gb _j(10)

In formula: Iij is the copper sulfate basic between two any lamp groups, unit second;

5. the constraint of cycle duration C

When carrying out singnal configuration design, needing to arrange certain scope to cycle duration, when the volume of traffic is less, the higher limit of cycle duration can be turned down; Otherwise then heighten, the available formula of this constraint (11) represents:

C _min≤C≤C _max(11)

In formula, Cmin is the cycle duration minimum value arranged, unit second; Cmax is the cycle duration maximal value arranged, unit second; All the other parameters are the same;

4) solve:

According to above-mentioned objective function and constraint condition, write nonlinear optimization solver, finally draw and optimize timing result.

The advantage that the present invention has and good effect are:

(1) propose a kind of mixed traffic flow signal timing optimization technology based on lamp group, this technology can solve the signal timing optimization scheme of cycle minimum, mixed traffic flow when incuring loss through delay minimum and Maximum Traffic Capacity respectively;

(2) the signal timing optimization technology based on lamp group used can adjust signal time distributing conception flexibly for the traffic demand of different lamp group, do not use the concept of phase place, lamp group open the bright impact being no longer subject to same other wagon flows of phase place, the green light that can be connected different wagon flow neatly opens the bright time, to reach the maximization of intersection benefit;

(3) the present invention effectively can ensure the current safety of bicycle and pedestrian, solves easy.

Accompanying drawing explanation

Fig. 1 is method flow diagram of the present invention;

Fig. 2 is geometric space layout and the entrance driveway lane function division channelized picture of one embodiment of the invention crossing;

Fig. 3 is one embodiment of the invention to meet the cycle the shortest signal time distributing conception schematic diagram obtained for the target solved.

Embodiment

The present invention is directed to existing signal timing dial method do not take into full account the current needs of bicycle and pedestrian and empty security problems, develop a kind of mixed traffic flow signal timing optimization method based on lamp group, make up existing method and rationally cannot solve complicated mixed traffic flow signal timing dial method.Core concept of the present invention is by setting up nonlinear optimization solving model, considers the constraint such as traffic demand, copper sulfate basic, cycle duration of motor vehicle, non-maneuver and pedestrian, is optimized solves the signal timing dial of mixed traffic flow.

Below in conjunction with accompanying drawing, embodiments of the invention are elaborated.

The timing designing of the signalized crossing of mixed traffic flow is there is in one embodiment of the invention for somewhere one as shown in Figure 2, Figure 1 shows that geometric space layout and the entrance driveway lane function division condition diagram of the present embodiment crossing, can find out, four entrance driveway all have bicycle lane to exist; And there is a corner triangular island, the traffic flow of crossing runs comparatively complicated.Under tale quale, signal period C is 240 seconds, and four phase signals calculated for typical Webster method are arranged.

In the present embodiment, carry out of method to the magnitude of traffic flow of each flow direction of video recording observation is adopted to gather and add up.And the calculating of saturation volume is carried out by recording the saturation headway of each lamp group in operational process.

Mixed traffic flow signal timing optimization method based on lamp group of the present invention, as shown in Figure 1, comprises the steps:

Step 1, is numbered each lamp group:

Lamp group is independent control unit minimum in integrative design intersection, can by various flows in each entrance driveway to motor vehicle, bicycle and pedestrian be defined as a lamp group respectively, and by being numbered clockwise or counterclockwise;

Owing to there is not straight right lane in the crossing of the present embodiment, therefore lamp group divides comparatively simple, and the motor vehicle that each entrance driveway respectively flows to and bicycle are a lamp group separately; Conflict because right-hand rotation bicycle only has with the pedestrian of its side direction, and the bicycle speed of a motor vehicle is comparatively slow, therefore signal control is not implemented to it, namely lamp group # is not carried out to it; As shown in Figure 1, lamp group K represents concrete lamp group #;

Step 2, setting solves objective function, difference according to the actual requirements can select to meet the cycle the shortest for solve target or with the cycle delay of motor vehicle and bicycle minimum for solve target or with Maximum Traffic Capacity for solving target, concrete grammar is as follows:

The shortest in solving target to meet the cycle, objective function is as follows:

f＝min C (1)

In formula: f is objective function; C is cycle duration, unit second, and wherein the formula of cycle duration can be selected existing to the computing formula in the method for timing signal timing;

Or minimum for solving target with the cycle delay of motor vehicle and bicycle, objective function is as follows:

$\text{Z = min}(\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{d}_{\mathrm{Mi}}+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{d}_{\mathrm{Bi}})---\left(2\right)$

In formula: dMi is the delay of automotive lamp group i, unit second; DBi is the delay of non-maneuver car light group i, unit second; I is lamp group #; M is automotive lamp group sum; N is non-maneuver car light group sum;

For any unsaturated motor vehicle wagon flow or lamp group wagon flow, formula (3) computation period all can be used to incur loss through delay:

$d_{\mathrm{Mi}}=0.9(\frac{s_i{(1-{\mathrm{\Λ}}_i)}^2\×C}{2(s_i-q_i)}+\frac{q_i}{2s_i{\mathrm{\Λ}}_i(s_i{\mathrm{\Λ}}_i-q_i)})---\left(3\right)$

In formula: si is saturation volume, unit/second; C is cycle duration, unit second; The flow of qi corresponding to lamp group, unit/second; Λ _ifor the ratio of effective green time and cycle duration; That is,

${\mathrm{\Λ}}_i=\frac{g_i+e}{C}---\left(4\right)$

In formula: gi is the long green light time of any automotive lamp group i, unit second; E is amber light duration and the difference starting lost time, unit second;

For the delay of bicycle, available formula (5) calculates:

$d_{\mathrm{Bi}}=\frac{0.5C{(1-\frac{g_i}{C})}^2}{1-\left[\frac{g_i}{C}\min (\frac{q_i}{s_i},1)\right]}---\left(5\right)$

In formula: parameter meaning is the same;

Or with Maximum Traffic Capacity for solving target, the following formula of objective function (6) represents:

$\text{f = max}\underset{i=1}{\overset{M+N}{\mathrm{\Σ}}}{s}_i(g_i+e)---\left(6\right)$

In formula: parameter meaning is the same;

Step 3, when above-mentioned objective function solves, should give following constraint condition:

1. green light opens bright time-constrain

$\begin{array}{cc}C\≥g{b}_i\≥0& \∀i=\mathrm{1,2},...,M+N---\left(7\right)\end{array}$

In formula: gb _ifor the green light of arbitrary lamp group i within certain cycle opens bright moment apart from mistiming of period start time, unit second;

2. minimum long green light time constraint:

For mixed traffic crossing, the slow-moving traffics such as pedestrian and non motorized vehicle are that the present invention needs the special traffic main body considered, therefore, the present invention must meet the demand of pedestrian's street crossing, ensures that pedestrian's green time is not less than the shortest time of pedestrian by crossing:

$C>g_i\≥g_{\min }\∀i=\mathrm{1,2},...,M+N---\left(8\right)$

In formula: gmin, for pedestrian is by the shortest time needed for crossing, determines according to concrete pedestrian crossing length, unit second;

3. the Capacity Constraints of each track group

When carrying out signal timing dial, also should be noted that this volume of traffic demand corresponding to lamp group of long green light time demand fulfillment of each lamp group; That is: the traffic capacity in each lamp group arbitrary cycle all must be more than or equal to the traffic demand of track group corresponding to lamp group, specifically calculates as shown in formula (9):

$\begin{array}{cc}(g_i+e)s_i\×0.9\≥q_i\×C& \∀i,j=\mathrm{1,2},...,M+N---\left(9\right)\end{array}-$

4. copper sulfate basic constraint

Copper sulfate basic refers to that any two exist the minimum interval that must arrange between the lamp group of conflict, when carrying out signal timing dial and calculating, must ensure that the mistiming between two conflict lamp groups must be more than or equal to copper sulfate basic, the available formula of this constraint (10) represents:

gb _i+g _i+I _ij≤gb _j(10)

In formula: Iij is the copper sulfate basic between two any lamp groups, unit second; Gbj is that the conflict green light of lamp group within certain cycle opens the mistiming of bright moment apart from period start time, unit second;

5. the constraint of cycle duration C

When carrying out singnal configuration design, needing to arrange certain scope to cycle duration, when the volume of traffic is less, the higher limit of cycle duration can be turned down; Otherwise then heighten, the available formula of this constraint (11)

Represent:

C _min≤C≤C _max(11)

In formula, Cmin is the cycle duration minimum value arranged, unit second; Cmax is the cycle duration maximal value arranged, unit second; All the other parameters are the same; In the present embodiment, Cmin gets 120 seconds, and Cmax gets 240 seconds;

Step 4, solves:

According to above-mentioned objective function and constraint condition, write nonlinear optimization solver, matlab can be adopted to solve nonlinear equation, finally draw and optimize timing result;

The flow corresponding to each lamp group in the present embodiment in objective function and saturation volume data as shown in the table:

The flow of each lamp group of table 1 and saturation volume (unit ,/hour)

Lamp group #	1	2	3	4	5	6	7	8	9	10	11	12
													Flow qi	162	936	612	180	852	126	315	1533	144	738	1365	200
Saturation volume si	3200	6000	1800	1600	3600	1800	1600	5400	1600	3200	5400	1600
													Lamp group #	13	14	15	16	17	18	19	20	21	22	23	24
Flow qi	300	400	300	400	300	400	300	400	200	200	200	200

Saturation volume si

3000

3000

3000

3000

3000

3000

3000

3000

5000

5000

5000

5000

Green light interval Iij matrix in the present embodiment between each conflict lamp group is as shown in table 2;

Table 2 green light interim matrix (unit, second)

Under usual condition, amber light duration is 2 seconds with starting the difference e of lost time, also gets this value in the present embodiment.

The present embodiment writes nonlinear optimization solver to meet the cycle the shortest objective function for solving in conjunction with constraint condition, a variable is only had in objective function, i.e. cycle C, variable in all the other constraint conditions all needs to solve, because the result that this method will obtain is not merely one-period value, also need the initial time and the long green light time that obtain corresponding lamp group; The present embodiment is the minimum value of trying to achieve under the prerequisite meeting each constraint condition, and it is 203 seconds that Optimization Solution obtains period m inC, and concrete signal timing scheme as shown in Figure 3.

Keep straight on due to eastern import in the crossing of the present embodiment and the throughput ratio of left-hand rotation is greater than western import, western import is kept straight on to keep straight on eastern import and is carried out overlap joint and process by prioritization scheme, namely, 1. western import craspedodrome and eastern import are first let pass simultaneously, 2. after western import craspedodrome terminates, east import is kept straight on and is continued to turn left to let pass with eastern import simultaneously, and 3. eastern import is kept straight on and terminated, and thing turns left to let pass simultaneously.

Signal timing optimization method of the present invention does not use the concept of phase place, lamp group open the bright impact being no longer subject to same other wagon flows of phase place, thus timing is more flexible.And traditional Webster signal timing dial method needs to determine phase place and phase sequence in advance, by comparison, the green light that the signal optimizing method based on lamp group can be connected different wagon flow neatly opens the bright time, to reach the maximization of intersection benefit.

Above embodiments of the invention have been described in detail, but described content being only preferred embodiment of the present invention, can not being considered to for limiting practical range of the present invention.All equalizations done according to the present patent application scope change and improve, and all should still belong within patent covering scope of the present invention.

Claims (2)

1., based on a mixed traffic flow signal timing optimization method for lamp group, it is characterized in that comprising following steps:

1) each lamp group is numbered;

2) setting solves objective function:

Objective function is meet cycle the shortest objective function for solving target or with the minimum objective function for solving of satisfied delay or be the objective function solved with Maximum Traffic Capacity;

3) constraint condition of Offered target function;

4) write nonlinear optimization solver according to objective function and constraint condition, finally draw and optimize timing result.

2. the mixed traffic flow signal timing optimization method based on lamp group according to claim 1, is characterized in that comprising following steps:

1) each lamp group is numbered:

Lamp group is independent control unit minimum in integrative design intersection, can by various flows in each entrance driveway to motor vehicle, bicycle and pedestrian be defined as a lamp group respectively, and by being numbered clockwise or counterclockwise;

2) setting solves objective function:

The shortest in solving target to meet the cycle, objective function is as follows:

f＝min C (1)

In formula: f is objective function; C is cycle duration, unit second;

Or minimum for solving target with the cycle delay of motor vehicle and bicycle, objective function is as follows:

$Z=\min (\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{d}_{\mathrm{Mi}}+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{d}_{\mathrm{Bi}})---\left(2\right)$

In formula: dMi is the delay of automotive lamp group i, unit second; DBi is the delay of non-maneuver car light group i, unit second; I is lamp group #; M is automotive lamp group sum; N is non-maneuver car light group sum;

For any unsaturated motor vehicle wagon flow or lamp group wagon flow, formula (3) computation period all can be used to incur loss through delay:

$d_{\mathrm{Mi}}=0.9(\frac{s_i{(1-{\mathrm{\Λ}}_i)}^2\×C}{2(s_i-q_i)}+\frac{q_i}{2s_i{\mathrm{\Λ}}_i(s_i{\mathrm{\Λ}}_i-q_i)})---\left(3\right)$

In formula: si is saturation volume, unit/second; C is cycle duration, unit second; The flow of qi corresponding to lamp group, unit/second; Λ _ifor the ratio of effective green time and cycle duration; That is,

${\mathrm{\Λ}}_i=\frac{g_i+e}{C}---\left(4\right)$

In formula: gi is the long green light time of any automotive lamp group i, unit second; E is amber light duration and the difference starting lost time, unit second;

For the delay of bicycle, available formula (5) calculates:

$d_{\mathrm{Bi}}=\frac{0.5C{(1-\frac{g_i}{C})}^2}{1-\left[\frac{g_i}{C}\min (\frac{q_i}{s_i},1)\right]}---\left(5\right)$

In formula: parameter meaning is the same;

Or with Maximum Traffic Capacity for solving target, the following formula of objective function (6) represents:

$f=\max \underset{i=1}{\overset{M+N}{\mathrm{\Σ}}}{s}_i(g_i+e)---\left(6\right)$

In formula: parameter meaning is the same;

3), when above-mentioned objective function solves, following constraint condition should be given:

1. green light opens bright time-constrain

$C\≥{\mathrm{gb}}_i\≥0,\∀i=\mathrm{1,2},...,M+N---\left(7\right)$

In formula: gbi is that the green light of arbitrary lamp group i within certain cycle opens bright moment apart from mistiming of period start time, unit second;

2. minimum long green light time constraint:

For mixed traffic crossing, the slow-moving traffics such as pedestrian and non motorized vehicle are that the present invention needs the special traffic main body considered, therefore, the present invention must meet the demand of pedestrian's street crossing, ensures that pedestrian's green time is not less than the shortest time of pedestrian by crossing:

$C>g_i\≥g_{\min },\∀i=\mathrm{1,2},...,M+N---\left(8\right)$

In formula: gmin for pedestrian is by the shortest time needed for crossing, unit second;

3. the Capacity Constraints of each track group

When carrying out signal timing dial, also should be noted that this volume of traffic demand corresponding to lamp group of long green light time demand fulfillment of each lamp group; That is: the traffic capacity in each lamp group arbitrary cycle all must be more than or equal to lamp group traffic demand, specifically calculate as shown in formula (9):

$(g_i+e)s_i\×0.9\≥q_i\×C,\∀i,j=\mathrm{1,2},...,M+N---\left(9\right)$

4. copper sulfate basic constraint

Copper sulfate basic refers to that any two exist the minimum interval that must arrange between the lamp group of conflict, when carrying out signal timing dial and calculating, must ensure that the mistiming between two conflict lamp groups must be more than or equal to copper sulfate basic, the available formula of this constraint (10) represents:

gb _i+g _i+I _ij≤gb _j(10)

In formula: Iij is the copper sulfate basic between two any lamp groups, unit second;

5. the constraint of cycle duration C

When carrying out singnal configuration design, needing to arrange certain scope to cycle duration, when the volume of traffic is less, the higher limit of cycle duration can be turned down; Otherwise then heighten, the available formula of this constraint (11) represents:

C _min≤C≤C _max(11)

In formula, Cmin is the cycle duration minimum value arranged, unit second; Cmax is the cycle duration maximal value arranged, unit second; All the other parameters are the same;

4) solve:

According to above-mentioned objective function and constraint condition, write nonlinear optimization solver, finally draw and optimize timing result.