Traffic signal smooth guidance control method

Abstract

An optimization control method for guiding green wave traffic signals, involving the field of traffic signals, includes the following core steps: 1) selecting a guiding direction and a guiding channel; 2) selecting a guiding reference intersection phase; 3) calculating a smooth guiding intersection phase difference. Advantages: Subtracting the guiding green wave intersection phase difference of the braking time, the guiding green wave can enable the guided vehicle to obtain the green light signal opening time in advance at the position where the vehicle usually brakes before the stop line of each intersection along the guiding green wave channel, effectively avoiding the braking, deceleration and stopping operation and operation fluctuation of the guided vehicle, so that the vehicle can smoothly pass the next intersection, reducing the vehicle travel time and improving traffic efficiency.

Description

Technical Field

[0001] The present invention relates to the field of traffic signal mode control, and more particularly to a traffic signal guidance control method for making vehicles run smoothly. Background Art

[0002] At present, traffic signal guidance technologies include coordination, i.e. line coordination, i.e. green wave, and regional control methods based on line coordination. The absolute phase difference of intersections in these guidance technologies is based on the time obtained by dividing the length of the guiding green wave path between the phase of the intersection and the reference intersection by the set vehicle speed. Although such technology can enable the guided vehicles to continuously obtain green lights when reaching the next adjacent intersection in the guiding green wave channel without being stranded at the stop line due to red lights, the guided vehicles still have to brake, slow down significantly, and stop in front of the stop line before the green light turns on, and there are operation and operation fluctuations. Eliminating this deceleration and parking operation and operation fluctuations can further improve traffic efficiency. Summary of the invention

[0003] The purpose of the present invention is to eliminate the operation fluctuation of the brake, deceleration and parking of the guided vehicle in the guiding green wave channel, so as to further shorten the vehicle travel time and improve the traffic efficiency.

[0004] The present invention achieves the above-mentioned purpose and proposes a solution for turning on the green light in advance to avoid fluctuations in deceleration and parking operation, which is as follows:

[0005] A traffic signal smooth guidance control method, characterized by comprising the steps of:

[0006] S1 calculates the phase difference of a specific guiding intersection, which is the time difference between the phase of the ratio mode signal of each intersection of the channel and the phase of the reference intersection, and the time difference is the absolute phase difference of the guiding green wave intersection: 1) Select the guiding direction and the guiding road channel; 2) Select the guiding reference intersection phase: the phase of an intersection in the set channel; 3) Calculate the phase difference of a specific guiding intersection: subtract the safe braking time Tb required for braking to stop in front of the stop line at the set speed from the phase difference of the guiding intersection of each intersection of the channel, and obtain the specific absolute phase difference of each intersection, which is the phase difference of the specific guiding intersection, that is, the phase difference of the line-stable guiding intersection, a kind of the phase difference of the stable guiding intersection;

[0007] S2 configures the smooth guidance transition period for each intersection, 1) calculates the duration of the smooth guidance transition period: divides the phase difference of the smooth guidance intersection by the period to obtain the remainder r as a transition period duration, 2) produces a transition period signal: sets the transition period duration equal to the sum of the signal duration tm in the guidance direction and the signal duration ts in the other intersection direction, i.e. r=tm+ts, and configures the corresponding signal to obtain the intersection transition period.

[0008] After each S3 intersection has completed the transitional period signal operation, it will operate its own ratio signal for the next cycle.

[0009] According to the traffic signal smooth guidance control method of the present invention, the calculation characteristics of the phase difference of the specific guidance intersection are: (1) configuring a ratio mode signal for each intersection of the channel;

[0010] (2) Calculate the phase difference of the guiding intersection, which is equal to the sum of the driving time of each section of the path between the phase of each intersection in the channel and the reference intersection. The driving time tv of each section is equal to the length d of each section divided by the set speed v0 of each section, that is, tv = d / v0. It is also the relative phase difference tv of the downstream intersection compared with the upstream intersection in the guiding direction phase between adjacent intersections, and the guiding intersection phase difference is obtained;

[0011] (3) Subtract the safe braking time Tb required for the vehicle to stop at the stop line at the set speed from the phase difference of the guiding intersections at each intersection of the channel, and the specific absolute phase difference of each intersection is obtained, which is the specific guiding intersection phase difference, that is, the linear smooth guiding intersection phase difference, which is a type of smooth guiding intersection phase difference.

[0012] According to the traffic signal smooth guidance control method of the present invention, the calculation of the phase difference of a specific guidance intersection is characterized by: 1) selecting a guidance direction and a guidance road channel: including selecting the area including one direction as a first guidance direction and another direction as a second guidance direction, and the plurality of sub-area road channels in the first guidance direction and the plurality of sub-area road channels in the second guidance direction intersect to form a plurality of intersections referred to as intersections, which may include virtual intersections and virtual connecting sections;

[0013] 2) Selecting the guidance reference intersection phase: including selecting one of the several intersections as the relevant intersection, and taking the guidance direction phase in a sub-area where the relevant intersection is located as the reference intersection phase; determining the green light on time of the reference intersection phase and the green-to-signal ratio time distribution of the relevant intersection, or further selecting the intersection downstream of the reference intersection phase as the secondary reference intersection phase; the reference intersection phase can be selected as any intersection phase in principle, which is set according to the actual situation. Taking the intersection at one corner of the entire area including the virtual intersection as the reference intersection phase is also an option;

[0014] 3) Calculation of phase differences at specific guiding intersections: including calculation of regional smooth guiding intersection phase differences at each intersection in the area: based on the green light on-time of the reference intersection phase and the sub-reference phase, and the linear smooth guiding intersection phase difference of the road path of the same direction phase guided by the green wave between the phases of each intersection in the area and the reference intersection phase or the sub-reference phase, i.e., the guiding path, calculate the green light on-time of the remaining smooth guiding phases, thus obtaining the regional smooth guiding intersection phase differences at the remaining intersections in the area.

[0015] According to the traffic signal smooth guidance control method described in the previous paragraph of the present invention, the calculation characteristics of the phase difference of a specific guiding intersection are: 1) calculating the guiding intersection phase difference based on one of the reference intersection phase and the secondary reference intersection phase and each intersection downstream of the related guiding direction channel; 2) calculating the linear smooth guiding intersection phase difference of each intersection, that is, the guiding intersection phase difference minus the braking time Tb; 3) respectively calculating the guiding intersection phase difference based on the reference intersection phase of each intersection and the other phase of the secondary reference intersection phase and each intersection downstream of the guiding direction channel, which is called the guiding intersection phase difference in the other direction; 4) respectively calculating the linear smooth guiding intersection phase difference in the other direction, that is, the guiding intersection phase difference in the other direction minus the braking time Tb, to obtain the linear smooth guiding intersection phase difference in the other direction, that is, the regional smooth guiding intersection phase difference.

[0016] According to the traffic signal smooth guidance control method of the present invention, the characteristics of making transition period signals include: for a transition period that is too short, directly making it an equal-length red light time or allocating it to the green light time of the current cycle, that is, realizing the transition period in the form of extending the red light or green light time; or for a transition period close to one cycle, directly reducing the signal length of the current cycle and the cycle complement of the transition period, that is, realizing the transition period in the form of shortening the red light or green light time.

[0017] The advantages of the present invention are as follows: the specific guiding green wave with the guiding green wave intersection phase difference minus the braking time can enable the guided vehicle to obtain the green light signal in advance at the position where the vehicle usually brakes before the stop line of each intersection along the guiding green wave channel, effectively avoiding the braking, deceleration and stopping operation and operation fluctuation of the guided vehicle, so that the vehicle can pass the next intersection smoothly, reducing the vehicle travel time and improving traffic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a timing diagram of a stable line guiding embodiment of the present invention, including Figure 1 -a line stable guidance example channel structure diagram and Figure 1 -b line steady guidance embodiment time distance schematic diagram;

[0019] Figure 2 It is a schematic diagram of the structure of an embodiment of regional stable guidance of the present invention;

[0020] Figure 3 Schematic diagram of the flow chart of the line steady guidance control method;

[0021] Figure 4 Flow chart of regional stable guidance control method;

[0022] Reference number in the accompanying drawings: None. DETAILED DESCRIPTION

[0023] Two embodiments of the present invention are described in detail with reference to the accompanying drawings:

[0024] Embodiment 1, as Figure 1 The line steady guide signal embodiment of the present invention shown includes Figure 1 -a and Figure 1 -b; Figure 1 -a shows six intersections of the line smooth guidance embodiment channel, I-1 to I-6, one of which is the relevant intersection I-6 with the reference phase of the guidance direction, guiding the black arrow representing the westbound traffic flow, and the length of the section (meters) and the driving time (seconds) at the prescribed speed of 45 kilometers per hour are marked between adjacent intersections, such as 375 / 30 means that the section length is 375 meters / driving time is 30 seconds; Figure 1 -b shows the time distance diagram of the embodiment of the line smooth guidance, in which 6 groups of short thick vertical dashed lines, the solid line represents the green light time of the straight phase of the corresponding intersection below, that is, the phase difference of the smooth guidance intersection and the green light opening position, the duration is 30 seconds, and there are two horizontal lines near the lower end, the dashed line represents the phase difference of the guidance intersection, the thick dotted line represents the phase difference of the smooth guidance intersection, the interval between the two lines represents that the braking time Tb of the specified speed of 45 kilometers per hour is about 3 seconds, the dashed line represents the phase difference of the guidance intersection and the green light opening position is behind, the interval Db between the two dashed lines represents that the distance traveled by the specified speed braking time Tb is about 20 meters, the entire Figure 1 The green light opening time of each intersection phase is displayed, and the position Db before the braking time Tb before the vehicle arrives at the intersection is avoided, and the operation and operation fluctuation of the vehicle's braking deceleration and stopping are avoided; (the same labels in other figures below represent the same meaning);

[0025] The configuration method of the line steady guide signal embodiment is as follows Figure 3 ,

[0026] S1 calculates the phase difference of a specific guiding intersection: 1) Selects the guiding direction and the guiding road channel: Selects the west direction as the guiding direction, i.e., the intersection signal direction is east, and the selected guiding road channel is a 6-intersection channel, I-1, I-2, I-3, I-4, I-5, I-6; 2) Selects the reference intersection phase: Selects the straight phase of the intersection I-6 signal direction east, i.e., the guiding direction west, in the channel as the reference intersection phase; Other intersections can also be selected as reference intersection phases as needed, such as I-5, and calculates the corresponding phase difference; 3) Calculation of the phase difference of a specific guiding intersection: (1) Configures a ratio mode signal for each intersection of the channel: Configures a ratio signal with no time difference and the same period, i.e., a ratio mode signal, for each intersection of the channel, with a period of 90 seconds, a duration of 45 seconds for each direction, and a straight-through turn diversion ratio of 2:1, i.e., a straight-through phase of 30 seconds and a turning phase of 15 seconds, (2) Calculates the phase difference of the guiding intersection , with the reference intersection phase, the diversion phases of the adjacent intersections of the road in the same direction are configured so that the vehicle flow direction guided by the green wave between the adjacent intersections, that is, the downstream intersection of the guiding direction phase, increases an intersection relative phase difference compared with the upstream intersection, that is, the time tv required for the vehicle of the section to travel the entire section d at the set speed v0 = 12.5 meters per second, that is, 45 kilometers per hour, is increased, that is, tv = d / v0, and the guiding intersection phase difference is obtained, 141, 111, 85, 58, 30, 0; (3) the phase difference of each line guiding intersection of each intersection downstream of the guiding direction of the reference intersection phase is subtracted from the safe braking time Tb required to stop at the stop line at the set speed, which is about 3, and the corresponding braking distance Db is about 20 meters, and the specific guiding intersection phase difference of each intersection, that is, the line stable guiding intersection phase difference is obtained, 141-3, 111-3, 85-3, 58-3, 30-3, 0;

[0027] Embodiment 2, as Figure 2 The presented regional stable guidance signal embodiment of the present invention,

[0028] The configuration method of the regional stable guidance signal embodiment is as follows Figure 4 ,

[0029] S12 calculates the phase difference of a specific guidance intersection:

[0030] 1) Selecting a guiding direction and a guiding road channel: Selecting the area includes a north direction as a first guiding direction and a west direction as a second guiding direction, wherein the 7 north-direction guiding the first guiding direction, a1, a2, a3, a4, a5, a6, a7, and the 5 west-direction guiding the second guiding direction, b1, b2, b3, b4, b5, intersect to form 32 intersections, i.e., intersections I-1 to I-32, and also include virtual intersections, i.e., I-33 to I-40 marked with dashed small squares, and virtual connecting sections, and configuring ratio mode signals for the intersections of the two directions;

[0031] 2) Selecting the guiding reference intersection phase: Select one of the 32 intersections as the relevant intersection, that is, intersection I-27 is selected as the relevant intersection, and the guiding direction north straight phase in a sub-area where the relevant intersection is located is used as the reference intersection phase, to guide the 4 northbound traffic flows marked by hollow arrows, I-24, I-25, I-26, and I-27; through the green light on time of the reference intersection phase and the green-to-signal ratio time allocation of the relevant intersection, determine the guiding direction west straight phase of the relevant intersection in another sub-area as the green light on time of the secondary reference phase, and select the intersection downstream of the reference intersection phase as The secondary reference intersection phase, that is, the downstream intersections in the north direction guided by the reference intersection phase are I-21, I-14, and I-6 in order of near and far. The east direction of these intersection signals, that is, the west direction is guided by the secondary reference phase to guide the west direction, so as to guide the four westbound traffic flows marked by thick arrows, I-27, I-21, I-14, and I-6; in principle, the reference intersection phase can be any intersection, which is set according to the actual situation. It is also an option to use an intersection at a corner of the entire area including the virtual intersection as the reference intersection phase. For example, I-40 is selected as the reference intersection phase, and the corresponding phase difference is calculated;

[0032] 3) Calculation of specific guiding intersection phase difference: According to the green light on time of the reference intersection phase and the secondary reference phase, and the line steady guiding intersection phase difference of the road path of the same direction diversion phase guided by the green wave between the phase of each intersection in the area and the reference intersection phase or between the secondary reference phase, that is, the guiding path, the green light on time of the steady guiding phase of the remaining intersections is calculated, that is, the specific guiding intersection phase difference of the remaining intersections in the area, that is, the regional steady guiding intersection phase difference, is obtained, as follows,

[0033] (1) The phase difference between the reference intersection phase and the guiding intersections I-27, I-21, I-14, and I-6 downstream of the north channel in the guiding direction is calculated as 0, 30, 60, and 90 degrees;

[0034] (2) The phase difference between each secondary reference phase intersection I-27, I-21, I-14, I-6 and each intersection downstream of the west channel in the guiding direction is calculated and expressed as a character array (*), as follows:

[0035] (I-1,231), (I-2,201), (I-3,175), (I-4,148), (I-5,120), (I-6,90), (I-7,60), (I-8,30);

[0036] (I-9,201), (I-10,171), (I-11,145), (I-12,118), (I-13,90), (I-14,60), (I-15,30);

[0037] (I-16,171), (I-17,141), (I-18,115), (I-19,88), (I-20,60), (I-21,30);

[0038] (I-22,147), (I-23,111), (I-24,85), (I-25,58), (I-26,30), (I-27,0);

[0039] (I-29,69), (I-30,42), (I-31,14), (I-32,-16);

[0040] (3) Calculate the phase difference of the line steady guiding intersection based on the phase of the benchmark intersection and the intersections I-27, I-21, I-14, and I-6 downstream of the north channel of the guiding direction, that is, subtract the braking time Tb of about 3 seconds from the phase difference of the guiding intersection of each intersection, and obtain the phase difference of the line steady guiding intersection as 0, 27, 57, and 87;

[0041] (4) The phase difference between the regional stable guiding intersections I-27, I-21, I-14, and I-6 and the intersections downstream of the west channel in the guiding direction is calculated and expressed as an array (#, #) as follows:

[0042] (I-1,225), (I-2,195), (I-3,169), (I-4,142), (I-5,114), (I-6,87);

[0043] (I-9,195), (I-10,165), (I-11,139), (I-12,112), (I-13,84), (I-14,57);

[0044] (I-16,165), (I-17,135), (I-18,109), (I-19,82), (I-20,54), (I-21,27);

[0045] (I-22,144), (I-23,108), (I-24,82), (I-25,55), (I-26,27), (I-27,0);

[0046] The seven upstream intersections in the two stable guiding directions of the reference intersection phase, I-7 to I-8, I-15, I-29 to I-32, are not changed in stable guiding, and the original guiding intersection phase difference is still maintained; all of these intersections can also be configured as stable guiding intersection phase difference as another embodiment;

[0047] S2. Configure smooth guidance of each intersection transition period: Make the phase difference of each area smooth guidance intersection transition period:

[0048] (1) Calculating the transition period of the regional smooth guide intersection: The remainder r obtained by dividing the phase difference of the regional smooth guide intersection by the period is used as the transition period, and the result is:

[0049] (I-1,35), (I-2,15), (I-3,79), (I-4,52), (I-5,24), (I-6,87);

[0050] (I-9,15), (I-10,75), (I-11,49), (I-12,22), (I-13,84), (I-14,57);

[0051] (I-16,75), (I-17,45), (I-18,19), (I-19,82), (I-20,54), (I-21,27);

[0052] (I-22,54), (I-23,18), (I-24,82), (I-25,55), (I-26,27), (I-27,0);

[0053] (2) Making a transition period signal: Let the transition period duration be equal to the sum of the signal duration tm for guiding the first direction and the signal duration ts for guiding the second direction, that is, r=tm+ts, and configure the corresponding signal to obtain the intersection transition period:

[0054] (I-1, 18+17), (I-2, 15), (I-3, 40+39), (I-4, 26+26), (I-5, 12+12), (I-6, 44+43);

[0055] (I-9,15), (I-10,38+37), (I-11,25+24), (I-12,11+11), (I-13,42+42), (I-14,29+28);

[0056] (I-16, 38+37), (I-17, 23+22), (I-18, 10+9), (I-19, 41+41), (I-20, 27+27), (I-21, 14+13);

[0057] (I-22, 27+27), (I-23, 9+9), (I-24, 41+41), (I-25, 28+27), (I-26, 14+13), (I-27, 0);

[0058] Among them, the transition period of the two intersections (I-2, 15) and (I-9, 15) is too short, which is less than 16. It is not suitable to make the transition period of the cross signal. The transition period is realized by extending the red light time of the current cycle; and (I-3, 79), (I-6, 87), (I-10, 75), (I-13, 84), (I-16, 75), (I-19, 82), (I-24, 82) can also realize the transition period by shortening the cycle length;

[0059] S3. After each intersection runs the transition period signal, it runs its own ratio signal: if the transition period is greater than 0, the intersection displays the transition period signal and reduces the transition period by 1 second; otherwise, the intersection runs the next cycle ratio signal.

Claims

1. Traffic signal smooth guidance control method, characterized in that Includes steps: S1 calculates the phase difference of a specific guiding intersection, which is the time difference between the phase of the ratio mode signal of each intersection of the channel and the phase of the reference intersection. This time difference is the absolute phase difference of the guiding green wave intersection: 1) Select the guiding direction and the guiding road channel; 2) Select the guiding reference intersection phase: the phase of an intersection in the set guiding road channel; 3) Calculation of phase difference of specific guiding intersections: (1) Calculate the phase difference of the guiding intersection, which is equal to the sum of the driving time of each section of the path between the phase of each intersection in the channel and the reference intersection. The driving time tv of each section is equal to the length d of each section divided by the set vehicle speed v0 of each section, that is, tv = d / v0. It is also the relative phase difference tv of the downstream intersection compared with the upstream intersection in the guiding direction phase between adjacent intersections, and the guiding intersection phase difference is obtained; (2) The phase difference of the guide intersections at each intersection of the channel is subtracted from the safe braking time Tb required for stopping at the stop line at the set speed, and the specific absolute phase difference of each intersection is obtained, which is the specific guide intersection phase difference, that is, the line stable guide intersection phase difference, which is a type of stable guide intersection phase difference; S2 configures the transition period of each intersection for smooth guidance: 1) calculates the transition period of the smooth guidance intersection: divides the phase difference of the smooth guidance intersection by the period to obtain the remainder r as a transition period, 2) makes a transition period signal: makes the transition period equal to the sum of the signal duration tm of the guidance direction and the signal duration ts of the other crossing direction, that is, r=tm+ts, and configures the corresponding signal to obtain the intersection transition period; After each intersection of S3 runs the transitional signal, it runs the next cycle of its own ratio signal; The ratio mode signal refers to configuring each intersection of the channel with a ratio signal of the same period without time difference.

2. According to the traffic signal smooth guidance control method of claim 1, the calculation characteristics of the phase difference of the specific guidance intersection are: (1) configuring ratio mode signals at each intersection of the channel; (2) Calculate the phase difference of the guiding intersection, which is equal to the sum of the driving time of each section of the path between the phase of each intersection in the channel and the reference intersection. The driving time tv of each section is equal to the length d of each section divided by the set speed v0 of each section, that is, tv = d / v0. It is also the relative phase difference tv of the downstream intersection compared with the upstream intersection in the guiding direction phase between adjacent intersections, and the guiding intersection phase difference is obtained; (3) Subtract the safe braking time Tb required for the vehicle to stop at the stop line at the set speed from the phase difference of the guiding intersections at each intersection of the channel, and the specific absolute phase difference of each intersection is obtained, which is the specific guiding intersection phase difference, that is, the linear smooth guiding intersection phase difference, which is a type of smooth guiding intersection phase difference.

3. According to the traffic signal smooth guidance control method of claim 2, the calculation of the phase difference of a specific guiding intersection is characterized by: 1) Selecting a guiding direction and a guiding road channel: including selecting an area including one direction as a first guiding direction and another direction as a second guiding direction, wherein a plurality of sub-area road channels in the first guiding direction and a plurality of sub-area road channels in the second guiding direction intersect to form a plurality of intersections referred to as intersections, which may include virtual intersections and virtual connecting sections; 2) Selecting a guidance reference intersection phase: including selecting one of the several intersections as a relevant intersection, and taking the guidance direction phase in a sub-area where the relevant intersection is located as the reference intersection phase; determining the green light on time of the reference intersection phase and the green signal ratio time distribution of the relevant intersection, or further selecting the intersection downstream of the reference intersection phase as the secondary reference intersection phase; the reference intersection phase can be selected as any intersection phase in principle, and is set according to actual conditions. Taking the intersection at one corner of the entire area including the virtual intersection as the reference intersection phase is also an option; 3) Calculation of the phase difference of specific guiding intersections: including calculating the regional smooth guiding intersection phase difference of each intersection in the area: according to the green light activation time of the reference intersection phase and the sub-reference phase, and the linear smooth guiding intersection phase difference of the road path of the same direction phase guided by the green wave between the phase of each intersection in the area and the reference intersection phase or the sub-reference phase, that is, the guiding path, calculate the green light activation time of the remaining smooth guiding phase, and obtain the specific guiding intersection phase difference of the remaining intersections in the area, that is, obtain the regional smooth guiding intersection phase difference of the remaining intersections in the area.

4. According to the traffic signal smooth guidance control method of claim 3, the calculation characteristics of the phase difference of the specific guidance intersection are: (1) calculating a guiding intersection phase difference based on one of the reference intersection phase and the secondary reference intersection phase and each intersection downstream of the relevant guiding direction channel; (2) calculating the line steady guide intersection phase difference of each intersection, that is, the guide intersection phase difference minus the braking time Tb; (3) respectively calculating the guiding intersection phase difference based on the reference intersection phase of each intersection and another phase in the secondary reference intersection phase and each intersection downstream of the guiding direction channel, which is called the guiding intersection phase difference in another direction; (4) Calculate the phase difference of the smooth guiding intersection of the other direction line respectively, that is, the phase difference of the smooth guiding intersection of the other direction line minus the braking time Tb, to obtain the phase difference of the smooth guiding intersection of the other direction line, that is, the phase difference of the regional smooth guiding intersection.

5. The traffic signal smooth guidance control method according to claim 1, wherein the transition signal making method is characterized by comprising: S31 directly makes the transition period that is too short into an equal length of red light time or distributes it into the green light time of the current cycle, that is, the transition period is realized by extending the red light or green light time; or for a transition period that is close to one cycle, directly reduce the signal duration of the current cycle and the cycle complement of the transition period, that is, the transition period is realized by shortening the red light or green light time.

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