CN115512556A - Traffic signal control method and device for preferential passing of special vehicles - Google Patents
Traffic signal control method and device for preferential passing of special vehicles Download PDFInfo
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Abstract
The invention provides a traffic signal control method and a traffic signal control device for preferential passing of special vehicles, wherein the method comprises the following steps: acquiring a path to be traveled of a special vehicle, and determining a plurality of intersections to be controlled by execution signals according to the path to be traveled; acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data; determining signal green wave control information of an intersection of the special vehicle within a preset distance ahead along the current position in the path to be driven based on the average driving speed and a preset time threshold; after the special vehicle passes through the crossing to be subjected to signal control, corresponding traffic control signal recovery is carried out on signal green wave control information corresponding to the passing crossing until the original timing of the passing crossing is recovered. The invention can ensure the prior passing of special vehicles, and can utilize the signal to recover after passing, thereby reducing the influence on social traffic.
Description
Technical Field
The invention relates to the technical field of traffic signal control, in particular to a traffic signal control method and device for preferential passing of special vehicles.
Background
During large-scale activities, special vehicles such as service vehicles and service support vehicles enjoy priority right of way in the road network around the activity venue. Spatially, priority is often given to such special vehicles by laying out a dedicated lane. In addition, the traffic signal lamp, which is an important component of an urban road, plays a decisive role in successfully realizing the priority traffic of such special vehicles, and therefore, the traffic signal lamp is required to provide traffic guarantee for the special vehicles when being combined with signal timing.
At present, the existing research related to the prior passage of special vehicles mainly includes public transportation priority and emergency vehicle priority. The bus has the characteristics of fixed route, timed departure and the like, and can pass preferentially by means of prolonging the green light, early breaking the red light, adding a special phase and the like. Emergency vehicles (ambulances, fire trucks, etc.) have a higher priority, so the need to ensure their smooth passage is more pronounced in such problems, with priority traffic measures close to mandatory priority, and other social vehicles need to give way to emergency vehicles as much as possible. The special vehicles mentioned above have no definite departure times and routes like buses during large activities, nor have absolute priority right of way like emergency vehicles. At this time, it is necessary to develop a real-time signal control and recovery scheme that takes priority right of passage of special vehicles and influence on social vehicles into consideration.
Disclosure of Invention
The invention provides a traffic signal control method and a traffic signal control device for preferential passing of special vehicles, which are used for solving the problems.
The invention provides a traffic signal control method for preferential passing of special vehicles, which comprises the following steps:
acquiring a path to be traveled of a special vehicle, and determining a plurality of intersections to be controlled by execution signals according to the path to be traveled;
acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data;
determining signal green wave control information of an intersection which is within a preset distance ahead along the current position in a path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold;
and after the special vehicle passes through the intersection to be subjected to signal control, carrying out corresponding traffic control signal recovery on signal green wave control information corresponding to the passing intersection until the original timing of the passing intersection is recovered.
According to the traffic signal control method for the preferential passage of the special vehicle, provided by the invention, the position data of the special vehicle in the running process is acquired in real time, and calculating an average traveling speed of the special vehicle in a predetermined time period ahead of the present time based on the position data, including:
acquiring position data of a special vehicle at the starting moment of a preset time period as first position data;
acquiring position data of the special vehicle at the end time of the preset time period as second position data;
and determining the average running speed in the preset time period according to the path distance between the first position data and the second position data and the preset time period.
According to the traffic signal control method for the preferential passage of the special vehicle, provided by the invention, the preset time period is a preset number of sampling periods, and the sampling periods are time periods for acquiring the position data of the special vehicle in the running process in real time.
According to the traffic signal control method for preferential passage of the special vehicle, provided by the invention, the signal green wave control information of the intersection, which is within the preset distance ahead of the current position in the path to be traveled, of the special vehicle is determined based on the average traveling speed of the special vehicle and the preset time threshold, and the method comprises the following steps:
determining a priority phase of the current intersection based on the path to be traveled; wherein the current intersection is one of the intersections within the forward preset distance;
acquiring the phase information of the priority phase and the signal period of the current intersection; the phase information comprises a phase difference, a red light duration and a green light duration;
determining the queuing forming and dissipating speed of vehicles based on the traffic flow and density of the priority phase;
predicting the time of the special vehicle reaching the current intersection according to the average running speed of the special vehicle and the distance between the current position and the current intersection;
and adjusting the green light starting time and the green light ending time of the priority phase according to the predicted arrival time, the phase information, the speed of vehicle queue formation and dissipation and the signal period, so that the predicted arrival time is within a time period between the green light starting time and the green light ending time of the priority phase, and the vehicle queue is emptied before the time period starts.
According to the traffic signal control method for preferential passage of special vehicles, provided by the invention, the green light starting time and the green light ending time of the preferential phase are adjusted according to the predicted arrival time, the phase information, the vehicle queuing forming and dissipating time and the signal period, and the traffic signal control method comprises the following steps:
determining the adjusted red light time length according to the upper red light time length boundary and the lower red light time length boundary which need to be met by the adjusted red light time length;
determining the green light starting time of the priority phase according to the adjusted red light duration;
determining the adjusted green light time length based on the green light time length before adjustment and the minimum green light time length which can ensure that a special vehicle can preferentially pass and is obtained according to the predicted arrival time, the preset time insurance, the phase difference, the red light time length before adjustment, the adjusted red light time length and the signal period;
and determining the end time of the green light according to the adjusted green light duration and the green light starting time.
According to the traffic signal control method for the priority passing of the special vehicle, the time for queuing and dissipating the vehicle is determined based on the traffic flow and the density of the priority phase, and the method comprises the following steps:
obtaining vehicle queuing forming speed omega based on traffic flow and density of priority phase f And dissipation velocity ω s ：
In the formula, q arrive For traffic flow of vehicles to an intersection, q queue Traffic flow, q, for vehicles queuing ahead of the intersection leave For traffic flow of vehicles leaving the intersection, k arrive For the traffic flow density, k, of vehicles arriving at the intersection queue Traffic flow density, k, for queuing vehicles in front of the intersection leave Is the traffic flow density of the vehicles driving away from the intersection.
According to the traffic signal control method for preferential passage of special vehicles provided by the invention, the upper limit and the lower limit of the red light time length required to be met by the adjusted red light time length are determined in the following way:
determining the speed v of the vehicle driving away from the intersection according to the traffic flow of the vehicle driving away from the intersection and the traffic flow density of the vehicle driving away from the intersection leave ：
In the formula, q leave For traffic flow of vehicles leaving the intersection, k leave The traffic flow density of the vehicles driving away from the intersection;
based on the speed v of said vehicle leaving the intersection leave Vehicle queuing forming speed omega f And dissipation velocity omega s Obtaining the adjusted red light time length r i Time t of emptying queue with vehicle clear The relationship between:
in the formula, v leave Is the speed at which the vehicle is driven off the intersection,
to queue the time required for the formation wave to meet the evanescent wave,
the time required for the queue length to dissipate from maximum;
according to said phase difference f i The time length r of the red light before adjustment i Time t for queuing and emptying of vehicles clear Signal period C i And acquiring a time interval corresponding to the predicted arrival time when the special vehicle does not need to queue to pass through the current intersection by the preset time insurance tau:
t i ≥f i -r i +r′ i +t clear +nC i +τ
in the formula, n is a non-negative integer;
according to the adjusted red light time length r' i Time t of queuing up with vehicle clear The relation and the time interval between the red light and the red light obtain the upper bound of the red light duration
According to the adjusted red light time length r' i Not less than the phase set corresponding to the current intersection i
Except for the priority phase
The minimum green time period of all other phases than the minimum green time period of the red light, thereby determining a lower bound of the red light time period i r′：
In the formula, g p，min Indicating the minimum green time duration for phase p,
indicating that phase p belongs to the set of phases
But not the preferred phase
According to the traffic signal control method for preferential passage of special vehicles provided by the invention, the adjusted red light time length is determined according to the upper limit and the lower limit of the red light time length which need to be met by the adjusted red light time length, and the method comprises the following steps:
lower bound on duration of red light i r′Greater than red light duration upper bound
In the case of (2), lower bound is the red light duration i r′As the adjusted red light duration;
lower bound on duration of red light i r′Not greater than red light time length upper bound
In the case of (1), judgment is made
Whether or not greater than
In that
Not more than
Under the condition of (1), calculating to obtain the adjusted red light time length r 'according to the red light time length lower bound, the minimum green light time length corresponding to the phase P and the green light time length of the phase P before adjustment' i ：
In the formula (I), the compound is shown in the specification, i r′the lower bound of the duration of the red light, g p，min For the minimum green duration, g, corresponding to phase p p The green duration of the phase P before adjustment;
in that
Is greater than
In the case of (2), the red light duration is upper bound
As adjusted red light time period r' i 。
According to the traffic signal control method for preferential passing of special vehicles, provided by the invention, the red light duration is limited to the lower bound i r′After the adjusted red light duration, the method further comprises:
judging whether a special lane is arranged on the path to be traveled or not;
under the condition of arranging a special lane, calculating the delay d of the special vehicle at the current intersection i through the red light time length lower bound and the red light time length upper bound i ：
In the formula (I), the compound is shown in the specification, i r′is the lower bound of the time length of the red light,
the upper limit of the red light duration is set;
updating the predicted arrival time of the new next intersection i' based on the delay and the predicted arrival time of the next intersection i
In the formula, d i For delay, t i′ The predicted arrival time of the next intersection i'.
According to the traffic signal control method for preferential passing of special vehicles, provided by the invention, the red light duration is limited to the lower bound i r′After the adjusted red light duration, the method further comprises:
according to the time length lower bound of the red light under the condition that no special lane is arranged i r′Average running speed of special vehicle
Distance S between current position of special vehicle and current intersection on driving path i And the current time t of the special vehicle j Calculating the delay d of a special vehicle at the current intersection i i ：
d i ＝ i r′-π 1 +π 2
ω f π 1 ＝ω s π 2
π 3 -π 1 ＝f i -r i +n′C i -t j
In the formula, pi 1 The time length of the time between the red light starting time of the current intersection i and the time when the special vehicle starts to queue is pi 2 For the length of time, pi, between the current moment of collecting position data and the moment when a particular vehicle starts to queue 3 N' is a nonnegative integer and is the time length between the red light ending time of the current intersection i and the time when the special vehicle leaves the vehicle team;
updating the predicted arrival time of the new next intersection i' based on the delay and the predicted arrival time of the next intersection i
In the formula (d) i For delay, t i′ The predicted arrival time of the next intersection i'.
According to the traffic signal control method for preferential passing of special vehicles, provided by the invention, the red light duration is limited
As adjusted red light time period r' i Thereafter, the method further comprises:
calculating the green light time length g 'of the adjusted phase P according to the red light time length upper bound and the green light time length of the phase P before adjustment' p ：
In the formula (I), the compound is shown in the specification,
upper bound of red light duration, g p The green duration for phase P before the adjustment.
According to the traffic signal control method for the special vehicle to pass preferentially provided by the invention, after the special vehicle passes through the crossing, the corresponding traffic control signal recovery is carried out on the crossing which passes through based on the signal green wave control information of the crossing until the original timing of the crossing which passes through is recovered, the method comprises the following steps:
under the condition that the control mode of the traffic control signal is single-point control, the lower bound C according to the signal period min And upper bound C max Determining a new signal period C by enumerating signal periods by a predetermined separation distance new The new signal period C new Can minimize the traffic delay of the current intersection and according to the new signal period C new Obtaining the new green light duration of each phase of the current intersection
C min ≤C new ≤C max
In the formula (I), the compound is shown in the specification,
set of all phases for the current intersection i, phase
yp is the maximum traffic flow saturation of each lane combination corresponding to the phase p, lambda p Green ratio of phase p, q p，max Maximum vehicle arrival rate for each lane combination corresponding to phase p, s represents traffic flow saturation flow rate, g p，min Minimum green duration, C, representing a set phase p in the signalling system min 、 C max Respectively represent the lower and upper bounds, g ', of the signal period' p Green duration, g, for adjusted phase p p To adjust the green duration of the front phase p.
According to the traffic signal control method for the special vehicle to pass preferentially provided by the invention, after the special vehicle passes through the crossing, the corresponding traffic control signal recovery is carried out on the crossing which passes through based on the signal green wave control information of the crossing until the original timing of the crossing which passes through is recovered, the method comprises the following steps:
under the condition that the control mode of the traffic control signal is the control of the main road coordination signal, the minimum positive integer N and the corresponding new green light time length of each phase of the current intersection are determined
To meet the minimum green light duration requirement:
min N
s.t.C new ＝NC-(r′ i +g′ i )
C new ＞0
C min ≤C new ≤C max
in the formula, C new Is a new signal period, C is an original signal period, r' i ，g′ j The adjusted red light duration and green light duration, g p To adjust the green duration, g ', of the front phase p' p Green duration, g, for adjusted phase p p，min The minimum green light duration corresponding to the phase p; c min 、 C max Representing the lower and upper bounds of the signal period.
The present invention also provides a traffic signal control apparatus for preferential passage of a special vehicle, comprising:
the intersection determining module is used for acquiring a path to be traveled of a special vehicle and determining a plurality of intersections to be controlled by the execution signal according to the path to be traveled;
the speed calculation module is used for acquiring position data of the special vehicle in the running process in real time and calculating the average running speed of the special vehicle in a previous preset time period at the current moment based on the position data;
the green wave control information determining module is used for determining signal green wave control information of an intersection which is within a preset distance ahead along the current position in a path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold;
and the signal recovery module is used for performing corresponding traffic control signal recovery on the signal green wave control information corresponding to the passing intersection after the special vehicle passes through the intersection to be subjected to signal control until the original timing of the passing intersection is recovered.
The invention also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein when the processor executes the program, the method for controlling the traffic signal for the preferential passage of the special vehicle is realized.
The present invention also provides a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements any of the above-described traffic signal control methods for priority passage of a particular vehicle.
The traffic signal control method and the traffic signal control device for preferential passage of the special vehicle determine the signal green wave control information of the intersection within the preset distance ahead along the current position in the path to be traveled by the special vehicle based on the average traveling speed of the special vehicle and the preset time threshold, provide green waves for a plurality of intersections ahead by adjusting the signal timing of the intersections ahead of the special vehicle in real time, form rolling green waves, can empty social queuing vehicles in advance, ensure that the special vehicle can smoothly pass at the predicted time of reaching the intersection, and reduce the influence on the society traffic after the special vehicle passes through by performing corresponding traffic control signal recovery on the signal green wave control information of the intersection.
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In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a schematic flow chart of a traffic signal control method for preferential passage of a special vehicle according to an embodiment of the present invention;
FIG. 2 is a schematic illustration of the effect of a rolling green wave on road operation provided by an embodiment of the present invention;
fig. 3 is a vehicle operation space-time diagram of a priority phase corresponding to a current intersection i according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of the delay of a special vehicle without a dedicated lane according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating an embodiment of a scenario for recovering a signal at a road junction in accordance with the present invention;
FIG. 6 is a schematic structural diagram of a traffic signal control device for priority traffic of a specific vehicle according to an embodiment of the present invention;
fig. 7 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Before the traffic signal control method and the traffic signal control device for preferential passage of special vehicles are realized, the following preparation work needs to be completed:
(1) The special vehicle is provided with a GPS acquisition device, so that the information such as the position, the speed and the like of the vehicle can be acquired in real time conveniently; wherein, the time interval of data acquisition does not exceed 10 seconds, and the positioning accuracy is not lower than 15 meters.
(2) And each intersection in a road network on which special vehicles travel is networked, so that the central control system can receive instructions in real time to adjust the signal timing of each intersection. Particularly, if a certain intersection cannot be networked due to a fault or the like, and the front and rear intersections are in a normal networking state, the rolling green wave control can be respectively implemented on the paths in front of and behind the intersection by taking the intersection as a boundary.
(3) The traffic signal central control system allows real-time adjustment of the green light duration of each phase at each intersection without adjusting phase combinations, phase sequences and phase differences.
(4) Historical data corresponding to each intersection in the road network is obtained, and information such as traffic flow saturation, average queuing density and saturated traffic flow rate of each intersection can be obtained based on the historical data.
The traffic signal control method and device for preferential passage of special vehicles according to the present invention will be specifically described with reference to the drawings.
FIG. 1 is a schematic flow chart of a traffic signal control method for preferential passage of a special vehicle according to an embodiment of the present invention; as shown in fig. 1, a traffic signal control method for preferential passage of a special vehicle includes the steps of:
s101, obtaining a path to be traveled of a special vehicle, and determining multiple intersections to be controlled by signals according to the path to be traveled.
In general, the destination and route of a special vehicle such as a service vehicle or a service vehicle are determined, so that before traffic signal control, a corresponding travel route, i.e., a route to be traveled, can be obtained, and a plurality of intersections to be subjected to signal control and phases corresponding to the intersections are determined on the route to be traveled by the following principle:
(1) If the special vehicle needs to drive at a crossing (turn left, go straight or turn right), the crossing is controlled by the traffic signal, the crossing is the crossing controlled by the signal to be executed, and the priority phase of the signal control is consistent with the phase of the special vehicle driving action, namely the phase corresponding to the crossing controlled by the signal to be executed;
(2) If the driving action of a special vehicle which needs to be carried out at a certain intersection is not controlled by a traffic signal at the intersection (normally, the right turn is not controlled by a signal lamp), the signal priority is not required to be carried out at the intersection, and the intersection is the common intersection.
S102, acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data.
In this step, the position data of the special vehicle during the driving process is obtained in real time through the GPS acquisition device equipped on the aforementioned special vehicle, and the average driving speed of the special vehicle in a period of time before the current time is calculated according to the position data and the time interval of data sampling.
S103, signal green wave control information of an intersection, which is within a preset distance from the current position of the special vehicle along the path to be traveled, is determined based on the average traveling speed and the preset time threshold, and the preset distance is determined according to the average traveling speed and the preset time threshold.
After the average driving speed of the special vehicle is obtained, the time when the special vehicle reaches the nearest intersection controlled by the signal to be executed is predicted according to the driving path distance (nonlinear distance) between the current position of the special vehicle and the nearest intersection controlled by the signal to be executed, the signal green wave control information corresponding to the intersection controlled by the signal to be executed is obtained according to the predicted arrival time, and the signal corresponding to the intersection controlled by the signal to be executed is controlled according to the signal green wave control information, so that the social vehicle at the intersection is emptied before the special vehicle reaches the intersection controlled by the signal to be executed, and the priority traffic of the vehicle is guaranteed.
It should be noted that, the intersection within the preset distance from the current position to the front is the nearest intersection to be controlled by the execution signal, and the preset distance has a maximum distance threshold, which is determined according to the average driving speed and the preset time threshold, that is, if the preset distance exceeds the distance threshold, the signal control on the nearest intersection to be controlled by the execution signal will be greatly affected; if the preset distance does not exceed the distance threshold, the signal control cannot cause excessive influence on other intersections in front.
Specifically, since the present invention uses a rolling green wave, that is, as shown in fig. 2, the front of a particular vehicle is adjusted in real time as the particular vehicle advancesThe signal timing of a plurality of intersections provides green waves for the intersections, so that the signal green waves and special vehicles can synchronously advance in a road network. Therefore, it is necessary to determine the number of intersections included in the rolling green wave, that is, how many intersections ahead of the current position of the vehicle need to be provided with the signal green wave. The setting of the signal green wave also needs to meet certain conditions, and if the intersection needing to set the signal green wave is too close to the current position of the special vehicle, the signal green wave will have an excessive influence on a plurality of intersections in front. Therefore, a distance threshold is set for the preset distance, i.e. the distance between the current vehicle position and the ith intersection on the driving path
Wherein T is a preset time threshold value,
time difference delta t between the current time and the j-m sampling time for a special vehicle j,j-m The average running speed within.
The main considerations for setting the time threshold T include: firstly, the accuracy of the prediction of the arrival time of the special vehicle is higher in the T time after the current time; secondly, forward to the current position of the special vehicle
The signal timing modification at the intersection within the distance (namely the preset distance) does not cause great influence on the front intersection. In practical applications, T =40-60 seconds may be taken, and an optimal T value may be determined through multiple tests, which is not limited by the present invention.
In addition, the signal green wave control mentioned above is rolling signal green wave, that is, as the special vehicle runs in the road network, the signal timing of a plurality of intersections in front of the vehicle is dynamically adjusted to provide green wave for the special vehicle, so that the signal green wave and the special vehicle synchronously advance in the road network, that is, the special vehicle can realize preferential passing at each intersection.
And S104, after the special vehicle passes through the intersection controlled by the signal to be executed, carrying out corresponding traffic control signal recovery on signal green wave control information corresponding to the passing intersection until the original timing of the passing intersection is recovered.
In this step, after the special vehicle passes through the intersection to be subjected to signal control, if no next special vehicle needs to pass through, a proper signal recovery scheme needs to be executed for the passing intersection until the original timing of the intersection is recovered, so as to reduce the influence brought by ensuring the special vehicle to pass through as much as possible.
The signal recovery schemes are divided into two types according to different traffic signal control modes adopted by passing intersections, wherein one type is the signal recovery scheme of a single-point control intersection, and the other type is the signal recovery scheme of a main road coordination intersection. The signal recovery scheme of the single-point control intersection aims to recover the original signal scheme as soon as possible and provide green light compensation for the direction with larger loss as far as possible; and the signal recovery scheme of the main road coordination intersection is to recover the intersection to the main road coordination state as early as possible. The above two signal recovery schemes are described in detail below.
The traffic signal control method for the preferential passage of the special vehicle determines the signal green wave control information of the intersection within the preset distance ahead along the current position in the path to be traveled by the special vehicle based on the average traveling speed and the preset time threshold of the special vehicle, provides green waves for a plurality of intersections ahead by adjusting the signal timing of the intersections ahead of the special vehicle in real time, forms rolling green waves, can empty social queuing vehicles in advance, ensures that the special vehicle can smoothly pass at the predicted time of reaching the intersection, and reduces the influence of the special vehicle on social traffic after passing through by carrying out corresponding traffic control signal recovery on the signal green wave control information of the intersection.
Further, since the GPS collection device has a fixed sampling time interval at the time of data collection, the average traveling speed of the special vehicle can be calculated from the sampling time, the position of the special vehicle at the sampling time, and the current position of the special vehicle.
Specifically, the obtaining of the position data of the special vehicle in the running process in real time and the calculating of the average running speed of the special vehicle in a predetermined time period before the current time based on the position data includes:
the method comprises the steps of acquiring position data of a special vehicle at the starting moment of a preset time period (namely the current moment of the special vehicle) as first position data, namely, determining the position in a period of time before the current moment according to collected historical position data and sampling time intervals, namely, determining the position as a first position. It should be noted that the predetermined time period before the current time is a time point after a period of time after the current time is reversed, where the period of time is the predetermined time period.
The path to be traveled of the special vehicle and the sampling time interval of the position data are used for acquiring the position of the special vehicle in a future period (namely a preset time period) from the current moment
And acquiring the position data of the special vehicle at the ending time (namely the current time) of the preset time period as second position data, wherein the second position at the moment is the current position of the special vehicle.
And determining the average running speed in the preset time period according to the path distance between the first position data and the second position data and the preset time period.
Wherein a path distance between the first position data and the second position data is a driving path, not a straight path. The average velocity is calculated by:
in the formula,. DELTA.L j,j-m Represents the path distance, Δ t, between the current vehicle position (i.e., the second position) and the vehicle position (i.e., the first position) at the j-m sample time j,j-m Representing the time difference between the current time instant, i.e. the jth sample time instant, and the jth-m sample time instants, representing the jth-m sample time instant and the jth sample time instantThe time difference is m sampling time intervals, namely the preset time period.
Further, the predetermined time period is a predetermined number of sampling periods, that is, the predetermined time period is formed by m sampling time intervals, and the sampling period is a time period for acquiring the position data during the driving process of the special vehicle in real time, that is, a sampling time interval of the position data.
Further, the determining the signal green wave control information of the intersection within the preset distance ahead of the current position in the path to be traveled by the special vehicle based on the average traveling speed and the preset time threshold includes:
determining a priority phase of the current intersection based on the path to be traveled; and the current intersection is one of the intersections within the forward preset distance.
Specifically, if the intersection i needs to set the rolling green wave at the current time, the signal timing of the intersection needs to be adjusted in advance, so that the special vehicle can pass through the intersection without stopping when reaching the intersection. Correspondingly, the priority phase is recorded as
Acquiring the phase information of the priority phase and the signal period of the current intersection; the phase information includes a phase difference, a red light duration, and a green light duration.
Fig. 3 is a time-space diagram of vehicle operation of a priority phase corresponding to a current intersection i according to an embodiment of the present invention; as shown in fig. 3, the phase information corresponding to the current intersection i includes the phase difference f of the intersection i i Namely the time difference between the green light starting time of the current phase and the reference time zero point O; signal period C of current intersection i i (ii) a Red light duration r of current phase i Duration g of green light of current phase i 。
It should be noted that, in this embodiment, the yellow light and the full red time are not indicated, and they may be equivalent to the red light duration.
And determining the queuing forming and dissipating speed of the vehicles based on the traffic flow and the density of the priority phase, namely obtaining information such as traffic flow saturation, average queuing density, saturated traffic flow rate and the like through historical data of the intersection i, and further calculating to obtain the queuing forming and dissipating speed of the social vehicles at the intersection i for adjusting the signal timing of the intersection i so as to clear the social vehicles when the special vehicles reach the intersection i.
And predicting the time for the special vehicle to reach the current intersection according to the average running speed of the special vehicle and the distance between the current position and the current intersection.
Specifically, after the average traveling speed of the special vehicle is calculated as described above, the average traveling speed is calculated based on the average traveling speed
Current time t j The distance S between the current vehicle position and each intersection i to be controlled by the execution signal on the driving path i Predicting the predicted time t of the special vehicle to reach the ith intersection i ：
The predicted arrival time is a predicted arrival time when the special vehicle arrives at each intersection on the route under a normal driving condition (i.e., the special vehicle smoothly passes through the intersection without stopping or delaying), and if stopping or delaying occurs, the predicted arrival time is adjusted in real time.
And adjusting the green light starting time and the green light ending time of the priority phase according to the predicted arrival time, the phase information, the speed of vehicle queue formation and dissipation and the signal period, so that the predicted arrival time is within a time period between the green light starting time and the green light ending time of the priority phase, and the vehicle queue is emptied before the time period starts. That is, the time of arrival t is predicted i Can be between the green light starting time and the green light ending time and at the predicted arrival time t i Formerly, social vehicle root at intersection iEmptying is achieved according to the speed of vehicle queue formation and dissipation.
It should be noted that, one of the time periods within the time period between the green light start time and the green light end time of the priority phase of the predicted arrival time means that, for the phase of the current intersection i, in the green light period, there is a time period T i (see fig. 3) so that a particular vehicle arriving at intersection i can pass through the intersection without queuing.
The traffic signal control method for the preferential passage of the special vehicle determines the time required for emptying social vehicles according to the vehicle queuing forming and dissipating speed calculated according to the historical traffic flow data of the intersection i, and adjusts the original signal timing of the intersection i according to the predicted arrival time, the phase information and the signal period corresponding to the intersection i, namely the duration of a green light and a red light, so that the predicted arrival time t is t i Can be between the green light starting time and the green light ending time and is ensured to arrive at the predicted time t i In the past, the social vehicles at the intersection i are emptied according to the speed of formation and dissipation of vehicle queuing, so that the preferential passing of special vehicles is realized.
Further, the adjusting the green light start time and the green light end time of the priority phase according to the predicted arrival time, the phase information, the vehicle queue forming and dissipating time and the signal period comprises:
and determining the adjusted red light duration according to the upper red light duration boundary and the lower red light duration boundary which need to be met by the adjusted red light duration.
In this embodiment, when the green light start time corresponding to the intersection i needs to be determined, the adjusted red light duration needs to be determined first, and the adjusted red light duration has a value interval, which is composed of an upper red light duration boundary and a lower red light duration boundary, and is described in detail below.
And determining the green light starting time of the priority phase according to the adjusted red light duration.
After the adjusted red light duration is determined, the priority phase can be determined
Green light start time.
According to the predicted arrival time t i A predetermined time margin tau, a phase difference f i The time length r of the red light before adjustment i And the adjusted red light time length r' i And a signal period C i Obtaining the minimum green light time length which can ensure that a special vehicle can pass preferentially; and determining the adjusted green light time length by comparing the magnitude relation between the green light time length before adjustment and the minimum green light time length.
In particular, in determining the priority phase
After the green light start time of (2), the priority phase can be obtained according to the following formula
Corresponding adjusted green light duration g' i 。
g′ i ＝max(g i ，ti+τ-f i +r i -r′ i -nC i )
Wherein n is a non-negative integer, i.e. the duration of green light required to ensure preferential passage of a particular vehicle does not exceed the phase
Original green light duration g i In case of (2), g' i Duration g of green light i That is, when g i ≥t i +τ-f i +r i -r i -nC i G' i ＝g i (ii) a When g is i ＜t i +τ-f i +r i -r i -nC i When it is, then g i ＝t i +τ-f i +r i - r′ i -nC i I.e. green light duration g i The green light time required for ensuring the preferential passing of the special vehicle.
According to the adjustedDetermining the green light end time by the green light time length and the green light start time, namely, on the basis of the green light start time, using the adjusted green light time length g i The green light end time is determined.
According to the traffic signal control method for preferential passage of special vehicles, provided by the embodiment of the invention, the adjusted start time and end time of the green light are determined according to the predicted time and the phase information corresponding to the current intersection i, so that green wave rolling is realized, and the preferential passage of the special vehicles is ensured.
Further, the time for forming and dissipating vehicle queues is determined based on the traffic flow and the density of the priority phase, and comprises the following steps:
obtaining vehicle queuing forming speed omega based on traffic flow and density of priority phase f And dissipation velocity ω s ：
In the formula, q arrive For traffic flow of vehicles to an intersection, q queue Traffic flow, q, for vehicles queuing ahead of the intersection leave For traffic flow of vehicles leaving the intersection, k arrive Density of traffic flow, k, for vehicles arriving at the intersection queue Traffic flow density, k, for vehicles queuing ahead of the intersection leave Is the traffic flow density of the vehicles driving away from the intersection.
The traffic flow rate and the density are both obtained from the historical traffic flow data at the intersection i.
Further, the red light time length upper bound and the red light time length lower bound that the adjusted red light time length needs to satisfy are determined by the following method:
according to the traffic flow of the vehicle driving away from the intersection and the traffic of the vehicle driving away from the intersectionDetermining speed v of vehicle driving away from intersection by current density leave ：
In the formula, q leave For traffic flow of vehicles leaving the intersection, k leave Is the traffic flow density of the vehicles driving away from the intersection.
Based on the speed v of said vehicle leaving the intersection leave Vehicle queuing forming speed omega f And dissipation velocity omega s Obtaining the adjusted red light time length r i Time t of queuing up with vehicle clear The relationship between:
in the formula, v leave Is the speed at which the vehicle is driven off the intersection,
to queue the time required for the formation wave to meet the evanescent wave,
the time required for the queue length to dissipate from maximum.
According to the phase difference f i And the red light duration r before adjustment i Time t for queuing and emptying of vehicles clear Signal period C i And acquiring a time interval corresponding to the predicted arrival time when the special vehicle does not need to queue to pass through the current intersection by the preset time insurance tau:
t i ≥f i -r i +r′ i +t clear +nC i +τ
wherein n is a non-negative integer.
The time insurance tau in the above equation can ensure that the special vehicle does not experience queuing when arriving at the intersection, so that the special vehicle arrives at the intersection as early as tau after the queuing is completely emptied. n is used for complementing the predicted arrival time t of the vehicle i Absolute time difference between signal timing at intersection i (i.e. signal period C) i Integer multiples of).
According to the adjusted red light time length r' i Time t of queuing up with vehicle clear The relation and the time interval between the red light and the red light obtain the upper bound of the red light duration
According to the adjusted red light time length r' i Not less than the phase set corresponding to the current intersection i
Except for the priority phase
The minimum green time period of all other phases than the minimum green time period of the red light, thereby determining a lower bound of the red light time period i r′：
In the formula, g p，min Indicating the minimum green time duration for phase p,
indicating that phase p belongs to the set of phases
But not the preferred phase
It should be noted that, in the traffic signal control system, there is often a limit of the minimum green time period, i.e., the adjusted green time period should not be less than the minimum green time period, i.e., the priority phase
The red light duration of the lamp is not less than the sum of the minimum green light durations of all the other phases, and the sum of the minimum green light durations of all the other phases is the adjusted red light duration r' i The lower bound of (c).
Further, the determining the adjusted red light duration according to the upper red light duration boundary and the lower red light duration boundary that the adjusted red light duration needs to meet includes:
lower bound on duration of red light i r′Greater than red light duration upper bound
In the case where a suitable one cannot be found, that is, in the case where a suitable one cannot be found i r′So that the red light duration is lower bound under the condition that special vehicles can smoothly pass through the intersection without queuing i r′As adjusted red light duration, i.e. removing priority phase of special vehicle traffic
Besides, all other phases of the intersection i use the minimum green light duration, and the priority phase is started in advance
To reduce the delay in the passage of a particular vehicle.
Lower bound on duration of red lightr′iNot greater than red light time length upper bound
In the case of (1), judgment is made
Whether or not greater than
In that
Not more thanUnder the condition that the intersection i does not need to change signal timing, the special vehicle can pass through without delay, the duration of green light of all the other phases is not changed, and the lower bound of the duration of red light can be realized at the moment i r′Minimum green time length g corresponding to phase p p，min And the green duration g of the phase P before adjustment p Calculating to obtain the adjusted red light time length r' i ：
In that
Is greater than
In the case of (1), the green duration of other phases needs to be shortened, and the phase is started in advance
So as to reduce the passing delay of special vehicles, at the moment, the duration of the red light can be limited
As adjusted red light time period r' i 。
Further, the lower bound on the duration of the red light due to the above i r′Greater than red light duration upper bound
In the case of (2), no suitable r 'can be found' i Therefore, special vehicles can smoothly pass through the intersection without queuing, delay occurs to the special vehicles, and the time of passing through the subsequent intersection can be changed due to the delay. Therefore, the lower bound of the red light duration i r′After the adjusted red light duration, the method further comprises:
and judging whether a special lane is arranged on the path to be traveled or not.
Under the condition of arranging a special lane, the time length lower bound of passing the red light i r′Upper bound of time length of red light
Calculating the delay di of the special vehicle at the current intersection i:
based on said delay d i And predicted arrival time t of the next intersection i i′ Updating the predicted arrival time of the new next intersection i
The traffic signal control method for the preferential passage of the special vehicle provided by the embodiment of the invention updates the prediction time by calculating the delay, and ensures that the special vehicle can pass preferentially at the subsequent intersection i.
Further, the lower bound of the duration of the red light i r′As the adjusted red light durationAfterwards, the method further comprises:
FIG. 4 is a schematic diagram of the delay of a special vehicle without a dedicated lane according to an embodiment of the present invention; as shown in fig. 4, in the case where no exclusive lane is provided, the lower bound is set according to the red light time periodr′iAverage running speed of special vehicle
Distance S between current position of special vehicle and current intersection on driving path i And the current time t of the special vehicle j Calculating the delay d of the special vehicle at the current intersection i i ：
d i ＝ i r′-π 1 +π 2
ω f π 1 ＝ω s π 2
π 3 -π 1 ＝f i -r i +n′C i -t j
In the formula, pi 1 The time length, pi, between the time when the red light of the current intersection i starts and the time when the special vehicle starts queuing 2 For the length of time, pi, between the current moment of collecting position data and the moment when a particular vehicle starts to queue 3 N' is a nonnegative integer and is the time length between the red light ending time of the current intersection i and the time when the special vehicle leaves the vehicle team;
based on said delay d i And predicted arrival time t of the next intersection i i′ Updating the predicted arrival time of the new next intersection i
The traffic signal control method for the preferential passage of the special vehicle provided by the embodiment of the invention updates the prediction time by calculating the delay, and further ensures that the special vehicle can pass preferentially at the subsequent intersection i.
Further, the red light duration is bounded above
As adjusted red light time period r' i In the case of (2), i.e. the duration of the green lamp for the other phases needs to be shortened, by turning on the priority phase in advance
Under the condition of reducing the traffic delay of special vehicles, the green light time lengths of the other phases corresponding to the intersection i need to be redistributed according to the traffic flow saturation of each phase, so that the adjusted green light time length g 'of the phase P is formed' p 。
Specifically, the red light duration is upper bound
As adjusted red light time period r' i Thereafter, the method further comprises:
according to the upper bound of the duration of the red light
And the green duration g of the phase P before adjustment p Calculating the green light time length g 'of the adjusted phase p' p ：
Further, after the special vehicle passes through the intersection, performing corresponding traffic control signal restoration on the passed intersection based on the signal green wave control information of the intersection until the original timing of the passed intersection is restored, including:
control at traffic control signalsIn the case of single-point control, the lower bound C is determined by the signal period min And upper bound C max Determining a new signal period C by enumerating signal periods by a predetermined separation distance new The new signal period C new Can minimize the traffic delay of the current intersection and according to the new signal period C new Obtaining the new green light time of each phase of the current intersection
C min ≤C new ≤C max
In the formula (I), the compound is shown in the specification,
is the set of all phases of the current intersection i, the phase
y p For maximum traffic saturation, λ, of each lane combination corresponding to phase p p Green ratio of phase p, q p，max Maximum vehicle arrival rate for each lane combination corresponding to phase p, s represents traffic flow saturation flow rate, g p，min Minimum green duration, C, representing a set phase p in the signalling system min 、 C max Respectively represent the lower and upper bounds, g ', of the signal period' p Green duration, g, for adjusted phase p p To adjust the green duration of the front phase p.
Specifically, at a single-point control signal intersection, a recovery period needs to be set, that is, a recovery scheme is executed in the next period after a special vehicle passes through, and then the original scheme is executed.
The setting method of the recovery scheme is to determine an optimal new period C new The traffic delay of the intersection in the new period is minimized. For any new cycle C new Determining the green duration of each phase in the cycle in proportion
This ratio depends on the traffic saturation of each phase (expressed as the green duration of each phase in the original signal scheme, according to y in the above equation p Obtained), the passing period of a particular vehicle (i.e., C in the above formula) new ) And green duration variation for each phase (i.e., in the above equation)
) The situation is.
For a certain phase
max(0，g p -g′ p ) Is expressed as the adjusted green light duration g 'if in the last period' p ≤g p When designing a recovery scheme, the missing green time needs to be compensated for phase p; otherwise, no compensation is required.
For any new period C new The corresponding total delay of the intersection can be directly calculated, so that the period can be enumerated at intervals of preset distance between the upper and lower bounds of the period, and an optimal period is selected from the periodsAnd the duration is obtained, and the corresponding green light duration of each phase is obtained.
According to the traffic signal control method for preferential passage of special vehicles, which is provided by the embodiment of the invention, the corresponding signal recovery scheme is designed aiming at the intersection controlled by a single point, so that the original signal scheme is recovered as soon as possible, green light compensation is given to the direction with larger loss as far as possible, and the influence on social vehicles is reduced.
Further, after the special vehicle passes through the intersection, performing corresponding traffic control signal restoration on the passed intersection based on the signal green wave control information of the intersection until the original timing of the passed intersection is restored, including:
under the condition that the control mode of the traffic control signal is the control of the main road coordination signal, the minimum positive integer N and the corresponding new green light time length of each phase of the current intersection are determined
To meet the minimum green light duration requirement:
min N
s.t.C new ＝NC-(r′ i +q′ i )
C new ＞0
C min ≤C new ≤C max
in the formula, C new Is a new signal period, C is an original signal period, r' i ，g′ i Respectively the adjusted red light time lengthDuration with green light, g p To adjust the green duration, g ', of the front phase p' p Green duration, g, for adjusted phase p p，min The minimum green light duration corresponding to the phase p; c min 、C max Representing the lower and upper bounds of the signal period.
Specifically, for intersections controlled using the main-road coordination signal, the goal of setting the recovery scheme is to recover to the coordination state as early as possible after the passage of a special vehicle. During the recovery process, NC- (r ') after the signal period of passing of the special vehicle is enabled by determining a positive integer N as small as possible' i +g′ i ) In time (C is an original period), the green light duration of each phase is adjusted according to the same method as that of the single-point control intersection, and meanwhile, the limit of the shortest green light duration is required to be met.
FIG. 5 is a diagram illustrating an embodiment of a scenario for recovering a signal at a road junction in accordance with the present invention; as shown in fig. 5, when the positive integer determined as small as possible is N =2, it is assumed that three phases are set in total at the intersection, and the third phase is used by the special vehicle. The signal period of passing of the special vehicle exceeds the original period due to the guarantee of the special vehicle, and the green light time of three phases is prolonged in the next period
According to
C new And calculating to obtain the result, and recovering to the trunk coordination state again according to the result.
According to the traffic signal control method for preferential passage of special vehicles, provided by the embodiment of the invention, the corresponding signal recovery scheme is designed for the intersection under the coordination control of the main road, so that the intersection is recovered to the main road coordination state as early as possible, and the influence on social vehicles is reduced.
The traffic signal control device for priority passage of special vehicles according to the present invention is described below, and the traffic signal control device for priority passage of special vehicles described below and the traffic signal control method for priority passage of special vehicles described above may be referred to in correspondence with each other.
Fig. 6 is a schematic structural diagram of a traffic signal control device for preferential passage of a special vehicle according to an embodiment of the present invention, and as shown in fig. 6, a traffic signal control device for preferential passage of a special vehicle includes:
the intersection determining module 601 is configured to obtain a path to be traveled by a special vehicle, and determine multiple intersections to be controlled by the execution signal according to the path to be traveled.
In general, the destination and route of a special vehicle such as a service vehicle or a service vehicle are determined, so that before traffic signal control, a corresponding travel route, i.e., a route to be traveled, can be obtained, and a plurality of intersections to be subjected to signal control and phases corresponding to the intersections are determined on the route to be traveled by the following principle:
(1) If the special vehicle needs to drive at a crossing (turn left, go straight or turn right), the crossing is controlled by the traffic signal, the crossing is the crossing controlled by the signal to be executed, and the priority phase of the signal control is consistent with the phase of the special vehicle driving action, namely the phase corresponding to the crossing controlled by the signal to be executed;
(2) If the driving action of a special vehicle which needs to be carried out at a certain intersection is not controlled by a traffic signal at the intersection (normally, the right turn is not controlled by a signal lamp), the signal priority is not required to be carried out at the intersection, and the intersection is the common intersection.
And the speed calculation module 602 is configured to obtain position data of the special vehicle in the running process in real time, and calculate an average running speed of the special vehicle in a previous predetermined time period at the current time based on the position data.
In the module, the position data of the special vehicle in the running process is acquired in real time through the GPS acquisition equipment equipped on the special vehicle, and the average running speed of the special vehicle is calculated according to the position data and the data sampling time.
A green wave control information determining module 603, configured to determine, based on the average driving speed and the predetermined time threshold, signal green wave control information of an intersection at which the special vehicle is within a preset distance ahead along the current position in the path to be driven, where the preset distance is determined according to the average driving speed and the predetermined time threshold.
After the average running speed of the special vehicle is obtained, the time when the special vehicle reaches the nearest intersection controlled by the signal to be executed is predicted according to the running path distance (non-linear distance) between the current position of the special vehicle and the nearest intersection controlled by the signal to be executed, signal green wave control information corresponding to the intersection controlled by the signal to be executed is obtained according to the predicted arrival time, the signal corresponding to the intersection controlled by the signal to be executed is controlled according to the signal green wave control information, and therefore the social vehicle at the intersection is emptied before the special vehicle reaches the intersection controlled by the signal to be executed, and the priority traffic of the vehicle is guaranteed.
It should be noted that, the intersection within the preset distance from the current position to the front is the nearest intersection to be controlled by the execution signal, and the preset distance has a maximum distance threshold, which is determined according to the average driving speed and the preset time threshold, that is, if the preset distance exceeds the distance threshold, the signal control on the nearest intersection to be controlled by the execution signal will be greatly affected; if the preset distance does not exceed the distance threshold, the signal control cannot cause excessive influence on other intersections in front.
Specifically, the invention uses the rolling green wave, namely, the green wave is provided for the special vehicle by adjusting the signal timing of a plurality of intersections in front of the special vehicle in real time along with the advance of the special vehicle, so that the signal green wave and the special vehicle can synchronously advance in a road network. Therefore, it is necessary to determine the number of intersections included in the rolling green wave, that is, how many intersections ahead of the current position of the vehicle need to be provided with the signal green wave. The setting of the signal green wave also needs to meet certain conditions, and if the intersection needing to set the signal green wave is too close to the current position of the special vehicle, the signal green wave will have an excessive influence on a plurality of intersections in front. Therefore, a distance threshold needs to be set for the preset distance, namely, the current vehicle position and the ith intersection are atDistance on the path of travel
Wherein T is a preset time threshold value,
time difference delta t between the current time and the j-m sampling time for a special vehicle j,j-m The average running speed within.
The main considerations for setting the time threshold T include: firstly, the accuracy of the prediction of the arrival time of the special vehicle is higher in the T time after the current time; secondly, forward to the current position of the special vehicle
The signal timing modification at the intersection within the distance (namely the preset distance) does not cause great influence on the front intersection. In practical operation, T =40-60 seconds may be taken, and an optimal T value may also be determined through multiple tests, which is not limited by the present invention.
In addition, the signal green wave control mentioned above is rolling signal green wave, that is, as the special vehicle runs in the road network, the signal timing of several intersections in front of the vehicle is dynamically adjusted to provide green wave for the special vehicle, so that the signal green wave and the special vehicle synchronously advance in the road network, that is, the special vehicle can realize priority passing at each intersection.
The signal recovery module 604 is configured to perform corresponding traffic control signal recovery on the signal green wave control information corresponding to the passing intersection after the special vehicle passes through the intersection to be subjected to signal control until the original timing of the passing intersection is recovered.
In this step, after the special vehicle passes through the intersection to be subjected to signal control, if no next special vehicle needs to pass through, a proper signal recovery scheme needs to be executed for the passing intersection until the original timing of the intersection is recovered, so as to reduce the influence brought by ensuring the special vehicle to pass through as much as possible.
The signal recovery schemes are divided into two types according to different traffic signal control modes adopted by passing intersections, wherein one type is the signal recovery scheme of a single-point control intersection, and the other type is the signal recovery scheme of a main road coordination intersection. The signal recovery scheme of the single-point control intersection aims to recover the original signal scheme as soon as possible and provide green light compensation for the direction with larger loss as far as possible; and the signal recovery scheme of the main road coordination intersection is to recover the intersection to the main road coordination state as early as possible.
According to the traffic signal control device for preferential passage of the special vehicle, signal green wave control information of intersections within a preset distance ahead along the current position in a path to be traveled of the special vehicle is determined based on the average traveling speed of the special vehicle and the preset time threshold, green waves are provided for a plurality of intersections ahead by adjusting the signal timing of the intersections ahead of the special vehicle in real time, rolling green waves are formed, social queuing vehicles can be cleared in advance, the special vehicle can pass at the predicted time of reaching the intersections, and the influence of the special vehicle on social traffic after passing is reduced by performing corresponding traffic control signal recovery on the signal green wave control information of the intersections.
Fig. 7 is a schematic entity structure diagram of an electronic device according to an embodiment of the present invention, and as shown in fig. 7, the electronic device may include: a processor (processor) 710, a communication Interface (Communications Interface) 720, a memory (memory) 730, and a communication bus 740, wherein the processor 710, the communication Interface 720, and the memory 730 communicate with each other via the communication bus 740. Processor 710 may invoke logic instructions in memory 730 to perform a traffic signal control method for priority passage of a particular vehicle, comprising: acquiring a path to be traveled of a special vehicle, and determining a plurality of intersections to be controlled by execution signals according to the path to be traveled; acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data; determining signal green wave control information of an intersection which is within a preset distance ahead along the current position in a path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold; and after the special vehicle passes through the intersection to be subjected to signal control, carrying out corresponding traffic control signal recovery on signal green wave control information corresponding to the passing intersection until the original timing of the intersection is recovered.
In addition, the logic instructions in the memory 730 can be implemented in the form of software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In still another aspect, the present invention also provides a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a traffic signal control method for preferential passage of a special vehicle provided by performing the above method, the traffic signal control method for preferential passage of a special vehicle comprising: acquiring a path to be traveled of a special vehicle, and determining a plurality of intersections to be controlled by execution signals according to the path to be traveled; acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data; determining signal green wave control information of an intersection within a preset distance ahead along the current position in the path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold; and after the special vehicle passes through the intersection controlled by the signal to be executed, carrying out corresponding traffic control signal recovery on signal green wave control information corresponding to the passing intersection until the original timing of the intersection is recovered.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment may be implemented by software plus a necessary general hardware platform, and may also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods of the various embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (16)
1. A traffic signal control method for preferential passage of a particular vehicle, comprising:
acquiring a path to be traveled of a special vehicle, and determining a plurality of intersections to be controlled by execution signals according to the path to be traveled;
acquiring position data of the special vehicle in the running process in real time, and calculating the average running speed of the special vehicle in a preset time period before the current moment based on the position data;
determining signal green wave control information of an intersection which is within a preset distance ahead along the current position in a path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold;
and after the special vehicle passes through the intersection to be subjected to signal control, carrying out corresponding traffic control signal recovery on signal green wave control information corresponding to the passing intersection until the original timing of the passing intersection is recovered.
2. The traffic signal control method according to claim 1, wherein the acquiring position data of the special vehicle during driving in real time and calculating an average driving speed of the special vehicle in a predetermined time period ahead of a current time based on the position data comprises:
acquiring position data of the special vehicle at the starting moment of a preset time period as first position data;
acquiring position data of the special vehicle at the end time of the preset time period as second position data;
and determining the average running speed in the preset time period according to the path distance between the first position data and the second position data and the preset time period.
3. The traffic signal control method according to claim 2, wherein the predetermined time period is a predetermined number of sampling periods, and the sampling period is a time period for acquiring position data during travel of the special vehicle in real time.
4. The traffic signal control method according to claim 1, wherein the determining signal green wave control information of the intersection within a preset distance ahead of the current position in the path to be traveled by the special vehicle based on the average traveling speed for a predetermined time threshold includes:
determining a priority phase of the current intersection based on the path to be traveled; wherein the current intersection is one of the intersections within the forward preset distance;
acquiring the phase information of the priority phase and the signal period of the current intersection; the phase information comprises a phase difference, red light duration and green light duration;
determining the queuing forming and dissipating speed of the vehicles based on the traffic flow and the density of the priority phase;
predicting the time of the special vehicle reaching the current intersection according to the average running speed of the special vehicle and the distance between the current position and the current intersection;
and adjusting the green light starting time and the green light ending time of the priority phase according to the predicted arrival time, the phase information, the speed of vehicle queue formation and dissipation and the signal period, so that the predicted arrival time is within a time period between the green light starting time and the green light ending time of the priority phase, and the vehicle queue is emptied before the time period starts.
5. The traffic signal control method of claim 4, wherein the adjusting the green light start time and the green light end time of the priority phase according to the predicted arrival time, the phase information, the time of vehicle queue formation and dissipation, and the signal period comprises:
determining the adjusted red light time length according to the upper red light time length boundary and the lower red light time length boundary which need to be met by the adjusted red light time length;
determining the green light starting time of the priority phase according to the adjusted red light duration;
obtaining the minimum green light time length capable of ensuring the preferential passing of the special vehicle according to the predicted arrival time, the preset time insurance, the phase difference, the red light time length before adjustment, the red light time length after adjustment and the signal period, and determining the green light time length after adjustment by comparing the magnitude relation between the green light time length before adjustment and the minimum green light time length;
and determining the end time of the green light according to the adjusted green light duration and the green light starting time.
6. The traffic signal control method of claim 4, wherein the determining of the time for queuing and dissipating vehicles based on the traffic flow and density of the priority phase comprises:
obtaining vehicle queuing forming speed omega based on traffic flow and density of priority phase f And dissipation velocity ω s ：
In the formula, q arrive For traffic flow of vehicles to an intersection, q queue Traffic flow, q, for vehicles queuing ahead of the intersection leave For traffic flow of vehicles leaving the intersection, k arrive Density of traffic flow, k, for vehicles arriving at the intersection queue Traffic flow density, k, for vehicles queuing ahead of the intersection leave Is the traffic flow density of vehicles driving off the intersection.
7. The traffic signal control method of claim 6, wherein the upper red light duration boundary and the lower red light duration boundary that the adjusted red light duration needs to meet are determined by:
determining the speed v of the vehicle driving away from the intersection according to the traffic flow of the vehicle driving away from the intersection and the traffic flow density of the vehicle driving away from the intersection leave ：
In the formula, q leave For traffic flow of vehicles leaving the intersection, k leave The traffic flow density of the vehicles driving away from the intersection;
based on the speed v of said vehicle leaving the intersection leave Vehicle queuing forming speed omega f And dissipation velocity omega s Obtaining the adjusted red light time length r i ' time t to clear queue with vehicle clear The relationship between:
in the formula, v leave Is the speed at which the vehicle is driven off the intersection,
to queue the time required for the formation wave to meet the evanescent wave,
the time required for the queue length to dissipate from maximum;
according to the phase difference f i When the red light before adjustmentLong r i Time t for queuing and emptying of vehicles clear Signal period C i And acquiring a time interval corresponding to the predicted arrival time when the special vehicle does not need to queue to pass through the current intersection by the preset time insurance tau:
t i ≥f i -r i +r′ i +t clear +nC i +τ
in the formula, n is a non-negative integer;
according to the adjusted red light time length r i ' time t to clear queue with vehicle clear The relation and the time interval between the red light and the red light get the upper bound of the red light duration
According to the adjusted red light time length r i ' not less than phase set corresponding to current intersection i
Except for the preferential phase
The minimum green time period of all other phases than the minimum green time period of the red light, thereby determining a lower bound of the red light time period i r′：
In the formula, g p,min Indicating the minimum green time duration for phase p,
indicating that phase p belongs to a set of phases
But not the preferred phase
8. The traffic signal control method of claim 7, wherein determining the adjusted red light duration according to the upper red light duration boundary and the lower red light duration boundary that the adjusted red light duration needs to meet comprises:
lower bound on duration of red light i r′Greater than red light duration upper bound
In the case of (2), lower bound on the red light time length i r′As the adjusted red light duration;
lower bound on duration of red light i r′Not greater than red light time length upper bound
In the case of (1), judgment is made
Whether or not greater than
In that
Not more than
Under the condition of (1), calculating to obtain the adjusted red light time length r 'according to the red light time length lower bound, the minimum green light time length corresponding to the phase P and the green light time length of the phase P before adjustment' i ：
In the formula (I), the compound is shown in the specification, i r′the lower bound of the duration of the red light, g p,min For the minimum green duration, g, corresponding to phase p p The green duration of the phase P before adjustment;
in that
Is greater than
In the case of (2), the red light duration is upper bound
As adjusted red light time period r' i 。
9. The traffic signal control method of claim 8, wherein the method is performed in a mobile communication system
The lower bound of the duration of the red light i r′After the adjusted red light duration, the method further comprises:
judging whether a special lane is arranged on the path to be traveled or not;
under the condition that a special lane is arranged, the delay d of the special vehicle at the current intersection i is calculated through the red light time length lower bound and the red light time length upper bound i ：
In the formula (I), the compound is shown in the specification, i r′is the lower bound of the time length of the red light,
the upper limit of the red light duration is set;
time update based on the delay and predicted arrival of the next intersection iGet the predicted arrival time of the new next intersection i
In the formula, d i For delay, t i′ The predicted arrival time of the next intersection i'.
10. The traffic signal control method of claim 8, wherein the red light is emitted for a lower bound of time i r′After the adjusted red light duration, the method further comprises:
according to the time length lower bound of the red light under the condition that no special lane is arranged i r′Average running speed of special vehicle
Distance S between current position of special vehicle and current intersection on driving path i And the current time t of the special vehicle j Calculating the delay d of the special vehicle at the current intersection i i ：
d i ＝ i r′-π 1 +π 2
ω f π 1 ＝ω s π 2
π 3 -π 1 ＝f i -r i +n′C i -t j
In the formula, pi 1 The time length, pi, between the time when the red light of the current intersection i starts and the time when the special vehicle starts queuing 2 For collecting the current time of position data and starting to arrange with special vehiclesThe length of time between moments of the team, pi 3 N' is a nonnegative integer and is the time length between the red light ending time of the current intersection i and the time when the special vehicle leaves the vehicle team;
updating the predicted arrival time of the new next intersection i' based on the delay and the predicted arrival time of the next intersection i
In the formula, d i For delay, t i′ The predicted arrival time of the next intersection i'.
11. The traffic signal control method of claim 8, wherein said red light is upper bounded in duration
As adjusted red light time period r' i Thereafter, the method further comprises:
calculating the green light time length g 'of the adjusted phase P according to the red light time length upper bound and the green light time length of the phase P before adjustment' p ：
In the formula (I), the compound is shown in the specification,
upper bound of red light duration, g p The green duration for phase P before the adjustment.
12. The traffic signal control method according to claim 1, wherein after the special vehicle passes through the intersection, performing corresponding traffic control signal recovery on the passed intersection based on the signal green wave control information on the intersection until the original timing of the passed intersection is recovered comprises:
under the condition that the control mode of the traffic control signal is single-point control, the lower bound C according to the signal period min And an upper bound C max Determining a new signal period C by enumerating signal periods by a predetermined separation distance new The new signal period C new Can minimize the traffic delay of the current intersection and according to the new signal period C new Obtaining the new green light time of each phase of the current intersection
C min ≤C new ≤C max
In the formula (I), the compound is shown in the specification,
is the set of all phases of the current intersection i, the phase
y p For maximum traffic saturation, λ, of each lane combination corresponding to phase p p Green ratio of phase p, q p,max Maximum vehicle arrival rate for each lane combination corresponding to phase p, s represents traffic flow saturation flow rate, g p,min Minimum green duration, C, representing a set phase p in the signalling system min 、C max Respectively represent the lower and upper bounds, g ', of the signal period' p Green duration, g, for adjusted phase p p To adjust the green duration of the front phase p.
13. The traffic signal control method according to claim 1, wherein after the special vehicle passes through the intersection, the corresponding traffic control signal recovery is performed on the passed intersection based on the signal green wave control information of the intersection until the original timing of the passed intersection is recovered, and the method comprises:
under the condition that the control mode of the traffic control signal is the control of the main road coordination signal, the minimum positive integer N and the corresponding new green light time length of each phase of the current intersection are determined
To meet the minimum green light duration requirement:
min N
s.t.C new ＝NC-(r′ i +g′ i )
C new >0
C min ≤C new ≤C max
in the formula, C new Is the new signal period, C is the original signal period, r' i ，g′ i The adjusted red light duration and green light duration, g p To adjust the green duration, g ', of the front phase p' p To adjust the green duration of the post-phase p, g p,min The minimum green light duration corresponding to the phase p; c min 、C max Representing the lower and upper bounds of the signal period.
14. A traffic signal control system for preferential passage of a particular vehicle, comprising:
the intersection determining module is used for acquiring a path to be traveled of a special vehicle and determining a plurality of intersections to be controlled by the execution signal according to the path to be traveled;
the speed calculation module is used for acquiring position data of the special vehicle in the running process in real time and calculating the average running speed of the special vehicle in a previous preset time period at the current moment based on the position data;
the green wave control information determining module is used for determining signal green wave control information of an intersection which is within a preset distance ahead along the current position in the path to be traveled by the special vehicle based on the average traveling speed and a preset time threshold, wherein the preset distance is determined according to the average traveling speed and the preset time threshold;
and the signal recovery module is used for performing corresponding traffic control signal recovery on the signal green wave control information corresponding to the passing intersection after the special vehicle passes through the intersection to be subjected to signal control until the original timing of the passing intersection is recovered.
15. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for traffic signal control for preferential passage of special vehicles according to any one of claims 1 to 13 when executing the program.
16. A non-transitory computer-readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, implements the traffic signal control method for priority passage of special vehicles according to any one of claims 1 to 13.
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