Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the technical problems in the prior art, the invention provides the road side type guiding method and system based on the vehicle-road cooperation, which have the advantages of simple implementation method, low implementation cost and complexity, safe and reliable vehicle running and high intersection communication efficiency, can solve the problem of 'two-difficulty area' of the vehicle entering the intersection, and improve the safe and reliable vehicle running and the intersection communication efficiency.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a road side type guiding method based on vehicle-road cooperation comprises the following steps:
s1, taking a designated area on an entrance road of a destination intersection as a guide area in advance, and arranging guide indicating units along one side or two sides of a road in the guide area;
s2, when the vehicle reaches the guiding area on the entrance lane of the destination intersection, acquiring the vehicle state information of the current vehicle, the road condition information of the entrance lane of the current destination intersection and the information of a signal lamp at the destination intersection;
and S3, controlling the guide indication unit to send out indication information according to the acquired vehicle state information, road condition information and signal lamp information, so as to guide the current vehicle to stop or decelerate in advance when the current vehicle reaches a target intersection and is queued or cannot pass through an intersection stop line at the time of yellow light.
Further, the vehicle state information includes one or more of speed, deceleration, and distance between the vehicle and the destination intersection, the traffic information includes the number of queued vehicles and/or traffic flow on the road, and the signal light information includes one or more of remaining green light time, next green light on time, yellow light time, and green signal ratio.
Further, the step of step S3 includes:
s31, judging whether a parking lot exists: judging whether a queuing vehicle exists when the current vehicle reaches a target intersection according to the acquired vehicle state information, road condition information and signal lamp information, if so, executing a step S32, otherwise, executing a step S33;
s32, judging whether the stop line can be passed: judging whether the current vehicle can pass through a stop line of a target intersection at the current yellow light time or not according to the acquired vehicle state information, road condition information and signal light information, and if not, turning to the step S33;
s33, controlling a guide indication unit: and controlling the guide indication unit to send out deceleration or stop indication information so as to guide the current vehicle to stop or decelerate in advance.
Further, the specific step of determining whether there is a vehicle in line when the current vehicle reaches the destination intersection in step S31 includes:
s311, calculating the number N of first vehicles which need to be consumed in the time period that the current vehicle drives to the intersection stop line from the current position according to the current speed1:
Wherein, T1The time required for a vehicle to travel from a current position to an intersection stop line at a current speed, D is the distance between the current vehicle and the intersection stop line, V is the travel speed of the current vehicle, Q is the average traffic flow of a current destination intersection entrance lane, and N is the time at the current time T0The number of queued vehicles existing at the entrance lane of the target intersection;
and calculating T1A second number N of vehicles theoretically capable of dissipating during the time periodc:
Nc=S×Xi×Ti
Wherein S is the saturation flow rate at the intersection;
s312, comparing the first number of vehicles N1And the second number of vehicles NcIf the first number of vehicles N is judged1>Number of second vehicles NcIf the current vehicle is judged to have the vehicle in line when the current vehicle drives to the intersection stop line from the current position at the current speed, otherwise, the vehicle in line is judged not to exist.
Further, the step of determining whether the current vehicle can pass through the destination intersection stop line at the current yellow light time in step S32 includes:
s321, calculating a first distance L which can be passed by the current vehicle in the yellow light time according to the running speed of the current vehiclep:
And calculating a second distance D between the current vehicle and the stop line of the intersection when the yellow light is ony:
Wherein, TyellowThe time of yellow light, V the running speed of the current vehicle, and D the stop of the current vehicle at the intersectionDistance between stops, TgreenThe remaining time of the green light;
s322, comparing the first distance LpAt the second distance DyIf D is judgedy>LpAnd if not, judging that the current vehicle can normally pass through the intersection stop line when the yellow light is turned on.
Further, the guidance indication unit includes a plurality of guidance lights arranged at intervals to form a roadside green light guide belt, the guidance lights are all green lights in a normal state, when the vehicle reaches a stop line, no vehicle queues up and the vehicle can pass through an intersection stop line at a yellow light time, each of the guidance lights is kept as a green light, and when the guidance indication unit is controlled in step S3, specifically, if there is a vehicle in queue when the current vehicle reaches a destination intersection or the current vehicle cannot pass through the intersection stop line at the yellow light time, the guidance light closest to the vehicle is sequentially controlled to be changed into a red light to guide the vehicle to decelerate or stop in the vehicle driving process.
Further, the specific step of sequentially controlling the guidance light closest to the vehicle to be changed into the red light includes:
s331, finding a destination guidance light i so as to satisfy { (L)s+Dl)-DiIs the minimum positive value, where LsFor safe stopping distance, DlPredicted queue length for each lane and DlLen is the length of the standard vehicle, N is the number of possible stops per lane and N is (N) ═ len1-NC)÷m,N1The number of the first vehicles which need to be consumed in the time period that the current vehicle drives from the current position to the stop line of the intersection at the current speed, NcIs T1The number of second vehicles which can be theoretically dissipated in the time period, wherein m is the number of lanes at the entrance of the intersection;
s332, calculating the current time T of the current vehicle0Time T required for traveling to the destination guide lamp i2Controlling the destination pilot lamp i at time T2Changing the red light to the red light, and keeping the red light to pass the current entrance way again;
s333. during each time intervalPartition
And then controlling the next guide lamp to become a red lamp, and keeping the red lamp to go to the current entrance lane again, wherein d is the distance between the guide lamps, and V is the running speed of the current vehicle.
A roadside type guiding system based on vehicle-road cooperation comprises:
the guidance indicating unit is arranged along one side or two sides of a road in a guidance area, and the guidance area is a designated area on an entrance way of the destination intersection;
the vehicle-mounted unit is used for acquiring vehicle state information of a current vehicle and sending the vehicle state information to the road side control unit;
the information acquisition unit is used for acquiring road condition information of an intersection entrance road and information of signal lamps and sending the information to the road side control unit;
and the roadside control unit is used for receiving the vehicle state information sent by the vehicle-mounted unit, the road condition information sent by the information acquisition unit and the information of the signal lamp, and controlling the guide indication unit to send out indication information according to the received vehicle state information, road condition information and signal lamp information when the vehicle reaches the guide area on the entrance lane of the destination intersection so as to guide the current vehicle to stop or decelerate in advance when the current vehicle reaches the destination intersection and can have queued vehicles or the current vehicle cannot pass through an intersection stop line at the time of yellow light.
Further, the guide indication unit specifically comprises a plurality of indication lamps, and each indication lamp is arranged at intervals according to a specified interval.
Further, the information acquisition unit comprises image acquisition equipment for acquiring image information, a detector for detecting the traffic flow of the road and acquisition equipment for acquiring signal lamp information.
Compared with the prior art, the invention has the advantages that:
1. according to the invention, the guiding and indicating unit is arranged on the intersection entrance lane, when the vehicle enters the guiding area, the guiding and indicating unit is controlled to send the indicating information according to the vehicle state information, the road condition information of the current intersection entrance lane and the information of the signal lamp, when the vehicle arrives at the target intersection, queuing vehicles can exist or the vehicle can not pass through the intersection stop line at the time of yellow light, the vehicle can be guided to stop or decelerate in advance, the driver is prevented from entering the dilemma area, and the traffic safety of the intersection is improved. Compared with the traditional ways of prolonging the green time, adjusting the yellow time and the like, the timing scheme of the signal lamp at the intersection does not need to be changed, so that the passing efficiency of the whole intersection is not influenced, and the passing efficiency of the intersection can be ensured on the basis of effectively solving the problem of the dilemma area.
2. The invention realizes early warning by arranging the guide indicating unit at the roadside outer side, judges and controls guide indication through information interaction between vehicles and roads after the vehicles enter the guide area, and compared with the traditional vehicle-mounted early warning mode, the invention can realize vehicle early warning without interconnection and intercommunication between vehicles and roads, thereby greatly reducing the realization cost and realizing the complexity.
3. The guiding and indicating unit further adopts the technical scheme that the guiding lamp belts are arranged on the central separation belt and the vehicle-mounted separation belt to form the green lamp guiding belt, the driver is reminded of whether the vehicle is normally driven or decelerated and stopped by controlling the change of the lamp color of the guiding lamp, the driver can conveniently and clearly obtain the guiding information based on the mode of the guiding lamp belts, and the guiding and indicating unit is low in installation cost and strong in practicability.
Detailed Description
The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.
As shown in fig. 2, the road-side guiding method based on vehicle-road coordination of the present embodiment includes the steps of:
s1, taking a designated area on an entrance road of a target intersection as a guide area in advance, and arranging guide indicating units along one side or two sides of a road in the guide area;
s2, when the vehicle reaches a guide area on a target intersection entrance way, acquiring vehicle state information of the current vehicle, road condition information of the current target intersection entrance way and signal lamp information of the target intersection;
and S3, controlling a guide indication unit to send out indication information according to the acquired vehicle state information, road condition information and signal lamp information so as to guide the current vehicle to stop or decelerate in advance when the current vehicle reaches a target intersection and is queued or cannot pass through an intersection stop line at the time of yellow light.
According to the embodiment, the guiding indication unit is arranged in the guiding area on the intersection entrance way, when a vehicle enters the guiding area, according to the vehicle state information, the road condition information of the current intersection entrance way and the information of the signal lamp, the guiding indication unit is controlled to send the indication information to guide the driver to stop at a reduced speed or continue to pass, when the vehicle reaches a target intersection, a queued vehicle exists or the vehicle cannot pass through an intersection stop line at a yellow light time, the vehicle can be guided to stop or decelerate in advance, the driver can be guided to make scientific and reasonable decision judgment at the intersection, the driver is prevented from entering a dilemma area, traffic safety accidents caused by the personal judgment error of the driver are effectively avoided, and the passing safety of the intersection is improved. Compared with the traditional mode of prolonging the green light time and adjusting the yellow light time, the timing scheme of the signal light at the intersection does not need to be changed, so that the passing efficiency of the whole intersection cannot be influenced by increasing the green light time, the yellow light time and the like, and the passing efficiency of the intersection can be ensured on the basis of effectively solving the problem of the dilemma.
And this embodiment realizes the early warning based on the guider in the roadside formula outside, begins early warning judgement and control guide instruction through the information interaction between the vehicle road after the vehicle gets into the guide region, compares in traditional on-vehicle early warning mode, only needs arrange the guide indicating unit in certain region of crossing entry road, need not to reach car, vehicle road interconnection intercommunication simultaneously, only needs the vehicle to the roadside transmission information, can significantly reduce and realize cost and realization complexity.
In this embodiment, the vehicle state information includes speed, deceleration, distance between the vehicle and the destination intersection, the road condition information includes the number of queued vehicles, traffic flow, and the like on the road, and the signal lamp information includes remaining green lamp time, next green lamp turn-on time, yellow lamp time, green signal ratio, and the like, and may further include signal lamp timing status and the like.
In this embodiment, the guidance indication unit specifically includes a plurality of guidance lights arranged at intervals, that is, a roadside green light guide belt is formed by the plurality of guidance lights arranged at intervals, the guidance lights are all green in a normal state, the vehicle is guided to decelerate or stop before entering the dilemma area by controlling the change of the colors of the guidance lights and the traffic lights, specifically, when the vehicle reaches a stop line, no vehicle queues up, and the vehicle can pass through the intersection stop line at the time of yellow light, each guidance light is kept as a green light, if there is a vehicle in queue when the current vehicle reaches a target intersection, or the current vehicle cannot pass through the intersection stop line at the time of yellow light, the guidance light closest to the vehicle is sequentially controlled to be changed into a red light to guide the vehicle to decelerate or stop in the vehicle driving process. The guide lamp body can be arranged on the central separation belt and the non-mechanical separation belt, the mode that the guide lamp belt is arranged on the central separation belt and the non-mechanical separation belt is adopted, a driver can conveniently and quickly and clearly obtain guide information, the installation cost is low, and the practicability is high. The guide lamp can be a light emitting device such as an LED light emitting module. The guide area is specifically a lamp strip area provided with a guide lamp, and can be taken into a specified length area before the dilemma area.
In a specific application embodiment, the guidance lamps are symmetrically arranged on the central separation belt and the non-motor separation belt every 5 meters from the stop line to form a roadside green lamp guide belt, the guidance lamps can be controlled to be changed into red and green colors, the guidance lamps are displayed in green to represent that the vehicle can keep the existing speed to normally run, and when the guidance lamps are displayed in red, the vehicle needs to be decelerated and stopped. When the vehicle which cannot normally drive over the stop line runs to the safe parking distance, the nearest guide lamp in front of the vehicle is controlled to display a red lamp to warn a driver to stop at a reduced speed, and the subsequent guide lamps are sequentially changed into the red lamps according to the time interval determined by the vehicle speed.
In this embodiment, a roadside control unit is specifically and previously arranged at the intersection, and when the vehicle reaches the guidance area, specifically, the light zone, in step S2, the vehicle sends self state information to the roadside control unit, where the self state information includes information such as vehicle speed, deceleration, and distance to the stop line; the road side control unit acquires the vehicle state information of the current vehicle, the road condition information of the current target intersection entrance road and the information of the target intersection signal lamp, and controls the guiding and indicating unit, wherein if the current vehicle arrives at the target intersection, a queuing vehicle exists or the current vehicle cannot pass through an intersection stop line at the time of yellow light, the guiding and indicating unit is controlled to send out corresponding prompt information so as to guide the current vehicle to stop or decelerate in advance.
As shown in FIG. 1, when the yellow light is on, the vehicle is according to the stop line distance DyAt the maximum safe parking distance DSDistance L from the vehicle to the yellow lightpIn between, the vehicle is in the area of difficulty in two promptly, neither can normally drive away nor safe parking, has great potential safety hazard. The embodiment gives the signal lamp guide when the vehicle does not enter the dilemma area, so that the vehicle can be indicated to normally pass through the vehicle, the vehicle which cannot pass through is indicated to decelerate and stop, and the problem that the vehicle can enter the dilemma area is avoided.
In this embodiment, the step S3 includes:
s31, judging whether a parking lot exists: judging whether a queuing vehicle exists when the current vehicle reaches a target intersection according to the acquired vehicle state information, road condition information and signal lamp information, if so, executing a step S32, otherwise, executing a step S33;
s32, judging whether the stop line can be passed: judging whether the current vehicle can pass through a stop line of the destination intersection at the current yellow light time (namely when the yellow light is started) or not according to the acquired vehicle state information, road condition information and signal light information, and if not, turning to the step S33;
s33, controlling a guide indication unit: and controlling the guide indication unit to send out indication information of deceleration or stop so as to guide the current vehicle to stop or decelerate in advance.
According to the embodiment, whether the vehicles can queue up or not when arriving at the destination crossing is judged respectively according to the vehicle state information, the road condition information and the information of the signal lamps, whether the vehicles can pass through the destination crossing stop line at the current yellow light time or not is judged, if the vehicles can queue up or cannot safely pass through the crossing stop line at the yellow light time is judged, the guiding and indicating unit is controlled to send out the indicating information, the early warning can be sent out before the vehicles enter a dilemma area, and the vehicles are guided to decelerate or stop in time to avoid the problem that the vehicles can enter the dilemma area.
In this embodiment, the specific step of determining whether there is a vehicle in line when the current vehicle reaches the destination intersection in step S31 includes:
s311, calculating the number N of first vehicles which need to be consumed in the time period that the current vehicle drives to the intersection stop line from the current position according to the current speed1:
Wherein, T1The time required for a vehicle to travel from a current position to an intersection stop line at a current speed, D is the distance between the current vehicle and the intersection stop line, V is the travel speed of the current vehicle, Q is the average traffic flow of a current destination intersection entrance lane, and N is the time at the current time T0Temporary destination crossing entrance lane storageNumber of vehicles in line;
and calculating T1A second number N of vehicles theoretically capable of dissipating during the time periodc:
Nc=S×Xi×Ti (3)
Wherein S is the saturation flow rate at the intersection;
s312, comparing the first number of vehicles N1And a second number of vehicles NcIf the first number of vehicles N is judged1>Number of second vehicles NcIf the current vehicle is judged to have the vehicle in line when the current vehicle drives to the intersection stop line from the current position at the current speed, otherwise, the vehicle in line is judged not to exist.
The saturation flow rate S at the intersection may be
And h is a saturated headway, specifically, the headway of the fourth vehicle which is queued continuously passing through the stop line during the period from green light of each vehicle at the tail of the queue is collected, and the average value of a plurality of (for example, 15) periods is continuously observed to be used as the saturated headway h, so that the saturated flow rate is obtained.
The specific steps of determining whether the current vehicle can pass through the destination intersection stop line at the current yellow light time in step S32 in this embodiment include:
s321, calculating a first distance L which can be passed by the current vehicle in the yellow light time according to the running speed of the current vehiclep:
And calculating a second distance D between the current vehicle and the stop line of the intersection when the yellow light is ony:
Wherein, TyellowIs the time of yellow light, V is the running speed of the current vehicle, D is the distance between the current vehicle and the stop line of the intersectionFrom, TgreenGreen light time;
s322, comparing the first distance LpAt a second distance DyIf D is judgedy>LpAnd if not, judging that the current vehicle can normally pass through the intersection stop line when the yellow light is turned on.
In this embodiment, whether a vehicle queue exists when the vehicle reaches the stop line or not is judged according to the roadside information and the obtained vehicle information, whether the vehicle can smoothly pass through the stop line at the time of yellow light is judged, if the vehicle queue exists or the vehicle cannot smoothly pass through the stop line at the time of yellow light, a proper guide light is controlled to turn red at a specified time, and the following guide lights are sequentially turned red and keep the red state until the signal light is turned green again; if there is no queue or a stop line can be passed during the yellow light time, the guidance light is kept green.
In this embodiment, the specific steps of sequentially controlling the guidance light closest to the vehicle to be converted into the red light include:
s331, finding a destination guidance light i so as to satisfy { (L)s+Dl)-DiIs the minimum positive value, where LsFor safe stopping distance, DlPredicted queue length for each lane and DlLen is the length of the standard vehicle, N is the number of possible stops per lane and N is (N) ═ len1-NC)÷m,N1The number of the first vehicles which need to be consumed in the time period that the current vehicle drives from the current position to the stop line of the intersection at the current speed, NcIs T1The number of second vehicles which can be theoretically dissipated in the time period, wherein m is the number of lanes at the entrance of the intersection;
s332, calculating the current time T of the current vehicle0Time T required for traveling to the destination guide lamp i2Controlling the destination pilot lamp i at time T2Changing the red light to the red light, and keeping the red light to pass the current entrance way again;
s333. in each time interval
And then controlling the next guide lamp to become a red lamp, and keeping the red lamp to go to the current entrance lane again, wherein d is the distance between the guide lamps, and V is the running speed of the current vehicle.
The specific safe parking distance LsSpecifically, the formula can be calculated as follows:
wherein, VlimFor the highest speed limit at the intersection, AsFor usual deceleration of the vehicle, TrThe average reflecting time of the driver.
The above time T2Specifically, the formula can be calculated as follows:
the embodiment adjusts the safe parking distance L by judging whether the intersection has queued vehicles or notsThe method can fully consider the factors of queuing vehicles while preventing the vehicles from entering the dilemma area, further reduce the potential safety hazard of vehicle driving and ensure the driving safety at the intersection.
In order to implement the method, the embodiment further includes a road-side type guiding system based on vehicle-road cooperation, where the system includes:
the guidance indicating unit is arranged along one side or two sides of a road in a guidance area, and the guidance area is a designated area on an entrance way of the destination intersection;
the vehicle-mounted unit is used for acquiring vehicle state information of a current vehicle and sending the vehicle state information to the road side control unit;
the information acquisition unit is used for acquiring road condition information of an intersection entrance road and information of signal lamps and sending the information to the road side control unit;
and the road side control unit is used for receiving the vehicle state information sent by the vehicle-mounted unit, the road condition information sent by the information acquisition unit and the information of the signal lamp, and controlling the guide indication unit to send indication information according to the received vehicle state information, road condition information and signal lamp information when the vehicle reaches a guide area on a target intersection entrance road so as to guide the current vehicle to stop or decelerate in advance when the current vehicle reaches the target intersection and has queued vehicles or the current vehicle cannot pass through an intersection stop line at the time of yellow light.
In this embodiment, the information acquisition unit includes image acquisition equipment for acquiring image information, a detector for detecting road traffic flow, acquisition equipment for acquiring signal lamp information, and the like.
The roadside control unit in this embodiment specifically corresponds to the guidance control step S3, and has the same implementation principle and technical effect, and is not described herein any more, and the specific roadside control unit may adopt a communication device RSU capable of implementing the function of the step S3.
In a specific application embodiment, as shown in fig. 3, when the vehicle reaches the light zone, the vehicle sends its own state (including vehicle speed, deceleration, and distance to the stop line) to the roadside control unit 4, the roadside control unit 4 determines whether there is a vehicle queue when the vehicle reaches the stop line, determines whether the vehicle can smoothly pass through the stop line at the time of yellow light, and controls a proper guide light to turn red at a specified time if there is a queue or the vehicle cannot smoothly pass through the stop line at the time of yellow light, and the following guide lights turn red in sequence and keep the red state until the signal light turns green again; if there is no queue or a stop line can be passed during the yellow light time, the guidance light is kept green.
As shown in fig. 3 and 4, in this embodiment, specifically, a guidance light strip is provided on the central division strip and the vehicle-to-vehicle division strip as a guidance indication unit, a roadside communication device RSU is arranged at the intersection as a roadside control unit 4, and a wide-angle camera is installed at the intersection for acquiring T0The number of vehicles N is present at the moment, a detector (such as a magnetic sensor, in particular) is arranged at the upstream of an entrance road to detect the road flow Q, an on-board unit OBU is arranged on the vehicle and communicates with an RSU installed at the road side to transmit the vehicle state information, and the information obtained by the vehicle is obtained by a road side communication device RSUAnd the information sent by the OBU is transmitted to the roadside control unit, edge calculation is carried out by combining the information acquired by the roadside from the camera, the detector and the signal lamp, and a corresponding color change instruction is sent to the roadside guide lamp after corresponding judgment (whether a queued vehicle exists or whether the vehicle can pass an intersection stop line at the time of yellow light when the vehicle reaches a target intersection is judged) is carried out according to the judgment steps. The signal lamp sends the residual green lamp time T to the road side control centergreen"Luxin ratio" XiThe next green light on time, the yellow light on time, etc.
The vehicle-mounted unit OBU of this embodiment specifically adopts 5G technique to interact with the RSU of the roadside, accomplishes the interaction between vehicle-mounted unit OBU and the roadside communication equipment RSU through using 5G technique, can make data transmission have fast and low delay, further improves and leads the efficiency.
The method of the present invention is further described below by taking an example of implementing intersection vehicle guidance by using the above method of the present invention in a specific application embodiment, wherein a system structure adopted is shown in fig. 4.
The related parameters related to the embodiment specifically include: average driver response time T
rThe usual deceleration of the vehicle is A
sStandard car length len, intersection maximum speed limit is V
limThe yellow light time at the intersection is T
yellowThe time for the vehicle to transmit information to the drive test control unit is T
0,T
0The number of vehicles queued at the time entrance lane is N, T
0The time-speed is V, T
0The time-green light residual time is T
green,T
0The distance D between the vehicle and the stop line is set as the guide lamp i (i is 1,2, 3 … … from the stop line), and the distance D between the guide lamp i and the stop line
i(ii) a The distance between the guide lamps is d, the number of lanes at the entrance of the intersection is m, the number of predicted stops at the intersection is n, the upstream flow of the intersection is Q, and the green ratio of the signal lamps at the intersection is X
iThe inlet-road saturation flow rate is S, and the time required from the detector to the stop-line at V is
Yellow light time carThe distance that the vehicle can pass is
Maximum safe parking distance of
When the yellow light is on, the distance between the vehicle and the stop line is
When the time for passing each guide light is t when the vehicle speed is V, the number of dissipated vehicles is estimated at the intersection
Dissipating capacity N at intersection
c=S×X
i×T
i. In the above variables, the time variable unit is s, the speed variable unit is km/h, and the distance variable unit is m.
As shown in fig. 5, the detailed steps for implementing road-side type guiding based on vehicle-road cooperation in the embodiment of the present invention are as follows:
step 1: a guide light strip is previously provided on the central dividing strip and the vehicle-to-vehicle dividing strip to form a green light guide strip, and a roadside control unit RSU, a camera, a detector and the like are arranged at the intersection, as shown in fig. 3.
Step 2: judging whether a stop line exists or not, comprising the following steps:
1) the on-board unit OBU of the vehicle uses the RSU to calculate the running speed V, the distance D from the stop line and the deceleration A of the vehicleSTransmitting the data to a road side control unit (RSU);
2) obtaining the vehicle at T through a camera0The number N of the vehicles in the queue at the entrance road and the average traffic flow Q of the entrance road are obtained through a camera;
3) calculating the intersection saturation flow rate S and the time T required for the vehicle to travel from D to the stop line at the current speed1The time period T1Number of vehicles N that may need to be dissipated1And the number of vehicles N theoretically capable of dissipating during the time periodc;
4) Comparison of N1And NcSize when N1>NcJudging that queuing vehicles exist when the vehicles reach the intersection; otherwise, no vehicle is queued;
5) if queuing exists, calculating the expected queuing length D of each lanel;
And step 3: judging whether the vehicle can safely pass through the stop line or not, comprising the following steps:
1) calculating the yellow light time T at the current running speed VyellowDistance L that can be passedpAnd the distance D between the vehicle and the stop line when the yellow light is ony;
2) Comparison DyAnd LpSize to judge whether the vehicle can safely pass the stop line when the yellow light is turned on, and when Dy>LpWhen the vehicle passes through the system, the vehicle cannot pass through the system normally; otherwise, the vehicle can normally pass
And 4, step 4: the pilot light color control includes:
a) when there are queued vehicles present when the vehicle reaches the stop line:
1) calculating the possible number n of the parking in each lane and the parking length D of each lanelAnd a safe parking distance Ls;
2) finding a target guiding lamp i to enable the target guiding lamp i to be away from the stopping line distance Di, and satisfying { (L)s+Dl)-DiIs the minimum positive value;
3) calculate from T0Time T to destination guidance light i2Then the ith guiding lamp is at T2Then changing the red light to the red light, and keeping the red light to the entrance passage to pass again;
4) changing the next guiding light to red light at each time interval t, and keeping the red light to the entrance passage to pass again;
b) no vehicles are queued when they reach the stop-line and the vehicle cannot pass the stop-line at yellow light time:
1) at this time DlTo 0, calculate the safe stopping distance Ls, find a destination guidance light i, so that the guidance light i is at a distance D from the stop linei,{(Ls+Dl)-DiIs the minimum positive value;
2) calculate from T0Time T to pilot lamp i2Then the ith guiding lamp is at T2Then changing the red light to the red light, and keeping the red light to the entrance passage to pass again;
3) after each time interval t, the next guidance light changes to red and keeps the red light passing to the entrance lane again.
c) No vehicles are queued when they reach the stop-line and the vehicle is able to pass the stop-line at yellow light time:
the guidance light remains green until it turns red when a vehicle cannot pass through it normally.
Besides the light strip composed of the guide lamps, the guide indicating unit can adopt other indicating devices capable of providing indicating information, such as a display and the like, according to actual needs, or further additionally arrange information display devices such as a display and the like on the basis of the arrangement of the guide lamps, so that a driver can obtain more prompting information.
The invention can be suitable for intersections controlled by two phase signals to ensure reasonable vehicle guiding, can also be applied to other types of intersections to realize vehicle guiding according to actual requirements, can also be suitable for green wave coordination control roads to provide information reminding for vehicle drivers, and further can be combined with a vehicle-mounted early warning mode to be matched with a vehicle-mounted module in a vehicle to further improve the early warning effect.
The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.