Summary of the invention
In order to solve the shortcomings of the prior art, the purpose of the present invention is to provide a kind of intersection control method and it isSystem.It is different from traditional Vehicle Detection method, the present invention is based on car networking technologies, can be in complicated traffic environment to vehicleVarious information are collected, and can also efficiently be controlled according to the information of collection crossing traffic.
Firstly, proposing a kind of intersection-traffic control method for the efficiently current purpose for realizing intersection vehicle, walkingSuddenly include: the first step, obtain the location data of vehicle, according to the location data, compare the driveway partition information at the crossing,Determine the passage direction of vehicle and the vehicle fleet size in each direction of passing through；Second step, the vehicle on the current directionWhen quantity is 0, the signal lamp that the passage direction is arranged updates signal condition according to minimum green time；Otherwise, each passage is calculatedThe down time of first car on direction, and when stopping according to the down time of first car sequence prior-release from long to shortBetween longest current direction；Third step follows the steps below control to the vehicle that signal lamp on current direction is green light: meterWhether calculate the vehicle can be with preset maximum speed by the crossing, if can be to send speed-raising signal to the vehicle；Otherwise, reduce-speed sign is sent to the vehicle；Control is followed the steps below to the vehicle that current directional signal light is red light:Can the vehicle be calculated during first green light after current red light by the crossing, if can be with, to describedVehicle sends the signal for keeping driving status；Otherwise, reduce-speed sign is sent to the vehicle；4th step tracks the vehicle, sentencesWhether the break vehicle and the signal lamp runs according to above-mentioned control, if so, jumping to the first step；Otherwise, report is sentAlert signal.
Optionally, intersection-traffic control method as described above, wherein in the first step, the positioning data of vehicles is by iLocating base station is obtained by following steps, i >=3: step a1 receives the broadcast data packet of positioning label；The positioning label is setIt is placed on the vehicle, the broadcast data packet includes the message of the vehicle for identification；Step a2, with wherein 1 instituteStating locating base station is master base station Mm, i >=m >=1 is to calculate separately the broadcast data from base station with locating base station described in remainingIt wraps to the M of each locating base station1~MiPropagation delay be respectively τd1~τdi；Step a3, according to the propagation delay τd1~τdiThe broadcast data packet is calculated to master base station MmWith respectively from base station MiBetween propagation distance difference Δ dmi=(τdm-τdi) * c,In, c indicates the speed that the broadcast data packet is propagated, τdmIndicate the broadcast data packet to master base station MmPropagation delay, τdiIndicate the broadcast data packet extremely from base station MiPropagation delay；Step a4, according to each propagation distance difference Δ dm1~Δ dmiSimultaneous Equations solve equation group, obtain the coordinate when broadcast data packet is propagated, i.e., the positioning number of the described vehicleAccording to.
Optionally, intersection-traffic control method as described above further includes according on each current direction wherein in second stepVehicle queue length determines the step of prior-release sequence: being the passage direction of red light to signal lamp, obtains the passage directionUpper vehicle fleet size, judges whether the vehicle fleet size on the passage direction reaches preset threshold value, if reaching the preset threshold value,Then prior-release passage direction；Otherwise, when stopping according to the sequence prior-release of the down time of first car from long to shortBetween longest current direction.
Optionally, intersection-traffic control method as described above, wherein in second step, first car on each current directionDown time is calculated by following steps and obtained: step 201, calculating the acquisition clearance direction green light bright time is t0；Step 202,It calculates in same signal lamp cycle, the arrival time of first car is respectively t1, t2, t3 ... tn before remaining all directions stop line；Step 203, the down time of each current direction first car is respectively Δ t1=t1-t0, Δ t2=t2-t0..., Δ tn=tn-t0。
Optionally, intersection-traffic control method as described above, wherein in the third step, sent to the vehicleSpeed-raising signal includes: the signal for making the vehicle pass through the crossing with preset maximum speed；Subtract to what the vehicle was sentFast signal includes: the signal for making the vehicle parking.
Optionally, intersection-traffic control method as described above, wherein on the passage direction of the prior-release, signal lampIt is arranged to following steps to jump: step 1, obtaining the queue length on the passage direction that crossing current preference is let passMeanwhile according to each crossing be averaged maximum queue length setting threshold valueStep 2, whenWhen, the signal lamp with line directionExecute maximum green time tmax；Step 3, whenWhen, it is t that the signal lamp in the passage direction, which executes green time,s,
The present invention goes back while providing a kind of crossing traffic control system, comprising: signal lamp control system, it is described for controllingSignal lamp on each current direction；Further include: positioning label, i locating base station, i >=3；The positioning label, is set to vehicleOn, for the preset period, to each locating base station broadcast data packet, the broadcast data packet to include institute for identificationState the message of vehicle；Each locating base station, for receiving the broadcast data packet of the positioning label, according to the broadcast dataThe location data of vehicle, uploads the location data to the signal lamp control system where packet calculates the positioning label；It is describedSignal lamp control system is arranged to perform above-mentioned intersection-traffic control method.
Optionally, crossing traffic control system as described above, wherein the positioning label further includes having acceleration sensingDevice, the acceleration transducer are used to incude the acceleration of the vehicle；The positioning label is broadcasted to each locating base stationThe period of data packet shortens with the increase of the acceleration.
Optionally, crossing traffic control system as described above, wherein the positioning label include RF power amplification andLow frequency induction unit；The locating base station includes low frequency signal transmission unit and UWB communication unit；The low frequency signal hairUnit is sent to interact with the low frequency induction unit, to carry out zone location to the positioning label；The UWB communication unit and instituteRF power amplification communication is stated, and is connect with the signal lamp control system, the UWB communication unit is used for and the Signalized controlSystem interaction, and forward to the RF power amplification control signal of the signal lamp control system.
Beneficial effect
It is different from traditional Vehicle Detection method, the present invention is based on car networking technologies, can be in complicated traffic environmentThe various information of vehicle are collected, and crossing traffic can also efficiently be controlled according to the information of collection.
In particular, the present invention establishes a kind of high-precision positioner based on car networking and the control of the crossing based on the deviceSystem.Locating base station used in this system can be realized the high accuracy positioning of vehicle, and positioning accuracy error is within 0-10cm.LetterShip's light control system can automatically combine positioning result with intersection traffic situation, reduce artificial statistics bring and missDifference, and comprehensive regulation can be carried out according to crossing traffic situation in real time, improve the traffic efficiency of intersection.
Crossing traffic control system provided by the present invention can be by integrated UWB communication unit, with Ethernet, ultra wide bandMode realize with signal lamp control system and with positioning label interaction, to obtain the vehicle characteristics of target vehicle, rowStatus information is sailed, realizes the quick and precisely matching of vehicle and road information.In this way, being provided with for the adjustment of speed, vehicle lane-changingThe data of power are supported.The present invention can also further ensure that traffic signal timing is modified and to vehicle by the tracking to vehicle in real timeControl signal accuracy.Sufficient foundation is provided for the optimization of intersection timing, significantly improves the traffic capacity of intersection.
Other features and advantages of the present invention will be illustrated in the following description, also, partly becomes from specificationIt obtains it is clear that understand through the implementation of the invention.
Specific embodiment
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, it should be understood that preferred reality described hereinApply example only for the purpose of illustrating and explaining the present invention and is not intended to limit the present invention.
Fig. 2 is the block diagram of crossing traffic control system according to the present invention, including signal lamp control system, is arranged in vehicleOn positioning label, can correspond in Fig. 2 shown in the small frame of white and at least three locating base station.
Therein to be set to base station, hardware mainly includes following sections:
Base station bottom plate: each functional module is in communication with each other, the bridge joint substrate mutually controlled；
Power unit: the 3.3-12V that entire base station system needs is provided.Input can be direct current 12-48V, be also possible toPOE supply input；
UWB core board module: three parts are realized comprising processor, Ethernet control, UWB ultra wide band, as entire systemThe logic control of system, ethernet communication are realized, ultra wide band positions and UWB communication unit；
WIFI routes plate: providing the realization of wireless communication connection；
Low frequency signal transmission unit, including low frequency induction transmission board: providing the function of low frequency induction transmitting base station；
Imput output circuit: external input/output function is provided；
Operating system in the locating base station is controlled according to following process:
Step 1: electrification reset；
The calling of Step 2:bootloader starting and kernel program；
Step 3: system initialization, including memory management module, ticking clock, parameter list, Ethernet, SPI, UWB mouldBlock, hardware random number generation module, real-time clock module, low frequency induction sending module, SD card module etc.；
Step 4: being arranged according to parameter list, regularly sends and receive base station calibration data；
Step 5: the tag location broadcast bag data received is handled in real time；
Step 6: it uploads in real time and sends calibration data, receives calibration data, tag location broadcast bag data；
Step 7: real-time processing server sends order, including reception, processing and response；
Step 8: other logic modules in whole-process control system operation, including SD card module, low frequency induction are sentModule etc..
In above system, each positioning label being arranged on vehicle may include following hardware:
Power unit: 3.3V and 5V that circuit board needs are provided, the control and protection of battery charging is provided；
CPU part: the control of the logical AND function of whole system is provided；
The part UWB: all controls that ultra wide band is positioned at super broad band radio communication are provided；
Acceleration sensing: power managed and positioning logic Added Management are provided；
Low frequency induction part: zone location function is provided；
RF power amplification: improving UWB RF signal power, increases communication distance.
The software of above-mentioned positioning label operates as follows:
Step 1: electrification reset；
The calling of Step 2:bootloader starting and kernel program；
Step 3: interrupt vector table offset setting；
Step 4: system initialization, including it is ticking clock, house dog, parameter list, SPI, low frequency induction receiving module, fixedWhen device, acceleration transducer, UWB module, electric power detection module, power managed module etc.；
Step 5: regularly sending for broadcast data is carried out according to the setting of parameter list；
Step 6: the various orders received, including command analysis, processing and response are handled；
Step 7: power managed is carried out according to the state of the setting of parameter list and acceleration transducer.
Above-mentioned system obtains the location data of vehicle, according to institute by the interaction between positioning label and locating base stationLocation data is stated, the driveway partition information at the crossing is compareed, determines the passage direction and each direction of passing through of vehicleVehicle fleet size.Then crossing traffic is controlled in real time according to mode shown in FIG. 1 by the signal lamp control system in systemSystem:
The direction of prior-release is determined according to the vehicle fleet size on current direction, down time first and controls signal lampState: when the vehicle fleet size on the current direction is 0, the signal lamp in the passage direction is set according to minimum green time moreNew signal state；Otherwise, calculate the down time of first car on each current direction, and according to the down time of first car byIt grows to short sequence prior-release down time longest current direction；
Then, the case where vehicle passes through crossing is calculated, sends corresponding control signal to vehicle.It is right for example, referring to Fig. 4Signal lamp is that the vehicle of green light follows the steps below control on current direction: calculate the vehicle whether can with it is preset mostBig speed is by the crossing, if can be to send speed-raising signal to the vehicle, control vehicle accelerates to section speed limit VmaxPass through as early as possible；Otherwise, reduce-speed sign is sent to the vehicle.Referring to Fig. 5, the vehicle that current directional signal light is red light can be pressedControlled according to following steps: can calculate the vehicle pass through the road during first green light after current red lightMouthful, if can be to send the signal for keeping driving status to the vehicle；Otherwise, reduce-speed sign, control are sent to the vehicleVehicle deceleration makes it pass through intersection during second green light after the red light terminates to Vi；
The lasting tracking vehicle, judges whether the vehicle and the signal lamp run according to above-mentioned control, ifIt is then to jump to the first step；Otherwise, alarm signal is sent.So until changing speed control strategy or integrative design intersectionThe demand etc. of real-time adaptive variation strategy is completed, and stops the tracking to the vehicle for completing control strategy at this time.
In an implementation mode, the positioning to vehicle can be carried out by mode shown in Fig. 3:
Step 1: 3 locating base stations A, B, C are installed in localization region, 1 positioning label W is installed on vehicle.
Step 2: it after positioning device electrifying startup, establishes and communicates with shovel material control system server.It was positioned every 1 secondCurrent breath data can be reached the server by UDP transmission mode automatically by base station.
Step 3: for server according to the data received, selection base station A is master base station, other 2 base stations be from base station,It is respectively τ that estimation outgoing label, which is transmitted a signal to up to two B and C base sites propagation delays,d1, τd2, then label and the two base sitesBetween range difference Δ d12=(τd1-τd2)*c。
Step 4: it is respectively τ that estimation outgoing label, which is transmitted a signal to up to two B and C base sites propagation delays,d1, τd3, then markRange difference Δ d between label and the two base sites13=(τd1-τd3)*c。
Step 5: according to two equations of Step3 and Step4, the position of vehicle W is calculated, that is, realizes the positioning of vehicle.
Spacing since in intersection, vehicle class is various, and between vehicle is closer, conventional truck positioning and message tubeThe work of reason system will expend a large amount of manpower and time, and be easy to appear mistake.And positioning method of the present inventionThe high-precision positioner based on car networking can be established, positioning accuracy reaches 0-10cm.
The satisfy the need control of oral sex messenger of this hair can be showed by mode shown in fig. 6.This real-time adaptive clearance machineSystem.Passing vehicle can be wanted to determine current clearance duration and transfer sequence by rather than depending on unduly by be in current crossingThe traffic flow conditions of previous cycle.Meanwhile determining that the mode of clearance sequence is also more flexible according to the quantity of all directions vehicle,No longer it is fixed and invariable.The difficult point of the configuration and the maintenance that need periodically to do system operating scheme for conventional traffic system, thisUsing a variety of real-time adaptive control strategies based on traffic flow distribution safety regulation, can substantially reduce system on human is systemThe dependence of correction makes system become more stable, more intelligent, more reliable:
For example, the default operating scheme that traditional crossing is singly put is: North-south-Xi-east, still, when queuing happens variationWhen, system can match new clearance scheme in time, so that total vehicle delay is minimum, i.e., scheme updates are as follows: north-Xi-Dong-south is (such asShown on the right side of Fig. 6).When a direction is without vehicle queue, then it will use progress in minimum green time (5 seconds or so) excessively, fromAnd other directions is made to obtain more transit times.
All lanes are numbered, set ψ is taken, judge the down time of first parking vehicle in each lane, andIt is arranged in order.It chooses first car down time longest lane to let pass, if having the queuing in lane during clearanceReach threshold value, then prior-release reaches the lane of threshold value, the vehicle in emptying intersection.
The advantages of technical solution of the present invention, is mainly reflected in:
This system can be obtained by the cooperation of locating base station and positioning label by high-precision traffic behavior analysis systemVehicle data information, with this effective optimization for helping manager to carry out intersection signal timing.In particular, signal of the invention is matchedShi Bianhua breaks through the constraint of Traditional Thinking, can be directed to the specific current demand in each direction, it is adaptive to carry out dynamic traffic signalsReal-time optimization is answered, optimization is really refine to each vehicle, farthest guarantees the unimpeded, orderly of traffic, eliminates biographyThe hysteresis effect that togetherness should control.
Those of ordinary skill in the art will appreciate that: the foregoing is only a preferred embodiment of the present invention, and does not have toIn the limitation present invention, although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the artFor, still can to foregoing embodiments record technical solution modify, or to part of technical characteristic intoRow equivalent replacement.All within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should all includeWithin protection scope of the present invention.