61 results about "Traffic wave" patented technology

The invention discloses a traffic-wave theory-based traffic influence area determining method of expressway accidents, which is used for determining space-time influence areas of traffic accidents after the traffic accidents happen on expressways without inlet and outlet ramps. The traffic influence area determining method comprises the following steps of: firstly determining traffic flow and traffic density of the expressways under different traffic conditions, drawing an expressway flow-density map, and then analyzing an accumulating and evanishing process of traffic waves in a process fromthe beginning of the accidents to the elimination of accident influence by using the traffic-wave theory, calculating a traffic wave speed of each stage, drawing a space-time evolution map of the traffic accidents, and finally determining influence time ranges and space ranges of the accidents in each stage. The traffic influence area determining method is simple and convenient and has good stability and high reliability; and according to the traffic influence area determining method, the influence area of the traffic accidents can be timely and accurately forecasted, and stable, timely and reliable traffic accident information can be supplied to the administrative department of the expressway, thereby the implementation efficiency of a rapid traffic accident disposing measure is improved.

The present invention discloses an online urban road route travel time estimation method based on the virtual vehicle locus reconstruction. The method comprises the following steps: an intersection upstream road vehicle detector is controlled by signals to obtain traffic flow data collected in real time, an intersection signal machine is configured to collect signal phase information in real time; the intersection traffic wave locus coordinates are estimated in real time, the impact wave i, ii, iii and iv and the time-space operation locus existed at the signal intersection are drew; the vehicle driving sate is simplified to the state of driving at a free flow speed on a non-queue road section or the state of parking at the intersection; the vehicle time-space coordinates corresponding to the special position information in the virtual vehicle coordinates are extracted to obtain the moment of the vehicle passing through the special position so as to realize the estimation of the vehicle route travel time. The online urban road route travel time estimation method based on the virtual vehicle locus reconstruction can obtain the propagation state of a vehicle departing at any time on the route and the online travel time at any plate on the arrival route so as to have higher timeliness and accuracy.

The invention relates to a method for predicting the range influenced by an abnormal traffic event of highway, and suitable for main lines of the highway. The method comprises that A Van Aerde traffic flow model of a road is established; a target function and an extremely low error threshold are set, and the duration of the event and the longest queuing time are predict; the traffic capacities of an accident point under multiple factors are determined, the upstream flows of the accident point within different time intervals are predicted based on data of vehicle detectors, and corresponding densities are obtained; the velocity of evanescent waves, the velocity of queuing waves at corresponding time and the influence length are calculated by utilizing the traffic wave theory; the position relation among the currently estimated queuing position, upstream and downstream ramps and the vehicle detectors is determined; and the solution of the target function is determined, and the longest queuing time and the range influenced by the event are determined. Based on establishment of the Van Aerde model, the method takes influence of traffic flow change and other factors on the velocities of the waves, the practical traffic flow features can be more effectively reflected, the adaptability is higher, and the prediction accuracy can be improved.

The invention discloses an intersection vehicle queuing length estimating method using low-sampling-rate GPS (Global Positioning System) data. The method comprises the following steps: estimating an intersection vehicle queuing length by using low-sampling-rate GPS data to provide a basis for optimization of intersection signal timing, and estimating an intersection running state; finding a queuing starting point and a queuing terminating point of vehicles through track point speeds and acceleration features of the vehicles, estimating a queuing wave and a queuing dissipation wave through a traffic wave theory and a curve-fitting theory in conjunction with periodical red lamp starting and ending moments, and determining a vehicle queuing length of an intersection through the queuing wave and queuing dissipation wave. In the method, a possible queuing key point and a possible non-queuing key point are found by using the speed features of vehicle track points, the feature of an acceleration value of the possible queuing key point is analyzed, and the queuing starting point and the queuing terminating point are found through the feature of the acceleration value of the possible queuing key point.

Provided is an artery vehicle track reconstruction method based on data fusion of electronic polices and fixed point detectors. The method includes the following steps: inputting a certain number of vehicles into a control system at specified time, specified roads or crossings; introducing constraints on the basis of an actual traffic running mode and a traffic wave associated theory, and screening a small number of reasonable tracks from possible tracks; taking actual traffic running conditions as reference, screening out an optimal track which is closest to reality from a small number of reasonable tracks by taking relevant parameters reflecting the actual traffic running conditions as standards, and then completing track reconstruction. The constraints include queuing overflow identification in fixed point detector; space-time area free flow speed acquisition; segmentation of upstream phase sequences and set timing periods; upstream input flow acquisition; and vehicle diversion behavior partition based on electronic police data. Reconstructed track adjustment is carried out on the basis of traffic parameters reflecting the actual traffic running conditions and then a final reconstructed track that better accords with reality is obtained, so the track reconstruction accuracy is improved.

The invention provides a flow-speed matching model and a travel time forecasting method and system. The method includes the steps of firstly, calculating theoretical travel time and traffic flow average speed of a road section; secondly, calculating the error between the theoretical travel time and actually-measured travel time, conducting feeding and adjusting on the traffic flow average speed according to the error, and renewing flow-speed data of the corresponding road section; thirdly, repeating the first step and the second step till the error is smaller than a preset threshold value, and storing the errors as a flow-speed matching model; fourthly, directly conducting matching in the flow-speed matching model through forecasted flow to obtain the average speed, and then calculating the travel time according to the average speed. According to the flow-speed matching model and the travel time forecasting method and system, the travel time is calculated according to the traffic wave principle, feeding and adjusting are conducted on the average speed, the calculation result is corrected unceasingly, and the flow-speed matching model is renewed; the travel time forecasting method is simple, and meanwhile the flow-speed matching model can be enriched and optimized in the travel time forecasting process so that the forecasting model can be higher in accuracy.

The invention relates to a lane-based real-time queue length prediction method and belongs to the technical field of intelligent transportation. The method, based on a traffic wave theory and a Robertson motorcade discrete model, compensates for the defect of a conventional queue length model which assumes that the arrival of vehicles complies with the same distribution (such as Poisson distribution), obtains the real-time number of vehicles passing by an upstream intersection and the license plate number data based on video detection data, obtains the proportions of vehicle traffic flow driving from different phases of the upstream intersection to different lanes of a downstream intersection, comprehensively takes account of the signal design of the upstream and downstream intersections,the length of a road section, and the discrete arrival characteristic of vehicles to predict the queue length in different lanes in real time, converts passive queue length estimation into active queue length prediction, and contributes to the signal optimization design of the associated intersections or the crowded road section in advance, so as to alleviate traffic congestion and improve a traffic environment.

The invention provides an intersection vehicle trajectory reconstruction method based on data fusion from the electric police and a fixed-point detector. The method comprises: long queuing identification is carried out, wherein the long queuing means that the queuing length exceeds the detector position; upstream-downstream lane flow mapping is carried out; and intersection vehicle trajectory reconstruction is carried out based on a traffic wave theory. When the queuing length is close to the detector, the detector occupancy rate increases and the passing vehicle number is reduced; and the long queue is identified based on fixed-point detection data of the section based on changing characteristics of the flow and occupation rate. According to the invention, the intersection vehicle trajectory reconstruction method has the following beneficial effects: the method is based on detection conditions of most of cities in the country and the 60s-aggregate flowing density and speed data and detection frequency are provided, so that the dependence on the high-frequency floating car trajectory data is eliminated.

The invention relates to a signal control intersection queuing length estimation method based on single section low frequency detection data. The signal control intersection queuing length estimation method based on single section low frequency detection data is characterized in that: the signal control intersection queuing length estimation method based on single section low frequency detection data includes the following steps: S1, using a single section fixed point detector to perform data acquisition on a signal control intersection; S2, determining whether the queuing length in each observation time interval is greater than the length detection range of the detector; if so, utilizing the detection data being close to the observation time interval to correct the arrival flow data of the observation time interval, and if not, entering the step S3; S3, according to the signal timing data of the signal control intersection, performing time segmentation on the detection data to match the signal timing data with the detection data; and S4, calculating the wave velocity of each traffic wave in the signal control cycle, calculating the maximum queuing length and the residual queuing length in the signal control cycle, and then returning to the step S2 until the maximum queuing length and the residual queuing length in each signal control cycle are calculated completely. Compared with the prior art, the signal control intersection queuing length estimation method based on single section low frequency detection data has the advantages of high accuracy and low data requirement.

The invention discloses a traffic event influence analysis method based on a traffic flow wave theory, falling in the technical field of traffic control. According to the invention, a flow-density-speed diagram is drawn firstly according to a specified jammed road section; the speed of a traffic wave from the upstream to the middle part of the jammed road section is then calculated to obtain the speed of the jammed traffic wave and the vehicle queue length from the upstream to the middle part; and the speed of the traffic wave from the middle part to the downstream of the jammed road section is finally calculated, to obtain the speed of dissipating the traffic wave from the middle part to the downstream of the jammed road section, so as to work out the vehicle queue waiting time of the jammed road section. The inventive method can improve the actual effective carrying capacity of highway, reduce rear-end crash accidents, and maintain traffic flow stability.

The invention discloses a dynamic expression method of an urban traffic road network grid lock transmission based on a GIS. The method comprises the steps of: when an intersection overflow in an urban road network is detected, querying and displaying attribute information such as the occurrence time, the severity level and the position; assisted by a manual report manner, utilizing modern traffic detection technologies such as video image processing to obtain the increasing speed of vehicle queuing namely a stop wave speed, estimating a queuing length, and accurately predicting the transmission range of a prediction grid lock; based on a traffic wave theory, estimating the time for forming crossing interlocking caused by the propagating of the vehicle queuing length; and under the conditions that no traffic control measures are taken and no traffic flow induction is carried out, the dynamic process of the urban traffic road network grid lock changing with time and space is obtained on an electronic map. A scientific and reasonable data support is provided to traffic managers for making corresponding control measures, and the purpose of preventing the large-scale transmission of the grid lock is achieved.

The invention provides a method for calculating the signalized intersection vehicle queuing length under the saturation condition. The method is based on the traffic wave theory and includes the following steps: (1) collecting signalized intersection information, (2) calculating the signalized intersection saturation queuing length, and arranging a vehicle detector at the position the signalized intersection saturation queuing length away from the stop line, (3) monitoring the occupation rate of the vehicle detector in real time, determining the vehicle queuing condition by detecting the occupation rate of the vehicle detector, and determining the state switching time point according to the occupation rate, and (4) conducting vehicle queuing length modeling calculation. Finally, the method for calculating the signalized intersection vehicle queuing length under the saturation condition is achieved. The method has the advantages of being high in accuracy and low in calculation complexity, and can meet the requirement of practical application.

The invention relates to a main road coordination control optimization method based on sampling track data. The method comprises the following steps of: 1), obtaining sampled vehicle track data, preprocessing the data to obtain track feature vectors and a prior arrival rate matrix; 2), on the basis of the prior arrival rate matrix, judging arrival states of sampled tracks in a period according toany group of set signal timing data, reconstructing track waves, estimating mapping arrival time and practical arrival time of the tracks, and obtaining signal control delay of the tracks at each intersection; and 3), accumulating the signal delay of all tracks at all intersections, obtaining total delay of all sampled tracks of main roads and an analysis formula for signal timing parameters at each intersection, establishing an optimization model based on constraints among the timing parameters, and carrying out solution through utilization of a multi-bee colony optimization algorithm. Compared with the prior art, the method has the advantages that space-time association is taken into consideration, a coordination effect is relatively good, and applicability is wide.

The invention discloses a coordinated guidance control method for highway ramps under traffic events, and belongs to the technical field of traffic control. The method includes: (1) obtaining an influence range of a traffic wave during a traffic event time period by using a queuing detector in a VISSIM; (2) determining the number of ramps used for coordinated control according to a ramp number ofa highway and the influence range of the traffic wave; and (3) obtaining the optimal ramp regulation rate by using the combination of a single point and a coordination level and providing path guidance, wherein the density is selected as a control variable at the coordination level, the coordination regulation rate is calculated through a PID control method, and vehicles are diverted to respectiveramps upstream of a congested point according to the weights of reducing inflows. The method uses the combination of an improved Bottleneck control method and a path guidance method based on journeyevents and shows that the vehicle delay at a trunk road can be greatly reduced and the adjustment efficiency is accelerated based on a VISSIM simulation result.

The invention relates to a design method of length from a left turn U-turn intersection to a stop line based on a traffic wave theory. The design method comprises the following steps: acquiring related traffic flow data through a manual counting method, calculating the wave velocity of a concentrated wave at the intersection with intersection left turn traffic volume and left turn traffic densityby utilizing a traffic flow fluctuation theory, finding the maximum queue length of upstream left-turn vehicles according to the distance concentrated and swept by the concentrated wave at the upstream of the intersection and taking the length as the distance from a U-turn lane to the stop line. The design method of the length from the left turn U-turn intersection to the stop line based on the traffic wave theory, provided by the invention, has the benefits that the blank in the design aspect of the length from the left turn U-turn intersection in the U-turn inside the intersection to the stop line is made up, the influence of T-turn vehicles on the left turn vehicles is effectively reduced, the intersection congestion can be reduced, the diversion conflict between left turn U-turn and left turn on a same lane can be reduced as much as possible, the influence of pedestrians on a crosswalk on the left turn U-turn vehicles is reduced, the operation efficiency and the safety of the intersection are improved, and the intersection traffic capacity is improved.

The invention discloses an intersection traffic state parameter estimation method and system based on multi-source data. The method comprises the following steps: building a vehicle delay model according to a traffic wave theory, and building a vehicle travel time model of a flow direction level according to the speed distribution characteristics of a vehicle; enabling a fixed-point detector to detect and obtain the flow of the road section entrance, and determining the number of vehicles arriving at the road section entrance; determining a traffic flow steering ratio of a road section by setting a virtual travel line according to a vehicle track acquired by a mobile detector; determining Bayesian networks of different flow directions according to the vehicle travel time model, the number of arrival vehicles and the traffic flow steering ratio; and solving the Bayesian network and determining the maximum queuing length and the average travel time of the vehicles in different flow directions. According to the embodiment of the invention, the vehicle track data and the fixed-point detector data are combined, and the parameter estimation method fusing the traffic wave theory and statistical analysis is established, so that the accuracy of traffic state parameter estimation is effectively improved.

The invention discloses an arterial coordination control method based on the traffic wave under the road section construction area background. The method includes the following steps of firstly, establishing a traffic wave model capable of reflecting features of a construction area; secondly, calculating parking delay of each crossing under the road section construction area background; thirdly, establishing a dual-target arterial coordination model with the main target of the minimum coordination phase parking delay and the auxiliary target of the minimum crossing parking delay under the constraint condition of no overflow of coordination phase queueing vehicles. Compared with the prior art, the method has the advantages that the influences on the vehicle speed probability distribution, arrival rate and queueing vehicle length and time in the presence of the construction area are sufficiently considered, and the arterial coordination model based on the traffic wave under the road section construction area background is established. By means of the method, the more accurate arterial coordination result is obtained, the traffic delay caused by the construction area is reduced as much as possible, and the traffic capacity of a construction area road section is effectively improved.

The invention provides a key intersection and adjacent intersection traffic signal control method, the key intersection adopts a one-way full-pass control method, and the adjacent intersection of thekey intersection adopts a three-turning traffic flow synchronization control method; and the release time of the adjacent intersection is determined by calculating the phase difference between the keyintersections and the adjacent intersections. The release duration is calculated by using a traffic wave correlation theory, so that a motorcade entering the entrance lane of the key intersection ateach adjacent intersection passes through the key intersection without stopping. The signal control method established by the invention is simple and easy to implement, and a simulation result shows that the signal control method can effectively prevent and improve the congestion condition of the key intersection, avoids the propagation and diffusion of congestion, and makes contribution to the smooth operation of the whole road network.

The invention relates to a hybrid bicycle traffic wave calculation method based on spatial awareness, and belongs to the technical field of transportation. According to the hybrid bicycle traffic wavecalculation method provided by the invention, by means of a hybrid traffic flow model based on spatial awareness, spatial ratios under different hybrid bicycle traffic states are analyzed, and hybridbicycle density and flow rate are determined, so that a hybrid bicycle traffic wave velocity is calculated through a cellular transmission model. By adoption of the hybrid bicycle traffic wave calculation method provided by the invention, the limitation that the assumption is too ideal when the operation of multi-strand bicycle flow is simulated by the previous methods, such that the isotropic traffic flow phenomenon cannot be better simulated, is overcome, and the hybrid bicycle traffic wave calculation precision is improved.

The invention relates to a method for predicting vehicle delay through lane division in real time based on IQA, and belongs to the technical field of intelligent transportation. The invention constructs an IQA delay polygon based on a method for predicting the queue length through lane division in real time and the traffic wave theory, and predicts the vehicle delay through the lane division in real time. By predicting IQA in advance, the defect that the real-time data is difficult to obtain when IQA is used for delay calculation in the past is made up, and the accuracy of the delay calculation is improved. According to the method for predicting vehicle delay through lane division in real time based on IQA, vehicle delay information can be obtained in advance by lane division, and passivedelay estimation is changed into active delay prediction, thereby facilitating the signal optimization design for relevant intersections or crowded roads in advance, so that the purpose of alleviatingthe traffic congestion and improving the travel environment can be achieved.

The invention provides a method for determining a traffic state of an urban intersection. Starting from a traffic wave theory, the method refinedly redefines the boundary of traffic states at an intersection by introducing the concepts of a passing rate, a traffic jam rate, and comprehensive action results, and solves the roughness of the current traffic state discriminant indicators of various intersections. In addition, the method provides a systematic, complete and implementable technical solution from concept description, theoretical characterization and method proposal.

The invention discloses an inferior quality repeater measurement method and device as well as a signal measurement terminal, belonging to the technical field of wireless communication. The inferior quality repeater measurement method comprises the following steps: firstly, looking up telephone traffic distribution data of an inferior quality repeater according to signal receiving quality; then looking up a telephone traffic wave crest of the telephone traffic distribution data of the inferior quality repeater; and finally, determining the position of the inferior quality repeater according to time advance corresponding to the telephone traffic wave crest. According to the inferior quality repeater measurement method, the inferior quality repeater and a non-inferior quality repeater can be distinguished through the signal receiving quality and the inferior quality repeater is identified by virtue of the signal receiving quality, so that the identification accuracy is ensured; the telephone traffic wave crest is identified through a time advance sliding window so that the identification precision of the telephone traffic wave crest is ensured and an actual position of the inferior quality repeater can be accurately looked up; and telephone traffic conditions of all the repeaters can be analyzed and the applicable range is wide.

The invention provides a road bottleneck section identification and traffic jam propagation early warning system and method. The wireless communication equipment detection unit collects a mac addressof wireless communication equipment in a vehicle, records a corresponding timestamp, packages the mac address, the timestamp and position information of the wireless communication equipment detectionunit, and sends packaged data to the data processing center unit. A data processing center unit analyzes and calculates the data sent by the wireless communication equipment detection unit to obtain the average vehicle speed of the road section in a preset time period, and identifies the bottleneck road section of the road; after the bottleneck road section is recognized, congestion propagation ofthe bottleneck road section is predicted on the basis of the traffic fluctuation theory, and a control command is sent to the early warning publishing unit; and the early warning publishing unit publishes congestion early warning prompt information according to the received control instruction. According to the invention, the road traffic state can be detected to identify the road bottleneck section, the traffic jam propagation of the bottleneck section can be predicted, and the traffic jam early warning can be issued to the vehicles at the upstream of the bottleneck section in time.

The invention relates to a signal control period division method based on trajectory data. The method comprises the following steps: S1, obtaining a relationship between the wave velocity and the flowof a concentrated wave based on a basic relationship among three parameters, namely a traffic wave theory, a Green-Hilbert linear model and a flow density velocity; S2, superposing the trajectory data of the same intersection in the same time period of multiple days to obtain input data; S3, based on the input data, a speed threshold division method and a kinetic equation, obtaining the wave velocity of the concentrated wave; and S4, clustering the wave velocity of the concentrated wave, and dividing a signal control time period based on the relationship between the wave velocity of the concentrated wave and the flow. Compared with the prior art, the operation efficiency and the safety level of the signal control intersection are improved, and the installation and maintenance cost of a fixed detector is reduced.

The invention discloses a self-adaptive signal control method and system in an intelligent network connection environment. The method comprises the following steps: acquiring trajectory data of a vehicle; acquiring traffic signal lamp information; according to the track data and the traffic signal lamp information, on the basis of a traffic wave model, obtaining real-time queuing information updated after the vehicle is queued when arriving at the intersection; constructing a dynamic planning model; according to the obtained dynamic planning model, obtaining a corresponding optimal phase green light duration; and controlling a traffic signal lamp to carry out traffic signal indication according to the obtained optimal phase green light duration of the corresponding state stage. According to the self-adaptive signal control method in the intelligent network connection environment, the self-adaptive signal control method supporting real-time response to traffic demand changes is provided, meanwhile, the normalized traffic control requirement is met, on the basis of a signal timing mechanism, the green light phase duration is optimally distributed in a staged mode, space-time resources are fully utilized, and the traffic control efficiency is improved. And the overall operation efficiency of the intersection is maximized.

The invention provides a traffic accident space-time influence range estimation method considering multiple congestion levels. The method comprises the following steps: constructing a space-time congestion level map by using speed data provided by a floating car, respectively obtaining speeds sj, m at a road section j and a time interval m under the condition of no accident and after the accident, and calculating a congestion level of each space-time cell according to the speeds and the speeds sj, m based on the number of congestion levels, a basic rule which should be met by the shape of a space-time area influenced by an accident is set according to a traffic wave propagation rule, and establishing an integer programming optimization model of a traffic accident influence range according to the basic rule, a constraint condition and an objective function, and solving the integer programming optimization model to obtain the optimized congestion level of each space-time cell. According to the method, a plurality of congestion levels can be distinguished, and the accuracy and precision of estimation are improved. The estimation result meets the propagation law of traffic waves, and the reasonability of the estimated space-time influence range is ensured.

The embodiment of the invention provides a road operation condition determination method and device, equipment and a storage medium, and the method comprises the steps: obtaining an image of a to-be-monitored road, wherein the image is obtained by shooting the monitored road; obtaining the number of vehicles of the to-be-monitored road, and dividing the to-be-monitored road into an uplink road anda downlink road based on the image and the number of vehicles of the to-be-monitored road; obtaining the number of vehicles on the ascending road and the number of vehicles on the descending road, and determining a target domain value based on the number of vehicles on the road to be monitored, the number of vehicles on the ascending road, the number of vehicles on the descending road and the traffic waves on the road to be monitored; when the vehicle number of the to-be-monitored road is greater than the target threshold, determining that the to-be-monitored road is congested.

The invention relates to the technical field of industrial control safety, in particular to a safety detection method based on self-adaptive traffic control. At present, most of active fingerprint detection technologies adopt a multi-task mode for scanning detection, and limit the traffic of introduced detection packets in a mode of limiting the number of multiple processes or multiple threads, and the control granularity is not accurate enough and has no prospectiveness only through a method of limiting the number of processes or threads. The method comprises the steps of self-adaptive scheduling, traffic prediction and network traffic real-time monitoring. The traffic prediction specifically comprises the following steps: 1, data cleaning; 2, feature selection; 3, model establishment; and 4, model training. The equipment fingerprint detection realized based on the method has the advantages of no interference to the service traffic of an industrial control system, no traffic wave crest and stable traffic velocity.

The present invention provides a method for controlling the traffic flow time of road nodes based on the traffic fluctuation theory, comprising the steps of: S1: the calculation model of the average vehicle speed of the downstream intersection established according to the traffic fluctuation theory; S2: real-time collection of two adjacent intersections The length L of the target road section between the intersections and the intersection length D of the downstream intersection; S3: Collect the vehicle speed information of the target road section between two adjacent intersections in real time, and calculate the average vehicle speed v of the target road section 1 ; S4: Calculate the average vehicle speed v at the downstream intersection of the target section 2 ; S5: Calculate the actual travel time t of the traffic flow on the target road section 0 and the maximum transit time of traffic flow t m ; S6: judge t 0 <t m Whether it is established, if not established, then adjust the traffic flow time of the target road section; the present invention avoids the overflow of the target road section vehicle flow to the upstream intersection, reduces the time cost and fuel cost caused by congestion, and improves the traffic efficiency of urban roads.