61 results about "Traffic wave" patented technology

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 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 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 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 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 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.

The present invention relates to a signal control period division method based on trajectory data, comprising the following steps: Step S1: Based on the basic relationship of traffic wave theory, Greenhill linear model and the three parameters of flow density and velocity, the relationship between the wave velocity and the flow of the assembled wave is obtained ;Step S2: Obtain the input data by superimposing the trajectory data of the same intersection for many days and the same time period; Step S3: Obtain the wave velocity of the assembly wave based on the input data, the speed threshold division method and the dynamic equation; Step S4: Calculate the wave velocity of the assembly wave Carry out clustering, and divide the signal control period based on the relationship between the wave velocity of the build-up wave and the flow rate. Compared with the existing technology, it not only improves the operational efficiency and safety level of the signal-controlled intersection, but also saves the installation and maintenance costs of fixed detectors.