10 results about "Saturation flow rate" patented technology

The application provides a traffic signal optimization method based on parameter calibration and improved Webster timing method, the method comprising: arranging detection coils in each lane in front of a stop line at an intersection, collecting vehicle passing information and storing locally; based on traffic flow theory analysis, calibrating saturated headway and calculating saturated flow of each lane according to the vehicle passing information, reducing the influence of oversaturated traffic flow on signal timing; for phase overlap and stage secondary release, the concept of phase residual flow ratio is proposed to solve the adaptation problem of Webster timing method under the signal timing requirements of the phase overlap and the stage secondary release; in the signal timing self-optimization link, if the signal timing meets the minimum green constraint relationship, the signal timing ends; if the signal timing does not meet the minimum green constraint relationship, the minimum green adjustment process is entered; when real-time optimization is performed, the updated signal timing is executed in the next cycle and the vehicle passing information is recorded again; when timing optimization is performed, adjustment is performed within a certain fixed time period based on historical data. The problems of unreasonable setting of basic parameters and limited use of traditional timing methods in actual application scenarios are solved, and a fast, accurate and stable traffic signal adaptive optimization system is established.

The invention discloses a method for measuring and calculating the maximum signal period of a signal control intersection based on road traffic organization and traffic flow fusion research and judgment, and belongs to the field of urban road traffic signal control. Firstly, intersection static channelization and traffic organization data and dynamic traffic flow data are fused. Secondly, the effective saturation flow rate of each lane is calculated through the quantization correction coefficient; and finally, embedding the average correction factor reflecting the overall static condition level of the intersection into an innovative formula, and calculating to obtain a recommended maximum period. According to the method, the signal control parameters are accurately matched with the'congenital conditions' of the intersection, the traffic potential can be fully excavated, and the green light utilization rate and the overall operation efficiency are improved.

The invention relates to a road network saturation flow detection method based on a microscopic simulation platform. The method comprises the following steps: S1, constructing a road network model in the microscopic simulation platform; s2, acquiring traffic density and traffic flow of each road section at different moments; s3, fitting to obtain a flow-density curve of each road section; s4, obtaining a flow distribution target of each road section; s5, generating an initial flow sequence of each road section; s6, the simulation flow of each road section is obtained, the difference value between the simulation flow of each road section and the flow distribution target is calculated to serve as the first fitness of each road section, and the sum of the first fitness of each road section serves as the total fitness value; s7, judging whether an iteration exit condition is met or not, if yes, executing the step S8, and otherwise, updating the flow sequence of each road section and returning to the step S6; and S8, generating the saturation flow of the road to be measured and the congestion degree of each road section. Compared with the prior art, the method has the advantages of efficiently and accurately solving the road network saturation flow demand under the condition of no complete historical data and the like.

The invention provides an AIS data-based busy water area macroscopic fundamental diagram acquisition method and system, an electronic device and a storage medium, and the method comprises the steps: constructing a water area macroscopic fundamental diagram with a water area ship cumulant as a state index and a water area boundary outflow as a performance index through mining ship automatic identification system data; forming a time sequence capable of reflecting the number of ships in the water area and the outflow efficiency; associating the two sequences to generate scatter data representing a macroscopic relationship; automatically dividing the scattered points into clusters corresponding to three typical states of free flow, saturation flow and congestion flow by using a clustering analysis technology; piecewise linear fitting is carried out on data in each state cluster, and a trapezoidal macroscopic fundamental diagram model with a clear ascending section, a stable section and a descending section is constructed; and a series of key characteristic parameters such as a critical inflection point of sign state transition, saturation flow representing the maximum traffic capacity and a slope reflecting the efficiency change rate are extracted, so that conversion from original data to a macroscopic cognitive model is completed.

The application provides a method for calculating saturation of road intersection import direction, comprising: obtaining real-time vehicle quantity and vehicle speed of each import lane stop line position of road intersection; obtaining corresponding signal light color of each import lane of road intersection; establishing vehicle speed record list corresponding to current signal period, counting total vehicle quantity, and recording green light duration and yellow light duration; calculating average vehicle speed of import lane vehicle of road intersection, and comparing with maximum historical average vehicle speed; calculating import lane saturation flow of road intersection; calculating traffic flow of import lane of road intersection; and calculating saturation of road intersection import direction. The application can realize real-time, accurate and automatic calculation of import lane saturation value through vehicle detector, traffic signal control machine and other devices.

The application provides an AIS data-based busy water area macroscopic basic graph acquisition method and system, an electronic device and a storage medium. By mining ship automatic identification system data, a water area macroscopic basic graph is constructed with water area ship cumulative amount as a state index and water area boundary outflow as a performance index, and a time sequence sequence capable of reflecting the number of ships in the water area and the outflow efficiency is formed. The two sequences are associated to generate scatter data representing the macroscopic relationship. Then, clustering analysis technology is used to automatically divide the scatter points into clusters corresponding to three typical states of free flow, saturated flow and congested flow. The data in each state cluster is separately subjected to piecewise linear fitting to construct a trapezoidal macroscopic basic graph model with a clear rising section, a stable section and a falling section. A series of key characteristic parameters such as a critical inflection point indicating state transition, a saturated flow representing the maximum traffic capacity and a slope reflecting the efficiency change rate are extracted, thereby completing the transformation from the original data to the macroscopic cognitive model.

The application provides a kind of intersection traffic flow state identification method and traffic signal control equipment, it is related to intelligent transportation technical field.The application is according to each kind of traffic flow turning at target intersection, according to the maximum saturation flow rate of this kind of traffic flow turning and the actual signal control traffic data of this kind of traffic flow turning in current signal control period, the actual saturation of this kind of traffic flow turning in current signal control period is calculated, and the historical traffic flow state score of the last signal control period of this kind of traffic flow turning in current signal control period is combined, according to the target traffic flow state score rule adapted to the target intersection, the actual traffic flow state score of this kind of traffic flow turning in current signal control period is calculated to identify traffic flow state, so as to deeply consider the influence of traffic flow fluctuation in intersection traffic flow state identification process, ensure that the final traffic flow state identification result can accurately reflect the overall change trend of real intersection traffic flow state in time dimension level.

This invention discloses an algorithm-based method for evaluating the utilization efficiency of green lights in urban road traffic, comprising the following steps: obtaining a standardized dataset; performing lane matching for vehicles to obtain vehicle passage records for each lane; dividing the time interval and calculating the average flow rate of each lane within the target time period; calculating the saturation flow rate of each lane; obtaining the corrected saturation flow rate of each lane; using an improved Kuramoto model to output the total flow rate ratio of signal phases; obtaining low flow rate ratio scenarios and high flow rate ratio scenarios; using the Webster algorithm to calculate the signal cycle and the green light time of each signal phase, constructing an optimization model with the goal of minimizing the total delay at the intersection, and optimizing the solution for the signal cycle and the green light time of each signal phase; outputting signal timing parameters and corresponding traffic operation evaluation results to improve green light utilization efficiency, reduce traffic delay, and enhance the capacity and smoothness of the intersection.

The invention provides a water flow valve intelligent control method fusing a mechanism and a neural network, and relates to the technical field of industrial automation control. The method comprises the steps that flow and inlet pressure of a flow valve at different opening degrees in different system states are collected; based on the collected data, constructing and training a saturation opening degree prediction model, a saturation flow prediction model and an opening degree prediction model based on mixing of a mechanism and a neural network; when monitoring that the target flow is changed, judging whether the target flow is greater than saturated flow or not by using a saturated flow prediction model; if not, predicting a target opening degree by using an opening degree prediction model based on mixing of a mechanism and a neural network, and setting the opening degree of the flow valve as the predicted target opening degree; after the flow is stable, if the difference between the current flow and the target flow is smaller than or equal to a set threshold value, the PID control mode is directly used for fine adjustment so as to reach the target flow. In this way, rapid and high-precision control over the cooling water flow in the continuous casting process can be achieved.

The application discloses a real-time lane traffic capacity calculation method and system based on radar and video fusion. The method comprises the following steps: acquiring video image data and radar detection data; performing data fusion on the video image data and the radar detection data to obtain relative space-time information of each vehicle relative to a crossroad, and obtaining absolute space-time information of all vehicles at the crossroad according to the relative space-time information; acquiring traffic timing information and map information of the crossroad, and obtaining a saturation flow rate of a jth lane in a phase i and a stage green ratio of the jth lane in the phase i or a passable time proportion of the jth lane in the phase i according to the traffic timing information, the map information and the absolute space-time information; and obtaining a traffic capacity of the jth lane in the phase i according to the saturation flow rate of the jth lane in the phase i and the stage green ratio of the jth lane in the phase i.