An efficient data communication method for highway electromechanical systems

Abstract

The present invention relates to the field of data communication technology, and proposes an efficient data communication method for a highway electromechanical system, including: collecting the number of vehicles in motion, the speed of the vehicles, and the distance between adjacent vehicles; determining the speed stability of the target vehicle and marking abnormal vehicles, and determining the complexity of traffic conditions; marking the risk radar speed meter at each collection moment and the risk radar speed meter group at the same collection moment, determining the moment importance of the collection moment, dividing all collection moments into different time periods, determining the focus of time periods, risk time periods, and normal time periods; according to the complexity of traffic conditions at all collection moments of the radar speed meter in the normal time period and the focus of the normal time period, respectively transmitting and communicating the data collected by the radar speed meter in the risk time period and the normal time period. The present invention aims to solve the problem that the transmission of electromechanical data on highways cannot balance compression efficiency and data accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of data communication, and in particular to a high-efficiency data communication method for a highway electromechanical system. Background Art

[0002] The electromechanical system of highways is an auxiliary system for the traffic function of road facilities, mainly including subsystems such as communication systems, traffic monitoring systems, electromechanical systems, toll collection systems, and power distribution and lighting systems. Among them, the communication system and traffic monitoring system collect and transmit data through a large number of vehicle sensors, cameras, and fiber-optic communication equipment to monitor and analyze traffic flow and vehicle driving conditions in real time. The electromechanical system can adjust traffic signals according to traffic flow and vehicle driving conditions to avoid or reduce traffic congestion. The traffic monitoring system in the electromechanical system of highways transmits traffic data through the communication network, while the vehicle sensors and cameras on the road continuously collect a large amount of data, which will occupy a large amount of bandwidth, reduce the speed of data transmission, and cannot guarantee the timeliness of real-time monitoring of traffic flow and vehicle driving conditions.

[0003] Traffic data collected in real time can be compressed and then transmitted. However, the accuracy of the compressed traffic data is often affected by the improvement of compression efficiency, resulting in insufficient accuracy of traffic data under complex road conditions. Lossless compression that ensures the accuracy of traffic data often has low compression efficiency. Summary of the invention

[0004] The present invention provides an efficient data communication method for a highway electromechanical system to solve the problem that the transmission of highway electromechanical data cannot balance the compression efficiency and data accuracy. The technical solution adopted is as follows:

[0005] An embodiment of the present invention provides an efficient data communication method for a highway electromechanical system, the method comprising the following steps:

[0006] The number of vehicles traveling at the current time and a preset number of collection times before, the speed of the vehicles and the distance between adjacent vehicles are collected from different radar speed guns on the highway;

[0007] Any vehicle collected by the same radar speed gun at any collection time is recorded as a target vehicle, and the speed stability of the target vehicle is determined and abnormal vehicles are marked according to the speed of vehicles collected by the same radar speed gun at the same collection time and the distance between adjacent vehicles of the target vehicle, and the complexity of the traffic conditions in the same radar speed gun measurement range at the same collection time is determined according to the number of all vehicles in the same radar speed gun measurement range at the same collection time, the speeds of all abnormal vehicles and the speed stability of all abnormal vehicles;

[0008] Mark the risk radar speed gun at each collection moment and the risk radar speed gun group at the same collection moment according to the complexity of traffic conditions; determine the moment importance of the collection moment according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection moment, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups; divide all collection moments into different time periods; determine the focus of the time period according to the number of risk radar speed guns at all collection moments in the time period and the moment importance; and determine the risk time period and normal time period according to the focus;

[0009] According to the complexity of traffic conditions at all collection moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, as well as the data collected by the radar speed gun in the risk time period and the normal time period, the data collected by the radar speed gun in the risk time period and the normal time period are transmitted and communicated respectively.

[0010] Further, the method of determining the speed stability of the target vehicle and marking the abnormal vehicle according to the speed of the vehicle collected by the same radar speed meter at the same collection time as the target vehicle and the distance between the adjacent vehicles of the target vehicle includes the following specific methods:

[0011] The average value of the speeds of all vehicles different from the target vehicle collected at the same collection time and the same position as the target vehicle is recorded as the relative speed of the target vehicle, and the absolute value of the difference between the relative speed of the target vehicle and the speed of the target vehicle is recorded as the relative speed difference of the target vehicle;

[0012] The average of the distances of all adjacent vehicles collected at the same collection time and location as the target vehicle is recorded as the relative distance of the target vehicle;

[0013] Determine the speed stability of the target vehicle according to the relative distance and relative speed difference of the target vehicle, wherein the speed stability of the target vehicle is positively correlated with the relative distance of the target vehicle and negatively correlated with the relative speed of the target vehicle;

[0014] Flag abnormal vehicles based on the speed stability of target vehicles.

[0015] Further, the specific method of marking an abnormal vehicle according to the speed stability of the target vehicle includes:

[0016] When the normalized value of the vehicle speed stability of the target vehicle is less than a preset stability threshold, the target vehicle is marked as an abnormal vehicle.

[0017] Furthermore, the method for determining the complexity of the traffic condition is:

[0018] The ratio of the speed of the abnormal vehicle to the vehicle speed stability is recorded as the first ratio of the abnormal vehicle, and the cumulative sum of the first ratios of all abnormal vehicles in the same radar speed meter measurement range at the same collection time is recorded as the second ratio in the same radar speed meter measurement range at the same collection time;

[0019] The product of the number of all vehicles within the same radar speed gun measurement range at the same collection time and the second ratio within the same radar speed gun measurement range at the same collection time is recorded as the traffic condition complexity within the same radar speed gun measurement range at the same collection time.

[0020] Furthermore, the specific method of marking the risk radar speed gun at each collection moment and the risk radar speed gun group at the same collection moment according to the complexity of the traffic conditions includes:

[0021] When the complexity of the traffic condition is greater than the preset risk threshold, the radar speed gun at the collection time corresponding to the complexity of the traffic condition is marked as a risk radar speed gun;

[0022] All adjacent risk radar speed guns at the same acquisition time are recorded as a risk radar speed gun group.

[0023] Further, the moment importance of the collection time is determined according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection time, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups, including the specific method of:

[0024] The product of the mean of the traffic condition complexity of all risk radar speed guns in the same risk radar speed gun group and the number of risk radar speed guns is recorded as the first product of the same risk radar speed gun group, and the cumulative sum of the first products of all risk radar speed gun groups is recorded as the first cumulative sum of the collection times corresponding to all risk radar speed gun groups;

[0025] The length of the highway between two different risk radar speed gun groups at the same acquisition time is recorded as the distance between the two different risk radar speed gun groups;

[0026] The product of the mean value of the distances of all different risk radar speed gun groups at the collection time and the first cumulative sum at the collection time is recorded as the time importance of the collection time.

[0027] Furthermore, the specific method of dividing all the acquisition moments into different time periods includes:

[0028] Using the APCA segmentation method, all acquisition moments are divided into different time periods according to their moment importance.

[0029] Further, the method of determining the focus of the time period according to the number of risk radar speed guns at all collection moments in the time period and the importance of the moments, and determining the risk time period and the normal time period according to the focus, includes the following specific methods:

[0030] When the same risk radar speed gun is a risk radar speed gun at consecutive collection moments, the time period consisting of all consecutive collection moments is recorded as the risk time period of the risk radar speed gun;

[0031] Calculate the focus of the time period, the calculation formula is:

[0032]

[0033] in, Indicates The focus of the time period; B represents the The number of risk radar speed guns at the first collection moment in a time period; Indicates The risk radar speed gun is in The number of acquisition moments marked as risky radar guns in a time period; Indicates The mean of the moment importance of all the collected moments in a time period; Indicates The number of acquisition moments in a time period; Indicates The risk radar speed gun is in The number of risk time periods corresponding to the time periods; represents the linear normalization function;

[0034] When the key attention degree is greater than the attention threshold, the time period corresponding to the key attention degree is marked as a risk time period; when the key attention degree is less than or equal to the attention threshold, the time period corresponding to the key attention degree is marked as a normal time period.

[0035] Further, according to the complexity of traffic conditions at all collection moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, as well as the data collected by the radar speed gun in the risk time period and the normal time period, the data collected by the radar speed gun in the risk time period and the normal time period are transmitted and communicated respectively, including the specific method of:

[0036] According to the complexity of traffic conditions at all acquisition moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, the optimal value of the compressed QP of the radar speed gun in the normal time period is determined, and the calculation formula is:

[0037]

[0038] in, Indicates A radar speed gun is located in The optimal value of compression QP for a normal time period; represents a first preset parameter; represents the second preset parameter; represents an exponential function with a natural constant as base; Indicates The focus of attention during a normal period of time; Indicates A radar speed gun is located in The average value of the traffic condition complexity at all sampling times in a normal time period;

[0039] Transmitting and communicating data collected by the radar speed gun during a normal time period according to the optimal value of the compressed QP of the radar speed gun during a normal time period;

[0040] The data collected by the radar speed gun during the risk period, including the number of vehicles on the road, the speed of the vehicles and the distance between adjacent vehicles, are directly transmitted and stored.

[0041] Further, the data collected by the radar speed gun in the normal time period is transmitted and communicated according to the optimal value of the compressed QP of the radar speed gun in the normal time period, including the specific method of:

[0042] The rounded value of the optimal compression QP value of the radar speed gun in the normal time period is used as the value of the parameter QP of the H.264 / AVC video coding standard, the number of vehicles in motion, the speed of the vehicles and the distance between adjacent vehicles collected by the radar speed gun in the normal time period are lossily compressed, the compressed data of the radar speed gun in the normal time period is obtained, and the compressed data of the radar speed gun in the normal time period is transmitted and stored.

[0043] The beneficial effects of the present invention are:

[0044] The present application analyzes the speed of the vehicle, marks abnormal vehicles, and further evaluates the complexity of the traffic conditions within the measurement range of the same radar speed gun at the same collection time based on the fact that the speed of the vehicle is relatively stable when traveling on the highway, but when the vehicle frequently changes lanes, overtakes, or exhibits unstable speed, the possibility of the vehicle having a traffic accident is greater and more attention needs to be paid. The complexity of the traffic conditions is obtained by further evaluating the complexity of the traffic conditions within the measurement range of the same radar speed gun at the same collection time. Then, the more consistent the traffic conditions within the measurement ranges of different risk radar speed guns in the same risk radar speed gun group are and the greater the complexity of the traffic conditions, the more important the data at the collection time corresponding to the risk radar speed gun group is. When compressing the data at the collection time corresponding to the risk radar speed gun group, the more it is necessary to ensure the accuracy of the data. The importance of the collection time is evaluated, all the collection times are divided into different time periods, and the risk time period and the normal time period are determined. Finally, according to the complexity of the traffic conditions at all collection times in the normal time period and the focus of attention in the normal time period, the data collected in the normal time period is lossily compressed and communicated, and the data collected in the normal time period is directly transmitted and communicated, so as to solve the problem that the transmission of electromechanical data on highways cannot balance the compression efficiency and data accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 A schematic flow chart of an efficient data communication method for a highway electromechanical system provided by an embodiment of the present invention;

[0047] Figure 2 A flowchart for obtaining an abnormal vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] See also Figure 1 , which shows a flow chart of an efficient data communication method for a highway electromechanical system provided by an embodiment of the present invention, the method comprising the following steps:

[0050] Step S001: collect the number of vehicles traveling at the current moment and a preset number of collection moments before, the speed of the vehicles, and the distance between adjacent vehicles from different radar speed guns on the highway.

[0051] The radar speed gun on the highway collects the number of vehicles traveling on the highway and within the measurement range of the radar speed gun and the speed of each vehicle, and at the same time, collects the distance between adjacent vehicles.

[0052] It is understandable that there are multiple radar speed guns installed on the highway, and each radar speed gun can collect the number of vehicles traveling on the highway and within the measurement range of the radar speed gun, the speed of the vehicles and the distance between adjacent vehicles; at the same time, the position of the radar speed guns installed on the highway is fixed, and the length of the highway between different radar speed guns is also fixed, so the length of the highway between different radar speed guns can be directly obtained.

[0053] Preferably, in one embodiment of the present application, when collecting the number of vehicles, the speed of vehicles, and the distance between adjacent vehicles, the time interval between the collection moments is 1 second, and the collection duration is 1 hour, that is, the number of vehicles, the speed of vehicles, and the distance between adjacent vehicles at all collection moments within an hour before the current moment are collected. In actual application, as other implementation methods, the implementer can decide the time interval and the collection duration of the collection moments according to the actual situation, and the present application does not impose any special restrictions.

[0054] So far, within the current time and the previous one hour, the number of vehicles traveling on the highway at different locations and different collection times, the speed of the vehicles, and the distance between adjacent vehicles are obtained.

[0055] Step S002: any vehicle collected by the same radar speed gun at any collection time is recorded as a target vehicle; based on the speed of vehicles collected by the same radar speed gun at the same collection time as the target vehicle, and the distance between adjacent vehicles of the target vehicle, the speed stability of the target vehicle is determined and abnormal vehicles are marked; based on the number of all vehicles within the measurement range of the same radar speed gun at the same collection time, the speeds of all abnormal vehicles, and the speed stability of all abnormal vehicles, the complexity of the traffic conditions within the measurement range of the same radar speed gun at the same collection time is determined.

[0056] Within the measurement range of each radar speed meter on the highway, the vehicle's speed is relatively stable under normal driving and it drives according to the speed limit. However, the personal habits and behaviors of drivers of different vehicles are different. When a vehicle has unstable speed performance such as frequent lane changes and overtaking, the possibility of a traffic accident is greater and more attention should be paid.

[0057] Any vehicle collected at the same location at any collection time is recorded as the target vehicle. The speed stability of the target vehicle is determined based on the speed of vehicles collected at the same collection time and location as the target vehicle, as well as the distance between the target vehicle and its adjacent vehicles.

[0058] It can be understood that any one of the collection moments includes the current moment.

[0059] The average of the speeds of all vehicles different from the target vehicle collected at the same collection time and location as the target vehicle is recorded as the relative speed of the target vehicle, and the absolute value of the difference between the relative speed of the target vehicle and the speed of the target vehicle is recorded as the relative speed difference of the target vehicle. The average of the distances of all adjacent vehicles collected at the same collection time and location as the target vehicle is recorded as the relative distance of the target vehicle.

[0060] The speed stability of the target vehicle is determined according to the difference between the relative vehicle distance and the relative speed of the target vehicle, wherein the speed stability of the target vehicle is positively correlated with the relative vehicle distance of the target vehicle and negatively correlated with the relative speed of the target vehicle.

[0061] It can be understood that the positive correlation and negative correlation in this application refer to the relationship between the independent variable and the dependent variable. The positive correlation means that the dependent variable increases (decreases) as the independent variable increases (decreases), which can be an additive relationship, a multiplicative relationship, etc.; the negative correlation means that the dependent variable decreases (increases) as the independent variable increases (decreases), which can be an inverse relationship, a subtractive relationship, etc.

[0062] Preferably, as an embodiment of the present application, the ratio of the relative vehicle distance to the relative speed difference of the target vehicle is recorded as the vehicle speed stability of the target vehicle.

[0063] In actual application, as another implementation method, the opposite of the relative speed of the target vehicle is used as the exponent, and the exponential power of the natural constant is used as the base, which is recorded as the first power value of the target vehicle, and the product of the relative distance of the target vehicle and the first power value is recorded as the speed stability of the target vehicle.

[0064] On the highway, vehicles in the same lane must maintain a certain distance between them, and their speeds must be within the speed range specified for that lane. Therefore, the greater the difference between the speed of the vehicle collected at the same collection time and position as the target vehicle and the speed of the target vehicle, and the greater the distance between the target vehicle and its adjacent vehicles, the more unsynchronized the movement of the target vehicle and its adjacent vehicles, the closer the traffic conditions when the target vehicle is traveling are to the limit state of traffic regulations, the more likely a traffic accident is to occur, and the more complex the traffic conditions are. At this time, the speed stability of the target vehicle is lower.

[0065] The normalized value of the vehicle speed stability of the target vehicle is compared with a stability threshold, and when the normalized value of the vehicle speed stability of the target vehicle is less than the stability threshold, the target vehicle is marked as an abnormal vehicle.

[0066] In this embodiment, the stability threshold is set to 0.5, and the abnormal vehicle acquisition flow chart is as follows: Figure 2 shown.

[0067] It should be noted that this embodiment uses the Z-Score standard normalization method to calculate the normalized value. In actual application, the implementer may use other methods in the prior art such as the maximum and minimum value normalization method, the sigmoid function, etc. to calculate the normalized value, which is not limited here.

[0068] The complexity of the traffic conditions within the same radar speed meter measurement range at the same collection time is determined according to the number of all vehicles, the speeds of all abnormal vehicles and the speed stability of all abnormal vehicles within the same radar speed meter measurement range at the same collection time.

[0069] Preferably, as an embodiment of the present application, the ratio of the speed of an abnormal vehicle to the vehicle speed stability is recorded as the first ratio of the abnormal vehicle, and the cumulative sum of the first ratios of all abnormal vehicles in the same radar speedometer measurement range at the same collection time is recorded as the second ratio in the same radar speedometer measurement range at the same collection time; the product of the number of all vehicles in the same radar speedometer measurement range at the same collection time and the second ratio in the same radar speedometer measurement range at the same collection time is recorded as the complexity of the traffic conditions in the same radar speedometer measurement range at the same collection time.

[0070] When the number of vehicles and the number of abnormal vehicles within the measuring range of the same radar speed gun at the same collection time are greater, the speed of the abnormal vehicles is greater, and the speed stability of the abnormal vehicles is smaller, the more vehicles and the number of vehicles with unstable speeds within the measuring range of the same radar speed gun at the same collection time are greater, the risk of accidents is greater, and the traffic conditions are more complicated. At this time, the traffic conditions are more complicated.

[0071] At this point, the complexity of the traffic conditions at the same acquisition time in the same radar speed meter measurement range is obtained.

[0072] Step S003, mark the risk radar speed gun at each collection moment and the risk radar speed gun group at the same collection moment according to the complexity of traffic conditions, determine the moment importance of the collection moment according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection moment, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups, and divide all collection moments into different time periods, determine the focus of the time period according to the number and moment importance of risk radar speed guns at all collection moments in the time period, and determine the risk time period and normal time period according to the focus.

[0073] When complex road conditions occur on the highway, the accident risk within the measurement ranges of several adjacent radar speed guns is often relatively high. Therefore, it is necessary to further analyze the measurement ranges of radar speed guns with continuous and complex traffic conditions.

[0074] The traffic condition complexity is compared with the risk threshold. When the traffic condition complexity is greater than the risk threshold, the radar speed gun at the acquisition time corresponding to the traffic condition complexity is marked as a risk radar speed gun. All adjacent risk radar speed guns at the same acquisition time are recorded as a risk radar speed gun group.

[0075] In this embodiment, the risk threshold value is 0.6.

[0076] The more consistent the traffic conditions within the measurement ranges of different risk radar speed guns in the same risk radar speed gun group are and the more complex the traffic conditions are, the more important the data at the collection time corresponding to the risk radar speed gun group is, and when compressing the data at the collection time corresponding to the risk radar speed gun group, the more it is necessary to ensure the accuracy of the data.

[0077] The temporal importance of the collection moment is determined according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection moment, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups.

[0078] The product of the mean of the traffic condition complexity of all risk radar speed guns in the same risk radar speed gun group and the number of risk radar speed guns is recorded as the first product of the same risk radar speed gun group, and the cumulative sum of the first products of all risk radar speed gun groups is recorded as the first cumulative sum of the collection moments corresponding to all risk radar speed gun groups; the length of the highway between two different risk radar speed gun groups at the same collection moment is recorded as the distance between the two different risk radar speed gun groups; the product of the mean of the distances of all different risk radar speed gun groups at the collection moment and the first cumulative sum at the collection moment is recorded as the moment importance of the collection moment.

[0079] Among them, the method for obtaining the length of the highway between two different risk radar speed gun groups is: select a risk radar speed gun from each of the two different risk radar speed gun groups, calculate the length of the highway between the two selected risk radar speed guns, and record the minimum value of the length of the highway between the two risk radar speed guns selected from the two different risk radar speed gun groups as the length of the highway between the two different risk radar speed gun groups.

[0080] When the length of the highway between the risk radar speed gun groups is longer, the different risk radar speed gun groups at the same collection time are more dispersed, the areas with complex traffic conditions are farther apart in space, and the range of influence of the areas with complex road conditions is wider. The data collected at the collection time corresponding to the risk radar speed gun group is more important. When compressing the data at the collection time corresponding to the risk radar speed gun group, it is more necessary to ensure the accuracy of the data. At this time, the importance of the collection time is greater.

[0081] The APCA segmentation method is used to divide the time periods composed of the collection moments according to the moment importance of all the collection moments, and all the collection moments are divided into different time periods.

[0082] Among them, using the APCA segmentation method to divide all the acquisition moments into different time periods is a well-known technology and will not be described in detail.

[0083] Traffic anomalies on highways are dynamic. The sections with abnormal traffic conditions in the same time period may be concentrated or scattered. Generally, drivers usually change lanes or adjust routes according to road conditions. Therefore, the traffic conditions on the same section will change over time. However, when a section is in abnormal traffic conditions for a long time in the same time period, it needs to be paid special attention to during that time period.

[0084] Determine the focus of a time period based on the number of risk radar speed guns at all collection moments in the time period and the importance of the moments.

[0085] When the same risk radar speed gun is a risk radar speed gun at consecutive collection moments, the time period composed of all consecutive collection moments is recorded as the risk time period of the risk radar speed gun.

[0086]

[0087] in, Indicates The focus of the time period; B represents the The number of risk radar speed guns at the first collection moment in a time period; Indicates The risk radar speed gun is in The number of acquisition moments marked as risky radar guns in a time period; Indicates The mean of the moment importance of all the collected moments in a time period; Indicates The number of acquisition moments in a time period; Indicates The risk radar speed gun is in The number of risk time periods corresponding to the time periods; represents the linear normalization function.

[0088] When the importance of all collection moments in a time period is greater, the number of collection moments marked as risk radar speed guns in the time period is greater relative to the number of collection moments in the time period, and the number of risk time periods corresponding to risk radar speed guns in the time period is smaller, the time periods with abnormal traffic conditions in the time period are more concentrated, and the longer the abnormality lasts, the time period needs more attention, and at this time, the time period has a greater degree of attention.

[0089] The key attention degree is compared with the attention threshold. When the key attention degree is greater than the attention threshold, the time period corresponding to the key attention degree is marked as a risk time period; when the key attention degree is less than or equal to the attention threshold, the time period corresponding to the key attention degree is marked as a normal time period.

[0090] In this embodiment, the value of the attention threshold is 0.4.

[0091] At this point, the risk time period and the normal time period are determined.

[0092] Step S004: based on the complexity of traffic conditions at all collection moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, as well as the data collected by the radar speed gun in the risk time period and the normal time period, the data collected by the radar speed gun in the risk time period and the normal time period are transmitted and communicated respectively.

[0093] According to the complexity of traffic conditions at all acquisition moments of the radar speed gun during the normal time period and the focus of attention during the normal time period, the optimal value of the compressed QP of the radar speed gun during the normal time period is determined.

[0094]

[0095] in, Indicates A radar speed gun is located in The optimal value of compression QP for a normal time period; represents the first preset parameter. In this embodiment, the value of the first preset parameter is 10; represents the second preset parameter. In this embodiment, the value of the second preset parameter is 20; represents an exponential function with a natural constant as base; Indicates The focus of attention during a normal period of time; Indicates A radar speed gun is located in The average of the traffic condition complexity at all sampling moments in a normal time period.

[0096] When the traffic conditions at all collection moments of the radar speed gun in the normal time period are more complex and the focus of attention in the normal time period is greater, the traffic conditions within the detection range of the radar speed gun are more complex. When compressing the data at the collection moments corresponding to the risk radar speed gun group, it is more necessary to ensure the accuracy of the data and retain more detailed information. At this time, the optimal compression QP value of the radar speed gun in the normal time period is smaller.

[0097] The rounded value of the optimal compression QP value of the radar speed gun in the normal time period is used as the value of the parameter QP of the H.264 / AVC video coding standard, the number of vehicles in motion, the speed of the vehicles and the distance between adjacent vehicles collected by the radar speed gun in the normal time period are lossily compressed, the compressed data of the radar speed gun in the normal time period is obtained, and the compressed data of the radar speed gun in the normal time period is transmitted and stored.

[0098] The data collected by the radar speed gun during the risk period, including the number of vehicles on the road, the speed of the vehicles and the distance between adjacent vehicles, are directly transmitted and stored.

[0099] Among them, the parameter QP of the H.264 / AVC video coding standard is used to control the QStep quantization step size in the encoding process, which can affect the compression efficiency and quality of the video. The smaller the parameter QP, the better the detailed information of the compressed data is retained, and the greater the accuracy of the compressed data. Using the H.264 / AVC video coding standard for data compression is a well-known technology and will not be repeated here.

[0100] At this point, efficient data communication of highway electromechanical systems has been achieved.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An efficient data communication method for a highway electromechanical system, characterized in that: The method comprises the following steps: The number of vehicles traveling at the current time and a preset number of collection times before, the speed of the vehicles and the distance between adjacent vehicles are collected from different radar speed guns on the highway; Any vehicle collected by the same radar speed gun at any collection time is recorded as a target vehicle, and the speed stability of the target vehicle is determined and abnormal vehicles are marked according to the speed of vehicles collected by the same radar speed gun at the same collection time and the distance between adjacent vehicles of the target vehicle, and the complexity of the traffic conditions in the same radar speed gun measurement range at the same collection time is determined according to the number of all vehicles in the same radar speed gun measurement range at the same collection time, the speeds of all abnormal vehicles and the speed stability of all abnormal vehicles; Mark the risk radar speed gun at each collection moment and the risk radar speed gun group at the same collection moment according to the complexity of traffic conditions; determine the moment importance of the collection moment according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection moment, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups; divide all collection moments into different time periods; determine the focus of the time period according to the number of risk radar speed guns at all collection moments in the time period and the moment importance; and determine the risk time period and normal time period according to the focus; According to the complexity of traffic conditions at all collection moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, as well as the data collected by the radar speed gun in the risk time period and the normal time period, the data collected by the radar speed gun in the risk time period and the normal time period are transmitted and communicated respectively.

2. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The method of determining the speed stability of the target vehicle and marking the abnormal vehicle according to the speed of the vehicle collected by the same radar speed meter at the same collection time as the target vehicle and the distance between the adjacent vehicles of the target vehicle includes the following specific methods: The average value of the speeds of all vehicles different from the target vehicle collected at the same collection time and the same position as the target vehicle is recorded as the relative speed of the target vehicle, and the absolute value of the difference between the relative speed of the target vehicle and the speed of the target vehicle is recorded as the relative speed difference of the target vehicle; The average of the distances of all adjacent vehicles collected at the same collection time and location as the target vehicle is recorded as the relative distance of the target vehicle; Determine the speed stability of the target vehicle according to the difference between the relative vehicle distance and the relative speed of the target vehicle, wherein the speed stability of the target vehicle is positively correlated with the relative vehicle distance of the target vehicle and negatively correlated with the relative speed of the target vehicle; Flag abnormal vehicles based on the speed stability of target vehicles.

3. The high-efficiency data communication method for a highway electromechanical system according to claim 2, characterized in that: The specific method of marking an abnormal vehicle according to the speed stability of the target vehicle includes: When the normalized value of the vehicle speed stability of the target vehicle is less than a preset stability threshold, the target vehicle is marked as an abnormal vehicle.

4. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The method for determining the complexity of the traffic condition is: The ratio of the speed of the abnormal vehicle to the vehicle speed stability is recorded as the first ratio of the abnormal vehicle, and the cumulative sum of the first ratios of all abnormal vehicles in the same radar speed meter measurement range at the same collection time is recorded as the second ratio in the same radar speed meter measurement range at the same collection time; The product of the number of all vehicles within the same radar speed gun measurement range at the same collection time and the second ratio within the same radar speed gun measurement range at the same collection time is recorded as the traffic condition complexity within the same radar speed gun measurement range at the same collection time.

5. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The specific method of marking the risk radar speed gun at each collection moment and the risk radar speed gun group at the same collection moment according to the complexity of the traffic conditions includes: When the complexity of the traffic condition is greater than the preset risk threshold, the radar speed gun at the collection time corresponding to the complexity of the traffic condition is marked as a risk radar speed gun; All adjacent risk radar speed guns at the same acquisition time are recorded as a risk radar speed gun group.

6. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The method of determining the time importance of the collection time according to the complexity of traffic conditions of all different risk radar speed gun groups at the collection time, the number of risk radar speed guns contained in the risk radar speed gun group, and the length of the highway between different risk radar speed gun groups includes: The product of the mean of the traffic condition complexity of all risk radar speed guns in the same risk radar speed gun group and the number of risk radar speed guns is recorded as the first product of the same risk radar speed gun group, and the cumulative sum of the first products of all risk radar speed gun groups is recorded as the first cumulative sum of the collection times corresponding to all risk radar speed gun groups; The length of the highway between two different risk radar speed gun groups at the same acquisition time is recorded as the distance between the two different risk radar speed gun groups; The product of the mean value of the distances of all different risk radar speed gun groups at the collection time and the first cumulative sum at the collection time is recorded as the time importance of the collection time.

7. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The specific method of dividing all the acquisition moments into different time periods includes: Using the APCA segmentation method, all acquisition moments are divided into different time periods according to their moment importance.

8. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The method of determining the focus of the time period according to the number of risk radar speed guns at all collection moments in the time period and the importance of the moments, and determining the risk time period and the normal time period according to the focus, includes the following specific methods: When the same risk radar speed gun is a risk radar speed gun at consecutive collection moments, the time period consisting of all consecutive collection moments is recorded as the risk time period of the risk radar speed gun; Calculate the focus of the time period, the calculation formula is: in, Indicates The focus of the time period; B represents the The number of risk radar speed guns at the first collection moment in a time period; Indicates The risk radar speed gun is in The number of acquisition moments marked as risky radar guns in a time period; Indicates The mean of the moment importance of all the collected moments in a time period; Indicates The number of acquisition moments in a time period; Indicates The risk radar speed gun is in The number of risk time periods corresponding to the time periods; represents the linear normalization function; When the key attention degree is greater than the attention threshold, the time period corresponding to the key attention degree is marked as a risk time period; when the key attention degree is less than or equal to the attention threshold, the time period corresponding to the key attention degree is marked as a normal time period.

9. The high-efficiency data communication method for a highway electromechanical system according to claim 1, characterized in that: The method of transmitting and communicating the data collected by the radar speed gun in the risk time period and the normal time period respectively according to the complexity of the traffic conditions at all collection moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, as well as the data collected by the radar speed gun in the risk time period and the normal time period, includes the following specific methods: According to the complexity of traffic conditions at all acquisition moments of the radar speed gun in the normal time period and the focus of attention in the normal time period, the optimal value of the compressed QP of the radar speed gun in the normal time period is determined, and the calculation formula is: in, Indicates A radar speed gun is located in The optimal value of compression QP for a normal time period; represents a first preset parameter; represents the second preset parameter; represents an exponential function with a natural constant as base; Indicates The focus of attention during a normal period of time; Indicates A radar speed gun is located in The average value of the traffic condition complexity at all sampling times in a normal time period; Transmitting and communicating data collected by the radar speed gun during a normal time period according to the optimal value of the compressed QP of the radar speed gun during a normal time period; The data collected by the radar speed gun during the risk period, including the number of vehicles on the road, the speed of the vehicles and the distance between adjacent vehicles, are directly transmitted and stored.

10. The high-efficiency data communication method for a highway electromechanical system according to claim 9, characterized in that: The specific method of transmitting and communicating the data collected by the radar speed gun during the normal time period according to the optimal value of the compressed QP of the radar speed gun during the normal time period is as follows: The rounded value of the optimal compression QP value of the radar speed gun in the normal time period is used as the value of the parameter QP of the H.264 / AVC video coding standard, the number of vehicles in motion, the speed of the vehicles and the distance between adjacent vehicles collected by the radar speed gun in the normal time period are lossily compressed, the compressed data of the radar speed gun in the normal time period is obtained, and the compressed data of the radar speed gun in the normal time period is transmitted and stored.

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