CN106023590B - A method and system for quickly detecting congestion in an inner area of an urban road intersection - Google Patents

Abstract

The present invention is a rapid detection method and alarm system for congestion in the internal area of an urban intersection. The invention uses a microwave detector to detect vehicle congestion in the internal area of an urban road intersection, and the congestion information is transmitted to a video detector installed at the intersection through a wireless/wireless network, thereby triggering the video detector to identify congestion. The built-in algorithm of the video detector is used to calculate the congestion warning index. If the index reaches the threshold, the network is used to send the warning index information and video stream information to the traffic management department for decision-making and guidance processing. The above method can be used to quickly identify internal congestion at intersections, effectively improve the control efficiency of urban road intersections, prevent overflows, deadlocks and other phenomena, and achieve the purpose of alleviating traffic congestion.

Description

A method and system for quickly detecting congestion in an inner area of an urban road intersection

technical field

The invention belongs to the technical field of intelligent transportation, and in particular relates to a rapid congestion detection technology, which is a method and a system for rapid detection of congestion in an internal area of an urban road intersection.

Background technique

With the continuous increase of car ownership, urban road congestion is becoming more and more serious. As an important part of urban traffic transfer and safety, road intersections are gradually becoming the origin and hardest hit areas of traffic congestion. Due to urban planning issues, signal control design issues, and drivers' driving behavior, urban road intersections often experience congestion or even deadlocks, which seriously affect the smooth operation of urban road network traffic. Therefore, rapid detection of internal congestion at intersections and timely early warning processing are of great significance for alleviating urban road traffic congestion and ensuring driving safety.

Contents of the invention

Aiming at the problem of insufficient early warning and detection of congestion in the internal area of the current urban road intersection, the present invention realizes rapid and accurate detection of congestion by adopting a method of combining microwave detection and video detection, and at the same time realizes rapid detection of congestion at road intersections by combining early warning means. deal with. Specifically adopt the following technical solutions: a method for early warning and detection of congestion in the inner area of an urban intersection, comprising the following steps:

(1) Microwave detectors are installed at urban intersections, and the microwave detectors collect the average vehicle speed v _i and the actual movement direction f _i of vehicles passing through the inner area of the intersection during the green light;

(2) Set the vehicle speed early warning interval v _d = [0, v _min ] for the congestion situation;

(3) Identify the vehicles at the intersection with different signal phases, and judge whether the vehicles belonging to the phases are clear within the green light time;

Set the direction f ₀ of the reference motion of the traffic flow, and take the direction of the centerline of the line connecting the fan edges in the detection range of the microwave detector as the standard direction, so that α represents the angle at which the actual movement direction of the traffic flow deviates from the standard direction. When the microwave detector continuously shows two traffic flows with α≥60°, it is determined that the vehicle within the green light time of the previous phase is clear;

(4) video detectors are installed at intersections to visually identify the state of the inner area of the intersection;

When the vehicle speed v _i ∈ v _d and α≥60°, the video detector is triggered, and the video detector detects the vehicle occupancy space w, the number of vehicles n and the average vehicle speed v _n , where the intersection is delineated in the detection area of the video detector The interior area W, the proportion of the space occupied by vehicles at the intersection in Indicates the average occupied space of the vehicle;

(5) Calculating the internal congestion warning index of the intersection:

Among them, P is the congestion warning index inside the intersection, t is the congestion continuous detection time; the congestion warning threshold is set to K, when P≧K, the congestion alarm is triggered, and the internal congestion index of the intersection and the video stream of the video detector are sent to the command center of the traffic control department at the same time.

Preferably, it includes a microwave traffic information detection and processing module, a video image processing module, and a wireless communication module, wherein the microwave traffic information detection and processing module is used for vehicle speed collection, traffic flow direction collection, vehicle motion state collection, etc.; video image The collection and processing module is used for vehicle image collection, vehicle speed collection, vehicle occupied space collection, intersection internal area collection, and traffic flow collection; the congestion warning calculation module is used to calculate the congestion warning index; the wired/wireless communication module is compatible with TCP/ IP, Wifi, 3G/4G and other wired/wireless transmission technologies.

Preferably, the microwave traffic information detection and processing module collects vehicle speed information, vehicle flow movement direction information and vehicle movement state information in the inner area of the intersection through microwave detection technology, and detects the vehicle speed v _i inside the intersection during the green light period , judging whether it is within the traffic speed warning interval v _d = [0, v _min ], and judging whether the angle α deviating from the standard direction is greater than 60° by detecting the direction of traffic flow movement. When v _i ∈ v _d and α ≥60°, the video image processing module and the congestion warning calculation module are triggered wirelessly.

Preferably, the video image processing module is triggered by the congestion information, automatically adjusts the position through the pan/tilt, detects the interior of the intersection, and recognizes the vehicle image, vehicle speed, vehicle occupied space, internal area space of the intersection and traffic flow.

Preferably, the congestion warning calculation module first calculates Secondly, set the congestion detection time t; finally, calculate the congestion warning index P through the vehicle speed, vehicle occupied space, internal area space of the intersection and traffic flow detected by the video image processing module, and set the congestion warning threshold, when P When it is greater than or equal to the congestion warning threshold, a congestion alarm is triggered, and the result is transmitted to the traffic management center through the network.

Preferably, the microwave traffic information detection and processing module and the video image processing module are installed on the outrigger or other crossing poles; the congestion warning calculation module is placed in the roadside signal control box.

The present invention has following beneficial technical effect:

(1) Advanced functions, convenient and practical, can quickly realize congestion detection in the inner area of urban road intersections;

(2) The double detection calculation of microwave detection and video detection is used to make the detection accuracy higher;

(3) The early warning means can realize rapid disposal of congestion, prevent deadlock and improve safety.

Description of drawings

Figure 1 is a schematic diagram of the detection and early warning device.

Fig. 2 is a flow chart of early warning and detection of congestion in the internal area of urban road intersections.

Fig. 3 is a schematic diagram of determining the standard direction of a microwave detector.

Detailed ways

1——Microwave detector (installed on the pole);

2——Video detector (installed on the pole);

3——Congestion warning calculation module (installed in the drive test signal control box)

4——Wireless communication module (installed in the drive test signal control box)

5——Microwave detector detection range clamping line

6——The midline of the line connecting the fan sides of the detection range of the microwave detector

7—Standard direction of deviation angle

In Figure 1, the microwave traffic information detection and processing module collects the vehicle speed information, traffic flow direction information and vehicle movement state information in the internal area of the intersection through microwave detection technology, and starts the video image processing module by judging the vehicle speed and deviation angle; The video image processing module is triggered by the congestion information, automatically adjusts the position through the PTZ, detects the interior of the intersection, and recognizes the vehicle image, vehicle speed, vehicle occupied space, internal area space of the intersection and traffic flow. Then, send the data to the congestion warning calculation module through wireless (Wifi, 3G/4G, etc.); the congestion warning calculation module first uses the vehicle speed obtained by the microwave traffic information detection and processing module and the video image processing module to calculate the warning geometric mean vehicle speed; Secondly, set the congestion detection time t and consider t ≥ 100s; finally, calculate the congestion warning index P through the vehicle speed, vehicle occupied space, internal area space of the intersection and traffic flow detected by the video image processing module, and set the congestion The early warning threshold is K, and when P≧K (K generally takes 3), a congestion alarm is triggered, and the result is transmitted to the traffic management center through the network.

In Figure 2, the congestion warning detection method in the inner area of an urban intersection first collects vehicle speed and traffic flow direction through the microwave detector installed at the intersection; secondly, judges the vehicle speed and deviation angle, and triggers the video if it reaches the preset value The detector collects the space occupied by vehicles, the number of vehicles and the average speed of vehicles, calculates the average speed required for the congestion warning index, and calculates the congestion warning index; finally, judges whether the preset value of the congestion warning index is reached, and if it reaches the preset value, the warning information is sent to Traffic management command center.

In FIG. 3 , the standard direction of the deviation angle is set by the center line connecting the line between the detection range of the microwave detector and the fan edge of the detection range of the microwave detector.

Claims (6)

1. a kind of urban intersection interior zone congestion warning detection method, which is characterized in that include the following steps：

(1) microwave detector is installed in urban intersection, vehicle passes through in intersection during the microwave detector acquisition green light The average speed v in portion region_iWith wagon flow actual motion direction f_i；

(2) the vehicle speed prewarning section v of congestion is set_d=[0, v_min]；

(3) identification unlike signal phase enters the vehicle of intersection, judges whether affiliated phase vehicle empties in green time；

The direction f of wagon flow baseline locomotor is set₀, using the center line direction of the covering of the fan side line of microwave detector detection range as standard Direction, orderα represents that wagon flow actual motion direction deviates the angle of reference direction, when continuously occurring two in microwave detector During α >=60 ° of stock wagon flow, then the vehicle in upper phase green time is judged to empty；

(4) video detector is installed in intersection, to visualize the state of identification intersection interior zone；

As speed v_i∈v_dAnd during α >=60 °, video detector, video detector detection vehicle occupied space w, vehicle number are triggered Measure n and vehicle average speed v_n, wherein delimiting intersection interior zone W in video detector detection zone, intersection is by vehicle The ratio of occupied spaceWhereinRepresent the average occupied space of vehicle；

(5) congestion warning index inside intersection is calculated：

<mrow> <mi>P</mi> <mo>=</mo> <mfrac> <mn>1</mn> <mn>10</mn> </mfrac> <mo>&amp;CenterDot;</mo> <mi>t</mi> <mo>&amp;CenterDot;</mo> <mi>p</mi> <mo>&amp;CenterDot;</mo> <mfrac> <mn>1</mn> <mover> <mi>v</mi> <mo>&amp;OverBar;</mo> </mover> </mfrac> <mo>,</mo> </mrow>

Wherein, P is congestion warning index inside intersection,T continues detection time for congestion；Congestion warning threshold value It is set as K, as P≤K, triggers jam alarming, the video flowing of the inside congestion index of the intersection and video detector is same When be sent to the command centre of traffic control department.

2. a kind of alarm system for applying urban intersection interior zone congestion warning detection method as described in claim 1, It is characterized in that:Including microwave traffic information detection and processing module, Computer Vision module, wire/wireless communication module, wherein Microwave traffic information detects and processing module is for car speed acquisition, the acquisition of the wagon flow direction of motion, state of motion of vehicle acquisition； Digital video image acquisition and processing module is in vehicle image acquisition, car speed acquisition, the acquisition of vehicle occupied space, intersection The acquisition of portion region, traffic flow acquisition；Congestion warning computing module is used to calculate congestion warning index；Wire/wireless communication module energy Compatible TCP/IP simultaneously, the wire/wireless transmission technology of Wifi, 3G/4G.

3. alarm system according to claim 2, it is characterised in that：Microwave traffic information detection and processing module pass through micro- Ripple detection technique to the vehicle speed information of intersection interior zone, wagon flow direction of motion information and state of motion of vehicle information into Row acquisition, by detecting the Vehicle Speed v inside intersection during green light_i, judge it whether in congestion speed Early warning section v_d=[0, v_min] in, while judge whether it deviates the angle [alpha] of reference direction big by detecting the wagon flow direction of motion In 60 °, when detecting v_i∈v_dAnd α >=60 °, wirelessly trigger Computer Vision module and congestion warning calculates Module.

4. alarm system according to claim 3, it is characterised in that：Computer Vision module is connected to congestion information and touches Hair, by holder automatic adjusting position, is detected intersection inside, and identification vehicle image, car speed, vehicle occupy empty Between, intersection interior zone space and vehicle flowrate.

5. alarm system according to claim 4, it is characterised in that：Congestion warning computing module calculates firstSecondly, congestion is set to continue detection time t；Finally, the vehicle speed detected by Computer Vision module Degree, vehicle occupied space, intersection interior zone space and information of vehicle flowrate calculate congestion warning indices P, and set congestion pre- Alert threshold value when P is more than or equal to congestion warning threshold value, triggers jam alarming, result is transferred in traffic administration by network The heart.

6. alarm system according to claim 5, it is characterised in that：Microwave traffic information detects and processing module, video Image processing module is mounted on semi-girder bar or other intersection bars have；Congestion warning computing module, which is put in, is placed in trackside letter In number control cabinet.