CN101131796A

CN101131796A - Road traffic parameter checking device and method thereof

Info

Publication number: CN101131796A
Application number: CNA2007100148687A
Authority: CN
Inventors: 邢建平; 武华; 孟令国; 李伟业; 邱雪梅
Original assignee: Jinan Jossinfo Intelligence Science & Technology Co Ltd
Current assignee: Jinan Jossinfo Intelligence Science & Technology Co Ltd
Priority date: 2007-08-30
Filing date: 2007-08-30
Publication date: 2008-02-27
Anticipated expiration: 2027-08-30
Also published as: CN100498871C

Abstract

A kind of road traffic parameter determination device and determination method, it belongs to road traffic parameter collection field. A road traffic parameter determination device, includes vehicle real time monitor system which is composed of GPS vehicle monitor terminal GMT and monitor center MC, its characteristic is that: there is a GIS electron map linked with the vehicle real time monitor system, GIS electron map saves the real road information, sets electron enclosure in the wanted determine area in the GIS electron map. A road traffic parameter determination device, first judges whether the vehicle enter the first electron enclosure according to the gained data, if it has entered, the counter adds one, then determines the next data, to see whether there is new car entered, and then determines whether the car enters the second electron enclosure area, according to the data of the two electron enclosure area, calculates the road traffic parameter, gains the traffic state of the road. The date in this invention is real time, the range is large, and it is correct.

Description

Road traffic parameter detection device and detection method

Technical Field

The invention belongs to the field of road traffic parameter acquisition, and particularly relates to a device and a method for acquiring road traffic parameters by using a GPS (global positioning system) terminal.

Background

At present, the main methods capable of collecting traffic parameters include: induction coil based methods, methods using vehicle electronic tags, and more traditional methods based on video detection, infrared detection, and microwave detection, among others. However, most of these methods require a large amount of hardware facilities, and more importantly, the coverage area is limited to a certain extent, and real-time collection of traffic parameters cannot be realized.

With the development of the application of Global Positioning System (GPS) technology, more and more vehicles are equipped with GPS positioning systems. These vehicles then become probe vehicles that can collect road traffic parameters. The GPS is utilized to collect the road traffic parameters, and the method has the advantages of high precision, good real-time performance, all weather, no weather influence, simple installation and easy maintenance. Therefore, the GPS is widely used at present for collecting road traffic parameters.

However, the existing method for acquiring road traffic parameters by using the GPS comprises the following steps: firstly, GPS positioning information of all vehicles on the whole road is obtained, then information such as vehicle positions, speeds, time, directions and the like is extracted, and finally simple average calculation is carried out to obtain information such as average speeds of vehicles on the road, road traffic flow and the like. However, this method has the following disadvantages:

1. the impact of road traffic intersections cannot be excluded. When the vehicle runs to a traffic light intersection, the GPS information is collected to be invalid, and the data at the moment cannot reflect the traffic condition of the road and should be removed.

2. The influence of the entrance and exit cannot be excluded. When a GPS vehicle enters and exits a station or waits for passengers at the station, the acquired data cannot reflect the traffic condition of the road and should be removed.

3. The influence of the stop of the bus stop board and the stop of the taxi cannot be eliminated. When a bus enters or exits the stop board and a taxi is at a stop point, the collected data are invalid and should be removed.

The defects are inherent in the existing method for acquiring the road traffic parameters by using the GPS, and by adopting the methods, the accuracy of acquiring the road traffic parameters is reduced, and the actual traffic state of the road cannot be completely and accurately reflected.

Disclosure of Invention

The invention aims to provide a novel virtual coil road traffic parameter detection device and method based on positions, which can effectively avoid the defects of the existing method and improve the accuracy and the real-time performance of road traffic parameter acquisition.

The technical scheme of the invention is as follows: the road traffic parameter detection device comprises a vehicle real-time monitoring system consisting of a GPS vehicle monitoring terminal GMT and a monitoring center MC, and is characterized in that: and a GIS electronic map is also arranged and connected with the vehicle real-time monitoring system, actual road information is stored in the GIS electronic map, and an electronic fence is arranged in an area needing to be detected on the GIS electronic map.

A method for detecting road traffic parameters comprises the following steps:

firstly, judging whether a vehicle enters a first electronic fence area or not according to acquired data, if so, adding one to an electronic fence counter, then detecting next data to see whether a new vehicle enters or not, then detecting whether the vehicle enters a second electronic fence area or not, and calculating traffic parameters of a road according to data recorded in the two electronic fence areas to obtain the traffic condition of the road.

The invention has the beneficial effects that: the method is flexible, the electronic fence can be installed at will according to actual needs, and the method is not limited by space; data are collected in real time, and the range is wide and accurate; and automatic acquisition, automatic transmission, automatic processing and automatic display of data are realized.

Drawings

FIG. 1 is a general system block diagram of the present invention;

FIG. 2 is a schematic diagram of a virtual coil arrangement of the present invention;

FIG. 3 is a diagram of the virtual coil arrangement of the one-way road of the present invention;

FIG. 4 is a diagram of a two-lane road virtual coil arrangement of the present invention;

fig. 5 is a diagram of virtual coil network setup according to the present invention.

Detailed Description

As shown in fig. 1, the vehicle real-time monitoring system based on GPRS communication mode mainly comprises a GPS vehicle monitoring terminal (GMT) and a Monitoring Center (MC). The monitoring center receives data containing longitude, latitude, speed, direction and other information of the vehicle from the monitoring terminal, and displays the position and track of the vehicle on an electronic map after proper conversion and processing, thereby achieving the purpose of real-time monitoring.

The GPS virtual coil is set based on monitoring software of a monitoring center and is compared with received GPS detection vehicle information, and information such as road traffic volume, vehicle average speed and the like is obtained through analysis and calculation. The schematic diagram is shown in fig. 2. The specific implementation steps are as follows:

1. setting a virtual coil

And a computer connected with a database of the monitoring center is used as hardware for detecting the virtual coil. The GIS is an advanced system integrating information management and processing, can conveniently store road information, and can be well combined with other software. Therefore, the information of road length, longitude, latitude and the like can be stored in the GIS electronic map. On a GIS electronic map, two electronic fences C are arranged for a certain detection road _A 、C _B (see fig. 2). Then C _A 、C _B Corresponding to two detection areas A and B on the actual road, i call C _A 、C _B As a virtual coil, its range can be defined by the following two elliptical squaresAnd (5) describing the program. The virtual coil can effectively avoid the influence of road traffic intersections and stops of taxies and buses, and the virtual coil setting method of one-way roads, two-way roads and road networks is shown in figures 3, 4 and 5.

Wherein l _A 、l _B 、λ _A 、λ _B The longitude and latitude of the virtual coil center are respectively, and the long and short axes of a and b are respectively. The round or square shape can be set according to the actual situation.

2. Parsing GPRS information

Since the message transmitted by the GPRS method includes the longitude, latitude, speed, direction of the vehicle and its own ID number. Accordingly, data required for the virtual coils can be obtained by the corresponding processing, and the data are arranged as the array a.

a＝(1，λ，v，θ，t，m)(3)

Wherein t is time, 1, lambda, v and theta are longitude, latitude, speed and direction angle of the vehicle at the time t respectively, and m is the ID number of the vehicle.

3. Virtual coil detection

When the vehicle M travels from left to right on the road on the lane shown in FIG. 2, the different time arrays a are different, the real-time 1 and lambda values of the equation (3) are substituted into the equation (1) to check whether the test is true, and if the test is true, the vehicle M enters the virtual coil C _A At this time, the values of θ, v, t, m in the array a are recorded, and the virtual coil C _A Adding 1 to the counter, sequentially judging whether the formula (1) is established when the array at the next moment is received, judging whether the moment M is equal to the last moment M, and if so, indicating that the vehicle M does not leave the virtual coil C at the moment _A If not, the counter is added with 1 to record the theta, v, t and m in the array a.It can also be detected whether the vehicle M enters the virtual coil C _B . Write down the data of theta, v, t, m, thus virtualizing the coil C _A And C _B Repeatedly detecting passing vehicles, recording data theta, v, t and m so as to calculate traffic parameters, and performing software programming in the virtual coil detection computer through the algorithm description.

4. Calculating road traffic parameters

4.1 road average speed detection

There are two methods of calculating the average velocity: time-averaged velocity and distance-averaged velocity. The time-averaged speed refers to the average of the speeds of all vehicles passing through a given road segment node in a given time period. The distance average is the average speed of all vehicles traveling on a specified road segment over a period of time.

(1) Time-averaged velocity measurement

When the virtual coil C _A When the count is n, the speed of each vehicle is v _i (i =1,2,3,. N) then the total average speed of all vehicles is:

(2) Distance average velocity measurement

According to the array a recorded by the two virtual coils and the longitude and latitude of the two coils, the method is convenientThe average vehicle speed in the section being measured at that time is known. Let the total length of the measured section be s and the travel time of the ith vehicle be T _i (i =1, 2.. N), and the time t at which the vehicle passes through the first end intersection is t ₁ The time when the road passes another end crossing is t ₂ Then the distance average speed of the vehicle is:

wherein, T _i ＝t ₂ -t ₁ To obtain

Then, the traffic flow Q can be obtained.

4.2 traffic flow detection

The traffic flow is also called traffic volume, which means the number of vehicles passing through a certain point, a certain section or a certain road in a unit time, and in the continuous traffic flow, the following relationship exists:

Q＝VK (6)

wherein Q is traffic flow, V is distance average speed, and K is traffic flow density.

Claims

1. The utility model provides a road traffic parameter detection device, includes the vehicle real time monitoring system who comprises GPS vehicle monitor terminal GMT and surveillance center MC, its characterized in that: and a GIS electronic map is also arranged and connected with the vehicle real-time monitoring system, actual road information is stored in the GIS electronic map, and an electronic fence is arranged in an area needing to be detected on the GIS electronic map.

2. A method for detecting road traffic parameters is characterized in that: comprises the following steps:

firstly, judging whether a vehicle enters a first electronic fence area or not according to the acquired data, if so, adding one to an electronic fence counter, then detecting next data to see whether a new vehicle enters or not, then detecting whether the vehicle enters a second electronic fence area or not, and calculating the traffic parameters of the road according to the data recorded in the two electronic fence areas to obtain the traffic condition of the road.