WO2011028092A1

WO2011028092A1 - Traffic monitoring and enforcement system and a method thereof

Info

Publication number: WO2011028092A1
Application number: PCT/MY2010/000150
Authority: WO
Inventors: Mohamed Rehan Karim; Ahmad Saifizul Abdullah
Original assignee: University Malaya (U.M.)
Priority date: 2009-09-07
Filing date: 2010-08-20
Publication date: 2011-03-10
Also published as: MY169914A

Abstract

An integrated traffic monitoring and enforcement system is defined in this present invention as a system that is comprised of a set of sensors for providing signals in response to vehicle travel across the sensors, a signal conditioning component and a data acquisition component to digitize the signal, and a processor unit and a software for processing and computing the digitized signals to determine various traffic and vehicle parameters. This invention is a system and a method for an integrated quartz sensor based traffic data-collection and monitoring, and variable speed limit enforcement and weigh-in-motion based weight enforcement. The proposed invention is developed using a quartz sensor as a primary sensor for acquiring traffic and vehicle parameters.

Description

TRAFFIC MONITORING AND ENFORCEMENT SYSTEM AND A METHOD THEREOF

FIELD OF INVENTION The present invention relates generally to an integrated traffic data collection and monitoring, and an enforcement system, more particularly to an integrated quartz sensor based traffic data-collection and monitoring system, variable speed limit enforcement system and a weigh-in-motion based weight enforcement system. BACKGROUND OF INVENTION

The state of the art in transportation engineering has advanced dramatically over the last decade, and the application of new and more flexible transportation instrumentations and control devices, software systems, computer hardware, communications and surveillance technologies, and analysis methods has become commonplace. One of the major fields in transportation engineering in contributing to the country economic growth is traffic engineering. Many metropolitan areas have created traffic management centers (TMC) with closed-circuit television (CCTV) cameras, traffic and weather sensors, electronic variable message signs (VMS), traffic signals, and ramp meters to monitor and manage traffic flow on streets and freeways. And as information is received at the TMC, travelers are informed of problems via radio, television, the Internet, and VMS along the roadways.

Generally traffic engineering involves traffic data collection for statistics, traffic monitoring, traffic enforcement such as speed and weight limit enforcement and traffic management. Currently many kinds of systems or devices are available which measure or monitor or enforce traffic dedicatedly. The use of these dedicated or nonintegrated systems or devices in traffic data-collection or monitoring and traffic enforcement create a lot of problems in terms of data consistency and management among road and enforcement agencies. In addition, due to the limited measurement capability of each system or device such as incomprehensive measurable traffic parameters has resulted in the total cost for traffic data collection and monitoring cost ineffective, inefficient speed and weight enforcement, and extremely difficult to implement the actual regulation related to speed limit enforcement.

At present, the known system use various types of sensors. The sensor technologies used for the system can be divided into three major categories: intrusive sensors (in- roadway), non-intrusive sensors (above roadway or roadside), and off-roadway sensors. Each sensor offers strengths and limitations; the successful application of the sensors depends on proper device selection to meet specific system requirements.

The major limitations of non-intrusive and off-roadway sensors, such as camera, infrared, microwave radar, ultrasonic, probe vehicles, and remote sensing, are as follows:

• Most of them are only capable of measuring dedicated traffic parameter;

• Using them to measure vehicle parameters, such as gross vehicle weight (GVW), axle weight and wheelbase, is impossible; and

• These sensors are not robust to precipitation and climate changes.

The measurement from intrusive sensor is generally more robust and used in continual and permanent measurement procedure of obtaining traffic data. The most prominent intrusive sensor is weigh-in-motion (WIM) sensors and its main advantage as compared to other intrusive sensors is their ability to measure vehicle weight. Four major types of WIM sensors are available on the market, and they are basically based on two different sensor technologies, i.e., strain gauge and piezoelectric. Bending plate and load cell WIM sensors use strain gauge technology and are dedicated to measuring vehicle weight. If this type of sensor is used to measure other traffic parameters, such as speed and axle spacing, the number of sensor arrays must be increased, or it must be integrated with other hardware. This will make the installation work tedious and will definitely increase the cost. Other types of WIM sensors use piezoelectric technology, and the quartz sensor has been introduced to overcome the limitations of ordinary piezoelectric WIM sensors. At present, WIM system is only used for an enforcement aid of overloaded heavy-duty vehicle and collecting related traffic data of commercial motor vehicle.

The existing system or device for measuring dedicated traffic parameter can be integrated to provide an all-in-one integrated system for traffic data collection, monitoring and enforcement purposes. However, this method will definitely not be cost effective and time consuming. Thus, the need to provide an all-in-one integrated and accurate traffic data collection, monitoring and enforcement system at a reasonable cost is undeniable. This type of system must be capable of simultaneously measuring ail essential traffic and vehicle parameters in real-time. It also uses the minimum number of sensors necessary to provide the maximum number of various traffic parameters. Finally, the measurement from the system must also be accurate and reliable for enforcement purposes.

SUMMARY OF INVENTION

Accordingly there is provided an integrated traffic monitoring and enforcement system which integrates a quartz sensor based traffic data-collection and monitoring system, variable speed limit enforcement system and weigh-in-motion based weight enforcement system characterized in that the system includes a sensor array, a height detector, an image capturing device, a multi-parameter weather transmitter and a roadside central processing unit wherein the sensor array further includes a vehicle presence detector and quartz sensor embedded in roadway surface, the height detector having means of detecting vehicle height, the image capturing device having means of capturing images when a vehicle is passing through the sensor array, the multi-parameter weather transmitter having means of measuring air quality and weather data, the roadside central processing unit further includes an industrial microprocessor with signal conditioning and data acquisition board, charged amplifier, a loop detector, an integrated circuit board, a power supply, an Uninterruptable Power Supply (UPS) back-up power supply and plurality of modems.

Furthermore, there is provided a method of processing data from an integrated traffic monitoring and enforcement system which includes a sequence of operations of data processing for traffic data collection and monitoring, a subsequent operations of data processing for variable speed enforcement and a subsequent operations of data processing for weigh-in-motion (WIM) based weight enforcement characterized in that the traffic data collection and monitoring operation includes the steps of analyzing a vehicle detection signal from a vehicle presence detector using a microprocessor, confirming whether or not the vehicle has been detected passing over the sensor array, the vehicle are fully within the sensor array zone and is not straddling a lane, recording an error if the vehicle is not detected, processing a plurality of signals from the set of sensors to determine traffic and ancillary data, transferring data from and snap image with overlay data to subsequent analysis for the variable speed enforcement operation and the WIM based weight enforcement operation, the variable speed enforcement operation includes the steps of, determining by using a processor whether or not the vehicle weight is greater than a user-defined weight limit, determining by using the processor whether or not the vehicle speed is greater than a specified speed limit, recording violated data and snap image, transferring the data and snap image to law enforcement agencies or other agencies, the WIM based weight enforcement operation includes the steps of identifying vehicle laden weight (BDM) based on vehicle classification, determining whether or not vehicle gross vehicle weight (GVW) and axle weight are greater than BDM and user- defined axle weight limit, respectively, processing the violated vehicle data by overlaying the data to the snap image and recording violated data and snap image under the category of weight violation, transferring the data and snap image from to law enforcement agencies or other agencies.

The present invention consists of several novel features and a combination of parts hereinafter fully described and illustrated in the accompanying description and drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, wherein:

FIGURE 1 : is a diagram showing a top view example of a section of an integrated traffic monitoring and enforcement system according to an embodiment of the present invention in place on a two-lane road/highway;

FIGURE 2: shows a front view example of a section of an integrated traffic monitoring and enforcement system according to an embodiment of the present invention in place on a two-lane road/ highway; FIGURE 3: shows a schematic diagram of control unit component configuration suitable for use in an integrated traffic monitoring and enforcement system according to an embodiment of the present invention;

FIGURE 4: shows a flowchart depicting overall subsequent data processing of an integrated traffic monitoring and enforcement system according to an embodiment of the present invention;

FIGURE 5: shows a flowchart depicting subsequent data processing of variable speed limit enforcement;

FIGURE 6: shows a flowchart depicting subsequent data processing of WIM based weight enforcement; FIGURE 7: shows a flowchart depicting subsequent data processing of a quartz sensor signal according to an embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to an integrated traffic monitoring and enforcement system and a method thereof. Hereinafter, this specification will describe the present invention according to the preferred embodiments of the present invention. However, it is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the scope of the appended claims.

The following detailed description of the preferred embodiments will now be described in accordance with the attached drawings, either individually or in combination.

An integrated traffic monitoring and enforcement system is defined in this present invention as a system that is comprised of a set of sensors for providing signals in response to vehicle travel across the sensors, a signal conditioning component and a data acquisition component to digitize the signal, and a processor unit and a software for processing and computing the digitized signals to determine various traffic and vehicle parameters for traffic data collection, monitoring and enforcement purposes. This invention is a system and a method for an integrated quartz sensor based traffic data-collection and monitoring, and variable speed limit enforcement and weigh-in-motion based weight enforcement. The proposed invention is developed using a quartz sensor as a primary sensor for acquiring traffic and vehicle parameters. The main advantage for choosing a quartz sensor is its ability to measure various traffic and vehicle parameters without any additional hardware, ease of installation and robust to precipitation and weather changes.

When a force is applied to the quartz sensor surface, the quartz disks yield an electric charge that is proportional to the applied force through a piezoelectric effect. Then, the electric charge is converted by a charge amplifier into a proportional voltage, which then must be further processed as required. The sensor must be integrated into the road surface and is, thus, only viable for permanent installation applications. As a vehicle starts to drive over the sensor, the software begins gathering signal. Signal is gathered until the vehicle's entire axle has passed completely over the sensor. As the method for processing the signal has been improved (trade secret - involve a lot of techniques) the system is capable of measuring various traffic and vehicle parameters for various vehicle types including lighter-weight vehicle such as subcompact car. This significant invention provides more and better data for traffic data-collection and monitoring, which eventually can be used for many purposes such as traffic data management (statistics), overload detection, bridge protection, weight dependent tolling, road safety research, pavement management system and future road planning. A further reason why traffic information is required is for enforcement of regulations and laws. Simple information regarding vehicle speed and weight will be used to enforce speed and weight limits. The present invention can overcome problems related to inefficient implementation of speed and weight limit enforcement. Present regulation stated that different speed limit should be enforced for light-weight and heavy-weight vehicle traveling on highway. However, due to limitations of measurement capability of existing speed limit enforcement devices it is impossible to implement the regulation. Using this present invention, it is possible to implement variable speed limit enforcement based on vehicle weight and vehicle type.

There are also regulations relating to maximum allowable weights for heavy-weight vehicle which are borne out of concerns for safety and also to lessen the damage that over laden vehicles may do to the road structure. However, the limitations of enforcement based on existing static weighing scale such as long-queue, time consuming and limited operation is root cause of inefficient implementation of weight limit enforcement. This present invention can weigh vehicles while they are in motion and for this reason will overcome limitations of static weigh scale and improve implementation of weight limit enforcement. This present invention may also incorporate other sensors or sensing devices such as camera, height detector and multi-parameter weather transmitter to optimize the measurement capability and enhance enforcement purposes.

Figure 1 and Figure 2 show top-view and front-view of an example a section of a traffic monitoring system in place on a two-lane roadway system. The system comprises sensor array embedded in roadway surface, height detector, camera set, multi-parameter weather transmitter and central processing unit. The sensor array consists of vehicle presence detector (e.g. inductive loop) and quartz sensor for providing traffic and vehicle parameters. Image from camera will be snapped when vehicle passing through the sensor arrays (i.e. vehicle presence detectors and quartz sensors). The central processing unit will then process all signals from sensing devices. The produced data will be recorded and transmitted to central station. The schematic diagram of roadside central processing unit with example of its configuration is shown in Figure 3. The proposed unit comprises an industrial microprocessor complete with data acquisition and signal conditioning board, charge amplifier, loop detector, ROAD-i™ integrated circuit board, power supply and UPS back- up power supply. The roadside central processing unit is equipped with modems, enabling remote retrieval of traffic data.

The overall sequence of operations as a vehicle is processed by the system is depicted in the flowcharts as shown in Figure 4. For convenience of description, it will be assumed that the vehicle is in one of the lanes. It will be appreciated by a person skilled in the art, however that the same process would apply to a vehicle in the other lane. Referring first to Figure 4, which depicts operation of the primary roadside central processing unit, when a vehicle passes over sensor array, the microprocessor first analyze a vehicle detection signal [4a] from vehicle presence detector, and confirms in decision step [4b] whether or not the vehicle has been detected accurately. If it has not, then it records an error [4c]. If the vehicle has been detected accurately, the processor processes all of the signals [4d] from the set of sensor to determine traffic and ancillary data [4e] as an example given in Table 1. Related data from [4e] and snap image with overlay data [4f] will be further used in subsequent analysis for variable speed enforcement and WIM based weight enforcement as given in flowcharts of Figure 5 and 6, respectively.

1. Date of Vehicle Passing

2. Time of Vehicle Passing

3. Record Number

4. Traffic Direction

5. Lane Number

6. Vehicle Classification

7. Spot Speed

8. Acceleration

9. Time Headway

10. Space Gap

11. Center-to-Center Spacing Between Axles

12. Wheelbase (front-most to rear-most axle)

13. Vehicle Height

14. Wheel Weight

15. Axle Weight

16. Axle-Group Weight

17. Gross Vehicle Weight

18. ESAL (Equivalent Single Axle Load)

19. Wind Speed

20. Wind Direction

21. Rainfall

22. Rain Intensity

23. Barometric Pressure

24. Ambient Air Temperature

25. Air Humidity

Table 1 For sequence of data analysis operation of variable speed limit enforcement as shown by flowchart in Figure 5, the processor determines whether or not vehicle weight is greater than a user-defined weight limit [5a]. If the vehicle weight is greater than the user-defined weight limit, the speed limit is equal to HW (i.e Heavy-weight) speed limit [5b]. If it has not, the speed limit is equal to LW (i.e Light-weight) speed limit [5c]. Furthermore, the processor determines whether or not vehicle speed is greater than a specified speed limit

[5d]. If it is greater, than the vehicle is classified and recorded under the category of speed violation and all related processed data are overlaid to the snap image [5e]. The violated data and snap image will be recorded separately and transfer to police central computer or any other related agencies [5f]. If it has not, the processor takes no further action [5g].

For sequence of data analysis operation of WIM based weight enforcement as shown by flowchart in Figure 6, the processor first identifies vehicle laden weight (BDM) based on vehicle classification [6a]. Then, the processor determines whether or not vehicle gross vehicle weight (GVW) and axle weight are greater than BDM and user-defined axle weight limit, respectively [6b] & [6c]. If it is greater, than the vehicle is classified and recorded under the category of weight violation and all related processed data are overlaid to the snap image [6d]. The violated data and snap image will be recorded separately and transfer to road transport department central computer or any other related agencies [6e]. If it has not (i.e. no violation), the processor takes no further action [6f].

The details sequence of operations of data processing from quartz sensor is depicted in the flowchart shown in Figure 7.

Claims

1. An integrated traffic monitoring and enforcement system which integrates a quartz sensor based traffic data-collection and monitoring system, variable speed limit enforcement system and weigh-in-motion based weight enforcement system characterized in that the system includes a sensor array, a height detector, an image capturing device, a multi-parameter weather transmitter and a roadside central processing unit wherein the sensor array further includes a vehicle presence detector and quartz sensor embedded in roadway surface; the height detector having means of detecting vehicle height; the image capturing device having means of capturing images when a vehicle is passing through the sensor array; the multi-parameter weather transmitter having means of measuring air quality and weather data; the roadside central processing unit further includes an industrial microprocessor with signal conditioning and data acquisition board, charged amplifier, a loop detector, an integrated circuit board, a power supply, an Uninterruptable Power Supply (UPS) back-up power supply and plurality of modems.

2. The system as claimed in claim 1 , wherein the quartz sensor as primary sensor for acquiring traffic and vehicle parameters.

3. The system as claimed in claim 1 , wherein the integrated circuit board is a ROAD- i™ circuit board.

4. A method of processing data from an integrated traffic monitoring and enforcement system which includes a sequence of operations of data processing for traffic data collection and monitoring, a subsequent operations of data processing for variable speed enforcement and a subsequent operations of data processing for weigh-in-motion (WI ) based weight enforcement characterized in that the traffic data collection and monitoring operation includes the steps of:

a. analyzing a vehicle detection signal [4a] from a vehicle presence detector using a microprocessor;

b. confirming whether or not the vehicle has been detected [4b] passing over the sensor array, the vehicle are fully within the sensor array zone and is not straddling a lane;

c. recording an error [4c] if the vehicle is not detected in step 'b';

d. processing a plurality of signals [4d] from the set of sensors to determine traffic and ancillary data [4e];

e. transferring data from step 'd' above [4e] and snap image with overlay data

[4f] to subsequent analysis for the variable speed enforcement operation and the WIM based weight enforcement operation; the variable speed enforcement operation includes the steps of:

a. determining by using a processor whether or not the vehicle weight is greater than a user-defined weight limit [5a];

b. determining by using the processor whether or not the vehicle speed is greater than a specified speed limit [5d];

c. recording violated data and snap image;

d. transferring the data and snap image from step 'c' to law enforcement agencies or other agencies; the WIM based weight enforcement operation includes the steps of

a. identifying vehicle laden weight (BDM) based on vehicle classification [6a]; b. determining whether or not vehicle gross vehicle weight (GVW) and axle weight are greater than BDM and user-defined axle weight limit, respectively [6b] & [6c];

c. processing the violated vehicle data by overlaying the data to the snap image and recording violated data and snap image under the category of weight violation [6d];

d. transferring the data and snap image from step 'c' to law enforcement agencies or other agencies [6e].