CAPUS LAURENCE (CA)
| WO2015042776A1 | 2015-04-02 |
| US9154982B2 | 2015-10-06 | |||
| US20160019788A1 | 2016-01-21 |
See also references of EP 3465657A4
| Title : Control and manage Traffic Light System with VANET Claim #1: Programming of traffic lights (static, semi-actuated or fully actuated) with data from VANET according to the current method of ITE (fig 1, 2, 3) Our claim is to use the VANET network to collect data and do the programming of traffic lights (static, semi-actuated or fully-actuated). These data would be used to replace historical data measured in the field. The process is the same process as ITE recommend (fig 1). This method has never been proposed, it will permit to get the data at any time, to make simulation scenarios as needed. It shall avoid manual counts vehicles or to install expensive devices sensors in the field. Claim #2: Loop detectors replacement using VANET This claim is to use the VANET network according to the architecture shown in figure 4 to replace the semi-actuated or fully actuated existing systems. The system we propose will make use of loop detectors obsolete. We propose to use our system rather than install new loop detectors at intersections. The same task as a loop detector can be do by our system. Claim #3: To control traffic lights signal in real time using VANET This claim is to use the VANET network as shown in Figure 5 to control the TLS in real-time. The method is explained in the attached article (Improving Traffic Lights Management Information Sytems Using Available by VANET Vaudrin and Capus). It consists of real time processing data collected by our system and transmit the signal to the traffic lights with a dedicated Internet network. This system does not currently exist. We propose an algorithm in the article based on the average occupancy rate of each road segment but one can use different algorithms. The essential ingredient is to provide information in real time at a frequency of 0.1 seconds and to use an efficient algorithm to process data provided by the system. Claim # 4: Using data from VANET to do traffic and urban studies It is possible to know the flow of traffic in a given period and vehicle movements in using parameters provides by VANET. Our claim is to use the VANET network according to the figure 6 to collect data and to use them to make traffic studies. Data will replace the historical data measured in the field through surveys or studies origin-destination. This innovation will save significant amounts to public administrations for the collection of such data. Claim #5: Management of major events with the help of VANET This claim is to use VANET network as shown in Figure 7 to help to manage circulation during maj or events (sporting, cultural, parades, manifestation, etc.). This additional information will help human controler and traffic officer to manage circulation during these events. Officials from the control center will then use this information to decide the best strategy. This is additional information that will be complementary to other systems (cameras). The essential ingredient of this claim is to provide realtime information on the circulation movements which is not possible with current systems. |
| AMENDED CLAIMS received by the International Bureau on 25 September 2017 (25.09.2017) In the Claims: The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1. A method for programmi ng traffic lights with data from vehicular ad hoc network VANET, said method comprises the foliowing steps: a. construct an algorithm based on the average occupancy rate of each road segment, b. transfer said data from VANET to a computer control center operating said algorithm, c. process said data with said algorithm, d. construct a dedicated internet network between said computer control center and said traffic lights, e. send the signal provided by said algorithm through said dedicated internet network to program said traffic lights, thus permit to get data at any time for managing circulation traffic in real-time and to make simulation scenarios as needed. 2. (canceled) 3. The method of claim 1 wherein said data from VANET are transferred to said computer control center at a frequency of 0,1 seconds in real time. 4. (canceled) 5. The method of claim 1 is used to manage traffic lights during major events. 6. The method of claim 5 wherein said major events are sporting, cultural, parades, manifestation. 7. The method of claim 1 or 5 wherein said traffic lights are static 8. The method of claim 1 or 5 wherein said traffic lights are semi-actuated. 8. The method of claim 1 or 2 wherein said data are transferred by means of a radiocommunication tower, 9. The method of claim 1,2 or 8 wherein said data are relatives to speed, acceleration, distance between vehicles, brake system. 10. The method of clai m 1 wherein said algorithm is based on the average occupancy rate of each road segment. 11. The method of claim 1 wherein said commu nication system is a dedicated internet n etwork. 12. The method of claim 1 wherein said communication system is a wireless communication. 13. The method of claim 1 wherein said data from VAN ET are transferred to said computer cont rol center in real time at frequencies approved accordance with norm IEEE.S12.l lp. 14. The method of claim 1 is used to ma ke u rban stu dies and to plan transportation studies. 15. The method of claim 3 wherein a decision-making center is establ ished in order to give comprehensible and essential information to traffic officers who control the traffic during said events. |
1-Description of the invention
Problem
The programming of traffic lights systems (TLS) in cities is a complex optimization problem. The majority of TLS in cities are controlled by electromechanical systems or microprocessors. Few systems are designed to control real-time TLS and to our knowledge no city can automatically control a major TLS in real time.
Generally, a programming plan for TLS is preprogrammed to during certain periods of the day and of the week (eg.. From 15:00 to 18:00). This plan is subsequently applied over several years - sometimes over a decade. Moreover, even during peak periods, there are vehicles flow variations. This methodology can not take into account these variations because the arrival of vehicles is simulated by statistical methods as Poisson law. Semi-actuated or fully-actuated systems allow to change the duration of the cycles but they require the installation of detector loops under the pavement and these systems are not intalled throughout the network. In addition, there are significant costs to maintain these systems.
The current procedure recommended by the Institute of Transportation Engineers (ITE) for programming TLS is shown in Figure 1. This is a complex, lengthy and costly process that need to be revised regularly. This method is used in most public administrations and is still the most reliable method available. This method is done with historical data. It is from these historic data that engineers can determine wich circulation system programming to apply. This work is done by using specialized simulation softwares like SimTraffic, Paramics, AIMSUN, Vissim, etc. These software can model the network to test various optimization scenarios and provide performance measures (waiting time, means speed, lenght of queues, etc.). This is an iterative process that models the network under study and the circulation expert applies a variety of scenarios until he found a satisfactory solution. The solution that seems the best is then retained and is validated again before implementation on the site (Fine Tuning). Programming is carried out on one or many junctions. When the TLS plan is established it is kept unchanged for several years.
The key ingredient of the ITE process is based on the reliability of the data collected from the field. The goal is to count the number of vehicles that pass eat each intersection. It is generally necessary to send a technician on the field to manuually count the number of cars in each junction and in both directions. That task must be done for several days and for various hours of the day and week (rush hour in the morning to the afternoon, evening, weekends, etc.). These data represents the circulation flow that will be use during the simulation. It is a very approximate measure that is taken during a certain period of time. It is far from data measured in real time. Also it is not reprentative of the real situation because the simulation model must do some assumptions like the agressiveness of driver behavior. These data should be taken for several days to establish means and to ensure that it reflect as closely the reality. These studies are also complemented by origin-destination studies to know the path of each vehicules. These complementary studies can be done through surveys and by observations in the field. Other measures can also be obtained by installing vehicle counting loops sensors. These sensors are installed under the pavement and are used to count the number of vehicles which pass over the loop. Whenever a vehicle passes over the sensor, the meter records it.
The main problem of the actual process is that this is a long, expensive and imprecise process that must be repeated regularly to reflect the evolution and changes in traffic flow. ITE recommends revising the programming of TLS at every 3 to 5 years, but 35% of systems are not reprogrammed to over ten years. Tarnoff and Ordonez (2004) estimate that more than half of the systems in the US are not synchronized or poorly maintained.
Our invention
Our invention specifically relates to the data collection process. The invention consists of using Vehicular's ad hoc networks networks (VANET) to collect traffic data in real time and transmit them to a traffic management system. VANET is defined by the IEEE 802. lip standard. In VANET every vehicle acts as a node of a temporary network. Each vehicle can receive information from other vehicles every split second (0.1 sec) regarding their status in a range of about 300 meters. The information that circulates in the network are about speed, acceleration, distance between each vehicle, the braking system and so on. This information is transmitted to communication stations installed along the road - Road Side Unit (RSU) and relayed to a Base Station (see Figure 2). This is called a communication mode from vehicle to vehicle (V2V) and Vehicle to Infrastructure (V2I). VANET operates on a dedicated frequency spectrum (75 MHz bandwidth and 5.9 GHz allocated by governmental authorities). Furthermore VANET can operate in variable weather conditions (rain, fog, snow) and confidentiality of information is maintained.
The main reason why VANET was invented at the beginning of 2000 years is to improve safety on the roads. This is done by providing information to drivers on vehicles circulating in the network. There are many studies on VANET relating to the safety but there is little on the traffic management. We propose to use this technology to collect data and pass it to a system installed in a control center (Figure 3 and others). It will then be possible to use these data to test a variety of scenarios for programming TLS like circulation expert do actually. It will also be possible to use these data for other uses like urban studies. The method of data collection and the architecture of our system is described in the attached article (Vaudrin and Capus, Improving Traffic Lights Management Information Sytems Using Available by VANET presented in Germany at the SUMO Conference May 24, 2016).
As part of our claims, we suggest using an algorithm based on the occupancy rate of each segment. However, there are a plurality of algorithmic techniques that can be used (some more successful than others). Our invention allows to provide a more reliable and economically process to manage TLS that current practices. VANET is used in a few studies to manage TLS. However, it is for distributed systems that are different from what we offer. We have also attached an article that reviews the possible uses of VANET. No item proposes a method as accurate as ours to collect traffic data and to process it with actual methods or to do it in real time as we proposed with a centralized system.
Benefits of our invention
Our method is more accurate than conventional methods. Our invention will permit to collect data for simulations following the ITE process. Also, it is not necessary to do manual counting on the field or to install sensor and other expensive equipment like cameras and loop detectors. Data collection with our method is free and requires little maintenance.
The advantage of this invention is that it is possible to obtain a multitude of parameters and the data processing algorithm is left to the discretion of the public administration. A public administration will have the possibility to revise the programming plans as often as desired. Once a change is observed, it will be possible to quickly do a simulation without returning to the field to get new measures because the system will give them data in real time.
The method provides also the necessary ingredients to implement any algorithm that has been previously validated by simulation software. Eventually, this invention will permit to manage the entire network in real-time of a city. It will transmit data to the control center that will treat them with an appropriate algorithm and transmit the instructions using a dedicated Internet network to a wireless devices installed at each intersection. In our knowledge, this approach as never be describe as we do. Our invention is sufficiently detailed to allow a public administration to implement it while using its own working methods.
This method also allows to be used in other contexts, for urban planning studies, transport planning or to simulate the exit of special events (sporting, cultural, festivals, parades, etc.). It also allows programming a system in real time with any efficient algorithm that exists or to be developped.