Control and manage traffic light system with VANET

Abstract

The programming of traffic lights systems (TLS) in cities is a complex optimization problem. The main problem of the actual process is that this is a long, expensive and imprecise process that must be repeated regularly to reflect changes in traffic flow. The invention consists of using Vehicular's ad hoc networks (VANET) to collect traffic data in real time and transmit them to a traffic management system. VANET is currently defined by the IEEE 802.11p standard. We propose to use VANET in correlation with others techniques to control TLS. This invention will permit to program actual TLS more efficiently, manage a network in real-time and it will be possible to be used for urban planning studies, transport planning or to simulate the exit of special events (sporting, cultural, parades, etc.). It also allows programming TLS in real time with any efficient algorithm that exists or to be developed.

Claims

1. A method for programming traffic lights systems with data from vehicular ad hoc network VANET, said data are relatives to all the data available with the IEEE.802.11p standard; and said standard can be modified, adapted, updated, renamed or replaced over time by the responsible authorities, said method comprises the following steps: a. choose a wireless medium to transfer said data from vehicles connected by the VANET, b. transfer said data from vehicles connected by the VANET to a Traffic Control Center in real time at a minimum frequency of 0.1 seconds, c. select a traffic light signals optimization algorithm, d. process said data with said traffic light signals optimization algorithm, e. use a secure communication system between said Traffic Control Center and said traffic lights, f. use traffic control devices installed at road network intersections to control said Traffic Lights Systems, g. send the instruction as a signal provided by said traffic light signals optimization algorithm through said secure communication system towards said traffic control devices to modify the traffic light signals programs in real time, said method permit to provide accurate road traffic data in a simple, practical and economical way to manage the Traffic Lights Systems in real-time and to make traffic simulation analysis as needed.

2. The method of claim 1 is used to manage said Traffic Lights Systems during events.

3. The method of claim 2 wherein said events are included sporting events, concert events, festival events, parades events, special events, construction works, detour roads or manifestations.

4. The method of claim 2 wherein said Traffic Control Center gives comprehensible and essential information to traffic officers who control the traffic during said events.

5. The method of claim 1 or 2 wherein said Traffic Lights Systems are static control systems.

6. The method of claim 1 or 2 wherein said Traffic Lights Systems are adaptive semi-actuated systems.

7. The method of claim 1 or 2 wherein said Traffic Lights Systems are adaptive fully-actuated systems.

8. The method of claim 1 wherein said data are transferred by means of communication towers.

9. The method of claim 1 wherein said traffic lights signals optimization algorithm is based on an average occupancy rate of each road segment.

10. The method of claim 1 wherein said communication system is a dedicated internet network.

11. The method of claim 1, wherein said communication system is a wireless communication system.

12. The method of claim 1 is used to make urban studies and to plan transportation studies.

13. The method of claim 1 wherein said data are used in a traffic circulation simulator in order to analyze traffic phenomena.

14. The method of claim 1 wherein said data are used to process traffic information at said Traffic Control Center and transmit messages to vehicle drivers to adjust driving behaviour so that vehicles can move more smoothly to improve traffic flow and mobility.

15. The method of claim 1 wherein said data are used to process traffic information from said Traffic Control Center and to transmit signals to autonomous cars in order to improve traffic flow.

16. The method of claim 1 is used to process traffic information from the Traffic Control Center, to transmit messages to drivers, to transmit signals to autonomous cars, to modify the programming of traffic lights, to control systems at the entrances, to exit motorways in order to improve traffic flow.

17. The method of claim 1 is replacing the need to collect traffic data manually, by sensors or by others means to adjust actual Traffic Lights Systems according to the current methods in force.

18. The method of claim 1 wherein said secure communication system is an optical fiber.

19. The method of claim 1 wherein said secure communication system is a secure mean.

20. The method of claim 19 wherein said secure mean is encrypted.

21. The method of claim 20 wherein said secure mean is a recognized and valid secure method.

Description

BRIEF DESCRIPTION OF DRAWINGS FIGURES

(1) FIG. 1 is a plan of a signal timing environment from the Prior Art.

(2) FIG. 2 is a view of a vehicular ad hoc network (VANET) system.

(3) FIG. 3 is a view of the current invention.

(4) FIG. 4 is a view of the current invention also used to help traffic officers to control circulation.

(5) FIG. 5 is a view of the current invention used to stock data and use them to program the current TLS.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(6) In the following description and in the accompanying drawings, the numeral numbers refer to identical parts in the various Figures.

(7) FIG. 1 shows a signal time process plan 18 from the Traffic Signal Timing Manual published by the “Institute of transportation engineers”, 2009. The figure shows the process to be realized in order to develop, to program and to implement current traffic lights systems (Static or adaptive with detection loops). This process respect the norms, standards, rules, transport laws, specific local considerations, operations and maintenance rules, and internationally recognized methods for traffic control and TLS.

(8) FIG. 2 shows how VANET (Vehicular's Ad hoc NETwork) works, there are three kinds of intercommunications: inter-vehicle communication 22,22′ each vehicle can receive information from other vehicles every split second (0.1 sec or less) regarding their status in a range currently of about 300 meters. This information is transmitted 24,24′ to communication stations (Road Side Unit—RSU) installed along the road, it is a vehicle-to-roadside communication. And the stations along the road RSU relayed information 26 to the base Station 30 (inter-roadside communication).

(9) These data are about speed, acceleration, the braking system and so on. This information is much more accurate than the data collected by the usual methods (for example by manual counting, detection loop or origin-destination survey). There are also 25 which is a signal between police communication towards drivers, 25′ which is a police communication towards a RSU, and 25″ which is a police communication towards the base station 30.

(10) FIG. 3 shows the method 20 of the present invention used to command the traffic light; each vehicle is sending data 22,22′ to others vehicles on the road or 24,24′ to RSU 28, the data is transferred to the computer control center 34 which operates an algorithm 38 producing signals 40,40′ used to respectively program the traffic signals 36,36′. The first steps are those of VANET: the data 22,22′ provided and exchanged by each vehicle are sent 24,24′ to road side unit antenna 28, and the road side unit antenna send a signal 26 to the base station 30. The base station sends a signal 32 to the control center 34.

(11) FIG. 4 shows the method of the present invention used to manage circulation during events, such as sport events, cultural, parades, construction perturbation, manifestations and so on; the computer control centre 34 analyze the data 32 received by the base station 30 and send signals 40,40′ to each traffic officers 42,42′ in order to manually conduct traffic during events. One also sees inter-vehicle communication 22, 22′, each vehicle can receive information from other vehicles every split second (0.1 sec or less) regarding their status in a range of about 300 meters. Said information is transmitted 24 to road side Unit 28 installed along the road, and the road RSU relayed information 26 to the base Station 30 (inter-roadside communication) which transferred it 32 to the computer control center in order to provide a signal which permits to manually conduct the traffic during non-functioning of the TLS.

(12) FIG. 5 shows a data base symbol 44, in the control center 34, the traffic data 32 provided by the base station 30 are stored in the data base 44, the data and can be used for example in a simulator to do simulation or to program TLS as it is currently done for static and adaptive systems. Those data can also be used for urban studies. One also sees inter-vehicle communication 22, 22′, each vehicle can receive information from other vehicles every split second (0.1 sec or less) regarding their status in a range of about 300 meters. Said information is transmitted 24,24′ to communication stations, road side units (RSU) installed along the road, it is a vehicle-to-roadside communication. And the RSU relayed information 26 to the base Station 30 (inter-roadside communication), which transferred it 32 to the computer control center and in the database 44. The data base is used to stock data and to do simulation with those data as is currently done for static and adaptive systems. Those data can also be used for urban studies.

SUMMARY OF THE INVENTION

(13) The present invention is a method for programming traffic lights signals (TLS) by using data provided by vehicular ad hoc network, VANET abbreviated, the system or method comprises the following steps:

(14) a. choose a wireless medium to transfer said data from vehicles connected by the VANET system,

(15) b. transfer the data from VANET to a computer control centre that operating an algorithm used to intervene in the programmation of the traffic lights system. These data may be transferred by means of a radiocommunication tower towards the computer control center and/or by road side units. The frequencies of the transfer could be those approved according to the current norm IEEE.812.11p as in the operations of VANET. These standards can be modified, adapted, updated or replaced over time by the responsible authorities of VANET.

(16) c. Process the data with the algorithm. An algorithm based on the average occupancy rate of each road segment could be use for example, but any accurate algorithm can also be use at the choice of the city, government agency or public administration.

(17) d. Construct a secure communication system between the computer control centre and the traffic lights system. A dedicated internet network or a wireless communication are secure communication systems which could be use at this stage.

(18) e. Install wireless devices at each intersection of the road which command the traffic lights. These traffic lights system may be static, semi-actuated, or fully-actuated as the actual systems.

(19) f. Send the signal provided by the algorithm through the secure communication system towards the wireless devices.

(20) With the present invention the risks of signal loss are minimal. The present invention permits to get data at any time. These data are relatives to speed, acceleration, brake system, and all data available by VANET standard. These data from VANET can be transferred to the computer control centre in real time at a minimum frequency of 0.1 seconds. These data makes it possible to program the currents TLS according to the process recommended by the Institute of Transportation Engineers (FIG. 1). These data and this system also makes it possible to control a TLS in real time.

(21) The present invention is used to manage traffic lights during events, such as sport events, cultural, parades, construction perturbation, or manifestations. A decision-making center is established in order to give comprehensible and essential information to traffic officers who control the traffic during the events. The present invention could also be used to make urban studies and to plan transportation studies.

(22) The data provided by VANET can be stored in a data base 44, and used in a simulator to represent actual traffic flow and driver's behaviour more accurately than current assumptions based on statistical laws (for example Poisson's Law).

(23) The data are used to process traffic information at the computer control center or traffic control center and transmit messages to vehicle drivers to adjust their car driving behaviour so that vehicles can better circulate synchronously thus promoting the fluidity of the circulation as a whole.

(24) The data are used to process traffic information from said computer control center and transmit signals to autonomous cars in order to adjust their speed and promote traffic flow.

(25) The data are used to process traffic information from the computer control center and to transmit signal to TLS to modify the programming of traffic lights in order to promote fluidity of the traffic as a whole.

(26) The present invention is used to process traffic information from the control center, to transmit messages to drivers, to transmit signals to autonomous cars, to modify the programming of traffic lights, to control systems at the entrances, to exit motorways, to facilitate the flow of traffic. The present invention is replacing the need to collect traffic data manually, by sensors or others means to program static traffic lights systems according to the methods in force.

(27) In the present invention the norm IEEE 802.11p can be modified, adapted, updated, renamed or replaced over time by the responsible authorities of VANET.

(28) In the present invention the norm IEEE 802.11p is modifiable, the norm can be adapted, updated, renamed or replaced according to the rules of international standardization bodies that may be different in some countries or regions of the world (whatever the name is given to the standard or the norm in relation to VANET).

(29) It is to be clearly understood that the instant description with reference to the annexed drawing is made in an indicative manner and that the preferred embodiments described herein are meant in no way to limit further embodiments realizable within the scope of the invention. The matter which is claimed as being inventive and new is limited only by the following claims.

PARTS

(30) 18 Prior Art, the signal timing process 20 Method of the present invention 22, 22′,22″,22′″ Inter-vehicle communication 24,24′,24″,24′″ vehicle-to-roadside communication 25 Police communication towards drivers 25′ Police communication towards roadside antenna 25″ Police communication towards base station 26,26′ Roadside-to-base station communication 28,28′,28″,28′″ Roads side antennas or Road Side Unit—RSU 30 Base Station 32 Signal 34 Control center 36,36′ Traffic signals 38 Algorithm 40 Signal produces by the algorithm 42,42′ Traffic officers 44 Data base symbol