Patent Publication Number: US-2010117864-A1

Title: Vehicle identification and speed detection method and system

Description:
REFERENCES CITED 
     U.S. Patent Documents 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                 3,522,611 
                 August 1970 
                 Maronde 
               
               
                 4,234,923 
                 November 1980 
                 Eshraghian 
               
               
                 4,866,438 
                 September 1989 
                 Knisch 
               
               
                 4,878,248 
                 October 1989 
                 Shyu 
               
               
                 5,204,675 
                 April 1993 
                 Sekine 
               
               
                 5,310,999 
                 May 1994 
                 Claus 
               
               
                 5,381,155 
                 January 1995 
                 Gerber 
               
               
                   
               
            
           
         
       
     
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
     Not Applicable 
     FIELD OF THE INVENTION 
     The present invention relates to vehicle traffic control, traffic surveillance, and more specifically to the detection and identification of vehicles whose speed exceeds a legal limit. 
     BACKGROUND OF THE INVENTION 
     The control and decreasing of speed limit violations is both a safety and traffic congestion issue. The number of highway accidents may be reduced if drivers obey the speed limits. On the other hand, traffic accidents are a major cause of traffic congestion. 
     At the present time the detection of vehicle speed is based primarily on such methods as Doppler radar, laser beam, sensing coils on the roadway (as in U.S. Pat. No. 4,234,923), or parallel infrared beams. All the said methods measure the vehicle speed only in a particular point of the road. In many countries, according to the law, such points must be clearly identified by signs and said points are well known by motorists. Therefore, the speeding vehicle can easily avoid a fine by decreasing their speed when approaching the measuring point. 
     In addition, most of speed detection devices require frequent calibration and calibration certificates are often required as evidence in court. In fact, in some cases the absence of a calibration certificate can help acquit an accused party. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a system and method to provide traffic surveillance and more specifically, the detection and identification of vehicles whose speed exceeds a legal limit anywhere for an extended part of the roadway. 
     The system consists of at least two detectors, installed on a roadway with known distance between each other. Each detector comprising means to identify the vehicle and to detect the exact time when the vehicle passes by. An average speed of the vehicle is calculated using the time difference of passing by the detectors and the distance between detectors. 
     The system can further detect if the vehicle is speeding and present relevant information, including the license plate number and photograph of the operator to police violation database or to a police officer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features of the present invention may be more fully understood with reference to the following detailed description taken in conjunction with the accompanying drawings: 
         FIG. 1  is a perspective view showing an appearance of the detectors installed along a roadway; 
         FIG. 2  illustrates a detailed block diagram of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The system consists of at least two detectors ( 11 ), installed on a roadway ( 10 ) with known distance between each other (L), and a computing unit ( 12 ) which collects information from the detectors, analyzes it, stores in the police database ( 14 ) or together with other vehicle registration information sends it to a police officer. 
     The detector detects and clearly identifies a vehicle, records the exact time of the vehicle passing by and optionally takes a photograph of the vehicle and the operator. The detection and identification could be performed by reading and recognition of a license plate number (for example as in U.S. Pat. Nos. 3,522,611, 4,866,438, 4,878,248, 5,381,155). Another method of identification is by means of electronic transponder widely used for automatic roadway toll charging system such as in U.S. Pat. Nos. 5,204,675 and 5,310,999. 
     The identities of the vehicles along with the time of passing by are being compared in the computing unit and an average speed of each vehicle is being calculated as: 
     V=L/(T 2 -T 1 ), where 
     V—average speed, 
     T 1 —the time of passing by the detector N, 
     T 2 —the time of passing by next sequential detector N+1, 
     L—the distance between the pair of detectors N and N+1. 
     If the average speed exceeds the limit, it is obvious that the vehicle has exceeded the speed limit at least for some part of the section of the road between detectors and at least it had the speed equal to V. 
     The relevant information, which may include identity of the car, average speed, license plate number, photograph of the vehicle, photograph of the operator is transmitted to a police officer or to a database and further may be used to issue traffic violation citations to the drivers of the vehicle or to collect traffic statistics.