dErrordetection and correction based on time space judgement of data captured by VLPR system
                                                                 LIU Qing hui1, XU Wei2, DONG Hong zhao1
(1.ITS Joint Research Institute Zhejiang University of Technology,Hangzhou 310014, China；2.Traffic Police Detachment of Hangzhou,Hangzhou 310014, China)

Abstract: Aiming at the problem that complex application background of license plate recognition equipment, the recognition rateis vulnerable to light, license plate fouling and blocking, vehicle speed and other factors, there are wrong license plates information in the collected data, the method of improving the recognition accuracy of VLPR was analyzed. Based on the data collected from license plate recognition devices，a method of error detection and correction was proposed for license plate recognition. First the average travel speed of road based on the captured data was calculated and wrong license plate by time space judgement was detected. Then character of wrong license plate was replaced and the wrong license plate by time space judgement was corrected. Finally this method was validated in the big data collected from license plate recognition devices of Hangzhou and motor vehicle registration information data of Hangzhou.Besides,the experimental results were verified by video image data collected from license plate recognition devices.The results indicate that this method can detect the wrong license plate, improve the accuracy of data collected by VLPR system.

Key words: intelligenttransportation; vehicle license plate recognition(VLPR); character replacement; travel time