design of the license plate recognition platform based on the dsp embedded system-凯发官网入口

vol. 3, no. 9 modern applied sciencedesign of the license plate recognition platform based on the dsp embedded systemzhikun zhang & qilan huangschool of electrical engineering & automatic, tianjin polytechnic university, tianjin 300160, china abstract the license plate recognition system (lprs) is a very important development direction of the intelligent transportationsystems (its). with the development of the society and the enhancement of human living level, the amount of vehicle increases continually and the traffic status is deteriorating gradually, which brings large pressures for the society and the environment. the increasingly crowded city traffic needs more advanced and effective traffic management and control. it has been an important research direction to utilize the license plate recognition technology to enhance the management level and the traffic efficiency, and implement safe intelligent transportation management. in this article, the design, implementation and optimization of the dsp license plate recognition system which takes the tms320c6201 of ti corporation as the core chip were introduced. in this system, the video frequency (vf) decoding chip first translates the analog tv image signals obtained from ccd into the digital image signals which are inputted into dsp through fifo buffer by the control of cpld, and then aiming at the image, dsp performs the license plate positioning, the license plate character segmentation, the license plate character identification, the optical aberrance emendation, the nonlinear emendation of speed error and other algorithm operations to obtain the result of the license plate identification. keywords: license plate recognition, tms320c6201, cpld, ccs1. research meanings and actuality of the license plate recognition systemin recent years, the license plate recognition system in china has entered into the stage of application, but because ofthe influences of many numerous factors such as the particularity and the technology in chinese license plate, the using effect of the license plate automatic recognition system is not satisfactory, so the license plate recognition technology needs to be further enhanced. there are few products which can ensure that the recognition rate exceeds 95% and the recognition time is less than 0.5s. on the other hand, most current products are based on the application program of pc, so there costs are generally high. table 1 shows some data of the license plate recognition system used in china at present.its is a kind of modernized traffic management system which can perform real-time monitoring to the road traffic flowinformation, supervise and perfect the traffic status in time, implement various real-time traffic controls rapidly and duly according to the dynamic change of the traffic flow, lighten the crowded degree of the road, reduce the running delay of the traffic vehicles and the probability of traffic accident, ensure the safety and high efficiency of the traffic, enhance the using rate and the security of the system resources, and reasonably utilize relative traffic establishments. with the development of the traffic industry, its is gradually emphasized by various countries and governments, and it has been widely applied in the collection and statistics of traffic information, the communication among vehicles, the management of park and the non-parking charge. the roads and the parks gradually develop to the directions such as informationization, intelligentization and self-service management, which requires higher intelligent degree for the instruments, especially for the charge roads parks, the self-service management should be extended. so it is very important to establish exact license plate recognition for confirming the vehicle identity and establishing corresponding database management system. in recent years, many countries begin to try out the non-parking charge system and the park self-service management system which mainly adopt the wireless communication measure, but for so many vehicles which have not installed the communication instruments, the costs are very high, in addition, the phenomena that the wireless cards don’t accord with the vehicle information often happen. to solve these problems, some countries used the vidicon to record the images and adopted the manual observation to recognize the vehicles, which made the self-service management system to need large numbers of manual assistant works instead. to enhance the work 78