Research And DSP Design Car Alarm Fingerprint Identification System

Since the automobile safety has become growing seriously, this paper putforward an auto fingerprint identification anti-theft system using theTMS320C5509,which based on the study of the traditional and digital fingerprint thathas the characteristic of uniqueness and invariability. With the capacitive fingerprintsensor of MBF200, we can achieve the algorithm of fingerprint identification in theDSP and feed the results back to the MCU using serial ports. This paper first focuseson circuit design of each hardware module, and put forward the design of the systemprogram based on the detailed analysis of the theory of the algorithm about fingerprintidentification. The main work of this paper can be summarized as follows:(1)Discussed the capacitive fingerprint sensor of MBF200, including thedesign of the peripheral circuit. Make sure that the system can accept the high-qualityfingerprint image so that the algorithm of fingerprint identification can beaccomplished smoothly. The typical DSP chip TMS320C5509which applied to imageprocessing is introduced, also the power circuit design, the JTAG interface circuitdesign and the external SDRAM interface circuit design. Meanwhile, with theanalysis of different methods for the interface circuit of DSP and Flash, it put up anew way to work for that. In the respect of interface between DSP and MCU, itfulfilled the serial communication based on the study of the McBSP, so that thecomplexity of the circuit has been reduced in the situation of lower data size, whichimproved the system more efficiency.(2)In the respect of algorithm of fingerprint identification, the orientation fieldand the gradient field has been worked out at the beginning of the following algorithm.After the equilibrium, the convergence and the smooth algorithm of the image, thefingerprint image has been intelligently enhancement using the characteristics ofwavelet function with the orientation field and the gradient field. Instead of using thegray level histogram, the binaryzation of image has realized by the property of theorientation field so that the algorithm is more adaptable. In the module of the imagealignment algorithm, it has built the array template of the fingerprint feature point andintroduced the model of the variable boundary box to alignment the fingerprint.(3)The design scheme of the software system has been put forward and theprocess flow of the DSP and MCU is given. It also debugged and analysis the hardware part and the software part. In the end, the evaluation indicators of thisalignment is given with the analysis of the software.