Development Of Portable Face Detection And PIR Signal Acquisition System

With the development of society and the advancement of technology, people’sliving standard has been improved a lot. Under such circumstances, their requirementsfor home safety are much higher. As a consequence, it has become people’s urgentneeds to develop a reliable and cost-effective home-used integrated security systemwhich contains the face detection and pyroelectric infrared signal analysis. Portability isa huge problem for security products, and it is also the most urgent problem forconsumers to solve., Users can monitor their property anytime and anywhere, which issafer and more convenient because of the portability of the system.With the trend ofhigh-tech products’ popularizations, smart phones have become an integral part ofpeople’s life. Based on this platform, the design of portable security products has greatlypractical significance.As an important part of the face recognition, the face detectiontechnology combines the face detection system with smart phones together, makingcellphones a running platform for face detection and achieving the combination of smartphones and security technology, which is the new development direction of securitytechnology in future. Android smart device has been the major mobile terminalequipment recently, such as telephones,TV, watches, washing machines and otherelectrical equipments have used the Android operating system. However, The securityof users’ personal information has always been hackers’ main attacking target, whichrestricts the development of relevant technologies and have a bad influence on themarket of relevant equipments.Therefore, in this thesis, the study on the store ofpeople’s personal information is conducted deeply, and it is combined with facedetection technology so as to be co-ported to the Android operating system-based smartphones, which has a great practical significance in promoting the popularity of securitytechnology.Pyroelectric infrared (PIR) is a passive infrared detectors, which can induceelectrical signals toward infrared signals of organisms. The PIR has such advantages asthe stable performance, cost-effectiveness, high-hiding quality, and low requirementsfor illumination, hence, it has won broad support in the wave of security products’coming into the average family. However, its further development has been restricted bythe high mistake and failure rate.PIR detector and the face detection system which runson the mobile devices are combined so as to make up the PIR detector’s defects that it results in mistakes, and cannot collect images, or produce records when it detectsintrusion.Studies of this thesis are conducted on the following tasks:①This thesis investigates several main smart phone operating systems home andabroad, and finally chooses the Android operating system as the system softwareplatform through comparing their exploitability and penetration, together with people’sactual needs. This thesis carries out some pioneering researches on the knowledge ofstoring personal information, at the same time, personal images and personal phonemanagement are put into the system design.Besides, programming experimental testsare done to the SQL database, users’ information acquisitions are stored, and theinterface and query capabilities are also optimized. As the first difficulty of the system,its operation is stable and reliable.②As the configuration of some hardware devices isn’t the same as that of othersand the face detection algorithm consumes a large amount of computation,cost-effective mobile devices sometimes are unable to meet the needs of the systemrunning on memory and processor. This thesis compares the main face detectionalgorithms and chooses the AdaBoost algorithm suitable for mobile devices as therelevant algorithm of face detection module in this system. Moreover, this algorithmconstantly revises probability parameters through training the weak classifiers, andimproves the correct rate of detection results through cascading the strong classifiers. Inthis thesis, the system has been optimized so that the low-configuration mobile devicescan satisfy the requirements of face detection system. Besides, this thesis also uses twokinds of facial feature extraction methods in experiment, and then programs them in thesystem according to their different characteristics. In order to test the validity of eachmethod, a lot of contrastive experiments are conducted in this thesis.③In this thesis, the theory of PIR detector has been given a deep analysis. Basedon the previous algorithm studies and the demand of actual experiment, this thesis alsodesigns and implements the PIR signal acquisition system, and builds a database forPIR signal, which makes a significant contribution to other teamwork.④This thesis implements the Android operating system-based face detectionapplication and personal information storage application, which is conducted throughthe coordination design of the portable face detection system and pyroelectric infraredsignal acquisition system, and comprehensive researches, as well as the orderlyexploitation of the hardware platform. In addition, Combined with the PIR signal acquisition system, this thesis also meets the requirements of portability,cost-effectiveness, easy operation and popularization and so on.