Analysis And Implementation Method Research On Immobilizer

Immobilizer is a kind of automobile anti-theft technology. By recognizing ignition key's ID, it control engine whether it can be started. The car in the market mostly installs the Immobilizer. This technology develops quickly in these years, and now is a hot field in the automotive electronics.Low-frequency antenna design, electromagnetic interference design, information security technology are the key technology of Immobilizer. This paper discusses how to solve these problems by analysis, simulation and experiments, and meets the demand of the project.At first, this paper describes the status of the automobile anti-theft technology, discusses the principle and work requirement of Immobilizer. It researches on the structure and workflow of Immobilizer, then under specific automobile environment, raises the work and function requirement.Secondly, this paper discusses low-frequency antenna design, electromagnetic interference design, information security technology, and the ideas for solving the problems. About the low-frequency antenna design, it firstly notes the principle of antenna, then gives the design on the antenna figure, antenna radius, tuning circuit parameter and so on. After the low-frequency antenna design, it gives the design about avoiding the power interference and electromagnetic induction interference, and tests the PCB with the special equipment. About the information security technology, it gives a improved encryption algorithm which is based on DES(The Data Encryption Standard). This kind of improved encryption algorithm meets either the requirement of security or the requirement of real-time which DES can not meet.At last, validate all system performance of Immobilizer on the bench, the result show that low-frequency antenna design, electromagnetic interference design, information security technology all reach the system's requirement.