Study On Helmet Tracker Utilizing A Position Sensitive Detector

This dissertation is an exploration for the technology of helmet tracking utilizing a position-sensitive detector (PSD). It is involved with the theory of helmet tracking and PSD, mathematical model of helmet tracking, and corresponding practical implement technology. The key techniques and problems to realize the helmet tracker are studied in theory and practice, while the implement scheme of helmet tracker is the aim of the research. This thesis mainly consists of the following parts. Firstly, the actuality of helmet tracking technology in the world is introduced. The related fundamental theories and key techniques to the study are elaborated. The theory, characteristics and analysis method are also introduced. The application of PSDs being used in helmet tracker is proposed. All of the above works are the basis for the following research. Secondly, two mathematical models of helmet tracker based on one PSD camara, four infrared LEDs are proposed, one is two DOF model and the other is six DOF. The analytical expressions of parameters according to the two models are also presented. Thirdly, the hardware experimental facility is established in order to validate the model of helmet tracker. Based on the experimental facility, the two models are tested and the results show that the proposed models of helmet tracker are fully practicable. Finally, detailed error analysis process for the models of helmet tracker is carried out. The results show that the main causes that affect the accuracy of helmet tracking system are the integrated imaging resolution ratio and the magnitude of Signal to Noise Ratio (SNR). They affect the system and random error respectively. So, the system accuracy of helmet tracker can be improved if we increase the integrated imaging resolution ratio and the magnitude of SNR.