California Partners for Advanced Transportation Technology

This report contains an evaluation of the sensing techniques and implementation issues of magnetic sensing as a position reference system. The field patterns of sample magnetic markers were first measured to illustrate the basic characteristics of such systems. Several sensing approaches were explained and compared with regard to their functioning principles and sensitivity to measurement variations. Three particular algorithms were discussed with illustrations of respective mapping methods. Robustness and sensitivity of the sensing methods, when subject to signal noises and parameter variations, are desirable features. A framework for dealing with technical limitations and objectives is outlined. The constraints and preferences of sub-systems and the corresponding issues are listed for further evaluation of described sensing systems. The optimization of such systems can only be accomplished by building the appropriate evaluation models for each component and the overall system. With the increasing deployment of magnetic sensing systems for position reference, these subjects deserve elaborated studies and thorough analysis. KEY WORDS: Magnetic, Sensing, Position Reference, Ground Vehicle Guidance and Control