Patent ID: 7277834
Filing Date: 2007-10-02
Classification: F41G

Abstract:
1. A method for estimating at least one of position and orientation of a mobile element disposed within a motion box, said mobile element coupled to at least one electromagnetic (EM) field sensor, said motion box including an EM field radiator for generating an EM field in said motion box, the method comprising the procedures of: (i) measuring at least one current EM field measurement of said EM field in said motion box, with said least one EM field sensor; (ii) generating adapted estimates of EM field model parameters by minimizing, with respect to said EM field model parameters, the difference between at least one periodically updated EM field measurement of said at least one current EM field measurement and an EM field model function, where said EM field model function is continuously updated using adapted estimates of said respective at least one of position and orientation; (iii) generating said adapted estimates of respective at least one of position and orientation by minimizing, with respect to said at least one of position and orientation, the difference between said at least one periodically updated EM field measurement and said EM field model function, where said EM field model function is continuously updated using said adapted estimates of EM field model parameters; (iv) providing estimates of said at least one of position and orientation of said at least one EM field sensor, by minimizing with respect to said at least one of position and orientation, the difference between said at least one current EM field measurement and said EM field model function, where said EM field model function is periodically updated using said adapted estimates of EM field model parameters; and (v) determining at least one of position and orientation of said mobile element according to said estimates of said at least one of position and orientation of said at least one EM field sensor.