SECOND ORDER COMPLEMENTARY BLENDING FILTER FOR GLOBAL POSITIONING SYSTEM/INERTIAL NAVIGATION SYSTEM

摘要

A second-order filter that blends accurate position information from a one source, and velocity information from another source, both suitably scaled, in a second-order complementary filter. The filter is arranged such that an internal integrator (106) maintains a value that represents the difference in the rate of change of the accurate position information, and the velocity input of the other source. This velocity difference is applied to another integrator (114) outside the filter, whose initial condition is the position error between the two sources to the second order filter. The output of this latter integrator (114) is a correction signal that grows at a rate equal and opposite to the rate of error built-up of position data from the source whose velocity is used in the second order filter. This correction signal is summed (120) with the original position signal. In addition, the output of the second order filter may be used as a highly accurate position signal.