VEHICLE-FIXED COMPONENT INERTIAL GUIDANCE SYSTEM STUDY,

摘要

The general structure of a vehicle-fixed component inertial navigation system is outlined. The portion of the computation problem pertaining to the computation of direction cosines relating two rotating coordinate frames is discussed,and the differential equations satisfied by the direction cosines is derived. A brief description is given of the principal problems encountered in the vehicle-fixed operation of components. Three algorithms for the computation of direction cosines in the single-axis case are derived. The direction cosine differential equation is solved by expansion in series and three-axis algorithms defined specialization of the correct solution. The noncommutativity problem is discussed and a method suggested for reducing errors resulting from noncommutativity. The algorithms applicable to single-axis motion are specified and combined with simple assumptions on vehicle motion,to yield sets of difference equations. The difference equations are solved and the errors in the direction cosines plotted against functions proportional to time. The requirements of special-purpose computers designed to implement the three-axis algorithms are outlined and the general organization,and the parameters,of several computers,is given. (Author)