GUN LAUNCHABLE INERTIAL NAVIGATION SYSTEM GLINIS

Development of an Inertial Measurement Unit (IMU) for a low cost miniature gun launchable Inertail Navigation System (INS) to be packaged within a 60 mm projectile is prosed. The IMU sensor cluster design proposed is based upon the inertial silicon sensors produced by Waddan Systems. A pair of the silicon accelerometers are mounted together with their input axes coincident. Each is excited by an equal but opposite velocity normal to the input axes. This velocity has no effect on the acceleration sensed if the pair is put in a pure linear acceleration field, because each senses the same acceleration component. But when it is subjected to an angular rate normal to both the input axis and the velocity vector, the coriolis acceleration experienced by each is equal but opposite. Thus, by taking the sum and difference of the outputs of the devices one can measure both the linear acceleration and the angular rate. A minimum of three such pairs in a sensor cluster would yield a three axis IMU. The objective of the Phase I effort is to design an IMU which is analytically as well as technologically feasible for the 60 mm projectile application.