A method for airbourne transfer alignment of an inertial measurement unit

摘要

A method for determining the initial conditions for an inertial measurement unit (IMU) of a second vehicle launched from a wing of a first vehicle is provided. The method includes the steps of defining a state vector x as including (a) the rotation zeta of the computed coordinate axes with respect to the real coordinate axes of the second vehicle and (b) the projection delta a along the Z axis of the first vehicle of the rotation of the second vehicle from its nominal coordinate axes to its real coordinate axes. A measurement z is defined as the projection delta beta of a rotation angle beta , along the Z axis of the first vehicle, between the nominal coordinate axes and a current computed coordinate axes. The method also includes the steps of estimating x over time with a Kalman filter, wherein the projection delta beta is the measurement vector and the state vector x changes only due to random noise and processing x to produce the attitude about the Z axis of the first vehicle.