Patent ID: 8260477
Filing Date: 2012-09-04
Classification: G01C,G01M

Abstract:
1. An apparatus for tracking a center of gravity of an air vehicle, comprising: a primary set of sensor assemblies oriented for dynamically measuring at least one flight parameter and generating primary signals corresponding thereto, the primary set being adapted for measuring the flight parameter along three mutually orthogonal axes of an aircraft; a redundant set of sensor assemblies oriented for dynamically measuring the same flight parameter as the primary set of sensor assemblies and generating redundant signals corresponding thereto, the redundant set being adapted for measuring the flight parameter along the same three mutually orthogonal axes of the aircraft as the primary set of sensor assemblies; a signal processor connected to the primary and redundant sensor assemblies, the signal processor having: signal sampling means for sampling the primary and redundant signals from the sensor assemblies at predetermined time intervals; center of gravity processing means for forming a primary estimate of the center of gravity of the aircraft from the primary signals, means for forming at least one redundant estimate of the center of gravity from the redundant signals, and means for filtering out unreliable sensor signals and combining the primary and at least one redundant estimates to obtain a corrected estimate of the center of gravity at the predetermined time intervals; guidance and control parameter processing means for dynamically calculating guidance and control parameters from the corrected center of gravity at the predetermined time intervals; and means for high speed communication of the calculated guidance and control parameters to a flight guidance and control processor; wherein said center of gravity processing means for forming said primary or redundant estimate comprises: means for solving angular rate of change state equations, including: where Ω x , Ω y , and Ω 7 are the x-angular velocity, y-angular velocity and z-angular velocity respectively, μ is the constant distance between said sensor assemblies and a point about which said sensor assemblies are symmetrically disposed A x1 , A x2 , A x3 , A x4 , are signals from x-oriented sensors placed on a first point, a second point, a third point, and a fourth point, respectively, A z1 , A z2 , are signals from z-oriented accelerometers placed on the first and second points, respectively, and A y3 and A y4 , are signals from y-oriented sensors placed on the third and fourth points, respectively; and means for comparing right-hand sides and left-hand sides of a set of angular rate state equations, the angular rate state equations being: where the right-hand side is evaluated based on a result of the angular rate of change solving means, A z3 , A z4 , are signals from z oriented accelerometers placed on the third and fourth points, and the A y1 , A y2 are signals from y-oriented sensors placed on the first and second points, respectively and, at least one annular ring adapted for mounting on the aircraft, said primary set of sensor assemblies and said redundant set of sensor assemblies being symmetrically mounted on the annular ring.