Patent ID: 7650252
Filing Date: 2010-01-19
Classification: G01C

Abstract:
1. A system for sensing the inclination of element with respect to gravity, said element defining orthogonal X and Y axes, and a Z axis orthogonal to both said X and Y axes, said element being rotatable about an axis of rotation extending parallel to said Z axis, said element being supported by and rotatable with a platform, comprising: an inclinometer, mounted on said element at a location spaced from said axis of rotation by a distance r, for providing inclinometer outputs indicating acceleration in the X and Y directions, designated as I a sensor, mounted on said platform, for sensing the rotational speed w of the element about said axis of rotation and providing a sensor output indicating said rotational speed W, a circuit for differentiating said sensor output to determine the angular acceleration of said element dw/dt, a circuit for multiplying said angular acceleration by the value r to determine the tangential acceleration of said element at said point where said inclinometer is mounted r(dw/dt), a circuit for resolving the tangential acceleration of said element at said point where said inclinometer is mounted to determine the X axis component thereof, and for resolving the tangential acceleration of said platform at said point where said inclinometer is mounted to determine the Y axis component thereof, and a circuit for subtracting said X axis component of said tangential acceleration of said element at said point where said inclinometer is mounted from said acceleration I