The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 20, 1978
Filed:
Oct. 21, 1975
Harold A Rosen, Santa Monica, CA (US);
Jeremiah O Salvatore, Redondo Beach, CA (US);
Hughes Aircraft Company, Culver City, CA (US);
Abstract
A motor active nutation damping system employing a rotor mounted accelerometer, a platform/rotor relative rate sensor, a despin motor and a controller. In the presence of nutation, the accelerometer senses a sinusoidal acceleration whose amplitude is proportional to nutation angle and whose frequency is rotor nutation frequency, i.e., the rate at which the transverse angular momentum vector appears to rotate in rotor fixed coordinates. The controller multiplies the filtered accelerometer signal by a square wave at relative rate generated by the relative rate sensor to obtain a signal consisting of sinusoids at platform nutation frequency and higher order frequencies. Since platform nutation frequency is the rate at which the transverse angular momentum vector appears to rotate in platform fixed coordinates, spin axis torque appropriately phased at this frequency and applied to a dynamically imbalanced platform generates a transverse reaction torque that reduces the transverse angular rate associated with nutation. The controller accomplishes this function by appropriately filtering and amplifying the modulated signal, and then commanding a torque to the despin motor proportional to the resulting signal.