EP0119810A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Nutation damping
Assignee: BAE Systems PLC
•
Filing: 1984-03-12
•
Granted: —
•
Expires: 2004-03-12
Abstract
Abstract An active nutation damping system for a spacecraft may comprise a nutation sensor controlling an actuator, a thruster say, via a control system so as to produce nutation opposing torques. Following the realisation that performance limits on known systems may be due to a simplistic dynamic analysis which assumes the spacecraft to be a rigid body when it may in fact comprise one or more oscillatory elements, for example a fuel tank in which fuel is able to «slosh» about freely, the damping system herein is operable to identify two types of nutation component, for one of which appropriate opposing torque components are generated while, for the other type, torque components are generated that, at first sight, would appear to increase the nutation components but which, in fact, improve the overall nutation damping performance.
Inventors
- 👤 Peter Richard British Aerospace P.L.C. Scott
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:55
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/24; B64G1/28; B64G1/281; B64G1/244; B64G1/38; B64G1/36
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
146 words
An active nutation damping system for a spacecraft, the system comprising sensor means for supplying a time varying signal indicative of nutation of the spacecraft, actuating means for applying a compensatory torque to the craft, and signal processing means for controlling the actuating means to cause the application to the craft of time varying nutation reducing torque having Fourier frequency components corresponding to respective Fourier frequency components of the sensor signal, the processing means being such as to differentiate between a first and a second class of said components with the or each sensor waveform component belonging to one class having a first phase relationship with the corresponding torque waveform component, and the or each sensor waveform component belonging to the second class having a second phase relationship with the corresponding torque waveform component, the first and second phase relationships being substantially opposite to one another.
Claim 2
Dependent Claim
146 words
An active nutation damping system for a spacecraft, the system comprising sensor means for supplying a time varying signal indicative of nutation of the spacecraft, actuating means for applying a compensatory torque to the craft, and signal processing means for controlling the actuating means to cause the application to the craft of time varying nutation reducing torque having Fourier frequency components corresponding to respective Fourier frequency components of the sensor signal, the processing means being such as to differentiate between a first and a second class of said components with the or each sensor waveform component belonging to one class having a first phase relationship with the corresponding torque waveform component, and the or each sensor waveform component belonging to the second class having a second phase relationship with the corresponding torque waveform component, the first and second phase relationships being substantially opposite to one another.
Claim 3
Dependent Claim
166 words
An active nutation damping system for a spacecraft, the system comprising sensor means for supplying a time varying signal indicative of nutation of the spacecraft, actuating means for applying a compensatory torque to the craft, and signal processing means for controlling the actuating means to cause the application to the craft of time varying nutation reducing torque having Fourier frequency components corresponding to respective Fourier frequency components of the sensor signal, the processing means being such as to differentiate between a first and a second class of said components such that the component of the angular velocity of the satellite body about a transverse axis as determined by each sensor waveform of the first class is substantially opposite in phase to the corresponding torque waveform about the same axis, and the component of the angular velocity of the satellite body about a transverse axis as determined by each sensor waveform of the second class is substantially in phase with the corresponding torque waveform about this axis.
Claim 4
Dependent Claim
166 words
An active nutation damping system for a spacecraft, the system comprising sensor means for supplying a time varying signal indicative of nutation of the spacecraft, actuating means for applying a compensatory torque to the craft, and signal processing means for controlling the actuating means to cause the application to the craft of time varying nutation reducing torque having Fourier frequency components corresponding to respective Fourier frequency components of the sensor signal, the processing means being such as to differentiate between a first and a second class of said components such that the component of the angular velocity of the satellite body about a transverse axis as determined by each sensor waveform of the first class is substantially opposite in phase to the corresponding torque waveform about the same axis, and the component of the angular velocity of the satellite body about a transverse axis as determined by each sensor waveform of the second class is substantially in phase with the corresponding torque waveform about this axis.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.