US4096427A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nutation damping in dual-spin stabilized devices
Assignee: Raytheon Co
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Filing: 1975-10-21
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Granted: 1978-06-20
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Expires: 1995-10-21
Abstract
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.
Inventors
- 👤 Harold A. Rosen
- 👤 Jeremiah O. Salvatore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:20
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/24; B64G1/36; B64G1/28; B64G1/281; B64G1/38
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
A nutation control system for a dual-spin stabilized device having a rotor, a platform, a despin motor, a relative rate sensor and a nutation sensor, in which the invention comprises a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply a torque to said device to reduce the amount of nutation.
Claim 2
Dependent Claim
93 words
A nutation control system for a dual-spin stabilized device having a rotor, a platform, a despin motor, a relative rate sensor and a nutation sensor, in which the invention comprises a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply a torque to said device to reduce the amount of nutation.
Claim 3
Dependent Claim
107 words
A nutation control system comprising: a dual-spin stabilized device having a rotor, a platform and a despin motor; a relative rate sensor disposed on said device for sensing the relative rate of rotation of said rotor and said platform; a nutation sensor disposed on said device for sensing nutation; and a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply torque to reduce the nutation.
Claim 4
Dependent Claim
107 words
A nutation control system comprising: a dual-spin stabilized device having a rotor, a platform and a despin motor; a relative rate sensor disposed on said device for sensing the relative rate of rotation of said rotor and said platform; a nutation sensor disposed on said device for sensing nutation; and a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply torque to reduce the nutation.
Claim 5
Dependent Claim
120 words
A nutation control system comprising: a rotor adapted to spin about a spin axis, a body rotatably coupled to said rotor, a despin motor disposed on said rotor and coupled to said body for controlling relative rotation, a relative rate sensor disposed on said rotor for sensing the relative rate of rotation, a nutation sensor disposed on said rotor for sensing nutation, and a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply torque to reduce the nutation.
Claim 6
Dependent Claim
120 words
A nutation control system comprising: a rotor adapted to spin about a spin axis, a body rotatably coupled to said rotor, a despin motor disposed on said rotor and coupled to said body for controlling relative rotation, a relative rate sensor disposed on said rotor for sensing the relative rate of rotation, a nutation sensor disposed on said rotor for sensing nutation, and a modulator coupled to the output of said relative rate sensor and to the output of said nutation sensor for modulating the signal from said nutation sensor with the signal from said relative rate sensor, the output of said modulator being coupled to said despin motor to cause said motor to apply torque to reduce the nutation.
Claim 7
Dependent Claim
185 words
A nutation control system comprising: a rotor adapted to spin about a spin axis, a body rotatably coupled to said rotor, a despin motor disposed on said rotor and coupled to said body for controlling the relative rotation of said body with respect to said rotor, a relative rate sensor for generating a aquare wave indicative of the relative rate of rotation of said body with respect to said rotor comprising a magnet disposed on said body and a pair of coils disposed on opposite sides of said rotor adjacent to the path of said magnet, an accelerometer for sensing nutation disposed on said rotor and aligned parallel to said spin axis and displaced therefrom the generating in response to nutation a sine wave at rotor nutation frequency, a filter coupled to the output of said accelerometer, a modulator coupled to the output of said filter and said relative rate sensor for modulating the sine wave from said accelerometer with the square wave from said relative rate sensor, and circuit means providing filtering and gain coupling the output of said modulator to said despin motor.
Claim 8
Dependent Claim
185 words
A nutation control system comprising: a rotor adapted to spin about a spin axis, a body rotatably coupled to said rotor, a despin motor disposed on said rotor and coupled to said body for controlling the relative rotation of said body with respect to said rotor, a relative rate sensor for generating a aquare wave indicative of the relative rate of rotation of said body with respect to said rotor comprising a magnet disposed on said body and a pair of coils disposed on opposite sides of said rotor adjacent to the path of said magnet, an accelerometer for sensing nutation disposed on said rotor and aligned parallel to said spin axis and displaced therefrom the generating in response to nutation a sine wave at rotor nutation frequency, a filter coupled to the output of said accelerometer, a modulator coupled to the output of said filter and said relative rate sensor for modulating the sine wave from said accelerometer with the square wave from said relative rate sensor, and circuit means providing filtering and gain coupling the output of said modulator to said despin motor.
References Cited (Backward Citations)
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Cited
US3830447A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-19 | 1981-12-19 | 1982-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-19 | 1985-12-19 | 1986-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-19 | 1989-12-19 | 1990-06-20 | $7700.00 | Window Closed / Lapsed |