Statistical and Worst Case Evaluation of Orbital Jitter Reduction Using Passive Damping
Report Number: WL-TR-91-3078 Volume II, pages EAA-1 to EAA-10
Author(s): Molnar, J., Hill, D., Stahle, C.
Corporate Author(s): GE Astro Space Division
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 10
DoD Project: 2401
DoD Task: 240104
Identifier: This paper is part of a conference proceedings. See ADA241312
Abstract:
The jitter responses of a damped and undamped precision mounting platform (PMP) are compared. The primary response is due to a platform mounted sensor which slews back and forth as it scans. The sensor torque profile is reduced to Fourier components, and the proximity of the platform resonances to the input frequencies is evaluated. If the resonance is close to a Fourier component, the mode is shifted to the Fourier frequency and the worst case jitter is computed. If the worst case response exceeds the jitter allowable, the limits above and below the Fourier frequency for shifting the mode that produces responses in excess of the allowable is determined. Then, assuming a Gaussian probability density function for the natural frequency, the probability of jitter exceedance is computed. Results show dramatic reductions in orbital jitter from the use of passive damping. Significant weight reduction is also achieved for the PMP analyzed with passive damping.
Provenance: University of Colorado Colorado Springs, Kraemer Family Library
Author(s): Molnar, J., Hill, D., Stahle, C.
Corporate Author(s): GE Astro Space Division
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 10
DoD Project: 2401
DoD Task: 240104
Identifier: This paper is part of a conference proceedings. See ADA241312
Abstract:
The jitter responses of a damped and undamped precision mounting platform (PMP) are compared. The primary response is due to a platform mounted sensor which slews back and forth as it scans. The sensor torque profile is reduced to Fourier components, and the proximity of the platform resonances to the input frequencies is evaluated. If the resonance is close to a Fourier component, the mode is shifted to the Fourier frequency and the worst case jitter is computed. If the worst case response exceeds the jitter allowable, the limits above and below the Fourier frequency for shifting the mode that produces responses in excess of the allowable is determined. Then, assuming a Gaussian probability density function for the natural frequency, the probability of jitter exceedance is computed. Results show dramatic reductions in orbital jitter from the use of passive damping. Significant weight reduction is also achieved for the PMP analyzed with passive damping.
Provenance: University of Colorado Colorado Springs, Kraemer Family Library
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This report is part of the following conference:
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Proceedings of Damping '91: 13-15 February 1991 San Diego, California (EAA-1 through GBC-16)
WL-TR-91-3078 Volume II