In order to study the influence of flywheel micro vibration on the imaging of a high resolution optical satellite, the flywheel components disturbance model was established, and the flywheel components were tested. The analysis of the measured data shows that there is a series of harmonic at the first order frequency 50Hz, and a series of peaks around the 190Hz and 280Hz. The integration of the angular displacement response that was obtained by exerting the unit sine excitation on the satellite and the flywheel measured disturbance data shows that there is a lot of angular displacement harmonic response frequency in 40Hz~80Hz and 230Hz~280Hz, the maximum angular displacement resonance response amplitude is 2.739" along the vertical direction, the angular displacement resonance response amplitude is 2.617" at 245Hz and 2600rpm, and 0.5" magnitude harmonic amplitude around 245Hz. Flywheel micro vibration has a great influence on the high resolution optical satellite imaging quality. Suggestions on further research on micro vibration of flywheel are proposed.
According to the picture of a sub-meter resolution optical satellite acquired on the orbit, there is a phenomenon of jitter in the process of taking pictures. The flywheel as the main attitude control component of the satellite, the disturbance that it caused has great influence on the high resolution optical satellite in its normal action. This paper has respectively researched the flywheel components’ disturbance mechanism from three parts, including uneven rotator, rotator friction, bearing disturbance, builds the mathematics model of disturbance to analysis the characteristic of disturbance. we get that the vibration system is not a fully linear system, the system is linear before the occurrence of rubbing. It also can be seen that the system has a number of different cross rigidity, it will often appear unstable motion that resulting in damage, or becomes the ultimate destruction due to the role of nonlinear damping. When the rolling roll in the surface, it will produce an alternative excitation force if there exist defects or damage in the rolling surface. This research would offer guidance for system optimization design and vibrating isolation compensation of the later type of improved satellite.
There are three main nonlinear elements in the large mirror assemblies, which are screw pretension, adhesive stress and
state changes in the assembly process. The optical shape will be influenced seriously by these factors. But the impacts
will not be shown in linear analysis results, because as the simplification, these factors have been ignored. The nonlinear
analysis method for predicting optical surface deformations resulted from assembly process is discussed in detail. Take a
typical mirror support structure for example, the nonlinear analysis model was established. Comparing the calculation
results with the optical shape test, it is illustrated that nonlinear analysis is more accurate and closer to the test result.
And according to the simulation result, the bowl-shaped depression which was discovered in the test can also be
Each disciplinary has its own modeling and analysis tools to solve its own specific field problems. In order to achieve
integrated simulation of high precision space optical systems and predict optical performance respective to the
mechanical and thermal loads, data must pass through different analysis tools. Simulation tools used in the thermal,
structural and optical design process and the relationship among them were first depicted and the integrated simulation
methods were described in detail. Zernike polynomial fitting methods and interpolating approaches were also
demonstrated. Because of the orthogonality of Zernike polynomials, it was not probably used in some situations such as
noncircular apertures and discrete data, and the coupling of Zernike polynomial coefficients and other methods were also
introduced in the paper. The toolkit OMTIA (Optical, Mechanical and Thermal Integrated Analyzer) based on the
methods was developed, which appears as an indispensable tool for engineering practice.