Modeling of spacecraft with flexible solar panel considering thermally induced motion
Thermally induced motion of flexible solar panel have significant impact on attitude dynamics and control when the spacecraft experience eclipse transitions. Based on angular momentum theorem thermally induced attitude dynamics of rigid hub with a flexible solar panel is developed. The principle of thermally induced vibration is explained. Thermally induced disturbance toque which initiates attitude error of control system is obtained. Flexible modal response is analyzed with different position of solar panel when satellite enter or exit eclipse. Numerical simulations illustrate that thermally induced disturbance toque mainly distort yaw and roll axis attitude of spacecraft.
THERMAL SNAP DISTURBANCE IDENTIFICATION VIA IN -FLIGHT DATA
Thermal ly induced deformations of flexible appendages have long been one of the largest disturbance source s for earth orbiting satellites . A number of attempts have been made to characterize these disturbances but to date there is no universal model that can accu rately extend to new solar wing designs. This paper introduces a novel approach for identify ing the size of the snap disturbance based on in -flight telemetry data and statistically quantifies them into models for new space missions. This novel identification algorithm uses in flight telemetry data and processes it through an inverse model of spacecraft dynamics to derive the snap disturbance torque. This paper describes the identification algorithm, numerical result s a nd modeling process to predict new in -flight thermal snap transient s. In particular, this method was used to extend the snap torque model from a previously -launched satellite with 5 -panel solar wings to a new one with 6 panel wings. The prediction matched up excellently with on -orbit data. .
Looking for regional words in late seventeenth-century England: Bishop White Kennett and his glossary to Parochial Antiquities (1695) 1
The analysis of regional dialects in the Early Modern period has commonly been disregarded in favour of an ample scholarly interest in the ‘authorised’ version of English which came to be eventually established as a standard. The history of regional ‘Englishes’ at this time still remains to a very great extent in oblivion, owing mainly to an apparent dearth of direct textual evidence which might provide trustworthy data. Research in this field has been for the most part focused on phonological, orthographical and morphological traits by virtue of the rather more abundant information that dialect testimonies yield about them. Regional lexical diversity has, on the contrary, deserved no special attention as uncertainty arises with regard to what was provincially restricted and what was not. This paper endeavours to offer additional data to the gloomy lexical setting of Early Modern regional English. It is our aim to give a descriptive account of the dialect words collated by Bishop White Kennett’s glossary to Parochial Antiquities (1695). This underutilised specimen does actually widen the information furnished by other well known canonical word-lists and provides concrete geographical data that might contribute to bridging the gaps still existing in the history of lexical provincialisms at the time.