نتایج جستجو برای Attitude

تعداد نتایج: 49804  

2012
Joanna C. Hinks, John L. Crassidis,

An attitude determination covariance measurement model for unit vector sensors with a wide field-of-view is analyzed and compared to the classic QUEST covariance model. The wide field-of-view model has been previously proposed as a more realistic alternative for sensors where measurement accuracy depends on angular distance from the boresight axis. Both QUEST and the wide field-of-view models a...

2005
Yong Li, Jianping Yuan,

The vectorized algorithms for GPS based attitude determination can be equivalent to a two-level optimal estimation problem. In the first level estimation the GPS carrier phase measurements can be converted to the vector observations in a sense of least squares. The second level estimation is the Wahba’s problem which describes how the attitude matrix can be derived from the vector observations....

Journal: :CoRR 2011
Mikael Carmona, Olivier J. J. Michel, Jean-Louis Lacoume, Nathalie Sprynski, Barbara Nicolas,

Sensor network attitude problem consists in retrieving the attitude of each sensor of a network knowing some relative orientations between pairs of sensors. The attitude of a sensor is its orientation in an absolute axis system. We present in this paper a method for solving the sensor network attitude problem using quaternion formalism which allows to apply linear algebra tools. The proposed al...

2011
Zhongkui Li, Zhisheng Duan,

This paper addresses the distributed attitude synchronization problem of multiple spacecraft with unknown inertia matrices. Two distributed adaptive controllers are proposed for the cases with and without a virtual leader to which a time-varying reference attitude is assigned. The first controller achieves attitude synchronization for a group of spacecraft with a leaderless communication topolo...

2013
Lina Wang, Zhi Li,

This paper proposed a nonlinear robust control for spacecraft attitude based on passivity and disturbance suppression vector. The spacecraft model was described using quaternion. The control law introduced the suppression vector of external disturbances and had no information related to the system parameters. The desired performance of spacecraft attitude control could be achieved using the des...

2012
Gabriele Giorgi, Peter J. G. Teunissen,

The GNSS (Global Navigation Satellite Systems) are a valid aid in support of the aeronautic science. GNSS technology has been successfully implemented in aircraft design, in order to provide accurate position, velocity and heading estimations. Although it does not yet comply with aviation integrity requirements, GNSS-based aircraft navigation is one of the alternative means to traditional dead-...

2012
Shifeng Zhang, Shan Qian, Lijun Zhang,

The capability of attitude maneuvers and attitude tracking for spacecrafts is required in the current sophisticated space missions. In short, it is to obtain command requirements and attitude orientation after some form of control. With the development of space missions, the ability of rapid and energy-saved large-angle attitude maneuvers is actively expected. And the high requirements for the ...

Journal: :Journal of Ayub Medical College, Abbottabad : JAMC 2008
Nisar Nusrat, Zehra Nishat, Haider Gulfareen, Munir Aftab, Naeem Asia,

OBJECTIVE To determine the knowledge and attitude of women towards menopause and to investigate the symptoms experienced by postmenopausal women. DESIGN It was a cross sectional survey based on sample of convenience. PLACE AND DURATION OF STUDY Study was conducted at out patient department of Isra university hospital from 1st January 2005 to 31st December 2006. METHODS Total 863 women of ...

Journal: :Int. J. Systems Science 1999
Dejan M. Boskovic, Miroslav Krstic,

2004
John L. Crassidis, Stephen F. Andrews, F. Landis Markley,

In this paper, several attitude estimation designs are developed for the Tropical Rainfall Measurement Mission (TRMM) spacecraft. A contingency attitude determination mode is required in the event of a primary sensor failure. The final design utilizes a full sixth-order Kalman filter. However, due to initial software concerns, the need to investigate simpler designs was required. The algorithms...

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