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The image technology of the spacecraft offers useful information variously: weather, geography and military intelligence. Recently, demands of the image which have higher accuracy and degree of precision are rapidly increased. In this sense, scan mirror-gimbal system is implemented on the image observation devices to compensate the image error. The dynamics of the scan mirror-gimbal system and main...
This paper presents the design of algorithms to estimate the mass property, specially the moment of inertia, for the gyroless spacecraft. The gyro has several problems such as high price and frequent breakdown, but the other sensors could not replace gyro because of its update rate. However, CMOS-APS-based star tracker which is recently developed can give the vector observations in high update rate...
A lunar orbital capture guidance law is presented for a spacecraft with electrical propulsion system using Lyapunov feedback control approach. Construction of the Lyapunov function candidate is based on orbital elements which consist of angular momentum and eccentricity vectors. Unlike the orbit transfer problem between closed orbits, the lunar capture problem has two constraints. One thing is that...
A steering law design for single gimbal control moment gyros (CMGs) for spacecraft attitude control is addressed. The novel approach for the new steering law has a close relevance to the well-known singularity robustness method combined with the null motion approach. The proposed predicted singularity robustness (PSR) approach ultimately leads to an optimized solution of gimbal rates with performance...
The momentum transfer control of a rigid spacecraft with two momentum wheel actuators is investigated using feedback linearization technique focusing on very small nutation angle as a performance index. The equations of motion are transformed to a general linearized form by feedback linearization, including a guarantee of internal dynamics stability. It is known that the configuration of inertia properties...
This paper deals with attitude dynamics estimation and rate sensor calibration of spacecraft at the same time during a designed maneuver. This study has been motivated from that both estimation of the moment of inertia and calibration of gyros for precision attitude control are usually performed by a pre-designed 3-axis maneuver for them, respectively. Spacecraft attitude dynamics to be estimated...
In this paper, a ducted fan Uninhabited Aerial Vehicle(UAV), being capable of vertical take-off and landing, is studied to understand characteristics and control of the vehicle. The ducted fan UAV is unstable and susceptible to wind due to its external structural shape. Also the ducted fan UAV must change the attitude to gain speed, so it has different characteristics with respect to velocity. To...
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