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This paper studies the finite time attitude control of a satellite with flexible appendages when the velocity measurements are not available in the condition of external disturbances and model uncertainties. First a dynamic model which considers the coupling effect between the motion of the rigid hub and the deformation of the flexible appendages is build. Then a terminal sliding mode observer is...
The six-degrees-of-freedom relative motion tracking control of a rigid spacecraft is investigated in this paper. In view of the model uncertainties and external disturbances, the relative coupled translational and rotational dynamics are modeled with the aid of the exponential coordinates on the Lie group SE(3). Then, a fast terminal sliding mode controller is designed to make sure the tracking control...
In order to effectively reduce the volume, mass and cost of the attitude measurement unit (AMU) of the satellite, as well as to ensure that the reliability of the whole system is proper, this paper presents a hardware design method of AMU based on multiple MEMS gyroscopes. Using the modular design method, the scalability of system and the interchangeability between modules are effectively improved...
This paper presents the Lyapunov-based decentralized adaptive control scheme for a laser beam steering system with a piezo-electric mirror. This controller which this paper designs effectively solves the problem that the piezoelectric steering system is complex dynamics and can not know state of controlled plant. The system uses a decentralized control technology which decouples the interaction of...
The problem of attitude tracking control for rigid satellite is studied in this paper. Based on the dynamic equation and kinematics equation using error quaternion and error angular velocity, a sliding mode controller is initially designed to solve this problem. In order to avoid inherent chattering of sliding mode control and then improve control effect, a disturbance observer is introduced and included...
This paper presents an adaptive model reference scheme for laser-beam steering by an acousto-optic steering system which is a novel nonmechanical control system. The controller this paper designs effectively solves the optical communication system performance worsening problem because of the nonlinearity and the parameters drift of the acousto-optic devices and the pointing error of the satellite...
The paper presents a quaternion-based attitude control algorithm which is subject to control input constraints for rigid spacecrafts. Lyapunov theory is employed to prove the global asymptotic stability of the zero equilibrium points of the close loop system. Also the algorithm is validated by the corresponding hardware-in-the-loop (HIL) simulation using a single-axis air bearing table and other hardware...
The computation of image motion velocity is the premise of high resolution optical imaging. To solve this problem, the model of image motion velocity for spaceborne cameras is established in this paper. The positions of a target and the pixel plane are expressed in the camera coordinate system based on five coordinate systems and multiply coordinate translations. The calculation formulas of target...
Based on the RTPS protocol and the NDDS network messaging middleware, a distributed real-time simulation network of satellite system is developed with Constellation software. Considering the structure feature of actual satellite, the module decomposition technique of distributed simulation is discussed in this paper. And with the RTPS protocol and NDDS network middleware, a synchronous control of...
This paper bases on three micro-satellites which formationally fly on a same orbit and perform three dimension solid mapping for terra. The calculating formula of LEO formation-flying satellite inter-satellite links is guided according to the special require of formation-flying micro-satellite inter-satellite links. A new communication project, which changes code rate according to the inter-satellite...
Safety is a crucial requirement of On-Board Computer (OBC) design of a satellite, especially for the new type OBC--takes FPGA as central processor. Upon that this paper proposes a plan of FPGA OBC design and adds hierarchical fault tolerant concept to enhance the reliability of the OBC system. The fault tolerant architecture can be divided into three hierarchic ranks, containing single-CPU reconfiguration,...
In this paper, every composing of MicroSim is introduced, and the work theory of each composing is also introduced. One of the executive machines of MicroSim (reaction wheels) is used to realize the damping mode of micro-satellite. The task of the damping mode is to stop the rotational motion of the microsatellite in each of the three axes. And the simulation result is given under the damping control...
The content of this paper is a subtask of Nation-863 High Tech Item. Two micro-satellites perform formation-flying and inter-satellites communication demonstration test in a circular orbit. The optimizing design method of space circular formation order based on mend heredity algorithmic is given; the method can ensure formation order steadily for a long time under various absorb impetus. The inter-satellite...
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