In this paper, we consider the periodic robust controller for attitude control of satellites in low-earth orbit (LEO). An 3-axis Magnetic torquer is assumed to be the only actuator available for the control task. The ...
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ISBN:
(纸本)9780889868571
In this paper, we consider the periodic robust controller for attitude control of satellites in low-earth orbit (LEO). An 3-axis Magnetic torquer is assumed to be the only actuator available for the control task. The proposed linear periodic control scheme is based on a periodic modeling of the Earth's magnetic field. Deviation of the actual geomagnetic field from the nominal model is considered as structured uncertainty that satisfies an integral quadratic constraint. The proposed controller is, therefore, robust against input torque uncertainty which is suitable for practical application. The control scheme has been verified via a computer simulation. A scenario where a small satellite is orbiting in circular LEO environment is assumed. The results show that the performance of the proposed periodic controller is better than conventional optimal controller both on error suppression ability and less power consumption.
The electromagnetic torquer is the most common method to generate torque for attitude control of low earth orbit (LEO) small satellite. Due to power consideration, an actuator saturation is one of serious problem in p...
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ISBN:
(纸本)9789746724913
The electromagnetic torquer is the most common method to generate torque for attitude control of low earth orbit (LEO) small satellite. Due to power consideration, an actuator saturation is one of serious problem in practice. In this paper, we propose the scheme to design the robust controller to stabilize a satellite attitude by considering the actuator saturation as a structured uncertainty which is based on integral quadratic constraint. The proposed robust controller is of linear time varying controller that has similar structure as conventional linear quadratic regulator (LQR). The simulation results show that our proposed robust controller outperforms an LQR controller.
In autonomous navigation systems, localization is the most important problem to be solved. In this note, we propose the algorithm to localize an unmanned ground vehicle (UGV) equipped with a global positioning system ...
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ISBN:
(纸本)9789746724913
In autonomous navigation systems, localization is the most important problem to be solved. In this note, we propose the algorithm to localize an unmanned ground vehicle (UGV) equipped with a global positioning system (GPS), an odometer and an electronic compass. The proposed scheme is based on the unscented Kalman filter (UKF). To improve the accuracy and robustness, the novel noise model of data from an electronic compass is incorporated in the system modeling. The performance of our simple algorithm is evaluated by the experimental results that strongly confirm the benefit even during GPS outage in some short period of time.
A nonlinear controller structure for an overhead crane is designed and implemented on a crane plant. The energy based stabilizing controller part is derived by the method of controlled Lagrangians. In that framework, ...
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How to make vision system work robustly under dynamic light conditions is still a challenging research focus in computer/robot vision community. In this paper, a novel camera parameters auto-adjusting technique based ...
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This paper applies an optimal control approach to an hydraulic system. An approach is proposed to use an open-loop control on the model of a real hydraulic system. The approach uses a feedback control, to create a clo...
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We establish the sound absorption mode of micro-nano aperture membrane material according to the classic porous media acoustic theory and cylindrical shell model theory and considering the viscous resistance theory an...
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We establish the sound absorption mode of micro-nano aperture membrane material according to the classic porous media acoustic theory and cylindrical shell model theory and considering the viscous resistance theory and the heat conduction theory as well. Comparing the theoretical result obtained by simulating the sound absorption property through Matlab and the experimental result, we prove the validity of the mode and it conforms to the sound absorption law of the porous material. We predict the Acoustic Propagation roperties of ordered mesoporous thin film using this mode and find the absorption coefficient is very small and the absorption property of the micro-nano aperture membrane is poor.
A novel direct-drive rotary-linear switched reluctance motor (RLSRM) is proposed. The motor has the advantages of robust mechanical structure, low manufacture cost and capability of operation under hostile environment...
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The on-line least-square identification method is applied for the linear switched reluctance motor (LSRM) based closed-loop control system. Since switched reluctance motors have severe nonlinear characteristics, on-li...
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Since research and development in nanotechnology and precision engineering has progressed rapidly, a reduction of rotating errors of an ultra precise spindle is required. However, the conventional spindle measurement ...
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ISBN:
(纸本)9781617820199
Since research and development in nanotechnology and precision engineering has progressed rapidly, a reduction of rotating errors of an ultra precise spindle is required. However, the conventional spindle measurement requires some technique to separate the spindle error motion from the artifact form error. Also the application with sub-nanometer order is questionable. In this research, the new technique to measure the spindle radial motion error using the atomic encoder is proposed. In this paper, the principle of measurement, design concept of the instrument, and some experimental results of the 2-D atomic encoder will be discussed.
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