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Star-sensor has an excellent capability of providing high accurate attitude, which depends on the accuracy of location to a large extent. At present, star-sensor is restricted by the accuracy of its location information which is normally given by Initial Navigation System, but this location information involves non-ignorable inaccuracy due to the accumulated error. In prior research, star-sensor needs...
The use of a barometric pressure sensor in a wearable fall detector has been shown to improve the detection accuracy by determining the altitude change associated with the fall event. However, the barometer is a high-power-consuming sensor. This paper proposes a fall detection approach using a hermetically sealed and waterproof enclosure incorporating a small window covered by a semi-permeable membrane...
Developing real-time simulation systems by manual programming is a relatively complex, unreliable and costly process. In order to overcome the problems above, real-time simulation systems of the model of orbital transfer vehicle (OTV) were designed in two ways based on xPC Target and mix-programming of LabVIEW/SIT and MATLAB/Simulink, respectively in this paper. Both methods not only had little requirement...
Fuzzy Multi-objective Decision-Making (FMODM) was applied to select blasting parameters and establish fuzzy matrix for the objective functions; minimum weighting relative deviation distance method was adopted to optimize the design scheme which not only agrees with the engineering requirements, but also can cut the cost as much as possible. The optimized scheme was compared with an actual engineering...
A discontinuous control law is proposed to achieve global asymptotic stabilization for oscillators with bounded delayed input. Only the “position” signal is used to generate the piecewise constant control signal. The asymptotic stability is analyzed by Poincaré Map method and conditions are proposed. The effectiveness of this control law is verified by simulation studies.
Using aerodynamic force to finish the orbital transfer mission can save a lot of fuels and increase the payload. In this paper, After giving the mathematical description of the Aero-assisted Orbital Transfer(AOT) problem, we discrete it through the Guess-pseudospectral method and then apply SNOPT algorithm to get the optimal state trajectory. After that we do some simplify to original dynamic equations...
A so called sliding-backstepping controller for attitude maneuver in some large flexible satellite is put forward. Further, combined with theory of Extended State Observer (ESO), the controller has been improved to estimate and compensate the uncertainties. After the stability analysis, simulation was carried out in particular using Single Gimbal Control Moment Gyros (SGCMGs) as the momentum actuator...
This paper proposes a networked sliding mode controller for servomechanical systems. Asymptotic stability is analyzed. Saturation function is used to eliminate chattering. Sensitivity of the zero eigenvalue with respect to the gain of the saturation function in linear interval is analyzed. Conditions for the choice of the gain and time delay are proposed. Simulations are conducted to verify the theoretical...
The line-of-sight (LOS) stabilization control based on gyro stabilized platform is required to isolate LOS from the movement and vibration of carrier and ensure pointing and tracking for target in electro-optical tracking system. In this paper, a fractional-order PI (FOPI) controller is applied in the design of stabilization loop of LOS stabilization system for the first time, based on the analysis...
The strains of an arbitrary point on the resonator of the hemispherical resonator gyro are deduced under Kirchhoff-Lyav hypothesis. The force equilibrium equations of the thin shell element are established on the basis of the calculated strains. When the gyro is subjected to three-axis angular rates and angular accelerations, the inertia force is calculated and the border motion equations of the hemispherical...
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