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Li G.-F.,Beihang University | Li G.-F.,China Aerospace Science and Technology Corporation | Chen L.-D.,China Aerospace Science and Technology Corporation | Tang G.-S.,China Aerospace Science and Technology Corporation | Zhang L.-Y.,China Manned Space Engineering Office
Yuhang Xuebao/Journal of Astronautics | Year: 2011

A mathematical model for the rendezvous launch window based on the rendezvous multi-constraints including orbit sunlight constraint, sunlight incidence constraint for optics navigation measurement devices and coplanar constraint is established in this paper. The method and the scheme of the rendezvous launch window were presented and the effects of every constraint on the rendezvous launch window are analyzed. The sets of annual rendezvous launch windows of both target and chaser under sunlight constraint are constructed. According to two mission programming modes, methods for determining the annual coplanar launch time sets for both target and chaser are also proposed. The day window and the time window of the annual rendezvous launch window sets with multi-constraints are plainly presented for analysis and programming of the rendezvous launch windows. Simulation computations indicate that the set of annual rendezvous launch windows is correct and valid. The model, the method and the result for the rendezvous launch window are benefit to analysis and programming of the rendezvous mission. Source


Zheng A.,Science and Technology on Aerospace Flight Dynamics Laboratory | Zheng A.,China Aerospace Science and Technology Corporation | Sun J.,Science and Technology on Aerospace Flight Dynamics Laboratory | Sun J.,China Aerospace Science and Technology Corporation | And 3 more authors.
Zhongguo Kongjian Kexue Jishu/Chinese Space Science and Technology | Year: 2014

The Unified S-band System (USB) is the main TT&C (Telemetry, Tracking and Command) network used in space missions including manned spacecraft and lunar exploration programs of China. Firstly, all kinds of errors existed in the USB range and range-rate measurements were analyzed, and the error correction models of tropospheric refraction delay, ionospheric delay, time tag bias, phase center error, channel delay and satellite ephemeris error were presented. Secondly, the accuracy of the USB measurements was evaluated and obtained based on the residual analysis of the USB range and range-rate measurements of a real space mission. Finally, according to the current actuality of disposal and application of USB measurements, some advices that should be noted in data processing were put forward. The conclusions have important reference value to improve the accuracy of orbit determination based on the USB system of China. Source


Zhong Z.-Y.,China Manned Space Engineering Office | Zhang H.-L.,China Manned Space Engineering Office | Zhang W.-M.,Shanghai JiaoTong University | Liu Y.,Shanghai JiaoTong University
Optical Engineering | Year: 2016

As a unique type of driving force, the transverse optical gradient force has been extensively studied and applied in the nanowaveguides resonator. Recently, it is demonstrated that the optical forces in slot waveguides of hyperbolic metamaterials can be over two orders of magnitude stronger than that in conventional dielectric slot waveguides. To investigate the nonlinear dynamic characteristic of hyperbolic waveguide resonator driven by optical gradient force, a continuum elastic model of the optoresonator is presented and analytically solved using the methods of Rayleigh-Ritz and multiple scales. The results show that the optical force is strengthened with the increase of the filling ratio of silver in the hyperbolic waveguide. The resonance frequency becomes greater with the increase of the filling ratio of silver no matter what the geometric parameters and physical property parameters are. However, the steady maximum vibration amplitude becomes smaller, and the degree of system stiffness softening also reduces. © 2016 Society of Photo-Optical Instrumentation Engineers (SPIE). Source


Zhong Z.-Y.,China Manned Space Engineering Office | Zhou J.-P.,China Manned Space Engineering Office | Zhang H.-L.,China Manned Space Engineering Office | Zhang T.,Shanghai University of Engineering Science
Computers and Structures | Year: 2016

Small deflections and moments exist on the boundaries of the flexible supports of MEMS cantilever-based sensors. The qualitative dynamical behavior is significantly affected by the non-ideal boundary conditions. Based on the Boussinesq's and Cerruti's displacement equations and the principle of energy equivalence, rigorous theoretical solutions of the normal, tangential and rotational equivalent stiffness are presented in this paper. The proposed model is validated by the fact that the theoretical results remained a good situation consistency with the reported experimental data. The variations of the equivalent stiffness with the geometric dimensions of the cross section of the flexible supports are investigated. It is observed that when the "Hard material" is used as the supports' materials, e.g. Silicon carbide, the equivalent stiffness is large. Yet the equivalent stiffness is small for the "Soft material", e.g. Silicon and Poly-silicon. In addition, by employing the method of multiple time scales, the non-dimensional differential partial equation of the motion as well as coupled boundary conditions are analytically solved. The results indicate that the resonance frequencies decrease with the flexible supports, however, increase due to the nonlinearity mechanical spring. © 2016 Elsevier Ltd. All rights reserved. Source


Zhong Z.-Y.,China Manned Space Engineering Office | Zhou J.-P.,China Manned Space Engineering Office | Zhang H.-L.,China Manned Space Engineering Office | Zhang W.-M.,Shanghai JiaoTong University | Meng G.,Shanghai JiaoTong University
International Journal of Heat and Mass Transfer | Year: 2016

As an inherent energy dissipation mechanism, the thermoelastic damping (TED) imposes an upper limit on the quality factors of microresonators. On the basis of Hamilton principle, the governing equation of solid-liquid-thermal coupling vibration of fluid-conveying microresonator is deduced. For different thermal boundary conditions, the analytical expressions of TED are separately derived by solving the heat diffusion equation of the thermal flow across the fluid-conveying microbeam. The results show that the liquid in the hollow microbeam has significant impact on TED. The natural frequency decreases with the increase of the flow velocity or axial pressure. However, both for the two proposed fluid-conveying models, TED increase with the increase of the flow velocity or axial pressure. The peak value of TED of the proposed models is larger than the hollow beam, but smaller than the solid beam. As a function of channel geometry, beam properties and flow velocity, the second peak is about to occur for the fluid-conveying beam. In addition, different from the results of the hollow beam and the low flow velocity models, the peak value of TED in the high flow velocity model increases monotonously with the increasing ratio of channel width to channel height due to the great area of heat convection between the inner channel and the fluid. © 2015 Elsevier Ltd. Source

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