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Wang X.-P.,Shanghai Electro Mechanical Engineering Institute
Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics | Year: 2013

Several separation trajectories of statically unstable air-to-air missile by rail launch were computed by combination of flow simulation based on N-S equations solver with 6-DOF motion equations of missile and control law. The computational results show that the pitching angles and the yawing angles of missile change rapidly, even the rolling angles are divergent quickly, due to the lateral aerodynamic interference from the aircraft, if no control strategy is adopted. While attitude control is introduced, missile attitudes during the separation from aircraft are steady, and safety on aircraft is greatly improved.

Xie L.,Northwestern Polytechnical University | Xu M.,Northwestern Polytechnical University | An X.,Northwestern Polytechnical University | Cai T.,Shanghai Electro Mechanical Engineering Institute | Chen W.,Northwestern Polytechnical University
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2013

To carry out research of nonlinear aeroelasticity, this paper presents a nonlinear time-domain aeroelastic simulation program which adopts computational fluid dynamics/computational structural dynamics (CFD/CSD) couple method. The program couples the nonlinear structural finite element software NASTRAN with a multi-block structured grid-based CFD solver developed by myself. Radial basis function (RBF) is used to transfer information between the two solvers and deform grid. To improve the efficiency of the RBF method, a space point reduction algorithm based on multi-level interpolation is constructed. For the purpose of reducing the number of space points, the interpolation object of each interpolation step is the error of previous step, and interpolation region is limited simultaneously. Results of some mesh deformation examples show that this way can support the movement of large deformation with high computational efficiency. With the use of this program, flutter computation of AGARD 445.6 wing is completed, static aeroelastic computation of a wing with a large aspect ratio is performed and a dynamic aeroelastic simulation of limit-cycle-oscillation (LCO) of a cropped delta wing is carried out. Results demonstrate that structural nonlinearity has strong influences on aeroelastic phenomenas when the aspect ratio of the wing is large or the amplitude of response is great.

Lai P.,Shanghai Electro Mechanical Engineering Institute | Lu Z.,Shanghai Electro Mechanical Engineering Institute
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2015

The hardware-in-the-loop simulation plays a very important role in the research and design process of missile weapons. The architecture of the hardware-in-the-loop simulation system for RF/IR compound guidance was introduced. The model of the passive-wave radar signal based on phase interferometry and the realizing schemes were researched. The hardware-in-the-loop simulation system, which simulated passive-wave radar by signal injection method, was proposed. Experiment results show that the algorithm design of RF/ IR compound Guidance can be tested with the effective support of this system. ©, 2015, Chinese Association for System Simulation. All right reserved.

Li C.,Harbin Institute of Technology | Li C.,University of Central Florida | Jing W.,Harbin Institute of Technology | Wang H.,Shanghai Electro Mechanical Engineering Institute | Qi Z.,Shanghai Electro Mechanical Engineering Institute
IEEE Transactions on Aerospace and Electronic Systems | Year: 2010

A new gain-varying algorithm for the three-dimensional pure proportional navigation (PPN) guidance problem is presented using the differential geometric (DG) guidance command. To this end, classical differential geometry theory is introduced, firstly, to transform and modify the DG guidance curvature command so as to facilitate the practical implementation and to avoid singularity of the guidance command. Then, a new gain-varying guidance scheme is developed using the modified DG guidance command, as well as the principle of the PPN guidance law, the new guidance law does not need the evaluation of time-to-go information. Furthermore, the capture analysis of the PPN-type guidance law is qualitatively studied in terms of the DG formulations, and a post-launch capture condition is derived and expressed in geometric terms. Simulation results demonstrate that the proposed guidance algorithm performs better than the conventional PPN guidance law in the case of intercepting maneuvering targets. © 2010 IEEE.

Hui F.,University of Jinan | Qin F.,Shanghai Electro Mechanical Engineering Institute
Proceedings - 2016 8th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2016 | Year: 2016

In GNSS/INS navigation integrated systems, the selection of inertial sensors is a factor which can impact their system performances implicitly. Unfortunately, the research of the relationship between the inertial sensor errors and the navigation performances is not sufficient yet. In this case, the mathematical relationship between the sensor quality and the INS (Inertial Navigation System) performance is firstly derived in details based on a 6 DOF (Degree of Freedom) model. Since the INS is a part of the GNSS/INS system, the influence of the sensor errors on the total performance is further analyzed. By simulating an integrated system using three different grade IMUs (Inertial Measurement Units), the influence mechanism is proved. © 2016 IEEE.

Liu C.,Shanghai Electro Mechanical Engineering Institute | Yang J.,Shanghai Electro Mechanical Engineering Institute | Ni Y.,Fudan University
Computers and Mathematics with Applications | Year: 2011

Poiseuille number of rarefied gas flow in channels with designed roughness is studied and a multiplicative decomposition of Poiseuille number on the effects of rarefaction and roughness is proposed. The numerical methodology is based on the mesoscopic lattice Boltzmann method. In order to eliminate the effect of compressibility, the incompressible lattice Boltzmann model is used and the periodic boundary is imposed on the inlet and outlet of the channel. The combined bounced condition is applied to simulate the velocity slip on the wall boundary. Numerical results reveal the two opposite effects that velocity gradient and friction factor near the wall increase as roughness effect increases; meanwhile, the increments of the rarefaction effect and velocity slip lead to a corresponding decrement of friction factor. An empirical relation of Poiseuille number which contains the two opposite effects and has a better physical meaning is proposed in the form of multiplicative decomposition, and then is validated by available experimental and numerical results. © 2011 Elsevier Ltd. All rights reserved.

Zhang J.,Jiangsu University | Zhao D.-A.,Jiangsu University | Wang M.,Shanghai Electro Mechanical Engineering Institute
Yuhang Xuebao/Journal of Astronautics | Year: 2011

A robust decoupling control method is presented for nonlinear attitude dynamics of hypersonic vehicle with model uncertainties and external disturbances. The dynamics is separated into fast loop and slow loop as attitude angular velocity and attitude angle in terms of the singular perturbation theory. In the outer-loop, the simple analytical control law based on second order model reference adaptive control theory is used to suppress the coupling of attitude kinematics and external disturbances without inverse operation. In the inner-loop system, the affine control with tight couping aerodynamic coefficients is used, control vector is solved explicitly by nonlinear dynamic inverse, the desired dynamics is in proportional plus integral dynamics form, trajectory linearization-aided time-varying controller is designed based on model predictive control policy with input constraint, to improve system robustness. Lastly, simulation result demonstrates effectiveness of the proposed method.

Fan J.,Shanghai Electro Mechanical Engineering Institute | Li L.,Shanghai Electro Mechanical Engineering Institute | Li W.,Tianjin Jinhang Institute of Technical Physics
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2015

Infrared countermeasure systems and technology have developed for half a century. Several types of infrared countermeasure systems, such as on-board infrared jamming system, infrared decoy and infrared smoke have appeared, and form a huge family of infrared countermeasure systems. In recent years, with the development of advanced infrared imaging guided weapons and technology, the jamming performance of traditional infrared countermeasure systems became more and more dissatisfactory. The technical concept of direct infrared countermeasure (DIRCM) was gradually proposed, which used high-power Xenon lamp or laser as sources of infrared energy. DIRCM has advantageous infrared countermeasure properties, such as the capability of jamming infrared imaging seeker by jamming, dazzling, in-band damaging and out-ofband damaging, etc, the capability of reuse and high jamming efficiency, which makes it suitable for new generation of infrared countermeasure system. The international research on DIRCM systems and technology in recent years was reviewed. And the operational principle, jamming damage mechanism, technology advantage of DIRCM system and the development status abroad were focused. And the research trends of DIRCM system and technology were forecasted in the next years. ©, 2015, Chinese Society of Astronautics. All right reserved.

Hui F.,University of Jinan | Qin F.,Shanghai Electro Mechanical Engineering Institute
Proceedings - 2016 8th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2016 | Year: 2016

Most global navigation satellite system (GNSS) receivers cannot work in high dynamic scenarios because of poor navigation satellite acquisition in these environments. Hence, inertial navigation system (INS) is used to aid the GNSS signal acquisition and improve the acquisition capability of the receivers. In this paper, an ultra-tight integration system using the low-cost IMU is proposed to achieve navigation for high dynamic applications. To verify the effectiveness of the ultra-tight integration, an experiment system is built and a high dynamic scenario is simulated. The results prove that the designed ultra-tight integration system has perfect tracking and navigation performances for high dynamic applications. © 2016 IEEE.

Li X.,Beijing Institute of Technology | Wang X.-P.,Shanghai Electro Mechanical Engineering Institute
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2015

The effect of shape parameter selection on the accuracy of the surrogate model constructed by using the radial basis function (RBF) is discussed, based on which an alternative method for determining the optimal value of the shape parameter is investigated. In this method, the normalized root-mean-square error (NRMSE) of the surrogate model is expressed as a function with respect to the shape parameter. Consequently a minimization optimization problem is constructed, in which the NRMSE is the objective and the shape parameter is the decision variable. Then the optimization is solved to obtain the optimal shape parameter. For a set of given sample points, the RBF surrogate model using this optimal shape parameter is more accurate than those using other shape parameters. Two numerical test examples, a one-dimension problem and a two-dimension problem, show the effectiveness of this method. A tactical missile aerodynamic shape optimization problem is also solved successfully by using this method. ©, 2015, Chinese Institute of Electronics. All right reserved.

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