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Chen Z.,Huazhong University of Science and Technology | Luo S.,Huazhong University of Science and Technology | Xie T.,Huazhong University of Science and Technology | Liu J.,Huazhong University of Science and Technology | And 2 more authors.
Infrared Physics and Technology | Year: 2014

Compared to other targets, it is more difficult to detect infrared small targets due to several aspects such as the low signal to noise ratio, low contrast, small size, the lack of shape and texture information of the targets, especially under complex background. In this paper, a novel infrared small target detection method based on peer group filter (PGF), bi-dimensional empirical mode decomposition (BEMD) and local inverse entropy (LIE) is proposed to overcome these difficulties. The PGF is implemented to remove the noise and improve the signal-to-noise ratio of the initial image. Our proposed BEMD algorithm is able to estimate the background effectively and get the target image by removing the background from the original image and segmenting the Intrinsic Mode Functions (IMFs) making use of the local inverse entropy. Experimental results demonstrate that the novel method can extract the small targets validly and accurately. © 2014 Elsevier B.V. All rights reserved. Source


Han H.L.,National Key Laboratory of Science and Technology on Aerospace Intelligence Control | Han H.L.,China Aerospace Science and Technology Corporation
Applied Mechanics and Materials | Year: 2014

To solve the problem of the incompatible and interoperable in complex system configured by different buses or transducers, the paper introduced the IEEE1451 standard protocol, the transducer electric data sheet specified in the standard was analyzed in detail. On the basis, a smart sensor module was designed based on FPGA, TEDS specified in IEEE1451.2 were designed, data of transducers were filled in and downloaded in graphic and programmable VB language. Adopting intelligent TEDS in IEEE1451.2 standard improves the system performance, cost-effective and versatility, making the complex system be developed more easily, data processing simple. © (2014) Trans Tech Publications, Switzerland. Source


Ren Y.,Beihang University | Ren Y.,Inner Mongolia University of Science and Technology | Liu Z.,Beihang University | Liu X.,China Aerospace Science and Technology Corporation | And 2 more authors.
Mathematical Problems in Engineering | Year: 2013

Aiming at the uncertainties including parameter variations and external disturbances in optoelectronic tracking system, a discrete-time global sliding mode controller (DGSMC) is proposed. By the design of nonlinear switching function, the initial state of control system is set on the switching surface. An adaptive discrete-time reaching law is introduced to suppress the high-frequency chattering at control input, and a linear extrapolation method is employed to estimate the unknown uncertainties and commands. The global reachability for sliding mode and the chattering-free property are proven by means of mathematical derivation. Numerical simulation presents that the proposed DGSMC scheme not only ensures strong robustness against system uncertainties and small tracking error, but also suppresses the high-frequency chattering at control input effectively, compared with the SMC scheme using conventional discrete-time reaching law. © 2013 Yan Ren et al. Source


Lin Z.,Zhejiang University | Lin Z.,University of Newcastle | Hou J.,China Aerospace Science and Technology Corporation | Hou J.,National Key Laboratory of Science and Technology on Aerospace Intelligence Control | And 2 more authors.
Automatica | Year: 2015

This brief presents a new distributed scheme to solve the consensus problem for a group of agents if neither their absolute states nor inter-agent relative states are available. The new scheme considers a random partition of agents into two subgroups at each step and then uses the relative group representative state as feedback information for the consensus purpose. It is then shown that almost sure consensus can be achieved under the proposed scheme in both discrete time and continuous time. For the discrete time case, almost sure consensus is achieved if and only if the weighting parameter for state update is greater than one. For the continuous time case, almost sure consensus is realized when the weighting parameter is positive. Moreover, it is shown that if a uniform probability is considered for group selection, then the group of agents can reach average consensus in mean. © 2014 Elsevier. Ltd All rights reserved. Source


Xiong S.,Beihang University | Wang W.,Beihang University | Liu X.,China Aerospace Science and Technology Corporation | Liu X.,National Key Laboratory of Science and Technology on Aerospace Intelligence Control | And 2 more authors.
ISA Transactions | Year: 2014

This study explores the guidance law against maneuvering targets with the intercept angle constraint. The limitation of the traditional guidance law, which simply treats the unknown target acceleration as zero, has been analyzed. To reduce this limitation, a linear extended state observer is constructed to estimate the acceleration of the maneuvering target to enhance the tracking performance of the desired intercept angle. Furthermore, a nonsingular terminal sliding mode control scheme is adopted to design the sliding surface, which is able to avoid the singularity in the terminal phase of guidance. Simulation results have demonstrated that the proposed guidance law outperforms the traditional guidance law in the sense that more accurate intercept angle can be achieved. © 2014 ISA. Source

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