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In this paper, a robust adaptive higher order sliding mode attitude control scheme is proposed for near space hypersonic glide vehicles. This problem can be viewed as the finite time stabilization of a higher order input-output dynamic system with bounded uncertainties. The control scheme developed is based on geometric homogeneity and dual layer adaptive sliding mode control. Simulation results show the effectiveness of the proposed controller to track the guidance instruction for the 6-DOF model of hypersonic reentry vehicles.

In this paper, an alternative scheme to achieve output tracking for a class of uncertain systems which is designed using back-stepping control and sliding mode control (SMC) can provide exact tracking even in the presence of matched and unmatched disturbances. The newly proposed method is based on a nonlinear disturbance observer (NDOB) which can estimate the unmatched disturbance. Simulation verify the validity of the proposed approach.

The vertical tail of an aircraft produces a large radar signature and the requirement for stealth in new military aircraft necessitates the design of tailless aircraft. Without the vertical tail results in lateral-directional response characteristics which are a great deal different from those of conventional aircraft. In this paper, a robust controller designed for the tailless aircraft is presented. The controller's basic structure consists of an inner-loop DI controller wrapped around an outer-loop robust µ-synthesis controller. The inner-loop controller equalizes the tailless aircraft dynamics across the flight envelope, and the outer-loop controller addresses the issues of stability, performance, and robustness to tailless aircraft uncertainties.

Online identification and real-time aircraft model updating allows the adoption of more intelligent control methods. An identification algorithm called Fourier Transform Regression that uses the recursive Fourier transform and least-square methods is employed to identify the aerodynamic and control derivatives online. The main contribution of this paper is to adopt a vector of forgetting factors for tracking the time-varying parameters in system dynamics. Simulation results indicate that the proposed scheme works well.

A step-index polymer optical fibre (SI POF) containing rhodamine B in poly (methyl methacrylate) (PMMA) has been fabricated by a perform technique. The rhodamine B content of the doped SI POF is 5 ppm-wt. The spectra of the doped SI POF with different fibre lengths were measured. Amplified spontaneous emission (ASE) at 609 nm of an SI POF in length 40 cm has been observed at ambient temperature by end-pumping with a Nd:YAG laser operated at 532 nm. The threshold of absorbed pump power for the onset of ASE is about 0.003 mJ.

A guidance law derived by variable structure theory, to enable the imposition of a predetermined terminal engagement geometry to a maneuvering target, is presented in this paper. The interceptor assumed to have no knowledge about the maneuver type of the target is executing. The guidance law has the ability to simultaneously achieve design specifications on the miss distance and the final interceptor-target relative orientation. The latter specification may be used to enhance the performance of warhead, whose effectiveness is influenced by the terminal encounter geometry between interceptor and target. The guidance law is parameterized with the terminal conditions of miss distance and terminal encounter angle. The performance of the proposed guidance law is demonstrated by the simulation results.

The optical transition probability of Nd3+ (0.5 mol%) doped lanthanum-modified lead zirconate titanate (PLZT) is investigated. The absolute intensities of its forced electric dipole transitions between 400 nm and 1000 nm were measured, from which we obtain three phenomenological parameters, Ω2 = 0.787×10−20 cm2, Ω4 = 1.182×10−20 cm2, and Ω6 = 1.042×10−20 cm2, according to the Judd–Ofelt theory. The radiation lifetime (346.9 μs) of the 4F3/2 metastable state, the stimulated emission cross-section σij (2.49×10−21 cm2, 6.51×10−21 cm2, 2.17×10−21 cm2) and the fluorescence branch ratios are calculated. We also measured the fluorescence lifetime (155.84 μs) and calculated the quantum efficiency (46.1%). The analysis reveals that Nd3+-doped PLZT, based on its large electro-optical effect, has potential applications in active optical devices.

We investigate the polarized emission behaviour of an Eu3+ doped azo-polymer waveguide. Affected by the azobenzene groups in the photoinduced orientation process by the 532 nm linearly polarized laser, the ligands were realigned orderly perpendicular to the direction of the orientation direction. This leads to the polarized absorption and emission of the waveguide in the orientation direction. By an m-line apparatus based on the prism coupling technique, two guided propagation modes were observed in the waveguide, and the refractive index at 650 nm in TE polarizations is 1.7505.

We present the diffraction patterns observed in the gradient-index (GRIN) lens sensor experiment. Then the diffraction pattern of radial GRIN lens is explored by using matrix optics. The theoretical results agree with the experimental results of 27.9-mm-long GRIN lens with 2-mm diameter diffraction patterns.

Localization is an essential problem for application of Wireless Sensor Network (WSN). We introduce a mobile robot to localize the sensor nodes in cooperative way. Specifically, we consider sensors would provide range measurements between themselves. The localization strategy was set to be a mixed form of centralized and distributed manner considering the character of robot and WSN. The algorithm can efficiently fuse multiple measurements of the system to form conservative covariance estimates and avoid over-confident problem properly. The algorithm was described in a Bayes framework and proved to be efficient in simulation result.

Sporting goods industry is one of the most internationally competitive sports industries in China. More and more enterprises begin to make use of network marketing so as to tackle the competition and satisfy the demands of consumers. Pricing strategy has become the key to the success in network marketing. Sporting goods' consumers choose online shopping because of conveniently gaining a large number of product information. According to the characteristics of network marketing, this paper analyzes low-price, customization pricing, usage pricing, discount pricing, auction pricing and prestige pricing strategies. Sporting goods enterprises should choose the sound pricing strategies in accordance with the different characteristics of products and the status of the online market.

With the advances in the network technology and the development of the network market, more and more sports enterprises compete with each other through network advertising. In this paper, the basic forms of network advertising have been demonstrated. And its fundamental values include brand promotion, website promotion, sales promotion, online survey, customer relations and information issue. Based on the comparative analysis on network advertising of Li Ning, Nike, Adidas and other well-known sports enterprises, it is aimed to present the prospects of online advertising of China's sports enterprises.

As an effective access to sources of information, the education in the 21st century is characterized by the extensive application of information technology. With a lot of advantages, IT application to P.E. teaching reform has become one of the most important topics. In this paper, based on theoretical and practical analysis, it suggests that at present stage, problems are quite apparent in applying IT to P.E. such as outdated ideas about education, shortage of fund and high-quality teachers, neglect of the dominant position of students and so on. Concerning these problems, corresponding countermeasures are put forward, including changing ideas about education, increasing investment, providing technical support, strengthening training of the teacher and establishing the informationized teaching mode of “student-centered, teacher-led”.

This paper presents a nonlinear disturbance observer-based finite time convergent second order sliding mode control scheme for a tailless aircraft with uncertain parameters. Command angles and angular rate commands are robustly tracked in outer and inner loops correspondingly via finite time convergent second order sliding mode controllers. Nonlinear disturbance observer is employed to retain overall high accuracy of the closed-loop tracking. An optimal control allocation algorithm is employed using nominal mathematical model of an aircraft. The control approach is applied to the innovative control effectors (ICE) fighter aircraft. Computer simulations demonstrate high accuracy tracking performance.

This paper proposes a new three-dimensional (3D) guidance law for the impact angles control, using the variable structure control theory. In order to study the problem of the precision guidance, the three-dimensional terminal motion of air-crafts is divided into the motion in the vertical plane and the bank plane. Then the decoupling control of the guidance law is designed independently. After the linear optimal guidance laws are designed with terminal multi-constraint conditions of miss-distance, impact trajectory inclination angle and impact trajectory rotation angle, we let the linear optimal model act as the referenced model and take the linear optimal input as the reality system's referenced input. According the model matching condition, the guidance parameters are updated by variable structure laws to ensure high precision in the impact angle conditions. Some simulations of the characteristic trajectory are performed. The simulation's results show the variable structure guidance law based on adaptive model-following control is not only satisfied with the need of precision guidance and impact angular constraints, but also have excellent trajectory in terminal guidance.

RoboCup is an increasingly developed international high-tech based match to promote AI, robotics, and related fields. As an item of the whole project, the small-size group is a hardware based match. This paper discusses the robots system implement of such a match. At first, we introduce the RoboCup match and the research of our country. Then the small-size group rules are given in brief. After this, two main architectures of the implement are analyzed: the global vision system and the distributed vision system. At last, based upon above analysis,we bring forward our implement: an omni-direction based global vision system, and indicate the future work.

The Robot World Cup is the largest mobile robot event and the most important international conference on AI and robotics at present. RoboCup is an attempt to promote AI and robotics research by providing a common task for evaluation of various theories, algorithms, and agent architectures. This paper studies the theoretical and technical issues of the application of the expert system for robot planning theory to RoboCup. This paper gives a primary introduction of the expert system and the robot planning, the content includes the theory of the robot planning based on expert system and the framework of the system that based on the theory. Finally, its application of the framework to RoboCup and how machine learning can be integrated in the system are also studied in this paper.

As a standard research platform of artificial intelligence and robotics, RoboCup is gathering more and more attention. Because in the match, the environment is dynamically changing, the method of machine learning is widely used. An important problem is how to reduce the complex environment in learning, so that the number of states is decreased. The paper briefly introduces Soccer Server. Then several methods of constructing the state space are analyzed. A method of reduction of the state space is described. The method divides the environment around the client into some regions which are not equal in size. The state space is constructed with these regions.

Imaging properties of two-dimensional photonic crystal slab lens consisting of a triangular lattice of ring-shaped air holes in a high-refraction-index dielectric medium have been studied. The results calculated by the plane wave expansion method （PWE） and the finite-difference time-domain method （FDTD） show that the effective index n=-1 can be realized in this structure. A perfect image can be obtained by increasing the inner radius of ring-shaped holes from 0 to 0.13a with the outer radius 0.4a at the normalized frequency 0.3（a/λ）. Based on the result of normalized frequency with effective refraction index -1 versus inner radius of ring-shaped holes we theoretically analyzed the effects of structure parameters to equifrequency contours of respective normalized frequency and imaging properties.