Adaptive Sliding Mode Control for Re-entry Attitude of Near Space Hypersonic Vehicle Based on Backstepping Design

Combining sliding mode control method with radial basis function neural network(RBFNN), this paper proposes a robust adaptive control scheme based on backstepping design for re-entry attitude tracking control of near space hypersonic vehicle(NSHV) in the presence of parameter variations and external disturbances. In the attitude angle loop, a robust adaptive virtual control law is designed by using the adaptive method to estimate the unknown upper bound of the compound uncertainties. In the angular velocity loop, an adaptive sliding mode control law is designed to suppress the effect of parameter variations and external disturbances. The main benefit of the sliding mode control is robustness to parameter variations and external disturbances. To further improve the control performance, RBFNNs are introduced to approximate the compound uncertainties in the attitude angle loop and angular velocity loop, respectively. Based on Lyapunov stability theory, the tracking errors are shown to be asymptotically stable. Simulation results show that the proposed control system attains a satisfied control performance and is robust against parameter variations and external disturbances.

Sliding mode control for an aerodynamic missile based on backstepping design

In order to solve the mismatched uncertainties of a class of nonlinearsystems, a control method of sliding mode control (SMC) based on the backstepping design isproposed. It introduces SMC in to the last step of backstepping design to modify the backsteppingalgorithm. This combination not only enables the generalization of the backstepping design to beapplied to more general nonlinear systems, but also makes the SMC method become effective in solvingthe mismatched uncertainties. The SMC based on the backstepping design is applied to the flightcontrol system design of an aerodynamic missile. The control system is researched throughsimulation. The simulation results show the effectiveness of the proposed control method.

Concept Design,Modeling and Station-keeping Attitude Control of an Earth Observation Platform

The stratosphere airship provides a unique and promising platform for earth observation. Researches on the project design and control scheme for earth observation platforms are still rarely documented. Nonlinear dynamics, model uncertainties, and external disturbances contribute to the difficulty in maneuvering the stratosphere airship. A key technical challenge for the earth observation platform is station keeping, or the ability to remain fixed over a geo-location. This paper investigates the conceptual design, modeling and station-keeping attitude control of the near-space earth observation platform. A conceptual design of the earth observation platform is presented. The dynamics model of the platform is derived from the Newton-Euler formulation, and the station-keeping control system of the platform is formulated. The station-keeping attitude control approach for the platform is proposed. The multi-input multi-output nonlinear control system is decoupled into three single-input single-output linear subsystems via feedback linearization, the attitude controller design is carried out on the new linear systems using terminal sliding mode control, and the global stability of the closed-loop system is proven by using the Lyapunov theorem. The performance of the designed control system is simulated by using the variable step Runge-Kutta integrator. Simulation results show that the control system tracks the commanded attitude with an error of zero, which verify the effectiveness and robustness of the designed control system in the presence of parametric uncertainties. The near-space earth observation platform has several advantages over satellites, such as high resolution, fast to deploy, and convenient to retrieve, and the proposed control scheme provides an effective approach for station-keeping attitude control of the earth observation platform.

动态教学模式(Dynamic Design Teaching Model)——建筑学环境设计专业教学改革探索

近年来随着中国经济的快速发展和人民生活水平的不断提高,社会各阶层人士对人居环境表现出广泛热情和更高要求,社会对环境设计专业人才的需求日益增强,环境设计专业已成为艺术类院校招生的热门专业,并广受关注。随着环境设计对象和设计类型的增加与丰富,人居环境的范畴不断拓展,加之新时代大学生身心呈现新的特点变化,高校环境设计专业的传统教学模式,已无法完全满足社会需求、适应学科专业人才培养目标,迎合青年学生学习兴趣和方式,传统教学模式亟待改革创新。本文旨在通过分析环境设计专业理论与实践教学环节传统教学方法存在的弊端,提出一种创新的教改思路——动态教学模式(Dynamic Design Teaching Model),探讨此教学模式的可实施性,试图为地方高校建筑学环境设计专业和设计学相关学科提供教学新思路。

Design of Multi-mode Mobile Terminal Chips

Based on the analysis of B3G evolution, the base-band processing chips for mobile terminals are introduced. Key technologies for multi-mode mobile terminal base-band chips are discussed. Terminal technologies are thought to be the key of B3G, and terminal base-band chips are regarded as the core of terminal technologies. Therefore, a unified wireless development platform is required for the R&D of multi-mode mobile terminal base-band processing chips.

Paralleled DC-DC Power Converters Sliding Mode Control with Dual Stages Design

This paper proposes the new cascaded series parallel design for improved dynamic performance of DC-DC buck boost converters by a new Sliding Mode Control (SMC) method. The converter is controlled using Sliding Mode Control method that utilizes the converter’s duty ratio to determine the skidding surface. System modeling and simulation results are presented. The results also showed an improved overall performance over typical PID controller, and there was no overshoot or settling time, tracking the desired output nicely. Improved converter performance and robustness were expected.

Innovative Mode and Application of Flipped Classroom in City Design Course

The city planning quick topic design is a part of the city design course in many urban planning colleges.It can help stimulate the students’off-handed creativity and image expression ability.So it is necessary to explore the teaching mode which can adapt to it and stimulate students’learning enthusiasm and creative ability.In the context of promoting the"classroom revolution"of higher education in China,the flipped classroom has received widespread attention in the higher education community.Based on this,after three years of teaching practice,the author adaptively adjusted and innovatively modified the basic model of flip classroom in the quick topic design teaching of the city design course,and has found a variant model applicable to this course,namely OCTIAS(objective-case exploration-trial and error-instructional video-activities-summary and promotion).Firstly,insert two sections before the video learning,including"case travel exploration"and"trial and error(in order to accumulate beneficial failures)".Secondly,in the classroom activities,sort out the problems reflected by the students,and organize the students to make self-evaluation,mutual evaluation and revise the trial and error plan before the class.Finally,think about the problems that may occur in the cities in the future and their spatial organization responses.The practice showed that compared with the traditional teaching mode,the OCTIAS model could make the city design course more interesting,and help the students to improve in the solidity of theoretical knowledge learning,the flexibility of practical operation,the initiative to think about realistic problems,and the ability of critical thinking and expression.

Structural design and modal behaviors analysis of a new swept baffled inflatable wing

Inflatable wing has significant application value in the design of loitering munitions because of its advantages such as lightweight and foldability.However,due to the flexible characteristics,aeroelastic behaviors of inflatable wings such as flutter are nonnegligible in flight.By designing a certain angle between the inflatable beam and the wing span,the structural dynamic and even the aeroelastic performance of the inflatable wing can be effectively improved.Based on the analysis of the mechanical and geometric characteristics of the inflatable structure,a new inflatable wing with sweep arranged inflatable beams is proposed,and the main design variables and methods are analyzed.For purpose of investigating the aeroelastic performance of the swept baffled inflatable wing,the modal behaviors by considering the wet mode are studied.In consideration of the deficiencies of the traditional wet modal analysis method,by introducing the influence on the additional stiffness of flow field,an added massstiffness method is proposed in this paper,and the advantages are verified by ground vibration experiments.On this basis,the effects of baffles sweep angle,pressure,and boundary conditions on the modal parameters and aeroelastic performance of inflatable wing are analyzed.The results show that the aeroelastic performance of the inflatable wing can be designed by changing the baffles sweep angle,which is enlightened for the aeroelastic tailoring design on inflatable wings.

Prediction of column failure modes based on artificial neural network

To implement the performance-based seismic design of engineered structures,the failure modes of members must be classified.The classification method of column failure modes is analyzed using data from the Pacific Earthquake Engineering Research Center(PEER).The main factors affecting failure modes of columns include the hoop ratios,longitudinal reinforcement ratios,ratios of transverse reinforcement spacing to section depth,aspect ratios,axial compression ratios,and flexure-shear ratios.This study proposes a data-driven prediction model based on an artificial neural network(ANN)to identify the column failure modes.In this study,111 groups of data are used,out of which 89 are used as training data and 22 are used as test data,and the ANN prediction model of failure modes is developed.The results show that the proposed method based on ANN is superior to traditional methods in identifying the column failure modes.

Modular flexible“Tetris”microsatellite platform based on sandwich assembly mode

In this paper,a flexible modular“Tetris”microsatellite platform is studied to implement the rapid integration and assembly of microsatellites.The proposed microsatellite platform is fulfilled based on a sandwich assembly mode which consists of the isomorphic module structure and the standard mechanical-electric-data-thermal interfaces.The advantages of the sandwich assembly mode include flexible reconfiguration and efficient assembly.The prototype of the sandwich assembly mode is built for verifying the performance and the feasibility of the proposed mechanical-electric-data-thermal interfaces.Finally,an assembly case is accomplished to demonstrate the validity and advantages of the proposed“Tetris”microsatellite platform.

Landscape Design Mode Based on the Integration of Ecology, Production and Life

Taking landscape design of Suburban Park in Yulin City for example, this paper applied the design thoughts of integrating multiple planning, defining concepts and objectives, specified the design strategies of restoring ecology, improving life and promoting production, and disclosed the landscape design mode based on the integration of ecology, production and life in which ecological landscapes, productive landscapes and living landscapes promote and coexist harmoniously with each other.

Discussion on the Informative Teaching Mode of the Elective Course of Packaging Design for Medical Plant Products

This article believes that in the context of the"Made in China 2025"development strategy,the teaching of the elective course of Packaging Design for Medicinal Plant Products is facing reform.It proposes to conduct research in five aspects:students'survey,classroom teaching reform,practical teaching reform,application of information technology and evaluation of teaching reform effects.Questionnaire survey,case analysis,group discussion and student test are used to discuss the informative teaching model,aiming to train application-oriented information-oriented professional senior talents in the direction of medicinal plant product packaging design.

Shape Anisotropy and Resonance Mode Guided Reliable Interconnect Design for In-plane Magnetic Logic

Dipole coupled nanomagnets controlled by the static Zeeman field can form various magnetic logic interconnects.However, the corner wire interconnect is often unreliable and error-prone at room temperature. In this study, we address this problem by making it into a reliable type with trapezoid-shaped nanomagnets, the shape anisotropy of which helps to offer the robustness. The building method of the proposed corner wire interconnect is discussed,and both its static and dynamic magnetization properties are investigated. Static micromagnetic simulation demonstrates that it can work correctly and reliably. Dynamic response results are reached by imposing an ac microwave field on the proposed corner wire. It is found that strong ferromagnetic resonance absorption appears at a low frequency. With the help of a very small ac field with the peak resonance frequency, the required static Zeeman field to switch the corner wire is significantly decreased by ~21 m T. This novel interconnect would pave the way for the realization of reliable and low power nanomagnetic logic circuits.

The Effective Teaching Design of Primary School English Classroom Based on BOPPPS Teaching Mode

Teachers are crucial to the success of primary school English teaching.As to BOPPPS teaching mode,it is well-known for its effectiveness of teaching and values the enhancement of teachers’teaching ability.In order to integrate BOPPPS mode into primary school English teaching,there is a need to elaborate bridge-in,and clarify the learning objective.Then based on the pre-assessment,teachers are supposed to know students’prior knowledge,interest,and ability.For the participatory learning,which emphasizes both teacher-student interaction and student-student interaction,the activities should be diversified and interesting.In addition,during the stages of post-assessment and summary,teachers should pay close attention to learning outcome,offer feedback timely,and guide students to make reflection.

Reconstruction and paradigm of the thinking mode of environmental art design

Environmental art design covers almost all contemporary art and design, and is a comprehensive system of art and design.Therefore, the image of thinking dominated, integrated design thinking is the main feature of the environmental design. At present, the specialtyof environmental art design offered by universities in our country starts relatively late compared with foreign countries. The basic course and thespecialized course, the theory class and the practice class have the serious disconnection phenomenon. In addition, there are some problems in theconstruction of teaching staff. The teaching experience, academic level and professional level of teachers need to be further improved. Therefore,environmental art design specialty teaching reform must proceed from the actual environmental art design, strengthen the application of practiceteaching, which will be closely connected with the market, the theoretical knowledge learned in the classroom through the practice has beenconsolidated, cultivate creative design thinking of designer.

The difference of Teaching Mode of Graphic Design Major in Chinese and American Universities

This article is based on personal visits to Louisiana State University in the United States.It analyzes and introduces the hotspots of curriculum design,training methods,learning environment,professional ability and quality training of graphic design majors in American public comprehensive universities.Analyze the teaching concepts and methods that are inspiring for the relevant design courses for our country from a personal perspective,and gain insights into the deep-seated problems in the cultivation of design innovation capabilities in China and the United States,in order to arouse everyone’s reflection and further develop our country’s design educational reform ideas.

Discussion on the Teaching Mode Innovation of Environmental Art Design Major based on OBE Concept

This paper explores the innovative ways of teaching mode of environmental art design major under the concept of OBE.Through theoretical elaboration,combined with the understanding of literature and practical work experience,it innovates from three aspects of teaching concept,teaching system and training objectives,and establishes an innovative teaching system.

Discussion on teaching mode of traditional color design

The origin and development of design industry is inseparable from color education. Although the color teaching in higher design education in China has also played a great role, with the development of the times, the drawbacks of the traditional color design teaching mode have emerged. This paper discusses this problem.

Software for Acoustic Design

We present the СATEС software, which implements the solution to the problems of computational acoustics. The software is based on the use of the superelement method and finite element modeling algorithms, in-cluding hydrodynamic noise. The paper presents the main possibilities of software for solving acoustic design problems. .