Robust stabilization of uncertain 2-D discrete-time delayed systems using sliding mode control

This paper aims to solve the problem of sliding mode control for an uncertain two-dimensional (2-D) systems with states having time-varying delays. The uncertainties in the system dynamics are constituted of mismatched uncertain parameters and the unknown nonlinear bounded function. The proposed problem utilizes the model transformation approach. By segregating the proper Lyapunov–Krasovskii functional in concert with the improved version of Wirtinger-based summation inequality, sufficient solvability conditions for the existence of linear switching surfaces have been put forward, which ensure the asymptotical stability of the reduced-order equivalent sliding mode dynamics. Then, we solve the controller synthesis problem by extending the recently proposed reaching law to 2-D systems, whose proportional part is appropriately scaled by the factor that does not depend on some constant terms but rather on current switching surface’s value, which in turn ensures the faster convergence and better robustness against uncertainties. Finally, the proposed results have been validated through an implementation to a suitable physical system.     

Chattering-free full-order recursive sliding mode control for finite-time attitude synchronization of rigid spacecraft

This paper investigates a quaternion-based finite-time cooperative attitude synchronization and tracking of multiple rigid spacecraft with a virtual leader subject to bounded external disturbances. Firstly, the communication network between followers is assumed to be an undirected graph and every follower can get a direct access to the virtual leader, by using two neighborhood attitude error signals, a novel chattering-free recursive full-order sliding mode control algorithm is proposed such that all follower spacecraft synchronize to the virtual leader in finite time. In the proposed algorithm, the sliding mode surface is constructed by two layers of sliding mode surfaces, which are called as the outer and the inner sliding mode surfaces. To achieve finite-time performance of sliding mode dynamics, the outer sliding mode surface is designed as a terminal sliding mode manifold, and the inner one is designed as a fast nonsingular terminal sliding mode manifold, respectively. Then, to reduce the heavy communication burden, a distributed recursive full-order sliding mode control law is designed by introducing a distributed finite-time sliding mode estimator such that only a subset of the group members has access to the virtual leader. Finally, a numerical example is illustrated to demonstrate the validity of the proposed results.     

Integrated guidance and control with partial state constraints and actuator faults

In this paper, a novel adaptive integrated guidance and control (IGC) scheme is proposed for skid-to-turn (STT) missile with partial state constraints and actuator faults. Considering the strict-feedback form of the IGC model, the dynamic surface control (DSC) approach is adopted to design the IGC scheme. To prevent the attack angle, sideslip angle and velocity deflection angle from violating the constraints, the barrier Lyapunov function (BLF) and modified saturation function are employed in the IGC design procedure. Moreover, an auxiliary system is constructed to remove the adverse effects that caused by the modified saturation function. The adaptive laws are constructed to estimate the actuation effectiveness of actuators and the upper bounds of lumped uncertainties in the IGC model. It is theoretically shown that all signals in the closed-loop system are bounded while the state constraints are not violated in presence of actuator faults and uncertainties. Numerical simulation results are presented to verify the effectiveness and robustness of the proposed IGC scheme.     

Adaptive neural design frame for uncertain stochastic nonlinear non-lower triangular pure-feedback systems with input constraint

This paper dedicates to dealing with the adaptive neural design problem for uncertain stochastic nonlinear systems with non-lower triangular pure-feedback form and input constraint. On the basis of the mean-value theorem, the pure-feedback structure is first transformed into the desired affine structure, and then the well-known backstepping technology is applied to construct the actual input signal of the controller. Although the considered system has a fairly complex structure, a new adaptive neural tracking controller design frame is established via the flexible application of radial basis function (RBF) neural networks’ (NNs’) structural characteristics. The proposed design frame guarantees the control objective of this paper can be achieved. Finally, a simulation example is given to further illustrate the availability of the proposed control scheme.     

军队院校数字图书馆标准规范体系架构

数字图书馆要避免成为信息孤岛,就要加强标准规范的制定与实施.文章在归纳我军内部已有的标准规范体系基础上,依据一定的目的与原则,并充分吸收国内外已有的标准规范来架构我军院校数字图书馆的标准规范体系,最后指出军队院校数字图书馆标准规范体系的建设需掌握的两大策略.     

高速智能布线器—Specctra

Specctra自动布线器采用强大的Shape-based算法实现交互式、智能化布线。Specctra可完成大型高密度电路设计,大大提高布线速度、缩短设计时间。     

关于坚持和完善民主集中制的几个问题

民主集中制是我们党和国家的根本组织制度和领导制度,是保证领导干部正确行使职权的制度保证。针对市场经济条件下出现的新情况新问题,要求领导干部继承和发扬我们党坚持民主集中制的优良传统,进一步提高贯彻执行民主集中制的自觉性。特别要紧密联系当前工作实际,努力推进选人用人民主化和决策民主化。     

2000年以来民国文献影印出版状况研究

从民国文献影印出版机构、出版内容以及文献类型几个方面,概述2000年以来民国文献出版的现状,总结其出版特点,并指出民国文献影印出版过程中存在的出版机构分布过于集中、出版选题相似或雷同,出版形式规模过大,出版文献类型不平衡,以及索引编制重视程度不够,电子版本开发缺失等问题。同时提出了进一步开展民国文献影印出版的建议:加强地方出版机构对民国文献的整理与出版;研发影印版民国文献目录检索系统,避免重复出版;建立民国文献资源调配与出版共享机制;采用整套和分卷出版相结合的形式,解决图书馆资源建设难题;鼓励电子版本的制作和共享,加速出版物的数字化进程。     

我国数字出版人才现状与需求分析

利用网络问卷的方式进行采样分析.在281份样本基础上,从数字出版人才的来源、规模、类型、年龄、学历、专业等多个方面进行分析,并在此基础上提出我国数字出版人才培养对策.