A robust APD synchronization scheme and its application to secure communication

This paper proposes a robust active-passive decomposition (APD) synchronization scheme. Compared with the original APD scheme, the robust APD scheme can effectively deal with the uncertainty in the master. Further, this scheme can also be applied to secure communication, where the hidden message can be recovered by the concept of equivalent control. Simulation results of Lorenz system verify the effectiveness of the proposed scheme.     

通用组合式教育机器人动力学模型及其快速仿真算法(英文)

为实现具有开放结构的组合式教育机器人自动建模与动态仿真,建立了教育机器人的动力学模型及其仿真算法.首先,将教育机器人抽象为多体系统,利用牛顿一欧拉法建立其通用的动力学模型,并结合教育机器人的结构特点,以构件绑定方法对机器人模型进行了简化.其次,基于稀疏矩阵计算技术,对计算机仿真中常用的增广动力学求解算法和直接投影修正算法进行改进,以此作为教育机器人的仿真算法,提高仿真速度和精度.最后,通过一个算例验证了模型和改进算法的有效性.该研究为实现教育机器人仿真平台奠定了动力学基础.     

一类非线性扰动广义时滞系统的鲁棒保性能控制

研究了不确定非线性结构扰动的广义系统的鲁棒控制和保性能控制问题.为了分别设计系统的鲁捧控制器和保性能控制器,应用线性矩阵不等式方法.分别给出了系统的鲁棒控制器和保性能控制器存在的充分条件.并在这些条件可解时,分别给出了鲁棒控制器和保性能控制器的表达式.     

一类具有时滞的不确定系统的鲁棒稳定性

本文利用Alekseev公式和Bellman－Gronuwall不等式,讨论了一类具有时滞的不确定中立型微分系统的鲁棒稳定性问题,给出了不确定系统在具有时滞的反馈控制下是渐近稳定的充分条件。     

Unknown input observer for linear non-minimum phase systems

An unknown input observer is to estimate the system state of a dynamic system subject to unknown input excitations. In this note, by assuming that at each time instant, the unknown input can be approximated by a polynomial over a local time interval, a finite-time observer is proposed to achieve approximate joint state and input estimation. Both the obtained state and input estimates are moving averages of the present and past output signals. The advantage of the proposed design is that it can be applied to non-minimum phase systems or systems with non-unity relative degree. Notice that most previous unknown input observer designs require the system to be minimum-phase and relative degree one.     

Adaptive robust approximate constraint-following control for mechanical systems

We formulate control problems of mechanical systems as constraint following. The system contains uncertainty which is (possibly fast) time-varying. It is unknown but bounded. The bound is, however, unknown. The objective is to design control which renders approximate constraint following. Adaptive laws are constructed. The controls are then based on the adaptive parameters. We are able to demonstrate guaranteed system performance, regardless of the uncertainty.     

试论改革、发展、稳定与构建和谐社会的有机性

改革、发展,稳定与构建和谐社会相互联系,密不可分。正确认识和处理改革发展稳定的关系,注意把握好改革措施出台的时机和节奏,把改革的力度、发展的速度和社会可承受的程度统一起来,在社会稳定中推进改革发展,通过改革发展促进社会稳定,和谐社会的构建才能实现。而在构建社会主义和谐社会的过程中,则必将有助于更好地认识和处理改革,发展,稳定的关系。     

论我国现代化进程中的中产阶层与政治稳定

西方发达国家和亚非拉后发展中国家的现代化进程表明，国家实现现代化的过程往往是伴随中产阶层崛起的过程，中产阶层的不断扩大是国家维护社会政治稳定的重要保障。从我国现实国情出发，中产阶层尚处于发育的初级阶段，借鉴国外经验，我国现阶段应大力培育形成中产阶层的合适土壤。     

Nonlinear control for a class of hydraulic servo system

INTRODUCTION Electro hydraulic servo systems (EHSS) havebeen used in industry in a wide number of applica-tions due to their small size-to-power ratio and theability to apply very large force and torque. How-ever, the dynamics of hydraulic systems are highlynonlinear (Merritt, 1967), the system may be sub-jected to non-smooth and discontinuous nonlin-earities due to control input saturation, directionalchange of valve opening, friction, and valve overlap.Aside from the nonlinear na…     

社会分层视角下的社会稳定

贫富差距不断扩大使社会不公平问题加剧，各个阶层之间出现了矛盾和冲突，影响了我国社会的和谐与稳定。市场经济本身并不能消除各阶层之间不断扩大的差距，如果不加控制，差距只会越来越大，因此政府必须进行适当的干预和调节，通过建立良性的社会分层结构来促进各阶层之间互惠互利、和谐相处，实现社会的长期稳定。