Nonlinear control for a class of hydraulic servo system

The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening,friction,etc. Aside from the nonlinear nature of hydraulic dynamics,hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues,a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well,and all signals in the closed-loop system remain bounded. Moreover,a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers,this paper's robust controller based on backstepping recursive design method is easier to design,and is more suitable for implementation.     

Robust adaptive controller design for a class of nonlinear systems with unknown high frequency gains

INTRODUCTIONMany researchers have devoted their energy to the development of nonlinear system with unknown control directions during the past few years. The class of nonlinear system has been developed greatly since Mudgett and Morse (1985) relaxed the assumption that the unknown multiplicative terms are not only sign-invariant but also have known signs. A method called correction vector approach was proposed in (Lozano et al., 1990) and has been applied to design adaptive controller of …     

Mixed Gl_2/GH_2 multi-channel multi-objective control synthesis for discrete time systems

INTRODUCTION In the past two decades, a large number ostrategies for control systems analysis and synthesis such as H2, H∞, l1 and μ-synthesis had beendeveloped. In H∞design, all disturbances arelumped into a single norm rather than boundedseparately by the size of each disturbance as ||d||2=||d1||2 … ||dm||2. This certainly leads to some conservatism (D’Andrea, 1999). In contrast, theμ-synthesis technique overcomes the conservatismby introducing structured uncertainty block…     

Interval standard neural network models for nonlinear systems

INTRODUCTION Neural networks have been successfully em- ployed for controlling nonlinear systems since the 1990’s (Narendra and Parthasarathy 1990; Hunt et al., 1992; Suykens et al., 1996). In these nonlinear control systems, neural networks have been used either for modelling the system to be controlled, or for design- ing a controller, or both. Recently, the robustness issue has been an important focus of research in neuro-control circles (Suykens et al., 1996; Wams et al., 1999; Aya…     

基于混沌的图像版权通知兼版权保护水印算法

提出了一种嵌入多功能图像双水印算法．利用三维复杂Liu混沌系统产生的X、Y序列控制可见水印嵌入系数的选择,在图像的空域嵌入可见水印,以实现版权通知功能．采用广义Amold映射置乱不可见水印的嵌入位置,增加不可见水印抵抗非法提取的安全性．对提出的算法进行实验仿真,验证了算法的有效性．     

邓小平稳定周边的战略思想探析

邓小平外交思想是邓小平理论的重要组成部分,而邓小平稳定周边的战略思想是邓小平外交思想关键的一环。邓小平从战略的高度出发,主张睦邻外交,稳定与周边大国的关系,创造性地提出搁置争议、共同开发的战略举措。邓小平稳定周边的战略思想,不仅深刻地影响了邓小平时期的中国外交,而且也对后邓小平时期的中国外交产生了持续而深远地影响。     

Robust predictive control of uncertain intergrating linear systems with input constraints

This paper presents a two-stage robust model predictive control (RMPC) algorithm named as IRMPC for uncertain linear integrating plants described by a state-space model with input constraints. The global convergence of the resulted closed loop system is guaranteed under mild assumption. The simulation example shows its validity and better performance than conventional Min-Max RMPC strategies. Project supported by Education Bureau of Zhejiang Province (No. 20010539), China     

区间离散广义系统的鲁棒镇定

研究了区间离散广义系统的状态反馈鲁棒镇定问题.首先,用区间矩阵的一种等价描述形式,将所讨论的区间离散广义系统变换成对应的矩阵范数有界的参数不确定性离散广义系统.其次,在此基础上,基于矩阵不等式,得到了区间离散广义系统可由状态反馈鲁棒镇定的一个充分条件,并利用矩阵不等式的解给出了控制器的设计方法.     

A robust tolerance design method based on process capability

This paper presents a method for robust tolerance design in terms of Process Capability Indices (PCI). The component tolerance and the suitable manufacturing processes can be selected based on the real manufacturing context. The robustness of design feasibility under the effect of uncertainties is also discussed. A comparison between the results obtained by the proposed model and other methods indicates that robust and reliable tolerance can be obtained.     

含时滞不确定线性系统的输出鲁棒镇定

研究了含时滞的不确定系统的输出反馈鲁棒镇定问题，该系统同时含有时变状态时滞和时变控制时滞，所构造的控制器增益矩阵包含在两个Hamiltonina矩阵中。所给镇定的充分条件易于检测，控制器有易于设计的特点。