微创介入手术主动导管的矩阵式驱动系统的设计

根据徽创介入手术主动导管尺寸微小、空间有限不能容纳过多导线的结构特点,提出了一种矩阵式驱动控制系统,使用最少的导线完成对多个SMA驱动器的控制。利用单片机输出的脉宽调制(PWM)信号对脉冲电流进行调节和多个驱动器之间的相互配合作用,实现主动导管的导向动作。

Robust Stability Analysis of Edge Polynomials with Variable Length

The concept of edge polynomials with variable length is introduced. Stability of such polynomials is analyzed. Under the condition that one extreme of the edge is stable, the stability radius of edge polynomials with variable length is characterized in terms of the real spectral radius of the matrix H -1 ( f 0) H (g) , where both H (f 0) and H (g) are Hurwitz like matrices. Based on this result, stability radius of control systems with interval type plants and first order controllers are determined.

Robust H∞ output feedback control for a class of uncertain Lur＇e systems with time-delays

In this work, the analysis of robust stability and design of robust H∞ output feedback controllers for a class of Lur'e systems with both time-delays and parameter uncertainties were studied. A robust H∞ output feedback controller based on Linear Matrix Inequalities (LMIs) was developed to guarantee the robust stability and H∞ performance of the resultant closed-loop system. The presented design approach is based on the application of descriptor model transformation and Park's inequality for the bounding of cross terms and is expected to be less conservative compared to reported design methods. Finally, illustrative examples are advanced to demonstrate the superiority of the obtained method.

H_∞ Control Based on LMIs for a Class of Time-delay Switched Systems

The problem of H∞ stability analysis and control synthesis of switched systems with delayed states under arb/trary switchirg laws is considered. By means of Lyapunov function and linear matrix inequality tools, sufficient ctmdition of H∞ stability is presented in terms of linear matrix inequalities. Furthermore, the robust H∞ control synthesis via state feedback and output feedack is studied. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.

Improved H_∞ control for networked control systems with network-induced delay and packet dropout

The H_∞ performance analysis and controller design for linear networked control systems(NCSs) are presented.The NCSs are considered a linear continuous system with time-varying interval input delay by assuming that the sensor is time-driven and the logic Zero-order-holder(ZOH) and controller are event-driven.Based on this model,the delay interval is divided into two equal subintervals for H_∞ performance analysis.An improved H_∞ stabilization condition is obtained in linear matrix inequalities(LMIs) framework by adequately considering the information about the bounds of the input delay to construct novel Lyapunov–Krasovskii functionals(LKFs).For the purpose of reducing the conservatism of the proposed results,the bounds of the LKFs differential cross terms are properly estimated without introducing any slack matrix variables.Moreover,the H_∞ controller is reasonably designed to guarantee the robust asymptotic stability for the linear NCSs with an H_∞ performance level γ.Numerical simulation examples are included to validate the reduced conservatism and effectiveness of our proposed method.

Robust guaranteed cost observer design for linear uncertain jump systems with state delays

This paper deals with the robust guaranteed cost observer with guaranteed cost performance for a class of linear uncertain jump systems with state delay.The transition of the jumping parameters in systems is governed by a finite-state Markov process.Based on the stability theory in stochastic differential equations,a sufficient condition on the existence of the proposed robust guaranteed cost observer is derived.Robust guaranteed cost observers are designed in terms of a set of linear coupled matrix inequalities.A convex optimization problem with LMI constraints is formulated to design the suboptimal guaranteed cost observers.