非方广义系统的未知输入有限时间观测器设计

研究了含未知输入的非方广义系统的有限时间输入解耦观测器设计问题,在一定条件下基于非方广义系统的结构特征,引入一个输入-状态对的非奇异转换,把含未知输入的非方广义系统等价地转化为输入已知的正常状态空间系统．用传统的设计正常状态空间系统观测器的方法去构造含未知输入的非方广义系统的未知输入观测器,并给出了观测器存在的充分条件,由此得出了有限时间观测器的设计步骤．     

Sliding mode control and a variable structure system observer as a dual problem for systems with non-linear uncertainties

Sliding mode control is described for continuous-time systems with uncertain nonlinear elements, in which the euclidean norm of the unknown element is bounded by a known value. For a case of complete state information, we first consider a sliding mode controller consisting of three parts: a linear state feedback control, an equivalent input and a min-max control. It is then shown that the present attractiveness condition is simpler than that for a case without using the concept of equivalent input. We next derive a variable structure system (VSS) observer as a completely dual form to the sliding mode controller. The attractiveness condition is also simpler than that for a case an equivalent term is not used, but a more severe assumption is required to solve such a VSS observer. Finally, we discuss a case of incomplete state information by applying the VSS observer.     

匹配条件不满足时线性系统未知输入观测器设计

针对一类不满足观测器匹配条件的线性系统,讨论了未知输入观测器设计方法.首先,为了突破观测器匹配条件的限制,提出了一种与未知输入相对阶无关的辅助输出构造方法.然后,把未知输入看作系统状态的一部分,将原系统转化为一个不含未知输入的增维线性描述系统.针对这样的系统转化,对一系列等价前提条件进行了详细的讨论.之后,针对该增维线性描述系统,构造Luenberger观测器来估计原系统的状态和未知输入.同时,借助于高阶滑模微分器,来估计辅助输出中的未知信号.最后,对一个单连杆柔性机械手模型进行了数值仿真,仿真结果表明了方法的有效性.     

广义系统区间观测器设计

对于不确定或者未知输入系统, 常规鲁棒观测器设计对系统和干扰有较多限制条件. 区间观测器对系统具有宽松的前提条件, 且对干扰只要求有界, 因而区间观测器更具有广泛性. 针对离散和连续的广义未知输入系统, 研究区间观测器的设计问题, 通过对离散系统和连续系统进行不同的变换, 将系统转化为易于求取区间观测器系数矩阵的形式; 然后基于相同的参数求取方式, 给出广义系统区间观测器的设计方法. 仿真结果表明了所提出方法的有效性和正确性.

     

基于有限时间观测器的离散系统混沌同步

本文基于驱动–响应模型针对一类离散时间混沌系统提出了一种基于有限时间观测器的同步方法. 首先, 将混沌系统写成具有未知输入的线性系统形式. 随后, 给出了观测器匹配条件和强可观条件. 在观测器匹配条件的 假设下, 通过适当的状态变换, 给出了具有降维形式的有限时间观测器设计框架使得该观测器不再受到未知输入的 影响. 然后, 证明了强可观条件结合观测器匹配条件可以保证一个有限时间观测器的存在, 该观测器可以使得响应 系统达到对驱动系统的精确同步, 且达到同步所需要的时间可以任意设定, 不受观测器系统矩阵极点配置和初值条 件的影响. 最后, 给出了两个混沌系统的例子验证了所提方法的有效性.     

不可测前件变量模糊H∞观测器研究及在GMAW系统的应用

基于前件变量未知的T-S模糊系统设计一类模糊观测器.将模糊系统转化为广义系统的形式,提出一种广义系统的观测器设计方法,消除了控制输入对观测误差方程的影响.针对测量端含有扰动的模糊系统,通过拉格朗目中值定理,将模糊观测器转化为一组线性矩阵不等式的求解问题,并将这种观测器的设计方法应用到熔化极气体保护焊系统,快速有效地实现了对弧长的观测.最后通过仿真分析验证了所提出的观测器设计方法的有效性.     

自适应广义滑模观测器之状态估计和故障重构

针对一类同时具有执行机构故障和输出扰动的不确定性系统,提出了一种自适应广义滑模观测器,实现系统状态的估计和执行机构故障的重构.首先,进行系统变换及状态增广构成一类奇异系统,使得执行机构故障和输出扰动解耦,且输出扰动成为增广系统的状态之一;随后,受未知输入观测器和滑模观测器的启发,设计了一种广义滑模观测器,放宽了传统方法对输出维数的严格约束,并通过融入自适应技术放宽了对故障和不确定性上界已知的要求;最后,利用等效误差注入的思想实现故障重构.针对可重复使用运载器再入段进行的仿真实例,验证了所提方法的有效性.     

Non-linear observer design by transformation into a generalized observer canonical form

An observer design method for a certain class of non-linear single output systems is introduced. The characteristic feature of this method consists of the fact that it does not require any linearization in the way that the given non-linear system is approximated by a linear one. The present paper deals with the derivation of a transformation of the considered non-linear system into a generalized observer canonical form (GOCF) which enables a systematic observer design similar to the linear one based on the well-known linear observer canonical form. To assign conditions for its existence, the transformation into the GOCF is carried out in two steps via a generalized observability canonical form (GOBCF). In contrast to previous forms used for linear systems, the two non-linear canonical forms presented here also depend on the time derivatives of the input variables. This means that the resulting observer has to be supplied, not only with the input and output variables of the given system, but also with derivatives of the input variables. However, a final example shows that it is possible to eliminate those derivatives in special cases.