Kalman filter for controlled hybrid systems

The linear partially observed discrete-continuous (hybrid) stochastic controllable system described by differential equations with measures is considered. The optimal filtering equations in the form of generalized Kalman filter are obtained in the case of non-anticipating control. This result could be a theoretical basis for the optimal control in stochastic hybrid systems with incomplete information.     

一种数字图像盲增强的新算法

给出一种数字图像盲增强的新算法. 其中源数字图像及其灰度级未知, 已知的仅仅是被噪声污染了的图像. 该算法首先估计密度函数, 然后估计图像的灰度级, 最后去噪声重建图像, 达到图像增强的目的. 仿真例子说明了该算法的有效性.     

无源性控制在有源电力滤波器中的应用

线路或负载参数未知可能会导致有源滤波器系统失稳，为解决系统的稳定性问题，将无源性控制应用于有源电力滤波器来保证系统的稳定性。将有源滤波器和非线性负载视为一个整体，对负载进行诺顿等效，把负载电压和电源电流作为状态变量，把补偿电流作为控制变量，建立系统在dp轴上的模型。获得系统的控制律也就获得了补偿电流的给定值，验证系统满足无源性条件之后，再利用无源性控制方法获得系统的控制律。虽然算法在理论上比较复杂，但是实现上相当简单。在仿真中，对比了容性负载，感性负载以及变动负载情况下的控制效果，仿真结果表明算法具有很好的鲁棒性，并能很好的保证系统的稳定性。     

一类不确定离散时间系统的鲁棒故障诊断滤波器优化设计方法

研究线性不确定离散时间系统的鲁棒故障诊断滤波器设计问题。基于新提出的性能指标函数，将不确定离散时间系统的故障诊断漶波器设计问题归结为肌优化问题，并通过选择适当的后滤波器和观测器增益矩阵，得到未知输入和模型不确定性鲁棒性的最优解。     

基于小波分析的交通流量预测方法

为了更加准确地预测动态变化的交通流量，根据交通流量的特点提出了在小波分析的基础上利用离散Kalman滤波进行预测的方法。这种方法可用于动态数据预测的各个领域，如网络流量的预测、经济信息的预测以及其它非线性系统的预测。实验表明，采用这种方法可以有效地减小数据预测的误差。     

An LMI approach to design robust fault detection filter for uncertain LTI systems

In this paper, the robust fault detection filter design problem for uncertain linear time-invariant (LTI) systems with both unknown inputs and modelling errors is studied. The basic idea of our study is to use an optimal residual generator (assuming no modelling errors) as the reference residual model of the robust fault detection filter design for uncertain LTI systems with modelling errors and, based on it, to formulate the robust fault detection filter design as an H_∞ model-matching problem. By using some recent results of H_∞ optimization, a solution of the optimization problem is then presented via a linear matrix inequality (LMI) formulation. The main results include the development of an optimal reference residual model, the formulation of robust fault detection filter design problem, the derivation of a sufficient condition for the existence of a robust fault detection filter and a construction of it based on the LMI solution parameters, the determination of adaptive threshold for fault detection. An illustrative design example is employed to demonstrate the effectiveness of the proposed approach.     

Pole placement with sensitivity function shaping using 2nd order digital notch filters

This technical note deals with the design of robust digital controllers using pole placement with sensitivity shaping by means of the use of digital notch (band-stop) filters. The use of this type of filters drastically simplifies the effective shaping of the sensitivity functions and the resulting procedure competes with the procedure based on the use of Q-parameterization combined with convex optimization (Automatica 35 (1999) 1111). The feasibility of the technique is illustrated by its application to the control of a very flexible arm.     

On the H fixed-lag smoothing: how to exploit the information preview

The problem of the continuous-time H^∞ fixed-lag smoothing over the infinite horizon is studied. The first solution to the problem is derived in terms of one algebraic Riccati equation of the same dimension as in the filtering case and the mechanism by which the performance improvements with respect to the H^∞ filtering occur is clarified. It is shown that the H^∞ smoother exploits the information preview in an “H² manner”.     

深度图像的平滑

由于受到各种干扰，结构光方法获取的深度图像重建结果中包含大量的毛刺，本文将平面图像平滑的方法拓展到深度图像领域，通过分析噪声模型，我们利用中值滤波器和高斯滤波器对深度图像进行三维平滑。结合去噪电路，取得了满意的重建效果。     

基于自然语言处理的网页过滤方法研究

www上的信息极大丰富，搜索引擎存在精确度低的问题。为准确地从搜索到的网页中提取有用信息，发展一个自动的过滤器已成为当务之急。本文提出的基于自然语言处理的网页过滤方法，从语法、语义和语境三个方面上分析网页的自然语言。实验表明，该方法在一定程度上提高了搜索引擎的精确度。