The results of simulation show that the soft sensor based on the proposed method has high precision and is suitable for time - varying system with samples which distribution is not uniform . 5 工业数据仿真结果表浙江大学博士学位论文明，该方法在线建立的软测量模型精度高，很适合慢时变对象、且训练样本分布不均匀情况下的软测量建模。
The following are the contributions of this paper : robotic manipulator is a time - varied system . so it ' s difficult to achieve good convergence effect and highly convergent speed if the constant iterative learning operators are used 本文的创新点和主要工作在于： ?机械手是一个时变的系统，如果采用固定的迭代学习算子，很难达到很好的收敛效果和较快的收敛速度。
It is necessary to study the reliability of the structure during the construction because the structure is a time - varying system and the variable loads are random processes about time with particular characteristics different with the use period 由于施工过程中，结构是一个时变结构，结构的抗力是一个随机过程，荷载也具有与使用期不同的特点，所以有必要研究施工期间结构的可靠度。
In this paper the effect of the track twist irregularity on the train derailment safety is analysed on the basis of dynamic analysis of train - tangent - track space - coupling time - varying system , and the limitation of the track twist irregularity in the line maintenance principle is assessed 应用列车-轨道空间耦合时变系统振动分析理论，分析了轨道三角坑对列车脱轨安全性的影响，并就现行铁路线路维修规则中对轨道三角坑的限值进行了评估。
Abstract : in this paper the effect of the track twist irregularity on the train derailment safety is analysed on the basis of dynamic analysis of train - tangent - track space - coupling time - varying system , and the limitation of the track twist irregularity in the line maintenance principle is assessed 文摘:应用列车-轨道空间耦合时变系统振动分析理论，分析了轨道三角坑对列车脱轨安全性的影响，并就现行铁路线路维修规则中对轨道三角坑的限值进行了评估。
Abstract : iterative learning control is an effective approach to the control of processes that are repetitive in nature . in this paper , an open - closed - loop pi - type iterative learning control scheme for the precise tracking control of a class of discrete nonlinear time - varying systems over a finite time interval is presented . the scheme updates control input with tracking errors of both current and last iterations simultaneously . sufficient and necessary conditions which guarantee the convergence of the scheme are given and then proved with inductive method . finally , the conditions are verified with simulation results 文摘:对于具有重复运动性质的对象，迭代学习控制是一种有效的控制方法.针对一类离散非线性时变系统在有限时域上的精确轨迹跟踪问题，提出了一种开闭环pi型迭代学习控制律.这种迭代律同时利用系统当前的跟踪误差和前次迭代控制的跟踪误差修正控制作用.给出了所提出的学习控制律收敛的充分必要条件，并采用归纳法进行了证明.最后用仿真结果对收敛条件进行了验证
Stability for a class of nonlinear feedback system is studied in this paper . thus some sufficient and necessary conditions are given . these results are suitable for both time - invariant and time - varying systems . as an application , the general time - varying lur e problem is studied too . then the time - varying circle criterion in the siso case is given . at the same time , in the mimo case , a stability criterion is given , which doesn t need the decoupling conditions -稳定性问题，给出了其稳性分析准则和一些必要条件，这些结果适用于时不变与时变系统。其次，利用已有的结果，研究了非线性环节具有扇区特性的稳定性问题。在单输入单输出siso的情况下，给出了时变系统的圆判据。
There are lots of non - linear systems in the nature . because classical and morden control methods have common limitation : mathematical model of the plant has to be known in advance . but in fact many plants are intricate uncentaintied and time - varying . in addition , they also are non - linear . though there are methods of system identification in control theories , the identification theories and ways of non - linear and time - varying system are not mature and systematic . it is very difficult to carry out effective real - time control . the neural networks can approximate random non - linear relations and study by itself , and it provides new thoughts and new ways for solving these problems 由于经典和现代控制方法存在一个共同的局限性：就是要求预先知道被控对象的数学模型，但实际上许多对象具有复杂的不确定性和时变性；此外还具有复杂的非线性。虽然在控制理论中有系统辨识的手段，但是对于非线性时变系统尚无成熟的和系统的辨识理论与方法，要实行有效的实时控制就很难了。人工神经元网络有表示任意非线性关系和自学习等能力，给解决这些问题提供了新思想和新方法。
The reference signal and the disturbance signal are controlled , which can achieve optimal effect in the meantime , applying adaptive lms algorithm based on variable step and variable region to variable frequency speed regulation system , the initial convergence rate , tricking ability of time - varying system and stable precision are best in the meantime 利用变论域变步长的lms自适应滤波算法，使自适应逆控制的异步电机变频调速系统及其逆系统辨识的初始收敛速度、时变系统跟踪能力及稳态精度3个指标同时达到最优。
In the real industry process , pid control is still one of the important ways . so how to find a simple and effective way to achieve adjustment is meaningful . to those nonlinearity and time - varying system , it is significant to achieve pid parameters auto - tuning 在实际的工业控制中, pid控制依然是最主要的一种控制方式,所以如何简单、有效的实现pid参数的整定有着重要的工业意义;对于工业过程中常出现的非线性、时变的系统来讲,如何实现pid参数的自整定显得犹为重要。
