A rule-based control method for a multi-loop production system

A multi-loop integrated-circuit production system is difficult to control due to the complex process flow and the dynamic changing environment. The search for the best control strategy is a multi-objective problem subject to a variety of constraints.This paper describes a rule-based decision support system (RBDSS) for finding the best solution for various needs in order to satisfy the user's multiple goals. This method stores coefficients of equations of regression between the performance measure and a set of the control variables, and searches for the best performances on an interactive basis.The performance of RBDSS is compared with that of a non-AI method (CDSS) in the same experimental case.     

A qualitative temporal information system for process control

A general system is presented in this paper which supports the expression of relative temporal knowledge in process control and management. This system allows knowledge of Allen's temporal relations over time elements, which may be both intervals and points. The objectives and characteristics of two major temporal attributes, i.e. ‘transaction time’ and ‘valid time’, are described. A graphical representation for the temporal network is presented, and inference over the network may be made by means of a consistency checker in terms of the graphical representation. An illustrative example of the system as applied to process control and management is provided.     

A spoken dialog system for the Dutch public transport information service

In the Netherlands there is a nationwide premium rate telephone number that can be dialed to obtain information about various forms of public transport. In 1996 this number was called more than twelve million times. Human operators managed to handle only about nine million of these calls. In order to answer more of these calls, a spoken dialog system was developed to automate part of this service. The automation component concerns information about journeys between two train stations.The starting point of our research was an existing German information system. This system was ported to Dutch. A bootstrapping method was used to collect the data, which in turn were used to improve the system itself.     

Necessary conditions for the optimal control of a system with time-varying transport lags

Necessary conditions to be satisfied if the control of a system with time-varying transport lags is to be optimal, are derived. These correspond to the Euler-Lagrange equations, the first corner condition, and the transversality condition of the calculus of variations. The systems considered can be nonlinear, have a multivariable control, and contain a number of different transport lags. The states and controls of the system are assumed to be unbounded.     

A numerical method for network operator for synthesis of a control system with uncertain initial values

The problem of synthesis of a control system in which the control is found as a function of coordinates of the state space is considered. It is shown that the solution of the synthesis problem for one given initial state may not provide conservation of the optimal value of the functional under variation of the initial state. A problem of control synthesis is formulated, in which it is necessary to find an optimal control for initial values belonging to a given region. It is proved that if the region of initial values is discrete and contains a finite number of points, then a solution to this synthesis problem exists. To solve the synthesis problem, a constructive computational method is proposed, based on the network operator. An example of solving an applied control synthesis problem is presented.     

融合惯导与飞控系统信息的飞行大气全参数估计算法

针对嵌入式大气数据系统高空飞行精度低、跨大气层易失效等问题,提出一种融合惯导与飞控系统信息的 飞行大气全参数估计算法.基于飞行器气动模型及动力学方程,建立惯导信息与大气参数之间的函数 关系,进而利用扩展卡尔曼滤波实现大气参数的实时精确估计.仿真结果表明,该方法具有较高的 精度、良好的稳定性和鲁棒性,而且可以提高大气数据系统的测量范围和可靠性,能够适用于全 飞行包线下攻角、侧滑角、真空速的测量.     

A method for grinding removal control of a robot belt grinding system

As a kind of manufacturing system with a flexible grinder, the material removal of a robot belt grinding system is related to a variety of factors, such as workpiece shape, contact force, robot velocity, and belt wear. Some factors of the grinding process are time-variant. Therefore, it is a challenge to control grinding removal precisely for free-formed surfaces. To develop a high-quality robot grinding system, an off-line planning method for the control parameters of the grinding robot based on an adaptive modeling method is proposed in this paper. First, we built an adaptive model based on statistic machine learning. By transferring the old samples into the new samples space formed by the in-situ measurement data, the adaptive model can track the dynamic working conditions more rapidly. Based on the adaptive model the robot control parameters are calculated using the cooperative particle swarm optimization in this paper. The optimization method aims to smoothen the trajectories of the control parameters of the robot and shorten the response time in the transition process. The results of the blade grinding experiments demonstrate that this approach can control the material removal of the grinding system effectively.     

结合LM算法的PID神经网络预测控制系统

针对工业过程中非线性系统的复杂控制和实时性问题,提出1种基于LM算法的PID神经网络预测控制器的设计方法.该方法在原有的神经网络预测控制基础上,引入了1种新的神经网络结构与学习算法来建立预测模型,并针对该模型采用神经网络逆动态控制方法进行滚动优化以实现下一步控制量的优化.仿真结果表明,该方法有结构简单、计算量小、响应速度快等特点.在一定程度上满足复杂工业过程控制中的实时性要求.     

一个用面向对象方法开发应用系统的实例

结合财政业管管理系统具体说明怎样利用面向对象的方法来分析和设计应用系统。简要地描述系统的需求,Ｃｏａｄ和Ｙｏｕｒｄｅｎ的面向对象的分析方法和面向对象的设计方法,用该方法对邮政业务管理系统ＯＯＡ模型的５个层次进行具体分析,给出了一个子系统的ＯＯＡ模型,讨论了ＯＯＤ模型的４个组成部分的设计。     

A hybrid time-delay prediction method for networked control system

This paper presents an Ethernet based hybrid method for predicting random time-delay in the networked control system.First,db3 wavelet is used to decompose and reconstruct time-delay sequence,and the approximation component and detail components of time-delay sequences are fgured out.Next,one step prediction of time-delay is obtained through echo state network(ESN)model and auto-regressive integrated moving average model(ARIMA)according to the diferent characteristics of approximate component and detail components.Then,the fnal predictive value of time-delay is obtained by summation.Meanwhile,the parameters of echo state network is optimized by genetic algorithm.The simulation results indicate that higher accuracy can be achieved through this prediction method.     

面向多级多域信息系统的访问控制方法研究

针对常用的访问控制模型不能很好地解决多级多域信息系统的访问控制问题,分析了多级多域信息系统的结构特征,提出并实现了一种基于安全级别的访问控制模型。实验结果表明,该访问控制模型达到了预定的目标,可以针对多级多域信息系统的各要素分别进行安全级别设定,通过对安全级别的比较进行访问控制。基于安全级别的访问控制模型相对常用的访问控制模型,具有在多级多域信息系统上更容易部署、对权限的变更反应更为迅速,并且能够限制不安全的信息流动等特点。     

二阶系统有限时间控制方法综述

相比于传统且经典的比例–积分–微分控制(PID)控制, 带有指数参数的有限时间控制方法具有更好的控制性能, 因而引起广泛的关注和研究. 本文首先从方法设计和稳定性分析角度, 对现有主流有限时间控制方法进行整理和归纳, 将其分为17种有限时间状态反馈控制方法及6种有限时间输出反馈控制方法. 其次, 以一类具有普遍和基础性的二阶系统为例, 统一变量和参数, 给出了每种控制方法对应的控制器的显式结构. 然后, 通过原理分析和比较分析, 对每种控制方法的优点及不足之处进行了总结, 尤其是给出了终端滑模控制具有“控制奇异与收敛时间矛盾性”的结论, 以及指出了一些方法存在较大保守性的问题. 最后, 通过列表的方式展示了所有有限时间控制方法的优缺点及值得进一步深入研究的课题     

A method for design of a hybrid neuro-fuzzy control system based onbehavior modeling

It is known that control signals from a fuzzy logic controller are determined by a response behavior of a controlled object rather than its analytical models. That implies that the fuzzy controller could yield a similar control result for a set of plants with a similar dynamic behavior. This idea lends to modeling of a plant with unknown structure by defining several types of dynamic behaviors. On the basis of dynamic behavior classification, a new method is presented for the design of a neuro-fuzzy control system in two steps: 1) we model a plant with unknown structure by choosing a set of simplified systems with equivalent behavior as “templates” to optimize their fuzzy controllers off-line; and 2) we use an algorithm for system identification to perceive dynamic behavior and a neural network to adapt fuzzy logic controllers by matching the “templates” online. The main advantage of this method is that convergence problem can be avoided during adaptation process. Finally, the proposed method is used to design neuro-fuzzy controllers for a two-link manipulator     

Improving method for discrete control system with network structure

This paper is dedicated to designing approximate methods of solving discrete optimal control problems with network structure; the methods involve sufficient optimality conditions derived by V.F. Krotov.     

含正反馈振动主动控制系统的混合自适应控制

对于存在结构正反馈的振动主动控制系统,传统的基于有限冲击响应的自适应前馈控制器设计方法难以同时保证控制系统稳定与良好的控制性能.本文在分析正反馈对前馈控制系统影响的基础上,基于无限冲击响应控制器设计模式,提出一种结合前馈自适应控制器和反馈自适应控制器的混合自适应振动主动控制方法.其中前馈自适应控制器采用参考传感器采集到的扰动相关信号作为参考信号,反馈自适应控制器通过构建扰动的估计量作为参考信号,控制器参数更新采用Landau参数递推算法.以一典型的具有固有正反馈性质的机械振动系统为控制对象,给出了该混合自适应控制算法的详细推导过程以及稳定性和收敛性分析过程,得到了算法稳定与收敛的严格正实条件以及相应放松严格正实条件的要求.在此基础上,通过构建实时振动主动控制实验平台,针对多种振动扰动开展对比实验分析.相关实验结果验证了本文提出的混合自适应振动主动控制方法的可行性和有效性.     

A system decomposition method for region tracking control of a non-holonomic mobile robot with dynamic parameter uncertainties

The tracking control problem of non-holonomic mobile robot systems has been extensively investigated in the past decades, however, most of the existing control strategies were developed specifically for the fixed-point tracking. This technical note focuses on the region tracking control for a non-holonomic mobile robot system with parameter uncertainties in the robot dynamics. With the system decomposition and adaptive control method, some restrictions imposed on the angular and linear velocities of the non-holonomic mobile robot in recent literature are removed, enabling to track dynamic trajectories with any values of the angular and line velocities. The proposed adaptive control scheme can simultaneously solve both the regulation and region tracking problems of a non-holonomic mobile robot with one passive wheel and two actuated wheels. By utilizing the designed control laws, the mobile robot system is able to globally reach inside a moving region specified by potential functions whose path can be a circular curve, a straight line, or sinusoidal curve, by using a single adaptive controller. Since the dynamic region can be specified arbitrarily small, the fixed-point tracking can be regarded as a special case of region tracking studied in this paper. Compared with the traditional fixed-point tracking, region tracking has more flexibility and better robustness. Numerical results are presented to show the effectiveness of the designed strategy.