Adaptive switching supervisory control of nonlinear systems with no prior knowledge of noise bounds

The problem of controlling nonlinear noisy systems affected by parametric uncertainties is approached via the introduction of a supervisor which, whenever needed, switches on, in feedback to the plant, a controller selected from a finite set of predesigned controllers. A Lyapunov-based falsification criterion allows one to ensure robust stability in the presence of uncertain constant parameters and exogenous bounded disturbances. Simulations are discussed in order to illustrate the merits of the proposed algorithms.     

Fixed mesh front‐tracking methodology for finite element simulations

A direct front‐tracking method using an Eulerian–Lagrangian formulation is developed in two space dimensions. The front‐tracking method is general in that it can track any type of interface once its local velocity is specified or has been determined by calculation. The method uses marker points to describe the interface position and tracks the interface evolution on a fixed finite‐element mesh, including growth, contraction, splitting and merging. Interfacial conditions are applied directly at the interface position. The method is applied to three scenarios that involve different interface conditions and are based on energy and mass diffusion. The three calculations are for the dendritic solidification of a pure substance, the cellular growth of an alloy, and the Ostwald ripening of silica particles in silicon. Numerical results show that very complicated interface morphologies and topological changes can be simulated properly and efficiently. Copyright © 2004 John Wiley & Sons, Ltd.     

单膛石灰竖窑的改造

我厂竖窑容积为250m^3，设计利用系数为0．85t/(m^3．d)。随烧结产量的不断增加，石灰产量已不能满足烧结生产的需要。为了提高石灰产量，进行了扩容改造，容积由原来250m^3增加到298m^3，并针对目前生产实际提出下一步改造设想。     

制造业跟踪系统解决方案剖析

NetLinx技术的发展，使得跟踪系统发生了划时代的飞跃，在制造业上的应用更加广泛。本文以一间显像管厂为例，详细介绍了跟踪系统在制造业上的应用。     

Position synchronization of multiple motion axes with adaptive coupling control

A new control approach to position synchronization of multiple motion axes is developed, by incorporating cross-coupling technology into adaptive control architecture. The control strategy is to stabilize position tracking of each axis while synchronizing its motion with other axes’ motions so that differential position errors amongst axes converge to zero. The proposed adaptive controller and parameter estimator employ coupling control by feeding back position errors and differential position errors, and have been realized to guarantee asymptotic convergence to zero of both position and synchronization errors. Simulations conducted on a multi-axis motion control system demonstrate the effectiveness of the method.     

机械CAD课程教学改革探讨

文章分析了机械CAD技术的特点以及国内CAD教学的现状,提出了机械CAD教学改革的方法,并从教学体系、教学方法、考试方式等方面进行了探讨.     

20T/H工业锅炉主汽压回路参数寻优自适应PID控制

本文给出了一个自适应PID调节器应用于工业锅炉燃烧系统控制的实例,为克服自适应 控制中所遇到的实际问题,采用了监控级专家控制.实际运行表明,该系统优于常规PID调节器.     

新型保温材料—炭化稻壳在连铸生产中的应用效果

对新型保温材料──炭化稻壳的理化指标及其保温性能进行了阐述。在连铸生产中采用炭化稻壳做保温剂可取得显著的经济效益，是理想的保温材料。     

有环境约束时完成一族跟踪任务的力控制

本文为工业机器人提出了一种极点配置控制法，这种控制方法的优点有：一是它的积分作用消除了机器人的微小扰动和稳态误差；二是能任意设置系统的极点，因此能保证闭环系统的稳定性和规定状态变量的暂态响应；三是加入了加速度反馈，抑制了由电枢电感所引起的机械手的振动，最后，给出了ＰＵＭＡ５６２机器人的计算机仿真和实验结果验证了此控制法的有效性。     

红外目标精跟踪方法的研究

本文提出了一种直接把红外前视传感器的输出作为测量值来跟踪红外目标的扩展型卡尔曼滤波跟踪算法。在滤波处理时,设置可变的测量矩阵,其目的在于提高运算速度和抑制噪声干扰。通过具体的实例,对所提跟踪算法的特点和有效性进行了细致的分析。