Modeling a generalized ecological–economic input–output balance with delay

A solution is obtained for a generalized static model of input–output balance with delay with allowance for pollution control, the optimal trajectory being specified by a piecewise-differentiable function over [t ₀, T], and the optimal control being described by a piecewise-continuous function over [t ₀, T]. A solution algorithm is developed and results of computational modeling are presented.     

Modeling and control of the air system of a turbocharged gasoline engine

In order to reduce CO₂ emissions in the automotive industry, there is a trend to decrease the size of the engines and add turbocharging technologies to increase the engine efficiency while keeping performances. In this context, numerous studies have focused on the improvement of turbocharger control strategies. The strategy proposed in this paper is based on constrained motion planning and feedback linearization applied to a simplified model of the system. It takes advantage of the whole system bandwidth and requires a limited calibration effort. Thanks to its structure, it offers an interesting potential for generalization to more complex turbocharging systems. Extensive experimental tests are reported for a four-cylinder gasoline engine.     

软件系统UML建模与其安全建模的集成

安全是现代软件系统不可缺少的一部分,但是,目前的软件系统建模一般都不涉及安全。系统安全策略和安全机制往往是开发人员在系统开发后期对系统的补充和措施的完善。这种不规范的处理为系统后期安全维护及系统之间的集成带来很大的隐患。该文通过学生成绩管理系统来讨论如何扩充UML图素、为系统安全访问控制策略建模,引入视图策略语言(VPL)描述角色与授权之间的关联,实现了软件系统UML建模与系统安全建模的集成。     

电网分析仪监控系统的UML建模

以电网分析仪监控系统为背景,探讨了基于UML的面向对象系统建模方法,并与传统系统建模方法进行了比较,展示了UML在获取系统功能需求、增强系统可视性和可维护性等方面具有的优点。     

Simulation of Diversified Economic Growth

An optimal growth algorithm is developed for a diversified economic growth model with piecewise-linear production functions. Numerical results are presented. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 147–155, September–October 2005.     

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.     

Modeling process-related RBAC models with extended UML activity models

Context

Business processes are an important source for the engineering of customized software systems and are constantly gaining attention in the area of software engineering as well as in the area of information and system security. While the need to integrate processes and role-based access control (RBAC) models has been repeatedly identified in research and practice, standard process modeling languages do not provide corresponding language elements.

Objective

In this paper, we are concerned with the definition of an integrated approach for modeling processes and process-related RBAC models - including roles, role hierarchies, statically and dynamically mutual exclusive tasks, as well as binding of duty constraints on tasks.

Method

We specify a formal metamodel for process-related RBAC models. Based on this formal model, we define a domain-specific extension for a standard modeling language.

Results

Our formal metamodel is generic and can be used to extend arbitrary process modeling languages. To demonstrate our approach, we present a corresponding extension for UML2 activity models. The name of our extension is Business Activities. Moreover, we implemented a library and runtime engine that can manage Business Activity runtime models and enforce the different policies and constraints in a software system.

Conclusion

The definition of process-related RBAC models at the modeling-level is an important prerequisite for the thorough implementation and enforcement of corresponding policies and constraints in a software system. We identified the need for modeling support of process-related RBAC models from our experience in real-world role engineering projects and case studies. The Business Activities approach presented in this paper is successfully applied in role engineering projects.     

Modeling and nonlinear computed torque control of ship-mounted mobile satellite communication system

A mobile satellite communication system (MSCS) is a device installed on a moving carrier for mobile satellite communication. It can eliminate disturbance and maintain continuous satellite communication when the carrier is moving. Because of many advantages of mobile satellite communication, the MSCSs are becoming more and more popular in modern mobile communication. In this paper, a typical ship-mounted MSCS is studied. The dynamic model of the system is derived using the generalized Lagrange method both in the joint space and in the workspace. Based on the dynamic model, a nonlinear computed torque controller with trajectory planning is designed to track an aimed satellite with a satisfied transient response. Simulation results in two different situations are presented to show the tracking performance of the controller.     

机群协同空战中的指控系统建模与分析

为对机群协同空战指挥控制系统性能进行分析,建立了树型机群指挥控制系统组织结构,并提出了性能评价指标。运用随机Petri网技术分别建立了有预警机指挥和无预警机指挥的机群协同空战指挥控制系统模型。仿真分析表明,基于预警机的机群指挥控制系统可减轻作战飞机的任务负担,且能充分发挥机载武器的超视距作战能力;也证明了随机Petri网技术能够分析指挥控制系统的性能缺陷和瓶颈,从而为系统的设计和改进提供有力的支撑,是描述机群协同空战指挥控制系统问题的一种有效方法。     

烘烤控制系统的UML建模与实现

钢包烘烤控制系统多采用可编程逻辑控制器做控制系统.针对钢包烘烤控制系统,以面向对象方法进行分析和建模,以统一建模语言为工具,进行系统功能分析、对象行为分析并建立系统时序图,从而为烘烤控制系统建立模型.经程序验证,在烘烤控制系统中引入面向对象思想,不仅简化了控制系统程序,并且提高了系统的可维护性.     

一类异步网络控制系统的分析与建模

针对具有异步时序和状态反馈的异步网络化控制系统，分析了在短时延单包传输、多包传输、单包传输有数据包丢失、多包传输有数据包丢失和长时延单包传输等不同网络条件下网络化控制系统的特点，在此基础上首次提出了各种不同条件下网络化控制系统的统一建模方法。这种包含系统噪声的离散状态空间模型的建立，为网络化控制系统的准
准确辨识和有效控制奠定了基础。     

光导AGV智能循迹测控系统的建模与仿真

针对光导式差速驱动型自动导引车的循迹控制系统,构建了一个简化的系统数学模型,并在此基础上进行了控制器的设计,然后通过Matlab/Simulink对系统进行了仿真分析。通过仿真比较了状态反馈控制和模糊控制的控制性能,提出了将这两种控制方式结合的复合控制方法,并得到了较好的仿真结果。该仿真系统模拟的参数接近车体的实际数据,对于实际小车的控制具有一定的参考价值,为今后AGV控制系统的设计提供了依据。     

甲醇/水二元间歇精馏塔的建模与先进控制

应用动态物料平衡和相平衡等机理建模法,建立了一套甲醇／水二元间歇精馏塔实验装置的数学模型。以Matlab为平台,开发了该模型计算软件。设计了塔顶甲醇浓度比例积分反馈推断控制、多个温度联合加醛反馈控制、塔顶甲醇浓度反馈增益自调整控制等控制策略。并应用基于状态空间模型的模型预测控制算法,推导了间歇精馏塔多个浓度反馈时的模型预测控制策略。对这些先进控制策略进行了仿真试验研究,仿真结果被用于指导间歇精馏控制实验,获得了满意的控制结果。     

一种新颖的多电平矩阵变换器的建模与仿真

在传统矩阵变换器和多电平逆变器的基础上，提出一种新颖的多电平矩阵变换器，介绍了其拓扑结构和工作原理．多电平矩阵变换器的能量传递，是通过三相输入电压对中点电容充电到一个恒定直流电压而实现的．选择适当的控制算法和电容电压，能在变换器的两侧合成低次谐波含量小且波形近似于正弦的可控输入／输出电压．对多电平矩阵变换器进行建模和仿真，并探讨了其输出能控性．     

多包传输网络控制系统的对象建模

由于将通讯网络的引入,不可避免地引起传输延时。网络传输延时的存在使网络控制系统的分析和设计更加复杂和困难,尤其是多包传输的网络控制系统。在分析网络多包传输原因的基础上,研究了多包传输网络控制系统的对象建模。系统中传感器采用时间驱动的方式,控制器和执行器采用事件驱动的方式。在考虑系统噪声和网络诱导延时大于一个采样周期的情况下,给出了多包传输的网络控制系统模型。此模型可以用来分析系统的性能。     

New strategy of the variable-structure finite control of controlled plants with time lags

A new strategy based on the feed-forward control method is proposed for control with variable structure. The strategy provides finite-length transient processes in a linear system with time delay. The strategy is based on combining closed-loop and programmable control, which is adjusted with reference to an isochrone with the time less than the transition time. Such a strategy provides an opportunity for the time of the transition processes to be minimal among all the possible ones.     

输送系统的UML建模、优化与实现

将面向对象方法引入输送系统的建模和分析过程,采用统一建模语言UML对系统的功能、对象结构、行为和活动以及实现方式等建立了一整套模型。UML模型可以采用面向对象语言快速实现,按照模块化结构,使用PLC编程语言也可实现面向对象编程。采用UML对输送系统进行分析可将系统实现的复杂性降低,有利于系统的分析和设计,系统的优化算法可以在此基础上进一步研究和实现。（以一个工程为实例,说明了相对于传统的顺控方案,以UML模型为基础的输送系统在开发和维护、扩充和代码重用等方面具有显著优势,UML在顺序控制系统中具有广阔的应用和研究前景。）     

一种新型电液控制系统的建模与分析

建立以高速电磁阀为核心部件的新型系统,详细分析系统工作原理,建立系统的数学模型与传递函数,用Matlab绘制伯德图,用来确定系统是否稳定;优化活塞的加速度用以实现液压缸的平稳启动与停止;最后从理论和仿真两方面对系统的误差来源与影响因素进行详细分析,采用预见控制策略以消除系统的跟随误差,研究结果表明,此方法可有效减少系统的误差,增强系统的定位精度.     

弹性机械手臂的建模与控制

１引言目前工业机器人的负载与自重比一般在１：１０到１：３０之间或更小,而人类的负载与自重比通常可以达到１：３,本体过重是实现机械臂高速运动控制的一个障碍．一方面,提高负载与自重比可以满足高速低能耗的需求,同时,也势必会导致本体刚度的下降,从而使机械臂成为具有弹性的结构．机械手臂的高速运动往往会激励起弹性结构的振动,,给运动控制带来许多挑战性的困难．基于刚性动力学的控制策略已无法用于高速高精度的运动控制,需要基于弹性机械臂的动力学设计更为有效的控制算法,这就是弹性臂建模与控制的研究内容．本文中弹性…