PCI总线研究及多轴控制器设计

论文从总体方案选择、多轴控制器设计、PCI接口设计和系统软件设计四个方面,详细论述了基于PCI总线的多轴控制器设计的关键技术和特点。为了解决多轴控制器相互交互的问题,多轴控制器在主机通讯接口设计上引入了PCI总线。本文首先论述了多轴控制器的硬件和PCI接口设计。最后详细介绍了基于PCI总线的多轴控制器的驱动程序设计。     

多形态标志设计理念与方法探析

多形态标志设计近年来逐渐被人们所关注和应用,成为未来标志设计的一大发展趋势。文章通过对多形态标志设计理念的探析以及对多形态设计方法的分类和概括,尝试从理论角度和案例实践角度总结多形态标志设计出现的必要性和必然性,为多形态标志设计的未来发展提供力所能及的探索和思考。     

DMSA在时序签核中的应用

在芯片的设计过程中,静态时序分析(Static Timing Analysis,STA)无疑是整个设计中最重要的一环。如今纳米级工艺下的芯片设计往往属于多工艺角多模式(MultiCorner-MultiMode,MCMM)物理设计,工艺角和工作模式的特定组合称之为场景,多场景的物理设计会给芯片带来更加稳定的性能,但也会使静态时序分析变得更为复杂。介绍了分布式多场景时序分析(Distribute Multi_Scenario Analysis,DMSA)技术在多工艺角多模式物理设计中的应用。经过基于Smic 90 nm工艺的多场景数字芯片Cxdp13设计实践分析表明,在一定硬件条件支撑下,分布式多场景时序分析技术在多工艺角多模式的物理设计中可以达到快速时序签核的目的。     

数字集成电路多周期路径的设计实现方法

多周期路径是将复杂电路运算拆分在多个时钟周期完成,从而提高电路总体运行频率的一种设计方法,是数字电路中广泛使用的一种设计手段。实践中多周期路径的设计、约束与实现经常误用导致设计迭代和反复。文中结合在研项目,对多周期路径的产生机理进行了系统的分析,针对设计中常见的问题展开分析,提出了一种多周期路径的设计实现和施加约束的方法。实践结果表明,采用文中提供的方法可以有效避免多周期路径的误用,减少设计迭代,提高设计效率。     

数字集成电路多周期路径的设计实现方法

多周期路径是将复杂电路运算拆分在多个时钟周期完成,从而提高电路总体运行频率的一种设计方法,是数字电路中广泛使用的一种设计手段。实践中多周期路径的设计、约束与实现经常误用导致设计迭代和反复。本论文结合在研项目,对多周期路径的产生机理进行了系统的分析,针对设计中常见的问题展开分析,提出了一种多周期路径的设计实现和施加约束的方法。实践结果表明,采用本文提供的方法可以有效避免多周期路径的误用,减少设计迭代,提高设计效率。     

卫星有效载荷的多目标多学科设计优化研究

在卫星有效载荷系统研究中,实施多目标多学科优化的可行性设计。首先,分析了开展卫星有效载荷多学科设计优化的关键技术。建立了包含天线、转发器、数据传输、可靠性、成本和质量的多学科分析模型。然后,应用多目标遗传算法对某卫星有效载荷的可靠性和成本进行多目标设计优化,获得最优解集。最后,运用多学科协同优化结合遗传算法进行可靠性单目标设计优化。研究结果表明:有效载荷的多目标多学科设计优化全面考虑了多个学科之间的关系,设计人员可按需选择其满意的优化结果,大幅提高设计效率;协同优化方法有助于实现学科自治、并行设计,提高设计的灵活性和缩短设计周期。     

CSCW环境下协同设计的多版本问题及其管理策略

该文从协同设计的特点出发，分析了协同设计中多版本的形成过程和特点。协同设计中的多版本可以从时间和空间两个角度来分类，其中，空间多版本又可分为平行多版本和视图多版本。文章概括了ＣＳＣＷ环境下协同设计的版本管理内容，并提出了一些版本管理的方法。     

面向装配的多Agent协同设计研究

分析了面向装配设计（ＤＦＡ）技术发展和存在的问题,提出了ＤＦＡ中多Ａｇｅｎｔ协同设计研究的必要性。对设计Ａｇｅｎｔ的概念、结构及设计过程进行了描述和研究,并在此基础上对多Ａｇｅｎｔ协同设计过程和表示做了进一步的研究。最后,对面向ＤＦＡ的多Ａｇｅｎｔ协同原型设计系统进行了设计。     

Inventor基于多实体的Top-Down设计

对Inventor基于多实体的Top-Down设计进行了介绍,描述了基于多实体的Top-Down设计的主要步骤,分析了设计方法的优点。     

自顶向下设计的多骨架建模方法

为了解决传统骨架模型设计参数传递路径单一的局限性,并且降低上下层设计单元之间的耦合性,提出自顶向下设计的多骨架建模方法.首先结合不同类型的设计参数定义位置骨架、发布骨架和设计骨架的概念,并阐述多骨架的特点;然后提出自顶向下分层递阶的多骨架建模方法,通过多骨架建模对设计参数进行分类管理和分层控制;最后阐述多骨架建模过程中设计参数传递方式和传递结构的优化,有利于参数的受控发布和设计单元的重用.对某气象卫星进行骨架建模分析的实验结果表明,该方法是可行和有效的.     

From nonlinear to Hamiltonian via feedback

Mechanical control systems are an especially interesting and important class of nonlinear control systems. They possess a rich mathematical structure and yet, physical considerations are extremely important for the solution of a large class of control problems. We broaden the applicability of design methodologies developed for mechanical control systems by rendering nonlinear control systems, mechanical by a proper choice of feedback. In particular, we characterize which control systems can be transformed to Hamiltonian control systems by a feedback transformation.     

代理控制方法UML建模

本文提出一种新的控制方式——代理控制．在这一方式中，算法成为网络中可移动、可重用的控制实体．代理控制实现了用户按需控制和本地简单与远程复杂控制模式．在本文中，我们对按需控制这一模式进行UML建模，由于UML在模型代理方面的局限性，我们提出虚类图扩展UML表示法．最后我们给出这一模式实现的部分代码．     

A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins

This study aims to develop a waypoint-tracking control system for a biomimetic underwater vehicle (BUV). The BUV is propelled by wide paired pectoral foils, and each pectoral foil is driven by three independent fin rays. To simplify the control strategy, the maximum flapping amplitude of the pectoral fin is used to control the forward velocity, and a turning factor is defined for the manoeuvre control. Several swimming experiments are carried out to investigate the influence of the control parameters on the swimming performance of the prototype. Based on the results of the swimming experiments, a waypoint-tracking control system is proposed, which contains two layers: the velocity control layer and the heading angle control layer. A subdivision control method is adopted by the velocity control layer to get the maximum flapping amplitude. The fuzzy control method is employed by the heading angle control layer to obtain the turning factor for steering motion. Several waypoint-tracking experiments are carried out to verify effectiveness of the control system. The results show that the prototype can automatically reach the target area with the designed control system, even though the waypoints are arranged or randomly given.     

Compensation of plant variations in optimal control systems

Control of a linear plant, with bounded control input, may be implemented by constructing a control law generator which produces the optimal control as a function of the state variables. If the plant parameters differ from their nominal values, then maintaining optimal control by changing the control law generator is inconvenient since the control law is usually nonlinear. It is shown that in certain cases optimal control can be maintained without changing the control law generator. This is accomplished by using a linear transformation of state variables as the input to the control law generator. The variations of the plant are compensated for by changing the linear transformation. The conditions under which this is possible are established in this paper. The advantage of this system is that a change in a linear function is easier to implement than a change in a nonlinear function. It is shown how this system can be incorporated into an adaptive system which compensates for plant variations.     

仿生机器鱼运动控制算法研究

footnotesize A practical motion control strategy for a radio-controlled, 4-link and free-swimming biomimetic robot fish is presented. Based on control performance of the fish the fish's motion control task is decomposed into on-line speed control and orientation control. The speed control algorithm is implemented by using piecewise control, and orientation control is realized by fuzzy logic. Combining with step control and fuzzy control, a point-to-point (PTP) control algorithm is proposed and applied to the closed-loop experimental system that uses a vision-based position sensing subsystem to provide feedback. Experiments confirm the reliability and effectiveness of the presented algorithms.     

Unified design of time-varying gain type access control and integral type servo control by means of nonstationary optimal control method

Servo control is one of the most important control techniques for motion control of mechanical structures. In order to suppress the stationary error between a reference trajectory and a servo system response, servo controllers often include the integral characteristic. For example, linear quadratic integral (LQI) optimal control is one of the standard selections for designing servo control systems. Nonstationary optimal regulator (NOR) is another motion control method, which produces superior vibrationless trajectories for the positioning control problems of vibration systems. This study discusses a unified design method of the time-varying gain type access control similar to NOR and the integral type servo control similar to LQI control by means of a frequency-shaped time-varying criterion function. This method realizes two high performance control modes and the smooth switching of the modes by the optimization of the single criterion function. The effectiveness of this method is verified by numerical calculations and experiments.     

新型Buck-Boost矩阵变换器的双闭环控制策略

为了克服传统矩阵变换器电压传输比低的缺陷, 提出了新型Buck-Boost矩阵变换器, 采用双闭环控制策略进行控制. 介绍了该控制策略的基本原理与设计方法, 对比分析了该控制策略与滑模控制及离散滑模控制的各种特性, 并通过仿真对其控制效果进行了验证. 结果表明: 该控制策略不仅具有比滑模控制和离散滑模控制更加优良的动态性能, 而且还具有更强的谐波抑制能力, 其输出波形的谐波失真度更小, 稳态精度更高, 因而具有更好的应用价值.     

两能级量子系统的固定时间控制及鲁棒性

本文考虑刘维尔方程描述的两能级量子系统对于目标平衡态的固定时间控制问题.首先通过相干矢量和复数的指数形式对系统模型及控制目标进行等价变换,并借助合适的Lyapunov函数设计一个含分数幂的连续非光滑控制律,然后利用固定时间稳定性定理给出了系统实现固定时间收敛的条件.针对某些分数幂取值导致控制性能较差的情况,提出了两种非...     

A self-tuning PID control for a class of nonlinear systems based on the Lyapunov approach

In this paper, we will propose a self-tuning method for a class of nonlinear PID control systems based on Lyapunov approach. The three PID control gains are adjustable parameters and will be updated online with a stable adaptation mechanism such that the PID control law tracks certain feedback linearization control, which is previously designed. The stability of closed-loop nonlinear PID control system is analyzed and guaranteed by introducing a supervisory control and a modified adaptation law with projection. Finally, a tracking control of an inverted pendulum system is illustrated to demonstrate the control performance by using the proposed method.