含无损传输线的约瑟夫森结电磁系统中的分岔与混沌

 建立了含无损传输线的约瑟夫森结电磁系统左端点处电压正向行波分量的一维Poincaré映射模型,运用非线性动力学理论分析了映射定点的稳定性。通过数值计算得到了映射随电压反射系数变化的分岔图,详细分析了系统随参数变化的动态演化过程。结果表明在一定参数条件下,该电磁系统中存在着分岔、混沌、周期吸引子共存、混沌吸引子共存以及周期与混沌吸引子共存等复杂的非线性动力学行为。     

一个具有无限多吸引子共存的新混沌系统的动力学分析及其电路实现

提出了一个新的具有超多稳定性的三维连续自治混沌系统,该系统仅有2个非线性项.对系统的耗散性、平衡点的稳定性进行了定量分析,并利用分岔图、Lyapunov指数、彭加莱截面和吸引子相图分析了系统参数以及初值对其动力学行为的影响.在参数固定的情况下,分析初值变化的分岔图,得到了无限多种共存吸引子.通过采用模拟开关电子元件设计实现了该系统,同时运用Multisim软件仿真了该系统的混沌电路.结论证明电路仿真与数值仿真结果一致.     

分数阶超混沌系统的动力学分析及同步

对一个新的超混沌系统通过分数阶线性系统稳定性理论分析得出其分数阶形式,并利用matlab仿真得出该系统的混沌吸引子图像.接着对该分数阶系统的同阶数和不同阶数两种形式进行异结构的同步分析,设计自适应同步控制器,实现该系统的异结构同步,数值仿真的结果表明设计控制器很好的实现了驱动系统和响应系统的同步.     

多电飞机高压直流电力系统稳定性分析

大量使用的恒功率负载对飞机电网稳定性有至关重要的影响.分析了恒功率负载的特性,建立了多电飞机高压直流电力系统的等效电路模型,基于小信号分析法研究了恒功率负载变化对系统稳定性的影响.研究结果表明,恒功率负载增大会使系统的稳定性降低,而为其并联容性负载可以延缓稳定性降低的趋势.为保护系统,设计了参考电压控制器,重载时降低负载线缆电流,补偿负载电压.基于Simulink平台建立了系统的时域仿真模型,仿真结果证明了稳定性分析的正确性和控制器设计的有效性.     

温度对光纤频率传输系统稳定性的影响及其补偿

为抑制温度对基于光纤的频率传输系统稳定性的影响,建立了相应的物理模型.并进行了定量分析.结果表明.温度的缓慢变化不会影响频标信号的短期稳定性.但会使其长期稳定性变差.因此,在高稳定光纤频率传输系统中.必须通过相位补偿来有效地抑制温度引入的相位噪声.在此基础上进行了仿真研究和实验检测.仿真结果表明,通过该补偿技术可以在环...     

新的分数阶混沌系统及其同步控制

研究了一个新的分数阶系统的混沌动力学行为.基于分数阶微积分理论和数值模拟,发现在该新的分数阶系统中存在混沌,并且得出该分数阶系统能产生混沌吸引子的最低阶数为2.49阶.根据分数阶动力系统稳定性理论,通过设计非线性控制器,实现了新的分数阶混沌系统的投影同步,该方法设计简便,并且不需要计算Lyapunov指数,数值模拟结果验证了该同步方法的有效性.     

产业融合环境下IMPS系统架构设计

针对建立大规模的IMPS系统的需求,给出了一种系统结构模型,以便满足系统对于大容量、稳定性、可扩展方面的要求.     

基于Matlab的控制系统分析

通过Matlab软件处理和仿真,分析所建立的控制系统模型的可行性.利用Matlab平台分析对系统传递函数的稳定性,利用Matlab软件得出系统的单位阶跃响应和脉冲响应,并利用Simulink对其仿真验证.通过分析发现,系统的稳定性是可以实现的.利用Matlab分析控制系统既简单、快捷、高效,而且Matlab平台为分析控制系统提供了极大的方便.     

线性时不变系统的稳定性分析

借助系统的零、极点分析研究了系统的稳定性.介绍了系统稳定性的概念、充分必要条件及判断方法.重点介绍了判断系统稳定性的方法.并举例说明了该方法在判断自动控制系统的稳定性及如何适当选取系统参数等的应用.     

大播出环境下的智能监控系统

详细介绍了在大播出的背景下智能监控系统建立的实现方式及主要功能.集中显示该系统所有监控设备的状态信息,以辅助值班人员实时观察和掌握设备运行状况,及时发现并解决问题,提高系统运行的安全性及稳定性.     

Global stability of generalized additive fuzzy systems

The paper explores the stability of a class of feedback fuzzy systems. The class consists of generalized additive fuzzy systems that compute a system output as a convex sum of linear operators, continuous versions of these systems are globally asymptotically stable if all rule matrices are stable (negative definite). So local rule stability leads to global system stability. This relationship between local and global system stability does not hold for the better known discrete versions of feedback fuzzy systems. A corollary shows that it does hold for the discrete versions in the special but practical case of diagonal rule matrices. The paper first reviews additive fuzzy systems and then extends them to the class of generalized additive fuzzy systems. It also derives the basic ratio structure of additive fuzzy systems and shows how supervised learning can tune their parameters     

A novel driver assist stability system for all-wheel-drive electric vehicles

A novel driver-assist stability system for all-wheel-drive electric vehicles is introduced. The system helps drivers maintain control in the event of a driving emergency, including heavy braking or obstacle avoidance. The system comprises a fuzzy logic system that independently controls wheel torque to prevent vehicle spin. Another fuzzy wheel slip controller is used to enhance vehicle stability and safety. A neural network is trained to generate the required reference for yaw rate. Vehicle true speed is estimated by a sensor data fusion method. The intrinsic robustness of fuzzy controllers allows the system to operate in different road conditions successfully. Moreover, the ease of implementing fuzzy controllers gives a potential for vehicle stability enhancement.     

A Type-2 Fuzzy Switching Control System for Biped Robots

In this paper, a type-2 fuzzy switching control system is proposed for a biped robot, which includes switched nonlinear system modeling, type-2 fuzzy control system design, and a type-2 fuzzy modeling algorithm. A new switched system model is proposed to represent the continuous-time dynamic and discrete-event dynamic of a walking biped as a whole, which is helpful to analyze the closed-loop stability of the biped locomotion. A type-2 fuzzy switching control system is proposed for the switched system model to guarantee the gait stability and to achieve a robust control performance with a simplified control scheme. Finally, we propose a new fuzzy c-mean variance algorithm for the type-2 fuzzy system modeling to capture the variance of each clustering means, which can translate random uncertainties of original data into rule uncertainties. Simulation results are reported to show the performance of the proposed control system model and algorithms.     

A new approach to numerical stability analysis of fuzzy controlsystems

The paper presents numerical methodology for the stability analysis of a fuzzy control system. The fuzzy control system analyzed is a closed-loop system controlled by a fuzzy logic controller (FLC) with singleton consequents. Compared with previous works based on numerical approaches (E. Kim et al., 1999), the method proposed in the paper employs two new strategies to release the conservatism of the previous methods: region-wise affine transformation and piecewise quadratic Lyapunov function. Finally, the effectiveness of the stability analysis is illustrated by a numerical example and its computer simulation     

Synchronization of Chaotic Systems Using Time-Delayed Fuzzy State-Feedback Controller

This paper presents the fuzzy-model-based control approach to synchronize two chaotic systems subject to parameter uncertainties. A fuzzy state-feedback controller using the system state of response chaotic system and the time-delayed system state of drive chaotic system is employed to realize the synchronization. The time delay which complicates the system dynamics makes the analysis difficult. To investigate the system stability and facilitate the design of fuzzy controller, Takagi-Sugeno (T-S) fuzzy models are employed to represent the system dynamics of the chaotic systems. Furthermore, the membership grades of the T-S fuzzy models become uncertain due to the existence of parameter uncertainties which further complicates the system analysis. To ease the stability analysis and produce less conservative analysis result, the membership functions of both T-S fuzzy models and fuzzy controller are considered. Stability conditions are derived using Lyapunov-based approach to aid the design of fuzzy state-feedback controller to synchronize the chaotic systems. Simulation examples are presented to illustrate the merits of the proposed approach.     

一种单片机温度模糊控制系统的实现

将模糊控制理论应用到单片机温度控制系统，根据电饭煲的温度控制规律，介绍了一种模糊电饭煲温度控制系统。系统软件设计采用定时中断的结构，核心为模糊控制器的实现。介绍了温度模糊控制器输入模糊化、模糊决策、输出逆模糊化等过程实现，并进行了实验研究。该系统具有实时性好、控制速度快、稳定性好等优点。     

Backing control problem of a mobile robot with multiple trailers:fuzzy modeling and LMI-based design

The paper presents backing control of computer simulated mobile robots with multiple trailers by fuzzy modeling and control. We deal with two kinds of mobile robots: a mobile robot with five trailers and a mobile robot with ten trailers. To design fuzzy controllers, nonlinear models of the mobile robots with multiple trailers are represented by Takagi-Sugeno fuzzy models (TS fuzzy model). Before making TS fuzzy models, we simplify the nonlinear dynamics of the mobile robots. Under an assumption, TS fuzzy models are made from the simplified nonlinear models. The so-called parallel distributed compensation (PDC) is employed to design fuzzy controllers from the TS fuzzy models. Next, we derive a stability condition based on the Lyapunov approach. The stability condition of the designed fuzzy control system is cast in terms of linear matrix inequalities (LMI's) since it is reduced to a problem of finding a common Lyapunov function for a set of Lyapunov inequalities. Convex optimization techniques based on LMI's are utilized to solve the problem of finding stable feedback gains and a common Lyapunov function for the designed fuzzy control system. The simulation results show the effects of the fuzzy modeling, the controller design via the PDC, and the stability analysis based on LMIs     

倒立摆系统的智能控制算法研究

倒立摆系统是一种典型的控制系统模型,能够将实际与理论相结合,可以开发出新的控制算法来应用在系统模型之上。采用模糊控制算法研究二级倒立摆系统的控制问题,设计模糊控制器控制倒立摆系统的稳定。实践证明,模糊控制算法对二级倒立摆系统是可行的。     

基于模糊自整定PID的汽轮机数字电液控制系统

基于模糊控制技术和汽轮机DEH系统的数学模型,将模糊自整定理论应用于汽轮机DEH系统,设计了一种适用于汽轮机数字电液控制系统的模糊自整定PID控制器。他利用偏差及偏差变化率作为模糊控制器的输入,并制定了模糊规则进行控制,实现PID参数的实时自整定,从而改善汽轮机调节系统的控制特性。仿真结果和分析表明在调节稳定性,超调量和自整定PID参数等方面,模糊自整定PID控制算法均优于传统PID控制算法。     

非线性系统的自适应模糊控制器设计

针对非线性系统,为获得更好的控制控制效果,设计了模糊自适应控制器。在模糊控制器的基础上根据反馈控制和调整参数向量的自适应律的求解,综合李雅普诺夫稳定理论设计了模糊自适应控制器,以满足系统的稳定性和控制效果。为验证控制器的有效性,将该控制器应用到二级倒立摆系统的稳定控制,仿真结果表明该控制器的控制效果良好,并与传统的控制方法相比较,其控制效果更佳。