多变量耦合实现双环掺铒光纤激光器混沌同步

根据双环掺铒光纤激光器的理论模型,提出多变量单向耦合法实现混沌同步,对主从系统模型进行数学推导,研究不同参数条件下双环掺铒光纤激光器的混沌同步,得到实现混沌同步的条件,并在Simulink平台下动态仿真。结果表明,衰减系数不同的两个双环掺铒光纤激光器,主激光器通过定向耦合器驱动从激光器,主从系统可以实现精确混沌同步,且随着反馈强度的增大,实现系统混沌同步的时间越短,反馈强度的取值范围由衰减系数和耦合系数确定;选取不同的系统初值,主从系统可实现混沌同步,系统初值对达到混沌同步时间的影响可忽略不计;在主从系统中引入随机高斯噪声,主从系统仍可实现较好的混沌同步。     

异结构时滞不确定混沌系统的同步/反同步控制及其应用

为了研究具有不同参数的两个不确定时滞混沌系统的同步与反同步控制及在保密通信中的应用,首先对反馈时滞Lorenz混沌系统的系统参数进行重新设计,并引入正弦函数扰动,获得两个具有不同吸引子的时滞混沌系统.采用主动控制方法实现了具有不同参数的时滞混沌系统的同步及反同步控制.为了实现保密通信,将明文信号参与混沌运算,并结合混沌...     

光电混沌同步在高速光保密通信中的应用

对光电双延时反馈混沌系统在高速光保密通信中的应用做了仿真实验研究.建立了光电双延时反馈混沌同步的理论模型,利用Optisystem光通信系统仿真软件搭建了相应的仿真实验系统.分析了混沌同步通信系统的同步性能,当主从光电混沌系统参数相同时,同步误差为仅为0.0096,相关系数达到0.97,通信速率为5Gb/s时的系统误码率为5.51e-006.     

混沌系统同步的抗干扰优化设计

本文研究混沌系统同步的抗信道噪声和参数失配干扰优化设计问题。以非线性反馈混沌同步方案为基础，推导出一种抗干扰优化设计方法。对蔡氏电路的仿真实验表明，用该方法设计的混沌同步系统具有较强的抗干扰能力。     

超混沌系统的一种同步方法

本文提出了超混沌系统的一种同步方法。先将系统的部分状态变量差进行反馈，然后通过滤波积分器，可以使两个结构相同的超混沌系统达到浊 同步。     

半导体激光器的混沌驱动同步

利用混沌驱动同步法研究了在电流调制下的半导体激光器的混沌同步。首先数值计算了系统最大Lyapunov指数随调制强度的变化情况,确定了激光器处于混沌态的参数区间。然后分别实现了同地激光器系统和异地激光器系统的混沌驱动同步。响应激光器间相关系数的数值计算表明,两种激光器系统均能达到很好的混沌同步。以三个响应激光器为例,将响应系统推广到多个激光器,并且实现了两种激光器系统的混沌同步。     

统一混沌系统与其变形系统间的间歇反馈同步控制

采用间歇反馈控制方法,研究了统一混沌系统与其变形系统间的同步控制问题。通过合理设计间歇反馈控制器,将同步问题转化为误差动力学系统方程在原点处的收敛问题。根据连续系统的稳定性准则及相关实验,推导出了满足同步条件的同步定理。分析了初始值X(0)和Y(0)、反馈系数k、比例因子D、步长h以及统一系统参数对同步系统的同步性能的影响。最后,采用间隙反馈同步方案,设计了一个混沌掩盖保密通信系统,并进行了仿真研究。仿真实验研究证明了该同步方法的有效性。     

基于量子遗传算法的永磁同步电动机混沌运动的同步控制

混沌同步是当代非线性与控制学科中的一个热点问题。针对永磁同步电动机中混沌同步,反馈反同步法在整定反馈增益矩阵参数时存在困难,利用量子遗传算法对反馈增益矩阵进行参数优化,从而克服反馈增益中参数不易整定的缺陷。数值仿真实验表明,利用量子遗传算法结合反馈反同步法能够使初始状态不同、运动轨迹不同的两个混沌系统在短时间内迅速达到同步,可以是系统达到很好的动态特性,验证了该方法的有效性,对电动机运动的稳定性具有较好的价值。     

半导体激光器混沌双向保密通信系统理论研究

提出外部光注入半导体激光器激光混沌全光耦合-反馈同步系统，进行激光器系统稳定性动力学分析并计算出最大Lyapunov指数，导出系统的同步误差扰动方程以及系统有混沌隐藏编码时的同步误差公式和解调公式，数值证明并模拟实现了系统的混沌同步，分析同步瞬态响应和噪声影响，该系统具有较强的抗干扰能力。模拟具有正弦调制信号的调制频率0．2GHz混沌模拟通信和数字信号调制速率0．2Gb／s的混沌数字通信以及调制速率0．05Gb／s混沌键控通信的应用，特别分析了系统解码特性和调制带宽，系统无论是在时域还是在频域，都具有非常好的保密性，该系统可以作为混沌双向保密通信使用。研究表明系统准许在一定范围内可以有参数失配，系统的实际应用是有可能的。     

新型三激光器结构的混沌同步特性

设计了一种新型的闭环双向三激光器混沌保密通信系统,驱动激光器基于延时外光反馈,两个参数完全相同的响应激光器在自身延时反馈和驱动激光器的驱动下实现混沌同步。建立了相应的理论模型,研究了系统的分岔特性、同步性以及内部参数失配对其同步性能的影响,并与不含自身光反馈的开环系统进行了比较。研究结果表明,当系统参数满足一定条件时,两个响应激光器的关联极值接近于1,而驱动激光器和响应激光器的相关性很小。与开环系统相比,该系统的载波带宽拓宽了约1.99GHz,对参数失配比较敏感并具有更好的保密性能。     

基于脉冲控制的时延异构多智能体编队控制

为提高编队系统鲁棒性,降低系统对通信条件的要求,针对异构多智能体系统的编队控制问题,提出一种基于脉冲控制的编队控制方法.考虑异构多智能体的切换拓扑与变时延情况,根据一致性理论,提出基于领航跟随者模型的脉冲控制协议.利用矩阵分析方法将异构多智能体编队系统的变时延问题转化为时延上界问题,通过构造Lyapunov函数并利用Lyapunov稳定理论得到系统实现编队控制一致性的充分条件.同时,为比较不同控制协议的优劣性,提出切换拓扑下多智能体编队控制的平均通信代价指标.仿真结果验证了所提脉冲控制方法的有效性和优越性.     

基于模糊理论的料位自动控制技术分析

在现代工业的控制系统中,PLC/DCS控制系统具有广泛的应用,但是对于参与控制的模拟量,尤其是闭环控制,就要复杂得多,运用模糊控制理论设计模拟量的控制算法,使得控制由点控制变成区段控制,突破了计算机控制的局限性。以料位控制系统为例,由于采用了模糊控制理论,该系统电路结构简单、程序清晰、系统可靠性高,完全闭合地实现了根据设备中物料的量控制速度,对实现该类设备的自动化具有重要意义。     

Inverse optimal control problem for linear discrete-time systems

In the letter, the inverse control problem for linear discretetime systems is considered. A criterion is stated for the optimality of a linear feedback control for single-input systems. Differences with continuous-time systems are discussed.     

Modeling and design methodology for mechatronic systems

The integration of mechanical systems and microelectronics opens many new possibilities for process design and automatic functions. After discussing the mutual interrelations between the design of the mechanical system and digital electronic system the different ways of integration within mechatronic systems and the resulting properties are described. The information processing can be organized in multi levels, ranging from low level control through supervision to general process management. In connection with knowledge bases and inference mechanisms, intelligent control systems result. The design of control systems for mechanical systems is described, from modeling, identification to adaptive control for nonlinear systems. This is followed by solving supervision tasks with fault diagnosis. Then design tools for mechatronic systems are considered and examples of applications are given, like adaptive control of electromagnetic and pneumatic actuators, adaptive semiactive shock absorbers for vehicle suspension, and electronic drive-chain damping.     

非线性协调控制系统状态方程的级数解

针对非线性系统,为了合理利用变量间的有益耦合、消除有害的关联,提出了具有扰动补偿的非线性协调控制原则.根据控制原则,建立了非线性协调控制系统的状态方程,基于该方程导出了对于外界扰动的完全补偿条件,进而给出了完全补偿协调控制系统非线性状态方程.采用直接试探法,求得了该方程的任意阶级数解析解,这是一种有效的非线性系统状态方程的近似求解方法.     

Constrained Control of Positive Discrete-Time Systems With Delays

This brief addresses the control problem of linear time-invariant discrete-time systems with delays. The control is under positivity constraint, which means that the resulting closed-loop systems are not only stable, but also positive. The contribution lies in three aspects. First, a necessary and sufficient condition is established for the existence of such controllers for discrete-time delayed systems. Second, a sufficient condition is provided under the additional constraint of bounded control, which means that the control inputs and the states of the closed-loop systems are bounded. Third, sufficient conditions are proposed for discrete-time delayed systems with uncertainties, whether or not bounded control is considered. All the results are formulated as linear programming problems, hence easy to be verified. And the controllers are explicitly constructed if existent.     

多领航者网络化系统的动态群集运动

针对时变动态切换拓扑下具有多个领航者的网络化系统群集运动问题,本文分别给出了一阶／二阶网络化系统的控制算法,并对所提出的控制算法进行了理论分析。运用现代控制理论、代数图论和矩阵论等分析工具,研究了当通信拓扑为动态联合连通时,系统可以实现群集运动,即系统的运动轨迹都收敛到由多个领航者构成的凸包中。通过对系统信息拓扑连通部分的进一步研究,得到了二阶网络化系统群集运动的约束条件。最后应用仿真实验验证了结论的正确性。     

Vom Lenkrad zum Joystick

Embedded computer systems are increasingly being entrusted with vital control tasks in safety critical applications. Due to their immense versatility they are replacing conventional relay- and mechanical control systems as well as pneumatic systems. The high complexity inherent to computer control systems, however, makes the assessment and proof of their reliability more difficult. While conventional failure mode analysis has proven effective for mechanical and relay control, embedded systems rather require probabilistic and metrological approaches. In this context our paper will concentrate on some aspects of fail-silent architectures as an alternative to TMR systems, system level reliability modelling and fault injection for the assessment of fault tolerance. The implications of this approach will be demonstrated for an automotive steer-by-wire system.     

Evolution of the power control techniques for DS-CDMA toward 3G wireless communication systems

In this article we present a survey of the power control techniques for modern wireless DS-CDMA communication systems. Power control is the single most important system requirement for DS-CDMA systems. Well-defined power control is essential for proper functioning of the DS-CDMA system. In the absence of power control the effect of near⁄far phenomena is dominant, and the capacity of the DS-CDMA mobile system is very low, even lower than that of mobile systems based on FDMA. However, when the power control in DS-CDMA systems exists, it allows users to share resources of the system equally between themselves. Also, with a proper power control it is possible to lower total transmitting power of the mobiles and prolong the battery life.     

Robust motion/force control of uncertain holonomic/nonholonomic mechanical systems

In this paper, robust control strategies are presented systematically for both holonomic mechanical systems and a large class of nonholonomic mechanical systems in the presence of uncertainties and disturbances. First, robust control strategies are presented for both kinds of systems using the bounds of system parameters, respectively. Then, adaptive robust control strategies are presented by tuning the parameter estimates online. Proportional plus integral feedback control is used for force control for the benefit of real-time implementation. The proposed control strategies guarantee that the system motion converges to the desired manifold with prescribed performance while the constraint force remains bounded.