共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
3.
利用非线性反馈控制实现陈氏混沌系统在有界条件下对任意信号的追踪.根据系统结构特点选取合适的反馈方式.设计非线性控制律.并由Lyapunov直接方法证明误差信号渐近稳定于零且所有变量满足有界条件.数值研究结果表明.受控系统可对任意形式光滑参考信号(包括其他混沌系统的输出信号)进行追踪.该方法是一种物理可实现的稳定追踪控制方法.也可用于不同混沌系统之间的异结构同步. 相似文献
4.
5.
6.
7.
8.
9.
在仅能得到混沌发送信号并能获得足够多未加通信信息的发送信号的情况下,分别对通信信息调制入和未调制入混沌发送系统的两类混沌保密通信系统进行研究。首先用发送信号进行系统重构,然后用重构系统以及未加通信信息的重构点为领域对加有通信信息的发送信号进行一下步预测。文中推导出发送信号、预测信号之差与通信信息之间的关系,并从发送信号中直接提取通信信号。以Lorenz系统为例说明本文结论。 相似文献
10.
由于分数阶混沌动力学系统比整数阶系统具有更复杂的动力学特性,且能为图像加密方案提供更多的自由度,基于分数阶陈氏混沌系统,提出了一种图像加密方法。在发送端,驱动系统产生混沌信号,利用混沌信号扰乱明文图像的像素位置,将扰乱后的图像掩盖在混沌信号中,得到传输的密文图像。在接收端,通过同步系统去掩盖,进行像素位置扰乱的逆操作,恢复明文图像。最后对提出的加密算法进行了安全性分析。实验结果表明,该加密算法安全性高,具有良好的研究价值和应用前景 相似文献
11.
Ebru Karakose Muhsin Tunay Gencoglu Mehmet Karakose Orhan Yaman Ilhan Aydin Erhan Akin 《Journal of Intelligent Manufacturing》2018,29(4):839-856
pantograph–catenary system is one of the critical components used in electrical trains. It ensures the transmission of the electrical energy to the train taken from the substation that is required for electrical trains. The condition monitoring and early diagnosis for pantograph–catenary systems are very important in terms of rail transport disruption. In this study, a new method is proposed for arc detection in the pantograph–catenary system based signal processing and S-transform. Arc detection and condition monitoring were achieved by using current signals received from a real pantograph–catenary system. Firstly, model based current data for pantograph–catenary system is obtained from Mayr arc model. The method with S-transform is developed by using this current data. Noises on the current signal are eliminated by applying a low pass filter to the current signal. The peak values of the noiseless signals are determined by taking absolute values of these signals in a certain frequency range. After the data of the peak points has been normalized, a new signal will be obtained by combining these points via a linear interpolation method. The frequency-time analysis was realized by applying S-transform on the signal obtained from peak values. Feature extraction that obtained by S-matrix was used in the fuzzy system. The current signal is detected the contdition as healthy or faulty by using the outputs of the fuzzy system. Furthermore the real-time processing of the proposed method is examined by applying to the current signal received from a locomotive. 相似文献
12.
Problems related to the integrated design of robust fault detection (FD) systems are studied. First, it is revealed that due to the time window introduced to realize the 2-norm based evaluation function, an optimal design of a FD system with the 2-norm based evaluation function may not ensure the expected optimal performance when the system is realized in real applications. To solve this problem, an integrated design method of FD systems using the absolute value of residual signal as evaluation function is then proposed. It leads to a residual generator which is much easier to be realized. Different from the usual 2-norm based approaches whose mathematical basis is the relationship between the energy of the output and input signals of a dynamic system, a relationship between the instant power of the output signal and the energy of the past input signal of a dynamic system is established and further used for FD system design. Another new kind of evaluation function based on the absolute value of wavelet transform of residual signal and the corresponding integrated design approach for FD systems are further proposed 相似文献
13.
14.
15.
基于操作系统调用的容错计算机系统同步技术研究 总被引:1,自引:0,他引:1
同步是实现基于表决的容错计算机系统的关键过程.现有的采用基于硬件或应用软件同步技术的系统存在设计和制造困难、兼客性差和难以使用等问题.提出了一种基于操作系统调用的同步机制;描述了其同步算法;介绍了在Linux操作系统上的实现.该同步机制对应用程序完全透明,同步点无需人工设置,同步算法由软件和硬件结合的方式实现.实验结果表明该同步机制是可行的,较好地达到了系统易设计和好使用的目标. 相似文献
16.
17.
Stochastic chaos synchronization using Unscented Kalman-Bucy Filter and sliding mode control 总被引:1,自引:0,他引:1
Mahdi HeydariHassan Salarieh Mehdi Behzad 《Mathematics and computers in simulation》2011,81(9):1770-1784
This paper presents an algorithm for synchronizing two different chaotic systems by using a combination of Unscented Kalman-Bucy Filter (UKBF) and sliding mode controller. It is assumed that the drive chaotic system is perturbed by white noise and shows stochastic chaotic behavior. In addition the output of the system does not contain the whole state variables of the system, and it is also affected by some independent white noise. By combining the UKBF and the sliding mode control, a synchronizing control law is proposed. Simulation results show the ability of the proposed method in synchronizing chaotic systems in presence of noise. 相似文献
18.
为了说明高动态环境中时间同步对于组合导航系统的重要性,在Kalman滤波方程的基础上,推导了时间同步误差与Kalman滤波结果之间的定性关系.提出一种利用GPS接收机中1PPS(Pulse Per Second)信号作为同步标签的时间同步方法,将IMU中的数据加上精确的时间标签,从而达到时间同步的目的.全部时间同步功能由FPGA实现,利用Verilog HDL语言进行开发,整体硬件结构简单而且适用范围广.试验结果显示了这种时间同步设计可以明显减小滤波结果的估计误差,有效的提高了组合导航系统的定位精度. 相似文献
19.
The notion of a synchronizing sequence plays an important role in the model-based testing of reactive systems, such as sequential circuits or communication protocols. The main problem in this approach is to find the shortest possible sequence which synchronizes the automaton being a model of the system under test. This can be done with a synchronizing algorithm. In this paper we analyze the synchronizing algorithms described in the literature, both exact (with exponential runtime) and greedy (polynomial). We investigate the implementation of the exact algorithm and show how this implementation can be optimized by use of some efficient data structures. We also propose a new greedy algorithm, which relies on some new heuristics. We compare our algorithms with the existing ones, with respect to both runtime and quality aspect. 相似文献
20.
利用混沌信号作为载体实现信息通讯,其关键问题是发射机系统与接收机系统的混沌同步。本文应用MATLAB(数值计算实验)对由两个三维混沌系统(Chua系统与Lorenz系统)构造的高维超混沌系统进行了动态模拟,实现了高维系统的混沌同步及其信息通讯的编码与解码过程。模拟结果表明,高维系统的同步可以通过各子系统的混沌同步逐级实现,而初级子系统的同步程度、抗干扰性以及稳定性决定了高维系统的同步能力,模拟过程可以对此进行有效的数值分析,为应用研究的技术实现提供了依据。 相似文献