基于参数扰动超混沌的井下定位通信防碰撞方案

【作者】 于波；

【导师】 王中训；

【作者基本信息】 烟台大学 ， 信号与信息处理， 2010， 硕士

【摘要】 目前井下煤矿还普遍存在人员定位管理困难的问题,难以及时掌握井下人员动态分布情况,导致事故发生时,安全救护的效率低。因此,建立以灾害预防、事故救助、电子信息化管理为主要目标的信息化和智能化建设势在必行。本论文首先介绍了井下定位系统的应用背景,并对目前已有的定位系统进行介绍,分析其工作原理以及系统所必须要完成的功能。通过分析已有的各种井下定位通信方案的优缺点,确定使用在目前技术条件下综合效益最高(成本低,可靠性高)的RFID定位方案,并介绍了与RFID定位方案相关的芯片资料和通信总线特点。然后完成了基于“LPC2368处理器+nRF24L01+CAN总线”的基站硬件电路设计,并选取了该电路中的两个主要模块——CAN总线接口和nRF24L01接口电路的硬件和驱动程序设计进行详细说明；完成了基于’MSP430F2013处理器+nRF24101"的标签电路设计,探讨了MSP430处理器的低功耗技术应用方法,设计了MSP430F2013和nRF24L01之间的低功耗读写驱动程序。讨论了井下定位过程中容易出现的通信碰撞问题,分析了产生碰撞的原因,并在目前已有各种防碰撞方案的基础上,提出一种适合RFID方式井下定位的通信防碰撞方案——基于混沌的通信防碰撞方法。除了完成定位系统的电路设计和相应的软件设计以外,还介绍了混沌系统的基本概念,四个经典混沌系统的特点,以及混沌反控制技术的方法和研究目的。通过对一个近似时滞超混沌系统的分析,计算超混沌系统产生的吸引子的Lyapunov指数、关联维数、Kolmogorov墒、频谱和Poincare截面等混沌特征量,将之与Lorenz吸引子进行比较,从数值实验方面证明了近似时滞超混沌吸引子的复杂动力学特性。最后利用混沌的固有特性——类随机性和初值敏感性,设计了一个参数扰动超混沌系统,通过该系统可以得到完全真随机的信号,解决了井下定位系统的通信碰撞问题。更多还原

【Abstract】 Nowadays, the difficulty for managing underground people is popularly exists in coal mine because the distribution of underground workers is hard to find out. And then, it is always resulting in the inefficient rescue when accident happens. Therefore, it is imperative to establish information and intelligent construction of disaster prevention, accident assistance, and electronic information management.This paper first introduces the background of the application of underground positioning system, and also introduces the already existing positioning systems and analyses their working principles and the necessary functions.By analyzing the advantages and disadvantages of the various existing communication schemes for underground positioning systems, we determine to use the RFID positioning scheme which has the benefits of highest overall performance (low-cost, high reliability) under the current technology conditions, and introduce the chip documentation and communication bus features related with the RFID positioning scheme.Then the base station hardware circuit is designed which is based on "LPC2368 processor+ nRF24L01+CAN-bus", and two main modules of the circuit-CAN bus interface and nRF24L01 interface circuit are selected for illustrating the details of the hardware. The tag circuit is also designed based on "MSP430F2013 processor+nRF24L01", and the application methods of the MSP430 processor’s low-power technology are discussed and the low-power read-write drivers between MSP430F2013 and nRF24L01 are designed.The communication collision problems in the underground positioning system are discussed and the reasons of collision are analyzed. Based on the various existing anti-collision schemes currently used, a new communication anti-collision scheme which is suitable for RFID underground positioning is proposed:chaos-based communication anti-collision method.In addition to the realization of the circuit and software design for positioning systems, it also introduces the basic concepts of chaotic systems, the characteristics of the four classical chaotic systems, as well as methods and research purposes of chaotic anti-control technology. By analysis of a similar time-delay hyperchaotic system, the attractors’ dynamics characteristics, such as the Lyapunov exponents, correlation dimension, Kolmogorov entropy, frequency spectrum and Poincare section. By comparing it with the Lorenz attractor, from the numerical experiments it proves the complex dynamics of the hyperchaotic attractor.Finally, by using of the inherent characteristics of chaos-pseudo randomness and initial value sensitivity, we design a parameter perturbation hyperchaotic system, through which the system can get true random signal, solve the communication collision problem in underground positioning systems.更多还原