Based On Parameter Perturbations The Hyperchaotic Underground Positioning Communications Anti-collision Scheme

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.