瓦斯是煤矿生产五大灾害之一，能够造成特大事故，夺去工人宝贵的生命。做好瓦斯检测工作是为了及时掌握矿井瓦斯的变化情况，以采取相应的措施，防止瓦斯事故的发生，实现矿井的安全生产。针对瓦斯检测中的实际问题，本文提出了一种基于Duffing混沌系统的瓦斯信号检测方法，并利用单片机设计了瓦斯检测报警系统。 本文采用混沌理论中的Duffing系统作为设计依据，Duffing系统在检测信号时具有良好的抗噪性能，将其用于对瓦斯的检测当中，能有效抑制井下工作面的噪声在瓦斯检测时的影响。而瓦斯检测报警系统也能准确地测得瓦斯浓度并在超过限定浓度时报警，更好地保证井下工作面的安全。 本文详细说明了Duffing混沌系统检测信号的方法，包括已知频率信号幅值的检测方法和对未知信号的频率检测方法，并且为了进一步减小噪声对瓦斯信号检测的影响，提出了自相关和混沌系统相结合的检测方法。通过大量的仿真实验证明了其在瓦斯检测中的有效性和实用性,并对Duffing混沌系统在瓦斯检测中的应用作了展望，希望能对瓦斯检测的研究有所帮助。

Coal mine gas is one of the five major disasters, which can result in serious accidents and take away the precious lives of workers. In order to grasp the changes in coal mine gas timely, and to take appropriate measures,gas detection will be do well. Preventing gas accidents and achieving mine production safety are the focus of the study in many countries. Combined with the practical problems in the gas detection, this paper presents a chaos theory-based signal detection method of gas, and use of single chip design microcomputer for a gas detection and alarm systems. This paper uses the Duffing system in chaos theory as a theoretical basis. Duffing system in the detection signal has good noise immunity, which be used for the detection of gas, can effectively suppress the noise in mining face when gas is detected. The gas detection and alarm system can be accurately measured gas concentration and alarm when the gas concentration exceeds the limit, to ensure the safety better of mining face. This paper introduces the method of Duffing system detection signals in detail, including the detection method of known frequency signal amplitude and the frequency detection method of unkown signal. And the detection method which combines the autocorrelator with the chaotic system is proposed to further reduce the noise impact on the gas signal detection. A large number of simulation results show its usefulness and practicality in gas detection. This paper also raises expectations of the application of Chaotic system in the gas detection, hoping to help the study of gas detection.