Research On Detection And Feature Extraction Of Ship Radiated Noise

In recent years,with the development of the marine environment,economic development and military applications have become more and more demanding for ship radiated noise detection and feature extraction technology.The variability of the marine environment and the uniqueness of the underwater acoustic channel make the detection and feature extraction of ship radiated noise become a major challenge in hydro-acoustic signal processing.Therefore,this paper mainly research on detection and feature extraction of ship radiated noise.The main research points are as follows:(1)A double Duffing oscillator detection model is proposed based on the single Duffing oscillator detection model.The single Duffing oscillator and the double Duffing oscillator detection model are used to detect the analog signals,and the detection performance is analyzed.The experimental results show that the double Duffing oscillator has better anti-noise performance and the timing diagram of the system output is clearer.(2)In order to solve the problem that double Duffing oscillator only detect the same frequency signal,an intermittent chaotic detection method based on double Duffing oscillator is used.The intermittent chaos detection method mainly includes the intermittent chaos detection method of chaotic oscillator columns and the intermittent chaotic detection method with variable step size.The intermittent chaos detection method of chaotic oscillator columns detects the measured signal by changing the frequency of the built-in strategy of the system.The experimental simulation proves that the method is feasible,but lead to the high computational complexity.The intermittent chaotic detection method with variable step size detects the measured signal by changing the solution step size of the system,which solves the problem of high computational complexity of the chaotic oscillator column method.These two methods are used to detect ship radiated noise.The experimental results show that both methods are effective,and the system with variable step size intermittent chaos detection has lower computational complexity and better detection performance.(3)A ship radiated noise detection algorithm based on non-local mean(NLM),double Duffing,and permutation entropy(PE)is proposed.NLM is used to reduce the noise of the signal to be measured,which can effectively reduce the influence of noise on the detection performance of the system.PE is used to quantitatively determine the output state of the system,which can reduce the influence of human observation errors on the detection results.NLM-double Duffing-PE is applied to detect the ship radiated noise,and the experimental results show that the proposed method has better detection performance than the double Duffing-PE detection method.(4)A new method based on variational mode decomposition(VMD),Fluctuation dispersion entropy and self-organizing feature maps(SOM)for ship radiated noise featureextraction is proposed,and the feasibility of this method for feature extraction of ship radiated noise is studied.This method is used to extract the features of three types of chaotic signals which proved the feasibility of the method.This method is used to extract the characteristics of ship radiated noise,and the experimental results show that the method has better separability.