It is important to specify the occurrence and cause of failure of machines without stopping the machines because of increased use of various complex industrial systems. In this study, two new diagnosis methods based o...It is important to specify the occurrence and cause of failure of machines without stopping the machines because of increased use of various complex industrial systems. In this study, two new diagnosis methods based on the correlation information between sound and vibration emitted from the machine are derived. First, a diagnostic method which can detect the part of machine with fault among the assumed several faults is proposed by measuring simultaneously the time series data on sound and vibration. Next, a diagnosis method based on the estimation of the changing information of correlation between sound and vibration is considered by using prior information in only normal situation. The effectiveness of the proposed theory is experimentally confirmed by applying it to the observed data emitted from a rotational machine driven by an electric motor.展开更多
This paper describes a fundamental consideration on our works on the design of general Bayes' filters for the state estimation of non-stationary, non-linear, and non-Gaussian environmental sound and vibration syst...This paper describes a fundamental consideration on our works on the design of general Bayes' filters for the state estimation of non-stationary, non-linear, and non-Gaussian environmental sound and vibration systems. We have discussed an essential point of several Bayes' filters proposed by using the orthogonal or non-orthogonal expansion form of Bayes' theorem. They can estimate any kinds of statistics of arbitrary function type of state variables including the lower and the higher order statistics connected with the Lx evaluation index in the environmental sound and vibration systems. Here, we have mainly focussed on giving the fundamental viewpoints of their design policies. Some new estimation methods and new results not yet published are included.展开更多
Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of th...Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of the pores of bubble-produce apparatus . Vibration reduction of a vessel in water due to the bubbly curtain was found.展开更多
The resonance sound radiation from submerged infinite elastic cylindricalshell, excited by internal harmonic line force, is investigated. The shell radiation power ispresented in terms of resonant modal radiation deri...The resonance sound radiation from submerged infinite elastic cylindricalshell, excited by internal harmonic line force, is investigated. The shell radiation power ispresented in terms of resonant modal radiation derived from resonance radiation theory (RRT). Theresonance radiation formulae are derived from classical Rayleigh normal mode solution, which areuseful for understanding the mechanism of sound radiation from submerged shells. As an example,numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seemsthat the results of RRT solutions are in good agreement with that of Rayleigh normal modesolutions.展开更多
文摘It is important to specify the occurrence and cause of failure of machines without stopping the machines because of increased use of various complex industrial systems. In this study, two new diagnosis methods based on the correlation information between sound and vibration emitted from the machine are derived. First, a diagnostic method which can detect the part of machine with fault among the assumed several faults is proposed by measuring simultaneously the time series data on sound and vibration. Next, a diagnosis method based on the estimation of the changing information of correlation between sound and vibration is considered by using prior information in only normal situation. The effectiveness of the proposed theory is experimentally confirmed by applying it to the observed data emitted from a rotational machine driven by an electric motor.
文摘This paper describes a fundamental consideration on our works on the design of general Bayes' filters for the state estimation of non-stationary, non-linear, and non-Gaussian environmental sound and vibration systems. We have discussed an essential point of several Bayes' filters proposed by using the orthogonal or non-orthogonal expansion form of Bayes' theorem. They can estimate any kinds of statistics of arbitrary function type of state variables including the lower and the higher order statistics connected with the Lx evaluation index in the environmental sound and vibration systems. Here, we have mainly focussed on giving the fundamental viewpoints of their design policies. Some new estimation methods and new results not yet published are included.
基金The project is supported by National Natural Science Foundation of China and Nationalshipbuilding Corporation
文摘Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of the pores of bubble-produce apparatus . Vibration reduction of a vessel in water due to the bubbly curtain was found.
基金This project is supported by National Natural Science Foundation of China(No.19974024).
文摘The resonance sound radiation from submerged infinite elastic cylindricalshell, excited by internal harmonic line force, is investigated. The shell radiation power ispresented in terms of resonant modal radiation derived from resonance radiation theory (RRT). Theresonance radiation formulae are derived from classical Rayleigh normal mode solution, which areuseful for understanding the mechanism of sound radiation from submerged shells. As an example,numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seemsthat the results of RRT solutions are in good agreement with that of Rayleigh normal modesolutions.
