The influence of a rigid spherical baffle on the response of a uniform circular microphone array （UCA） is analyzed and two eigen-beam beamforming arrays are designed in the eigen-beam subspaee derived from the sound...The influence of a rigid spherical baffle on the response of a uniform circular microphone array （UCA） is analyzed and two eigen-beam beamforming arrays are designed in the eigen-beam subspaee derived from the soundfield decomposition. Expressions of white noise gain （WNG） and directivity index （DI） are derived for the designed arrays. Performance analyses are carried out for the designed arrays and compared between those of the delay-and-sum beamforming array using UCA with and without a rigid sphere. Computer simulations demonstrate that the designed arrays have frequency-independent directivity with the cost of reduced robustness at low frequency band. The delay-and-sum beamforming array has constant WNG at all frequencies, while its directivity of which is reduced at low frequency band. The rigid sphere can improve the robustness for all the arrays.展开更多
The nearfield error sensing approach, which is one of the key problems encountered in the implementation of active acoustic structure, is investigated theoretically. The basic idea involves a limited number of PVDF fi...The nearfield error sensing approach, which is one of the key problems encountered in the implementation of active acoustic structure, is investigated theoretically. The basic idea involves a limited number of PVDF film pairs be boned to the surface of the primary panel and secondary panels for measuring the total radiated sound power. In this paper, first, a theoretical model associated with the active acoustic structure is established. Second, the formulae for the shape coefficient of the PVDF pairs are derived based on the acoustic radiation modes and a PVDF sensing model. Finally, a number of computer simulations are performed and the shape of the PVDF pairs and corresponding reduction in the radiated sound power are calculated. The results demonstrate the feasibility of the proposed nearfield error sensing strategy.展开更多
文摘The influence of a rigid spherical baffle on the response of a uniform circular microphone array （UCA） is analyzed and two eigen-beam beamforming arrays are designed in the eigen-beam subspaee derived from the soundfield decomposition. Expressions of white noise gain （WNG） and directivity index （DI） are derived for the designed arrays. Performance analyses are carried out for the designed arrays and compared between those of the delay-and-sum beamforming array using UCA with and without a rigid sphere. Computer simulations demonstrate that the designed arrays have frequency-independent directivity with the cost of reduced robustness at low frequency band. The delay-and-sum beamforming array has constant WNG at all frequencies, while its directivity of which is reduced at low frequency band. The rigid sphere can improve the robustness for all the arrays.
基金This work was supported by the National Natural Science Foundation of China (No. 10274060)The authors grateful acknowledge the support of this work by the National Natural Science Foundation of China under grant No. 10274060.
文摘The nearfield error sensing approach, which is one of the key problems encountered in the implementation of active acoustic structure, is investigated theoretically. The basic idea involves a limited number of PVDF film pairs be boned to the surface of the primary panel and secondary panels for measuring the total radiated sound power. In this paper, first, a theoretical model associated with the active acoustic structure is established. Second, the formulae for the shape coefficient of the PVDF pairs are derived based on the acoustic radiation modes and a PVDF sensing model. Finally, a number of computer simulations are performed and the shape of the PVDF pairs and corresponding reduction in the radiated sound power are calculated. The results demonstrate the feasibility of the proposed nearfield error sensing strategy.
