摘要
在研究扬声器振膜的非线性振动时,通常使用Volterra模型进行建模分析。由于受到误差的影响,该模型仅适用于微弱的非线性现象,增大激励电压,频响预测结果的误差逐渐增大。针对这一问题,一种改进的扬声器Volterra模型被提出。该模型引入了振膜平衡位置偏移量对非线性参数的影响,并且在计算位移响应时引入高阶核函数的互调项,使位移响应预测结果更为精确。为了验证模型,搭建了一套可以测量振膜瞬时位移的激光测量系统。实验中测量并计算了振膜平衡位置偏移量和位移的基频响应。结果表明,改进的扬声器Volterra模型与实验结果的一致性较传统模型更好。
Voherra model is often applied in analyzing nonlinear vibration of a loudspeaker diaphragm. However, with higher input voltage, the error of frequency response has a trend of becoming larger. Therefore, the model is applicable only for analysis of systems with weak nonlinearity. Here, an improved model was proposed. In order to provide a more accurate result, the displacement of the rest position of the diaphragm was adopted to modify the nonlinear parameters, and the high-order intermodulation terms were induced in calculating displacement response. A laser measurement system used for measuring the instant displacement of the diaphragm was built. In tests, the displacement of the rest position and the linear response of displacement were recorded and calculated. The result of the improved Voherra model showed a better agreement with the test one comparing with the conventional model.
出处
《振动与冲击》
EI
CSCD
北大核心
2012年第11期158-163,共6页
Journal of Vibration and Shock
关键词
扬声器非线性
Volterra模型
位移响应
平衡位置偏移量
loudspeaker nonlinearities
voherra model
displacement frequency response
displacement of rest position
