基于NI数据采集卡的微悬臂梁品质因数调谐

品质因数Q是影响微悬臂梁灵敏度的一个重要物理参量,是衡量微悬臂梁振动特性的重要指标,它与微悬臂梁振动所受到的环境阻尼成反比。微悬臂梁应用于液体等大阻尼环境中时,由于阻尼作用,品质因数降低,灵敏度及分辨力会降低。因此品质因数的调制对于提高仪器检测灵敏度和分辨力具有重要意义。本文提出一种基于NI数据采集卡的微悬臂梁品质因数的数字调控方法,根据振动反馈信号来实时调控振动激励信号的振幅,以调控品质因数Q的值。实验表明,这种品质因数Q控制方法能够有效地增大品质因数Q的值。

Tuning the quality factor of micro-cantilever based on NI data aquisition card

Quality factor is an important physical parameter of micro-cantilever and an important pointer of the performance of micro-cantilever,which is inversely proportional to the subjected damping of micro-cantilever.When a micro-cantilever works in a situation with large damping such as the liquid condition,the quality factors decrease because of the effect of the liquid damping.The sensitivity and identify of micro-cantilever will drop due to the decrease of the quality factor.A novel method,by means of which the vibration excitation signal's amplitude is tuned according to vibration feedback signal,based on NI data acquisition card to tune quality factor is presented.It has been proved by experiments that this method can efficiently increase the quality factor.