高精度机械振动频率测量仪设计  

Design of High Precise Mechanical Vibration Cymometer

作　　者：张兴红[1] 何涛[1] 邱磊[1] 陈鑫[1] 

机构地区：[1]重庆理工大学时栅传感及先进检测技术重庆市重点实验室,重庆400054

出　　处：《机械科学与技术》2016年第1期126-131,共6页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(51275551);重庆市自然科学基金项目(cstc2012jjA70004)资助

摘　　要：在机械设备的故障诊断中,频率是最重要的检测对象之一。很多机械设备在正常工作时,机械振动幅度较低,为了方便、快捷地对设备的振动频率进行检测,根据能量守恒定律,设计了一种特殊的振动测量传感器,该传感器的底部装有可以传输振动特性液体介质;中部是圆锥台结构的气体段,该圆锥台气体段底部圆直径大于顶部圆直径,当振动特性从底部传到顶部时,由于相同的能量从面积较大的部位集中到面积较小的部位,气体段顶部的振幅就会大于底部的振幅,从而实现了振动幅度的机械放大;该传感器的顶部是电容传感器,电容的大小会随着电容下极板的振动而改变,从而把被测非电量的变化转化为电信号的变化。在硬件处理电路中,采用全差分放大电路对电信号进行二次放大,利用模数转换器对二次放大的模拟信号进行采样。通过软件插补细分算法实现0.244 ns级的时间测量,从而实现高精度的频率测量。The frequency is one of the most important test objects in the fault diagnosis of mechanical equipment.The vibration amplitude is low when the mechanical equipment is in normal operation. In order to detect the vibration frequency quickly and easily,a kind of special vibration measurement sensors is designed according to the law of conservation of energy. The bottom of the sensor is equipped with a liquid medium which can transmit vibration characteristics; the central gas section is a truncated cone structure which the diameter of bottom is greater than the diameter of the top. Due to the same energy concentrated into smaller parts from the area of the larger part,the amplitude of the top is greater than that of the bottom when the vibration characteristics from bottom to top; The sensor is the capacitance sensor at the top,the capacity of the capacitor will change with the vibration of bottom plate. In the hardware processing circuit,a fully differential amplifier circuit is used to amplify electrical signal,amplified analog signal is sampled by high resolution ADC. Nanosecond precision time is measured through software subdivision algorithm,so as to realize the frequency measurement of high precision.

关 键 词：振动测量传感器 电容电压转换 细分插补算法 精密测量 

分 类 号：TP274.5[自动化与计算机技术—检测技术与自动化装置]