第五章 速度转速和加速度的测量PPT课件.ppt

Gyroscope angular velocity measurement Basic characteristics of gyroscope Gyroscopic inertia(定轴性)：当陀螺仪的转子高速旋转时，如果不受任何外加力矩的作用，其主轴将稳定地保持在惯性空间初始方向上，这种特性称为陀螺仪定轴性或者稳定性。 角动量H越大，摩擦力矩越小，则主轴方向越稳定。 Gyroscope angular velocity measurement Basic characteristics of gyroscope Gyro-precession(进动性)：当转子高速旋转时，如果外加力矩M作用在陀螺仪的某一框架旋转轴上，迫使主轴绕另一框架的轴旋转，主轴以最短的途径向外力矩的方向靠拢。 在实际使用中如果内框架和外框架重合，陀螺仪将会失去了一个自由度，这种情况被称为“环架自锁”。 陀螺的进动是没有惯性滞后 Gyroscope angular velocity measurement 微分陀螺仪角速度测量 Gyroscope angular velocity measurement Fibre-optic?gyroscope Invented with Sagnac effect 光纤陀螺对角速度的敏感轴是单轴，常使用三个或四个光纤陀螺构成惯性测量组合 Velocity measurement using timing method Rotation speed measurement Measuring method Expressed by revolution per minute. That is r/min By measuring principle: 模拟法 计数法 同步法 By transforming mode： 机械式 电气式 光电式 频闪式 Centrifugal tachometer 离心式转速表具有测量结果显示直观、成本低、运行可靠、坚固耐用等优点，故在生产、维修现场使用较多。但是离心式转速表的测量原理简单，测量精度相对较低。 Photoelectric tachomer 接触式 非接触式 Chapter 7 Measurement of velocity, acceleration and vibration School of mechanical and power engineering/Henan polytechnic university Contents 7.1 Overview 7.2 Measurement of Velocity 7.3 Measurement of Acceleration 7.4 Vibration test Chapter Seven Measurement of velocity, acceleration and vibration 7.1 Overview Measurement of velocity and acceleration for vehicle, train, ship, plane, etc，and that of their moving attitude Rotational velocity for output shaft speed of engine and generator Velocity of rolled plate, strip, bar,?tubing material Measurement of vibration for large devices and engineering Applications in inertial?navigation 7.1 Overview Velocity：a vector which shows the direction and rate of motion. 物体直线运动时单位时间内的位移量，m/s Acceleration：a vector which shows the direction and magnitude of changes in velocity.物体运动时单位时间内的速度增量，m/s2 Rotational Velocity：物体运动时单位时间内的转数，r/min Angular Velocity：物体单位时间内转过的角度，rad/s Contents 7.1 Overview 7.2 Measurement of Velocity 7.3 Measurement of Acceleration 7.4 Vibration test Chapter Seven Measurement of velo