Abstract: According to the laser gyro’s phase frequency characteristics this paper analyzed the influence of phase delay on realtime and mobility of missile control system, then studied the factors that cause phase delay of laser gyro, and pointed out that the vibration isolator does not bring phase delay, and FIR filter is the main factor for phase delay of laser gyro.Based on the angle vibration table and inertial measurement unit(IMU) body, four test states were designed and a practical test with phase frequency characteristics of laser gyro was conducted  using sine excitation method. The test results show that the vibration isolator’s delay time is no more than 0.051 ms and the delay time mainly comes from FIR filter, which is in accord with the theoretical analysis results.  

Key words: laser gyro, inertial measurement unit (IMU), delaytime, finite impulse response(FIR), angular vibration table