Application of Wavelet Median Filter to Initial Alignment of Shaking Base
Jianzhao Huang · Piezoelectrics and Acoustooptics · 2013
The gyroscope and accelerometer is influenced greatly by the environmental interference noises when the initial alignment of SINS on the shaking base is carried out.Furthermore,the noise is difficult to be supressed effectively and in real time by using the low-pass filtering(LPF) or wavelet filtering independently.A mixed filtering method combined the wavelet threshold denoising and mediam filtering has been proposed to eliminate the signal noise in this work.The burst noise in the output signal is removed firstly by the median filter,then the vibration noise and white noise are filtered by wavelet threshold method.Therefore,the noise which is brought in by the shaking base can be lowered down effectively without reducing the precision of alignment.The experiment results show that the pre-filtering method presented in this paper has obvious effects in filtering the noise of signal output from vehicle navigation system,and the signal acquisition results while the engine is running are matching well with the static signals.And the simulation results show that this filtering method works well in the precise alignment of shaking base as an assist to SINS.