Method for designing digital filter applied in inertia device

Abstract

The invention relates to a method for designing a digital filter applied in an inertia device. The method is characterized by comprising the following steps of: determining an amplitude attenuation allowable value according to the precision of the inertia device, determining a phase delay allowable value according to the performance index of a strap-down inertial navigation system, and determining certain technical parameters of the filter according to the actual signal power spectrum analysis of the inertia device; designing a reference analog filter, converting the reference analog filter into an infinite impulse response (IIR) digital filter by using a bilinear transform method, observing a bode diagram in the filter parameter adjusting process, and performing off-line simulation calculation according to the actually measured data; and performing judgment by using de-noising effect, common cutoff frequency, amplitude attenuation and phase delay as fuzzy variables and using fuzzy rules to optimize the integral performance index. The digital filter designed by using the method can effectively filter the noise in the inertia device, meanwhile, controls the amplitude attenuation and the phase delay in an allowable range, and ensures the precision of the signals.

Description

Technical field The present invention relates to signal processing technology in the field of inertial navigation, in particular to a design method of digital filters applied to inertial devices. Background technique In the application of inertial navigation, inertial devices (gyro and accelerometer) give the angular velocity and acceleration signals of the carrier in real time, and the attitude angle and position information of the carrier are obtained after the integral solution, which directly determines the navigation accuracy. The strapdown inertial navigation system with inertial devices as the core component has a wide range of applications in modern military, aviation, aerospace and other fields, and is of great significance to the defense industry. Inertial devices are precision instruments, with high accuracy and wide dynamic range, which determine the guidance accuracy of a weapon about 70%. In the strapdown inertial navigation system, the inertial device is directl...

AI Technical Summary

Problems solved by technology

When traditional IIR digital filter design methods and steps are applied to inertial devices, they often only consider the denoising effect and system bandwidth, and do not consider the spectral characteristics of inertial device signals; do not consider the impact of amplitude attenuation and phase delay on device signal accuracy and system accuracy. impact; regardless of whether the overall performance metrics are optimal or suboptimal

Traditional design methods can easily cause deformation or distortion of the signal, resulting in a decrease in signal accuracy

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