Filtering method and device for inertial measurement unit

Abstract

The invention provides a filtering method and device for an IMU (inertial measurement unit), and the method comprises the steps: carrying out the low-order wavelet denoising processing of an output signal of a to-be-processed sensor; detecting the state of the sensor, and filtering low-frequency noise in a wavelet denoising result through a mean value compensation method when the to-be-processed sensor and a coherent shaft sensor are in a static state; carrying out the Kalman filtering of the wavelet denoising result when the to-be-processed sensor is in a static state and the coherent shaft sensor is in a dynamic state, thereby achieving the inhibiting of the low-frequency noise in the wavelet denoising result. The method employs the wavelet denoising method, so the method is small in calculation burden. Moreover, the method eliminates the impact on the sensor in the static state from the low-frequency noise through the mean value compensation method, and improves the static performances. The method achieves the inhibition of the low-frequency noise through the Kalman filtering method when the to-be-processed sensor is in the static state and the coherent shaft sensor is in the dynamic state, and improves the dynamic performances of the filtering of the IMU.

Description

Technical field [0001] The invention belongs to the field of automatic control, and particularly relates to a filtering method and device of an IMU (Inertial Measurement Unit). Background technique [0002] The IMU contains three single-axis acceleration sensors and three single-axis angular velocity sensors. Three single-axis acceleration sensors are installed orthogonally to measure acceleration signals in each axis direction; three single-axis angular velocity sensors are installed orthogonally to measure angular velocity signals in each axis direction. [0003] MEMS (Micro-Electro-Mechanical Systems, Micro-Electro-Mechanical Systems) IMU is being used more and more widely in the field of navigation. Limited by the manufacturing process and accuracy level of the MEMS IMU, the random noise of the output signal is relatively large. Therefore, the MEMS IMU must be filtered to improve the accuracy of the output signal of the MEMS IMU. [0004] In the prior art, a high-order wavelet ...

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Problems solved by technology

[0005] In view of this, the object of the present invention is to provide an IMU filtering method and device to solve the time-consuming technical problem of the filtering process in the prior art

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