High Precision Attitude-Rate Measurement of Magnetically Suspended Control and Sensing Gyroscope Using Variational Mode Decomposition and Wavelet Transform

A high-precision attitude-rate measurement of Magnetically Suspended Control & Sensing Gyroscope (MSCSG) using Variational Mode Decomposition (VMD) and Wavelet Transform (WT) is proposed in this paper, to aim at the influence of tilt current and tilt signal noise of MSCSG on attitude angular-rate measurement accuracy of spacecraft. Firstly, the sensitive model based on Lorentz torquer force is established, and the composition of rotor tilt signal is analyzed. The basic principle of modal decomposition of MSCSG tilt signal by VMD is introduced. A denoising method of MSCSG tilt signal based on improved VMD & WT is proposed. The number of mode decomposition is determined to improve VMD, by analyzing the frequency domain characteristics of tilt signal. WT is used to denoise the irrelevant mode obtained from VMD, and the signal is reconstructed by combining the denoising result and the relevant mode. Finally, simulation and experiments show that the proposed method has a good denoising effect on the tilt signal of MSCSG, and the angular-rate measurement accuracy of MSCSG can be improved by 16.2%.