Chang Longkang, Cao Huiliang, Shen Chong
Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China.
Micromachines (Basel). 2020 Jun 11;11(6):586. doi: 10.3390/mi11060586.
For the sake of decreasing the effects of noise and temperature error on the measurement accuracy of micro-electro-mechanical system (MEMS) gyroscopes, a denoising and temperature drift compensation parallel model method based on wavelet transform and forward linear prediction (WFLP) and support vector regression based on the cuckoo search algorithm (CS-SVR) is proposed in this paper. First, variational mode decomposition (VMD) is proposed in this paper, which is aimed at dividing the output signal of the gyroscope into intrinsic mode functions (IMFs); then, the IMFs are classified into three features-drift, mixed, and pure noise features-by the sample entropy (SE) value. Second, a wavelet transform and forward linear prediction (WFLP) are combined to remove the noise from the mixed features. Meanwhile, the drift feature is compensated by support vector regression based on the cuckoo search algorithm (CS-SVR). Finally, through reconstruction, the final signal is obtained. Experimental results demonstrate that the VMD-SE-WFLP-CS-SVR method proposed in this paper can decrease noise and compensate the temperature error effectively (angular random walking value is optimized from 1.667°/√h to 0.0667°/√h and the bias stability is reduced from 30°/h to 4°/h). In terms of denoising, the performance of the WFLP algorithm is superior to the wavelet threshold and FLP, as it combines their advantages; furthermore, in terms of temperature compensation, the proposed CS-SVR algorithm uses the cuckoo search algorithm to find the optimal parameters of SVR, improving the accuracy of the model.
为了降低噪声和温度误差对微机电系统(MEMS)陀螺仪测量精度的影响,本文提出了一种基于小波变换和前向线性预测(WFLP)以及基于布谷鸟搜索算法的支持向量回归(CS - SVR)的去噪和温度漂移补偿并行模型方法。首先,本文提出了变分模态分解(VMD),旨在将陀螺仪的输出信号分解为固有模态函数(IMF);然后,通过样本熵(SE)值将IMF分为三种特征——漂移、混合和纯噪声特征。其次,将小波变换和前向线性预测(WFLP)相结合以去除混合特征中的噪声。同时,利用基于布谷鸟搜索算法的支持向量回归(CS - SVR)对漂移特征进行补偿。最后,通过重构得到最终信号。实验结果表明,本文提出的VMD - SE - WFLP - CS - SVR方法能够有效降低噪声并补偿温度误差(角随机游走值从1.667°/√h优化到0.0667°/√h,偏置稳定性从30°/h降低到4°/h)。在去噪方面,WFLP算法结合了小波阈值和FLP的优点,性能优于它们;此外,在温度补偿方面,所提出的CS - SVR算法利用布谷鸟搜索算法寻找SVR的最优参数,提高了模型的精度。