MEMS陀螺标度因数误差分析及分段插值补偿

动态条件下,标度因数引起的误差是MEMS(Micro Electromechanical System)陀螺主要误差源之一.为了提高陀螺精度,基于内框驱动式硅MEMS陀螺误差机理,分析了标度因数常值误差、非线性误差以及不对称误差的物理起因,构建了标度因数误差数学模型,提出了对陀螺标度因数按照角速度大小分段插值的补偿方法,消除了转速引起的陀螺标度因数误差.试验结果表明:MEMS陀螺标度因数误差高达4053.2(°)/h(1 σ ),采用分段插值法补偿后陀螺误差减小到79.0(°)/h(1 σ ),补偿精度比一次拟合及分段法分别提高了15.4倍和7.5倍,验证了MEMS陀螺标度因数误差模型的正确性,证明了标度因数实时分段插值补偿方法的准确性和适用性.

Error analysis and integrated compensation of scale factor for MEMS gyroscope

In dynamic condition, scale factor error is one of the main errors for MEMS(micro electromechanical system)gyroscopes. For the sake of improving performance of the MEMS gyroscope, the physical origin of bias, nonlinear and asymmetry error of scale factor were analyzed. Based on the operational principle of MEMS gyroscope driven by the inner frame, mathematical error model of scale factor for MEMS gyroscope was designed. According to the angular velocity of gyroscope, the method to compensate scale factor was proposed so as to eliminate scale factor error caused by angular rate. The experimental results show that the scale factor original error of gyroscope is 4053.2(°)/h(1 σ ) and error compensated by the integrated compensation method is improved to 79.0(°)/h(1 σ ).Compared with the methods of least square and segmented compensation, the precision of gyroscope compensated by the integrated method is improved 15.4 and 7.5 times respectively. The accuracy of the theories model is verified and a theoretical foundation for future practical application is provided.