基于动态Allan方差的MEMS惯性测量单元的性能评价

摘要

为了对受温度等外界环境影响下的MEMS惯性测量单元进行性能评估，针对经典Allan方差法不能反映各惯性器件的时变特性的缺陷，提出了采用动态Allan方差（DAVAR）法对MEMS陀螺仪和加速度计进行随机误差项的辨识和时变特性分析。经典Allan方差法和DAVAR法的随机误差辨识结果和仿真结果表明：在随机误差辨识方面，DAVAR法相比经典Allan方差法的辨识结果更为准确；在变温环境下，DAVAR法的仿真结果还能够反映出惯性器件输出信号受温度变化等环境影响下的时变特性，DAVAR法能够对MEMS惯性测量单元进行准确评价。%In order to evaluate the performance of MEMS inertial measurement devices which are affected by external environment such as temperature, considering that the classical Allan variance method can not reflect the time-varying characteristics of each inertial device, this paper proposes dynamic Allan variance (DAVAR) method to recognize the random error term of MEMS gyroscopes and accelerometers, and analyze the time-varying characteristics of it. The stochastic error identification results and stimulation results by classic Allan variance and DAVAR methods show that, in respect of stochastic error identification, DAVAR method has more accurate recognition result compared to the classical Allan variance method;in a varying temperature environment, the simulation results of DAVAR method also reflects the time-varying characteristics of inertial devices’ output signals which are affected by temperature change or other environmental impact. Therefore, DAVAR method could evaluate the MEMS inertial measurement unit accurately.