最优估计理论在虚拟仪器中的应用

On Exploring Better Exploitation of Virtual Instrument in ATE (Automatic Test Equipment)

结合 SIGMA5 0 GPS/INS组合导航系统自动测试设备 ( ATE)的研制 ,分析了工程上选择最优估计方法的原则和最优准则的使用条件 ;建立了基于卡尔曼滤波理论的被测系统数学模型 ;给出了最小二乘估计在量测数据预处理中的应用方法 ;指出了虚拟测试仪器与常规测试仪器的区别。应用实践证明软测量技术更能体现虚拟仪器的特征 ,数学模型、数据处理方法的改变不仅能提高虚拟仪器的性能指标 ,而且能提高测试速度、降低测试成本。

We deem that existing mathematical models and data processing methods in P.R.China have not exploited the virtual instrument as much as is possible. We aim to explore new mathematical model and data processing thinking to get higher performance out of virtual instrument, thus helping to boost test rate and reduce test cost when using ATE. We participated in the development of ATE for SIGMA50 GPS/INS integrated navigation system. Section 1 reviews briefly the difference between Virtual Instrument (VI) and common instrument. Fig.1 presents the schematic diagram of the components of SIGMA50 GPS/INS integrated navigation system. Section 2 explains testing requirements that have to be satisfied by the ATE we participated in developing. Sections 3 and 4 explain in detail how to estimate system errors of SIGMA50——velocity, attitude, position errors——and errors of inertial instrumen-ts——gyro drift and accelerometer bias. Sections 3 and 4 derive the mathematical model of SIGMA50 system, employ LSE (Least Squares Estimation) for preprocessing measured data, and propose Kalman filter algorithm for calculating system errors of SIGMA50 and errors of inertial instruments. Fig.2 gives some attitude test results of SIGMA50 which confirm preliminarily that our proposed method can indeed exploit VI in ATE better for testing SIGMA50 GPS/INS integrated navigation system.