节点文献

激光陀螺捷联惯性组合的标定方法研究

Research on the Calibration Method of Laser Gyro Strapdown Inertial Measurement Unit

【作者】 程源

【导师】 任顺清;

【作者基本信息】 哈尔滨工业大学 , 控制科学与工程, 2010, 硕士

【摘要】 由于激光陀螺具有精度高、可靠性好、成本低等优点,激光陀螺捷联惯导系统近年来已经成为惯性技术领域的一个重要研究方向。惯性测量组合是捷联惯导系统的核心部件,由加速度计和陀螺仪组成,用于敏感载体的加速度和姿态,因此惯性测量组合的精度将在很大程度上影响系统的导航精度。本文以激光陀螺捷联惯性组合为研究对象,主要分析了系统的误差模型、标定方法及测试设备误差对标定精度的影响。根据惯性器件的误差来源和工作环境,并考虑安装引起的误差,本文分析了加速度计、激光陀螺及惯性测量系统的误差模型,并根据导航过程中器件误差的传播特性推导了捷联惯导系统的误差方程。在此基础上,完成了加速度计和陀螺仪的测试,为误差补偿提供基准。研究了激光捷联惯性组合的分立标定方法,在双轴转台上完成了转台的对准及惯性组合的标定实验,设计并实现了加速度计组合的正十二面体20点实验,对实验结果进行分析和比较。通过坐标系变换和谐波分析的方法,分析了转台误差对加速度误差模型各项系数的影响程度,并通过仿真验证,从而为确定转台的精度指标提供了一定的依据。捷联惯导系统的系统级标定根据标定场所不同分为实验室标定和外场标定。在实验室静基座条件下可以利用速度误差进行系统级标定。本文建立了误差参数标定模型,分析了器件误差可辨识性,完成了标定位置的编排。从理论上分析了外场标定时系统状态的可观测性及收敛速度。

【Abstract】 Since laser gyro has the features of high precision, good reliability and low cost etc, laser gyro strapdown inertial navigation system has become an important development trend in recent years. Inertial measurement unit (IMU) which is the core of inertial navigation system (INS) is made up of laser gyros and accelerometers, sensitive to attitude and acceleration of carrier respectively. So the precision of IMU will affect the system navigation precision to a great extent. In this paper, research on error models, calibration methods and errors of the testing equipment on laser gyro strapdown inertial measurement unit are engaged.Firstly, based on the error sources and working environment of inertial instruments, the installing errors, the error model of the accelerometer, the laser gyro and the IMU are analyzed. The error equation of strapdown inertial navigation system is established according to the error propagation characteristics of inertial instrument when in navigation state. Accelerometers and laser gyros are calibrated for later error compensation.Then, methods of separate calibration of IMU are studied. Tests of turntable alignment, IMU calibration and dodecahedron 20 points plan are conducted on two-axis turntable, and all test results are compared and analyzed. Through methods of coordinate system transformation and harmonic analysis, the influence of turntable errors on accelerometers calibration precision is analyzed and verified by simulation. This can help to determine turntable precision specification more or less.Finally, according to calibration field, systematic calibration of IMU could be divided into the laboratory calibration and the outer field calibration. We can carry out systematic calibration through velocity errors under stationary based laboratory condition. In this paper the calibration mathematical model is established, identifiability of instruments errors is analyzed, one arrangement of calibration position is also designed. The observability and convergence rate of system states are analyzed in terms of theory.

节点文献中: