基于曲线拟合的光纤陀螺非线性误差补偿方法研究

发布时间：2018-04-02 07:18

本文选题：光纤陀螺　切入点：标度因数　出处：《哈尔滨工程大学》2014年硕士论文

【摘要】：捷联惯性导航系统是一个由多种惯性测量元件和测量单元组成的复杂系统。在多种测量装置中陀螺仪占有举足轻重的地位。现代捷联惯导系统中多采用光纤陀螺作为导航系统陀螺仪。其具备体积小、精度高、无转动部件、抗冲击和抗干扰能力强、动态测量范围大的特点,不仅仅应用在导航系统中,而且在航空航天、精密仪器仪表、国防工业设备、兵器工业制造等领域都发挥着重要的作用。光纤陀螺标度因数的优劣对其输出精度起着决定性的影响,而在对实际光纤陀螺性能进行测试的过程中,发现标度因数在其动态测量范围内并不是完全呈现线性性质。在其中某些角速率区间内,标度因数的非线性突变将导致标度因数误差明显增大,从而对导航精度产生不良影响。根据上述问题,本篇文章进行了以下几个方面的研究:本文首先介绍了光纤陀螺的基本工作原理以及两种类型的光纤陀螺的基本结构,并且分别阐述了光纤陀螺中信号检测与相位调制的方法。说明了针对全数字闭环结构的光纤陀螺调制的具体实现方法。其次,根据光纤陀螺的输入、输出及误差之间的关系,确定了光纤陀螺的数学模型,并且依据上述模型详细介绍了光纤陀螺标度因数以及其非线性度的测试步骤和计算过程。介绍了光纤陀螺捷联惯导系统的基本结构和原理,根据捷联惯导系统的误差方程建立了标度因数误差与载体运动角速率之间的关系式,并依据此关系进一步推到出标度因数误差对捷联惯导系统输出参数精度的影响,并利用Matlab软件进行仿真分析验证。接着分析了造成标度因数误差的相关因素,并提出一种在确定多项式阶数的前提下数据点自适应分段的拟合方法,进而对光纤陀螺多角速率测试实验中的数据进行分段拟合,拟合得到分段标度因数。利用模拟海上摇摆试验对拟合得到的分段标度因数应用效果进行验证。结果表明选用分段标度因数的导航参数解算精度要优于传统单一标度因数情况下的导航参数解算精度。而且该方法在工程实践中容易实现,是一种简单、高效提高标度因数稳定性的方法。最后简单介绍了可编程逻辑器件的基本概念,并结合其中一种可编程逻辑器件FPGA设计制作了一块系统电路板,该设计中选用了 Altera公司CycloneIV系列中的EP4CE6型号芯片。在FPGA芯片内设计了一系列软件功能模块实现数据的输入输出和分段处理,而且利用逻辑分析工具对设计模块进行了测试验证。
[Abstract]:Strapdown inertial navigation system is a complex system composed of a variety of inertial measuring elements and measuring units. Gyroscope plays an important role in a variety of measuring devices. Fiber optic gyroscope is often used in modern strapdown inertial navigation system. As a navigation system gyroscope. It has a small size, High precision, no rotating parts, strong anti-shock and anti-jamming ability, wide range of dynamic measurement, not only used in navigation systems, but also in aerospace, precision instrumentation, national defense industry equipment, The scale factor of fiber optic gyroscope (fog) plays a decisive role in the output accuracy, and in the process of testing the performance of the fiber optic gyroscope (fog), It is found that the scaling factor is not completely linear in its dynamic measurement range. In some angular rate ranges, the nonlinear mutation of the scale factor will result in a marked increase in the scaling factor error. According to the above problems, this paper studies the following aspects: firstly, this paper introduces the basic working principle of fiber optic gyroscope and the basic structure of two kinds of fiber optic gyroscope. The methods of signal detection and phase modulation in fiber optic gyroscope (fog) are expounded respectively. The realization method of fiber optic gyro modulation based on digital closed loop structure is explained. Secondly, according to the relationship between input, output and error of fiber optic gyroscope, The mathematical model of fiber optic gyroscope (fog) is determined, and the scale factor of fog, the testing steps and calculation process of its nonlinearity are introduced in detail, and the basic structure and principle of fog strapdown inertial navigation system are introduced. Based on the error equation of strapdown inertial navigation system, the relation between scaling factor error and carrier motion angle rate is established, and the influence of scaling factor error on the precision of strapdown inertial navigation system output parameters is further deduced. Then the related factors of scale factor error are analyzed, and a fitting method of adaptive segmentation of data points under the premise of determining polynomial order is put forward. Then, the data of fiber optic gyroscope (fog) polygonal rate test are fitted in sections. The segmental scaling factor was obtained by fitting. The application effect of segmental scaling factor was verified by simulated sea swinging test. The result shows that the accuracy of navigation parameters with piecewise scaling factor is superior to that of traditional single one. In the case of scale factor, the calculation accuracy of navigation parameters is obtained, and the method is easy to be realized in engineering practice. It is a simple and efficient method to improve the stability of scale factor. At last, the basic concept of programmable logic device is briefly introduced, and a system circuit board is designed and fabricated with one programmable logic device (FPGA). In this design, the EP4CE6 chip of CycloneIV series of Altera company is selected. A series of software function modules are designed in FPGA chip to realize the input, output and segment processing of data, and the design module is tested and verified by logic analysis tool.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96

【参考文献】