【作者】 黄宗升；

【导师】 秦石乔；

【作者基本信息】 国防科学技术大学 ， 光学工程， 2007， 博士

【摘要】 寻北仪在军事领域有重要的应用价值。论文以高精度的激光陀螺寻北仪为研究目标,探讨了四频激光陀螺连续旋转、旋转定点采样和恒速偏频二频激光陀螺连续旋转、旋转定点采样等四种寻北仪方案,分别建立了其理论模型和误差模型,研制了相应的实验系统并进行了广泛而充分的实验研究。在深入的理论分析和实验研究的基础上,得到了恒速偏频二频激光陀螺旋转2位置采样方案是实现高精度激光陀螺寻北仪的主要途径这一重要结论。论文主要工作如下:1、探讨了激光陀螺寻北仪的多种实现方案,通过深入的理论分析和利用实测的激光陀螺数据进行仿真,得到了旋转方案优于捷联方案以及旋转定点采样方案2位置法精度最高的结论。2、提出了恒速偏频激光陀螺旋转2位置的寻北方案。该方案突出了二频激光陀螺随机游走系数小的特点,克服了机械抖动偏频对旋转测量机构的干扰,发挥了旋转定点采样2位置法的精度优势。所研制的恒速偏频激光陀螺寻北仪样机的300s寻北精度优于0.5′,且进一步提高精度的潜力较大。3、设计和研制了四种不同方案的寻北仪样机各一套,并进行了大量的实验,发现了连续旋转方案中轴晃动引起激光陀螺输出噪声变大的问题以及恒速偏频陀螺中安装骨架的热形变引起激光陀螺输出漂移的问题。4、实验研究验证了旋转定点采样方案优于连续旋转方案的结论,并找到了各方案的主要误差源。四频激光陀螺旋转定点采样方案的主要误差源是激光陀螺的随机游走。四频激光陀螺连续旋转方案的主要误差源是旋转轴的晃动,且转台的转速越高精度越低。恒速偏频激光陀螺旋转定点采样方案的主要误差源是零偏残差和采样噪声,零偏残差主要来源于机械结构,采样噪声主要来源于定位误差。恒速偏频激光陀螺连续旋转方案的主要误差源是测角误差和转动轴晃动,且转台的转速越高精度越低。5、采取有效的措施解决了几项对寻北精度影响较大的误差源。采用滑动2位置的寻北算法有效消除了激光陀螺零漂的影响;采用脉冲细分的方法有效降低了激光陀螺采样噪声的影响;采用陀螺放电管垂直安装的方法有效克服了地磁场对四频激光陀螺的影响;通过激光陀螺对光栅编码器的标校,提高了光栅编码器的定位精度。6、研究了旋转式激光陀螺寻北仪中激光陀螺比例因子的标定方法,并利用大理石平台和六面体对激光陀螺的比例因子进行了标定。提出了激光陀螺寻北仪系统零位的标定方法,并对所研制的寻北仪样机进行了标定。7、详细研究了扰动基座下的数据处理方法,将小波滤波应用于激光陀螺寻北仪,并利用统计分段加权的方法对小波滤波后的数据进行处理,可有效去除基座扰动的影响。更多还原

【Abstract】 North finder plays an important role in military applications. Aiming to high accuracy north finder based on ring laser gyro (RLG), this dissertation has discussed four north finding schemes as follows: continuous rotary scheme based on differential RLG, rotary multi-position sampling scheme based on differential RLG, continuous rotary scheme based on constant rate biased RLG, and rotary multi-position sampling scheme based on constant rate biased RLG. Theoretical models and error models of the four schemes have been established, and the corresponding experimental systems have been developed, then comprehensive experiments have been carried out. After detailed theoretical analysis and experimental investigation this dissertation comes to an important conclusion that the main approach to realize high accuracy RLG north finder is rotary two-position sampling scheme based on constant rate biased RLG. This dissertation has done the following work:1. Multiple north finding schemes have been studied. By detailed theoretical analysis and simulation with RLG data, this dissertation gets the following conclusions: the rotary scheme is better than the strapdown scheme, and rotary two-position sampling scheme achieves the highest accuracy.2. Rotary two-position sampling scheme based on constant rate biased RLG has been proposed. This scheme can take full advantage of both the small random walk feature of RLG and high accuracy of two-position north finding algorithm. Meanwhile, it can overcome the mechanical disturbance in mechanically dithered RLG. The north finding accuracy of the prototype based on this scheme is better than 0.5’ within 300s, with potentialities to be improved.3. Four different north finder prototypes have been designed and developed. Through a series of experiments, we find the following phenomena: the RLG output noise turns larger due to the swash of spin axis in continuous rotary scheme, and the RLG output varies due to the thermal deformation of the RLG support in constant rate biased RLG.4. The conclusion that rotary multi-position sampling scheme is better than continuous rotary scheme is proved by experiments, and the main error sources of each scheme have been found. For rotary multi-position sampling scheme based on differential RLG, random walk of RLG is the main error. For continuous rotary scheme based on differential RLG, the swash of spin axis is the main error, and the north finding accuracy becomes lower when the platform rotates faster. For rotary multi-position sampling scheme based on constant rate biased RLG, the following two errors are most important: bias residual deviation of RLG caused by mechanical factor and sampling noise of RLG caused by positioning error. For continuous rotary scheme based on constant rate biased RLG, the angular measurement error and the swash of spin axis are the main errors, and the north finding accuracy becomes lower when the platform rotates faster.5. Effective measures have been taken to reduce the north finding error. The sliding two-position north finding algorithm can reduce the effect of RLG drift. The pulse subdivision technique can reduce the sampling noise of RLG. Mounting the differential RLG with its discharge tube perpendicular to the rotary platform can reduce the earth’s magnetic effect. Calibration by RLG can reduce the error of optical angular encoder.6. The calibration method of scale factor of RLG in rotary north finder has been studied, and scale factor of RLG has been calibrated using a marble platform and a hexahedron. The calibration method of system offset of north finder based on RLG has been proposed, and the system offset of the prototype has been calibrated.7. The data processing method of north finder on disturbing base has been studied. Grouping weighting method following wavelet filtering efficiently reduces the effect of base disturbance.更多还原