Research on feasibility of missile attitude control based on laser gyroscope

According to the disadvantages of traditional mechanical gyro inertial measurement unit('IMU') for steering system not being available for missile attitude control, a concept based on laser gyro IMU is proposed to realize navigation & positioning and attitude control. The concept will save three single-axis rate gyros compared with traditional missile attitude control system, and is available both for strapdown and platform inertial navigation systems. Firstly, this article analyzes the selection requirements of sensitive device for missile attitude control system, and then analyzes the feasibility of missile attitude control based on laser gyro theoretically, on this basis, from four aspects of error characteristics, anti-vibration characteristics, temperature characteristics and dynamic characteristics, validate the feasibility of the concept practically. Secondly according to the strict requirements of dynamic characteristics on attitude control system, a special design is made for gyro signal filtering used for attitude control. By changing the traditional high order FIR filter to adaptive filter and low order FIR filter, laser gyro's signal phase delay is reduced. The delay time of theoretical design is 1.5 ms. Lastly, this design is validated through an angle vibration test, and test curve indicates that the dynamic characteristics of laser gyro completely meets the requirements of the attitude control system, and the maximum delay time is 1.6144 ms, which satisfies with the attitude update rate of 2 ms per frame. This concept can simplify the missile guidance system design, at the same time, it does not reduce missile guidance accuracy, and also provides reference for the broadening of the application of laser gyro.

Suppression of the G-sensitive drift of laser gyro in dual-axis rotational inertial navigation system

The dual-axis rotational inertial navigation system(INS)with dithered ring laser gyro(DRLG)is widely used in high precision navigation.The major inertial sensor errors such as drift errors of gyro and accelerometer can be averaged out,but the G-sensitive drifts of laser gyro cannot be averaged out by indexing.A 16-position rotational simulation experiment proves the G-sensitive drift will affect the long-term navigation error for the rotational INS quantitatively.The vibration coupling and asymmetric structure of the DRLG are the main errors.A new dithered mechanism and optimized DRLG is designed.The validity and efficiency of the optimized design are conformed by 1 g sinusoidal vibration experiments.An optimized inertial measurement unit(IMU)is formulated and measured experimentally.Laboratory and vehicle experimental results show that the divergence speed of longitude errors can be effectively slowed down in the optimized IMU.In long term independent navigation,the position accuracy of dual-axis rotational INS is improved close to 50%,and the G-sensitive drifts of laser gyro in the optimized IMU are less than 0.0002°/h.These results have important theoretical significance and practical value for improving the structural dynamic characteristics of DRLG INS,especially the highprecision inertial system.

Dynamic model and simulation of aseismatic system about laser gyro strapdown inertial measure assembly based on MSTMM

The precision of the laser gyro used in tactical missiles is poor because of dithering frequency,actuating by vibration,shock and overload in dynamical environment.This paper introduces the transfer matrix method of the multibody system（MSTMM）,establishes the dynamic model of the laser gyro strapdown inertial measure assembly aseismatic system,and analyzes the precision affected by dithering of the laser gyro and shocking of the tactical missile.And the dynamic response of the laser gyro strapdown inertial measure assembly aseismatic system is obtained by simulating the multibody system model.The simulation result indicates a theoretical idea to design the vibration isolation for the laser gyro strapdown inertial measure assembly.

Polarization properties in a prism laser gyro with mechanical dither bias

Theoretical analysis and experimental research on the polarization properties of output light in gyro are carried out to investigate the phenomenon that the amplitude of an output voltage signal is modulated by dither bias in laser gyros consisting of totally reflecting prisms. Taking the effect of prism stress birefringence into account, an analytical formula of the output light intensity in the gyro and the relationship between the polarization parameter and the amplitude modulation of the output signal are obtained and discussed. For the first time, the polarized power value of the output light is adopted as a basis to estimate the output signal amplitude fading extent of laser gyros. Experimental results demonstrate that when the value of polarized power of output light is below 25.5% of that in ideal static case, the standard error is over 0.0337 dBm, and the displacement extent of the prism is higher than 53% of the radius of the beam waist in the gyro cavity, the amplitude modulation extent of gyro output signal can reach up to 16%, which badly influences the measurement accuracy of the laser gyro. Using this polarized power detecting measurement method can repair the gyro immediately during its fabrication process, improve the testing and production efficiency and shorten the product development cycle.

Signal processing circuit of laser gyro based on FPGA and DSP

This is a paper about laser gyro sign a l processing circuit which is designed based on field-programmable gate array(FPGA) and digital signal processor(DSP).Through a pre-amplifier circuit,FPGA and DSP,a weak current signal is converted and transferred,then sent to the computer to display the final results.Through the laser gyro performance te sting,the obtained results coincide with those of the existing methods.Thus th e d esigned circuit realizes the function of laser gyro signal processing.

New interpretation of laser gyro drifts

Discuss and develop some contents which are relevant to the IEEE Std 647TM-2006 in this paper. The IEEE Std only involves Allan variance, and decomposes it into five primary noise terms, in which, however, the noise nature of the so called "rate random walk noise" and the "rate ramp" is doubted by the IEEE Std editors. Here we use a mathematical identity to entirely affirm the first query and partially the second query as mentioned above. Besides, we argue that only the classical variance can be used in navigation, not the Allan variance. In order to seek the true nature of all drift terms in the variance, we adopt our original work that represents the noises as damped oscillations, to obtain the power spectral density (PSD) of the noises which is then transformed back into time domain. When the damped time constant is much longer than the sampling interval, the re-sulting slow variation term may be expanded into three terms: ordinary bias instability, rate random walk, and rate ramp. Therefore, these "noise terms" are not independent, and they are more of deterministic errors than random noises, and can be explained quantitatively. The resulting fast variation drift may be expanded into two terms. The first term is the same as angle random noise, while the second term adds to the true quantization noise term to form a new combined term called "quantiza-tion noise term". As the result of our research, not only the IEEE Std editors’ suspicions above are answered completely, but a new theory to analyze the laser gyro drifts is also presented, with several supporting examples to explain and verify the theory.

基于激光陀螺测角仪的角度计量动态特性分析

为了使动态角度测量结果可靠、可信,在使用激光陀螺测角仪进行动态角度测量前,需要对其动态特性进行分析。首先,通过同步触发装置将激光陀螺测角仪分布与转台和激光干涉仪分别同步触发;然后,使转台模拟出脉冲响应运动、阶跃响应运动和正弦运动;最后,比较分析在不同运动过程中激光陀螺测角仪与转台的圆光栅和激光干涉仪的输出数据。结果表明,激光陀螺测角仪具有良好的动态特性,且在不同频率下激光陀螺测角仪的动态测角精度在0.6″左右,为激光陀螺测角仪进行动态角度测量结果的可靠性提供了保证。

Algorithm implementation of high-speed laser g yro signal demodulation filter

Based on the characteristics of field-programmable gate array(FPGA) such as multi-task,high-speed,parallelity,etc,a filtering algorithm is presented to filter the output signal of laser gyr o with high-speed and high accuracy.The filter is composed of basic logic cell s,multipliers an d memory inside FPGA.By using an multiplication decomposition method and design ing reliable time-sequence,the filter is realized,which is easy to be transpl anted and of low cost.Furthermore,all the signal demodulation algorithms of t he laser gyr oscope can be integrated in only one FPGA,which reduces the cost and complexity of the system.

光学陀螺背向散射问题综述(特邀)

光学陀螺作为光电惯性导航系统的核心器件,在众多领域发挥着举足轻重的作用。随着科学技术的不断进步,传统的激光陀螺、轻质化的光纤陀螺以及集成化的微光陀螺齐头并进、蓬勃发展,但无论是哪一种陀螺样式,在性能优化的过程之中都不可避免地需要考虑背向散射的问题。背向散射是光学陀螺中的一种噪声源,其会带来陀螺的输出偏置或闭锁效应,从而影响其性能。为了更好地理解光学陀螺中的背向散射机制,首先从半经典理论下的自洽方程组出发讨论背向散射的基本原理,而后依照光学陀螺的发展脉络,分析各种光学陀螺的背向散射分析方法、测量手段以及抑制方法,最后对目前光学陀螺中有关背向散射亟待解决的问题进行总结并展望。

无依托瞄准技术在运载火箭基准确立上应用的研究

针对大型运载火箭无人值守瞄准的需求,提出一种基于激光捷联惯组与瞄准仪相结合的无依托瞄准方法,通过激光惯组自主寻北获得北向基准,再测量出箭上惯性单元棱镜法线与返回光束的准直偏差角,将数据进行合成、解算,最终获得箭上惯组棱镜的初始方位。无依托瞄准技术具有组成简单、自动化程度高、操作流程简化、精度指标可靠的特点,可以提供不大于2’的瞄准综合误差,技术成果满足中国航天发射任务的应用需求,可供未来大型运载火箭瞄准方式参考。

全反射棱镜式激光陀螺标度因数补偿技术

针对全反射棱镜式激光陀螺标度因数随温度周期性变化的现象,根据矩阵光学方法研究了稳频状态下温度变化对环形激光面积的影响,获得了全反射棱镜式激光陀螺标度因数与稳频电压的关系,并得出光束偏移是引起标度因数随温度周期性变化的原因。根据标度因数与稳频电压的关系,建立了全反射棱镜式激光陀螺标度因数补偿模型,通过实验对比了补偿前后标度因数的非线性度。结果表明,根据该补偿模型对全反射棱镜式激光陀螺标度因数进行补偿,标度因数非线性度提高了一个数量级以上,对提高全反射棱镜式激光陀螺的性能具有一定的参考价值。

激光陀螺表面多层膜微结构表征与分析

本文针对激光陀螺长期稳定性技术研制要求,通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、扫描透射电镜(STEM)、聚焦离子束刻蚀(FIB)、X射线光电子能谱(XPS)以及X射线能量散射谱(EDX)等微观结构和组分表征技术,对激光陀螺反射镜的微观结构和组分进行表征,研究反射镜在不同镀制工艺条件及高低温等外部工作条件下,反射镜膜层界面、膜-基界面以及膜层本身微结构特性的变化规律,建立反射镜微结构特性和不同变化之间的映射关系。本研究结果为激光陀螺表面多层膜的结构表征提供坚实的实验参考和理论依据。

基于ZYNQ的激光陀螺寻北仪的设计

在现代化战争中的武器系统以及民用勘测领域中,寻北技术发挥着无与伦比的作用。基于此背景,该文设计了一种基于ZYNQ的光纤陀螺寻北仪。该系统由XB185D单轴闭环光纤陀螺通过串行422通信接口将数据发送给ZYNQ,并通过AD模块AD7693对两路石英加速度计进行数据采集,利用温度传感器DS18B20进行温度数据采集。以XC7Z020为逻辑控制核心,通过四位置寻北算法解析北向角度,通过串口总线将结果发送到上位机上。经测试表明,该系统稳定可靠,能准确地定位北向,其误差范围在0.3°内。

基于激光陀螺测角仪的转台角定位误差多点测量与补偿方法

目的:提高激光陀螺测角仪测量转台的角位置精度,实现转台的全圆周内任意角度测量与补偿。方法:采用全新测量方式,利用环形激光原理实现转台任意角度高精度测量。首先提出激光陀螺测角仪进行多位置平均的偏置标定方法;然后采用激光陀螺测角仪进行全圆周小角度范围测量,并得到角位置误差函数;最后以自准直仪数据为真值作比对。结果:激光陀螺测角仪测试转台的精度由0.6″提高到了0.3″,并且实现转台在全圆周范围内测角精度为0.3″。结论:多位置平均的偏置标定方法能够有效地提高激光陀螺测角仪的测量精度,并且可以对转台进行全圆周任意角度的测量。

激光陀螺单轴旋转惯性导航系统

高精度的惯性导航系统是提高舰船综合作战性能的基础。为了提高惯性导航系统的精度,采用单轴旋转惯性测量组件的方法,研制了激光陀螺单轴旋转惯性导航系统。介绍了系统的硬件组成,主要包括系统基本结构,惯性器件的主要技术参数和导航计算机的组成。描述了系统的多位置初始对准方式和温度补偿方案。对该系统进行了长时间静态导航实验和跑车实验,实验结果表明:四次长时间静态导航实验峰值定位误差5d优于1nm,10d优于2nm;两次跑车实验峰值定位误差77h优于1.4nm、15d优于2.5nm。

小波域中值滤波在激光陀螺信号处理中的应用

各种随机噪声是导致激光陀螺产生误差的主要因素,且其性质特殊,很难用传统的滤波方法去除。为了减小激光陀螺的随机误差,提高测量精度,提出了小波域的中值滤波器滤波方法,对激光陀螺零漂数据进行了滤波,并采用Allan方差法对滤波效果进行了定量分析。结果表明,此方法的滤波效果优于中值滤波和小波软阈值滤波效果,能有效地减小激光陀螺零漂信号中的角度随机游走、角速度随机游走、速率斜坡、零偏不稳定性和量化噪声,提高激光陀螺零漂输出的稳定性。

基于姿态匹配的船体形变测量方法

针对激光陀螺船体形变测量系统,提出了一种新的基于姿态匹配的形变测量解算方法。该方法不同于以角速度差作为观测量的惯性测量匹配法,而是基于两套激光陀螺系统的姿态信息。确立了新的形变测量滤波观测量,并建立线性量测方程。两套激光陀螺系统直接利用激光陀螺输出的角增量数据相对于惯性空间进行姿态更新,惯性坐标系取为各自初始时刻的载体坐标系,完全回避了系统初始对准问题,且充分利用了激光陀螺角度测量精度高的特点。仿真结果表明,该方法能够有效实现船体形变的高频精确测量,仿真测量精度优于15″,为激光陀螺船体形变测量技术进入工程应用打下了基础。

激光陀螺锁区特性的研究

从理论和试验两个方面,研究了四边形腔环行激光陀螺的锁区特性·利用环行腔中背向散射光束具有相干性,导出了环行谐振腔综合背向散射与反射镜、反射镜之间的相对位置的关系·在有两个位移反射镜的四边形谐振腔中,理论上得到了综合背向散射系数与谐振腔腔长具有双波长周期·利用综合背向光强实验及锁区与陀螺工作模数实验分别验证了理论的正确性·试验证实散射光的强度与谐振腔的工作模数存在双模周期性,综合背向散射系数大,陀螺锁区大,反之亦然·

环形激光陀螺的最新发展

环形激光陀螺是当前高精度捷联惯导系统中最重要的设备之一,它在军用领域和商用领域获得了广泛的应用。近几年,和环形激光陀螺相关的进展主要可以概况为三个方面:激光陀螺研制技术的进步;对激光陀螺系统研究方法的深入和激光陀螺应用领域的扩展。激光陀螺发展的最新动态,对国内激光陀螺工业有重要的参考价值,将有助于提高我国环形激光陀螺技术水平。

激光陀螺SINS/GPS组合导航车载试验系统

SINS GPS组合导航系统已经应用于许多不同的领域。介绍一种已经进入试验阶段的低成本激光陀螺SINS GPS组合导航系统。根据系统的硬件结构,设计实现了与实际系统相匹配的组合导航滤波器,根据车载试验的结果,着重分析了系统车载试验中不同导航模式对系统性能的影响,最后给出了一些有益的结论。