捷联式微惯性导航系统的标定方法

设计了微惯性导航单元（MINU）结构。采用翻滚法和转台法，建立数学模型，分别标定加速度计和陀螺的零位偏差、标度因子及安装角误差。提出一种基于虚拟噪声的现场最优标定方法，运用卡尔曼滤波技术估计并补偿加速度计和陀螺零偏。实验室静态实验和车载实验结果均证明了上述方法的正确性和可行性，并且快速、易于实现，能有效提高导航精度，适用于短时间、低中精度导航系统。     

电容型力平衡硅微加速度计的建模与系统设计

本文建立了硅微机械结构电容型静电力平衡方案加速度计的数学模型，并利用此模型讨论了系统闭环回路控制方案设计中的一些特殊问题，接口电路采用开关电容型电路，并给出接口电路图，最后，给出一实际设计实例。     

用于末敏弹稳态扫描参数测量的微惯性测量单元的误差标定

对用于末敏弹稳态扫描阶段参数测量的微惯性测量单元提出了一种标定方法。由于末敏弹在稳态扫描阶段的运动特点,采用的陀螺的量程往往比较大,因此需要对其建立合适的误差模型。文中首先对微惯性测量单元中的陀螺和加速度计分别建立了适当的误差模型。之后,进行了转台速率实验和转台位置实验。应用线性拟合和最小二乘法对速率实验和位置实验的数据进行解算,得到了所建误差模型中的参数。最后将标定过的微惯性测量用于仿真投弹实验。实验结果表明文中采用的误差标定方法是合理的。     

对惯性导航系统仪器误差的研究

本文研究陀螺仪漂移ω和加速度计测量误差△a的不确定分量对惯导系统速度误差和位置误差的影响,详细分析了ω和△a的“隐形”分量、“显形”分量、线性分量和谐波分量引起的惯导系统误差,并给出了计算这些误差的表达式。     

一种激光陀螺捷联惯性导航系统级标定方法

为优化激光捷联惯性导航在卧式三轴转台上的系统级标定方案,设计了卧式三轴转台外环轴整周旋转对惯性测量单元（IMU）误差参数的激励方法。基于捷联惯性导航的误差方程,阐述了速度误差与IMU误差参数间的关系,从而建立IMU系统级标定模型。该模型具有加速度计误差参数仅反应在观测量北向分量、陀螺误差参数仅反应在观测量东向分量的特点,消除了加速度计和陀螺误差参数标定误差的相互影响。根据准D最优准则,设计了正二十面体12点计划的双轴位置单轴速率翻滚法,利用最小二乘法辨识出IMU的24项误差参数。通过给加速度计和陀螺加入不同测量噪声,对IMU标定模型进行仿真,结果表明该方法可抑制加速度计和陀螺的测量噪声对标定结果的影响。     

加速度计的动态特性对无陀螺微惯性测量组合性能影响的研究

本文以压阻式加速度计为例,探讨了其动态特性对无陀螺微惯性测量组合的影响.首先,建立了9个加速度计的无陀螺微惯性测量组合模型,并推导了该模型的导航方程,然后根据加速度计的动态特性改进了其导航方程,最后进行了仿真验证.从仿真结果可以看出,对于相同的加速度计,输入信号的动态特性越强,惯性组合的误差越大.因而选用动态特性好的加速度计有助于提高无陀螺微惯性测量组合的性能.本文为无陀螺微惯性测量组合走向实用化,提供了理论依据.     

微震动测试系统抗噪声干扰技术研究

详细分析了微震动测试系统的各种噪声源。通过建立固有噪声的电路模型、计算系统的噪声系数、分析噪声系数特点，设计了与压阻式震动传感器噪声匹配的低噪声前置放大器。在分析干扰噪声的特点的基础上，设计了防电磁干扰的屏蔽系统。     

石英挠性加速度计性能分析平台的构建

通过对某型加速度计测试系统现状的分析,设计了基于GPIB总线技术的加速度计测试系统,根据测试原理确定了数据采集系统的组成,根据加速度计的输出与其静态模型方程系数的关系,构建了加速度计性能分析平台,论述了测试数据的采集与处理方法、并利用Access数据库实现了数据的存储与调用。最后,利用MATLAB工具,建立了加速度计性能参数模型,并做出了相应的预测与差值估计。     

旋转弹导航系统研究

旋转弹自转角速度大，由陀螺仪和加速度计组成的传统导航系统难以应用，提出用微小型加速度计构成无陀螺微惯性测量单元GFMIMU(Gyroscope-Free Micro Inertial Measurement U-nit)为旋转弹提供完整的导航信息。根据无陀螺的测量原理，充分利用多个加速度计的冗余输出信息构建自滤波系统，抑制GFMIMU角速度误差的快速发散。为克服GFMIMU长时间工作姿态角误差的积累，采用磁强计与其进行组合导航；从解算精度与实时性考虑，基于四元数描述建立了该组合寻航系统的状态方程和观测方程，并采用二阶插值滤波器进行信息融合。最后，对所设计的组合导航系统进行系统仿真，仿真结果验证了该系统设计方案的可行性。     

弹载MEMS加速度计自适应滤波算法

为了降低导弹过载的测量噪声,提出一种弹载微机电系统(micro electro mechanical system,MEMS)加速度计自适应滤波器的设计方法.该方法根据过载变化来设定条件阈值,对滤波系数进行自适应调节,提高了导弹过载测量精度.仿真结果表明:该滤波算法可有效将加速度计测量噪声标准差从0.020 6 m/s2降低到0.006 1m/s2,较好地兼顾了加速度计在低过载下数据平滑性和高过载下数据灵敏性的要求.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design of Non-fragile Satisfactory Estimator for Linear Continuous Perturbed Stochastic Systems

The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality （LMI） approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example.     

An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

The improved scene-based adaptive nonuniformity correction （NUC） algorithms using a neural network （NNT） approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays （IRFPA） nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij （ n ） is proposed as an alternative value of desired network output of neuron Xij （ n ）, denoted as Tij （ n ）, which is the local spatial average of Xij （ n ） in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences （several hundred frames） subjected to the dense impulse noises with a number of dead or saturated pixels.     

Piecewise Filter of Infrared Image Based on Moment Theory

The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter （PMF） is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.     

Bistatic Sonar Localization Based on Best Linear Unbiased Estimation

A best linear unbiased estimation （BLUE） algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision （GDOP） in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method.     

Research on Gear-broken Fault Diagnosis in a Tank Gearbox

A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.