气动肌肉肘关节的滑模内环导纳控制设计

柔顺控制是共融机器人研究的重点。针对级联式气动肌肉肘关节动力学模型,建立了以滑模位置控制为内环、触力导纳控制为外环的控制结构;设计了带干扰观测器的滑模控制器（SMCDO）,证明SMCDO算法的收敛性;将环境等效为弹簧模型,设计了外环导纳控制器,并给出控制律。搭建实物测试平台,分别开展阈值力、力安全阈值测试以及碰撞测试,并分析了刚度系数对修正轨迹和接触力的影响。实验结果表明：关节柔顺性与刚度系数相关;SMCDO内环导纳控制精度优于无干扰观测器的滑模控制器内环导纳控制;所设计的控制算法稳定且有效。     

高速旋转弹的姿态控制系统设计

为了解决高速旋转弹姿态控制的难题,设计了一种基于滑动质量块姿态控制系统。从高速旋转弹姿态特点分析出发,建立了姿态动力学方程。根据时间尺度对其姿态回路进行了时标分离,将其分为内外两个回路,分别进行了控制系统设计。外环设计了含有跟踪误差及其积分函数的滑模控制器,内环则采用了依赖于状态的黎卡提方程(SDRE)的最优控制器。仿真结果表明,该控制系统能快速有效地实现对弹体姿态控制,可为实际工程应用提供必要的借鉴。     

基于高阶滑模观测器的微分滑模四旋翼无人机控制研究

针对四旋翼无人机鲁棒控制问题,提出了一种基于高阶滑模观测器的内环与外环控制器设计方法。首先,建立了四旋翼无人机模型的运动学与动力学方程,通过反馈线性技术将模型分解为线性部分与非线性部分。然后,在输入信号延迟的基础上推导了相应的滑模控制律,由分离定理分别设计了观测器与控制器,通过扰动识别减少需要观测的状态变量,继而减少了测量传感器,同时对观测器以及整个闭环系统稳定性进行了证明。仿真验证了所提出的控制算法在提高四旋翼无人机姿态控制系统精度以及鲁棒性方面的有效性。     

基于反求法的7055铝合金Johnson-Cook本构模型研究

为建立满足7055铝合金高速切削有限元模拟的本构模型,基于准静态拉伸实验和分离式霍普金森压杆(SHPB)动态冲击实验,采用变量分离和非线性拟合得出7055铝合金的初始Johnson-Cook(J-C)本构方程;结合高速铣削实验,基于Oxley切削模型的反求法对初始本构方程参数进行修正,建立7055航空用高强铝合金高温、大应变、高应变率材料本构模型。利用ABAQUS软件和获得的J-C本构方程建立7055高速切削有限元模型。有限元模拟的主切削力与实验结果相差较小,表明所建立的J-C本构方程能较好地应用于高速切削模拟。     

随动系统调试检测平台的设计与实现

随动系统调试检测平台,由积木式试验台架和检测分析装置组合而成。检测分析装置包括:电机测试系统、伺服控制系统调试分析计算机等检测器件组成。该平台对由伺服驱动器与高低/方位伺服电机构成的高低/方位速度控制环(内环)和由该速度控制环与随动控制箱、高低/方位传信仪构成的位置控制环(外环)进行仿真模拟试验,通过选择内外环调节参数使调炮的最大速度,最低速度,最大加速度,调炮精度,满足战技指标要求。     

陀螺加速度计静态误差模型研究

通过建立陀螺加速度计运动学和动力学方程,得出仪表感受线加速度的静态误差模型.提出在三轴转台上标定陀螺加速度计误差模型的新的试验方法.试验结果表明,采用机理分析和试验相结合的方法建立仪表的误差模型,提高了误差模型的精确度.     

机器鱼双闭环正弦形轨迹跟踪控制方法

为实现机器鱼位置和姿态的实时轨迹跟踪控制,通过将姿态控制作为内环、位置控制作为外环的方式设计双闭环控制算法。内环通过采用滑模控制器使得其收敛速度大于外环,保证闭环控制系统整体稳定性,通过李亚普诺夫稳定性定理证明机器鱼位置姿态双闭环控制系统具有渐近稳定性。仿真结果表明：该方法可有效控制机器鱼纵垂面轨迹的实时追踪;实验中机器鱼完成预设运动共耗时12 s,其轨迹最大误差和平均误差分别为0.078 m和 0.052 m,验证了双闭环算法在机器鱼轨迹跟踪控制中的有效性和高效性。     

某多管火箭炮支撑动力学分析

为降低火箭发射系统的静态载荷,对某多管火箭炮支撑进行动力学分析。以某车载多管火箭炮为例,以多刚体动力学和柔性动力学理论为基础,建立刚柔耦合多系统动力学方程。采用ANSYS和Recurdyn软件,通过ANSYS软件建立柔性化支撑架,导入Recurdyn建立的模型中,对千斤顶安装的3种位置进行发射动力学仿真分析。仿真结果表明:千斤顶放置在中部效果较好,该方法较真实地反映了实际情况。     

分离力作用点位置和风速大小对适配器分离影响研究

基于多体动力学理论,建立适配器分离动力学和运动学方程,运用MSC/Adams软件建立适配器分离仿真模型,对适配器分离力作用点不同位置、不同风速时适配器分离情况进行仿真和分析,得出不同情况下,适配器分离距离及适配器与弹体碰撞时的碰撞力大小,为分离方案的确定和适配器结构优化设计提供参考。     

四旋翼飞行器齿轮箱-支臂组件动态特性分析

为提高重载油动四旋翼飞行器的稳定性,研究齿轮箱-支臂组件动态特性并进行结构优化。利用Lanczos特征值求解器,进行齿轮箱-支臂组件模态分析,并通过试验采集组件中心位置的振动加速度值,优化芯轴长径比。采用Runge-Kutta法编程求解组件的动力学方程,揭示组件振动的规律和影响因素。研究结果表明：传动芯轴长径比超过20会产生较大弯曲振动,优化传动芯轴长径比（＜14）可有效改变其固有频率,避开激励频率及倍频;振动加速度随转速增大先增大、后减小,当激励频率与系统固有频率相等时达到最大;通过优化斜支撑的角度提高组件刚度可实现减振。     

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.     

Expert Systems Aimed at General Design of Projectiles

Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.     

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.