无人机飞行控制PID参数的模糊自整定技术研究

现今，无人机在军事和民用上都有重要的应用价值．它要完成自主飞行，需要飞机的控制系统具有良好的控制特性．本文中首先介绍了PID参数自整定方法，然后针对无人机俯仰姿态的控制律设计了一种模糊PID飞行控制器，并对这种PID控制器的控制特点及参数设计规则等进行描述．仿真结果表明，这种模糊自整定PID控制器比常规PID控制器超调量小．它具有调节时间短，控制系统实时性和抗干扰能力强的特点．     

基于遗传算法的优化PID控制器设计

提出了一种基于遗传算法优化整定ＰＩＤ控制器的新方法，该方法首先将ＰＩＤ参数整定转化为求解一优化问题，进而应用遗传算法求出优化问题的解。给出了设计实例，并应用所提出的方法对导弹控制系统进行优化设计。     

基于差分进化算法的自行高炮随动系统PID参数整定

针对传统PID参数整定效率低且无法考虑构件间力元等因素对参数整定的影响问题,建立随动系统机电联合仿真模型,利用智能优化算法整定PID参数。建立了考虑行进间车体姿态扰动的随动控制系统模型,并结合上装虚拟样机建立随动系统的机电联合仿真模型,采用实车试验方法验证联合仿真模型的正确性。在此基础上,以时间乘以误差绝对值积分为优化目标函数,利用差分进化算法对PID参数进行整定,与原模型控制参数和遗传算法整定的参数进行比较。联合仿真结果表明：与原模型控制参数相比,使用差分进化算法整定的PID参数进行仿真,火力线控制误差的均方根值和标准差分别减少24.06%和25.20%,且收敛速度比遗传算法快;该建模方法和参数整定方法有效可行,对火力线控制精度优化具有理论参考价值。     

基于增强学习的无人直升机姿态控制器设计

自适应启发评价（AHC）增强学习结构分别逼近马尔可夫决策过程的值函数和策略函数．策略梯度增强学习能够将随机不确定的马尔可夫决策过程转换为确定性的马尔可夫决策过程。通过将AHC增强学习和策略梯度增强学习相结合，对PID控制器参数进行在线自适应整定，实现对无人直升机姿态控制性能的在线优化。仿真结果表明．与固定PID参数控制器相比，该算法能在线调整控制器参数．并很好地控制了无人直升机的悬停姿态。     

基于RBF神经网络的控制器参数优化设计研究

以单输入单输出控制系统为研究对象,为快速完成控制器参数整定及优化,提升系统动态性能和稳态性能,提出了一种基于RBF(Radial Basis Function)神经网络的控制器参数优化方法。利用RBF神经网络的局部逼近能力和自学习能力,构造出控制系统辨识与控制器参数优化双网络结构,实现了对被控对象的在线辨识及增量式不完全微分PID控制器参数的在线迭代,快速完成控制器参数的整定,在保证系统动态特性的同时,大幅提升稳定精度。     

基于MATLAB的自整定模糊PID控制系统

针对常规PID控制器参数整定不良、适应性差、控制精度不理想的现状，提出了动态过程中参数自动整定的模糊PID控制系统。并利用MATLAB的SUMLINK工具箱，对系统进行仿真，仿真试验结果表明模糊PID控制鲁棒性好、控制精度提高。     

永磁同步电机静止参数辨识及电流环控制器自动参数整定

在永磁同步电机数字控制系统中,电流环控制器的参数整定是影响电流环带宽和系统控制性能的重要因素。为优化控制参数设计流程,提出一种基于静止参数辨识的自动整定方法,使控制系统在匹配不同电机平台时具有通用性。在永磁同步电机静止条件下,通过两点式伏安法辨识定子电阻值,消除脉宽调制中死区对定子电阻辨识的影响;通过高频注入法激励定子绕组,运用离散傅里叶变换分别得到交直轴电感值。分析推导自动整定电流环控制器参数方法,并根据辨识参数设计电流环控制器,在两组永磁同步电机实验平台上进行实验。实验结果表明：该控制方法可以使永磁同步电机具有良好的动态和静态性能;永磁同步电机静止参数辨识及电流环控制器参数自动整定方法是有效的。     

基于遗传算法的一类碟形飞行器的控制研究

为了改善传统PID控制器的控制效果，简要介绍了自适应在线遗传算法整定PID参数的控制方法,并将其应用于一类碟形飞行器的纵向控制系统中，仿真结果表明，采用自适应在线遗传算法整定的PID控制器具有良好的控制品质。     

多指标约束下PID 参数统一优化定量整定方法

在分析现有PID控制器参数整定方法局限性的基础上,提出并建立一种多指标约束下PID参数统一优化定量整定方法。给出通过Matlab仿真分析筛选确定PID参数最优组合值的方法,介绍其实用方案:基于原始系统单位阶跃响应曲线估算PID初值的方法、制定多指标约束的方法、筛选PID优化值的具体方案和Matlab仿真软件流程图等,最后给出多个代表性的实例分析。结果表明:该方法能快速完成PID控制系统的优化设计,并且不需要PID参数经验值和计算/调试P控制的临界振荡增益和周期。     

基于PSO算法的二自由度PID控制器参数优化

根据粒子群优化算法具有在参数空间寻优的特点 ,提出了一种利用粒子群优化算法对二自由度PID控制器参数优化整定的方法.通过对工业被控对象的仿真表明了该方法优于常规参数整定方法,且所设计的控制器具有一定的优越性.     

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.     

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 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.     

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.