Design of PID controller with incomplete derivation based on differential evolution algorithm

To determine the optimal or near optimal parameters of PID controller with incomplete derivation, a novel design method based on differential evolution （DE） algorithm is presented. The controller is called DE-PID controller. To overcome the disadvantages of the integral performance criteria in the frequency domain such as IAE, ISE, and ITSE, a new performance criterion in the time domain is proposed. The optimization procedures employing the DE algorithm to search the optimal or near optimal PID controller parameters of a control system are demonstrated in detail. Three typical control systems are chosen to test and evaluate the adaptation and robustness of the proposed DE-PID controller. The simulation results show that the proposed approach has superior features of easy implementation, stable convergence characteristic, and good computational efficiency. Compared with the ZN, GA, and ASA, the proposed design method is indeed more efficient and robust in improving the step response of a control system.     

A Novel Concatenated Chaotic Communication System

A strategy for a novel concatenated chaotic communication system is presented. The transmitter system comprises chaotic turbo encoder and logistic CSK block in a serially concatenated form. Chaotic turbo code is capable of reducing bit error rate (BER) of the chaotic system in the AWGN channel. Through the chaotic turbo encoder, the coded sequence, which has quasi-chaotic properties, will be transmitted into the logistic CSK block. Having a very sensitive dependence on initial conditions of the map, the logistic CSK block can also be taken as the chaotic authentication method. The receiver, which has logistic demodulation block and chaotic decoder, is a linear asymptotic approximation to the inverse of the transmitter system. A chaotic iterative soft-decision decoding algorithm is also developed based on conventional maximum A posteriori decoding algorithm. At last, a two-step authentication method of this chaotic system is also presented.     

Self-adaptive learning based discrete differential evolution algorithm for solving CJWTA problem

Cooperative jamming weapon-target assignment （CJWTA） problem is a key issue in electronic countermeasures （ECM）. Some symbols which relevant to the CJWTA are defined firstly. Then, a formulation of jamming fitness is presented. Final y, a model of the CJWTA problem is constructed. In order to solve the CJWTA problem efficiently, a self-adaptive learning based discrete differential evolution （SLDDE） algorithm is proposed by introduc-ing a self-adaptive learning mechanism into the traditional discrete differential evolution algorithm. The SLDDE algorithm steers four candidate solution generation strategies simultaneously in the framework of the self-adaptive learning mechanism. Computa-tional simulations are conducted on ten test instances of CJWTA problem. The experimental results demonstrate that the proposed SLDDE algorithm not only can generate better results than only one strategy based discrete differential algorithms, but also outper-forms two algorithms which are proposed recently for the weapon-target assignment problems.     

MIMO-DCSK communication scheme and its performance analysis over multipath fading channels

The differential chaotic shift keying （DCSK） communication in multiple input multiple output （MIMO） multipath fading chan- nels is considered. A simple MIMO-DCSK communication scheme based on orthogonal multi-codes （OMCs） and equal gain combination （EGC） is proposed, in which OMCs are used to spread the same information bit at each transmitting antenna and the infor- mation bit is detected by EGC at receiving antenna. The OMCs are constructed from one chaotic sequence by means of othogo- nal space-time block coding （OSTBC）. The output signal-to-noise ratio （SNR） after EGC is given based on central limit theory （CLT）, and it can effectively exploit the spatial diversity of the underlying MIMO system. Simulation results show that the full spatial diversity gain is achieved without channel estimation in the MIMO-DCSK communication scheme and it performs better than MC-EGC for a large number of transmitting antennas.     

Chaos in a Damped Power System

The analytical investigation of a damped power system has been made based on Holmes and Marsden's theorems. The condition for the occurrence of chaotic motions in the system is that the damping factor has to possess negative values. The numerical simulation results concur very well with theoretical predictions.     

Homologous fault monitoring technology of redundant INS in airborne avionics systems

Redundant technology plays an important role in improving the reliability and fault-tolerance of the airborne avionics systems. A Markov state transition model is introduced to the reliability analysis of the redundant inertial navigation system （RINS） in airborne navigation systems. An information processing mechanism based on difference filtering is put forward to strengthen the consistency between the outputs of the equal-precision inertial navigation system （INS）. On this basis, the homologous fault monitoring algorithm is designed to realize the homologous fault monitoring of RINS. The simulation is carried out based on the above algorithms, and the results verify the effectiveness of the proposed fault monitoring algorithm based on difference filtering. Research results have good reference value for the configuration and design of RINS in airborne integrated avionics systems.     

Autotuning algorithm of particle swarm PID parameter based on D-Tent chaotic model

An improved particle swarm algorithm based on the D-Tent chaotic model is put forward aiming at the standard particle swarm algorithm. The convergence rate of the late of proposed algorithm is improved by revising the inertia weight of global optimal particles and the introduction of D-Tent chaotic sequence. Through the test of typical function and the autotuning test of proportionalintegral-derivative （PID） parameter, finally a simulation is made to the servo control system of a permanent magnet synchronous motor （PMSM） under double-loop control of rotating speed and current by utilizing the chaotic particle swarm algorithm. Studies show that the proposed algorithm can reduce the iterative times and improve the convergence rate under the condition that the global optimal solution can be got.     

Performances of improved Tent chaos-based FM radar signal

A novel algorithm is proposed to solve the poor performance problem of the Tent chaos-based frequency modulation(FM) signal for range-Doppler imaging,which takes it into complex multi-segment system by increasing its segments.The simulation results show that the effectiveness of the proposed algorithm,as well as the performance of the improved Tent FM signal is obvious in a multipath or noise propagation environment.     

Intelligent fault-tolerant algorithm with two-stage and feedback for integrated navigation federated filtering

In order to take full advantage of federated filter in fault-tolerant design of integrated navigation system, the limitation of fault detection algorithm for gradual changing fault detection and the poor fault tolerance of global optimal fusion algorithm are the key problems to deal with. Based on theoretical analysis of the influencing factors of federated filtering fault tolerance, global fault-tolerant fusion algorithm and information sharing algorithm are proposed based on fuzzy assessment. It achieves intelligent fault-tolerant structure with two-stage and feedback, including real-time fault detection in sub-filters, and fault-tolerant fusion and information sharing in main filter. The simulation results demonstrate that the algorithm can effectively improve fault-tolerant ability and ensure relatively high positioning precision of integrated navigation system when a subsystem having gradual changing fault.     

Improved gravitational search algorithm based on free search differential evolution

This paper presents an improved gravitational search algorithm (IGSA) as a hybridization of a relatively recent evolutionary algorithm called gravitational search algorithm (GSA), with the free search differential evolution (FSDE). This combination incorporates FSDE into the optimization process of GSA with an attempt to avoid the premature convergence in GSA. This strategy makes full use of the exploration ability of GSA and the exploitation ability of FSDE. IGSA is tested on a suite of benchmark functions. The experimental results demonstrate the good performance of IGSA.     

卫星/伪卫星/惯性组合着舰导引算法

针对舰载机安全着舰对高精度、高可靠性着舰导引系统的迫切需求,研究了卫星/伪卫星/惯性组合着舰导引技术,基于几何精度因子(geometric dilution of precision, GDOP)计算提出了伪卫星在舰船上的布设方案,并设计了其导航电文结构。研究了卫星/伪卫星/惯性组合着舰导引算法,利用卫星及伪卫星的双差分载波相位信息,采用改进的模糊度最小二乘去相关平差(least squares ambiguity decorrelation adjustment,LAMBDA)迭代算法解算其双差分整周模糊度,并基于舰载机运动模型建立滤波方程解算出舰机相对运动信息,再与惯导数据进行信息融合得到高精度的导引信息。仿真结果表明,提出的卫星/伪卫星/惯性着舰导引技术横向定位误差在0.3m以内,纵向定位误差在0.1m以内,高度定位误差在0.3m以内,可以满足舰载机着舰的要求,与卫星/惯性组合导引相比,该组合方式大大提高了垂直方向的定位精度,这对于确保安全着舰极为重要。并且,提出的着舰导引技术不仅精度高,而且工作连续可靠、抗干扰能力强,对保障舰载机着舰安全有重要的意义。     

基于大地坐标系的IMM航空器短期航迹外推

针对航路飞行阶段的航空器, 通过对比空间直角坐标系和大地坐标系的优劣, 采用大地坐标系表示航空器的位置; 基于大地坐标系, 将航空器的运动解耦成3个方向上的独立运动, 分别建立每个方向上的子模型; 使用交互式多模型(interacting multiple model, IMM)算法对航空器的航迹进行跟踪。仿真结果表明, 基于大地坐标系的IMM算法对于航空器有很好的轨迹追踪性能; 根据航空器末时状态及各个子模型的概率分布进行航空器的航迹短期外推, 基于大地坐标系的IMM算法的航迹外推性能优于基于空间直角坐标系的IMM算法的航迹外推性能。     

基于WMF与LSE的序列图像匹配制导滤波融合算法

为了改善匹配制导系统可靠性及匹配精度,提出了一种新的基于WMF与LSE的序列图像匹配结果滤波融合算法。分析了序列图像匹配制导滤波融合的基本问题,设计了一种加窗中值滤波器,并将其应用于纵向匹配位置序列的滤波处理,采用LSE对匹配位置序列进行最优参数估计,给出了滤波融合算法的基本原理及实现框图。仿真实验及实例分析验证了本文算法在消除误匹配点及减小随机匹配误差干扰方面的有效性、实用性。     

结冰条件下飞机全包线模态特性分析方法

针对飞机带冰飞行时全包线范围内飞行品质评估问题, 提出一种结合自适应拟配初值计算与时域等效系统拟配对整个包线内的典型模态参数快速计算方法。建立了典型的人-机-环系统模型, 通过数值仿真得到飞机对于方向舵倍脉冲操纵的响应数据, 在分析时域响应数据特征的基础上, 提出自适应计算横航向等效系统拟配初值的方法, 解决了拟配初值的敏感性问题。运用时域等效系统拟配法, 分别获取了某型飞机干净构型及不同结冰严重程度时, 整个包线范围内横航向模态参数特性, 进而从整体的角度量化了结冰对飞机飞行品质的影响。仿真结果表明，所提方法在全包线范围内具有较好的适应性，为快速分析飞行器纵横向典型模态特性提供了新的思路，具有较好的工程应用前景。     

基于非线性动态逆滑模的纵向着舰系统设计

通常发生的舰载机进舰着舰事故中,大多数是由于舰载机纵向航迹控制不好导致的。因此,针对着舰过程中的舰载机非线性运动模型,考虑舰尾流扰动的影响,提出了一种基于非线性动态逆的滑模控制方法,应用在纵向着舰系统的3个控制回路的设计中,来解决精确控制飞行轨迹的问题,并进行了航迹纠偏测试。最后,仿真结果表明,所设计的纵向着舰系统具有较强的鲁棒性和快速跟踪性,提高了舰载机着舰航迹精度,减少了下滑轨迹误差,满足了美国海军安全着舰指标要求。     

一种广义猫映射混沌系统及其性能分析

为了改进基于猫映射混沌系统的加密算法的安全性，在传统的二维猫映射混沌系统的基础上，蛤出了一种基于广义加法运算的广义猫映射混沌系统，生成的混沌序列具有良好的伪随机特性，同时对生成的广义混沌序列的自相关性和平衡性进行了分析．实验结果表明，应用本文给出的方法生成的广义混沌序列具有较好的随机性、自相关性和平衡性。     

基于三维混沌猫映射图像加密算法的改进

针对基于三维混沌猫映射的图像钥加密算法,提出了一种有效的改进算法。该算法使用随机扫描进行加密预处理,并在扩散过程和密钥产生器中分别使用双密钥和组密钥的方式,而且采用混沌物理量进一步衡量该加密系统的性能。仿真结果表明,该方法具有高置乱程度、良好的扩散性能和足够大的密钥空间,可获得足够高的安全性,不仅能抵抗差分攻击、选择明文攻击、统计攻击等,而且取得了复杂度和速度的良好折中,适合应用于实时的按安全级别加密的网络图像加密中。     

舰载机多机一体化机务保障调度方法

为了有效提升舰载机多机机务保障的效率和保障人员的利用率,根据单机机务保障流程约束特性,建立了基于多计划评审技术网络的多目标多机一体化机务保障调度模型。针对问题的求解,提出了一种自适应混合差分进化算法。首先根据调度的网络化排队过程,设计了基于事件调度策略的解码方法。其次为了协调算法“探索”与“开发”的能力,引入了自适应的变异操作和交叉、变异参数控制。再次,针对工序块的平行组合排列特征,提出了4种邻域结构,进而在算法框架中嵌入了一种自适应多邻域局部搜索策略。最后通过仿真实验验证了模型和算法的可行性和有效性。     

基于APDE-RBF神经网络的网络安全态势预测方法

为了提高径向基函数(radical basis function, RBF)神经网络对网络安全态势的预测精度,提出了一种基于吸引力传播(affinity propagation, AP)聚类和差分进化(differential evolution, DE)优化RBF神经网络的算法。首先,利用AP聚类算法对样本数据进行划分聚类,从而获得RBF的中心和网络的隐含层节点数;其次,利用AP聚类得出种群差异度,自适应地改变DE算法的缩放因子和交叉概率,对RBF的宽度和连接权值进行优化;同时为了避免陷入局部最优以及跳出局部极值点,对每一代种群的精英个体和种群差异度中心进行混沌搜索。通过仿真实验表明,此算法在泛化能力增强的同时,对网络安全态势也达到了较高的预测精度。     

求解连续空间优化问题的量子差分混合优化算法

借鉴量子计算的相关原理和差分进化思想,提出一种用于连续空间优化问题的量子差分混合优化算法。算法的核心是构造由决策向量的分量和量子位概率幅为等位基因的实数编码染色体;采用依据染色体的具体形式设计的互补变异进化部分优秀个体,以加快算法的收敛速度;利用差分进化思想进化部分随机选取个体,以保持算法的全局搜索能力和鲁棒性。对Benchmark函数测试表明,该算法具有寻优能力强、搜索精度高和稳定性好的特点。应用该算法求解路基沉降预测模型参数估计问题,能够有效提高实测沉降数据的拟合精度.