变时延移动Ad-Hoc网络容量非合作规划博弈模型的渐近稳定性

移动Ad-Hoc网络容量的稳定性是保证其服务质量的关键性质之一.本文提出一种新颖的考虑时变传播时延的非合作规划博弈移动Ad-Hoc网络容量分析模型稳定性控制技术.首先求得加入时变传播时延项的非合作规划博弈移动Ad-Hoc网络容量分析模型的源节点发送流量速率演化方程组—–一类非线性时变时滞微分方程组,在此基础上采用描述器技术结合线性矩阵不等式技术得到该模型的渐进稳定性准则,并设计了模型稳定性控制的迭代算法.由于是基于等价模型变换,所提出的渐近稳定性判别准则具有较小的保守性.仿真实验验证了本算法的有效性.本建模与分析方法虽以具体的非合作规划博弈移动Ad-Hoc网络容量分析模型为例,但其可以应用于一般的移动Ad-Hoc网络容量稳定性控制问题.     

基于模糊逻辑的无人机定位系统设计

针对无人机定位精度问题,硬件设计采用模块化设计思想,以STM32系列的微控制器为核心,以微机械传感器和GPS 模块为基础,组成无人机组合导航系统;软件提出了基于“模糊逻辑”的加速度区间自适应算法,修正惯导定位误差随时间快速积累、GPS发射信号受阻,造成的连续定位能力和精度较差的问题,保证了系统定位精度,为小型自主起降固定翼无人机、多旋翼无人机定位奠定基础。     

基于双处理器的小型无人机飞行控制平台设计

针对传统的基于单处理器的飞行控制平台处理速度慢、解算精度低的不足,开发了一种基于ARM微处理器和DSP芯片双CPU架构的小型无人机飞行控制平台;描述了该平台的体系结构及各部分实现,给出了关键技术解决方法;通过搭建地面实时仿真环境,对GPS地速与空速、刹车控制量及反馈量等进行仿真,结果表明,飞控平台的处理速度和解算精度大大提高,满足系统控制要求, 具有较好的实用性。     

基于激光测距的无人机地形匹配飞行方法研究

为了解决现有民用无人机在山区等复杂地形下难以实现地形匹配飞行的问题,分析了地形匹配飞行的技术难点,提出了一种基于激光测距的无人机地形匹配飞行方法;先运用基于最小二乘法的拟合模型提高激光测距模块的精度,再利用激光测距模块分别实时测得无人机与地面的相对高度和地形的起伏角度,结合DMC-PID串级控制算法,使得无人机可以自主实现地形匹配飞行;该方法无需昂贵的地形检测传感器和复杂的软件算法,具有设备重量轻,应用难度低等特点;通过实地飞行测试,验证了该方法的有效性和可行性。      

无人机鲁棒伺服LQR飞行控制律设计

为抑制无人机飞行模态切换时舵面跳变使机体产生的大过载,降低无人机对舵系统及结构可用过载的要求,将鲁棒伺服LQR方法与经典控制方法相结合设计了飞行控制律;以俯仰角控制模态为例,对鲁棒伺服LQR控制方法的特性进行了分析,俯仰角速率回路采用鲁棒伺服LQR最优控制方法设计了控制律,俯仰角回路采用经典控制方法设计了控制律,并通过非线性数字仿真对控制律的控制效果进行了验证;仿真结果表明:鲁棒伺服LQR控制比常规PID控制超调量减小50%,且大大减小了响应初期的升降舵偏角突变,降低了对机体可用过载的要求;该控制律形式简单,易于工程实现。     

无人机机箱温度异变信号检测系统设计

针对传统的无人机温度检测系统对于无人机机箱温度异变信号的检测实时性和准确较低的问题,设计并实现了基于DS18B20温度传感器关联模型的无人机机箱温度异变信号检测系统,根据温度在不同位置的测量值不同,建立不同位置的关联模型,利用温度传感器之间的关联系数λ,判断不同位置的温度信号是否正常,并对温度异变信号发出警报;硬件设计主要包括温度传感器检测电路、数据处理模块、声光报警模块等;软件设计主要包括工作流程、DS18B20实时温度传感器关联性的程序实现等;最后对无人机100次的飞行提取机箱检测温度进行试验实验,通过温度传感器DS18B20对无人机机箱实际的温度数据进行检测,结果表明:机箱内部模块周围温度变化与散热风扇周围的温度平均温度变化相差在0.5℃以内,在误差允许范围内,相关性很大;另外,与传统系统对比可知,该系统的检测准确率高达95%以上,且稳定性强,能为无人机的安全飞行提供了可靠保障。     

小型固定翼无人机纵向姿态控制律的研究

针对无人机在实际飞行过程中受到外部环境影响大,控制精度不够高的问题;研究了一种模糊参数自整定PID控制方法来完成对无人机的纵向姿态的控制;该方法在传统的PID控制的基础上,利用无人机实际飞行中的数据,建立起模糊控制规则来实现PID参数自整定,最后在通过建立的纵向姿态模型上进行仿真控制,得出仿真曲线;仿真实验结果表明,所设计的模糊PID控制器,相比于传统的PID控制器具有更好的控制性能,并且具有很好的抗干扰能力,能够满足无人机控制系统的要求。     

民用小型无人机飞行控制系统硬件设计

针对民用无人机体积小、重量轻、结构简单、可靠性高等要求,给出了一种以STM32F103RE微控制器为核心的小型无人机的硬件系统设计方案,并详细介绍了系统整体方案设计以及主要的功能模块;通过详细的结构框图描述了如何有效的将各功能模块组成一个稳定的系统;在小型固定翼无人机上的飞行测试验证了该设计方案的可行性和可靠性;该系统实现体积小,可以封装到一个小盒子里面,所有接口单独引出,可以挂载到不同的载体上;该系统具有精炼、低成本、可靠性高的特点,适合批量生产使用。     

无人机飞行仿真平台控制系统设计

为了便于在实验室模拟无人机在空中的偏航、俯仰、翻滚3个自由度的飞行姿态,设计了一套用于验证飞行控制系统的三轴转台半物理仿真系统;给出了系统的硬件结构和控制策略;转台系统采用TMS320LF2407作为核心处理器并采用旋转变压器作为反馈环节组成位置和速度的闭环控制;为了提高传统PID的控制精度,提出了一种速度、加速度前馈补偿PID控制方法,有效解决了位置随动系统的快速性和准确性这一矛盾;实验运行结果表明,该平台运行良好,控制精度高,能较好实现对无人机飞行姿态的模拟。     

基于VxWorks的小型无人机飞行控制软件设计

针对小型无人机功能日益复杂,迫切需要提高实时性与可靠性等现状,开发了一套基于VxWorks实时操作系统的小型无人机飞行控制软件,实现了无人机自主起飞、空中巡航和自主着陆等飞行控制功能;在完成软件需求分析的基础上,设计了飞行控制软件的总体结构,并结合VxWorks操作系统的运行机制给出飞行控制软件模块化设计方案,着重介绍了多任务环境下任务划分及优先级分配策略;半物理飞行仿真试验表明:该飞行控制软件能够实现自主、指令、人工3种飞行模式下的飞行控制功能,具有良好的实时性和可靠性,满足飞行控制软件最初的设计需求,同时大大降低了开发难度,提高了软件的可维护性和可移植性。     

Second-Order Consensus of Multiple Agents with Coupling Delay

In this paper, we investigate two kinds of second-order consensus algorithms for multiple agents with coupling delay under general fixed directed information topology. Stability analysis is performed based on Lyapunov- Krasovskii functional method. Delay-dependent asymptotical stability condition in terms of linear matrix inequalities （LMIs） is derived for the second-order consensus algorithm of delayed dynamical networks. Both delay-independent and delay-dependent asymptotical stability conditions in terms of LMIs are derived for the second-order consensus algorithm with information feedback.     

New synchronization analysis for complex networks with variable delays

This paper deals with the issue of synchronization of delayed complex networks. Differing from previous results,the delay interval [0,d(t)] is divided into some variable subintervals by employing a new method of weighting delays. Thus,new synchronization criteria for complex networks with time-varying delays are derived by applying this weighting-delay method and introducing some free weighting matrices. The obtained results have proved to be less conservative than previous results. The sufficient conditions of asymptotical synchronization are derived in the form of linear matrix inequality,which are easy to verify. Finally,several simulation examples are provided to show the effectiveness of the proposed results.     

Stability analysis of Markovian jumping stochastic Cohen Grossberg neural networks with discrete and distributed time varying delays

In this paper, the global asymptotic stability problem of Markovian jumping stochastic Cohen-Grossberg neural networks with discrete and distributed time-varying delays （MJSCGNNs） is considered. A novel LMI-based stability criterion is obtained by constructing a new Lyapunov functional to guarantee the asymptotic stability of MJSCGNNs. Our results can be easily verified and they are also less restrictive than previously known criteria and can be applied to Cohen-Grossberg neural networks, recurrent neural networks, and cellular neural networks. Finally, the proposed stability conditions are demonstrated with numerical examples.     

Novel delay-dependent stability criteria for neural networks with interval time-varying delay

The problem of delay-dependent asymptotic stability for neural networks with interval time-varying delay is investigated. Based on the idea of delay decomposition method, a new type of Lyapunov-Krasovskii functional is constructed. Several novel delay-dependent stability criteria are presented in terms of linear matrix inequality by using the Jensen integral inequality and a new convex combination technique. Numerical examples are given to demonstrate that the proposed method is effective and less conservative.     

Observer-based passive control for uncertain linear systems with delay in state and control input

This paper deals with the robust passivity synthesis problem for a class of uncertain linear systems with time-varying delay in state and control input. The parameter uncertainties are norm-bounded and allowed to appear in all matrices of the model. The problem aims at designing an observer-based dynamic output-feedback controller that robustly stabilizes the uncertain systems and achieves the strict passivity of closed-loop systems for all admissible uncertainties. By converting the problem at hand into a class of strictly passive control problem for a parameterized system, the explicit solution is established and expressed in terms of a linear matrix inequality. A numerical example is provided to demonstrate the validity of the proposed approach.     

An Adaptive Deblurring Vehicle Detection Method for High-Speed Moving Drones: Resistance to Shake

Vehicle detection is an essential part of an intelligent traffic system, which is an important research field in drone application. Because unmanned aerial vehicles (UAVs) are rarely configured with stable camera platforms, aerial images are easily blurred. There is a challenge for detectors to accurately locate vehicles in blurred images in the target detection process. To improve the detection performance of blurred images, an end-to-end adaptive vehicle detection algorithm (DCNet) for drones is proposed in this article. First, the clarity evaluation module is used to determine adaptively whether the input image is a blurred image using improved information entropy. An improved GAN called Drone-GAN is proposed to enhance the vehicle features of blurred images. Extensive experiments were performed, the results of which show that the proposed method can detect both blurred and clear images well in poor environments (complex illumination and occlusion). The detector proposed achieves larger gains compared with SOTA detectors. The proposed method can enhance the vehicle feature details in blurred images effectively and improve the detection accuracy of blurred aerial images, which shows good performance with regard to resistance to shake.     

Improved delay-dependent robust H_∞ control of an uncertain stochastic system with interval time-varying and distributed delays

In this paper, the robust H∞control problem for a class of stochastic systems with interval time-varying and distributed delays is discussed. The system under study involves parameter uncertainty, stochastic disturbance, interval time-varying,and distributed delay. The aim is to design a delay-dependent robust H∞control which ensures the robust asymptotic stability of the given system and to express it in the form of linear matrix inequalities（LMIs）. Numerical examples are given to demonstrate the effectiveness of the proposed method. The results are also compared with the existing results to show its conservativeness.     

Cluster exponential synchronization of a class of complex networks with hybrid coupling and time-varying delay

This paper deals with the cluster exponential synchronization of a class ot complex networks wlm nyorm coupm~g and time-varying delay. Through constructing an appropriate Lyapunov-Krasovskii functional and applying the theory of the Kronecker product of matrices and the linear matrix inequality （LMI） technique, several novel sufficient conditions for cluster exponential synchronization are obtained. These cluster exponential synchronization conditions adopt the bounds of both time delay and its derivative, which are less conservative. Finally, the numerical simulations are performed to show the effectiveness of the theoretical results.     

基于状态观测器的分数阶时滞混沌系统同步研究

研究分数阶时滞混沌系统同步问题,基于状态观测器方法和分数阶系统稳定性理论,设计分数阶时滞混沌系统同步控制器,使得分数阶时滞混沌系统达到同步,同时给出了数学证明过程.该同步控制器采用驱动系统和响应系统的输出变量进行设计,无需驱动系统和响应系统的状态变量,简化了控制器的设计,提高了控制器的实用性.利用Lyapunov稳定性理论和分数阶线性矩阵不等式,研究并给出了同步控制器参数的选择条件.以分数阶时滞Chen混沌系统为例,设计基于状态观测器的同步控制器,实现了分数阶时滞Chen混沌系统同步,并将其应用于保密通信系统中.仿真结果证明了该同步方法的有效性.