改进PSO算法及在无人机路径规划中的应用

在无人机路径规划问题中,传统算法存在计算复杂与收敛慢等缺点,粒子群优化算法(PSO)得益于其算法原理简单、通用性强、搜索全面等特性,现多用于无人机航路规划.然而,常规PSO算法容易陷入局部最优,本文在优化调整自适应参数的基础上综合引入全局极值变异与加速度项,以平衡全局和局部搜索效率,避免种群陷入“早熟”.对基准测试函数进行测试的结果表明,本文所提改进PSO算法收敛速度更快,精度更高.在实例验证部分,首先提取飞行场景特征,结合无人机性能约束,进行环境建模;然后将多项运行约束和期望的最小化飞行时间均转化为罚函数,以最小化罚函数作为目标,构建无人机飞行任务场景下的航路规划模型,并利用本文所提改进粒子群算法进行求解,最后通过对比仿真验证了改进粒子群算法的高效性和实用性.     

基于改进鱼群算法的多无人机任务分配研究

多无人机协同任务分配问题是多无人机协同控制的关键,为解决单目标函数构建的任务分配模型不能满足决策者对战场环境大量信息的需求,以最大航程和最长任务执行时间作为多无人机任务分配的两个目标函数,依据多目标优化理论,建立了协同任务分配多目标优化模型.并采用了一种借鉴遗传算法中的变异思想的改进鱼群算法进行求解,得到多无人机任务分配的多目标最优解集,然后根据决策者的偏好选择最佳任务分配方案.最后将上述算法应用于多无人机协同任务分配中并进行了仿真,仿真结果验证了改进鱼群算法的收敛性及有效性,为多无人机协同任务分配优化提供了参考依据.     

基于改进粒子群算法的无人机爬升轨迹优化

研究无人机控制优化爬升性能问题,由于单独提高速度或节省燃油问题,均存在互相影响。为了使无人机能够快速、省油地爬升到预定高度,综合考虑了油耗和时间这两个因素。在分析了无人机爬升段数学模型的基础上,提出将油耗和时间的综合运营成本作为优化指标,并提出了一种改进粒子群算法的无人机爬升轨迹优化方法。将无人机轨迹优化问题转化为有约束的参数优化问题,并用改进粒子群算法进行参数优化,从而得到综合指标最优的爬升轨迹。对某无人机实例进行爬升轨迹优化,仿真结果比传统方法更节省了运营成本,证明了改进方法的优越性。     

一种新的融合粒子群算法的混合蟑螂群算法

针对连续蟑螂算法存在初始解质量不高和算法评价次数过多的问题,提出了一种融合了粒子群算法的混合蟑螂群算法并应用于函数优化问题.首先由基本粒子群算法快速收敛到解空间内一个相对优的解,然后由一种改进的蟑螂算法完成全局寻优.仿真结果显示:混合蟑螂算法具有收敛速度快、求解精度高的特点,其算法整体性能优于已存在的连续蟑螂算法.     

无人机虚拟现实仿真的设计与实现

讨论了在PC机上实现无人机虚拟现实仿真的系统结构、实现平台、模型和仿真数据库的组织实现方法。讨论了图形仿真各个子模块的实现方法,交解决了无人机模型的位姿自动校准问题。     

A multi-objective mixed-model assembly line sequencing problem in order to minimize total costs in a Make-To-Order environment,considering order priority

Nowadays, mixed-model assembly line is used increasingly as a result of customers’ demand diversification. An important problem in this field is determining the sequence of products for entering the line. Before determining the best sequence of products, a new procedure is introduced to choose important orders for entering the shop floor. Thus the orders are sorted using an analytical hierarchy process (AHP) approach based on three criteria: critical ratio of each order (CR_o), Significance degree of customer and innovation in a product, while the last one is presented for the first time. In this research, six objective functions are presented: minimizing total utility work cost, total setup cost and total production rate variation cost are the objectives which were presented previously, another objective is minimizing total idle cost, meanwhile two other new objectives regarding minimizing total operator error cost and total tardiness cost are presented for the first time. The total tardiness cost tries to choose a sequence of products that minimizes the tardiness cost for customers with high priority. First, to check the feasibility of the model, GAMS software is used. In this case, GAMS software could not search all of the solution space, so it is tried in two stages and because this problem is NP-hard, particle swarm optimization (PSO) and simulated annealing (SA) algorithms are used. For small sized problems, to compare exact method with proposed algorithms, the problem must be solved using meta-heuristic algorithms in two stages as GAMS software, whereas for large sized problems, the problem can be solved in two ways (one stage and two stages) by using proposed algorithms; the computational results and pairwise comparisons (based on sign test) show GAMS is a proper software to solve small sized problems, whereas for a large sized problem the objective function is better when solved in one stage than two stages; therefore it is proposed to solve the problem in one stage for large sized problems. Also PSO algorithm is better than SA algorithm based on objective function and pairwise comparisons.     

一种非线性PID控制算法的仿真研究

研究PID控制系统优化问题,工业控制被控对象均具有非线性、时变和大时滞性,引起系统的品质性能差,传统的线性控制难以达到所要求精度。为了提高系统控制精度,利用PID控制器各增益参数与偏差信号间的非线性关系,提出一种非线性PID控制算法。首先将PID参数转化为优化问题,然后采用粒子群算法的全局、并行搜索能力对非线性控制参数进行求解,得到一组最优的PID控制参数。仿真结果表明,相对于传统线性PID控制,非线性PID控制器超调小,调节时间短,并提高了控制精度,有效解决了传统PID难以准确控制非线性对象的难题。     

Optimal concurrent design based upon distributed product development life-cycle modeling

This research introduces an optimal concurrent design approach based upon a previously developed distributed product development life-cycle modeling method. In this approach, the product realization process alternatives and relevant activities are modeled at different locations that are connected through the Internet. Relations among these alternative activities are described by an AND/OR graph. The optimal product realization process alternative and its parameter values are identified using a multi-level optimization method. Genetic programming (GP) and particle swarm optimization (PSO) are employed for identifying the optimal product realization process alternative and the optimal parameter values of the feasible alternatives, respectively.     

基于密度的微粒群优化混合聚类算法

在分析了现有的基于密度的聚类算法的基础上,结合微粒群算法,提出了一种基于密度的微粒群混合聚类算法。相对于DENCLUE聚类算法,该算法能够对使用的资源进行有效的控制,有利于实现对数据库数据的增量处理。实验证明了算法的有效性。     

基于粒子群优化算法的PID控制器参数整定

PID控制器的性能完全依赖于其参数的整定和优化,但参数的整定及在线自适应调整对常规的PID控制器是难以解决的问题。根据粒子群算法具有对整个参数空间进行高效并行搜索的特点,提出了一种基于粒子群优化算法整定PID控制器参数的设计方法,并定义了一种新的性能指标函数来评价PID控制器的性能。现以二阶的船舶控制装置为研究对象,运用粒子群优化方法对PID控制器参数进行了寻优研究。仿真结果表明,该方法比一般PID参数整定方法具有更好的控制性能指标,有着一定的工程应用价值。     

基于优化粒子群算法的无人机航路规划

针对粒子群优化(PSO)算法的无人机(UAV)航路规划问题,引入惯性权重和自然选择对粒子群算法进行优化,以提高基本粒子群算法收敛速度,防止陷入局部最优.算法分析惯性权重对粒子群算法的影响,进而调整惯性因子,提高算法的搜索能力;利用自然选择的便利性和规律性等特点,更新粒子群算法的粒子;同时通过对无人机的可行航向进行限定,缩小搜索范围.仿真实验表明:基于粒子群优化算法的无人机航路规划不仅缩短了最优航路,而且提高了搜索速度.     

基于PSO的E型双频天线自适应优化设计

研究天线性能优化问题,为了满足多个无线通信系统实现多系统收发共用,天线需在宽频带及不同频段下工作.为了得到优化的谐振频率和宽带,通过在矩形微带线上开两条对称的槽得到E型贴片天线,实现天线的双频功能,利用电磁仿真软件IE3D建立天线模型,通过IE3D对天线的性能进行仿真和分析,同时使用粒子群优化算法对其关键性参数进行了自适应优化,得出天线的具体尺寸.仿真结果表明,天线-10dB阻抗带宽分别为125 MHz(2400-2525MHz)和275MHz(5575-5850MHz),能够满足WLAN(2400-2484 MHz/5725-5825 MHz)的通信需求.优化的天线结构简单,具有很好的双频特性,在工作带宽内有很好的全向辐射特性.     

摄像机标定方法的建模与仿真研究

研究摄像机定位优化控制问题,摄像机镜头存在多种非线性畸变,对标定路径和图像质量产生一定的影响,难以采用精确数学模型来描述,针对传统方法的摄像机标定准确率低。为了提高摄像机的标定准确率,利用LSSVM较好的处理非线性预测能力,建立一种PSO-LSSVM的摄像机标定模型。将摄像头采集到的图像坐标作为输入,将世界坐标作为输出,通过采用LSSVM精确逼近输入与输出的复杂非线性关系,采用PSO寻找LSSVM最优参数,提高标定准确率。通过标定模型进行对比实验,实验结果表明,PSO-LSSVM不仅加快标定速度,且提高了摄像机标定的准确率。     

A modified particle swarm optimization with multiple subpopulations for multimodal function optimization problems

In this paper, a modified particle swarm optimization (PSO) algorithm is developed for solving multimodal function optimization problems. The difference between the proposed method and the general PSO is to split up the original single population into several subpopulations according to the order of particles. The best particle within each subpopulation is recorded and then applied into the velocity updating formula to replace the original global best particle in the whole population. To update all particles in each subpopulation, the modified velocity formula is utilized. Based on the idea of multiple subpopulations, for the multimodal function optimization the several optima including the global and local solutions may probably be found by these best particles separately. To show the efficiency of the proposed method, two kinds of function optimizations are provided, including a single modal function optimization and a complex multimodal function optimization. Simulation results will demonstrate the convergence behavior of particles by the number of iterations, and the global and local system solutions are solved by these best particles of subpopulations.     

无人机空中加油控制设计与仿真

无人机空中加油控制精度问题,无人受油机模型的各种不确定性与来自外部的各种干扰归结为扰动,造成控制精度差。为解决上述问题,提出一种免疫粒子群优化算法的自抗扰无人机自主空中加油飞行控制律设计方法。利用自抗扰控制能够自动检测并补偿内部与外部干扰影响的特点,并利用扩张状态观测器进行估计与补偿,从而增强了所设计飞行控制律的鲁棒性,用免疫粒子群优化算法对自抗扰控制器参数进行了优化研究,以提高设计效率。仿真结果表明,所设计的自抗扰自主空中加油控制系统具有优良的控制性能与较高的控制精度,能够满足无人机自主空中加油的要求。     

基于水平集的PSO算法的改进

粒子群优化算法PSO(Particle Swarm Optimization)目前仍存在着早熟收敛和收敛速度较慢的难题,提出一种新的PSO改进算法.该算法利用水平集对PSO的每一代粒子按照适应度进行划分,把与目标相关的所有信息结合在一起,改变了原有的PSO进化公式,提高了算法的收敛速度;其次,对于每一代的某个个体进行变异,使其变异到粒子密度低的空间中去,从而提高了粒子的多样性,减少早熟发生的机会.实验证明,这种算法是有效的.     

A novel Hough transform based on eliminating particle swarm optimization and its applications

Hough transform (HT) is a well established method for curve detection and recognition due to its robustness and parallel processing capability. However, HT is quite time-consuming. In this paper, an eliminating particle swarm optimization (EPSO) algorithm is employed to improve the speed of a HT. The parameters of the solution after Hough transformation are considered as the particle positions, and the EPSO algorithm searches the optimum solution by eliminating the “weakest” particles to speed up the computation. An accumulation array in Hough transformation is utilized as a fitness function of the EPSO algorithm. The experiments on numerous images show that the proposed approach can detect curves or contours of both noise-free and noisy images with much better performance. Especially, for noisy images, it can archive much better results than that obtained by using the existing HT algorithms.     

粒子群算法的交互性与随机性分析

在现有分析结论的基础上, 分别采用优化的凸性理论和概率收敛理论, 分析了粒子群 (Particle swarm optimization, PSO) 算法的交互性和随机性对算法的影响. 分析得出, 在不考虑随机性的条件下, 当 PSO 算法优化单峰函数时, 交互性使粒子最终收敛于全局最优粒子位置; 当 PSO 算法优化多峰函数时, 交互性未必使粒子最终收敛于全局最优位置. 但如果考虑随机性, 算法优化的目标函数无论是单峰函数还是多峰函数, 粒子都会依概率收敛于最优位置. 通过基准函数的实验验证了分析的结论.