车灯线光源的优化设计模型

本文主要研究了车灯线光源长度在满足光照强度的设计要求和功率节能的最优解策略。分别用正向光线追迹、逆向光线追迹、方程组模型求解,得到的结果基本一致,但计算复杂度逐级下降、求解精度逐级上升,最后得出线性光源长度为4.060(mm)。最后,对设计规范从照射车距(安全性)、视认度(驾驶员)、车灯功率(节能原则)来评价其合理性。     

变焦佳点集遗传算法

通过使用数论佳点集理论与方法构造出佳点交又算子,佳点集遗传算法(GGA)具有更快的收敛速度和精度,且避免了常见的早期收敛现象,但是二进制编码的佳点集遗传算法在位串长度确定的情况下无法克服二进制与实数之间的映射误差。针对二进制编码遗传算法存在从最高位到最低位依次收敛的多米诺现象,提出含有变焦因子的佳点集遗传算法来变相增加位串编码长度以期缩小该映射误差,提高搜索效率和求解精度。通过不同维数下的Benchmark测试函数的仿真结果表明,改进的算法具有全局收敛、求解精度和搜索效率高的优点。     

基于遗传算法的最大功率点跟踪

最大功率点对于提高光伏发电系统的整体效率具有重要作用,对优化算法在最大功率点跟踪中的应用进行了研究。基于光伏发电原理,通过Matlab和S函数建立了太阳能电池的仿真计算模型。针对传统最大功率点跟踪方法自动跟踪速度与跟踪精度难于兼顾的问题,应用遗传算法建立了最大功率点跟踪模型。仿真结果表明,当光照强度、电池温度变化时,模型能够快速、精确地跟踪最大功率点。通过与爬山法的对比研究,表明在相同跟踪时间限定下,遗传算法具有更高的跟踪精度,具有良好的综合性能。     

蜂群遗传算法在一维下料问题中的应用

针对一维下料优化问题,根据企业的实际生产情况,考虑能够满足和不满足生产两种情况,建立一个新的优化模型,并使用蜂群遗传算法求解方案。用各零件长度的一个排列作为一个染色体,每个零件的长度作为染色体的一个基因,根据蜂群原理设置两个不同的种群,种群1用于全局搜索,种群2用于局部搜索。实验结果表明,该模型具有一定的实用价值。     

基于改进基因算法的海洋平台巡检机器人路径规划

传统遗传算法最优路径搜索效率相对较低,容易产生无实际意义个体。为此,在遗传算法选择操作中引入邻域搜索算法,提高算法的局部搜索能力,调整可变长度染色体邻接点交叉算子进化操作,避免生成间断路径。同时,在变异操作中引入多样性约束与改进的A*算法,提高遗传算法前期搜索效率。最后,在适应度函数中考虑路径长度、安全性和移动代价,生成的路径远离障碍物并在一定程度上降低转弯次数。实验证明,改进后的遗传算法在多障碍物环境下的路径规划过程中提高了搜索效率,更有利于找到实际应用中的最优解。     

基于TS-GA的LS-SVM参数优选?

将禁忌搜索和遗传算法相结合,提出一种改进的最小二乘支持向量机(LS-SVM)参数优选方法。利用自适应遗传算法进行全局搜 索,使用禁忌搜索进行局部寻优,由此提高求解速度和解的精度。采用某冶炼厂净化工段的现场数据建立模型进行仿真实验,结果表明,该方法能使LS-SVM模型具有较好的泛化能力,模型精度满足工艺要求。     

基于蚁群的数据点NURBS曲面快速拟合研究

研究数据点的NURBS曲面拟合问题,提高拟合速率。针对所要拟合的数据点分布散乱,传统的基于遗传算法多次迭代,造成曲面拟合速率不高的问题。为解决上述问题,提出一种基于蚁群的数据点NURBS曲面拟合算法。通过采用蚁群寻址算法搜索出控制顶点和边界数据点集,计算曲面的权因子后完成NURBS曲面的拟合,并使用蚁群算法对拟合曲面进行优化,避免了传统方法多代遗传迭代造成的拟合速率不高的问题。实验表明,这种方法能够快速完成散乱数据点的NURBS曲面拟合,并且具有一定的拟合效率,取得了满意的结果。     

车灯线光源优化设计及其反射光亮区的计算机模拟

文章以汽车的一种典型车头灯的线光源优化设计为例,建立了满足具体设计规范的线光源优化设计的非线性规划模型。将线光源离散化为点光源,采用数值方法求出了该模型的最优解。根据所建的模型,用计算机模拟了线光源反射光在测试测试屏上的亮区形状和亮度。     

基于遗传算法的GMDH网络模型及其应用

传统的数据处理群方法(Group method of data handling,GMDH)在结构上具有自组织和全局选优的特性,非常适合进行非线性数据的拟合.但由于在传统GMDH网络建模是用最小二乘法来辨识参数,常常使得模型预测效果不理想.遗传算法是一种有效的搜索和优化方法.它具有自适应搜索、渐进式寻优、并行式搜索、通用性强等特点,论文将遗传算法引入GMDH网络,用遗传算法辨识部分描述式的系数,建立了基于遗传算法的GMDH网络模型.并将该模型应用于一组实测时间序列的预测研究.计算机仿真结果表明,模型预测效果令人满意.     

自由曲面前照灯近光配光的计算机仿真分析

汽车前照灯防眩日技术是影响汽车行驶安全的一个关键技术,同时,它又是一个目前尚未很好解决的世界难题。该文分析了自由曲面前照灯的发展背景,阐述,ECE法规对前照灯近光配光的要求,对光线追踪原理进行了理论探讨。利用ReflectorCAD软件反求出了自由曲面反光镜的三维模型,然后,通过TracePro软件建立线光源的仿真模型,对光线进行追踪,最终仿真出了自由曲面反光镜在25m外配光屏上的实际配光效果。     

Real-Time Glints Rendering With Pre-Filtered Discrete Stochastic Microfacets

Many real-life materials have a sparkling appearance. Examples include metallic paints, sparkling fabrics and snow. Simulating these sparkles is important for realistic rendering but expensive. As sparkles come from small shiny particles reflecting light into a specific direction, they are very challenging for illumination simulation. Existing approaches use a four-dimensional hierarchy, searching for light-reflecting particles simultaneously in space and direction. The approach is accurate, but extremely expensive. A separable model is much faster, but still not suitable for real-time applications. The performance problem is even worse when illumination comes from environment maps, as they require either a large sample count per pixel or pre-filtering. Pre-filtering is incompatible with the existing sparkle models, due to the discrete multi-scale representation. In this paper, we present a GPU-friendly, pre-filtered model for real-time simulation of sparkles and glints. Our method simulates glints under both environment maps and point light sources in real time, with an added cost of just 10 ms per frame with full high-definition resolution. Editing material properties requires extra computations but is still real time, with an added cost of 10 ms per frame.     

基于帧间灰度变化分析的在线光源位置计算

针对机器视觉系统在实际生产中光源位置无法事先确定的问题,提出一种基于帧间特征区域灰度形态分析的在线光源位置计算方法。首先基于灰度分布来确定一特征区域作为参考点,然后运用块匹配算法确定相邻两帧中特征区域的位置变化,之后结合光照模型建立灰度和几何位置之间的关系,运用线性回归对联立方程组进行求解,最后得到光源位置。实验结果表明：光源位置的计算结果与实际所测的距离相比,误差在5%之内。所提算法已被应用于实际生产,具有较好的计算精度和实时性。     

基于标志点注册及探测球的光源追踪算法

增强现实系统中,解决虚拟物体表面光照情况与真实环境匹配问题关键的一步是进行光源追踪。基于标志点注册及具有漫反射特性的探测球提出一种光源追踪算法。该算法仅对一幅被单一光源照射的标志立方体和探测球图像进行分析,利用图中标志点确定探测球相对照相机的位置、姿态关系,利用探测球表面的亮度信息推算光源向量。该探测球图像要进行一系列图像处理程序,其中等亮度线的提取及拟合是关键步骤。实验结果表明,本文算法能够达到预期效果,较好地实现了光源追踪,适用于各种位置的单一光源照射情况及基于标志点注册的增强现实系统。     

SECANT-FUZZY LINEAR REGRESSION METHOD FOR HARMONIC COMPONENTS ESTIMATION IN A POWER SYSTEM

In order to avoid unnecessary damage of electrical equipments and installations,high quality power should be delivered to the end user and strict control on frequency should be made, Therefore, it is important to estimate the power system's harmonic components with higher accuracy. This paper presents a new approach for estimating harmonic component in a power system using secant - fuzzy linear regression method. In this approach the non - sinusoidal voltage or current waveform is written as I linear function. The coefficient of this function is assumed to be fuzzy number with a membership function that has center and spread value. The time dependent quantity is written as Taylor series with two different time dependent quantities. The objective is to use the sample obtained from the transmission line to find the power system harmonic components and frequencies. We used an experimental voltage signal from a sub power station as a numerical test.     

Geometrical considerations on the directivity of reflected light from a paraboloidal mirror

A divergence angle of the light emanated from an optical source composed of a source of light with finite size and a paraboloidal reflector is analyzed on the basis of geometrical considerations. The divergence angle distributions of the reflected light rays from each reflection point on the paraboloidal mirror are numerically calculated as parameters of the shapes of a lamp arc body and a paraboloidal reflector. It has been found from the analyses that the divergence angle can be reduced by prolongation of the optical path length PO to the reflection point P on the paraboloidal mirror from the focal point O of it, at which the center of the extent of the arc is located. A new approach different from conventional one to reduce the divergence angle of the light rays emanated from the optical source is proposed. The new configurations of the optical source composed of a source of light with finite size and a paraboloidal reflector or a spheroidal converging reflector are shown and discussed.     

Optimization management of hybrid energy source of fuel cell truck based on model predictive control using traffic light information

Energy optimization management can make fuel cell truck (FCT) power system more efficient, so as to improve vehicle fuel economy. When the structure of power source system and the torque distribution strategy are determined, the essence is to find the reasonable distribution of electric power between the fuel cell and other energy sources. The paper simulates the assistance of the intelligent transport system (ITS) and carries out the eco-velocity planning using the traffic signal light. On this basis, in order to further improve the energy efficiency of FCT, a model predictive control (MPC)-based energy source optimization management strategy is innovatively developed, which uses Dijkstra algorithm to achieve the minimization of equivalent hydrogen consumption. Under the scenarios of signalized intersections, based on the planned eco-velocity, the off-line simulation results show that the proposed MPC-based energy source management strategy (ESMS) can reduce hydrogen consumption of fuel cell up to 7\% compared with the existing rule-based ESMS. Finally, the Hardware-in-the-Loop (HiL) simulation test is carried out to verify the effectiveness and real-time performance of the proposed MPC-based energy source optimization management strategy for the FCT based on eco-velocity planning with the assistance of traffic light information.     

A method to generate soft shadows using a layered depth image and warping

We present an image-based method for propagating area light illumination through a layered depth image (LDI) to generate soft shadows from opaque and nonrefractive transparent objects. In our approach, using the depth peeling technique, we render an LDI from a reference light sample on a planar light source. Light illumination of all pixels in an LDI is then determined for all the other sample points via warping, an image-based rendering technique, which approximates ray tracing in our method. We use an image-warping equation and McMillan's warp ordering algorithm to find the intersections between rays and polygons and to find the order of intersections. Experiments for opaque and nonrefractive transparent objects are presented. Results indicate our approach generates soft shadows fast and effectively. Advantages and disadvantages of the proposed method are also discussed.     

Design of a 10 W high‐efficiency balanced power amplifier using a combination of load‐pull and load‐line methods for ISM band

In this article, a 10 W power amplifier has been designed and constructed at 2.4 GHz. The source and load‐pull impedance data published by the manufacturer at a nearby frequency of 2.5 GHz have been adopted to power match the transistor at the intended design frequency. For this purpose, the linear model of the GaN transistor has been derived from the S‐parameter data. The load‐line at the dependent current source plane and the impedance at the intrinsic gate‐source capacitance have been simulated in the presence of the source and load‐pull impedances at 2.5 GHz. The extracted impedances have been retained in the design of the power amplifier at 2.4 GHz. In a novel approach, the input and output matching circuits interacted with the linear model of the transistor to provide the same load‐line conditions at the virtual drain plane and the intrinsic gate‐source capacitance plane. In contrast to conventional load‐pull methods that give no information about the harmonic terminations, harmonic terminations can be easily controlled in this method. The insight into the transistor linear model allows the harmonic terminations at the virtual drain plane to be set to low values for proper class‐B operation.     

Shading with Curve Light Sources1

A new shading model for curve light sources is presented. It accounts for both diffuse reflection and specular reflection of the illuminated surface. By regarding a linear light source as a directional quadrilateral light source with very small width, a simple formula is derived first for calculating the diffuse reflection component due to the illumination of the linear segment. The diffuse reflection of the surface by direct illumination of a curve light source is then evaluated by approximating the curve light with a series of linear segments. The specular reflection component due to a curve light source is represented by an integration taking Phong's specular model as the kernel and evaluated by summing the contributions from the linear segments. Finally, an efficient shadow detection algorithm for curve light sources is proposed. The images rendered with the shading model are very photo-realistic.