用户自定义建模离线编程与仿真平台设计

离线编程及仿真系统作为是工业机器人研究领域最活跃最前沿的研究方向之一,但目前存在的该类型系统仍运行于单一系统或平台下,所能加载的机器人类型限于某一种或某一公司的某种型号。基于此提出了一个基于Qt框架的离线仿真和编程系统,通过设计规划了图形库系统并定义了相应的装配文本格式,实现了当前广泛使用的6旋转自由度工业机器人的用户自定义加载,还分别对六自由度工业机器人运动学进行了分析,并介绍了系统的总体结构,还描述了指令编译系统。最终的仿真结果证明系统较好的满足了具备柔性化建模的6旋转自由度工业机器人离线编程及仿真平台的要求。     

基于C#的仿真示波器设计与实现

开发了仿真示波器和仿真实验程序,使示波器使用更加简单方便,激发了学生学习热情,提高了实验教学质量.通过采用仿真实验这一先进的教学手段,学生更快掌握实验仪器使用,更好理解实验内容,同时方便了实验维护和升级,节省了实验经费.     

无人机视景仿真平台设计与实现

在Visual Studio开发环境下,利用DirectX 9.0设计并实现了无人机视景仿真平台;仿真平台的通信系统可通过多种通信方式获取仿真数据;根据DirectX中3D仿真技术特点以及无人机视景仿真需求,设计并实现了无人机在DirectX世界坐标系中的姿态变换方法;根据无人机视景仿真特点,设计了虚拟摄像机视场角控制方法;仿真平台仿真效果生动逼真且运行稳定,具有很强的实用价值,在无人机研制过程中起到了重要作用。     

一种光伏控制器的仿真设计实验

设计了一个基于单片机的仿真设计实验。采用MPPT算法,通过Proteus、Multisim、Altium Designer等电路进行了仿真软件验证,设计并实现了一种基于计算机仿真的光伏控制器,从而有效实现太阳能辐射的最大功率点跟踪。     

一种激光搜索跟踪系统的设计和仿真

介绍一种用于空间交会的激光搜索跟踪系统，该系统设计能够满足雷达、导航和通信的要求。通过对系统组成和工作流程等的分析，建立追踪航天器和目标航天器的激光搜索跟踪系统模型，该模型能够完成系统指标的计算和动画演示。     

基于四元数方法的光学系统可视化建模与仿真

以四元数方法在光线传输计算中的应用为理论基础，推导出一套基于四元数方法的光线传输运算公式，采用Visual C++ 和OpenGL建立一个光学系统可视化仿真平台，用于振动环境下光学系统的辅助分析。给出光线追迹运算流程与图形可视化实现关键技术，并对仿真平台的整体结构与功能进行了介绍。通过对某光学系统的仿真分析，成功仿真出图像经过光学系统产生的枕形畸变，证明四元数方法在光线传输运算中的正确性与可行性，为复杂光学系统的空间光线传输计算提供了另一种方法。     

一种快校正磁铁电源设计与仿真

快校正磁铁电源是光源和加速器中重要的设备。随着光源性能的提升,加速器对快校正磁铁电源的性能也提出了更高要求。为满足快校正磁铁电源性能要求和简化设计过程,开展了快校正磁铁电源控制策略和仿真研究,并提出了PI控制加二阶相位补偿的方法作为快校正磁铁电源的控制策略;利用伯德图设计快校正磁铁电源的相位补偿参数,以提高电源系统相位裕量。该方法不仅保证了电源系统工作在深度负反馈状态,而且简化了相位补偿的参数计算过程。为了验证控制策略的正确性和有效性,提出用压控电压源代替开关器件开展电源性能仿真的方法。仿真结果验证了上述控制策略的可行性和有效性,同时验证了上述仿真方法的有效性和高效性。     

卫星分系统仿真测试平台设计与实现

卫星三级测试包括设备级测试、分系统级测试和整星级测试,测试成本较为昂贵,为了达到尽早的开展分系统级测试的目的,提出了一种数字仿真环境同单机设备相结合的分系统仿真测试平台的设计方法;通过对各单机设备进行仿真建模,并依据设备间的数据交互方式进行物理实现,为单机设备构建分系统级的测试环境;解决了在缺少单机设备时无法开展分系统级测试的难题;尽早的对单机设备进行分系统级测试,可以在早期就发现单机设备存在的缺陷并进行改正,从而达到节省测试成本的目的。     

光学仿真设计与挑战性创新训练教学方法研讨

教学团队本着"理论建模、可视仿真、创新实践、前沿挑战"的培养理念,重点落实电子科技大学"应用物理强基计划"培养目标,对"光学系统设计"、"光通信技术"、"数学物理方法"等本科生专业核心课程群实施了教学模式改革.在教学手段上,将抽象、复杂、繁琐的理论模型通过三维可视化仿真,生动、形象地表现出来,使大学生更易于理解;在编程训练环节,对光学系统进行创新性设计和三维重构,培养大学生编程实践能力;在挑战性实践环节,构建光学实验的虚拟仿真平台,加强大学生创新挑战思维的启发.该教学方法对培养具有编程仿真能力和挑战性创新实践能力的研究型人才取得了显著教学效果,为国家战略需求领域科学与工程技术研究提供人才储备.     

燃气泄漏报警系统仿真设计与实验

给出以单片机为核心的燃气泄漏报警系统仿真设计与实验的完整流程:包括设计要求、总体方案、Proteus环境下的原理图设计及软硬件仿真调试实验等。可以为温度、压力、光强等其它常见物理量测量控制系统仿真设计与实验提供参考。     

飞机跑道胶痕的自动识别系统设计与实现

为了减轻机场跑道除胶工作人员的劳动强度,提高除胶工作效率,文章提出了一种基于机器视觉的胶痕自动查找和识别方法,设计了基于ARM单片机控制的图像无线采集和基于PC机控制的图像接收、图像预处理和图像识别系统。文章通过分析预处理后的数据特点,确定了基于细胞神经网络算法的胶痕识别算法,然后在MATLAB仿真环境下确定了该算法的最优模型和参数,最后在Visual C++ 6.0环境下完成了该算法的程序编译,调试并完成了对胶痕的自动识别过程。理论仿真和程序测试的结果证明了文章提出的方法在胶痕自动识别系统中的可行性,也为机场特种设备的无人化和智能化提供了参考。     

Simulation of temperature-dependent material parameters and device performances for GaInAsSb thermophotovoltaic cell

Temperature-dependent material parameters and device performances of Ga_xIn_1−xAs_1−ySb_y TPV cells applied in low temperature (800–1200 °C) radiators are simulated using the PC-1D. As is well known, the optimum bandgap (E_g) decreases towards lower radiator temperatures. So far, the lowest achievable E_g of Ga_xIn_1−xAs_1−ySb_y at 300 K is 0.5 eV. We mainly considering the Ga_0.8In_0.2As_0.18Sb_0.82 (E_g = 0.5 eV) TPV cell. The effects of doping concentration and recombination mechanisms of the emitter layer on photovoltaic conversion efficiencies (η_cel) are analyzed in detail, and η_cel can be improved by optimizing doping concentration and suppressing carrier recombination. The effects of GaSb window layer on η_cel are also presented. It shows the type-II energy-band alignment GaSb(window)/GaInAsSb(emitter) heterostructure affect η_cel mainly through V_oc. For the first time, the effects of operating temperatures on device performances are analyzed based on temperature-dependent material parameters, and the temperature coefficients of the device performances are presented.     

NQR Study of Phase Transition and Cationic Motion in 4-NH2C5H4NHBiBr4·H2O

Four ⁸¹Br NQR lines in 4-NH₂C₅H₄NHBiBr₄·H₂O were observed in the temperature range between 77 and ca. 380 K; with increasing temperatures the respective sets of higher and lower two resonance lines coalesced into single lines discontinuously at 274 K, showing the occurrence of a first-order type phase transition of this crystal. The transition was confirmed with heat anomaly on a DTA curve. Each higher and lower line of high-temperature phase is assignable to the terminal Br atoms and the bridging ones of one-dimensional poly anions (BiBr₄ ⁻) _n in the crystal structure (C2/c), which was investigated by a X-ray structure analysis at room temperature. The 1/T ₁ temperature dependence of ⁸¹Br NQR follows the usual T ² law in the temperature range between 77 and ca. 140 K, being explained by fluctuation of the EFG at Br nucleus due to lattice vibrations. The T ₁ vs. 1/T curve in the temperature range between about 160 and 190 K was describable by the exponential curves, allowing us the estimation of activation energies. These exponential behaviors of T ₁ of ⁸¹Br NQR are attributable to the fluctuations caused by the thermal motion of 4-NH₂C₅H₄H⁺ ions. Echo signals of the ⁸¹Br NQR could not be detected above 190 K owing to poor S/N with very short T ₂.     

Wave Simulation in Frozen Porous Media

We propose a numerical algorithm for simulation of wave propagation in frozen porous media, where the pore space is filled with ice and water. The model, based on a Biot-type three-phase theory, predicts three compressional waves and two shear waves and models the attenuation level observed in rocks. Attenuation is modeled with exponential relaxation functions which allow a differential formulation based on memory variables. The wavefield is obtained using a grid method based on the Fourier differential operator and a Runge–Kutta time-integration algorithm. Since the presence of slow quasistatic modes makes the differential equations stiff, a time-splitting integration algorithm is used to solve the stiff part analytically. The modeling is second-order accurate in the time discretization and has spectral accuracy in the calculation of the spatial derivatives.     

对流作用下枝晶形貌演化的数值模拟和实验研究

合金凝固过程中存在于枝晶尖端液相区的强制对流和自然对流均能改变溶质扩散层厚度,从而会对枝晶形貌产生较大影响.在元胞自动机模型基础上,耦合液体流动方程、热传导方程和溶质对流扩散方程,建立了新的计算微观组织演化的数值模型,并利用该模型研究了强制对流和自然对流对枝晶生长的影响.三维数值模拟结果再现了强制对流作用下等轴枝晶的生长过程,揭示了强制对流对枝晶生长速率和尖端半径的影响特点.同时利用该模型模拟了NH₄Cl-H₂O溶液定向凝固过程中自然对流对柱状晶生长的影响,并采用相应的实验进行验证.模拟结果与实验结果符合良好,从而证明该模型是可靠的,可推广到实际合金系中. 关键词： 元胞自动机 对流 4Cl-H₂O溶液')" href="#">NH₄Cl-H₂O溶液 定向凝固     

Simulation study of semi-superjunction power MOSFET with SiGe pillar

The feasibility of applying the semi-superjunction (Semi-SJ) with SiGe-pillar (SGP) concept to Power MOSFET is studied in this paper. The electrical performances of SGP are compared with the conventional Power MOSFET through 3D device simulation work in terms of specific-on resistance (_Ron)$\left(R_{on}\right)$, breakdown-voltage (BV  ), the effect to change the Ge mole fraction in the SGP and the thermal stabilization. The results show that the _Ron$R_{on}$ is reduced by 44% on the base of BVs   reducing only 4.8%, tradeoff _Ron$R_{on}$ vs. BV and thermal stabilization of SGP are superior to that of conventional Semi-SJ since the strain effect inducing into the SGP structure in the low power device application.     

A New Unconditionally Stable Algorithm for Steady-State Fluid Simulation of High Density Plasma Discharge

A new unconditionally stable algorithm for steady-state fluid simulation of high density plasma discharge is suggested. The physical origin of restriction on simulation time step is discussed and a new method to overcome it is explained. To compare the new method with previous other methods, a one-dimensional fluid simulation of inductively coupled plasma discharge is performed.     

Combustion synthesis of a nanoceramic and its transparent properties

La_0.1Nd_0.1Y_1.8O₃ transparent ceramics nanopowders were prepared using the combustion synthesis. To achieve such transparent ceramics, Y₂O₃ were used as matrix materials and La³⁺ and Nd³⁺ were used as dopants, polyethyleneglycol (PEG) as dispersants for the sintering under vacuum 10⁻³ Pa and 1600 °C for 6 h. The precursor and powders calcined at different temperatures were characterized using TG-DTA, XRD, BET and FESEM. The transmittance of the transparent ceramics was measured using the sub-photometer. Results showed that La³⁺ and Nd³⁺ were completely dissolved into the cubic lattice of Y₂O₃. The sizes of Y_1.8La_0.1Nd_0.1O₃ powders were uniform and spherical-like. The particle sizes of powders gradually increased with increasing the calcination temperature. The dispersant can effectively prevent the powders from the agglomeration, and the particle sizes of powders gradually increased with increasing citric acid. The transmittance of the Y_1.8La_0.1Nd_0.1O₃ transparent ceramics was close to its theoretical value (80%).     

Design and operation characteristics of a high power transverse flow pulser sustained cw CO2 laser

A transverse flow, transverse discharge cw CO₂ laser in which de discharge is sustained by employing high repetition rate high voltage pulses has been developed. Pulser sustained discharge through electrodes of innovative design provided uniform excitation at electrical input power densities more than 10 W/cc. Laser output power more than 2.5 kW was obtained in a laser gas mixture consisting of 0.5 mbar of CO₂, 16 mbar of N₂ and 38.5 mbar of He. Design details and operational characteristics of this laser are presented.