基于图像信息的微小型飞行器飞行测高方法

微小型飞行器飞行高度的实时测量是实现其自主飞行的关键技术之一。为了准确快速地获取微小型飞行器的飞行高度参数,提出了一种新的稳健的利用图像信息获取微小型飞行器飞行高度的方法。此算法首先使用光学理论和几何学理论推导出了飞行高度的计算公式,综合运用Harris角点检测算法和区域灰度算法得到图像间的匹配角点,并使用分割区域法得到图像之间的关键点。最后通过计算关键点在图像中的位移情况,计算出飞行器当前的高度值。飞行实验表明,这种测量算法可以实时获得飞行器的高度,精度满足飞行器平稳飞行的需要。

Abstract：

Flight height is one of key technologies for micro aerial vehicle （MAV） flight autonomy.In order to get the MAV flight height accurately and quickly,a new robust flight height measurement algorithm was proposed.In the algorithm,the height was deduced from optical theory and geometry theory,and a matching corner points set was obtained by Harris corner detector and regional gray method.And then,the key points were got using the segmentation area method.In the end,the current flight height was obtained by computing the displacement of the key points in the images.The flight experiment shows that flight height measurement is real-time,and it meets the stable flight control requirements for the MAVs.     

一种新型微惯性测量组合布局误差模型的建立与仿真分析

根据一种适合于高转速载体的微惯性测量组合布局方案,在考虑载体质心和惯性测量组合中心不重合的情况下,建立了具有惯性器件安装方位误差因素的数学模型,并进行了仿真,得到了相应的误差曲线。解决了无陀螺惯性测量系统解析出的角速度比陀螺输出的角速度精度低,误差随时间严重发散的问题,提高了系统精度。

Abstract：

According to a MEMS-IMU configuration that suits high rotation vehicle measure,a mathematic model with the position error was established according to the non-coincidence of the centroid of body and the centric of inertial measurement,the model simulation was completed and the error curve was obtained.The scheme could not only solve the problem that low precision of gyroscope free measurement system compared with conventional gyro measurement system,but also the divergence of error with the time.Therefore,the calculation precision could be improved.     

非饱和土壤季节性冻融过程的仿真分析

建立了农田在自然条件下的垂向一维冻土-非冻土系统的水热耦合迁移模型,采用Newton-Naphson迭代法进行求解,通过模拟与实测结果对比,取得较好效果,验证了模型的可用性。在此基础上用该模型对季节性冻融期土壤冻融过程进行了仿真分析,研究了土壤季节性冻融特点,探讨了影响土壤冻融过程的主要因素,即气温和累积负温,仿真结果可为冬春作物的播种、预防冻害等提供科学依据。

Abstract：

A coupled moisture and heat transfer model for natural farmland in one-dimensional vertical frozen-unfrozen soil system was established,and Newton-Naphson iterative technique was used to solve the model.Better results were got through the comparison of simulated and measured results which verified the model＇s availability.Based on this,the model was used to emulate the process of soil freezing and thawing in seasonal freezing and thawing period,and the soil’s seasonal freezing and thawing characteristics was researched,and then the air temperature and soil cumulative negative temperature two main factors were investigated which effected process of soil freezing and thawing.Results of emulation can provide a scientific basis for winter or spring crops sowing and preventing crops from freeze injury.     

车辆半主动悬架系统模糊神经网络控制研究

悬架系统对车辆平顺性具有重要的影响,通过预瞄控制在后轮处提前预测路面不平度,用于解决半主动悬架模糊神经网络控制存在的时滞问题。建立了1/2车辆模型和路面输入模型,设计了基于预瞄控制的半主动悬架模糊神经网络控制结构,并进行了白噪声输入仿真分析。结果表明：预瞄控制后的车身加速度峰值和标准差比被动系统分别减少了61.61%和44.28%,比模糊控制的悬架系统分别减少了21.23%和21.20%;预瞄控制后的质心加速度峰值和标准差比被动系统分别减少了35.21%和57.81%,比模糊控制的悬架系统分别减少了7.83%和20.10%。后轮处车身加速度和质心垂直加速度均有明显减小,较好改善了悬架系统适应道路的性能,有效缓和了车辆的振动和提高了汽车的行驶平顺性。

Abstract：

Suspension system has important effect on vehicle ride comfort.Wheelbase preview control method could be used to forecast the road surface roughness at the front wheel,and to be used to solve the delay problem in fuzzy neural network controlled semi-active suspension system.The 1/2 vehicle model and road input model was established,and the fuzzy neural network control structure based on wheelbase preview control theory was designed.The white noise input simulation was carried out and the results show that the peak and standard deviation of body acceleration are separately decreased by 61.61% and 44.28% compared with passive suspension system,and are 21.23% and 21.20% compared with fuzzy controlled suspension system;on the other hand,the peak and standard deviation of vertical acceleration at CG are separately decreased by 35.21% and 57.81% compared with passive suspension system,and are 7.83% and 20.10% compared with fuzzy controlled suspension system.The body vertical acceleration at rear wheel and the vertical acceleration at CG are significantly decreased to adapt to the suspension performance,which helps to effectively easy the vehicle vibration and to improve the vehicle ride comfort.     

功能性电刺激脚踏车训练系统建模及仿真分析

针对FES脚踏车训练系统建立数学模型并对模型进行仿真。该系统模型由模式发生器,电刺激关节力矩模型及人机动力学模型组成。根据关节伸展弯曲时,脚踏车曲柄对应角度和速度关系及三组肌肉群的状态,建立模式发生器模型。对腿部肌肉群刺激时序优化得到最终刺激模式。通过计算肌肉在电信号刺激下的肌肉激活度、最大肌肉力、肌肉力长度特性及肌肉力速度特性建立电刺激肌肉力模型,得到电信号刺激肌肉时产生的肌肉力大小及肌肉力在关节处的合力矩。根据拉格朗日方程和关节力矩建立人机动力学模型。采用典型人体数据,以Simulink为仿真平台,通过差分、迭代等方法对系统模型求解,得出刺激信号与肌肉、关节及曲柄的动力学关系。以脊髓损伤患者对训练系统进行实验,对比曲柄处合力矩与曲柄角度关系验证脚踏车系统模型方法正确可行。

Abstract：

Aiming to study FES cycling system,the mathematics model and simulation were presented.The model includes pattern generator,stimulation-joint torque and man-machine kinetic model.Based on three muscles group state,the crank angle and velocity when the joint extending and flexing,the pattern generator model was built.Optimizing the stimulative time sort,the final stimulative pattern was explored.By calculating muscle active,muscle maximal force,the characteristic of muscle force-length and muscle force-velocity under signal stimulation,the electric stimulating muscle model,stimulative muscle force and the torque on the joint can be got.Based on Lagrange equation and joints torque,the man-machine kinetic model was built.Using typical body data and Simulink platform,the relationship of kinetics among the stimulation signal,muscles,joints and crank was found using the method of iteration and difference to solve the system model.From the experimental data of SCI patient on the system,comparing the results of crank torque and crank angle between simulation and experiment,it is showed the model of FES cycling is feasible.     

矩形体充磁线圈有限元分析

提出五金工具充磁线圈结构及参数的设计方法,基于有限元方法与Ansoft Maxwell 3D工具,建立了矩形体充磁线圈的仿真模型,实现对线圈内部Z轴线、XOY0端面、XOY1中心平面,以及纵向中心剖面XOZ0、YOZ0上各点的磁场强度的仿真,详细分析了仿真结果,并与实际测试数据进行对比分析。研究结果表明,所设计的仿真方案可较为全面地描述线圈内部各点的磁场强度,获得的各相关点的仿真数据与实际测试结果具有一致性。仿真研究对实际线圈结构与参数的设计具有指导意义,设计所获得的结果达到充磁工艺预期要求。

Abstract：

The way to design magnetic charging coil for hardware tools was offered.Based on the finite element method and Ansoft Maxwell 3D,the simulation model was established,and the magnetic densities of the different points inside the coil located in the Z-axis,the terminal cross section XOY0,the centric cross section XOY1,as well as the vertical section XOZ0 and YOZ0 were investigated respectively in detail.The simulation results were analyzed,and also compared with the actual measurements.The conclusion of the research shows that the magnetic density of each point inside the coil can be completely described with the given scheme,and the simulation data achieved have the consistency with the actual measurements.The research also indicates that the simulation study has the significance to the design of the structures and the parameters of magnetic charging coil.The expected polytechnic demands of magnetic charging can be met by the research results.     

冲击射流的间断有限元仿真研究

采用间断有限元方法对轴对称可压缩Euler方程组进行数值离散,并对非稳态垂直冲击射流进行了仿真模拟。计算结果表明,采用该方法能够较好地捕捉到起始冲击波在平板上反射后形成的曲面激波、马赫反射以及三波交点等复杂流场波系结构;随着时间的发展,冲击平板中心区域有明显的回流现象;平板表面的压力系数分布曲线与实验测量结果吻合较好;表明该方法是有效的,为冲击射流的数值仿真提供一种新的手段。

Abstract：

Unsteady impinging jet was simulated numerically using discontinuous finite element method which discretized axisymmetric compressible Euler equations.The computed results show that the complicated shock wave structures of interest including bowed shock waves,Mach reflected wave and the triple point are well captured using this method.Recirculating flow near the center impinging zone of surface can be observed obviously with the lapse of time.Comparisons of Surface pressure coefficient distribution showed better agreements between the computed results and experimental measurements,which indicate that this method is efficient and provide a new means for simulating the impingement jet.     

求解动态优化问题的分叉PSO算法

近些年来,求解动态环境中的优化问题已经逐渐成为进化计算领域的一个新的研究热点。为了改善一般PSO算法求解这种动态优化问题的能力,现提出了一种采用分叉策略的多粒子群PSO算法。该算法能够利用一个较大的主粒子群不断搜索问题适值曲线上新的峰,而利用从主粒子群中分离出来的若干个较小的子粒子群去跟踪已经发现的峰的变化。通过对一组标准动态测试函数的实验,能够证明所提出的算法在动态环境中具有较强的鲁棒性和适应性。

Abstract：

Recently,there has been increased interest in evolutionary computation algorithms applied into dynamic environments since many real-world optimization problems are time-varying.Inspired by a forking mechanism,a new multi-swarm optimization algorithm （Forking PSO,FPSO） was proposed to enhance simple PSO’s search in dynamic landscape.In FPSO,a larger main swarm is continuously searching for new peaks and a number of smaller child swarm,divided from main swarm,are used for tracking the achieved peaks over time.Experimental study over a benchmark dynamic problem suggests that the proposed algorithm has much stronger robustness and adaptability in dynamic environments.     

Hilbert Problem 15 and Ritt-Wu Method (II)

This paper proves three statements of Schubert about cuspal cubic curves in a plane by using the concept of generic point of Van der Waerden and Weil and Ritt-Wu methods. They are relations of some special lines: 1) For a given point, all the curves containing this point are considered. For any such curve, there are five lines. Two of them are the tangent lines of the curve passing through the given point. The other three are the lines connecting the given point with the cusp, the inflexion point and the intersection point of the tangent line at the cusp and the inflexion line. 2) For a given point, the curves whose tangent line at the cusp passes through this point are considered. For any such curve, there are four lines. Three of them are the tangent lines passing through this point and the other is the line connect the given point and the inflexion point. 3) For a given point, the curves whose cusp, inflexion point and the given point are collinear are considered. For any such curve, there are five lines. Three of them are tangent lines passing through the given point. The other two are the lines connecting the given point with the cusp and the intersection point of the tangent line at the cusp and the inflexion line.

     

遗传算法在企业铁路取送调车作业优化中的应用

如何合理安排企业铁路取送车作业是企业铁路调车作业中的一个重要环节.本文针对调车作业方式＂送取分离＂的企业铁路货运站,参照3车列的取送车仿真时序,建立了取送车作业优化问题的数学模型.同时,提出一种带启发式知识的进化增强型遗传算法用以求解这类大规模组合优化问题.算法一方面通过启发式知识产生优良个体并有效保存,加速算法寻优;另一方面通过有效的交叉和变异操作保证算法的多样性,避免算法早熟;从而最终有效提高算法的寻优效率.实例计算结果验证了模型和算法的有效性和工程实用性.     

基于幂函数控制指令的垂直飞行仿真性能分析

基于模态直接切换的飞行高度控制方法,在输入控制指令后,存在控制量输出震荡,甚至发散的问题。幂函数符合飞行高度指令变化规律,以此为原型函数,推导给定高度,当前高度和垂直速度之间的关系,将这一变换关系作为垂直速度控制回路的输入指令,设计了平稳控制系统,该系统不需要进行控制模态切换,就可以实现飞行高度保持,以及飞行高度的改变。通过A320飞行仿真平台对设计的平稳控制系统进行性能分析,结果表明该系统可以实现高度的平稳控制,且稳态误差得到了很好抑制。     

竞争环境下考虑供应链透明度的大数据投资决策

针对供应链中的大数据投资决策与激励问题,考虑两个制造商通过大数据投资预测需求,并通过集团采购获取产品部件,进而展开产品数量竞争.从纵向与横向刻画供应链透明度,构建分散决策下的大数据投资决策模型,分析供应链透明度、竞争强度和大数据技术水平等因素对均衡结果的影响,并与集中决策进行绩效对比.研究发现:纵向与横向透明对大数据投资均有负效应,因而'会降低其可行性和投资水平;当竞争足够激烈时,纵向透明的负效应小于横向透明,且能抑制横向透明的负效应,从而产生正的溢出效应;竞争导致大数据投资过度,横向透明导致大数据投资不足,而纵向透明却可能在竞争强度与大数据技术水平均较低或较高时实现大数据投资最优.     

广义螺旋面加工三维高精度仿真研究与应用

以楔横轧模具孔型上异型螺旋面为代表的广义螺旋面,因结构和加工方法的特殊性,其加工过程三维瞬态仿真是仿真研究的难点与亟待解决的课题。紧扣车削成形特点,建立了适合仿真图像显示的"主从准线"数学模型;提出了能有效降低数据冗余量、提高图形表达能力的"动态网格"数据结构;并在此基础上研究了一套仿真算法形成了一个完整的仿真体系,高效、高置信度的实现了广义螺旋面加工过程的仿真。     

可持续发展下的IS-LM-SD曲线研究

研究了在可持续发展下的产品市场、货币市场以及生态环境市场的共同均衡问题.主要研究结论为:第一,存在一条右向下的上凸的可持续发展曲线,并可以实现产品市场、货币市场和生态环境市场的同时均衡.在此条件下的三个市场由非均衡状态到均衡状态的收敛速度高于不考虑可持续发展下的收敛速度;第二,为实现可持续发展,扩张的货币政策或紧缩的财政政策必导致产量水平的提高;反之,为实现可持续发展,紧缩的货币政策或扩张的财政政策必导致产量水平的下降;第三,扩张的财政政策或扩张的货币政策,同样可采取相应较宽的生态环境政策以实现均衡.在此条件下,均衡产量水平均较原均衡点为高;反之,紧缩的财政政策或紧缩的货币政策,可采取较紧的生态环境政策以实现均衡.在此条件下,均衡产量水平均较原均衡点为低.     

舰船喷水推进系统数学建模及动态工况仿真研究

对舰船喷水推进系统而言，动态工况下喷水推进泵的工作安全性是一个十分重要的研究课题，而控制系统参数设定的正确与否将在很大程度上决定动态工况下喷水推进泵能否安全可靠工作。首先建立了适用于系统动态工况仿真的舰船喷水推进系统数学模型及仿真模型，然后从避免喷水推进泵在动态工况过程中工作曲线进入使用限制区域的角度出发，重点对舰船加速和回转两类动态工况进行了仿真研究，并依据仿真结果对相应控制参数的正确设定提供指导。     

针对转台及控制器设计的虚拟样机技术应用研究

基于虚拟样机技术进行了飞行仿真转台及其控制器的设计.考虑到非线性、摩擦以及机械系统的柔性特性利用ADAMs进行具有复杂特性的虚拟样机建模.采用Solidworks进行机械部分的建立并导入ADAMS中,使机械设计和虚拟样机设计连贯有序.提出了利用虚拟样机技术代替通常的数学模型进行控制器设计及仿真实验的方案,使设计与实验结果与实际系统更加贴近.基于虚拟样机技术在更接近实际的情况下对控制性能进行检验.并且,控制器的设计可以在实际样机生产之前开始,提高了设计效率.以某单轴转台为例,详细介绍了该控制器设计及校验方法.联合仿真结果证明了方案的合理性.     

舰载导弹存放架减振装置设计与实验研究

针对舰载导弹存放架减振要求苛刻的特点,分析了高低频复合振动条件对减振器刚度的要求,得出大承重条件下难以满足低频减振要求.针对高频振动,应用金属橡胶和金属弹簧设计了一种复合减振装置,通过仿真实验验证了样机对高频振动的有效性.研制了试验样机,并进行了静态力学和动力学试验,得到减振器刚度为806.5 N/mm,系统有效隔振带12.78Hz,满足系统减振要求;同时分析了动力学试验加速度传递曲线双共振峰的原因是由于增加了俯仰自由度.     

垂直发射武器与舰炮武器火力交叉的判断

针对现代水面舰艇舰载武器的发展趋势以及垂直发射武器的外弹道散布特性,研究解决垂直发射武器系统与舰炮武器系统之间火力交叉的判断求解问题。描述了垂直发射武器弹道散布体模型。在导弹的垂直上升段借鉴舰炮武器火力交叉判断模型进行判断;在转弯段利用迭代法求解理想弹道与舰炮瞄准轴线最短距离,并判断是否发生火力交叉。