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为了探索纸张切割非接触式成像定位测量的新途径,以替代传统的接触式测量方式,提出一种利用图像分割,图像匹配和测量技术的纸张切割非接触式定位测量方法,分析和探讨涉及图像处理关键技术,并进一步分析了测量的精度和误差产生的因素。实验结果表明,该测量方法测量时间小于0.5s,测量精度为7min,从而为物体在线测量与定位提供了一种新的方案。 相似文献
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超声波小管径流量测量装置的研制 总被引:1,自引:2,他引:1
介绍了一种时差测量方法不同于传统时差测量方法的超声波小管径流量测量装置。给出了基本的测量原理及软、硬件设计。该装置由于采用了超高速数据采集系统,并利用分析采集数据的方法来确定时差,与一般的流量计相比,缩短了测量时间,提高了测量精度,具有重要的创新意义和实用价值。 相似文献
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花粉外壁纹饰特征作为衡量被子植物进化程度的参考依据之一,对其准确刻画具有重要意义。论文分析了传统测量方法的特点和不足,提出了利用图像处理技术测量花粉外壁纹饰图像的方法。该方法实现了对于花粉外壁纹饰图像快速、精确的测量。通过对实验数据的对比分析,验证了该文提出方法的可靠性。 相似文献
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面向高性能光盘盘片的轴向动态特性测量方法研究 总被引:1,自引:0,他引:1
系统研究了影响光盘机械系统轴向偏摆的各分量对总偏摆的影响,建立了光盘机械系统轴向偏摆的数学模型并进行了数值计算。根据计算结果,提出了对各测量方法的基本测量要求。分析了几种有代表性的测量方法的优缺点并重点研究了它们各自的测量精度,提出了一种全新的基于激光三角法的测量方法,最后给出了测量结果和结果分析。 相似文献
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网络控制系统的对象建模 总被引:2,自引:3,他引:2
网络控制系统(NCS)中的被控对象是包含工业控制对象和通讯网络的广义被控对象,其模型是时变不确定的,十分复杂。在考虑了单包传输、多包传输、数据包丢失、延时、随机干扰等情况下,用一种统一的形式,建立网络控制系统的模型。对广义被控对象进行分析和建模有利于网络控制系统控制器的分析和设计。在实际工程应用中在分析了NCS网络特性基础上。皆可按该方法对广义被控对象建模,然后再进行控制器设计。 相似文献
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When a plant and its controller are sufficiently linear and time-invariant so that they can be represented by transfer functions, and this plant is under classical control (meaning the controller can also be represented by a transfer function), the model-plant mismatch (MPM) that often plagues industrial processes can be written as a closed-form expression. This includes a variety of controllers, among which the ubiquitous Proportional, Integral and Derivative (PID) controller. The MPM expression can then be used to identify a representative transfer function of the “true plant” from the currently available plant model. The MPM expression works for single-input single-output as well as multiple-input multiple-output systems. The closed-loop data required for application of the expression has to be sufficiently exciting. If significant disturbances perturb the plant their values need to be available. In this article the expression is applied to industrial data to show its applicability. 相似文献
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虚拟植物生长的双尺度自动机模型 总被引:85,自引:1,他引:84
用来构造植物形态的计算机模型很多,但大部分模型用于自然景物的模拟,所研究的内容主要集中在计算机图形学方面。该文从植物学的角度出发,提出了微状态和宏状态的双尺度概念,建立了虚拟植物生长的双尺度自动机模型,该模型考虑了植物的生长机理,参数物理意义明确,结构简洁条理,形象直观,易于理解和编程实现,并且应用了符合植物顶芽和腋芽发育过程的概率模型,更适合模拟真实植物的生长过程,通过与“L系统”和“参考轴技术”这两种著名的植物生长模型的比较,以及给出了用该模型模拟植物学家提出的构造模型的例子,证明了该模型实用有效。 相似文献
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A multiinput multioutput linear time-invariant control system with a singular system matrix can be transformed in such a way that the integral of the state transition matrix can easily be calculated. Application of this transformation to the problem of discretization of a continuous-time plant and to the calculation of the time response between sampling instants of the plant with digital controller is presented. 相似文献
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核电厂高压电气断相故障,在实际电厂运行中主控室无法监测到。而现有分析仅仅是从电网设备角度分析,核电厂无法得到电网计算分析结果,是业内断相问题分析的空白。将电网断相计算分析模型与核电厂全范围模拟机系统模型集成在一起,能够从电网侧和核电厂工艺系统运行设备侧完整分析出断相后核电厂运行情况。将成熟的电网断相计算与模拟完善的模拟机软件通过接口开发,连接在一起进行多种电压等级断相故障测试是难题,通过三相电机模型开发,接口转换工具开发等处理,很好的解决了两种计算模型的接口问题,之后的断相测试结果,为核电站在断相故障发生后的快速反应提供了重要的依据。 相似文献
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Control of a linear plant, with bounded control input, may be implemented by constructing a control law generator which produces the optimal control as a function of the state variables. If the plant parameters differ from their nominal values, then maintaining optimal control by changing the control law generator is inconvenient since the control law is usually nonlinear. It is shown that in certain cases optimal control can be maintained without changing the control law generator. This is accomplished by using a linear transformation of state variables as the input to the control law generator. The variations of the plant are compensated for by changing the linear transformation. The conditions under which this is possible are established in this paper. The advantage of this system is that a change in a linear function is easier to implement than a change in a nonlinear function. It is shown how this system can be incorporated into an adaptive system which compensates for plant variations. 相似文献
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Problems associated with process control equipment, such as valves, can be very subtle and difficult to detect. However, the impact that these problems can have on the performance of a process control system can be significant. This paper explores the use of dynamic, mechanistic modelling as a tool for detecting problems associated with process control equipment and as a technique for validating that corrective action which will solve these problems before such action is applied to the plant. The paper describes a case-study application at an INEOS ChlorVinyls site in Runcorn. In this case study, a dynamic model was able to identify the cause of a serious plant problem and determine the necessary re-configuration of the plant control systems, such that plant operations were improved. 相似文献
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准确、灵活的叶片模型对植物建模具有重要的意义,但目前大部分植物叶片曲面模型没有提供足够的准确性和细节描述。为了给生成准确、细致的叶片几何模型提供灵活的方法,即首先利用B样条曲线来描述叶片的边缘轮廓和主脉;然后用Delaunay三角化方法对叶片曲面进行网格化;最后通过改进Loop细分规则的自适应细分方法来优化叶片曲面,从而为植物叶片提供了一种灵活的3维几何造型描述方法。由于B样条曲线能够很好地描述大部分植物叶子的轮廓,Delaunay三角化方法的使用又解决了包含多个裂片的叶片曲面的网格化问题,而自适应曲面细分方法则不仅使得生成的空间曲面具有更高的光滑度,同时可使得生成的叶片曲面能够进行卷曲变形。实验结果充分表明,该方法是有效的。 相似文献
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