共查询到20条相似文献,搜索用时 93 毫秒
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在数控机床手工编程过程中,零件几何元素基点的坐标计算是编程的基础工作之一。基点的坐标用解析几何的方法来计算费工费时,准确性不高。若用AutoCAD的坐标标注功能或点的坐标查询功能来处理零件几何元素基点的坐标则非常方便。其方法如下: 相似文献
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阐释了数控车削编程过程中数值计算的基本方法,介绍了关于基点、节点计算的几种方法:手工计算法(三角函数法,相似三角形法,联立方程组法),软件辅助法,宏程序法。重点说明了手工计算法在数车编程中的实用性。 相似文献
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设计仿形靠模轮廓曲线常用方法有作图法与计算法。计算法过程烦琐,需要计算机辅助编程完成,而传统作图法又具有误差大、精度不高的问题。以某一生产零件为例,利用Pro/E软件将作图法融入其中获得仿形靠模理论轮廓曲线的坐标,并生成较高精度的仿形靠模理论轮廓曲线及其实体,提高了仿形靠模的设计精度与效率。实践证明,这是一种有效的方法。 相似文献
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机械零件是由有限个基本几何体组成的,几何体相交所形成的相贯线一般用作图法求解.作图法的特点是形象直观,但精度较差,用数控机床加工机械零件时,需精确求出相贯线上各点的坐标.因此,作图法就不能满足要求,本文用切平面法使相贯线的求解转化为一系列平面曲线交点的求解;而平面曲线交点求解用 CL 公式(交点统一公式),既简单方便又具有很高的精度,它为三维数控自动编程系统的图象识别与输入参数研究建立了算法基础.一、机械零件基本曲面的标准式方程 相似文献
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机床导轨直线度误差的确定,目前普遍采用作图法和计算法。作图法的优点是;能直接观察出导轨直线度误差曲线中最凸和最凹部位,并能直接读出误差值。但作图法常常受作图工具及表格纸的限制,特别在精密机床中,直线度的要求较高,当误差值与其规定要求接近时,由于作图和视力观察所产生的偏差,往往无法确定是超差,还是在要求范围之内。而计算法不受这些限制,并能精确地算出误差值,因此计算法的应用越来越普遍。 用计算法确定导轨直线度误差,过去大多是采用先算出每一档相对于导轨误差曲线两端连线的偏差值,在各偏差中寻找最大值和最小值,然后将它… 相似文献
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提出基于AutoCAD软件的确定冲模压力中心的计算机作图法 ,这种方法理论严谨 ,结果准确 ,比原有的计算法和作图法简捷、快速 ,具有应用推广价值 相似文献
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通过实例分别介绍了基点选择技巧、修剪命令中边界选择技巧,并对绘图命令进行了分析和比较,采用适当的技巧对某些压图形的绘制可以起到事半功倍的效果。 相似文献
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根据运动的合成与分解原理 ,将移动从动件相对于凸轮的复杂平面运动分解为简单的往复运动和定轴转动 ,建立定坐标系和动坐标系 ;然后求出凸轮的理论轮廓和实际轮廓相对于动坐标系的直角坐标方程 ,最后采用坐标旋转变换就得到了凸轮的理论轮廓和实际轮廓相对于定坐标系的直角坐标方程 ,从而为凸轮的设计提供了一种简便实用的新方法 相似文献
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O. Ju. Smirnov 《Instruments and Experimental Techniques》2003,46(3):327-344
The energy and spatial resolution of a large-volume liquid-scintillator detector has been investigated. The relations have been derived, which allow the energy and spatial resolution of the detector to be estimated without modeling. The calculations involve the light-collection functions of the detector obtained either by the Monte Carlo method or in the measurements taken with radiation sources. The relations are verified with the experimental data of the CTF (Counting Test Facility) detector, which is a prototype of the new Borexino detector for solar neutrinos. An event reconstruction technique using charge and time data from the photomultiplier tubes (PMTs) is analyzed with the help of these relations in order to improve the detector resolution. Algorithms for the energy and coordinate reconstruction of individual events are presented. 相似文献
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为了提高大型结构体表面裂缝检测的效率,提出了一种基于图像处理技术和坐标映射相结合的定位方法。该方法首先在序列图像中抽取清晰度最高的一帧,应用Retinex算法对光照引起的亮度不均进行补偿。然后将提取的标志点图像坐标映射到观测坐标系下,根据标志点的观测坐标和世界坐标计算两坐标系间的映射关系。再根据形态学图像处理中的凸壳、像素化、细化算法提取裂缝的图像坐标;如果观测新裂缝,则将裂缝图像坐标映射到世界坐标系下;如果观测历史裂缝,则将该条裂缝的世界坐标映射到当前观测坐标系下,并计算该条历史裂缝当前的观测角度,从而实现裂缝的空间定位。经实验证明,该方法高效、准确、便捷,16 s内可实现自动定位,且偏差不大于0.07°。 相似文献
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Point coordinate measuring instruments are applied in the geometric measurement of parts. In this instrument, ultrasonic waves are used for measuring distances using a method similar to the time-of-flight method. For improvement of the measurement resolution, an accurate value of the speed of sound is enhanced by using a phase-locked loop (PLL) circuit to generate a reference signal; this signal is dependent on the variation of the speed of sound. To measure the coordinate of a point, an ultrasonic signal is produced with a wireless transmitter on the surface of a part. The waves are received by a set of three ultrasonic receivers located at the corner of the room. By counting the pulses of that signal within a transmit-to-receive period, the distance between each pair of transducers can be determined. By increasing the coefficient of the frequency divider in the PLL, the output frequency increases and the resolution improves. 相似文献
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V. M. Aulchenko D. N. Grigor’ev V. V. Zhulanov V. D. Kutovenko A. A. Talyshev V. M. Titov 《Optoelectronics, Instrumentation and Data Processing》2016,52(1):101-106
This paper describes the structure, operation algorithm, and circuitry of the recording channel of a multi-channel coordinate X-ray detector with a microsecond time resolution for studying the dynamics of density distribution in objects under pulsed loading. A method for fast automatic real-time control of the channel sensitivity is proposed. 相似文献
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Design methods for six-degree-of-freedom displacement measurement systems using cooperative targets 总被引:1,自引:0,他引:1
Six-degree-of-freedom displacement measurement systems generally employ various kinds of cooperative targets, and calculate displacement from the coordinate values of reflective rays. To improve the performance of measurement systems, a new design methodology is required, which considers the relationship between each axial output and the coordinate values, Jacobian matrix. Several performance indices are derived from Jacobian matrix and the design parameter values are determined through the optimization process. In a design example, the improvement of performance is verified by evaluating resolution, accuracy and crosstalk. The newly designed measurement system shows a maximum error of ± 0.5 μm for translation and ± 2 arcsec for rotation. 相似文献