Investigation on full distribution CNC system based on SERCOS bus

A full distribution CNC system based on SERCOS bus is studied in accordance with the limitations of traditional PC-based motion card. The conventional PC-based motion control card is dispersed into several autonomous intelligent servo-control units with the function of servo driver. The autonomous intelligent servocontrol units realize the loop control of position, velocity and current. Interpolation computation is completed in PC and the computational results are transferred to every autonomous intelligent servo-control unit by high speed SERCOS bus. Software or hardware synchronization technology is used to ensure all servomotors are successive and synchronously running. The communication and synchronization technology of SERCOS are also researched and the autonomous intelligent servo-control card is developed byself. Finally, the experiment of circle contour process on a prototype system proves the feasibility.     

一类对称Loewner矩阵及其可逆性

利用对称Loewner矩阵与有理函数插值之间的内在联系,给出一类对称Loewner矩阵非奇异的充要条件,并给出逆矩阵的明确表达式,以及满足一定条件的奇异对称Loewner矩阵的Moore-Penrose逆的明确表达式.     

一种油藏储层三维可视化散乱数据插值方法

提出一种快捷有效的确定待估点的有效样本点集的辐射吸收插值模型,该模型应用到散乱数据网格化过程中,它不但具有加权平均算法的优点,而且具有插值效率高、局部性好、易于控制、易于对数据增加约束条件等特点.辐射吸收插值模型由辐射过程、吸收过程和合成过程组成.讨论了辐射吸收插值模型的实现原理、设计过程、在油藏储层三维可视化散乱数据插值中的应用和模型特点的分析.     

Multi-Dimensional Piece-Wise Self-Affine Fractal Interpolation Model

Iterated function system (IFS) models have been used to represent discrete sequences where the attractor of the IFS is piece-wise self-affine in R 2 or R 3 (R is the set of real numbers). In this paper, the piece-wise self-affine IFS model is extended from R 3 to Rn (n is an integer greater than 3), which is called the multi-dimensional piece-wise self-affine fractal interpolation model. This model uses a "mapping partial derivative" , and a constrained inverse algorithm to identify the model parameters. The model values depend continuously on all the model parameters, and represent most data which are not multi-dimensional self-affine in Rn . Therefore, the result is very general. The class of functions obtained is much more diverse because their values depend continuously on all of the variables, with all the coefficients of the possible multi-dimensional affine maps determining the functions.     

渐开线圆柱齿轮啮合过程中磨损的计算机仿真

利用边界元的基本思想，渐开线直齿圆柱齿轮可以简化到端面进行分析，从而将空间啮合问题转化为平面啮合问题。将边界曲线离散成许多单元和结点，对这些离散点进行啮合和磨损分析，提出了用参数三次样条曲线来模拟磨损后的齿面，实现了对任意啮合点磨损量的计算。编制了一系列的软件，实现了用计算机对齿轮啮合过程中的载荷、应力及磨损进行动态模拟，得出的结果符合通常的磨损规律。     

75Hz消闪烁方案及性能分析

提出了隔行扫描系统７５Ｈｚ消除大面积闪烁的方案，并对此方案的性能进行了较为详细的时域及频域分析．理论分析和初步实验结果表明，此方案对消除电视接收机（尤其是ＨＤＴＶ）的大面积闪烁现象是可行的     

一类三次复平面样条

本文借助于有限元方法的思想对一类三次复平面样条进行了讨论,得到了其存在唯一性的条件,并研究了收敛性、拟正则性和拟共形性等重要性质.     

单片微机在数字压力计中的应用

用二元分段线性——线性插值法对压力传感器的非线性误差及温度误差进行了综合修正.设计了以单片机为核心的微机数据采集与处理系统,该系统在仪器仪表的智能化应用中具有一定的通用性.     

基于摆线滚轮阴模基体的步长伸缩双圆弧插补算法

阴模基体加工精度是影响摆线金刚石滚轮制造精度的关键因素。为了提高摆线滚轮阴模基体在数控机床上的加工精度,首先求解出摆线滚轮阴模基体形面曲线方程,然后基于双圆弧插补法,建立摆线滚轮阴模基体步长伸缩双圆弧插补数学模型,利用数值分析方法求解插补节点数据,控制步长伸缩以调整插补误差。通过计算实例验证了算法的可行性,结果表明:双圆弧插补误差小于0.01 μm,比直线插补误差降低75%;控制步长伸缩,在相同允差下拟合圆弧段数减少55%,提高了加工效率;插补数据拟合的加工仿真曲线光滑平整,刀具路径具备G1连续性。     

图像可逆数据隐藏技术研究综述

可逆数据隐藏技术不仅能从嵌入数据后的载体中完整地提取嵌入的秘密数据,而且能无损地恢复原始载体,这在诸如医学图像、遥感图像等特殊的应用领域非常实用,已成为多媒体安全领域的研究热点。本文以数字图像为载体,首先对信息隐藏技术的分类、应用和特性与可逆数据隐藏技术的基本框架和性能评估进行简要描述。其次,对基于差值扩展、直方图平移、预测误差扩展、像素值排序和插值技术等五种典型的可逆数据隐藏技术分别进行了介绍和讨论,给出了每种典型技术的嵌入和提取过程。最后,对可逆数据隐藏技术未来的研究趋势进行了展望。