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1.
从Bezier曲线的数学表达式、二次三次Bezier曲线的矩阵表示、Bezier曲线的性质等出发,组合SPDOS曲线字库内部结构和TURBOC语言程序,来具体说明Bezier曲线在轮廓字中的应用。  相似文献   

2.
提出一种基于已知特征点的单目视觉位姿估计方法。根据摄像机透视投影成像关系,建立四轴飞行器视觉位姿估计模型,设计一种着陆目标图案,提出着陆目标图案特征点提取及标记方法。实验结果表明,该位姿估计算法是有效的。  相似文献   

3.
为提高工业机器人在运行过程中的位姿精度,引入深度学习,开展对其位姿误差自动补偿方法的设计研究。结合深度学习,建立机器人位姿目标识别定位模型,并在RPN网络中完成模型的迭代和学习;为实现对工业机器人位姿误差的自动补偿控制,导入误差自动补偿模糊控制器;最后将位姿误差及补偿结果输出,实现对工业机器人位姿误差的补偿。通过对比实验的方式证明,新的补偿方法可以有效提高工业机器人运行时的位姿精度,进而促进工业机器人运行质量的提升。  相似文献   

4.
该文研究一类类Bezier曲线及其扩展。主要根据一组三角基函数构造由四个控制顶点组成的类Bezier曲线,随后引入基函数中的形状控制参数得到带形状参数的类Bezier曲线,进而构造了带形状参数的类Bezier插值曲线,这是基于通过混合函数混合参数化的控制多边形及类Bezier曲线得到的一类曲线。它具有局部性、端点性质、几何不变性与仿射不变性、对称性、凸包性、变差缩减性等性质。同时它可以表示Bezier曲线所不能表示的圆锥曲线,最重要的性质是其具有插值性,这样就大大增强了其在实际领域中得到应用的可能性。  相似文献   

5.
该文研究一类类Bezier曲线及其扩展。主要根据一组三角基函数构造由四个控制顶点组成的类Bezier曲线,随后引入基函数中的形状控制参数得到带形状参数的类Bezier曲线,进而构造了带形状参数的类Bezier插值曲线,这是基于通过混合函数混合参数化的控制多边形及类Bezier曲线得到的一类曲线。它具有局部性、端点性质、几何不变性与仿射不变性、对称性、凸包性、变差缩减性等性质。同时它可以表示Bezier曲线所不能表示的圆锥曲线,最重要的性质是其具有插值性,这样就大大增强了其在实际领域中得到应用的可能性。  相似文献   

6.
针对五轴加工反向运动学映射机制下,给定刀路轨迹驱动各轴的位移量会随工件切削位姿的不同而存在差异,进而影响进给速度曲线各轴分量的光滑性问题,提出了五轴曲面在线插补实验方法。将工件实际切削位姿综合信息应用于设计前端环节,关注于刀路形貌和切削位姿作用于进给速度曲线的非线性影响,以复杂曲面加工的综合最优效率为目标,开展由切削位姿逆向驱动刀路纹理规划的曲面直接插补方法设计。结果表明,切削位姿反向优化于插补刀路技术作用下的工件表面质量更优于传统五轴曲面加工工件,实现了数控五轴曲面的高速高质量的加工。  相似文献   

7.
传统的建模方法不能精确表示曲面体的弯曲度,针对这些不足,本文采用有理Bezier方法构建曲面模型,给出了椭球体标准型有理二次Bezier控制点和权因子的求解算法;利用非有理Bezier的升阶算法将有理二次Bezier升阶为有理三次Bezier,给出了标准型有理三次Bezier曲线控制点和权因子的求解算法,构建了有理双三次Bezier椭球体曲面模型,通过调整控制点或权因子参数可生成如葫芦、青椒、鸡蛋等光滑的曲面模型.实验表明,该算法具有很好的设计灵活性和交互性,为构建曲面模型提供了新的技术支持.  相似文献   

8.
由于Bezier曲线与曲面的特性,它在计算机的辅助几何设计方面得到广泛的应用。本文在分析Bezier曲线与曲面的基础上,提出了Bezier曲线与曲面极值问题,即最短Bezier曲线与最小Bezier曲面问题,并提出了用模式搜索法与在matlab中用变量极值函数来解决该问题的解法,最后通过实例验证了该解法。  相似文献   

9.
利用B样条曲线的Bezier构造方法,把二次Bezier曲线与三次非均匀B样条曲线的拼接转化为二次Bezier曲线与三次Bezier曲线之间的拼接问题,并分别给出了二次Bezier曲线与三次非均匀B样条曲线的拼接的G0,G1,G2光滑拼接条件.  相似文献   

10.
本文介绍了线切割CAD/CAM系统的自由曲线生成方法.通过比较Bezier曲线、B样条曲线、非均匀有理B样条(NURBS)曲线等主要造型方法,选择了一种适合线切割CAD/CAM系统的简单、易用的几何造型方法,并阐述其算法.  相似文献   

11.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

12.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

13.
一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/  相似文献   

14.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?  相似文献   

15.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

16.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

17.
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.  相似文献   

18.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

19.
现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!  相似文献   

20.
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator's Garden. Translating building data to the Virtual Reality Modeling Language (VRML) is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.  相似文献   

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