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直线段与B样条曲线的一种新的双向裁剪迭代求交算法 被引量:1
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作者 夏德麟 严俊 《计算机应用与软件》 CSCD 1994年第6期1-7,共7页
本文根据B样条曲线的性质与线段的半平面方程的特性,研讨了B样条曲线与直线段的相交性问题,提出了有关这类线段相交性的判别准则及其求交新算法。该方法能避免大量的无效求交计算,并大大提高了求交效率。
关键词 双向裁剪迭代 算法 直线段 b样条曲线
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基于前瞻S曲线的B样条连续小线段插补算法 被引量:1
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作者 孙征 梁秀满 《华北理工大学学报(自然科学版)》 CAS 2018年第1期113-118,共6页
针对激光雕刻机雕刻连续小线段时出现的拐点过渡不平滑和加工效率低等问题,提出了一种基于非均匀B样条曲线插补算法和具有速度前瞻功能的S型曲线加减速算法相结合的连续小线段高速加工方法。首先利用非均匀B样条算法将小线段进行拟合,... 针对激光雕刻机雕刻连续小线段时出现的拐点过渡不平滑和加工效率低等问题,提出了一种基于非均匀B样条曲线插补算法和具有速度前瞻功能的S型曲线加减速算法相结合的连续小线段高速加工方法。首先利用非均匀B样条算法将小线段进行拟合,然后结合离散的S型曲线加减速算法对雕刻速度进行规划,最后将速度前瞻模型应用到小线段转折点处的速度规划中,从而减小冲击力并提高激光头在拐点处的加工速度。结果表明,该加工方法能够实现小线段在拐点处的平稳衔接,提高运动速度和插补准确性。 展开更多
关键词 激光雕刻 小线段 高速加工 非均匀b样条曲线 S型加减速算法 速度前瞻
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适应数控加工的空间曲面的建立
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作者 李丙才 梁秀娟 +1 位作者 嵇海旭 田相克 《兰州理工大学学报》 CAS 北大核心 2004年第5期45-48,共4页
论述了适应数控加工B样条曲面建立的方法,指出了B样条曲面具有一、二阶连续的特性,可以用多个曲面片的拼接而组成任意形状的自由曲面,从而解决了数控加工中空间曲面建模的难题,为建立空间自由曲面提供了理论依据.
关键词 数控加工 b样条曲线和曲面 曲面片 基底函数
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适应数控加工的三维曲面建模
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作者 田相克 马保聪 《机械制造与自动化》 2007年第3期46-48,共3页
论述了适应数控加工B样条曲面建立的方法,指出了B样条曲面具有一、二阶连续的特性,可以用多个曲面片的拼接而组成任意形状的自由曲面,从而解决了数控加工中空间曲面建模的难题,为建立空间自由曲面提供了理论依据。
关键词 数控加工 b样条曲线和曲面 曲面片 基底函数
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Path planning for agricultural robots in wild livestock farm environments
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作者 Haixia Qi Jinzhuo Jiang Chaohai Wang 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第4期207-216,共10页
Path planning for field agricultural robots must satisfy several criteria:establishing feeding routes,maintaining gentle slopes,approaching multiple livestock observation points,ensuring timely environmental monitorin... Path planning for field agricultural robots must satisfy several criteria:establishing feeding routes,maintaining gentle slopes,approaching multiple livestock observation points,ensuring timely environmental monitoring,and achieving high efficiency.The complex terrain of outdoor farming areas poses a challenge.Traditional A*algorithms,which generate only the shortest path,fail to meet these requirements and often produce paths that lack smoothness.Therefore,identifying the most suitable path,rather than merely the shortest one,is essential.This study introduced a path-planning algorithm tailored to field-based livestock farming environments,building upon the traditional A*algorithm.It constructed a digital elevation model,integrated an artificial potential field for evaluating multiple target points,calculated terrain slope,optimized the search neighborhood based on robot traversability,and employed Bézier curve segmentation for path optimization.This method segmented the path into multiple curves by evaluating the slopes of the lines connecting adjacent nodes,ensuring a smoother and more efficient route.The experimental results demonstrate its superiority to traditional A^(*),ensuring paths near multiple target points,significantly reducing the search space,and resulting in over 69.4%faster search speeds.Bézier curve segmentation delivers smoother paths conforming to robot trajectories. 展开更多
关键词 field-based livestock farming agricultural robots path planning A*algorithm artificial potential field bézier curve segmentation
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Geometric meanings of the parameters on rational conic segments 被引量:4
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作者 HU Qianqian WANG Guojin 《Science China Mathematics》 SCIE 2005年第9期1209-1222,共14页
Using algebraic and geometric methods,functional relationships between a point on a conic segment and its corresponding parameter are derived when the conic segment is presented by a rational quadratic or cubic Bé... Using algebraic and geometric methods,functional relationships between a point on a conic segment and its corresponding parameter are derived when the conic segment is presented by a rational quadratic or cubic Bézier curve.That is,the inverse mappings of the mappings represented by the expressions of rational conic segments are given.These formulae relate some triangular areas or some angles,determined by the selected point on the curve and the control points of the curve,as well as by the weights of the rational Bézier curve.Also,the relationship can be expressed by the corresponding parametric angles of the selected point and two endpoints on the conic segment,as well as by the weights of the rational Bézier curve.These results are greatly useful for optimal parametrization,reparametrization,etc.,of rational Bézier curves and surfaces. 展开更多
关键词 rational bézier curve CONIC segment ellipse hyperbola parabola parameterization.
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