基于S曲线的数控系统自适应样条插补算法研究

发布时间：2018-06-15 14:04

本文选题：自适应插补算法 + 速度限制曲线　；参考：《浙江理工大学》2015年硕士论文

【摘要】：插补技术是数控系统实现轨迹运动控制的基础，是目前数控技术急需提高和完善的关键环节。插补算法的优劣将直接影响数控系统的性能。其中样条插补技术更是实现高速、高精度数控加工的关键。因此，本文对数控系统中B样条曲线插补算法进行了研究，主要包括以下内容：在文章第二章介绍了数控系统中常用的样条曲线，包括多项式曲线、参数三次样条曲线、B样条曲线以及NURBS曲线，并给出了与曲线相对应的构造过程和表示形式。其中重点介绍了B样条曲线，并通过计算机编程实现了控制点反算、样条绘制等功能，为第四章研究样条插补算法奠定理论基础。在文章第三章研究了数控系统的加减速控制方法，介绍常见的直线加减速方法、指数加减速方法、三角函数加减速方法，重点研究了S型加减速方法，，给出一种基于三种约束条件（位移约束、速度约束和加速度约束）的规划方法，并通过补偿离散化后的精度损失提高整体规划性能。在一般S型加减速模型的基础上，通过推导建立了始末速度不为零的数学模型，该模型将应用于样条插补算法中加减速控制的实现。在文章第四章研究了数控系统中的样条插补算法，介绍了现有样条插补算法，尤其是自适应样条插补算法。在此基础上结合样条理论和S型加减速控制方法，设计了一种基于S型加减速控制方法的自适应样条插补算法，该算法根据给定的加工精度、最大进给速度以及最大加速度等要求，在综合考虑弓高误差和法向加速度限制等情况下，求取样条曲线的速度限制曲线，并依据速度限制曲线和始末速度不为零的加减速模型完成样条插补。最后，通过仿真、实验验证了算法的可行性和实用性，并将该算法应用于自主研制的数控运动平台上，性能表现良好。
[Abstract]:Interpolation technology is the foundation of NC system to realize trajectory motion control, and it is the key link to improve and perfect the NC technology. Interpolation algorithm will directly affect the performance of CNC system. The spline interpolation technology is the key to high-speed and high-precision NC machining. Therefore, this paper studies the interpolation algorithm of B-spline curve in numerical control system, including the following contents: in the second chapter, we introduce the spline curve, including polynomial curve, which is commonly used in CNC system. Parameter cubic spline curve B spline curve and Nurbs curve are given and the corresponding construction process and representation form are given. The B-spline curve is introduced emphatically, and the functions of control point inverse calculation and spline drawing are realized by computer programming, which lays a theoretical foundation for the research of spline interpolation algorithm in Chapter 4. In the third chapter of the paper, the acceleration and deceleration control methods of NC system are studied. The common linear acceleration and deceleration methods, exponential acceleration and deceleration methods, trigonometric function acceleration and deceleration methods are introduced, and the S-type acceleration and deceleration methods are emphatically studied. A programming method based on three constraints (displacement constraint, velocity constraint and acceleration constraint) is presented, and the overall planning performance is improved by compensating the discrete precision loss. Based on the general S-type acceleration and deceleration model, a mathematical model of non-zero velocity is established by derivation. The model will be applied to the realization of acceleration and deceleration control in spline interpolation algorithm. In the fourth chapter, the spline interpolation algorithm in numerical control system is studied, and the existing spline interpolation algorithm, especially the adaptive spline interpolation algorithm, is introduced. On the basis of this, an adaptive spline interpolation algorithm based on S-type acceleration and deceleration control method is designed, which is based on the spline theory and S-type acceleration and deceleration control method. The algorithm is based on the given machining accuracy. When the maximum feed velocity and the maximum acceleration are taken into account, the velocity limit curve of the sampling strip curve is obtained by considering the error of arch height and the limit of normal acceleration. The spline interpolation is completed on the basis of the velocity limiting curve and the acceleration and deceleration model without zero velocity at the beginning and end. Finally, the feasibility and practicability of the algorithm are verified by simulation, and the algorithm is applied to the self-developed CNC motion platform, and the performance of the algorithm is good.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG659

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