基于B样条空间等距线的机器人轨迹优化算法  

Robot Trajectory Optimization Algorithm Based on Spatial Offset B-Spline

作　　者：胡绳荪[1,2] 庹宇鲲 申俊琦[1,2] 陈昌亮[3] 谷文 李坚 

机构地区：[1]天津大学天津市现代连接技术重点实验室,天津300072 [2]天津大学材料科学与工程学院,天津300072 [3]天津职业技术师范大学天津市高速切削与精密加工重点实验室,天津300222 [4]中国第一重型机械集团核电石化事业部,大连116113

出　　处：《天津大学学报（自然科学与工程技术版）》2015年第8期723-727,共5页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(50975195);天津市应用基础及前沿技术研究计划资助项目(10JCYBJC06500)

摘　　要：针对J形坡口焊接机器人轨迹示教中理论轨迹与实际轨迹偏差较大的问题,利用实际轨迹的空间等距线逼近下一道焊接轨迹,并设计了相贯线轨迹等距线的B样条逼近算法.算法主要包括:基于等曲线弧长准则对原B样条曲线取样;利用向心算法计算取样点的等距点;计算插值于该等距点的3次B样条曲线;在给定的全局误差限内去除多余控制顶点.试验结果表明:等距点的向心算法可以有效解决相贯线曲线局部修改后主法向量发散的问题;全局插值方法可以保留原曲线修改特征;全局误差限下去除多余控制顶点可以减少B样条曲线控制顶点数目.For the problem of the large deviation between the theoretical trajectory and the real trajectory of the J-groove joint welding robot during trajectory teaching, a solution is proposed using the offset spline of the real trajec-tory to approximate the next welding trajectory. An approximation algorithm for offset B-spline of intersecting splines is designed, which includes the following steps： sampling the original B-spline with the uniform curve arc length crite-rion; calculating the offset points of the sample points with the centripetal algorithm; fitting a cubic B-spline with global interpolation; removing most control points under the global error bound. The experimental results are as fol-lows： the centripetal algorithm could solve the problem of the divergence of the principal normal vectors after local modification on the intersecting curve; the algorithm of global interpolating could retain the modification features of the original trajectory; the algorithm of removing control points under global error bound could remove most control points effectively and reduce the number of control points of B-spline.

关 键 词：J形坡口 球管相贯线 B样条 等距线 逼近 

分 类 号：TG409[金属学及工艺—焊接]