基于B样条插值曲线的平面四杆机构轨迹复演优化设计  

OPTIMIZATION SCHEME FOR FOURBAR MECHANISMPATH SYNTHESIS BASED ON BSPLINE

作　　者：黄灿明[1,2] 郭海鹏[1,2] 陈永康[1] 周玉波[1] 

机构地区：[1]香港理工大学 [2]北京航空航天大学

出　　处：《机械工程学报》1998年第3期72-79,共8页Journal of Mechanical Engineering

摘　　要：提出了一种优化法和图谱法相结合的方法来进行平面四杆机构的轨迹复演综合。采用三次非均匀非有理Ｂ样条曲线，把曲线的匹配问题转化为对曲线上的插值点多边形的相似比较，满足了曲线匹配对于平移、旋转、缩放的不变性的要求；模拟人用图谱法进行设计的过程，构造出一种“先粗后精”的搜索法，较好地满足了时间和精度的要求，同时在粗搜索过程中引入随机因素，增加了全局寻优的可靠性。软件计算结果表明该方法是很有效的。An optimization scheme is presented in mechanism pathsynthesis using Bspline curve matching,and fourbar mechanism is used as example to illustrate the approachA space model of the relative linklength types of four bar linkage is used to confine all possible combinations of the four linklengths of the four bar mechanism within a closed region in the three dimensional spaceTherefore all the related couple curver of the four bar mechanism can be derived from the above data modelThe targeted curve for which the mechanism is to be designed can be represented by nonuniform nonrational cubic BsplineThe matching of the targeted curve and the coupler curve can be converted into the matching of polygons generated by either the control points or the interpolation points of Bspline curvesThe maximum corresponding angle deviation of polygons is used as the object function and it can guarantee that the curve matching is independent of movement,rotation,an scale transformAn algorithm for searching the optimum solution in solution space is developed which simulates the trialand error practical design process and can be described as firstroughthenrefinedIn the first rough searching,the whole solution space is browsed through to search for the area for optimum point,and the exact optimum point can be derived by the refined searchingThe searching method presented includes the random effect of point selection in order to enhance the reliability of global optimum

关 键 词：四连杆机构 连杆曲线 曲线匹配 优化 样条插值 

分 类 号：TH112.1[机械工程—机械设计及理论]