基于B样条转速函数的凸轮机构运动优化

Motion optimization of cam mechanisms based on B-spline speed function

改变凸轮转速函数,而不改变凸轮轮廓,可以调整出合适的凸轮机构输出特性。B样条曲线作为通用的数学描述形式,具有灵活的调整性。文中首先推导出变速凸轮机构的传递函数,提出以非均匀B样条曲线作为凸轮转速函数,讨论了节点矢量的确定方法。构建了凸轮机构的运动优化模型,并确定了约束条件。最后,通过两个优化实例证明了该方法的有效性。

The motion characteristics of the cam mechanisms can be adjusted flexibly by varying the input speed of cam,and not changing the cam profile. The B-spline curve, as the uniform mathematics expression, can be differently shaped depending on its control points. The transfer function of variable-speed cam mechanisms is inferred firstly. Then speed function is described as a non-uniform B-spline curve, and the method to confirm the knot vector is discussed. Then the motion optimization of variable-speed cam mechanisms and its constraints are developed. Finally, two examples are given to illustrate the proposed method and also to show its feasibility and validity.