Abstract: This paper derives the direct coordination formula of imcomplete spiral curve and presents a kind of straightforward pattern which is very convenient for solving non-symmetric alignment design unit of imcomplete spiral.

Key words: plane alignment, incomplete spiral, non-symmetric alignment design unit

摘要： 本文给出了计算不完整回旋线坐标的直接公式,提出了一种求解不完整回旋线的非对称线形单元的简明图式,并为复杂线形的分析和计算提供了一条简单易行的思路.

关键词: 平面线形, 不完整回旋线, 非对称线形设计单元