该文推导了缓和曲线上任意点坐标的方差的加权平均值,来建立描述曲线元不确定性的模型。给出了以缓和曲线法线方向的中误差表示误差带宽的ε_σ模型,以及以最大方向误差表示带宽的ε_m 模型的计算方法。通过实例说明了ε_m 模型是理论上更加严密的缓和曲线误差模型,而ε_σ模型是一种简化的描述模型。

This paper presents two models for describing error of transition curve features based on error of points on the curve. The error nature of such a curve depends on variance covariance matrices of endpoints. The first error model is based on root mean square error in normal direction of the transition curve. The second model is based on error in the maximum direction of the curve. Theoretically, the error model of maximum direction is more rigorous for describing error of transition curve lines. The error model of normal direction is a simplified model of the previous one and is widely used in describing error of straight lines.