等误差圆弧逼近法，是一种节点计算在理论上精确的、误差带位置和允许误差大小都可事前控制而无需重复计算的方法。一、计算方法对于曲率半径单调变化（如变小）的一段非圆曲线ｙ＝ｆ（ｘ），如图１所示，过其上一点Ｐ１（ｘ１，ｙ１）作半径为Ｒ的曲率圆Ｃ，则当ｘ＞ｘ１时， Equal error arc approximation method is a kind of node calculation theoretically accurate error band position and allow the size of the error can be controlled in advance without the need for double counting. First, the calculation method for a monotonically changing curvature radius (such as smaller) of a non-circular curve y = f (x), shown in Figure 1, past its previous point P1 (x1, y1) , Then when x> x1,