关键词: 椭圆拟合, 椭圆弧拟合, 最小二乘法

Abstract: A fitting method is presented for the double concentric elliptic arcs.In the method，the fitting error is evaluated by the residual error reduced from the ellipse’s geometry definition，and the least-square equations are deduced，which 8 geometric parameters can be solved by iteration method from.Experiments’ result shows that the fitting method will be accurate and stable when the radian is larger，the rate between long axis and short axis is closer to 1.1，and the double elliptic arcs have the lower noise.In addition，the method can be simply extended to solve the fitting problem of several concentric fragmental ellipses.

Key words: ellipse fitting, elliptic arc fitting, least squares methods