Abstract: Based on the Bézier curve with monotone curvature, this paper presented an accurate and efficient spline
interpolation algorithm satisfying G1 constraint. With the given two point-orientation pairs, the construction was to
solve the nonlinear equations using the geometric design criteria of monotone curvature, so as to obtain the Bézier
curve satisfying the G1 interpolation condition. Compared with the interpolation algorithm based on Euler spiral, the
advantages of the proposed method are as follows: simple construction, accurate calculation, and compatibility with
the existing NURBS. Based on the idea of piecewise, this algorithm can deal with the interpolation problems of a
given sequence of points and the direction of head and tail tangents, manifesting stronger adaptability and universality.

Key words: monotone curvature, Bézier curve, G1 interpolation, Euler spiral