Approximation of Archimedes spiral with polynomial s-power basis

To make Archimedes spiral segments fit the form of curve in the current CAD system, the approximation algorithm was proposed. The method is based on s-power series, the two-point analogue of Taylor expansions. First, the define of s-power series was reviewed; and then the formula to calculate the s-power coefficients of Archimedes spiral segments was given; finally, the algorithm was described step by step. The results of example show that the approximation method by use of s-Power Basis are correct and effective, and then suitable for the use of the CAD system.