  In order to improve the quality and stability of synchrotron light, Hefei
Light Source has a major upgrade. Higher accuracy is necessary for installation
and alignment of the storage ring magnets. It is not necessarily essential that
the magnets are positioned exactly. In fact, the aim is to adjust neighboring
magnets with a high accuracy to one another; in other words, these neighboring
magnets are positioned on a smoothing curve. The paper presents an attempt to
develop a reliable smoothing method based on curve fitting of least squares and
iteration according to the structure characteristics of HLSII. The method
significantly reduces the adjusting amount and range of the storage ring
magnets. It improves productivity by a factor of one times.
