Spiral magnetorheological polishing method for mid-spatial-frequency error control

A spiral magnetorheological polishing method for mid-spatial-frequency error control, comprising:

• causing a polishing tool to scan along a raster scanning path line by line through using a magnetorheological polishing technology, and removing workpiece materials by changing an angle between a scanning direction and a workpiece material removal direction at each of processing points in the raster scanning path;
• wherein changing the angle between the scanning direction and the workpiece material removal direction at each of the processing points in the raster scanning path comprises:
• at a start of scanning and upon switching to a next scan line, generating respective random values for the angle such that respective random values corresponding to respective scan lines are different, and for each scan line of the raster scanning path, changing, from a corresponding random value, the angle at each of the processing points of the scan line such that a first one-dimensional profile obtained by superimposing a spiral time-varying tool influence function at respective processing points in a first scan line of the raster scanning path is different from a second one-dimensional profile obtained by superimposing the spiral time-varying tool influence function at respective processing points in each of other scan lines of the raster scanning path.