Spray gun track planning method for free-form surface spraying robot

The invention discloses a spray gun track planning method for a free-form surface spraying robot. According to the spray gun track planning method disclosed by the invention, the characteristic that a numerical control processing process is very similar to the spaying process is utilized, so that the motion track of a spray gun can be obtained by little calculation on the basis of the tool path. The method comprises the following steps of: firstly, dividing the sprayed surface in three-dimensional modeling software into a plurality of areas with regular shape, generating m equidistant tool paths and deriving the equidistant tool paths into standard APT (Automatic Programming Tools) files by using a five-axis numerical control machining method; extracting tool motion information contained in the APT files, extending the obtained tool points, processing the corner parts into circular arc transition to generate a spray gun path point sequence and then solving a spray gun posture sequence on the path point sequence; and interpolating the spray gun posture sequence to generate a complete motion track of the spray gun. According to the spray gun track planning method disclosed by the invention, accurate control over the track of the spray gun can be realized and the high praying quality is ensured; and the spray gun track planning method is simple in calculation process and calculation amount.