The invention provides an automatic
trajectory planning method and
system for multi-layer and multi-channel wire arc additives of a
metal structure. The automatic
trajectory planning method comprises the following steps: Step 1, conducting layered
slicing treatment on a model of a printed workpiece; Step 2, after obtaining a layered relation matrix, calculating a
contour line according to triangles recorded in the matrix by means of a topological relation; Step 3, calculating filling line segments; Step 4, sorting all the intersection points obtained in the Step 3 according to the size of the
X coordinate; Step 5, connecting the filling line segments; and Step 6, carrying out layered direction-changing scanning. Multi-layer and multi-channel 3D printing of a
metal structural part is carried out according to the composite printing path of outer wall + short straight line filling + layered direction-changing filling, chemical components of a formed workpiece are uniform, the purity is high, and the structure is almost free of
anisotropy. Multi-layer and multi-channel 3D printing of the
metal structural part is carried out according to the composite printing path of outer wall + short straight line filling + layered direction-changing filling, the grain size of the formed workpiece is small and uniform, the mechanical performance is high, and the level of the formed workpiece can exceed that of a
casting with the same component.