Abstract: Automated tape placement (ATP) is one kind of additive manufacturing technology, and suitable for manufacturing composite components with large size and small curvature, such as airfoil and panel. This technology has the advantage of low cost and high efficiency. Trajectory planning is the key link of ATP, which directly affects the precision and efficiency of the lay-up process, and the quality of final product. Existing trajectory planning methods for ATP generally show difficulties in adjusting lay-up gaps and conveniently suppressing the appearance of wrinkles at the same time. For this reason, a multi-level trajectory planning method based on quasi-geodesic is presented. The proposed approach takes advantage of the deformability of prepreg to prevent overlaps and gaps which are greater than 2.5 mm between adjacent tapes. Firstly, the evolution law of lay-up gaps on non-developable surfaces is deduced. At the same time, an optimization strategy for initial lay-up gaps on several typical surfaces is introduced. Then, a mathematical model for quasi-geodesic is established on the basis of differential geometry. Next, the magnitude and sign of the geodesic curvature on the quasi-geodesic is specified based on the forming mechanism of wrinkles and the evolution law of lay-up gaps. Lastly, the proposed methodology is validated on a hyperboloid surface and a freeform surface.

Key words: ATP, trajectory planning, geodesic, composite material, prepreg