Abstract: Automated tape placement (ATP) is an advanced low-cost manufacturing technology for composite materials. Trajectory planning is the key link of ATP, which directly affects the precision and efficiency of the lay-up process, and the quality of the final product. Due to the absence of a gap model, existing trajectory planning methods for ATP usually obtain feasible paths that meet the gap requirements through iterations. This process is time costly, and does not acquire an optimal solution. In view of this, a trajectory optimization method based on the gap prediction model is proposed. Firstly, the gap prediction model is established, which reveals the influence of initial layup conditions, geometric characteristics of the mould surface, geodesic curvature of the placement trajectory and other factors on the gap size. Then, two trajectory optimization strategies are proposed based on the gap model, which transforms the trajectory planning into solving a linear programming problem. Based on the optimization strategies, optimal layup trajectories on several typical mold surfaces are obtained. The experimental results show that in all the examples throughout this paper, the maximum deviation between the prediction gap and the real gap is smaller than 15%, and in most cases, the prediction gap matches the real gap much better than this value. The presented trajectory optimization method solves better layup trajectories that satisfy the gap requirement on the premise of preventing wrinkles, and avoids tedious iterations, which has a guiding significance for the development of high-performance trajectory planning software for ATP.

Key words: ATP, trajectory planning, placement gap, optimization, linear programming