A Trajectory planning technique for grinding and polishing aerospace turbine blades’ thermal barrier coatings based on PCL point cloud processing

The core components of an airplane are its aerospace engines, which are intricate in a wide range of applications and specialties. Their high technological barriers make them a crucial barometer of the power of an industrialized nation. The most common component in an engine among these pieces are the aviation blades. Thermal barrier coatings are very beneficial to aviation engine blades because they increase their resistance to high temperatures and corrosion, extending their lifespan in an environment where high temperatures, stress, and corrosion are common. However, the surface roughness of the coating during its application directly impacts engine performance. To reduce the surface roughness, it is necessary to grind and polish the coated surface. Traditional methods involve manual grinding and polishing or CNC machining. The former heavily relies on the skill level of workers, making it challenging to ensure precision, especially for small-sized blades with complex surface curvature. The latter, due to high costs and limited adaptability to various blade types, particularly for small blades, often fails to meet processing requirements. To address these challenges, this paper proposes an automatic grinding and polishing technique based on industrial robots. The method creates robot pathways that adapt to the complex surfaces of the blades by preprocessing scanned point cloud pictures of the blades, segmenting and discretizing the point cloud, and fitting B-spline curves. This approach ensures precision in grinding and polishing while preserving the coating thickness. It also enables quick changes to robot trajectories for various kinds of blades. Based on experimental results, the suggested method can meet the accuracy requirements for industrial blade grinding and polishing procedures by reducing roughness to less than Ra0.7μm while preserving the thickness of the blade coating.