A Tool-path Planning Method Used in Computer Controlled Optical Surfacing Based on Improved Prim Algorithm

In view of the disadvantages of existing planning methods used in CCOS techniques, such as low efficiency and workpieces contain obvious mid-frequency error after polishing, a new tool-path planning method based on improved Prim algorithm was proposed, of which the core idea was consist by following steps: surface data reading, mesh generation, distribution of resident points determining and polishing path generating. After that, comparison of raster path and the path based on improved Prim algorithm was carried out by simulated experiments from aspects of path length and polishing texture. The results indicated that the path based on improved Prim algorithm could shorten path length as well as increase polishing efficiency, moreover, both the texture and mid-frequency errors can be improved by using the path presented. It was concluded that the presented planning method could improve polishing efficiency and machining quality. Then, comparison between raster path and the path based on improved Prim algorithm was carried out by simulated experiments, from two sides of path length and polishing texture. The results indicated that the path based on improved Prim algorithm could shorten path length as well as increase polishing efficiency, moreover, both the texture and mid-frequency errors would be improved by using the presented path. Finally, the validity of presented planning method was proved in machining experiments.

Coverage Based Tool-Path Planning For Automated Polishing Using Contact Mechanics Theory

Presented in this thesis is a method for tool-path planning for automated polishing. This work is an intergral part of the research program on automated polishing/deburring being carried out at Ryerson University. Whereas tool-path planning for machining is treated as a geometry problem, it ks shown here that tool-path planning for polishing should be treated as a contact mechanics problem because of the contact action between the polishing tool and the part surface. To develop this algorithm, contact mechanics is applied for contact area modeling and analysis, Once the contact area is determined, for multiple contact points along the given polishing path, a map of the contact area is generated and utilized to show the coverage area during polishing. This map is then used to plan a polishing path that ensures complete coverage for polishing, Simulation has been carried out to show the effetiveness of this new polishing path algorithm.

Coverage Based Tool-Path Planning For Automated Polishing Using Contact Mechanics Theory

Presented in this thesis is a method for tool-path planning for automated polishing. This work is an intergral part of the research program on automated polishing/deburring being carried out at Ryerson University. Whereas tool-path planning for machining is treated as a geometry problem, it ks shown here that tool-path planning for polishing should be treated as a contact mechanics problem because of the contact action between the polishing tool and the part surface. To develop this algorithm, contact mechanics is applied for contact area modeling and analysis, Once the contact area is determined, for multiple contact points along the given polishing path, a map of the contact area is generated and utilized to show the coverage area during polishing. This map is then used to plan a polishing path that ensures complete coverage for polishing, Simulation has been carried out to show the effetiveness of this new polishing path algorithm.

Pseudo-random Path Generation Algorithms and Strategies for the Surface Quality Improvement of Optical Aspherical Components

This study proposes two path generation algorithms to diminish the superposition of the convolution effect on the polishing path in computer-controlled optical surfacing. According to the polishing of aluminum-alloy based hyperboloid optical components, different proportions of polishing agents were blended. Then, the surface roughness of the optical components were determined through a validation experiment of the algorithms. Furthermore, the relationship between surface roughness and the polishing agent concentration, and the compensation strategies for surface roughness were analyzed. The results show that the two algorithms effectively compensated for surface waviness. The findings support the strategies for improving the surface quality of optical components with aspherical surfaces.

Polishing path generation for physical uniform coverage of the aspheric surface based on the Archimedes spiral in bonnet polishing

As a new polishing method, bonnet polishing is suitable for polishing the curved surface due to its advantages in flexibility and adaptability of the polishing tool. In the polishing process, the contact state between the bonnet and the curved surface always changes. The traditional polishing tool path with equal interval will inevitably lead to over-polished areas and unpolished areas. In this article, a new tool path for bonnet polishing, which is called the revised Archimedes spiral polishing path, is proposed to ensure the physical uniform coverage of the curved surface in bonnet polishing. The path generation method is based on the modified tool–workpiece contact model and the pointwise searching algorithm. To prove the effectiveness of the revised path, two aspheric workpieces were polished along the traditional Archimedes spiral polishing path and the revised path, respectively. The roughnesses of the two workpieces are 10.94 and 10 nm, and the profile tolerances are 0.4097 and 0.2037 μm, respectively. The experimental results show that the revised path achieves lower roughness and surface tolerance than the traditional Archimedes path, which indicates that the revised path can achieve uniform physical coverage on the surface.