Error Estimation of Machined Surfaces in Multi-Axis Machining with Machine Tool Errors Including Tool Self-Intersecting Motion Based on High-Accuracy Tool Swept Volumes

Abstract

A novel method is proposed for estimating the machining errors on machined surfaces caused by errors of multi-axis machine tools, such as geometric errors, based on a new generating method of tool swept volumes. In the proposed tool swept volume generation method, the boundary surfaces of the tool swept volumes are derived as triangular mesh models satisfying the required approximation accuracy based on the tangency condition. Using the proposed method, tool swept volumes can be derived for various tool paths including the tool self-intersecting motion. A tool path evaluation method based on the error vectors with respect to the start position of a specific tool path is also proposed. In the proposed evaluation method, error vectors on machined surfaces are derived by comparing the points on the nominal tool swept volumes (excluding the machine tool errors) with the triangles on the error tool swept volumes (including the machine tool errors).