This paper presents a methodology and algorithms of optimizing and smoothing the tool orientation control for 5-axis sculptured surface machining. A searching method in the machining configuration space (C-space) is proposed to find the optimal tool orientation by considering the local gouging, rear gouging and global tool collision in machining. Based on the machined surface error analysis, a boundary search method is developed first to find a set of feasible tool orientations in the C-space to eliminate gouging and collision. By using the minimum cusp height as the objective function, we first determine the locally optimal tool orientation in the C-space to minimize the machined surface error. Considering the adjacent part geometry and the alternative feasible tool orientations in the C-space, tool orientations are then globally optimized and smoothed to minimize the dramatic change of tool orientation during machining. The developed method can be used to automate the planning and programming of tool path generation for high performance 5-axis sculptured surface machining. Computer implementation and examples are also provided in the paper.

Optimizing tool orientations for 5-axis machining by configuration-space search method

This paper presents a methodology and algorithms of admissible tool orientation control for gouging avoidance in 5-axis machining. A method is proposed to find the admissible tool orientation by considering both local and global surface shapes. A filleted endmill is used in this study for 5-axis machining. Based on the evaluation of local surface shape, a geometry analysis method is developed to first find a feasible tool orientation for gouging avoidance along two orthogonal cutting places. Adjacent geometry is then taken into consideration for detecting possible rear gouging. A localization algorithm is developed for filleted endmills to identify potential rear gouging area. Both the circular approximation, and the detailed gouging checking methods are proposed for rear gouging correction. The techniques presented in this paper can be used to eliminate errors of tool paths as they are generated. Unlike the traditional graphical verification and user-interactive correction of tool path generation, the proposed methodology can be used to automate the planning and programming of cutter path generation for 5-axis machining.

Admissible tool orientation control of gouging avoidance for 5-axis complex surface machining

Presented in this paper is a new approach to 5-axis NC tool path generation for sculptured surface machining. Techniques of feasible machining strip evaluation are used for non-isoparametric 5-axis tool path generation. A searching algorithm is proposed to find the parameter increments of adjacent cutter locations along orthogonal path intervals for optimal non-isoparametric path generation. Compared to the use of the smallest path interval by the traditional constant parametric path planning, the proposed methodology can generate efficient tool paths for sculptured surface machining by reducing the redundant overlapping between adjacent tool paths. The proposed methodology includes three steps: (1) evaluating feasible machining strip, (2) solving parameter increments (Δu, Δv) along orthogonal path intervals, and (3) searching for adjacent non-isoparametric cutter locations. The techniques presented in this paper can be used to improve 5-axis machined surface quality and to automate the non-isoparametric cutter path generation for CAD/CAM systems.

Non-isoparametric tool path planning by machining strip evaluation for 5-axis sculptured surface machining

Recently, a large amount of new research related to numerical control (NC) tool path generation has appeared in the literature Unfortunately, finding information on a particular topic can be difficult Not only does path generation span several disciplines, but the material tends to vary both in content and focus In this paper, the literature is partitioned into categories and papers related to path generation classified according to the topics they cover This should be useful to those looking for references on specific topics as well as those seeking an introduction to the literature as a whole

https://www.cgl.uwaterloo.ca/smann/Papers/survey2.pdf

A classified bibliography of literature on NC milling path generation

This paper presents a method to improve the machining efficiency for 5-axis surface machining with a flat-end cutter. In the proposed method, the cutter paths are scheduled so that the scallop height formed by two adjacent machining paths is maintained constant. Along each machining path, the inclination angle of the flat-end cutter is tuned adaptively so that the cutter-path interval can be chosen as large as possible. With the adaptively cutter-inclined iso-scallop method, the machining path length required to finish the part surface is minimized.

Efficient cutter-path planning for five-axis surface machining with a flat-end cutter

In this paper, application of convex hull is proposed to solve the problem of global tool interference avoidance in 5-axis sculptured surface machining. Two different methods for interference checking have been developed. Quick Feasibility Checking is used to find a conservative feasible tool orientation by using the control mesh of a sculptured surface. Detailed Feasibility Checking uses exact surface to detect tool interference. A correction method for removing tool interference has also been developed. In this paper both the algorithms and the implementation are presented.

Tien-Chien Chang

Papers

2-Phase approach to global tool interference avoidance in 5-axis machining