![]() ![]() Simulations show that the proposed curve-fitting method can generate smooth toolpath and constrain fitting error. The feasibility and effectiveness of the proposed method have been validated by simulations and experiments on the S-shape test piece. Then the feedrate is deformed for the tool orientation to guarantee smooth rotary motion as well as to share the same motion time with the tool-tip position segment by segment. The tool-tip position trajectory is firstly planned to address axial kinematic constraints in the feedrate scheduling process. The fitting error is controlled by locally refining the curve segments that exceed the fitting tolerance. Two C2-continuous and error-bounded B-spline curves are produced to fit tool-tip position and tool orientation, respectively. Aiming at these problems, this paper proposes a double B-spline curve-fitting and synchronization-integrated feedrate scheduling method. For path synchronization, the parameter synchronization method cannot ensure smooth rotary motion. ![]() For path smoothing, with the global curve-fitting method it is difficult to control fitting error and the local corner-smoothing method has large curvature extreme. The discontinuities of a five-axis linear-segment toolpath result in fluctuation in the feedrate, acceleration and jerk commands that lead to machine tool vibration and poor surface finish. Improve the quality of the product with lesser machining time. Of the techniques applied to utilize 5 axis machine tools to Special attention is given to cutting tools and tool holding systems Impact on the efficient utilization of the 5 axis machine tools. Recent developments in CAD/CAM also have made greater Thisįurther also leads to substantial saving of the manufacturing cost. To achieve high quality with shorter manufacturing time. However, to perform these operations, often specialįixtures, special tooling, tools with longer out sticks, andĮxpensive electrodes are needed. Sharp corners are demonstrated successfully using 5 axis machine ![]() Machining operations involving undercut areas, deep cavities, The capability to perform intricate machining operations. Overcome their limitations of working in order to machine all the The effectiveness of the proposed method to smoothen the five-axis tool paths have been demonstrated with simulations and experiments. At last, the tool axis orientation and tool tip positions are synchronized to avoid discontinuous displacements along the tool axis, and the maximum feedrate allowed on the bottom corner transition spline would be further limited when the bottom or top corner transition spline is revised. Then, the top tool axis orientation path segments are smoothed with additional feedrate synchronization constraint. In the paper, the bottom tool path segments are first smoothed by Bezier spline with an optimized feedrate while respecting corner error tolerance and tangential kinematic limits. To improve the machining accuracy, this paper takes the maximum feedrate allowed on the tool tip position spline as one of the constraints to keep the path deviation of tool axis orientation within the tolerance when the tool axis orientation is smoothed. Compared with the previous work, this paper improves the machining efficiency by optimizing the maximum feedrate along the transition splines while respecting the corner transition error tolerance, chord error tolerance, and tangential kinematic limits (i.e., the feedrate command, tangential acceleration, and jerk limits) at the connection points or “corners”. This paper aims to improve the machining efficiency and accuracy of previously presented G³ continuous tool path smoothing method for 5-axis CNC machining (Sun and Altintas in CIRP J Manuf Sci Tec 32:529–549, ). Discontinuities at the junctions of linear segments reduce the machining efficiency, leave marks on the finish surfaces, and cause higher tracking errors, hence leading to larger contouring errors. Parts with free-form surfaces are machined by connecting short linear tool path segments on five-axis computer numerical control (CNC) machining centers.
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