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US 9,164,503 B2Granted
Method of optimizing toolpaths using medial axis transformation
AssigneeThe Boeing Company
InventorsJared Lee Bolin, Philip L. Freeman
Life of this patent
Estimating the term…
Abstract
Rough machining of a workpiece is performed by a numerically controlled machine tool using an adaptive toolpath technique. Material removal rate and machine efficiency are increased by forming a pre-roughing slot in the workpiece along medial axes, and machining the remainder of the workpiece using a toolpath that begins inside the pre-roughing slot and spirals outwardly in smooth curves.
Claims22
A method of machining a workpiece using an automatically controlled cutting tool, comprising:
- selecting a cut boundary defining a shape of an area of the workpiece to be machined;
- determining a medial axis transformation of the shape, including generating a set of medial axis curves describing the shape;
- selecting at least one of the medial axis curves for use in generating a pre-roughing toolpath;
- generating the pre-roughing toolpath based on the at least one of the medial axis curves;
- automatically machining a pre-roughing slot in the workpiece using a cutting tool and the pre-roughing toolpath guiding the cutting tool via cutting a first circular recess comprising a first desired axial depth into the workpiece, centered at a first end of the medial axis, cutting a full length of the pre-roughing slot, and then cutting a second circular recess comprising a second axial depth into the workpiece, centered at a second end of the medial axis;
- generating a roughing toolpath using a constant radial depth of cut of a cutting tool with the workpiece, based on a geometry of the pre-roughing slot, such that the roughing toolpath comprises a starting position, for the cutting tool, inside the pre-roughing slot;
- automatically machining a remainder of the area of the workpiece using the cutting tool and the roughing toolpath to guide the cutting tool;
- and
- automatically machining the remainder of the area of the workpiece using the roughing toolpath to guide the cutting tool in curves spiraling outward from the pre-roughing slot such that the cutting tool precludes a need for at least one of:
- a reversal of a direction of travel of the cutting tool, and a substantial deceleration and acceleration of the cutting tool.
7 more elements
A method of rough-machining a workpiece using a numerically controlled machine tool, comprising:
- selecting a cut boundary defining a shape of an area of the workpiece to be machined;
- determining a medial axis transformation of the shape, including generating a set of medial axis curves describing the shape;
- selecting at least one of the medial axis curves for use in generating a pre-roughing toolpath;
- generating the pre-roughing toolpath based on the at least one of the medial axis curves;
- automatically machining a pre-roughing slot in the workpiece using a cutting tool and the pre-roughing toolpath guiding the cutting tool via cutting a first circular recess comprising a first desired axial depth into the workpiece, centered at a first end of the medial axis, cutting a full length of the pre-roughing slot, and then cutting a second circular recess comprising a second axial depth into the workpiece, centered at a second end of the medial axis;
- generating a roughing toolpath using a constant radial depth of cut of a cutting tool with the workpiece, based on a geometry of the pre-roughing slot, such that the roughing toolpath comprises a starting position, for the cutting tool, inside the pre-roughing slot;
- automatically machining a remainder of the area of the workpiece using the cutting tool and the roughing toolpath to guide the cutting tool;
- and
- automatically machining the remainder of the area of the workpiece using the roughing toolpath to guide the cutting tool in curves spiraling outward from the pre-roughing slot such that the cutting tool precludes a need for at least one of:
- a reversal of a direction of travel of the cutting tool, and a substantial deceleration and acceleration of the cutting tool.
7 more elements
A method of rough-machining a workpiece having at least one narrow region, comprising:
- inputting a cut boundary to a computer that defines a shape of an area of the workpiece to be machined;
- using the computer to perform a medial axis transformation of the shape, including generating a set of medial axis curves describing the shape;
- selecting at least one of the medial axis curves for use in generating a pre-roughing toolpath;
- using the computer to generate the pre-roughing toolpath based on the at least one of the medial axis curves;
- automatically machining a pre-roughing slot in the workpiece using a cutting tool and the pre-roughing toolpath guiding the cutting tool via cutting a first circular recess comprising a first desired axial depth into the workpiece, centered at a first end of the medial axis, cutting a full length of the pre-roughing slot, and then cutting a second circular recess comprising a second axial depth into the workpiece, centered at a second end of the medial axis;
- using the computer to generate a roughing toolpath using a constant radial depth of cut of a cutting tool with the workpiece, based on a geometry of the pre-roughing slot, such that the roughing toolpath comprises a starting position, for the cutting tool, inside the pre-roughing slot;
- automatically machining a remainder of the area of the workpiece using the cutting tool and the roughing toolpath to guide the cutting tool;
- and
- automatically machining the remainder of the area of the workpiece using the roughing toolpath to guide the cutting tool in curves spiraling outward from the pre-roughing slot such that the cutting tool precludes a need for at least one of:
- a reversal of a direction of travel of the cutting tool, and a substantial deceleration and acceleration of the cutting tool.
7 more elements
Dependencies are inferred from the claim text.