System and method for determining feedrates of machining tools
AssigneeMitsubishi Electric Research Laboratories, Inc.
InventorsHuseyin Erdim, Alan Sullivan
Life of this patent
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Abstract
A method determines a feedrate of a tool machining a workpiece according to a path. The method partitions the path into a set of segments, such that within each segment a function of engagement of the tool and the workpiece is substantially constant. Next, the method determines a feedrate for each segment in the set.
Claims14
A method for determining a feedrate of a tool of a milling system, wherein the tool machining a workpiece according to a path obtained by using a processor in connection with a memory and the milling system, such that the tool moves relative to the workpiece and makes contact with the workpiece over an engagement surface, consisting of an engagement area bounded by a tool entry angle and a tool exit angle which together define an angle of engagement of the tool, where the tool removes material, the method comprising the steps of:
- partitioning the path of the tool into a set of segments, such that within each segment a function of engagement of the tool and the workpiece is substantially constant, such that the partitioning of the path for each segment is based on a variation of the function of engagement of the tool and the workpiece having a swept volume for an area of the workpiece of that segment, the angle of engagement of the tool contacting the area of the workpiece between a tool entry angle and a tool exit angle for that segment, such that the variation of the function of engagement within each partition of the segment is within a predetermined range;
- and
- determining a feedrate of the tool based on the function of engagement for each segment in the set of segments, wherein the determining of the function of engagement includes the engagement angle and one or a combination of geometric properties of the engagement surface, and a parameter defining an abrasive resistance of a material of the workpiece to the machining;
- machining the workpiece based on the determined feedrate of the tool for each segment of the path.
A simulation system for determining a feedrate of a tool during a simulation of a machining of the workpiece by a motion of the tool according to a path, wherein the workpiece is represented by a model of the workpiece including an object distance field defining a surface of the workpiece, the tool is represented by a model of the tool including a tool distance field defining a surface of the tool, and the motion is represented by at least one swept volume including a swept volume distance field defining a surface of the swept volume, the path is represented by a parametric function, comprising a processor for:
- determining a function of engagement of the tool intersecting the workpiece at an instant of the simulation based on distance values between a set of points arranged on the surface of the tool and a surface of an in-process workpiece defined by the object distance field modified by the swept volume distance field at the instant of the simulation to produce a variation of the function of engagement, wherein the tool moves relative to the workpiece and makes contact with the workpiece over an engagement surface, consisting of an engagement area bounded by a tool entry angle and a tool exit angle, which together define an engagement angle, where the tool removes material;
- partitioning the path into a set of segments according to the variation of the function of engagement, such that the partitioning of the path for each segment is based on the variation of the function of engagement of the tool and the workpiece having a swept volume for an area of the workpiece of that segment, and an angle of engagement of the tool contacting the area of the workpiece between a tool entry angle and a tool exit angle for that segment, such that, within each segment, the variation of the function of engagement is within a predetermined range;
- and
- determining a feedrate of the tool based on the function of engagement for each segment in the set of segments, wherein the determining of the function of engagement includes the engagement angle and one or a combination of the engagement surface, and a parameter defining an abrasive resistance of a material of the workpiece to the machining;
- machining the workpiece based on the determined feedrate of the tool for each segment of the path.
A method for determining a feedrate of a tool of a milling system, wherein the tool machining a workpiece according to a path obtained by using a processor in connection with a memory and the milling system, such that the tool moves relative to the workpiece and makes contact with the workpiece over an engagement surface, consisting of an engagement area bounded by entry angle and exit angle which together define an engagement angle, where the tool removes material, the method comprising the steps of:
- partitioning the path of the tool into a set of segments, such that within each segment a function of engagement of the tool and the workpiece is substantially constant, wherein the partitioning includes:
- receiving a set of numerically controlled (NC) segments defined by the path of the tool;
- determining, for each NC segment a variation of the function of engagement;
- and
- partitioning at least one NC segment such that the variation of the function of engagement within each partition of the NC segment is within a predetermined range;
- representing the workpiece by a composite adaptively sampled distance filed (CADF) that includes:
- generating a swept volume for the NC segment of the path of the tool, the NC segment defines the motion of the tool from a previous position to a next position of the tool during a simulation;
- casting rays through the swept volume to represent a motion of the tool in relation to the workpiece;
- determining a volume removed from the workpiece by the swept volume based on intersections of at least some rays with the workpiece;
- and
- determining the variation of the function of engagement based on variations in the removed volume;
- and
- determining a feedrate of the tool based on the function of engagement for each segment in the set of segments, wherein determining the function of engagement includes the engagement angle and one or a combination of geometric properties of the engagement surface, and a parameter defining an abrasive resistance of a material of the workpiece to the machining;
- machining the workpiece based on the determined feedrate of the tool for each segment of the path.
Dependencies are inferred from the claim text.