Replacement path machining method and apparatus

An aircraft component machined using a method comprising:

• specifying a tool path for a cutting tool, the tool path being a unidirectional path along which the cutting tool is to be moved during machining of the aircraft component, wherein the tool path comprises a plurality of pre-identified tool path segments (26, 28, 30);
• defining, for each tool path segment (26, 28, 30), an entry point, wherein the entry point of a tool path segment (26, 28, 30) is a point on that tool path segment (26, 28, 30), through which the tool enters and does not exit the respective tool path segment (26, 28, 30);
• defining, for each tool path segment (26, 28, 30), an entry path (32, 34, 36), wherein the entry path (32, 34, 36) of a tool path segment (26, 28, 30) is a path for the cutting tool from a point that is remote from the aircraft component to the entry point of that tool path segment (26, 28, 30);
• specifying a sequence comprising a plurality of machining points along the tool path, each machining point being a point along the tool path at which a respective feature (20, 22, 24) is to be machined into the aircraft component, wherein each tool path segment (26, 28, 30) includes one or more machining points;
• moving a first cutting tool (6) along the tool path from a first point on the tool path to a second point on the tool path;
• as the first cutting tool (6) is moved from the first point to the second point, machining, by the first cutting tool (6), aircraft component, for each of the machining points the first cutting tool (6) is moved to, controlling the first cutting tool (6) to machine the corresponding feature (20, 22, 24) into the aircraft component;
• for each machining point, assigning, to that machining point, either a first label or a second label, wherein the first label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has not been machined, and the second label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has been machined;
• after the first cutting tool (6) has been moved to the second point, moving the first cutting tool (6) to a point remote from the aircraft component, identifying the first machining point in the sequence to which the first label has been assigned;
• moving a second cutting tool (18) along the entry path (32, 34, 36) of the tool path segment (26, 28, 30) containing the identified machining point, in which the second point is located, from a point that is remote from the aircraft component to the entry point of the tool path segment (26, 28, 30) containing the identified machining point, in which the second point is located;
• and
• moving the second cutting tool (18) along the tool path from the entry point of the tool path segment (26, 28, 30) in which the second point is located to the second point.

Apparatus for machining a workpiece (2), the apparatus comprising:

• a first cutting tool (6);
• a second cutting tool (18);
• one or more processors (10) configured to:
• store a tool path for a cutting tool (6), the tool path being a unidirectional path along which a cutting tool is to be moved during machining of the workpiece (2), wherein the tool path comprises a plurality of pre-identified tool path segments (26, 28, 30), each tool path segment (26, 28, 30) comprising an entry point, wherein the entry point of a tool path segment (26, 28, 30) is a point on that tool path segment (26, 28, 30), through which the tool enters and does not exit the respective tool path segment (26, 28, 30);
• and
• store, for each tool path segment (26, 28, 30), an entry path (32, 34, 36), wherein the entry path (32, 34, 36) of a tool path segment (26, 28, 30) is a path for the cutting tool from a point that is remote from the workpiece (2) to the entry point of that tool path segment (26, 28, 30);
• specify a sequence comprising a plurality of machining points along the tool path, each machining point being a point along the tool path at which a respective feature (20, 22, 24) is to be machined into the workpiece (2), wherein each tool path segment (26, 28, 30) includes one or more machining points;
• and
• a controller (8) configured to:
• move a first cutting tool (6) along the tool path from a first point on the tool path to a second point on the tool path;
• as the first cutting tool (6) is moved from the first point to the second point, machine, using the first cutting tool (6), the workpiece (2), for each of the machining points the first cutting tool (6) is moved to, control the first cutting tool (6) to machine the corresponding feature (20, 22, 24) into the workpiece (2);
• for each machining point, assign, to that machining point, either a first label or a second label, wherein the first label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has not been machined, and the second label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has been machined;
• after the first cutting tool (6) has been moved to the second point, move the first cutting tool (6) to a point remote from the workpiece (2), identify the first machining point in the sequence to which the first label has been assigned;
• move a second cutting tool (18) along the entry path (32, 34, 36) of the tool path segment (26, 28, 30) containing the identified machining point in which the second point is located from a point that is remote from the workpiece (2) to the entry point of the tool path segment (26, 28, 30) containing the identified machining point in which the second point is located;
• and
• move the second cutting tool (18) along the tool path from the entry point of the tool path segment (26, 28, 30) in which the second point is located to the second point.

A non-transient machine readable storage medium storing a program or at least one of the plurality of programs arranged such that when executed by a computer system or one or more processors it/they cause the computer system or the one or more processors to operate in accordance with a method of machining a workpiece (2) comprising:

• specifying a tool path for a cutting tool, the tool path being a unidirectional path along which the cutting tool is to be moved during machining of the workpiece (2), wherein the tool path comprises a plurality of pre-identified tool path segments (26, 28, 30);
• defining, for each tool path segment (26, 28, 30), an entry point, wherein the entry point of a tool path segment (26, 28, 30) is a point on that tool path segment (26, 28, 30), through which the tool enters and does not exit the respective tool path segment (26, 28, 30);
• defining, for each tool path segment (26, 28, 30), an entry path (32, 34, 36), wherein the entry path (32, 34, 36) of a tool path segment (26, 28, 30) is a path for the cutting tool from a point that is remote from the workpiece (2) to the entry point of that tool path segment (26, 28, 30);
• specifying a sequence comprising a plurality of machining points along the tool path, each machining point being a point along the tool path at which a respective feature (20, 22, 24) is to be machined into the workpiece (2), wherein each tool path segment (26, 28, 30) includes one or more machining points;
• moving a first cutting tool (6) along the tool path from a first point on the tool path to a second point on the tool path;
• as the first cutting tool (6) is moved from the first point to the second point, machining, by the first cutting tool (6), the workpiece (2), for each of the machining points the first cutting tool (6) is moved to, controlling the first cutting tool (6) to machine the corresponding feature (20, 22, 24) into the workpiece (2);
• for each machining point, assigning, to that machining point, either a first label or a second label, wherein the first label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has not been machined, and the second label is assigned to a machining point if the feature (20, 22, 24) corresponding to that machining point has been machined;
• after the first cutting tool (6) has been moved to the second point, moving the first cutting tool (6) to a point remote from the workpiece (2), identifying the first machining point in the sequence to which the first label has been assigned;
• moving a second cutting tool (18) along the entry path (32, 34, 36) of the tool path segment (26, 28, 30) containing the identified machining point, in which the second point is located, from a point that is remote from the workpiece (2) to the entry point of the tool path segment (26, 28, 30) containing the identified machining point, in which the second point is located;
• and
• moving the second cutting tool (18) along the tool path from the entry point of the tool path segment (26, 28, 30) in which the second point is located to the second point.