Object production

• US 10,025,293 B2
• Filed: 04/10/2015
• Issued: 07/17/2018
• Est. Priority Date: 04/24/2014
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Bickerstaff, John, Wilson, David Mark
• Primary Examiner(s): Pan, Yuhui R
• Application Number:
  US15/303,860
• Publication Number:
  US 20170036780A1
• Time in Patent Office: 1,194 Days
• CPC Class Codes: B64F 5/10 Manufacturing or assembling aircraft, e.g. jigs therefor
• CPC Class Codes: G05B 19/4097 characterised by using design data to control NC machines, e.g. CAD/CAM G05B19/4093 takes precedence
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/35134 3-D cad-cam

Abstract

Disclosed is a method of producing an object, the method comprising: providing a workpiece comprising a plurality of attachment features for attaching the workpiece to a machining fixture; determining a datum, the datum being dependent upon the relative positions of the attachment features; measuring the surface of the workpiece with respect to the datum; providing the machining fixture; attaching, using the attachment features, the workpiece to the machining fixture; providing a digital model specifying the object including the attachment features; and, thereafter, using the measurements of the workpiece surface and the digital model, controlling machining apparatus with respect to the datum to machine the workpiece so as to produce the object as specified by the digital model.

Claims

1. A method for producing a system, the method comprising:

providing a workpiece comprising a plurality of attachment features for attaching the workpiece to a machining fixture, said machining fixture comprising a plurality of fixture receiving elements for receiving the attachment features of the workpiece, the relative positions of the fixture receiving elements being dependent upon the relative positions of the attachment features;

determining a datum, the datum being dependent upon relative positions of the attachment features, said determining the datum including measuring the relative positions of the fixture receiving elements on the machining fixture and using the measurements of the relative positions of the fixture receiving elements, calculating the datum;

measuring a surface of the workpiece with respect to the datum;

providing the machining fixture;

attaching, using the attachment features, the workpiece to the machining fixture;

providing a digital model specifying a component of the system, the digital model including the attachment features;

using the measurements of the workpiece surface and the digital model, controlling the machining apparatus with respect to the datum to machine the workpiece attached to the machining fixture so as to produce the component as specified by the digital model;

removing the component from the machining fixture;

providing an assembly tool;

attaching, using the attachment features, the component to the assembly tool; and

performing an assembly operation on the component, thereby producing the system.

2. The method according to claim 1, wherein the system is at least part of an airframe of an aircraft.

3. The method according to claim 2, wherein the system is at least part of an airframe aft fuselage.

4. The method according to claim 1, wherein the component is an airframe component selected from the group of airframe components consisting of a frame and a longeron.

5. The method according to claim 1, wherein:

the system is configured for attachment to a further system; and

the step of providing the assembly tool comprises;

determining a position and orientation relative to the further system that the component would have if the system was attached to the further system;

using the determined position and orientation of the component relative to the further system, determining one or more positions and orientations relative to the further system at which the component is to be supported;

providing a jig frame;

attaching, to the jig frame, a reference structure;

providing a plurality of pickup devices each having a pickup receiving element for receiving a component of the system; and

securing each pickup device to the jig frame such that each pickup receiving element is at a predetermined position and orientation relative to the reference structure that will position the component at the determined position and orientation relative to the further system at which the component is to be supported.

6. The method according to claim 1, wherein the step of determining the datum comprises:

measuring the relative positions of the attachment features on the workpiece; and

using the measurements of the relative positions of the attachment features, calculating the datum.

7. The method according to claim 1, wherein the step of providing the machining fixture comprises:

providing an initial machining fixture;

providing a further digital model specifying the machining fixture; and

using the further digital model and the datum, controlling machining apparatus with respect to the datum to machine the initial machining fixture so as to produce the machining fixture as specified by the further digital model.

8. The method according to claim 1, wherein

the machining fixture comprises one or more reference surfaces, each reference surface being associated with a component feature;

and

machining the workpiece comprises, for each reference surface;

locating at least part of the machining apparatus against that reference surface; and

controlling the machining apparatus to move away from that reference surface with respect to the datum to machine the workpiece so as to form the component feature associated with that reference surface.

9. The method according to claim 8, wherein

the step of providing the machining fixture comprises:

providing an initial machining fixture;

providing a further digital model specifying the machining fixture; and

using the further digital model and the datum, controlling machining apparatus with respect to the datum to machine the initial machining fixture so as to produce the machining fixture as specified by the further digital model; and

the step of providing the further digital model comprises;

using the digital model of the component, identifying one or more component features;

for each identified component feature, determining a position and orientation of a reference surface thereof relative to the datum; and

using the determined a positions and orientations of the one or more reference surfaces, determining the further digital model.

13. A system produced using the method according to claim 1.

14. The system according to claim 13, wherein the system is at least part of an airframe aft fuselage.

10. An apparatus for producing a system that incorporates a component formed from a workpiece comprising a plurality of attachment features, the apparatus comprising:

a machining fixture configured to receive the workpiece at the attachment features, said machining fixture comprising a plurality of fixture receiving elements for receiving the attachment features of the workpiece, the relative positions of the fixture receiving elements being dependent upon the relative positions of the attachment features;

one or more processors configured to determine a datum, the datum being dependent upon relative positions of the attachment features, said determining of the datum including measuring the relative positions of the fixture receiving elements on the machining fixture and using the measurements of the relative positions of the fixture receiving elements, calculating the datum;

measurement apparatus suitable for measuring a surface of the workpiece with respect to the datum;

machining apparatus being configured to, using the measurements of the workpiece surface and a digital model specifying the component of the system including the attachment features, be controlled so as to machine the workpiece attached to the machining fixture so as to produce the component as specified by the digital model;

an assembly tool configured to receive the component at the attachment features; and

an assembly apparatus suitable for performing an assembly operation on the component on the assembly tool, thereby producing the system.

11. The apparatus according to claim 10, wherein the system is at least part of an airframe of an aircraft.

12. The apparatus according to claim 11, wherein the system is at least part of an airframe aft fuselage.