Automated fiber placement with course trajectory compensation

• US 9,545,759 B2
• Filed: 01/30/2015
• Issued: 01/17/2017
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: CGTech Co.
• Original Assignee: CGTech (Sandvik AB)
• Inventors: Yarker, Thomas, Hasenjaeger, William H.
• Primary Examiner(s): Randazzo, Thomas
• Application Number:
  US14/610,569
• Publication Number:
  US 20160221271A1
• Time in Patent Office: 718 Days
• US Class Current: 1/1
• CPC Class Codes: B29C 70/02 comprising combinations of reinforcements, e.g. non-specified reinforcements, fibrous reinforcing inserts and fillers, e.g. particulate fillers, incorporated in matrix material, forming one or more layers and with or without non-reinforced or non-filled layers combinations of fibrous reinforcement only B29C70/04; combinations of fillers only B29C70/58; combinations with non reinforcing inserts, e.g. foam blocks, B29C70/68
• CPC Class Codes: B29C 70/38 Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns application heads for tyres B29D30/28
• CPC Class Codes: B29C 70/382 Automated fiber placement [AFP]
• CPC Class Codes: B29L 2031/30 Vehicles, e.g. ships or aircraft, or body parts thereof vanes or blades B29L2031/08, air bags B29L2022/027
• CPC Class Codes: G06F 2113/26 Composites
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30

Abstract

Various automated fiber placement systems and methods are disclosed. The system can determine steerable paths for the application of a composite material over highly contoured surfaces. The system can determine when a course trajectory would violate a steering limitation (e.g., a maximum bendability of the composite material) and can adjust the trajectory to avoid such violations. The adjustment can create gaps between adjacent courses, which can have a generally flared peripheral shape. The system can fill such gaps with subsequent courses of the composite material. Thus, the system can automatically apply composite material to highly contoured surfaces while also avoiding violation of the steering limitations.

Claims

1. A system for determining course trajectories for the application of tows of composite material to a curved surface using an automated fiber placement machine, the system comprising:

a non-transitory storage that stores data related to the shape and dimensions of the surface and that stores an indication of a steering limitation; and

a computing system comprising one or more computing devices, the computing system in communication with the non-transitory storage and programmed to;

access, from the non-transitory storage, the data related to the shape and dimensions of the surface and the indication of the steering limitation;

produce, based on the data, a plurality of course trajectories for the application of tows over the surface, the trajectories being generally parallel to each other;

determine, for each course trajectory, whether any of the tows would violate the steering limitation;

adjust each course trajectory having a tow that violates the steering limitation, the adjustment comprising determining a course trajectory that;

avoids the violation of the steering limitation; and

intentionally diverges from an adjacent course trajectory, thereby creating a gap between the adjusted course trajectory and the adjacent course trajectory, the gap having a flared shape that comprises a lateral width that is greater than the lateral width of a single one of the tows; and

produce at least one additional course trajectory located in the gap.

2. The system of claim 1, wherein, for a particular course trajectory having at least one tow that violates the steering limitation, the computing system is programmed to adjust the course trajectory by:

determining a tow in the particular course that is located laterally farthest from an adjacent and previous course;

determining, for the tow located laterally farthest from the adjacent and previous course, the longest segment of the tow that complies with the steering limitation;

determining a curve that approximates the longest segment of the tow; and

plotting an adjusted course trajectory having the curve as the centerline.

3. The system of claim 1, wherein the at least one course trajectory located in the gap intersects with another course, wherein the system is configured to cause the automated fiber placement machine to use the adjusted and additional course trajectories.

4. The system of claim 1, further comprising the automated fiber placement machine, wherein the system is configured to cause the automated fiber placement machine to use the adjusted and additional course trajectories.

5. The system of claim 1, wherein:

the computing system is further programmed to produce, based on the data, a plurality of layers, at least one of the layers comprising the plurality of course trajectories; and

wherein the adjusted course trajectory and the adjacent course trajectory are in the same layer.

6. The system of claim 1, wherein the steering limitation specifies a maximum amount an individual tow is permitted to bend on the surface.

7. The system of claim 6, wherein the steering limitation corresponds approximately to a maximum amount an individual tow can bend without incurring a flawing event.

8. The system of claim 6, wherein the computing system is further programmed to:

receive a comfortable steering limitation; and

determine, for each course trajectory, whether a tow would violate the comfortable steering limitation.

9. The system of claim 8, wherein the computing system is further programmed to:

receive a length limitation;

determine, for a tow that violates the comfortable steering limitation, the length of the portion of the tow that violates the comfortable steering limitation; and

adjust the course trajectory for those course trajectories having a tow in which the length of the portion of the tow that violates the comfortable steering limitation is greater than the length limitation.

10. Non-transitory computer storage having stored thereon executable program code that directs a computer system to implement a process that comprises:

receiving dimensional data for a contoured surface on which a plurality of courses of composite material are to be applied, each course comprising a plurality of tows;

receiving a steering limitation related to the ability of an individual tow to traverse a curve;

determining a trajectory of a first course on the surface;

determining a trajectory of a second course on the surface, the second course adjacent to and generally parallel to the first course;

analyzing the trajectory of the second course to determine whether any of the tows in the second course violate the steering limitation; and

determining an alternate trajectory for the second course in response to determining that a tow in the second course violates the steering limitation, the alternate trajectory complying with the steering limitation, the alternate trajectory comprising;

a first portion of the second course that is generally parallel to the first course; and

a second portion of the second course that diverges from the first course in such a way as to form a gap between the second portion of the second course and the first course, the gap having a flared shape that comprises a lateral width that is greater than the lateral width of a single one of the tows.

11. The storage of claim 10, wherein the process further comprises filling a portion of the gap with a third course.

12. The storage of claim 11, wherein the third course is generally parallel with the second portion of the alternate trajectory of the second course.

13. The storage of claim 10, wherein the steering limitation comprises approximately the minimum radius of curvature around which a tow can bend on the surface.

14. The storage of claim 13, wherein the process further comprises:

receiving a comfortable steering limitation;

receiving a length limitation;

determining that a tow in the second course violates the comfortable steering limitation;

determining the length of the portion of the tow that violates the comfortable steering limitation;

determining that the length of the portion is greater than the length limitation; and

determining an alternate trajectory for the second course.

15. The storage of claim 14, wherein the comfortable steering limitation comprises the minimum radius of curvature around which a tow can bend plus a factor of safety.

16. The storage of claim 15, wherein the factor of safety is at least 25% of the minimum radius of curvature around which a tow can bend.

17. A method of controlling an automated fiber placement machine configured to apply a plurality of layers of courses of composite material to a form, each course comprising a plurality of tows, the method comprising:

receiving information indicative of the shape and extent of the form;

receiving a limitation on the amount an individual tow can be bent when applied to the form without incurring a flawing event;

producing a plurality of generally parallel path course trajectories over the form, the plurality of generally parallel path course trajectories being in the same layer;

identifying those course trajectories in which at least one tow violates the limitation;

replacing, for those course trajectories in which at least one tow violates the limitation, the parallel path course trajectory with a flared path course trajectory in which all of the tows of that course are made to diverge from the generally parallel path course trajectory, thereby creating a gap between the flared path course trajectory and an adjacent generally parallel path course trajectory; and

producing at least one additional course trajectory to fill the gap, the additional course trajectory being in the same layer as the flared path course trajectory.

18. The method of claim 17, wherein the additional course trajectory intersects the previous course, and wherein the method further comprises cutting the ends of tows in the additional course trajectory at the intersection.

19. The method of claim 17, further comprising producing an instruction set of courses.

20. The method of claim 19, further comprising instructing the automated fiber placement machine to apply the courses to the form based on the instruction set.