The integration of origami, art, and technology offers unique opportunities to create products important to society. Origami is particularly well-suited for applications such as automobile airbags because it can be very compact, expand to a large size, and it enables folded patterns to be packed into unique shapes. This flexibility in packing into different shapes is increasingly important for automobile designers. This paper describes the design, testing, and manufacture of two origami patterns for packing airbags into cylindrical spaces, and shows that when folding airbags with origami patterns, the pattern and the packing method both influence how the airbag deploys.
Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags
by Jared T. Bruton, Todd G. Nelson, Trent K. Zimmerman, Janette D. Fernelius, Spencer P. Magleby, Larry L. Howell
From: The Royal Society
Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the ‘flasher’ and the ‘inverted-cone fold’, for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver’s side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes.
Introduction and background
Soft Origami and use of soft-sheet materials
1. Introduction and background
1.1 Origami and engineering design
1.2. Soft Origami and use of soft-sheet materials
2. Cylindrical packing and deployment
2.1. Pattern selection and modelling
2.2. Packing methods
2.3. Deployment rotation
3. Application: automotive airbags
3.1. Packing methods applied
3.2. Deployment performance
3.3. Packing method modification based on deployment performance
3.4. Deployment performance for new packing methods
An undeployed flasher pattern with cylindrical envelope shown around it. Specified height H and diameter D are variables of interest.
4. Discussion and conclusion
In this paper, fold patterns and packing methods have been introduced and evaluated to efficiently pack soft-sheet materials into cylindrical packed shapes with configurable folded (packed) height and diameter, deployed (unfolded) shape and deployed size. Deployment performance and the impact of packing method on deployment was also explored. Twofold patterns (the flasher and the inverted-cone fold) and a total of two packing methods for the first pattern and four for the second pattern were presented as viable solutions. Application to automotive airbags was explored and results showed promise, although the flasher was shown to be less-than-ideal for driver’s side airbags and would probably be more valuable in other Soft Origami applications.
Both fold patterns have adjustable stowed height and diameter, deployed shape and deployed size while folding into approximately cylindrical shapes. We were able to influence the behaviour of the airbag using this approach, and preliminary testing showed that we were able to specify packed behaviour, unfolding behaviour via pressure difference deployment and final deployed shape. Both patterns showed favourable improvements in packing an airbag into a cylindrical shape with sufficient room underneath the packed material for an inflator.
Multiple possible methods were created and explored to fold the inverted-cone fold and flasher fold patterns using a rigid frame that is later removed. After frame removal, the folds are ready to be deployed by way of a pressure differential. The patterns, shown through an application to automotive airbag folding, accomplished the desired goals of the research. The packing methods demonstrated here have been shown to work when folded by hand (with a combination of a mechanism and human intervention), but have not yet been automated, which could be a topic of further work.
Another accomplishment of this research was the modification of packing method based on deployment performance. Although the same pattern (the inverted-cone fold) was used, different packing methods were shown to influence deployment performance, which is probably true of many Soft Origami patterns and applications. That is, unlike traditional origami, where fold lines constrain behaviour, Soft Origami allows for a more quantitative approach wherein the same pattern can be packed using many different methods (with varying fidelity to the original pattern) depending on the application constraints. However, different packing methods and levels of discretization result in packed patterns that match the original desired pattern with varying degrees of fidelity.
In conclusion, multiple patterns and packing methods were presented that are well-suited for packing a soft-sheet material into a cylindrical volume prior to deployment via internal pressure. Another unique development in this work is the use of an origami-pattern-inspired folding frame to impose the pattern on the soft-sheet materials, and then removing the folding frame and maintaining the folded shape for use in deployment via pressure difference (e.g. inflation). This is advantageous for a mechanism or structure that would present a safety hazard to humans if it had a rigid understructure when deploying. In an application to automotive airbags, we also demonstrated the principle of modifying the packing method (within the same origami fold pattern) based on deployment performance and requirements.
From: The Royal Society