A new computational design methodology provides a practical tool for designing telescoping structures. Telescoping structures have a wide range of applications and are particularly useful when a device must be compact and easily deployable.
Despite their broad usefulness, this is the first study to investigate the kinds of shapes that can be telescoped. Straight structures, like the eponymous telescope, are useful, but finding curved or twisted shapes would greatly expand the kinds of devices that retract into smaller spaces. The research team at Carnegie Mellon University that conducted the study point to the potential utility of a telescoping robotic arm or a heart stent that can expand once inserted.
"Among deployable mechanisms, telescopes are very interesting. Once you expand them, they are very flexible and you can make a lot of different shapes, all with the same telescope," notes Keenan Crane, coauthor and Assistant Professor of Computer Science and Robotics at Carnegie Mellon. "We wanted to know what are all the possible shapes you can make from a telescoping structure."
The team, which included Ph.D. student Christopher Yu and Assistant Professor Stelian Coros, set three requirements for their modeling software: the shells must be manufactured of rigid material; the telescope must expand and contract without bumping into itself; and there should be no empty space between the telescoping segments when retracted. Their research led to an insight—that complicated mechanical descriptions of a telescope can be reduced to simple geometric curves.
Two prototype objects, a telescoping robotic arm and a structure that unfolds to several times its original volume, serve as proof of concept. The researchers will present a paper describing their research, “Computational Design of Telescoping Structures,” at ACM’s SIGGRAPH conference in Los Angeles July 30-August 3.