Much of the advanced sensing technology developed by Intellisense Systems has focused on characteristics that are invisible to the human eye. Unseen elements inside the weather, wilderness, or large bodies of water are now detectable thanks to technology from Intellisense. We are now making strides in identifying the invisible qualities of physical objects as well. With innovations like our non-destructive evaluation (NDE) tools that can detect filaments and debris smaller than a strand of hair, Intellisense can find defects and ensure safety for any number of structural applications. One of those applications has been used by the United States Army for many decades, and it was instrumental in helping the Allied powers win World War II.
Paratroopers have presented an incredible strategic advantage for many militaries over the 20th and 21st century. Aerial delivery provides the military with a key capability in the battlefield, as it allows for sustainment of operational forces from strategic distances and conducting military missions under adverse conditions. The ability to clandestinely drop soldiers and supplies from the air enables armed forces around the world to seize key objectives and areas. For these operations to be successful, however, service members rely on the integrity of their parachutes to ensure a safe landing.
The polymer cords on a typical parachute must be lightweight and strong enough to withstand the forces of safely bringing a human to terra firma. But after multiple jumps, the cords can deform and wear in ways that are undetectable to the human eye. The U.S. Military wished to ensure the integrity of these parachutes as part of an effort to evaluate their service life and guarantee the safety of service members. They wanted to quantify strain data for the development of new parachutes so that they could maintain these critical paratrooping operations.
To fulfill these needs, Intellisense Systems devised a structural sensor that integrated core conducting bi-component polymer fibers into parachute cords. They identified the best construction parameters for a conductive fiber strain sensor that did not impact the functionality of the parachute cords. These fibers could be incorporated into nearly any hollow-core suspension line and provide invaluable strain data while remaining lightweight and robust.
Intellisense began the development process by leveraging previous developments in NDE tools of a helicopter sling load (HSL) component. This technology used a small percentage of conductive fiber yarns added to the core and outer braids of the sling rope to monitor and predict the number of unbroken fibers and, thus, the residual break strength in the rope. This technology offered an electronic, non-destructive means of inspecting ropes, ensuring that slings maintained their integrity and saving costs by preventing premature disposition of slings. And because the conductive fibers are added to the standard fiber count, rope strength was not diminished.
Using this previous internal development, the engineers at Intellisense identified configurations that optimized measurement sensitivity, repeatability, and ease of fabrication. Repeated laboratory experiments revealed how the sensors would respond to wind and gravitational forces once integrated into a suspension line. They successfully fabricated conductive nylon sensing fiber with a 40% improvement in resistivity over the fibers used in the previous HSL development. They also demonstrated that there is very strong correlation between the tensile force on the HSL sling and the sensor output (electrical resistance). Environmental tests revealed temperature sensitivities of the structural sensors, which the Intellisense team accounted for in the sensor reading output. At the conclusion of testing, Intellisense successfully fabricated parachute suspension lines integrated with sensor yarns and conducted two air drop tests. Dynamic forces in individual suspension lines were measured using a Ram Air parachute, demonstrating this technology’s viability in an operational environment.
Intellisense demonstrated the feasibility of this polymer sensor system for use with both personnel- and cargo-transporting parachute systems in dynamic situations. They also identified value for this system in civilian applications like search-and-rescue operations.
Knowledge of dynamic forces on individual ropes and parachute suspension lines will help improve the reliability of these systems and provide safe and accurate air delivery methods. With this latest structural sensor development from Intellisense, essential aid, equipment, and personnel can be safely and accurate air-dropped into remote or denied terrain. And with innovations in environmental-monitoring systems, users of Intellisense products can go forth with greater confidence and awareness of the world.