Abstract
Soft actuators are versatile and can readily perform various functions and interact safely with humans and the environment owing to their deformability. Shape memory alloys (SMAs) have advantages of high power-to-weight ratio, silent operation, and high response speed, which make them suitable for fabricating soft, compact, and muscle-like soft actuators with various transformation capabilities. However, it is challenging to precisely control SMA-based soft actuators and robots because of the lack of explicit dynamics-based control method. In this study, a linear phase transition model of SMA is derived to express the dynamic model of an SMA planar actuator (SPA) in an explicit form. Then, a model-based feedback controller considering constraints of strain of the SMA, temperature increment of the SPA and load increment, was built. Strain gauges are used to obtain the bending angle of the SPA as the feedback signal for the controller. Various capabilities of the SPA, such as
Photo Gallery: NASA develops tire for Mars missions
David Manley
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A little over a year after the Mars Curiosity Rover landed on Mars, engineers began to notice significant wheel damage in 2013 due to the unexpectedly harsh terrain
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(NASA images, Tire Business Illustration by David Manley)
CLEVELAND While NASA s newest tire is the result of years of research and development, it was a chance meeting between old colleagues that moved it from a unique R&D project to a key piece of an upcoming mission to Mars.
The team at NASA Glenn Research Center in Cleveland engineered a tire the Shape Memory Alloy (SMA) Spring Tire that can handle the heavy load of a lunar rover while traversing rough, rocky Martian terrain and enduring extreme temperatures.
From Tire Business: While NASA's newest tire is the result of years of research and development, it was a chance meeting between old colleagues that moved it from a unique R&D project to a key piece of an upcoming mission to Mars.
CLEVELAND While NASA's newest tire is the result of years of research and development, it was a chance meeting between old colleagues that moved it from a unique R&D project to a key piece of an upcoming mission to Mars.
The team at NASA Glenn Research Center in Cleveland engineered a tire…
Tire Business Illustration by David Manley / NASA images
In 2026, a rover will be launched to Mars to collect samples left across the Martian landscape by Perseverance Rover, which landed on Mars in February. The samples will be dropped at a launch station, sent into space and picked up by an orbiter to return to Earth. Previous damage to the rigid rover wheels led NASA to adopt a Shape Memory Alloy Spring Tire built for the most extreme terrain and temperatures.
CLEVELAND While NASA s newest tire is the result of years of research and development, it was a chance meeting between old colleagues that moved it from a unique R&D project to a key piece of an upcoming mission to Mars.