Massachusetts Institute of Technology (MIT) researchers have developed an algorithm for gauging the rotation of objects in zero gravity using only visual information.
The researchers tested the algorithm using two small satellites deployed to the International Space Station through MIT's SPHERES project, which aims to develop hundreds of volleyball-sized robotic satellites that could assist human crews on future space missions. During testing, the algorithm was very accurate except when measuring the distribution of an object's mass in real time. However, its estimate could still be adequate for many purposes, according to the researchers.
The algorithm uses a probabilistic approach to simultaneously calculate all of its estimates. "If you're just building a map, it'll optimize things based on just what you see, and put no constraints on how you move," says former MIT graduate student Brent Tweddle, who is now at the U.S. National Aeronautics and Space Administration's Jet Propulsion Laboratory.
The researchers found the natural log of the ratio between moments of inertia around the different rotational axes of the object could be modeled by a Gaussian distribution. "Gaussian distributions have a lot of probability in the middle and very little probability out at the tails, and they go from positive infinity to negative infinity," Tweddle says.
From MIT News
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