Rosie, the housekeeper from The Jetsons, has been the archetypal representative of helper robots since she wheeled onto televisions screens in the early 1960s. While Rosie vacuumed and washed dishes without a hint of incoordination, it turns out her real-world counterpart is far more likely to tip over and become a hindrance instead of a helper.
The contemporary version of the Rosie robot is actually considered highly unstable, but researchers from the King Fahd University of Petroleum & Minerals in Saudi Arabia have proposed a control design of the wheeled inverted pendulum assistant robot called I-PENTAR.
They published their design in IEEE/CAA Journal of Automatica Sinica (JAS), a joint publication of the IEEE and the Chinese Association of Automation
"One of the key challenges in using robots is... uncertainty," wrote Magdi Mahmoud, a Distinguished Professor at the King Fahd University of Petroleum & Minerals in Saudi Arabia, and an author on the paper. "The challenge is how to increase the performance of such robots with the existence of this uncertainty. The development of more robust and fast controller algorithms can tackle uncertainty.
Mahmoud and his team examined four stabilization approaches for their control design, aimed at maintaining stability in the face of uncertainty. Uncertainty cannot be entirely removed, so the robot must account for it. Each approach involved analyzing the input-output relationship and how the robot maintain stability even as the input changed.
The robot, I-PENTAR, has a waist joint, two arms--with elbows--and a wheeled inverted pendulum mobile platform. I-PENTAR must be able to assess the ground upon which it moves, including the angle and grip, and it must be able to remain upright with control.
The researchers found that a dynamic feedback structure best modeled the results they wanted in simulations, so they experimentally tested the control algorithm. The goal was to achieve stability even with the presence of uncertainty.
"The upper balancing enables the robot to keep its original position without losing its balance," wrote Mahmoud. "The robot was initially tilted 8 [degrees] but the angular velocity of the tilt angle was zero... After almost 3 [seconds], the position of the center of the base returned to its original position."
It's a far cry from the laundry-doing, dish-washing Rosie, but I-PENTAR may be the first roll toward the robotic help promised more than 50 years ago.
Fulltext of the paper is available: http://ieeexplore.
IEEE/CAA Journal of Automatica Sinica (JAS) is a joint publication of the Institute of Electrical and Electronics Engineers, Inc (IEEE) and the Chinese Association of Automation. The objective of JAS is high quality and rapid publication of articles, with a strong focus on new trends, original theoretical and experimental research and developments, emerging technologies, and industrial standards in automation. The coverage of JAS includes but is not limited to: Automatic control,Artificial intelligence and intelligent control, Systems theory and engineering, Pattern recognition and intelligent systems, Automation engineering and applications, Information processing and information systems, Network based automation, Robotics, Computer-aided technologies for automation systems, Sensing and measurement, Navigation, guidance, and control. JAS is indexed by IEEE, ESCI, EI, Inspec, Scopus, SCImago, CSCD, CNKI. We are pleased to announce the new 2016 CiteScore (released by Elsevier) is 2.16, ranking 26% among 211 publications in Control and System Engineering category.
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