Ranger, a bipedal robot built and programmed in Cornell’s Biorobotics and Locomotion lab, led by Andy Ruina, professor of mechanical and aerospace engineering, started walking on Cornell’s Barton Hall track on May 1 just after 2 p.m., and then came to an abrupt stop at on May 2 at 9 p.m., after 30 hours, 49 minutes and 2 seconds of nonstop walking. It covered the 307.75 laps (0.13 miles per lap) at a 1.3 mph amble.
To warm up for the feat, Ranger – donating a participation fee – walked 30 laps in the American Cancer Society’s Relay for Life charity event at Cornell University on April 30.
Ranger’s previous record was 14.3 miles, set last July. Before that, Boston Dynamics’ Bigdog, a four-legged, all-terrain robot, trotted 12.8 miles without refueling. The new Cornell goal was to have a robot walk a full marathon (26.2 miles) without recharge, which Ranger did in just over 20 hours – and then it kept going … and going. In contrast, at the much-publicized world’s first robot marathon in Osaka, Japan in February, robots were repeatedly recharged.
“We were getting pretty tired by the end,” said Violeta Juarez Crow ’12, an electrical engineering major who steered the robot for dozens of laps around the Barton track.
The overall goal of the National Science Foundation-funded research project is to understand walking by reinventing it, said Ruina.
Ranger has six small on-board computers executing about 10,000 lines of computer code. The programs run in a repeating loop every 1/500th of a second. The robot also has dozens of electrical and mechanical sensors. The electronics used 4.7 watts.
“It took a bit of effort to keep the computation, sensing and communication energy use low,” said Jason Cortell, a research support specialist who designed most of the electronics on Ranger. “We hope to use what we have developed for more complex robots.”
The robot’s total weight is 22 pounds, of which 6 pounds are the lithium-ion batteries that power the electronics and the motors. One of these motors extends the outer ankles, another extends the inner ankles and a third swings the legs. A fourth smaller motor twists the inner legs for steering. The motors consume an additional 11.3 watts. At 16 watts total, the specific cost of transport (COT, energy per unit weight per unit distance) was a relatively stingy 0.28 joules per newton-meter. Most robots use much more energy (with a typical COT of 1.5 or more), Ruina said. Ranger still isn’t as efficient as a typical human, who walks with a COT of about 0.2.
Ranger’s present COT of 0.28 is less than its COT last summer of 0.49.
“We’ve improved the control in various ways since then,” said Pranav Bhounsule, the graduate student in charge of the control system. “But I think we can still do better.”
While most legged robots achieve stability by carefully controlling all of the joint angles in their bodies, Ranger achieves its low energy use by, as much as possible, letting the legs swing as they will, Ruina explained. Also, most bipedal robots stand on flat feet. Ranger can’t stand upright at all; instead, it balances by falling and catching itself at each step. The trick is to make the catch at the right time and place.
Ruina said: “Our challenge is to lower the energy use while still maintaining balance. The achievement is to have gone 186,076 steps on 5 cents worth of electricity, and without falling down. … If we try for another record, it will be with automatic steering.”
Blaine Friedlander | Newswise Science News
Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz
Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
19.10.2017 | Materials Sciences
19.10.2017 | Materials Sciences
19.10.2017 | Physics and Astronomy