Navigation Links
Lessons from cockroaches could inform robotics
Date:2/22/2013

ANN ARBORRunning cockroaches start to recover from being shoved sideways before their dawdling nervous system kicks in to tell their legs what to do, researchers have found. These new insights on how biological systems stabilize could one day help engineers design steadier robots and improve doctors' understanding of human gait abnormalities.

In experiments, the roaches were able to maintain their footing mechanicallyusing their momentum and the spring-like architecture of their legs, rather than neurologically, relying on impulses sent from their central nervous system to their muscles.

"The response time we observed is more than three times longer than you'd expect," said Shai Revzen, an assistant professor of electrical engineering and computer science, as well as ecology and evolutionary biology, at the University of Michigan. Revzen is the lead author of a paper on the findings published online in Biological Cybernetics. It will appear in a forthcoming print edition.

"What we see is that the animals' nervous system is working at a substantial delay," he said. "It could potentially act a lot sooner, within about a thirtieth of a second, but instead, it kicks in after about a step and a half or two stepsabout a tenth of a second. For some reason, the nervous system is waiting and seeing how it shapes out."

To arrive at their findings, the researchers sent 15 cockroaches (one-by-one, in 41 trials) running across a small bridge onto a placemat-sized cart on wheels. The cart was attached to an elastic cord that was pulled tight like a loaded slingshot and held in place with a strong magnet on the other side. Once a roach was about a body length onto the cart, the researchers released the magnet, sending the cart hurling sideways. The force was equivalent to a sumo wrestler hitting a jogger with a flying tackle, said Revzen, adding that cockroaches are much more stable than humans.

To gather detailed information about the roaches' gait, the researchers utilized a technique Revzen developed several years ago called kinematic phase analysis. It involves using a high-speed camera to constantly measure the position of each of the insects' six feet as well as the ends of its body. A computer program then merges the continuous data from all these points into an accurate estimate of where the roach is in its gait cycle at all times. The approach gives scientists a more detailed picture than just measuring the timing of footfallsa common metric used today to study gait.

In kinematic phase analysis, the signals are converted into a wave graph that illustrates the insect's movement pattern. The pattern only changes when the nervous system kicks in. How do the researchers know this? In a separate but similar experiment, they implanted electrodes into the legs of seven cockroaches to measure nerve signals.

The nervous-system delay the researchers observed is substantially longer than scientists expected, Revzen said. And it runs contrary to assumptions in the robotics community, where computers stand in for brains and the machines' movements are often guided by continuous feedback to that computer from sensors on the robots' feet.

Revzen said the new findings might imply that the biological brain, at least in cockroaches, adjusts the gait only at whole-step intervals rather than at any point in a step. Periodic, rather than continuous, feedback systems might lead to more stable (not to mention energy-efficient) walking robotswhether they travel on two feet or six.

Robot makers often look to nature for inspiration. As animals move through the world, they have to respond to unexpected disturbances like rocky, uneven ground or damaged limbs. Revzen and his team believe that patterns in how they move as they adjust could give away how their machinery and neurology work together.

"The fundamental question is, 'What can you do with a mechanical suspension versus one that requires electronic feedback?" Revzen said. "The animals obviously have much better mechanical designs than anything we know how to build. But if we could learn how they do it, we might be able to reproduce it."

More than 70 percent of Earth's land surface isn't navigable by wheeled or tracked vehicles, so legged robots could potentially bridge the gap for ground-based operations like search and rescue and defense.

For human gait analysis, Revzen and colleagues said their noninvasive, high-resolution kinematic phase approach could be valuable in the biomedical community.

"Falls are a primary cause for deterioration in the elderly," Revzen said. "Anything we can do to understand gait pathology and stabilization of gait is very valuable."

These experiments were conducted at the University of California, Berkeley, before Revzen came to U-M. The work was funded by the National Science Foundation.


'/>"/>

Contact: Nicole Casal Moore
ncmoore@umich.edu
734-647-7087
University of Michigan
Source:Eurekalert

Related biology news :

1. Woolly mammoth extinction has lessons for modern climate change
2. Climate and drought lessons from ancient Egypt
3. Lessons from Bangladesh
4. Biodiversity conservation depends on scale: Lessons from the sience-policy dialogue
5. Biodiversity conservation depends on scale: Lessons from the science-policy dialogue
6. Bergen-Belsen lessons underline vital role that nurses can play in patient feeding
7. Mass extinction study provides lessons for modern world
8. Research, response for future oil spills: Lessons learned from Deepwater Horizon
9. Early music lessons boost brain development
10. Heart-powered pacemaker could one day eliminate battery-replacement surgery
11. New test could help track down and prosecute terrorists
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/16/2016)... -- Research and Markets has announced the addition of ... 2021" report to their offering. ... The biometric vehicle access system market, in ... 14.06% from 2016 to 2021. The market is estimated to be ... Million by 2021. The growth of the biometric vehicle access system ...
(Date:12/15/2016)... , Dec 15, 2016 ... Research and Markets has announced the addition ... offering. The report forecasts the global military biometrics market ... The report has been prepared based on an in-depth market ... and its growth prospects over the coming years. The report also includes ...
(Date:12/12/2016)... -- Researchers at Trinity College, Dublin, are opening up ... material with Silly Putty. The mixture (known as "G-putty") ... sense pulse, blood pressure, respiration, and even the ... The research team,s findings were published Thursday in ... Due ...
Breaking Biology News(10 mins):
(Date:1/17/2017)... Jan. 17, 2017   Pulmatrix, Inc . (NASDAQ: ... developing innovative inhaled therapies to address serious pulmonary diseases, ... infections in the lungs of CF patients, PUR1900, has ... by the U.S. Food & Drug Administration. ... to speed the development of novel drugs against important ...
(Date:1/17/2017)...  Only nine percent of U.S. consumers believe pharmaceutical ... 16 percent believe health insurance companies do, according to ... of U.S. adults believe health care providers (such as ... hospitals (23%). "We are in the midst ... , vice president of reputation management and public affairs ...
(Date:1/17/2017)... (PRWEB) , ... January 17, 2017 , ... Pono ... balanced, peaceful and healthy lifestyle, announced today the official launch of its much-anticipated Pono ... the mind. , In development for over a year, the patented Pono ...
(Date:1/17/2017)... ... January 17, 2017 , ... Diagenode, ... recently announced a collaboration with the Heidelberg University Hospital and the German Cancer ... preparation, following the company’s successful launch of its CATS (Capture and Amplification ...
Breaking Biology Technology: