Conflicting signals can confuse rescue robots

March 2, 2007

Sensor-laden robots capable of vital search and rescue missions at disaster sites are no figment of a science fiction writer's imagination. Prototypes and commercial models of urban search and rescue (US&R) robots will soon begin to work rubble piles across the country. Too many of these lifesaving robots, however, could be too much of a good thing, according to researchers at the National Institute of Standards and Technology, who report that the radio transmissions of multiple robots can interfere with each other and degrade search and rescue performance.

A NIST analysis of wireless radio field trials for US&R robots, presented at a conference on February 28, found that 10 out of the 14 robots tested experienced communication problems due to radio interference from other systems. Engineers carried out tests on the robots last August at a US&R robot standards development gathering in Gaithersburg, Md., sponsored by the Department of Homeland Security.

The researchers found that neither use of "industrial, scientific, and medical" (ISM) frequency bands nor adherence to protocols designed to minimize interference between systems in the bands could guarantee flawless communication between a robot and its human operator. Radio interference could happen whenever the ISM frequency bands became crowded or when one user had a much higher output power than the others. An example of the latter problem occurred during the tests when transmitters in the 1760 MHz band knocked out video links in the 2.4 GHz frequency band. In another case, a robot using an 802.11b signal in the 2.4 GHz band overwhelmed and cut off a robot that had been transmitting an analog video link at 2.414 GHz.

The NIST paper lists a number of ways to improve urban search and rescue wireless communications. Options, some of which are currently being investigated by robot manufacturers, include changes in frequency coordination, transmission protocols, power output, access priority, and using relay transformers to increase the range of wireless transmissions (a technique known as multi-hop communications). The paper also suggests establishing new access schemes or software-defined radios that allow interoperable communications.

Ref.: K.A. Remley, G. Koepke, E. Messina, A. Jacoff and G. Hough. Standards development for wireless communications for urban search and rescue robots. 9th Annual International Symposium on Advanced Radio Technologies, Feb. 26–28, 2007, Boulder, Colo.

Source: National Institute of Standards and Technology

Explore further: Two-armed drones developed to help with hands-on tasks

Related Stories

Two-armed drones developed to help with hands-on tasks

September 21, 2016

(Tech Xplore)—Drones are good for things other than delivering pizzas and sneakers for sure. We are reading more and more about applications intended for public services, for farming, engineering and security operations ...

Single actuator wave-like robot developed

August 1, 2016

The first SAW (Single Actuator Wave-like Robot) that produces a pure wave motion using a single motor has been developed at Ben-Gurion University of the Negev. The SAW robot is designed for medical applications, maintenance, ...

Recommended for you

Microsoft aims at Apple with high-end PCs, 3D software

October 26, 2016

Microsoft launched a new consumer offensive Wednesday, unveiling a high-end computer that challenges the Apple iMac along with an updated Windows operating system that showcases three-dimensional content and "mixed reality."

Making it easier to collaborate on code

October 26, 2016

Git is an open-source system with a polarizing reputation among programmers. It's a powerful tool to help developers track changes to code, but many view it as prohibitively difficult to use.

Dutch unveil giant vacuum to clean outside air

October 25, 2016

Dutch inventors Tuesday unveiled what they called the world's first giant outside air vacuum cleaner—a large purifying system intended to filter out toxic tiny particles from the atmosphere surrounding the machine.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.