Sensor applications expand

Intelligent sensors are being used in a growing variety of applications, to control and monitor everything from indoor temperature to machinery, access and even safety.

It was the Challenger disaster which provided the case from which researchers at the Massachusetts Institute of Technology developed new methodologies for how to pre-empt major accidents.

MIT’s STAMP (Systems-Theoretic Accident Model and Processes) depends on the assumption that there are no simple linear causes. “Accidents arise from complex interactions among humans, machines and the environment which are hard to predict,” says MIT’s SENSEable City Lab team leader Stephen Miles.

The MIT lab is exploring ways to combine RF identification with sensing and tracking technology to ensure safety and security on a major construction site.

The Italian utility company ENEL has called them in to help design systems to ensure efficient safety and security procedures for the 2.8 billion euro expansion of a nuclear power station at Mochovce, Slovakia, which should provide 20 % of the country’s electricity by 2014.

Sensors for safety

“We’re investigating how advanced sensing and tracking technologies can provide decision support,” says Miles, whose MIT group is providing technological answers to the kinds of questions which utility safety managers might ask.

“There may be 4,000 people on site – all engaged in different construction activities,” Miles points out. “So we start from a model of what is scheduled to happen, integrate it with a computer-based model of the site, and provide tools to allow safety planners to move activities around to mitigate risk.”

An integral part of STAMP is the implementation of constraints in monitoring each control system. Through sensing technology, workers can be alerted to dangerous situations, which can be defined by the technology itself. If a bio-sensor, attached to a worker’s personal protective equipment, sends an alert that the worker has slipped, action can be taken to investigate, and, if necessary, to close that area. The closure may be physical, or it may be a warning on a smartphone.

“We can sense things very cheaply, and we have the technology to measure all kinds of constraints like temperature, distance or pollution,” says Miles. “The site’s safety experts know which constraints are important to them, and thus which we need to monitor.”

As a construction site progresses security requirements change. While personnel and equipment in a greenfield site can be monitored using GPS, once buildings have roofs, RFID readers will have to be deployed. Each day, different material, logged in electronically, will have to be tracked in different places and handled by various people.

“What’s so exciting now is that we have ISO standards for physical layer wireless connectivity at LF, HF, UHF, WiFi, ZigBee and UWB frequencies so that we can leverage a common reader infrastructure for new applications,” says Miles.

Accessing the way

There’s plenty of potential in combining the information on access cards with the other information a company holds. For example, if a Cisco staff member visits a Cisco Executive Business Center to meet a customer, says Lindsay Hiebert, senior manager for Physical Security Marketing in Cisco’s Central Marketing Organization, Cisco is able to demonstrate new integrated capabilities so that when the staff member badges in, he or she could be presented with a map of the building indicating how to get to the meeting room.

“Access control, staff calendars, the Center’s room allocations and the building floor map all have to be integrated,” he explains.

Dennis Charlebois, director of Safety & Security Solutions at Cisco, suggests a further development: “When I walk in, my identity is passed to the network access office, and the ports in my office are released.”

IT security is of course a matter of serious concern, and much of the threat comes from physical insecurity, so locking network access when the authorized user is not in the building makes sense. But one could go further still.

“If a CFO badges in to the building and logs in to the network, he gets full access,” suggests Charlebois. “But if he hasn’t badged in, he’ll only get access to certain parts of it: he may be sitting in a Starbucks using an insecure Wi-Fi, and you wouldn’t want the company’s figures going over that.”

So far the main sensor used in access control is the RFID card, but smartphones could change all that. Hiebert notes that the CIO of the French town of Drancy, a Cisco customer, has moved on to a next generation.

“He mapped his access control privileges onto his iPhone using regular apps,” says Hiebert,” and now he doesn’t have to carry keys anymore.”

The SENSEable Lab is using smartphones both for geo-positioning and as a kind of “voluntary sensor”. If someone sees a safety hazard, they photograph, geo-tag and upload it immediately, or if the sensors pick up unusual activity an alert is sent to teammates or a supervisor. The opportunity, says Miles, is to make safety risk management engaging and “more democratic.”

By Michael Lawton


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