Researchers at UCLA and partner universities have developed a new class of aerial, suspended robotic sensors able to monitor their own performance as they move themselves along a network of cables. The technology, known as networked infomechanical systems (NIMS), can be used to monitor a mountain stream ecosystem from the ground to the treetops for global change indicators, or observe coastal wetlands and urban rivers for biological pathogens. The same technologies could one day be applied to securing and monitoring public spaces such as ports and bridges. Beginning in October, the five-year project will receive $7.5 million from the National Science Foundation through an Information Technology Research grant. As a new research area in the UCLA NSF Center for Embedded Networked Sensing (CENS), it engages a large multidisciplinary team of scientists and engineers. Partner institutions include the University of California, Riverside; University of California, Merced; and University of Southern California. The project is led by UCLA electrical engineering professor Bill Kaiser, a CENS team member in the UCLA Henry Samueli School of Engineering and Applied Science. At the UC James San Jacinto Mountains Reserve (part of the University of California Natural Reserve System), a NIMS test bed will be deployed to collect dense environmental and ecological data about populations of rare species and their habitats within a mountain stream ecosystem and the surrounding conifer forests and meadows. The sampling protocol that allows NIMS to collect and bring samples to the lab autonomously will allow researchers to monitor and measure short-lived, intense events in the environment as they occur. “NIMS will build upon the existing CENS habitat-sensing infrastructure of fixed wireless embedded network sensors to augment, and in many cases dramatically enhance, the range of variables being measured within the complex plant communities and wildlife habitats of the James Reserve,� said Michael Hamilton, James Reserve director and assistant professor of Conservation Biology at UC Riverside. The NIMS infrastructure consists of a collection of steel cables, each attached to any two points — buildings, trees or other natural structures — that serve as suspension points. Nodes suspended on the cable collect data about the environment through a range of sensors that can be lowered or elevated, and also move, activate and recover fixed nodes set along the cable pathway. They also have the ability to dock when necessary to recharge their energy source, removing energy constraints that have hobbled other sensor networks in the past. According to Kaiser, NIMS addresses long-standing problems with current wireless sensor network technology, including energy constraints, scalability and obstruction by physical objects in a real-world environment. “We have developed NIMS to address these challenges directly,� Kaiser said. “The system allows us to introduce the physical reconfiguration that is necessary for adapting physical sensors. We can add new sensors and move sensors in such a way as to allow us to actually measure sensing uncertainty.� NIMS offers researchers other new capabilities as well. “NIMS devices can collect and transport physical samples from the environment, which means researchers are no longer limited to sensing only with in-situ devices,� Kaiser said. “We also plan to exploit NIMS’ ability to replace, relocate and replenish fixed nodes.� The project is part of the Center for Embedded Networked Sensing, where researchers are developing embedded networked sensing systems and applying this revolutionary technology to critical scientific and social applications. Like the Internet, these large-scale, distributed systems, composed of smart sensors and actuators embedded in the physical world, will eventually infuse the entire world, but at a physical instead of a virtual level. “What NIMS brings to CENS is both figuratively and literally a couple of new dimensions,� said Deborah Estrin, CENS director and a computer science professor at UCLA’s School of Engineering. “We’ve been looking at problems in which sensors are placed in two-dimensional space. NIMS — elevated above the surface — offers three-dimensional sensing solutions.� The NIMS team draws on the expertise of researchers at several top-tier universities in Southern California. Gaurav Sukhatme, director of the Robotic Embedded Systems Laboratory at the University of Southern California, is interested in multi-robot systems and how robots can coordinate their activity as a team to perform a task efficiently. “The sensor system requires a degree of autonomy — not only to reduce the amount of oversight required, but also because the operator doesn’t necessarily know where to look,� Sukhatme said. “If coordination isn’t done well, all of the nodes could end up in one location and entirely miss other items of interest in another part of the ecosystem.� The NIMS project promises to open up a host of new research opportunities in public health applications and in the natural environment. UCLA researchers intend to create a NIMS infrastructure that can be available to and adapted by other researchers to suit their applications. “Too often, we cannot address important research questions because of our inability to sample the right thing at the right time and place,� said Richard Ambrose, director of the UCLA Environmental Science and Engineering Program. According to Ambrose, NIMS has the potential to enable continuous, sustainable monitoring of coastal water zones, collecting data on critical pathogen sources and how water-system dynamics affect the fate of pathogens. Current monitoring efforts rely on manual sampling taken at intermittent intervals. The NIMS team completed a test installation at the Wind River Canopy Crane Research Facility in Washington this summer. Kaiser and a group of students rode in the gondola of a large crane to suspend cables, solar panels and an aerial sensor between two trees approximately 150 feet above the forest floor. “Using the prototype version, researchers will be looking at the complexity of an old-growth stage within the canopy,� said Ken Bible, research coordinator at the Wind River Canopy Crane Research Facility. “A lot of what they’ll be monitoring is basic forest ecology — for instance, using infrared imagers to track forest temperatures and heat patterns. NIMS’ embedded sensor design will provide practical information to the researchers, who will need to find ways to distill it for the policy makers and managers.� The CENS team hopes to extend the work to sites in other areas, such as the La Selva Biological Station in Costa Rica. Philip Rundel, a professor in the UCLA Department of Organismic Biology, Ecology and Evolution, and a founding faculty member with CENS, said, “NIMS will allow us to collect spatially and temporally dense measurements across the forest floor and canopy — information that is vital to understanding the impact of the environment on the diversity of species in the rain forest.� For more information about CENS and its partners in the NIMS project, visit:
· Center for Embedded Networked Sensing: www.cens.ucla.edu/
· UC James San Jacinto Mountains Reserve: www.jamesreserve.edu/
· Wind River Canopy Crane Research Facility: depts.washington.edu/wrccrf/
· Robotic Embedded Systems Laboratory: www-robotics.usc.edu/~embedded/