Archive for January, 2018

Top 5 Surprises in Unmanned Systems for Mudslides

CRASAR's Sam Stover and Robin Murphy at 2005 La Conchita, California, mudslides

CRASAR’s Sam Stover and Robin Murphy at 2005 La Conchita, California, mudslides

I’ve been getting questions about the use of unmanned systems for the recent horrific Montecito mudslides, so let me extend my earlier tweet, both in terms of thoughts and prayers to the victims and also the technical details. It does not appear that small UAS are being used by the formal responders for Montecito.

  1. Unmanned systems- ground and aerial- have been used since 2005 and there are opportunities for marine systems as well. Unmanned systems have been used at least three times in the United States for landslides, two by CRASAR teams. UGVs were used for the 2005 La Conchita, California mudslide (which was the first ever use of an unmanned system for a mudslide), while UAS were used for the 2014 Oso, Washington, and Collbran, Colorado, mudslides. Both fixed and rotorcraft UAS were used at Oso and Collbran.At Oso, it would have nice to have had an autonomous marine vehicle with sonar to map the underwater portions. See  this paper  on the 2005 La Conchita and blog mudslide and  2014 Oso mudslide plus more lessons learned are in Disaster Robotics and in our older blogs. Plus see video Oso composite of small UAS flights 
  2. The primary use for UAS has been for reconnaissance and mapping, not life safety. In the La Conceit mudslide, CRASAR worked with Ventura County, Los Angeles County, and Los Angeles City fire departments using shoe-boxed sized ground robots to try to get through basement voids and narrow windows in order to search collaterally damaged buildings for a missing family. Search dogs had given ambiguous indications but it was too dangerous to send in a human responder and the dogs couldn’t squeeze in. The robots weren’t used in the primary mudslide area because this type of mud had penetrated every house in its path leaving no pockets  and would require a burrowing robot such as the sand lizard styles being researched by Dan Goldman and Howie Choset. In the Collbran (Deputy Sheriff Ben Miller at Mesa County used their systems) and Oso mudslides (The Field Innovation Team/CRASAR team worked under the direction of Snohomish County), the UAS were used for gathering essential elements of information about the disaster area and assessing the situation. This includes determining the boundaries of the disaster area; access points to the disaster area; social, economic and political impacts (e.g., at Oso there were concerns about additional property damage and impacts on salmon); geophysical information (e.g., topology and volume of debris); projecting impacts; and initial needs and damage assessment. The Montecito mudslides illustrate that another EEI, assessing the status of transportation systems— what roads and trails were still open to get responders in and civilians evacuated, is also important. The UAS at Oso and Collbran also allowed the incident commander to see where teams actually were and also ensure that unauthorized personnel weren’t entering the cordoned off area.
  3. A UAS platform that can perform only autonomous mapping is highly limited for the immediate response. Both Oso and Collbran had missions that required first person view/manual flight where experts could direct the UAS in real-time in order to better assess the situation. At Oso, the PrecisionHawk Lancaster was extremely valuable in rapidly mapping the disaster, but the responders also used the AR100B quadcopter to hover and stare over the water to estimate flow rate, locate personnel, determine progress on mitigation efforts, and generally get closer looks at objects and activities that they didn’t know that needed to look at until they saw it from the air.
  4. The biggest unanticipated UAS challenge has been flying mapping missions in complex terrain, not endurance or distance. While having a UAS with the endurance and capability to cover an entire mountain from a single launch point is important, the limitations (and LOS regulations) are well-understood by the UAS operators. The unexpected problem was the complexity of the terrain. The autonomous mapping software programs assumed a flat earth, suitable for agricultural mapping but the areas of interest were in the “toe” of a mountain and a plain. The elevation of the landscape varied. In addition, the landscape had forests with some trees higher than others. This presented challenges for autonomous mapping, especially as it was desired to fly the UAS as low as practical in order to get the high resolution imagery.  The operators had to create “stair steps” missions for fixed-wings and vertical slices for quadcopters. In Oso, the CRASAR team used a quadcopter to fly to the tallest tree in a “patch” and get the actual height so that the fixed-wing could be programmed to stay well above that height. The advances in obstacle avoidance by DJI would have been very helpful.
  5. Protecting personal identifying information (PII) and privacy has been the biggest barrier in deployment. Data management and chain of custody has long been a requirement of unmanned systems use by formal response agencies. The Oso mudslides illustrated how touchy PII and privacy can be. At the Oso Mudslides, UAS operations were suddenly cancelled due to concerns over victim privacy; this was later resolved when the incident command staff was able to clarify that the UAS would be flying over the “toe” of the mudslide and river and not where victims were being recovered.  Ironically, the FIT/CRASAR team had talked to all the local property owners to assure them that the UAVs would not be flying over their land and any recorded imagery would belong to the county and released only with their permission.

If you have documentation on other deployments of unmanned systems to landslides, please send me the info and I’ll send you a CRASAR patch!