Robots for Search and Rescue
Search and rescue is multi-faceted. At this time CRASAR has focused primarily on urban search and rescue (man-made structures), though we are examining mine disaster rescue, transportation, and wildfire. Within USAR robotics, there are two philosophies. One is to build big robots to speed up excavation, essentially roboticizing construction equipment and work from the exterior of the rubble pile to the interior. The other is to build small robots to get deep (20 to 300 feet) into the interior. This figure shows the taxonomy of size of robots to the voids they are best suited for. See below for details on what we considered the requirements for a USAR robot.
CRASAR maintains a cache of 13 "micro" ground robots and sensors with trained responders which is kept on constant standby 24/7. The response team participates at no charge. Unmanned aerial vehicle assets are also available. The response team is funded through grants from the National Science Foundation, Department of Transportation, Florida High Tech Corridor, SAIC, Inc., and the Safety Security Rescue Research Center. Follow this link to learn more about our cache and response team. What We Look for in a Ground Robot System for USAR
CRASAR has been working to determine the desirable characteristics of robots for USAR. This section attempts to distill our published recommendations and observations from our field exercises. CRASAR is also a member of the NSF industry/university cooperative research center on Safety Security Rescue (SSR-RC) and is working with their Standards Support Committee to provide information to standard developing organizations. We consider a Robot System to consists of robot base, OCU, transport container(s), backpack, camcorder, any recharging equipment, tools needed for simple repairs, and spare parts. The system as a whole needs to be
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carried in 1 backpack (safely carried, not jammed in a backpack with an awkward center of gravity or too heavy. We currently use LA Rescue Gear system and customized EVAC packs), can be set up in <5 minutes with gloves on, and kept on warm standby while being transported. Note: 1.5 minutes at WTC was limit of attention, which led to a “Ghostbusters”-like deployment: the robot was on and the operator would reach around back to grab the robot and deploy it.
- Shippable as check-through luggage on airlines. (e.g., electric motors are much easier to get on an airplane than gasoline-powered engines). Transportable via check-through luggage airlines within international weight restrictions. International weight restrictions are far more restrictive than US standards. Ideally the entire robot system would fit in 1 pelican case weighing <60 pounds. Otherwise, there’s a good possibility that you won’t have a whole system, just part of one, when you need it.
- Operable in total darkness as well as direct sunlight. This isn’t just a display issue, we’ve had numerous robots and OCU overheat within a few hours of working in the sun. Remember, the ground temperature near the surface of a grassy lawn on a sunny day can exceed 140 deg. F– imagine the heat of concrete under the same conditions!
- easily decontaminated, both field deconned and a complete decon. The robot will be operating in areas soaked by sewage, water, and even bodily fluids from victims. The robot has to be reasonably cleaned up before inserting in the next void and very thoroughly decontaminated at the end of the shift.
- provide APIs for software development. Otherwise the platform won't support interoperability and the addition of new functionality.
Every robot should carry the following as a minimum (plus have the ability to carry other sensors, payloads as described below):
- Basic components:
- Color video camera with zoom,
- 2 way audio (both for communication and to help diagnose problems with the platform),
- lighting (prefer LED over halogen to reduce possibility of ignition in an explosive atmosphere).
- Note: B&W isn’t as useful as color because the dominant cue is color– anything that isn’t gray is important to look at. We'd prefer to take a color image and do computerized image enhancement rather than use B&W
- There should be a point to attach a safety rope for a wireless robot or the tether should be sufficient to serve as a safety rope.
- The robots should be waterproof, as in total immersion when it goes “plunk” into a deep puddle, and waterproof for cleaning with garden hose pressures, about 8 cfs), not merely water resistant.
- Ideally the robot should be invertible or self-righting. Of course, invertible robots are able to run upside down only if there is no sensor payload. Self-righting doesn’t work well in highly confined spaces.
- The platform must read temperature of surroundings, since human safety, structural understanding, robot survivability depend on this.
- The system should have a MTBF 96 hours (this is the minimum acceptable for military robots as established by Ft. Leonard Wood, though the current best is 20 hours).
- Robots should meet ISO 9001 so that we’d get the same performance for all robots of a manufacturer and model- we’re seeing too much variation.
- Highly visible color for all components. This is for many reasons- convenience in locating the robot, visual check on cleaning, less creepy to survivors (you can’t see a black robot in the dark which is disconcerting because you can see the headlights and hear it whirring close to you), and yellow or orange is standard for safety equipment.
- Mobility and platform. The effectors must minimize dust being kicked up and noise. (This is especially true for micros which operate around victims- there’s usually a lot of dust present which causes respiratory problems for survivors). No dangling wires, surfaces that would catch or hang. The robot should give indication of the physical configuration of the robot (position of tilt of cameras, whatever effectors are extended, etc.).
- Tethers. Tethers must be quick disconnect for safety (the operator may have an emergency evacuation off the pile). And, as a result, it is desirable to be able reconnect with the power still on without frying electronics to compensate for inevitable human error. As noted earlier, must be sufficient to serve as a safety rope, otherwise there are now two lines to tangle.
- Wireless. The robot should provide an indication of wireless communications strength in some way amenable to actually help the operator anticipate a comms failure before it happens. It would be desirable to reverse last movements to attempt to restore when comms are lost beyond a time limit.
The OCU (operator control unit) for a robot should:
- Be set up for two person viewing and audition (our studies show that two operators working together are 9 times more likely to find a victim than a single operator)
- Record and playback the sensor data on-site so we can go back and re-examine what we’ve seen. Note: we typically use a camcorder to provide the 2nd person view and record, but that doesn’t let the 2nd person talk.
- OCU or robot “black box” to record temps, actions, video, etc., allowing reconstruction of what the robot was doing or had seen
- Maximize viewing area (PDAs are too small for primary navigation screen).
- Set up for incorporation of sensor payloads, and display the output in some fashion
- Display work in bright daylight and night, able to function in heat/cold outdoors, and in the rain/snow
- Display not interfere with personal protection equipment (e.g, helmet, gloves, safety googles, respirator)
- Connector for computer and APIs that allow computer control
- The robot system should be able to function in these operating conditions:
- Smoke, water, significant dust and water vapor suspended in air, biohazards including fecal material, dirt, mud.
- Go through high heat, extreme cold on way to survivable void. (Given that the average search of a void appears to be on the order of 20 minutes, wouldn’t expect the robot have to be in extreme temperatures for longer than 20 minutes, though if a victim was found, a tethered system would have to have the tether reside in those conditions. This is where the external temperature detector comes in handy so that the impact of the environment can be factored in.)
- A possibly explosive environment (e.g., either build in a detector or make it intrinsically safe– which may be impossible).
- Under radiological exposure. There should be some way to estimate impact of radiation and provide for graceful degradation, field replacement of key parts (e.g., replaceable CCD camera head).
Desirable Payloads and Mission Characteristics
In general:
- Robots should be able to supply/share on-board power with sensors or sensors must be self-contained and subject to same use profile as with platform. Of course, the later means that the sensor will be bigger and heavier, which is not desirable, so we favor robot platforms that provide power.
- Sensor payloads in general should be
- Hot swapable.
- Swapable between manual, wand, UGV, UAV, vehicle mounted deployment.
For the structural investigation mission:
- Way to measure or estimate distance from video. Right now, we’re reduced to using two laser lines at a fixed distance since laser rangers are too large to fit on the micro class of man-packable robots.
- Zoom on the video is absolutely essential.
- Note: Ground penetrating sensors, 3D mapping are desirable, but no systems exist for micros at this time.
For the search mission:
- Additional sensors (can’t do without color video) that appear very useful are: Pursuit vision (a type of active night vision) which gives a “spotlight” on the surroundings and FLIR which helps locate heat sources (victims or an incipient flashover). FLIR is very hard to navigate by, so it would never replace the color video with lighting.
- On a search mission, expect to operate >20 minutes on a charge and run 4 times in 12 hours from gear in backpack for search.
- Desirable to have built in sensor for oxygen level. This is needed for human safety, assessment of survivor viability
- Note: Ground penetrating sensors, 3D mapping are desirable, but no systems exist for micros at this time.
For the HazMat mission:
- The Multirae (Oxygen, explosive atmospheres) and APD2000 (radiation) are the standard sensors- if a platform can’t support them, then the robot just won’t be that useful.
For the medical mission:
- Operate 10 hours continuous if medical mission (maintains communication with victim during extrication with is 4-10 hours cite)
- Additional sensors: Radiance Life Check triage sensor appears very promising for telling whether a vicitim is unconscious or dead.
- Mechanical payload attachment- drop off blanket, food rolled into a waterbottle sized container (3” diameter)
- Mechanical payload attachment- Tubing for water, air that can be disconnected from robot/tether so that the robot can move around without taking water or air away from the patient.
- Mechanical and electrical attachment for other sensors in the field , data should be displayed on OCU (e.g., FLIR or a serial device such as a hazmat sensor)
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