CRASAR's search and rescue robots assist rescue workers at the World Trade Center

Citation

(2002), "CRASAR's search and rescue robots assist rescue workers at the World Trade Center", Industrial Robot, Vol. 29 No. 3. https://doi.org/10.1108/ir.2002.04929cab.001

CRASAR's search and rescue robots assist rescue workers at the World Trade Center

CRASAR's search and rescue robots assist rescue workers at the World Trade Center

Keywords: Robots

Within six hours of the World Trade Center disaster on 11 September, the Center for Robot Assisted Search and Rescue (CRASAR), a non-profit crisis response and research organization, responded with its diverse cache of robots from around the US certified and trained teams from Foster-Miller and iRobot (two private companies from the Boston area that manufacture some of the robots used), SPAWAR (US Navy), and the University of Florida brought a total of about 12 urban search and rescue (USAR) robots to Ground Zero to help support emergency workers and rescue dogs in their efforts to locate victims in the rubble (Plate 1).

Several types of remotely-operated robots were used in the operation by the four teams. Customized versions of the MicroTrac Inspection System and the MicroVGTV (variable geometry tracked vehicle), both manufactured by Inuktun, a Canadian company, were tethered into voids too small for human rescuers. These compact and rugged tracked crawlers were manoeuvred 30-50ft into piles of rubble. With their bi-directional audio and remote sensing, the robots helped the teams determine whether the area contained victims and was structurally sound. One of the MicroTracs sustained a damaged track, most likely from being melted in the subterranean fires.

The Solem, a vehicle made by Foster-Miller, was also deployed on the pile of rubble. The Solem is controlled through a two-way RF or fiber optic link from an attaché-sized operator control unit (OCU). The OCU displays video from up to seven cameras with audio and data feedback for precise vehicle positioning and control at distances out to one mile (1.6km). The suitcase-portable, 15kg Solem is equipped with drive wheel encoders, a three-axis compass and an arm potentiometer so the operator knows the vehicle's distance, heading and arm angle (Plate 2).

Plate 1 USAR robots prepare for operations at the World Trade Center (Photo courtesy of Center for Robot-Assisted Search and Rescue)

Plate 2 Solem-void inspection, Tower 2, 16 September 2001 (Photo courtesy of Center for Robot-Assisted Search and Rescue)

The Talon, another Foster-Miller robot, was used in the inspection of collateral buildings. Talon utilizes the same controls as the Solem, and can carry more than 90kg with a two-stage arm that can reach a maximum length of 1.6m and a gripper attachment to manipulate hazardous materials.

Other robots used for building search were the Packbot, manufactured by iRobot and sponsored by the Defense Advanced Research Projects Agency (DARPA), and Urbots. Packbot is housed in an impact-resistant aluminum shell that has a self-righting mobility platform that is equipped with tracked "flippers" to allow the robot to climb hills and stairs, and assumes an upright posture suitable for navigating narrow, twisting passages.

The Urbot is a low-profile tracked robot that is controlled by an operator via an RF link. It is fully invertible, completely waterproof, and employs four video cameras. Its small size (can fit through a 24in manhole) and excellent manoeuvrability make it ideal for sewer reconnaissance in the below-ground infrastructure.

The first two weeks focused on searching the rubble pile and neighboring buildings, while the second two weeks concentrated on inspection of the basement and slurry wall structure. Five bodies and one set of remains, but no survivors, were found in this first known use of robots for urban search and rescue.

For more information on the USAR robots used at the World Trade Center, visit CRASAR at www.crasar.org.