Beginning with the World Trade Centre disaster in 2001, rescue robots have been increasingly deployed into disaster areas. However, although many solutions have been suggested and designed, rescue robots have never become commonplace in rescue operations. Various rescue robots have been designed, each having varying levels of success. The relevant literature argues that a low cost robot that is rugged and simple to operate could be integrated into all areas of rescue teams and could become instrumental in providing rapid deployment of rescue robots at disaster sites.
In 2002, Murphy, Blitch and Casper proposed the most basic level of robots for AAAI/RoboCup, which are teleoperated and able to navigate through rubble and conﬁned spaces. Mapping and planning would all be carried out manually by the operator with a visual user interface that can display multiple sensors simultaneously. The sensors are able to detect the basic affordances of a survivor: heat, motion, sound, and color. Any rescue robot should adhere to these speciﬁcations and the actions of rescue operators should not be swayed by the fear of losing the robot. In order to achieve this the robot must be considered to be “expendably cheap”.
In order to make the robot both affordable and rugged it has to be simple in design. In order for the robot to navigate through small voids it has to be as compact as possible. With both of these considerations in mind the Robotics and Agents Research Group at the University of Cape Town designed Scarab. The design intent for Scarab was to create a small, rugged, cost-sensitive robot with a very simple user interface.
Scarab is designed to be rugged, low cost and human packable. It is approximately the size of a shoebox, 3kg in mass and is designed to withstand a drop from up to 3m. The embedded tail not only acts as an aerodynamic surface to stabilize the robot during ﬂight, but also as the grip for the throwing action. It is a two-wheeled robot with independent drive where the tail drags along the ground and constrains the pitch of the body. The robot is designed to be deployed by being thrown into a building and its navigation strategy is to tumble from higher ﬂoors to lower ones. In the front of the robot is an interchangeable sensor payload which allows for increased sensor ﬂexibility by accommodating any number of purpose-built sensor payloads. Scarab is controlled with a small sized handheld controller. All the buttons are designed to be operated by the hand holding the controller and are large and rugged enough to be operated even when wearing gloves. Sensor information such as battery percentage, temperature and GPS coordinates are displayed onscreen. The operator is able to modify these settings should they desire. Additionally, the on-board display can be sent to a pair of FatShark goggles that will give the user a ﬁrst person view of the rescue scenario. The total cost of the hardware for Scarab is USD 500, more than 15 times less than a similar commercial product. It is estimated that with assembly and mass manufacture the cost will remain under USD 1000.