The Alicia VTX is a new climbing robot that use a smart active suction cup, built upon an idea of Duke University. The vacuum inside the cup is generated by means of a high speed centrifuge fan that create a vortex with a low pressure area in the central zone. By using this principle it is possible to use a low power brushless motor to actuate the fan (about 50W). Moreover no exhausts are generated, so the process is more efficient with respect to suction cups where an aspirator is used instead to generate the vacuum.
This kind of vacuum cups can adhere to different kind of rough surfaces because it can sustain vacuum inside also in the case when the cup is not in contact with the surface. This allows to reduce to zero the friction between the cup and the wall, to save energy, to increase robot speed, allows the robot to move over small obstacles or irregularities and to climb from a floor to a wall while maintaining high payloads (about 1.5 kg).
The robot use four wheels with four independent DC motors to move along the surface and use an inclinometer as feedback sensor in order to follow a reference trajectory. Moreover a wireless CCD camera is mounted on-board. Different tests about the cooperation between the Robovolc rover and the Alicia VTX were performed in order to investigate the possible use of the two in outdoor environment in critical situations where human operator can't reach the target vertical wall and can't perform visual inspection for safety or rescue purpose.