This structure is not classified as dangerous machine. But since the robot is designed to move through people and since its mass is around 120Kg, any dysfunction must be avoided. For the security, neither the hardware nor the software is completely reliable, therefore the SUVA recommends that every security system must be redundant.

In this robot, the first security system is the PowerPC, which is continuously watching all the process such as obstacle avoidance and speed control. The second system is a separate electronic card that continuously watches the speed of the wheels, their torque and the state of the bumpers. The two systems are also watching each other in case of a malfunction.

The motors are connected to the amplifiers through relays. When the robot is turned off, the relays are released and shortcut the windings of the motors (brake state). The relays are only opened when necessary and as long as every security system allows it. A red security button located on the base of the robot can also deactivate the relays.

Developper@ASL:
- Ralph Piguet