Adapted magnetic wheel unit for compact robots inspecting complex shaped pipe structures

This paper describes a novel magnetic wheel unit integrating a mechanism that can be used for lifting and stabilizing the unit. The mechanism consists of 2 active lever arms mounted on each side of the wheel and rotating coaxially with the wheel. This mechanism allows slightly lifting the magnetic wheel at any desired position on the wheel circumference and consequently decreasing the magnetic force at this specific location. The same mechanism can also be used to stabilize the wheel, when external forces are unfavorable. This paper also describes the potential of this concept for in-pipe inspection technologies. Indeed it can be used to increase the mobility of magnetic wheels robots which are currently not able to negotiate complex obstacles. At the same time, it allows building smaller robots, since the self stabilizer system allows reducing the amount of required magnetic wheels to only two units.