Design of an active magnetic wheel with a varying Electro-Permanent Magnet adhesion mechanism

Magnetic adhesion mechanism is commonly used in mobile robots design for inspection tasks of ferric structures. The magnetic adhesion force is generated either by Permanent Magnets (PMs) or Electro-Magnets (EMs). Both methods have intrinsic limitations: fixed magnetic force in PMs or a constant electric power supply in EMs. Work in this paper presents a novel active magnetic wheel design by implementing Electro- Permanent Magnet (EPM) technology in its adhesion mechanism. EPMs allow to control the magnetic force by simply applying a short electric pulse. Controlling the amplitude of the electrical pulse, the magnetic force can be set into a chosen value enabling a continuous variation of the magnetic adhesive force. Implementing EPMs in adhesion mechanism will impact significantly on the mobile robot when manoeuvring in complex structures, avoiding difficult obstacles and energy consumption, thus enhancing its performance. Simulations of the proposed wheel design are performed in order to demonstrate the behaviour of the active magnetic adhesion mechanism and its feasibility. An improved design of the actual wheel is presented based on results of initial simulations. Further designs are suggested by adapting the adhesion mechanism to existing wheel designs.