Abstract-This paper offers motivations for an electromagnetic active suspension system that provides both additional stability and maneuverability by performing active roll and pitch control during cornering and braking, as well as eliminating road irregularities, hence increasing both vehicle and passenger safety and drive comfort. Various technologies are compared with the proposed electromagnetic suspension system that uses a tubular permanent-magnet actuator (TPMA) with a passive spring. Based on on-road measurements and results from the literature, several specifications for the design of an electromagnetic suspension system are derived. The measured on-road movement of the passive suspension system is reproduced by electromagnetic actuation on a quarter car setup, proving the dynamic capabilities of an electromagnetic suspension system.

Abstract-This paper offers motivations for an electromagnetic active suspension system that provides both additional stability and maneuverability by performing active roll and pitch control during cornering and braking, as well as eliminating road irregularities, hence increasing both vehicle and passenger safety and drive comfort. Various technologies are compared with the proposed electromagnetic suspension system that uses a tubular permanent-magnet actuator (TPMA) with a passive spring. Based on on-road measurements and results from the literature, several specifications for the design of an electromagnetic suspension system are derived. The measured on-road movement of the passive suspension system is reproduced by electromagnetic actuation on a quarter car setup, proving the dynamic capabilities of an electromagnetic suspension system.

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In the high-precision industry, accurate vibration isolation and magnetic levitation are extremely important. As a result, high-performance vibration isolation and magnetic bearings based on permanent magnets are increasingly considered. This paper proposes improved analytical expressions for the torque on cuboidal permanent magnets applied to a magnetic bearing. These novel expressions are valid for any relative magnet position, especially when surfaces of the different magnets are in the same plane. Further, the torque can be obtained with respect to any reference point. Although these equations seem rather complicated, they enable an extremely fast and accurate calculation of the torque on a permanent magnet in the presence of a magnetic field of another permanent magnet. These properties enable a fast design and optimization process of such bearings using fully analytical expressions.

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A control strategy of combining H control and feedback linearization was applied to the model of a highly nonlinear, three Degrees-Of-Freedom (DOF) electromagnetic actuator, which was recently designed for non-contact suspension of a large payload. The new electromagnetic actuator has the advantage of passive gravity compensation based on permanent magnets with low stiffness and high force density. But the nonlinearity is so high that the stability status along each DOF changes while the translator is traveling within the working range. Feedback linearization method was used to compensate the nonlinearity, a stabilizing controller was employed to eliminate the slow-varying calculation error of the passive force, and an H controller was designed for vibration isolation. Simulation results show that the proposed control strategy has robust vibration isolation performance within a working range in which the relation between the magnetic force and the relative position is highly nonlinear.

Abstract-Analytical methods for the calculation of the magnetic field such as the surface charge method offer high accuracy at a reduced calculation time compared to the Finite Element Method. However, for the surface charge model the relative permeability of the permanent magnets is assumed to be equal to air, µr = 1, thus an error is made in the calculation of the magnetic field strength of the magnet. In this paper the relative permeability of the magnet is taken into account in order to obtain an exact solution for the magnetic field. The interaction force between two magnets is calculated using the newly obtained expressions for the magnetic field.