Eddy current damper feasibility in automobile suspension: modeling, simulation and testing

Abstract

This paper presents the modeling, simulation and testing of a novel eddy current damper (ECD) to be used in vehicle suspension systems. The conceived ECD utilizes permanent magnets (PMs), separated by iron poles that are screwed to an iron rod, and a conductive hollow cylinder to generate damping. Eddy currents develop in the conductor due to its relative motion with respect to the magnets. Since the eddy currents produce a repulsive force that is proportional to the velocity of the conductor, the moving magnet and conductor behave as a viscous damper. The structure of the new passive ECD is straightforward and does not require an external power supply or any other electronic devices. An accurate, analytical model of the system is obtained by applying electromagnetic theory to estimate the electromagnetic forces induced in the system. To optimize the design, simulations are conducted and the design parameters are evaluated. After a prototype ECD is fabricated, experiments are carried out to verify the accuracy of the theoretical model. The heat transfer analysis is established to ensure that the damper does not overheat, and the demagnetization effect is studied to confirm the ECD reliability. The eddy current model has 1.4 N RMS error in the damping force estimation, and a damping coefficient as high as 53 N s m−1 is achievable with the fabricated, scaled-down prototype. Finally, a full-size ECD is designed and its predicted performance is compared with that of commercial dampers, proving the applicability of the ECD in vehicle suspension systems.

Shunt Damping Vibration Control Technology: A Review

“…According to Faraday's law, the induced emf can be obtained [52] V e = (v × B)·dl (8) The electromagnetic force of the current-carrying element Idl can be obtained as [53] F e = Idl × B…”

“…v, I and Fe denote the relative velocity, the current flowing in the circuit, and the control force, respectively. Cm of the rectangle-shaped can be found in [52,53,55,56], the cylinder-shaped in [48,57], and the annular-shaped in [8,[58][59][60][61].…”

“…Some smart materials and structures that possess unique electromechanical characteristics have been widely used for active vibration control, such as magneto-rheological fluid damper [1], piezoelectric damper [2][3][4][5], shape memory alloy [6,7] and eddy current damper [8][9][10][11]. The active vibration control system consists of actuators, controllers, and sensors.…”

Z-Damper: A New Paradigm for Attenuation of Vibrations

“…In this way, the kinematic energy from the vibration can be dissipated and not transmitted to the structure. An arrangement of permanent magnets oscillating inside a conductive element is the most common design [12].…”

WEIS wheel speed real-time measuring method for VOSM

“…It is one of the most important parameters of wheel safety monitoring [2]. For existing wheel speed measuring methods, an independent speed sensing system is fixed on the wheel to measure a single parameter, such as magneto-electric type [3], eddy-current type [4], and hall element type [5]. Recently, other wheel speed measuring methods have been put forward, i.e., a new wheel speed sensor method was proposed to encapsulate the sensor in the clearance between the lateral ring and the outer ring in the hub in Ref.…”