IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 59, NO. 3, MARCH 2010
Active Electromagnetic Suspension System for
Improved Vehicle Dynamics
Bart L. J. Gysen, Member, IEEE, Johannes J. H. Paulides, Member, IEEE, Jeroen L. G. Janssen, Member, IEEE, and Elena A. Lomonova, Fellow, IEEE
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.
Index Terms—Active suspension, permanent magnet (PM),
I. I NTRODUCTION
DVANCED electromechanical and electronic systems are
used to inﬂuence the dynamic performance of the vehicle,
for example, antilock braking systems, electronic break force distribution, electronic stability program, etc. These systems improve vehicle handling and passenger safety, since this becomes an ever-increasing demand for the automotive industry, particularly when cars tend to become smaller (SMART) and
incorporate a higher center of gravity (sport utility vehicle) and a reduced footprint. For instance, the Transportation Research Board  reported that 51% of serious car accidents are caused by rollover. Another trend in the automotive industry is the “more electric car,” e.g., the Toyota Prius. These hybrid vehicles combine the efﬁciency of an electric motor and an internal combustion engine. Due to the global increase in oil prices
and the importance of environmental sustainability, the “full electric car” is also gaining attention. Recently, a Dutch energy company (Essent), together with Electric Car Europe , has launched a commercial electric car. These cars have a totally different weight distribution since the combustion engine is replaced by an electric motor and a battery pack that weighs around 400 kg. As such, the optimal electrical drive train efﬁManuscript received January 19, 2009; revised May 18, 2009, July 17, 2009, and October 9, 2009. First published December 18, 2009; current version published March 19, 2010. This work was supported by SKF. The review of this paper was coordinated by Prof. J. Hur.
The authors are with the Department of Electrical Engineering, Eindhoven University of Technology, 5600 Eindhoven, The Netherlands (e-mail: email@example.com).
Color versions of one or more of the ﬁgures in this paper are available online at http://ieeexplore.ieee.org.
Digital Object Identiﬁer 10.1109/TVT.2009.2038706
Fig. 1. (a) Conventional passive suspension system. (b) Electromagnetic suspension system.
ciency is reached when completely incorporated in the wheel
, . However, as a result, the unsprung mass of the vehicle increases, which is a disadvantage with regard to passenger
comfort and handling. These trends clearly show the need
of active suspension to be incorporated into vehicles. These systems allow for greater suspension articulation when driving under low-yaw circumstances (driving relatively straight) to absorb road irregularities and have a much more rigid response when the car is driven through turns, which improves vehicle dynamics. To facilitate the ideal suspension with regard to
comfort, handling, and safety, various commercial technologies are used to improve or replace the conventional passive suspension system shown in...
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