Parking Behaviors for Inductive Charging

It is well established that the efficiency of transfer of electrical energy through induction is highly reliant on accurate alignment of the coils involved – in this case, between a primary coil in the parking bay and a secondary coil mounted on the vehicle. Whist inductive charging technology is market ready, understanding the issue of misalignment is an important human factors question and the focus of this paper. A retrospective assessment of parking behavior was conducted by recording parking orientation and alignment of 100 vehicles, parked in perpendicular bays, in three different car parks at the University of Warwick. Results showed on average vehicles tended to park 3.1 cm to the left of the bay, with an angle of practically zero. Parking was typically towards the rear of the bay; however the presence of a physical barrier led to vehicles being parked more centrally. The orientation of the parked vehicle had little impact on accuracy. Tolerances for misalignment with inductive charging systems are small in comparison to the distribution of parking accuracy observed in this study, at 15-20 cm verses 120 cm respectively. Conclusions were that only 5% of vehicles were parked sufficiently accurately to allow inductive power transfer to commence.