Page - 339 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 315 and the right side (Figure22b)are139.5degreesand−58.7degrees, respectively,whichmakes the phase difference between left and right side 198.2 degrees. This slightly exceeds the theoretical 180degreephasedifference, but thedifferencebetween the left regionandright regioncanstill be clearlydistinguished. (a) (b) Figure22.Oscilloscopereadings fromthesecondexperimentshowingthevoltagewaveformof the loadcoilandsensorcoilunitat (a) leftmisalignment;and(b) rightmisalignment. Thewaveforms (1) and (2) shown inFigure 23 show the converted squarewaveformsof the loadcoilandsensorcoiloutputs fromFigure22, respectively. Theseconvertedsquarewaveformsare fed into theXORgate,andtheoutputsignalsareshownaswaveform(3) inFigure23. Figure23a,b represent the leftmisalignmentcaseandtherightmisalignmentcase, respectively.Ascanbeseenfrom Figure21,aphasedifferencebetweenthe loadcoilandsensorcoil exists, thus theoutputgenerated by theXORgate isan“unclean”HIGHorLOWlogicoutput. However, it still verifies theconcept illustrated inFigure14. (a) (b) Figure23.Oscilloscopereadings fromthesecondexperimentshowingtheconverted logicwaveform of the (1) load coil; (2) sensor coil; and (3) the XOR gate output for (a) left misalignment; and (b) rightmisalignment. Tocompensate the“unclean”signal fromthe twosignals showninwaveform(3) inFigure21a,b, amovingaveragefilterwas implemented in themaincontrolleras follows: LPtotal= 1 N N−1 ∑ j=0 LP[i+ j] (11) where LPtotal is thefiltered lateral positionoutput basedon thenumber of samples,N. From this, theLPdescribed inEquation(10)canfinallybe identified,as follows: 339