▁expensive ▁and ▁not ▁reprodu cible , ▁H IL ▁sim ul ators ▁allow ▁developers ▁to ▁validate ▁new ▁hardware ▁and ▁software ▁autom ot ive ▁solutions , ▁respect ing ▁quality ▁requirements ▁and ▁time - to - market ▁restrictions . ▁In ▁a ▁typical ▁H IL ▁Sim ulator , ▁a ▁dedicated ▁real - time ▁processor ▁executes ▁mathematical ▁models ▁which ▁em ulate ▁engine ▁dynamics . ▁In ▁addition , ▁an ▁I / O ▁unit ▁allows ▁the ▁connection ▁of ▁vehicle ▁sens ors ▁and ▁actu ators ▁( which ▁usually ▁present ▁high ▁degree ▁of ▁non - linear ity ). ▁Finally , ▁the ▁Electron ic ▁Control ▁Unit ▁( EC U ) ▁under ▁test ▁is ▁connected ▁to ▁the ▁system ▁and ▁stim ulated ▁by ▁a ▁set ▁of ▁vehicle ▁man eu vers ▁executed ▁by ▁the ▁sim ulator . ▁At ▁this ▁point , ▁H IL ▁simulation ▁also ▁offers ▁a ▁high ▁degree ▁of ▁repeat ability ▁during ▁testing ▁phase . ▁ ▁In ▁the ▁literature , ▁several ▁H IL ▁specific ▁applications ▁are ▁reported ▁and ▁simplified ▁H IL ▁sim ul ators ▁were ▁built ▁according ▁to ▁some ▁specific ▁purpose . ▁When ▁testing ▁a ▁new ▁EC U ▁software ▁release ▁for ▁example , ▁experiments ▁can ▁be ▁performed ▁in ▁open ▁loop ▁and ▁therefore ▁several ▁engine ▁dynamic ▁models ▁are ▁no ▁longer ▁required . ▁The ▁strategy ▁is ▁restricted ▁to ▁the ▁analysis ▁of ▁EC U ▁outputs ▁when ▁excited ▁by ▁controlled ▁inputs . ▁In ▁this ▁case , ▁a ▁Micro ▁H IL ▁system ▁( M H IL ) ▁offers ▁a ▁simpler ▁and ▁more ▁economic ▁solution . ▁Since ▁complexity ▁of ▁models ▁processing ▁is ▁dump ed , ▁a ▁full - size ▁H IL