Energy saving for electromagnetic clutch in electric power steering system

Electric Power Steering(EPS) system is not a real on-demand steering system. An energy sa-ving strategy was provided through the analysis of its working. Using the Pulse-Width Modulation (PWM), the electromagnetic clutch current is controlled according to the assistance current of EPS motor. Two evaluation methods of the energy saving effect were presented under certain steering situation and a real roadtest, respectively. Based on the actual steering performance, three typical steering situations: extremely parking steering, wide range angle steering and on-center steering, and a typical section of a highway were selected. Bench test results showed that the introduced strategy reduced energy expenditure.