ELECTRIC POWER STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an electric power steering device enhancing stability of a vehicle relative to sudden variation of road surface reaction force without accompanying with reduction of steering feeling. SOLUTION: In a normal road surface reaction force calculation part 101, normal road surface reaction force TLref based on a steering angleθs of a steering wheel and a vehicle speed V is calculated, and at a road surface presumption part 103, a motor voltage Vm and actual road surface reaction force TLest based on a motor voltage Vm, a motor current Im or the like is calculated. It is determined at a comparison determination part 105 that a variation directions of the variation amountΔTLref and the variation amountΔTLest are same or mutually reverse and a magnitude relationship of the "ΔTLref" and the "ΔTLest" is determined. At an instruction correction value output part 107, based on the determination result, an instruction current correction valueΔImCrin an operation direction according to deviation of ä"ΔTLest"-"ΔTLref"} is outputted or the instruction current correction valueΔImCrin a returning direction according to deviation of "ΔTLref-ΔTLest" is outputted. COPYRIGHT: (C)2010,JPO&INPIT