ROAD LOAD INSENSITIVE ELECTRIC POWER STEERING SYSTEM

摘要

ROAD LOAD INSENSITIVE ELECTRIC POWER STEERING SYSTEM The torque gain of an electric motor assisted power steering system is modified as a function of the estimated level of road load friction such that the relationship between the operator exerted steering torque and the resulting rate of steer is substantially insensitive to a reduction in the level of road load. The road load is estimated as a function of the operator exerted steering torque, the torque assist provided by the electric motor, and the resulting steer rate.