CONTROL STRATEGY FOR A MOTOR OF AN ELECTRIC ASSISTED STEERING SYSTEM

摘要

A control strategy for an electric motor of an electric power assisted steering system of the kind in which a control means produces motor current demand signals that are fed to a motor drive means, the demand signals being dependent on the amount of assistance torque demanded from the motor, the motor drive means being arranged to cause currents to flow in each phase of the motor as required to meet the demanded assistance torque, the control strategy comprising limiting the rate of change of current that is drawn from the electrical supply of the vehicle by the motor in the event that it would otherwise exceed a threshold rate of change.