Elektrisches Servolenk-Steuer- bzw. Regelsystem und Regelverfahren hierfür

摘要

An electric power steering control system is arranged so as to control a drive current of a brushless motor that generates a steering assist force on the basis of a steering torque acting on a steering shaft and a vehicle speed. The system comprises a d-q axis voltage command section for computing a d- and q-axis voltage command value in response to a deviation of current between a d- and q-axis current command value and a d- and q-axis detection current value, a d-q coordinate inverse transformation section for performing the d-q coordinate inverse transformation on the basis of the d- and q-axis voltage command value and an electrical angle signal, eventually thereby computing a three-phase voltage command value, a three-phase voltage command compensation section for performing compensation with respect to the three-phase voltage command value according to a computing expression for improving the efficiency of utilizing a preset voltage, thereby computing a three-phase voltage command compensation value, and a PWM output section for generating a PWM waveform for PWM drive of the brushless motor in response to the three-phase voltage command compensation value.