| 摘要 |
<p>A system and a method for controlling a steering position of at least one rear wheel (94) of a vehicle (10) are provided. The vehicle (10) has both a brushless electric motor (60) with a plurality of electrical phase windings (64, 66, 68) and a steering actuator (74). The brushless electric motor (60) has a rotor (62) configured to drive the steering actuator (74). The steering actuator (74) is operably coupled to at least one rear vehicle wheel (94). The method includes determining a desired voltage value indicative of about one-half of a peak-to-peak voltage to be applied to each of the plurality of electrical phase windings (64, 66, 68) of the brushless electric motor (60) based on a desired rear vehicle wheel steering angle and a measured rear vehicle wheel steering angle. The method further includes determining when the desired voltage value is greater than a threshold voltage level. The method further includes calculating a phase advance angle based on at least the desired voltage value and the threshold voltage level. The method further includes phase advancing a plurality of voltage waveforms applied to the plurality of electrical phase windings (64, 66, 68), wherein each phase advanced voltage waveform is phase advanced an amount substantially equal to the phase advance angle, wherein phase advancing the voltage waveforms increases a speed of the rotor at a desired torque to thereby increase a speed at which the steering actuator (74) moves at least one rear vehicle wheel (94) toward the desired rear vehicle wheel steering angle.</p> |
