Patent ID: 6949901
Filing Date: 2005-09-27
Classification: B62D

Abstract:
1. A method for controlling a steering position of at least one rear wheel of a vehicle, the vehicle having both a brushless electric motor with a plurality of electrical phase windings and a steering actuator, the brushless electric motor having a rotor configured to drive the steering actuator, the steering actuator being operably coupled to at least one rear vehicle wheel, comprising: 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 of the brushless electric motor based on a desired rear vehicle wheel steering angle and a measured rear vehicle wheel steering angle; determining when the desired voltage value is greater than a threshold voltage level; calculating a phase advance angle based on at least the desired voltage value and the threshold voltage level; and phase advancing a plurality of voltage waveforms applied to the plurality of electrical phase windings, 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 moves at least one rear vehicle wheel toward the desired rear vehicle wheel steering angle.