Patent ID: 7154244

Claim:
A steering apparatus of a motor vehicle having a pair of steerable wheels that are manually steerable by a driver, comprising: first and second motors each generating a steering assisting force to be applied to a manual steering system of the motor vehicle that is connected to the steerable wheels to assist the driver's manual steering effort in steering the steerable wheels; first and second drive circuits for PWM-controlling said first and second motors, respectively, each of said first and second drive circuits including a switching element switched on and off at a control frequency; and a control system connected to the first and second drive circuits and producing a first control signal at a first control frequency at which said switching element of the first drive circuit is switched on and off and a second control signal at a second control frequency at which said switching element of said second drive circuit is switched on and off, wherein the first control frequency has a value that is greater than the second control frequency.