Sughrue Mion, PLLC
Motor driving device and electric power steering apparatus
In a motor driving device where a motor having a winding wire with small inductance value is driven by a digital control means comprised of control means including a current command value calculating means, a current control means and a PWM control means whose sampling periods are different from each other, when discrete signals sampled by the respective control means are zero-order-held, a motor current includes a lot of higher harmonic waves due to a quantization error, thereby increasing a motor noise.When an n-th-order hold means is provided between the respective control means with different sampling periods, the quantization error can be reduced remarkably, and thus the higher harmonic wave components included in the motor current are reduced, thereby greatly reducing the motor noise.
NSK Steering Systems Co., Ltd. NSK Ltd.
B H
B62D H02P
inventional additional
Kenji Masahide Lilit Toru Shuji
Mori Saito Kovudhikulrungsri Sakaguchi Endo