US 7,520,365 B2
Steering apparatus for vehicle
Hitoshi Fukuba, Hiroshima-ken (Japan); Yoshihisa Okamoto, Hiroshima-ken (Japan); Naoki Yamada, Hiroshima-ken (Japan); Masaki Chiba, Hiroshima-ken (Japan); Yusuke Kohge, Hiroshima-ken (Japan); Hiroko Gendou, Hiroshima-ken (Japan); and Yusaku Takeda, Hiroshima-ken (Japan)
Assigned to Mazda Motor Corporation, Hiroshima (Japan)
Filed on Mar. 07, 2007, as Appl. No. 11/714,745.
Claims priority of application No. 2006-071557 (JP), filed on Mar. 15, 2006; application No. 2006-071558 (JP), filed on Mar. 15, 2006; application No. 2006-071559 (JP), filed on Mar. 15, 2006; application No. 2006-071560 (JP), filed on Mar. 15, 2006; and application No. 2006-071563 (JP), filed on Mar. 15, 2006.
Prior Publication US 2007/0219691 A1, Sep. 20, 2007
Int. Cl. B62D 6/00 (2006.01); A01B 69/00 (2006.01)
U.S. Cl. 180—402  [180/446; 701/42] 13 Claims
OG exemplary drawing
 
1. A steering apparatus for a vehicle, comprising:
a steering wheel;
a steering rod configured to give a steering angle of tires;
a steering motor coupled to the steering rod and configured to drive the steering rod to control the steering angle;
a steering reaction force generation motor coupled to the steering wheel and configured to give a steering feedback to a driver;
a torque sensor configured to detect a rotational torque on the steering wheel;
a steering angle sensor configured to detect a steering angle of the steering wheel; and
a control unit, said control unit comprising;
a generation unit configured to generate a drive signal as a measurement signal required to drive the steering feedback motor so as to forcibly turn the steering wheel a predetermined amount which does not substantially interfere with the driving of the vehicle; and
an estimation unit configured to estimate a mechanical impedance of the driver based on outputs from the torque sensor and the steering angle sensor when a steering manipulation is applied in response to the turn of the steering wheel by driving the steering reaction force generation motor according to the measurement signal;
wherein the control unit is configured to control the steering reaction force generation motor based on the estimated mechanical impedance, thereby giving a proper steering feedback to the driver.