US 12,434,765 B2
Rotation angle detection device for detecting steering angle of steering shaft of vehicle with wheels
Yoshitaka Nishiguchi, Nisshin (JP); Ken Tanaka, Kariya (JP); and Keisuke Uchida, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on May 10, 2023, as Appl. No. 18/314,920.
Application 18/314,920 is a continuation of application No. PCT/JP2021/038433, filed on Oct. 18, 2021.
Claims priority of application No. 2020-190049 (JP), filed on Nov. 16, 2020.
Prior Publication US 2023/0278629 A1, Sep. 7, 2023
Int. Cl. B62D 15/02 (2006.01); G01D 5/14 (2006.01)
CPC B62D 15/0215 (2013.01) [B62D 15/0235 (2013.01); G01D 5/145 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A rotation angle detection device for a vehicle with wheels, the rotation angle detection device comprising:
a first detection unit configured to detect a first rotation angle of a steering shaft that rotates with a steering wheel for operating a steering angle of the wheels;
a second detection unit configured to detect a second rotation angle of a motor shaft coupled to the steering shaft via a speed reduction mechanism; and
a calculation unit configured to:
receive the first rotation angle from the first detection, unit;
receive the second rotation angle from the second detection, unit; and
calculate, without using a self-aligning torque value, a steering angle of the steering shaft based on a difference angle between the first rotation angle and the second rotation angle, wherein:
the first detection unit includes:
a driving gear that rotates with the steering shaft;
a driven gear meshing with the driving gear to rotate with the driving gear;
a magnet fixed on the driven gear to rotate with the driven gear; and
a magnetic flux detector configured to detect the first rotation angle of the steering shaft based on a change in magnetic flux received from the magnet,
a first reduction ratio of the speed reduction mechanism between the steering shaft and the motor shaft is defined as ZEPS,
a second reduction ratio between the driving gear and the driven gear is defined as Zangle,
an angle range of the steering angle acquired by the calculation unit is defined as 0, and
the first reduction ratio, the second reduction ratio, and the angle range of the steering angle are combined and set to satisfy
|(ZEPS−Zangle)×θ|<360°
or
|(ZEPS−Zangle)×θ|<180°.