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US 6,856,869 B2Granted
Electric power steering device
AssigneeToyoda Koki Kabushiki Kaisha
InventorToshihiro Takahashi
Life of this patent
Estimating the term…
Abstract
An electric power steering device which includes a sample reliability level calculation device for calculating a reliability y of a sampling value θa as a neutral angle θc based on a vehicle speed V, a angular velocity ω, a steering torque T, and relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T when a sampling condition is established. The neutral angle estimation means temporarily determines, confirms, or renews the value of the neutral angle θc based on the sampling value θa and the reliability level y.
Claims16
An electric power steering device comprising:
- a neutral angle estimation means for estimating a neutral angle θc of a steering angle based on a sampling value θa of the steering angle when a predetermined sampling condition is established, the sampling condition being defined by a vehicle speed V, an angular velocity ω of the steering angle, a steering torque T, or relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T;
- and
- a sample reliability level calculation means for calculating a reliability y of the sampling value θa as the neutral angle θc based on the vehicle speed V, the angular velocity ω, the steering torque T, or the relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T when the sampling condition is established;
- wherein the neutral angle estimation means temporarily determines, confirms, or renews the value of the neutral angle θc based on the sampling value θa and the reliability level y.
1 more element
An electric power steering device comprising:
- a neutral angle estimation means for estimating a neutral angle θc of a steering angle based on a sampling value θa of the steering angle when a predetermined sampling condition is established, the sampling condition being defined by a vehicle speed V, an angular velocity ω of the steering angle, a steering torque T, or the relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T;
- a neutral angle reliability level calculation means for calculating a reliability level X of the neutral angle θc based on an absolute value of a difference between the neutral angle θc calculated by the neutral angle estimation means and the sampling value θa;
- and
- a control means for returning a steering wheel for determining a torque Tr for returning the steering wheel, for determining a calculation parameter for obtaining the torque Tr for returning the steering wheel, and for determining a calculation method for obtaining the torque Tr for returning the steering wheel.
1 more element
An electric power steering device comprising:
- a neutral angle estimation means for estimating a neutral angle θc of a steering angle based on a sampling value θa of the steering angle when a predetermined sampling condition is established, the sampling condition being defined by a vehicle speed V, an angular velocity ωof the steering angle, a steering torque T, or relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T;
- and
- a sample reliability level calculation means for calculating a reliability y of the sampling value θa as the neutral angle θc based on the vehicle speed V, the angular velocity ω, the steering torque T, or the relating values of the vehicle speed V, the angular velocity ω of the steering angle, and the steering torque T when the sampling condition is established, wherein the reliability level y is calculated based on at least one of the vehicle speed and a boundary value of the vehicle speed, a boundary value of a torque and an absolute value of the torque, a boundary value of the angular velocity and an absolute value of the angular velocity, an absolute value of a difference between a present steering torque and last steering torque and a predetermined threshold value of the difference between the present steering torque and said last steering torque;
- wherein the neutral angle estimation means temporarily determines, confirms, or renews the value of the neutral angle θc based on the sampling value θa and the reliability level y.
1 more element
Dependencies are inferred from the claim text.