US 8,897,965 B2Granted

Electric power steering apparatus

AssigneeJtekt Corporation

InventorsTerutaka Tamaizumi, Hirozumi Eki, Masayuki Kita, Isao Namikawa

Life of this patent

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Abstract

An assisting command value calculating unit calculates a first assisting factor on the basis of the value of a torque differential control volume added to a basic assist control volume based on a steering torque value, while increasing or decreasing, on the basis of an assisting gradient, the torque differential control volume based on a torque differential value. The pinion angle F/B control unit calculates a pinion angle command value, capable of being converted to a steering angle of the steering wheel, on the basis of the steering torque and the first assisting factor, and executes rotational angle feedback control. The assisting command value calculating unit calculates an assisting command value on the basis of the value of a second assisting factor, calculated by the pinion angle F/B control unit, added to the first assisting factor.

Claims15

Dependent claims

An electric power steering apparatus comprising a steering force assisting device and a control unit, wherein

the steering force assisting device comprises a motor as a drive source and applies assist force to a steering system,
the control unit sets a basic component of the assist force based on steering torque transmitted to a steering shaft,
the control unit increases/decreases a compensation component based on a change rate of the basic component relative to a change in the steering torque, and calculates a first assist component based on a value obtained by adding the compensation component to the basic component,
the control unit calculates a rotation angle instruction value of a rotation shaft that can be converted into a turning angle of a turning wheel based on the steering torque and the first assist component,
the control unit executes a rotation angle feedback control based on the rotation angle instruction value to calculate a second assist component, and
the control unit controls an actuation of the steering force assisting device based on an assist instruction value that is on a basis of a value obtained by adding the second assist component to the first assist component.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/982,119Filed 28 Mar 2012
Priority: JP 2011-07299429 Mar 2011
Published: US 2013/0311044 A121 Nov 2013
Granted: 25 Nov 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B62D 5/0472
Controlling the motor: for damping vibrations
B62D 5/0463
Controlling the motor: calculating assisting torque from the motor based on driver input
B62D 6/08
Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits: responsive…
B62D
Motor vehicles