Toyota Jidosha Kabushiki Kaisha

Hiroki Mima

Yasuhiro Tajima

Akihiro Takahashi

An electric-brake controller controls an electric brake operable by an electric motor. The electric-brake controller includes: a rotation-angle obtainer including (i) a relative-rotation-angle obtaining unit that obtains a relative rotation angle of the electric motor for a set time, based on values output and received from a rotation-angle sensor at intervals of the set time, and (ii) an absolute-rotation-angle obtaining unit that calculates the obtained relative rotation angle with consideration of an orientation of the relative rotation angle to obtain an absolute rotation angle that is a rotation angle of the electric motor from a start of its operation; a recognition-error detector that detects a recognition error in the rotation-angle obtainer based on the obtained absolute rotation angle or a changing state of the absolute rotation angle; and a motor controller that controls the electric motor based on a result of detection performed by the recognition-error detector.

Recognition-error detector and electric-brake controller

A solenoid is determined abnormal if a current flowing therethrough at a certain duty ratio falls within an abnormal range. After the abnormal determination, a first duty ratio is used to cause a current to flow through the solenoid at such a current value within a first range as to not drive the solenoid valve. The solenoid is determined provisionally normal if the current at the first duty ratio falls within the first range. After the provisionally normal determination, a second duty ratio is used to cause a current to flow through the solenoid at such a current value within a second range including a current value range greater than the first range as to drive the solenoid valve. The solenoid is determined normal if the current at the second duty ratio falls within the second range.

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Hiroki Mima