| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electrically-driven braking device that can accurately determine a reference position as a position where a friction member (for example, a brake pad) begins to come into contact with a rotary member (for example, a brake disk).SOLUTION: When a braking manipulated variable is decreased, a rigidity value (Gcq) as the ratio of the amount (Fbh) of change in actual pressing force (Fba) of a friction member to the amount (Mkh) of change in actual position (Mka) of an electric motor is computed in sequence. Once the rigidity value changes from a predetermined value or larger to less than the predetermined value, the actual position at the point of time is stored as a candidate position (Mkk). The candidate position is discarded when a continuance of a state in which the rigidity value is less than the predetermined value is less than a gap equivalent value equivalent to a gap of a transmission member while the candidate position is stored. At the moment when the continuance of the state in which the rigidity value is less than the predetermined value exceeds the gap equivalent value, the stored candidate position is determined as a reference position (pzr) where the friction member and rotary member begin to come into contact with each other.</p> |
