Advics Co., Ltd.

Naotoshi Satake

Yoshiyuki Yasui

Hiroyuki Kodama

A vehicle brake control device includes an electric motor controlled based on a target energization amount calculated based on an operation amount (Bpa) of a braking operation member. Based on the operation amount (Bpa), it is determined whether or not an inertia compensation control for compensating for the influence of the inertia of a brake actuator is necessary. When the inertia compensation control is determined to be necessary, an inertia compensation energization amount for compensating for the influence of the inertia of the brake actuator is calculated based on a time-series pattern set in advance based on the maximum response of the brake actuator. Based on the inertia compensation energization amount, the target energization amount is calculated. The vehicle brake control device is thus able to generate a braking torque that appropriately compensates for the influence of the inertia of the entire device including the inertia of the electric motor.

Braking control device for vehicle

Based on a difference (&#x394;Fb) between a target value (Fbt) and an actual value (Fba) of a friction member force for pressing a brake disc, a feedback energization amount (Ipt) is calculated using a proportional gain smaller than an ultimate sensitivity gain. If &#x394;Fb falls within a fluctuation range of torque ripple, a first compensation energization amount (Ibt) is calculated using a proportional gain larger than the ultimate sensitivity gain, and if &#x394;Fb falls outside the fluctuation range, the first compensation energization amount (Ibt) is calculated to be constant. A second compensation energization amount (Ift) is calculated based on a calculation characteristic that is preset based on a torque fluctuation over a predetermined range of an electric motor position and based on an actual position of the electric motor. An indication energization amount calculated according to Fbt is adjusted by Ipt, Ibt, and Ift to calculate a target energization amount.

An electric motor is controlled based on a target energization amount calculated based on an operation amount of a braking operation member. Based on the operation amount, it is determined whether or not an inertia compensation control for compensating for the influence of the inertia of a brake actuator is necessary. When the inertia compensation control is determined to be necessary, an inertia compensation energization amount compensating for the influence of the inertia of the brake actuator is calculated using a time-series pattern set in advance based on the maximum response of the brake actuator. Using the inertia compensation energization amount, the target energization amount is calculated. The vehicle brake control device causes an electric motor to generate a braking torque and appropriately compensates for the influence of the inertia of the entire device including the inertia of the electric motor.

When a braking operation amount is reduced, a stiffness value representing a ratio of variation in actual pressing force of a friction member to a variation in actual position of an electric motor are sequentially computed. The actual position when the stiffness value changes from being higher than or equal to a predetermined value to being lower than the predetermined value is stored as a candidate position. When a duration during which the stiffness value is lower than the predetermined value is shorter than a clearance corresponding value corresponding to a transmission member clearance in a state where the candidate position is stored, the candidate position is deleted. When the duration during which the stiffness value is lower than the predetermined value exceeds the clearance corresponding value, the stored candidate position is determined as a reference position at which the friction member and the rotary member begin contacting each other.

Electric braking system for vehicle

Based on a difference between target and actual values of a friction member force pressing a brake disc, feedback control over the pressing force is executed. As the actual value, a 'limit pressing force (Fbs) obtained by placing a limitation on a temporal change amount of the Fba based on a limit value (Lmt)' is used. The limit value (Lmt) is set based on an electric motor speed (dMkt, dMka), a wheel speed (Vwa), and a temporal change amount (&#x394;Tmp) of the friction member temperature. The Lmt is set to increase as the dMkt (dMka) increases and the temporal change amount (&#x394;Tmp) of the temperature increases, and to also increase as the wheel speed (Vwa) decreases. Thus, even when a rotating member (brake disc) is deformed, braking torque control can be appropriately executed without accelerating a fluctuation of a braking torque on the wheel.

Braking control apparatus for vehicle

Electric motor control is based on a target energization amount calculated using a braking operation member operation amount. A state quantity is acquired as an actual value, indicating an actual actuation state of a movable member located in a power transmission path from the electric motor to a friction member. Using the operation amount, it is determined whether or not inertia compensation control is necessary, which compensates for the inertia influence of a brake actuator during electric motor deceleration. 'A target value corresponding to the actual value' is determined as a reference value, which is calculated based on the operation amount at a time when inertia compensation control is necessary. Based on the actual and reference values, 'an inertia compensation energization amount for decreasing the target energization amount to compensate for the influence of inertia' is calculated, and the target energization amount is adjusted using the inertia compensation energization amount.

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Nagoya, Japan

Naotoshi Satake