A brake system includes a master cylinder configured to generate a hydraulic pressure, a primary brake actuator configured to increase and decrease the hydraulic pressure generated in the master cylinder, a secondary brake actuator connected in series with and downstream of the master cylinder and in series with and upstream of the primary brake actuator, and configured to increase and decrease the hydraulic pressure generated in the master cylinder, and at least one wheel cylinder configured to apply brake torque to a wheel of a vehicle based on the hydraulic pressure generated by the master cylinder and increased or decreased by the primary actuator or the secondary actuator. An automatic brake hold control method includes sequential performing an automatic brake hold control on at least one wheel cylinder by the primary brake actuator and then the secondary brake actuator.

A controller and a control method to a vehicle, the controller and the control method executing brake control in which primary information is selectively supplemented by secondary information that is information on an assumed state related to connection and disconnection of a clutch. The controller includes a determination section that determines whether an actual state and the assumed state, which are related to the connection and the disconnection of the clutch, match each other in accordance with a temporal change in the secondary information; and a brake control section that executes the brake control by using the primary information but not the secondary information in the case where the determination section determines that the actual state and the assumed state do not match each other.

Systems and methods for controlling a vehicle. One example system includes a deceleration actuator coupled to a first wheel of the vehicle and an electronic processor communicatively coupled to the deceleration actuator. The electronic processor is configured to receive a vehicle park command. The electronic processor is configured to, responsive to receiving the vehicle park command, determine a maximum holding pressure threshold. The electronic processor is configured to determine a requested braking pressure for the deceleration actuator. The electronic processor is configured to determine whether the requested braking pressure exceeds the maximum holding pressure threshold. The electronic processor is configured to, responsive to determining that the requested braking pressure does not exceed the maximum holding pressure threshold, control the deceleration actuator to apply, to the first wheel during a hold time, a holding braking pressure equivalent to the requested braking pressure.

The invention has a purpose of improving applicability of a controller and a control method to a vehicle, the controller and the control method executing brake control in which primary information is selectively supplemented by secondary information that is information on an assumed state related to connection and disconnection of a clutch.

The invention includes: a determination section 5A1 that determines whether an actual state and the assumed state, which are related to the connection and the disconnection of the clutch, match each other in accordance with a temporal change in the secondary information; and a brake control section 5A4 that executes the brake control by using the primary information but not the secondary information in the case where the determination section 5A1 determines that the actual state and the assumed state do not match each other.

A power split hybrid powertrain includes an electrically actuated brake that selectively engages a ring gear attached to a flywheel. The ring gear may be, for example, a starter ring gear. Engagement of the brake while the engine is stopped permits use of both electric machines to provide torque to vehicle wheels, thereby increasing the electric torque capacity of the powertrain. The brake is mounted for movement relative to the ring gear, and a mechanical linkage is attached to the brake. In the event of a malfunction of the brake that prevents normal operation of the powertrain, the linkage is manually actuatable by a vehicle operator to move the brake to an override position wherein it cannot engage the ring gear.

A power split hybrid powertrain includes an electrically actuated brake that selectively engages a ring gear attached to a flywheel. The ring gear may be, for example, a starter ring gear. Engagement of the brake while the engine is stopped permits use of both electric machines to provide torque to vehicle wheels, thereby increasing the electric torque capacity of the powertrain. The brake is mounted for movement relative to the ring gear, and a mechanical linkage is attached to the brake. In the event of a malfunction of the brake that prevents normal operation of the powertrain, the linkage is manually actuatable by a vehicle operator to move the brake to an override position wherein it cannot engage the ring gear.

The present invention provides a parking brake actuator comprising: a motor; a worm gear connected to the motor so that power may be transmitted therebetween; a worm wheel engaged with the worm gear; a driving shaft coupled to the worm wheel and to which a parking cable is connected; and a power transmission gear including a first gear coupled to a rotary shaft of the motor, and a second gear coupled to the rotary shaft of the worm gear and connected to the first gear so that the power may be transmitted therebetween, wherein a gear ratio between the first gear and the second gear is 10:66 and a gear ratio between the worm gear and the worm wheel is 1:54.

The present relates to a method for operating a vehicle brake system which comprises a vehicle brake having a brake piston, an electrohydraulic service brake device, and an electromotive parking brake device having a spindle drive driven by an electric motor, wherein the electrohydraulic service brake device and/or the electromotive parking brake device act on the brake piston. The method determines an additional brake fluid volume to be delivered by the electrohydraulic service brake device in order to ensure a target clamping force (Fz-Soll) for a brake pad of the parking brake on application of the parking brake device.

The present invention provides a parking brake actuator comprising: a motor; a worm gear connected to the motor so that power may be transmitted therebetween; a worm wheel engaged with the worm gear; a driving shaft coupled to the worm wheel and to which a parking cable is connected; and a power transmission gear including a first gear coupled to a rotary shaft of the motor, and a second gear coupled to the rotary shaft of the worm gear and connected to the first gear so that the power may be transmitted therebetween, wherein a gear ratio between the first gear and the second gear is 10:66 and a gear ratio between the worm gear and the worm wheel is 1:54.

A brake system includes a master cylinder configured to generate a hydraulic pressure, a primary brake actuator configured to increase and decrease the hydraulic pressure generated in the master cylinder, a secondary brake actuator connected in series with and downstream of the master cylinder and in series with and upstream of the primary brake actuator, and configured to increase and decrease the hydraulic pressure generated in the master cylinder, and at least one wheel cylinder configured to apply brake torque to a wheel of a vehicle based on the hydraulic pressure generated by the master cylinder and increased or decreased by the primary actuator or the secondary actuator. An automatic brake hold control method includes sequential performing an automatic brake hold control on at least one wheel cylinder by the primary brake actuator and then the secondary brake actuator.