Systems and methods for a braking a vehicle. In one example, the braking system includes a friction braking system, a regenerative braking system, and an electronic processor. The electronic processor is communicatively coupled to the friction braking system and the regenerative braking system. The electronic processor is configured to receive a driver brake request and determine a brake failure state. The brake failure state indicates a brake failure. In response to determining the brake failure state, the electronic processor applies a braking force based on the driver brake request. The braking force includes a frictional braking force generated by the friction braking system and a regenerative braking force generated by the regenerative braking system.

A method and system for determining the pressure in a brake booster used to actuate a brake system having at least one main brake cylinder. The brake booster connected in a fluid-conducting manner by a non-return valve to an intake manifold of an internal combustion engine. A reduced pressure loss in the brake booster resulting from actuation of the main brake cylinder is balanced with the reduced pressure gain in the brake booster as a result of a pressure difference between the brake booster pressure and the intake manifold pressure. The reduced pressure gain in the brake booster is determined based on time, the air mass flow between the brake booster, and the intake manifold.

A method and system for determining the pressure in a brake booster used to actuate a brake system having at least one main brake cylinder. The brake booster connected in a fluid-conducting manner by a non-return valve to an intake manifold of an internal combustion engine. A reduced pressure loss in the brake booster resulting from actuation of the main brake cylinder is balanced with the reduced pressure gain in the brake booster as a result of a pressure difference between the brake booster pressure and the intake manifold pressure. The reduced pressure gain in the brake booster is determined based on time, the air mass flow between the brake booster, and the intake manifold.

Venturi devices are disclosed herein that include a body defining a Venturi gap between an outlet end of a converging motive section and an inlet end of a diverging discharge section, having a suction port in fluid communication with the Venturi gap, a gate valve linearly translatable to open and close the Venturi gap, and an actuator connected to the gate valve to operatively move the gate valve between an open position and a closed position. The gate valve, in a longitudinal cross-section, is generally U-shaped, thereby having continuous, opposing sides that one each close the motive outlet and the discharge inlet and defining a void between the opposing sides that is in fluid communication with the suction port. The converging motive section defines a circular-shaped motive inlet and defines an elliptical- or polygonal-shaped motive outlet, and the diverging discharge section defines an elliptical- or polygonal-shaped discharge inlet.

Venturi devices are disclosed herein that include a body defining a Venturi gap between an outlet end of a converging motive section and an inlet end of a diverging discharge section, having a suction port in fluid communication with the Venturi gap, a gate valve linearly translatable to open and close the Venturi gap, and an actuator connected to the gate valve to operatively move the gate valve between an open position and a closed position. The gate valve, in a longitudinal cross-section, is generally U-shaped, thereby having continuous, opposing sides that one each close the motive outlet and the discharge inlet and defining a void between the opposing sides that is in fluid communication with the suction port. The converging motive section defines a circular-shaped motive inlet and defines an elliptical- or polygonal-shaped motive outlet, and the diverging discharge section defines an elliptical- or polygonal-shaped discharge inlet.

Methods and systems are provided for controlling air flow through at least two aspirators coupled across an intake throttle. In one example, a method includes, during a first condition, opening a common aspirator shut-off valve to direct intake air through a first aspirator and a second aspirator each coupled across an intake throttle, and supplying vacuum generated by the first aspirator and the second aspirator to respective vacuum consumption devices as demanded. The method also includes, responsive to a second condition, closing the common aspirator shut-off valve and supplying intake manifold vacuum to the respective vacuum consumption devices as demanded.

Methods and systems are provided for controlling air flow through at least two aspirators coupled across an intake throttle. In one example, a method includes, during a first condition, opening a common aspirator shut-off valve to direct intake air through a first aspirator and a second aspirator each coupled across an intake throttle, and supplying vacuum generated by the first aspirator and the second aspirator to respective vacuum consumption devices as demanded. The method also includes, responsive to a second condition, closing the common aspirator shut-off valve and supplying intake manifold vacuum to the respective vacuum consumption devices as demanded.

A control device for an electric vacuum pump that generates a negative pressure includes a negative-pressure detector for detecting the negative pressure generated by the electric vacuum pump and a pump stop control unit that is adapted to stop the electric vacuum pump when the negative pressure detected by the negative-pressure detector is not less than a predetermined value. The pump stop control unit is configured to determine an OFF timing at a present stage of the electric vacuum pump based on reference pump-filling-performance data, which is data about a reference negative pressure ratio relative to an elapsed time at an initial stage of the electric vacuum pump, and by referring to present pump-filling-performance data, which is data about a present negative pressure ratio relative to an elapsed time at the present stage of the electric vacuum pump.

A method and a system for verifying normal operation of a negative pressure sensor of a brake booster is provided. The method and system verify whether the negative pressure sensor of the brake booster is in normal operation and the normal operation of the booster negative pressure sensor is detected by mutually verifying values measured by the booster negative pressure sensor and values measured by sensors that indirectly sense the booster negative pressure.

A method and a system for verifying normal operation of a negative pressure sensor of a brake booster is provided. The method and system verify whether the negative pressure sensor of the brake booster is in normal operation and the normal operation of the booster negative pressure sensor is detected by mutually verifying values measured by the booster negative pressure sensor and values measured by sensors that indirectly sense the booster negative pressure.