A brake booster for a brake system of a vehicle, having a first input piston component, and a valve body. The brake booster has a second input piston component, which is pushed away from the first input piston component in the braking direction using a compression spring, and a locking mechanism is embodied such that when the differential travel between the booster travel and the input travel is smaller than a predefined first limit value, the second input piston component is adjustable using the compression spring together with the valve body away from the first input piston component, and when the differential travel exceeds the first limit differential travel, the second input piston component is locked in place on the first input piston component.

A brake booster for a brake system of a vehicle, having a first input piston component, and a valve body. The brake booster has a second input piston component, which is pushed away from the first input piston component in the braking direction using a compression spring, and a locking mechanism is embodied such that when the differential travel between the booster travel and the input travel is smaller than a predefined first limit value, the second input piston component is adjustable using the compression spring together with the valve body away from the first input piston component, and when the differential travel exceeds the first limit differential travel, the second input piston component is locked in place on the first input piston component.

A master brake cylinder includes a unique mounting arrangement for securing thereof to a firewall of a vehicle and a particular porting arrangement. A cylinder sleeve includes a series of ports that cooperate with movement of the piston allowing for by-passing of the piston at one end position and then movement of the piston past the ports for brake actuation. Additionally a two stage pressure intensifier is provided that is in-line between a master brake cylinder and brake pistons. The intensifier also includes a by-pass position at one end of the movable piston having a differential area between a forward and a rear face of the piston.

A brake operation sensor detects a position of an input member. An angle sensor detects a position of a power piston. An ECU drives and controls an electric motor based on a relative position between the input member and the power piston. Then, the input member and the power piston are subjected to a mechanical limitation on a relative displacement therebetween due to abutment with each other at a step. The ECU advances/retracts the power piston independently of the movement of the input member, and determines the abutment state between the input member and the power piston under the mechanical limitation based on the detected relative position. Then, the ECU corrects the relative position between the input member and the power piston based on this determination to control the electric motor.

A brake operation sensor detects a position of an input member. An angle sensor detects a position of a power piston. An ECU drives and controls an electric motor based on a relative position between the input member and the power piston. Then, the input member and the power piston are subjected to a mechanical limitation on a relative displacement therebetween due to abutment with each other at a step. The ECU advances/retracts the power piston independently of the movement of the input member, and determines the abutment state between the input member and the power piston under the mechanical limitation based on the detected relative position. Then, the ECU corrects the relative position between the input member and the power piston based on this determination to control the electric motor.

A threaded nut of a ball-screw for a brake booster is constructed as a hydraulic piston and is produced from the group of martensitically hardening steels which are non-corroding with respect to brake fluid and which has in percent by weight: between 0.4% and 1.3% carbon (C), up to 2% silicon (Si), up to 2% manganese (Mn), between 12% and 20% chromium (Cr), and phosphorus (P) and sulphur (S) together at less than 0.015%, the balance being iron and, where applicable, melting-related impurities. Addition of the following materials to the above-described steel may be advantageous: up to 2% molybdenum (Mo), up to 0.2% vanadium (V), and up to 3% nickel (Ni).

A threaded nut of a ball-screw for a brake booster is constructed as a hydraulic piston and is produced from the group of martensitically hardening steels which are non-corroding with respect to brake fluid and which has in percent by weight: between 0.4% and 1.3% carbon (C), up to 2% silicon (Si), up to 2% manganese (Mn), between 12% and 20% chromium (Cr), and phosphorus (P) and sulphur (S) together at less than 0.015%, the balance being iron and, where applicable, melting-related impurities. Addition of the following materials to the above-described steel may be advantageous: up to 2% molybdenum (Mo), up to 0.2% vanadium (V), and up to 3% nickel (Ni).

A host vehicle includes a driver re-engagement assessment system and an X-by-wire device adapted for both manual control and automated control by an automated guidance system. The driver re-engagement assessment system includes a controller, a user interface, and test execution module and a test evaluation module. The user interface is configured to interface with an occupant and output an occupant directive signal for manual control to the controller. The test execution module initiates an occupant re-engagement test upon receipt of the occupant directive signal by the controller. The test evaluation module is configured to receive an occupant performance signal indicative of occupant performance during the re-engagement test, and evaluate the occupant performance signal to determine a test pass result and a test fail result. The manual control of the host vehicle is assumed by the occupant upon the determination of the test pass result.

A method for controlling a vehicle deceleration depending on a differential slip between two vehicle axles in a vehicle with an ABS brake system includes detecting at least one of a target vehicle deceleration specified by the driver and an actual vehicle deceleration; and controlling a braking pressure on wheel brakes of a vehicle axle to be controlled by actuation of ABS brake valves in such a way that the braking pressure on the wheel brakes of the vehicle axle to be controlled is controlled depending on a detected actual differential slip, so that the actual differential slip corresponds to a target differential slip. The actual differential slip indicates a difference in a rotational behavior of the vehicle axle to be controlled relative to a further vehicle axle. The target differential slip is dependent on at least one of the detected actual vehicle deceleration and the detected target vehicle deceleration.

A method for controlling a vehicle deceleration depending on a differential slip between two vehicle axles in a vehicle with an ABS brake system includes detecting at least one of a target vehicle deceleration specified by the driver and an actual vehicle deceleration; and controlling a braking pressure on wheel brakes of a vehicle axle to be controlled by actuation of ABS brake valves in such a way that the braking pressure on the wheel brakes of the vehicle axle to be controlled is controlled depending on a detected actual differential slip, so that the actual differential slip corresponds to a target differential slip. The actual differential slip indicates a difference in a rotational behavior of the vehicle axle to be controlled relative to a further vehicle axle. The target differential slip is dependent on at least one of the detected actual vehicle deceleration and the detected target vehicle deceleration.