A brake pressure modulator (1) of an electronic braking system of a utility vehicle includes pressure control circuits (13, 14) respectively associated with a braking circuit of a vehicle axle, each pressure control circuit (13, 14) comprises a compressed air supply system (4, 5), at least one redundancy control pressure path (21), at least one ventilation path (19, 19a) and a common electronic control unit (2). Said pressure control circuits (13, 14) can be controlled independently from each other by the electronic control unit (2). Each pressure control circuit (13, 14) has an independent ventilation path (19, 19a) and at least one of the pressure control circuits (13, 14) has an independent redundancy control pressure path (21) and at least one other of the pressure control circuits (13, 14) comprises a device (16a) for forced venting in the event of a failure by means of the associated ventilation path (19a).

Brake fluid inside a first wheel cylinder is pressurized by using a first pressure-regulating mechanism and brake fluid inside a second wheel cylinder is pressurized by using a second pressure-regulating mechanism. If a determination means determines that the first pressure-regulating mechanism action is in an unsuitable state and the second pressure-regulating mechanism action is in a suitable state, the control means pressurizes the brake fluid inside the first wheel cylinder by using a master cylinder and pressurizes the brake fluid inside the second wheel cylinder by using the second pressure-regulating mechanism, when an operation volume is less than a value. When the operation volume has reached the value, the control means pressurizes the brake fluid inside the first and second wheel cylinders by using the second pressure-regulating mechanism.

An electronically controllable pneumatic brake system for a utility vehicle has an electronic service brake control unit and a brake pressure modulator which modulates a service brake pressure at a service brake pressure port in accordance with service braking signals provided by the electronic service brake control unit. The brake pressure modulator has a ventilation port. The brake system furthermore has an electronic redundancy control unit and at least one redundancy pressure modulator which modulates a redundancy brake pressure at a redundancy brake pressure port in accordance with redundancy braking signals that are provided by the electronic redundancy control unit. The redundancy pressure modulator has a redundancy ventilation port. Provision is made for the redundancy brake pressure port to be connected to the ventilation port such that the redundancy brake pressure can be modulated, via a ventilation path of the brake pressure modulator, at the service brake pressure port.

A method for determining an operating variable of a drum brake comprises actuating the brake in at least one of: a first wheel speed range and a second wheel speed range. The operating variable is calculated based on bearing force of a leading brake shoe and the further bearing force of a trailing brake shoe when in the first wheel speed range. The operating variable is calculated when in the second wheel speed range based on a current actuator position and an actuator contact position, in which brake shoes of the drum brake come into engagement with a drum of the drum brake.

A brake system includes a first electric power-supply-unit (EPSU) and a first electronic-brake-control-unit (EBCU). The first EBCU is connected to the first EPSU. Also, the brake system includes a second EPSU and a second EBCU, which is connected to the second EPSU. The brake system further includes a first axle-pressure-modulator (APM) for service-brake-chambers associated with a first vehicle-axle. The brake system includes a second APM for spring-brake-cylinders for a second vehicle-axle. The brake system includes two power-supply-switches (PSS). A first PSS is connected to the first EBCU, the second EBCU and the first APM and configured to connect the first EBCU or the second EBCU to the first APM. A second PSS is connected to the first EBCU, the second EBCU and the second APM and configured to connect the first EBCU or the second EBCU to the second APM.

A brake system includes a first electric power-supply-unit (EPSU) and a first electronic-brake-control-unit (EBCU). The first EBCU is connected to the first EPSU. Also, the brake system includes a second EPSU and a second EBCU, which is connected to the second EPSU. The brake system further includes a first axle-pressure-modulator (APM) for service-brake-chambers associated with a first vehicle-axle. The brake system includes a second APM for spring-brake-cylinders for a second vehicle-axle. The brake system includes two power-supply-switches (PSS). A first PSS is connected to the first EBCU, the second EBCU and the first APM and configured to connect the first EBCU or the second EBCU to the first APM. A second PSS is connected to the first EBCU, the second EBCU and the second APM and configured to connect the first EBCU or the second EBCU to the second APM.

A brake system for a transportation vehicle and a transportation vehicle having such a brake system. The brake system includes two brake circuits which each have a control unit and a battery, wherein the respective control unit actuates two of a total of four service brakes and at least one of at least two electric parking brakes. The brake system also has an electronic circuit element. The brake system forms a defect signal in response to a double fault affecting the two brake circuits and when a defect in at least one of the control units is detected, and/or in which a respective supply voltage of at least one of the control units drops below a predefined limiting value. The at least one electronic circuit element actuates the electric parking brakes when a defect signal is formed.

A redundancy valve assembly is for redundantly supplying a redundant brake pressure into a service brake pressure path of an electronically controllable pneumatic brake system for a vehicle, preferably a utility vehicle, including a service brake pressure connection for receiving a service brake pressure from a service brake pressure modulator, a redundancy brake pressure connection for receiving a redundancy brake pressure from a redundancy brake pressure modulator, and a brake actuator connection for connecting at least one brake actuator. The redundancy valve assembly is electrically actuatable in order to optionally modulate the service brake pressure or the redundancy brake pressure at the brake actuator connection. An electronically controllable pneumatic brake system includes a redundancy control unit. A vehicle includes the electronically controllable pneumatic brake system. A method is for controlling an electronically controllable pneumatic brake system.

A device for a hydraulic actuating system, e.g., a motor vehicle brake, a clutch or a gear selector, may include the following components arranged in one housing, forming a main module: at least one pressure supply device driven by an electric motor drive, and a valve arrangement comprising at least one solenoid valve. The device may further include an electrical control unit (ECU) and valve output stages and sensors. The main module may be electrically and/or hydraulically connected to at least one further system component, which system component may include and actuating device and a travel simulator.

An electric brake system includes a plurality of electric brake devices. A control device of each electric brake device includes: an abnormality determination section that determines whether there is abnormality in supply of power from a power supply device to the electric brake device; and a redundant function control section that, when the abnormality determination section has determined that there is abnormality in supply of power, controls the braking force by using an auxiliary power supply in accordance with a predetermined condition. The redundant function control section controls the braking force by using the auxiliary power supply at least when a desired braking force cannot be output even with all the electric brake devices for which the abnormality determination section has determined that there is no abnormality in supply of power, as the predetermined condition.