A valve system includes an isolation check valve delivering pneumatic fluid as a supply pressure, a double-check valve adapted to deliver a braking demand control signal of the pneumatic fluid based on a higher of a first braking demand in a first pneumatic braking circuit and a second braking demand in a second pneumatic braking circuit, and a control module. The control module is adapted to receive the supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid based on the braking demand control signal, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal.

A valve arrangement for a trailer brake module in a monoblock housing includes an input for a brake supply pressure, an input for a brake control pressure, and an output for supplying a brake pressure to braking devices on a trailer. The valve arrangement includes a relay valve, and includes control solenoids which are arranged substantially transversely to the direction of motion of the relay valve piston.

A trailer brake system that generates load-dependent braking forces. Variable trailer load information is used to generate load-dependent control signals which serve to control an electrically-controlled proportional valve. A load sensing valve serves to modify brake command signals in dependence on a control pressure that is regulated by the proportional valve.

Brake lock detection is described for a brake activation system. In one example, a main housing is configured to engage an interior surface of a towed vehicle near a brake pedal of the towed vehicle. An actuation arm extends away from the main housing configured to connect to the brake pedal to actuate a brake of the towed vehicle through the brake pedal. An arm drive system of the main housing applies a positive pressure to the actuation arm when activated to drive the brake pedal to actuate the brake. A negative pressure sensor generates a negative pressure signal when the brake pedal applies a negative pressure opposite the positive pressure to the actuation arm and the actuation arm is not activated.

Brake lock detection is described for a brake activation system. In one example, a main housing is configured to engage an interior surface of a towed vehicle near a brake pedal of the towed vehicle. An actuation arm extends away from the main housing configured to connect to the brake pedal to actuate a brake of the towed vehicle through the brake pedal. An arm drive system of the main housing applies a positive pressure to the actuation arm when activated to drive the brake pedal to actuate the brake. A negative pressure sensor generates a negative pressure signal when the brake pedal applies a negative pressure opposite the positive pressure to the actuation arm and the actuation arm is not activated.

A valve system includes an isolation check valve delivering pneumatic fluid as a supply pressure, a double-check valve adapted to deliver a braking demand control signal of the pneumatic fluid based on a higher of a first braking demand in a first pneumatic braking circuit and a second braking demand in a second pneumatic braking circuit, and a control module. The control module is adapted to receive the supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid based on the braking demand control signal, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal.

A valve system includes a control module on a tractor portion of a vehicle adapted to receive a supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal. A supply glad-hand fluidly communicates the selectively transmitted supply pressure of the pneumatic fluid to supply a brake on an associated trailer portion of the vehicle. A control glad-hand fluidly communicates the control module delivery pressure of the pneumatic fluid to control the brake on the associated trailer portion of the vehicle. An exhaust valve, which fluidly communicates with both the selectively transmitted supply pressure and the control module delivery pressure, exhausts the control module delivery pressure of the pneumatic fluid from the control glad-hand.

The invention relates to a driverless transport vehicle for moving a semi-trailer. The driverless transport vehicle comprises a coupling device which is designed to establish a connection with the braking system and/or an electronic system of a semi-trailer. The invention also relates to a method for coupling a driverless transport vehicle to a semi-trailer.

An electronic brake system for a trailer with a pneumatic brake installation is disclosed. The electronic brake system comprises a brake controller (18) in the trailer (11) connected to a first communication device (20) that is part of a first communication channel (23) for wirelessly receiving brake signals of a towing vehicle (10). The electronic brake system also comprises a second communication channel for receiving brake signals of the towing vehicle. The brake controller (18) converts the brake signals of the first communication channel (23) into brake commands for the pneumatic brake installation only if brake signals arrive via the second communication channel (24) at the same time or within a defined time window. The time window begins as soon as a brake signal arrives on one of the first and second communication channels (23, 24).

Disclosed is a valve arrangement for aerating spring accumulator brake cylinders in a trailer vehicle with a pneumatic braking system, the valve arrangement having a first connection for a line connected to a reservoir of the trailer vehicle, a second connection for a line leading to the spring accumulator brake cylinders, and a first pneumatic control input, wherein the first connection can be connected to the second connection depending on the pressure on the first pneumatic control input. The first control input is connected to a line connected to a control connection of the trailer vehicle or to a line connected to the reservoir. A valve unit, a pneumatic braking system, a method of operating the same, and a trailer vehicle including the same are also disclosed.