Techniques for braking an autonomous vehicle include providing a pressurized fluid stream from a plurality of pressurized fluid sources to a plurality of pressure-controlled electronic braking assemblies; providing the pressurized fluid stream from a pressurized fluid control output of a first pressure-controlled electronic braking assembly directly to a pressurized fluid control input of a second pressure-controlled electronic braking assembly; providing the pressurized fluid stream from the second pressure-controlled electronic braking assembly to at least one vehicle brake set; providing sensor output data from one or more vehicle sensors to a plurality of electronic control units; and based at least in part on the sensor output data, controlling at least one of the first or second pressure-controlled electronic braking assemblies to adjust a pressure of the pressurized fluid stream from at least one of the first or second pressure-controlled electronic braking assemblies to the vehicle brake set.

Please substitute the new Abstract submitted herewith for the original Abstract: An electropneumatic parking brake control device controls a parking brake including at least one spring brake actuator. The control device includes a relay valve with a control chamber and a vent. The control chamber can be connected to the vent via at least one second throttle element and/or at least one third throttle element depending on the position of the relay piston.

A trailer control valve for a tractor includes a body defining a supply port and first and second delivery ports. The supply port is configured for fluid communication with a fluid source on the tractor. The first and second delivery ports are configured for fluid communication with glad-hand connectors through which fluid is supplied from the tractor to a trailer for, respectively, releasing a parking brake and applying a service brake. The first delivery port is in fluid communication with the supply port. A relay valve is supported within the body and includes a valve member configured to move between positions preventing and permitting fluid communication between the supply port and the second delivery port. Pressure transducers in the body generate pressure signals indicative of fluid pressure at the delivery ports permitting detection of the presence of a trailer coupled to the tractor.

A pneumatic braking device for a utility vehicle includes at least one pneumatically controllable spring accumulator for a parking brake of the utility vehicle with an electronic parking brake device. The electronic parking brake device has at least one electronic control unit, at least one first bistable valve unit, at least one second bistable valve unit, at least one valve device which can be connected in such a way that when there is a decrease in the system pressure for supplying the parking brake of the trailer of the traction vehicle, the parking brake of the trailer can be activated, and a traction vehicle protection valve.

A brake module for a hydraulically braked tractor coupled to a pneumatically braked trailer has a trailer control valve connected via hydraulic control inlet to a hydraulic pressure line leaving a master brake cylinder, and via pneumatic inlet to a compressed air reservoir. Hydraulic control pressure determines pneumatic output pressure level at a trailer control valve pneumatic outlet. The brake module has a break-off prevention module which, if the control line leaks or separates from the trailer control valve relative to the trailer brake system, closes a supply pressure coupling head supply line and causes trailer brake system venting. The break-off prevention module has a pneumatic supply pressure inlet and a pneumatic tear-off control pressure inlet connected to the air reservoir independently of trailer control valve pressure inlets. Supply pressure inlet supply pressure passes through the break-off prevention module and feeds to a trailer control valve pneumatic supply pressure inlet.

An electropneumatic parking brake module includes a supply port configured to connect a compressed air supply, a spring brake actuator port configured to connect at least one spring brake cylinder, and a trailer control port, an inlet-outlet valve unit configured to control a spring brake pressure, and an electropneumatic pilot control unit configured to control at least one control pressure at the inlet-outlet valve unit and configured to perform a trailer control position function. The electropneumatic pilot control unit includes a 3/3-way valve that has a first switching position in which the at least one control pressure is controlled, a second switching position in which the trailer control position function is carried out, and a third switching position in which the inlet-outlet valve unit and the trailer control port are connected to a vent.

A trailer control valve for a tractor includes a body defining a supply port and first and second delivery ports. The supply port is configured for fluid communication with a fluid source on the tractor. The first and second delivery ports are configured for fluid communication with glad-hand connectors through which fluid is supplied from the tractor to a trailer for, respectively, releasing a parking brake and applying a service brake. The first delivery port is in fluid communication with the supply port. A relay valve is supported within the body and includes a valve member configured to move between positions preventing and permitting fluid communication between the supply port and the second delivery port. Pressure transducers in the body generate pressure signals indicative of fluid pressure at the delivery ports permitting detection of the presence of a trailer coupled to the tractor.

A brake control signal amplification system that is designed to assist with the compliance to the FMVSS-121 Safety Standard for an air braked vehicle is described which comprises a trailer control module (TCM) that provides pneumatic signal to a trailer of the vehicle, a tractor protection valve (TPV) that protects a tractor air brake system in the event of a pneumatic disconnection from the trailer, and a pilot relay valve (PRV) coupled between the TCM and the TPV, wherein the PRV amplifies a control signal received from the TCM and delivers an amplified control signal to the to the TPV. The TPV delivers the amplified control signal to a control coupling for a trailer portion of a vehicle and delivers an air supply to a supply coupling for the trailer of the vehicle.

An electropneumatic parking brake module includes a supply port configured to connect a compressed air supply, a spring brake actuator port configured to connect at least one spring brake cylinder, and a trailer control port, an inlet-outlet valve unit configured to control a spring brake pressure, and an electropneumatic pilot control unit configured to control at least one control pressure at the inlet-outlet valve unit and configured to perform a trailer control position function. The electropneumatic pilot control unit includes a 3/3-way valve that has a first switching position in which the at least one control pressure is controlled, a second switching position in which the trailer control position function is carried out, and a third switching position in which the inlet-outlet valve unit and the trailer control port are connected to a vent.

A trailer control valve comprises a valve electronic control port adapted to receive an electronic control signal; a valve pneumatic supply port unrestrictedly fluidly communicating with a first supply of a pneumatic fluid; a valve pneumatic control port normally proportionally fluidly communicating with a second supply of the pneumatic fluid based on a pressure representing a driver brake demand, the first supply of the pneumatic fluid being in an independent pneumatic circuit from the second supply of the pneumatic fluid; and a valve delivery port selectively fluidly communicating with at least one of the valve pneumatic supply port and the valve pneumatic control port based on the electronic control signal, the pressure representing the driver brake demand and a pressure of the first supply of the pneumatic fluid. A first pneumatic check valve includes a first check valve supply port fluidly communicating with the first supply of the pneumatic fluid; and a first check valve delivery port fluidly communicating with the relay valve pneumatic supply port. The first pneumatic check valve controls the fluid communication of the first supply of the pneumatic fluid with the relay valve pneumatic supply port based on the pressure of the first supply of the pneumatic fluid at the valve pneumatic supply port.