Method and device for safely braking a trailer

An electronically controllable pneumatic motor vehicle braking system for a motor vehicle of a vehicle combination, the electronically controllable pneumatic motor vehicle braking system comprising:

• a service brake system having a trailer control valve with a trailer feed port for connecting a trailer feed line and a trailer brake pressure port for connecting a trailer control line, at least one trailer brake circuit on a motor vehicle side for supplying said trailer control valve with a supply pressure, wherein said trailer control valve is configured to make available a trailer supply pressure at said trailer feed port;
• a primary brake control unit for controlling the service brake system, wherein said primary brake control unit is connected to a unit for autonomous driving and receives braking demand signals from the unit for autonomous driving;
• and,
• wherein the electronically controllable pneumatic motor vehicle braking system is configured, in response to a demand for safe braking of a trailer connected to the motor vehicle, to bring about lowering of the trailer supply pressure, with a result that spring brake actuators of the trailer are applied and safely brake the trailer.

A motor vehicle comprising:

• an autonomous driving unit;
• an electronically controllable pneumatic motor vehicle braking system including a service brake system and a primary brake control unit for controlling the service brake system;
• said service brake system having a trailer control valve with a trailer feed port for connecting a trailer feed line and a trailer brake pressure port for connecting a trailer control line, at least one trailer brake circuit on a motor vehicle side for supplying said trailer control valve with a supply pressure, wherein said trailer control valve is configured to make available a trailer supply pressure at said trailer feed port;
• said primary brake control unit being connected to a unit for autonomous driving and receives braking demand signals from said autonomous driving unit;
• and,
• said electronically controllable pneumatic motor vehicle braking system being configured, in response to a demand for safe braking of a trailer connected to the motor vehicle, to bring about lowering of the trailer supply pressure, with a result that spring brake actuators of the trailer are applied and safely brake the trailer.