Heavy duty vehicle redundant braking system

Abstract

An electronically controlled pneumatic brake system for a vehicle, with a normal brake operating mode (NOM) and a backup brake operating mode (BKM), said system comprising: —a front axle brake module (FBM) for providing pneumatic control pressure to the left and right front pneumatic brake actuators (FW-L, FW-R), one or more rear axle brake module (RBM) for providing pneumatic control pressure to the left and right rear pneumatic brake actuators (RW-L,RW-R), a trailer brake interface(5), —an air production module (6) selectively providing air under pressure to said axles electronic brake modules (FBM,RBM) via first and second air supply circuits (AC1,AC2), a trailer relay valve (1), wherein each of the front and rear axle brake modules (FBM,RBM) is controlled by an electrical control signal (NBC,ES1,ES2) under the normal brake operating mode (NOM) and is controlled by a pneumatic backup brake control line (BKC) under the backup brake operating mode (BKM), wherein the output (12) of trailer relay valve is connected to the trailer brake interface(5) under the normal brake operating mode (NOM), and the output (12) of trailer relay valve is connected to the pneumatic backup brake control line (BKC) under the backup brake operating mode (BKM).

1 . An electronically controlled pneumatic brake system for an automotive vehicle, the system being configured to operate either under a normal brake operating mode or under a backup brake operating mode, the system comprising:
 at least one front axle brake module for providing pneumatic control pressure to the left and right front pneumatic brake actuators;   at least one rear axle brake module for providing pneumatic control pressure to the left and right rear pneumatic brake actuators;   a trailer brake interface and a coupling device for supplying air to a trailer;   an air production module selectively providing air under pressure to the front and rear axle electronic brake modules via at least a first air supply circuit and a second air supply circuit, and to a trailer circuit;   at least two air reservoirs, respectively connected to first and second air supply circuits; and   a trailer relay valve, having an output, wherein:
 each of the front and rear axle brake modules is controlled by an electrical control signal under the normal brake operating mode and is controlled by a pneumatic backup brake control line under the backup brake operating mode; and 
 the output of the trailer relay valve is connected to the trailer brake interface under the normal brake operating mode, and the output of the trailer relay valve is connected to the pneumatic backup brake control line under the backup brake operating mode. 
   
     
     
         2 . The brake system of  claim 1 , comprising a switchover auxiliary valve for connecting selectively the output of the trailer relay valve either to the trailer brake interface or to the pneumatic backup brake control line, depending on the current operating mode, and controlled by at least a backup mode selection valve. 
     
     
         3 . The brake system of  claim 2 , wherein the switchover auxiliary valve is a 4/2 valve with four ports and two plunger positions, with a pneumatic control. 
     
     
         4 . The brake system of  claim 2 , wherein the backup mode selection valve is an ON/OFF electro-valve, with its output connected to the pneumatic control port of the switchover auxiliary valve. 
     
     
         5 . The brake system of  claim 2 , further comprising a select low valve with output of the select low valve connected to the pneumatic control port of the switchover auxiliary valve. 
     
     
         6 . The brake system of  claim 5 , wherein one input port of the select low valve is supplied by the supply line to trailer brake interface, and the other input port of the select low valve is supplied by the backup mode selection valve. 
     
     
         7 . The brake system of  claim 6 , wherein the backup mode selection valve is a normally open valve. 
     
     
         8 . The brake system of  claim 7 , wherein the backup mode selection valve is controlled by an air production module control unit housed in the air production module. 
     
     
         9 . The brake system of  claim 1 , further comprising a proportional trailer control solenoid valve, to provide a control pressure to the trailer relay valve. 
     
     
         10 . The brake system of  claim 1 , further comprising:
 a service brake electric input device delivering a first input electric signal; and   at least one electronic brake control unit configured to process the first input electric signal, and to deliver electrical control signals towards the front and rear axle brake modules.   
     
     
         11 . The brake system of  claim 10 , wherein the pneumatic backup brake control line is output and controlled by the air production module, independently of the brake control unit and/or autonomous drive control units. 
     
     
         12 . The brake system of  claim 1 , further comprising:
 a truck parking brake relay valve;   a parking brake electric input device delivering a second input electric signal; and   an air production module control unit adapted to process the second input electric signal, and to deliver control signals to a proportional park brake control solenoid valve, which provides a control pressure to the parking brake relay valve.   
     
     
         13 . The brake system of  claim 1 , wherein the switchover auxiliary valve, the backup mode selection valve, and optionally the select low valve are housed within the air production module. 
     
     
         14 . The brake system of  claim 1 , wherein there is provided a third air supply circuit for providing a redundant pneumatic supply to the front and rear axle brake modules. 
     
     
         15 . A vehicle comprising an electronically controlled pneumatic brake system, the system being configured to operate either under a normal brake operating mode or under a backup brake operating mode, the system comprising:
 at least one front axle brake module for providing pneumatic control pressure to the left and right front pneumatic brake actuators;   at least one rear axle brake module for providing pneumatic control pressure to the left and right rear pneumatic brake actuators;   a trailer brake interface and a coupling device for supplying air to a trailer;   an air production module selectively providing air under pressure to the front and rear axle electronic brake modules via at least a first air supply circuit and a second air supply circuit, and to a trailer circuit;   at least two air reservoirs, respectively connected to first and second air supply circuits; and   a trailer relay valve, having an output, wherein:
 each of the front and rear axle brake modules is controlled by an electrical control signal under the normal brake operating mode and is controlled by a pneumatic backup brake control line under the backup brake operating mode; and 
 the output of the trailer relay valve is connected to the trailer brake interface under the normal brake operating mode, and the output of the trailer relay valve is connected to the pneumatic backup brake control line under the backup brake operating mode.