Brake controller and method for controlling brake

1. A brake controller configured to be applied to a vehicle that includes a tractor and a trailer towed by the tractor, the brake controller comprising:

a first braking unit configured to control a first brake device installed in the tractor;

a second braking unit configured to control a second brake device installed in the trailer;

a distance sensor configured to detect a distance between the vehicle and an object located near the vehicle;

an execution unit configured to control the first braking unit and the second braking unit in accordance with the distance detected by the distance sensor and execute an automatic brake control that brakes the vehicle;

a coupling detection unit configured to detect that the tractor and the trailer are coupled to each other;

a failure diagnosis unit configured to diagnose the second braking unit with a failure; and

a prohibition unit configured to prohibit the execution unit from executing the automatic brake control,

wherein the prohibition unit is configured to prohibit the execution unit from executing the automatic brake control under the condition that the coupling detection unit has detected that the tractor and the trailer are coupled to each other and the failure diagnosis unit has detected that the second braking unit includes a failure.

2. The brake controller according to claim 1 , wherein

the execution unit is configured so that when prohibited by the prohibition unit from executing the automatic brake control, the execution unit controls the first control unit in accordance with the distance detected by the distance sensor and executes an abnormal state brake control instead of the automatic brake control to brake the vehicle, and

the first brake device generates a smaller braking force in the abnormal state brake control than in the automatic brake control.

3. A brake controller configured to be applied to a vehicle that includes a tractor and a trailer towed by the tractor, the brake controller comprising:

a first braking unit configured to control a first brake device installed in the tractor;

a second braking unit configured to control a second brake device installed in the trailer;

a distance sensor configured to detect a distance between the vehicle and an object located near the vehicle;

an execution unit configured to control the first braking unit and the second braking unit in accordance with the distance detected by the distance sensor and execute an automatic brake control that brakes the vehicle;

a coupling detection unit configured to detect that the tractor and the trailer are coupled to each other;

a failure diagnosis unit configured to diagnose the second braking unit with a failure;

a traveling state detection unit configured to detect a traveling state of the vehicle;

a straight traveling determination unit configured to determine whether or not the traveling state detection unit has detected that the vehicle is traveling straight; and

a prohibition unit configured to prohibit the execution unit from executing the automatic brake control,

wherein the prohibition unit is configured to prohibit the execution unit from executing the automatic brake control under the condition that the coupling detection unit has detected that the tractor and the trailer are coupled to each other, the failure diagnosis unit has detected that the second braking unit includes a failure, and the straight traveling determination unit has determined that the vehicle is not traveling straight.

4. The brake controller according to claim 2 , wherein

the execution unit is configured so that when prohibited by the prohibition unit from executing the automatic brake control, the execution unit controls the first control unit in accordance with the distance detected by the distance sensor and executes an abnormal state brake control instead of the automatic brake control to brake the vehicle, and

the first brake device generates a smaller braking force in the abnormal state brake control than in the automatic brake control.

5. A method for controlling a brake applied to a vehicle that includes a tractor and a trailer towed by the tractor, the method comprising:

controlling a first brake device installed in the tractor with a first braking unit;

controlling a second brake device installed in the trailer with a second braking unit;

detecting a distance between the vehicle and an object located near the vehicle;

controlling the first braking unit and the second braking unit in accordance with the detected distance and executing an automatic brake control that brakes the vehicle;

detecting that the tractor and the trailer are coupled to each other;

diagnosing the second braking unit for a failure; and

prohibiting execution of the automatic brake control under the condition that the tractor and the trailer are detected as being coupled and the second braking unit is diagnosed as including a failure.

6. A method for controlling a brake applied to a vehicle that includes a tractor and a trailer towed by the tractor, the method comprising:

controlling a first brake device installed in the tractor with a first braking unit;

controlling a second brake device installed in the trailer with a second braking unit;

detecting a distance between the vehicle and an object located near the vehicle;

controlling the first braking unit and the second braking unit in accordance with the detected distance and executing an automatic brake control that brakes the vehicle;

detecting that the tractor and the trailer are coupled to each other;

diagnosing the second braking unit for a failure;

detecting a traveling state of the vehicle;

determining whether or not the vehicle is traveling straight;

and

prohibiting execution of the automatic brake control under the condition that the tractor and the trailer are detected as being coupled, the second braking unit is diagnosed as including a failure, and that the vehicle is determined as not traveling straight.