Methods and apparatus for automatic calibration of electronic trailer brake gain

1. An apparatus comprising:

a threshold comparator to compare a calculated trailer brake torque to at least a first or a second threshold;

a gain adjustment manager to:

adjust a gain value based upon the calculated trailer brake torque satisfying at least one of the first or second thresholds;

increase the gain value when the calculated trailer brake torque is less than the first threshold;

decrease the gain value when the calculated trailer brake torque is greater than the second threshold; and

set the gain value as a calibrated gain value when the calculated trailer brake torque is greater than the first threshold and less than the second threshold; and

a brake signal applicator to generate a signal corresponding to a pressure to apply to a brake of a trailer based on the gain value.

2. The apparatus of claim 1 , further including a gain calibration initializer to initialize adjustment of the gain value when:

gain adjustment is configured to be on;

the trailer is detected to be coupled to a vehicle; and

an ignition cycle of the vehicle is detected.

3. The apparatus of claim 1 , wherein the first threshold is a lower limit defined by a minimum weight of the trailer and the second threshold is an upper limit defined by a maximum weight of the trailer, the lower limit and upper limit further defined by a deceleration of a vehicle and the trailer when brakes of the vehicle are applied.

4. The apparatus of claim 3 , wherein:

the minimum weight of the trailer is based upon a maximum weight of the vehicle subtracted from a train mass received from a vehicle communication network; and

the maximum weight of the trailer is based upon the minimum weight of the vehicle subtracted from the train mass.

5. The apparatus of claim 4 , wherein an initial gain value is calculated based on the train mass.

6. The apparatus of claim 1 , wherein the gain adjustment manager is further to:

receive a first user input from a display to at least one of reject or accept the calibrated gain value;

propagate the calibrated gain value to a vehicle communication network when the first user input accepts the calibrated gain value; and

modify the calibrated gain value per a second user input when the first user input rejects the calibrated gain value.

7. An apparatus comprising:

a trailer brake gain calibration module programmed to:

compare a calculated trailer brake torque to at least one of a first or second threshold, adjust a gain value based upon satisfaction of at least one of the first or second threshold;

increase the gain value when the calculated trailer brake torque is less than the first threshold;

decrease the gain value when the calculated trailer brake torque is greater than the second threshold; and

set the gain value as a calibrated gain value when the calculated trailer brake torque is greater than the first threshold and less than the second threshold; and

apply a pressure to a brake of a trailer based on the gain value.

8. The apparatus of claim 7 , wherein the trailer brake gain calibration module is further programmed to initialize adjustment of the gain value when:

gain adjustment is configured to be on;

the trailer is detected to be coupled to a vehicle; and

an ignition cycle of the vehicle is detected.

9. The apparatus of claim 7 , wherein the first threshold is a lower limit defined by a minimum weight of the trailer and the second threshold is an upper limit defined by a maximum weight of the trailer, the lower limit and upper limit further defined by a deceleration of a vehicle and the trailer when brakes of the vehicle are applied.

10. The apparatus of claim 9 , wherein:

the minimum weight of the trailer is based upon a maximum weight of the vehicle subtracted from a train mass received from a vehicle communication network; and

the maximum weight of the trailer is based upon the minimum weight of the vehicle subtracted from the train mass.

11. The apparatus of claim 10 , wherein an initial gain value is calculated based on the train mass.

12. The apparatus of claim 7 , wherein the trailer brake gain calibration module is further programmed to:

receive a first user input from a display to at least one of reject or accept the calibrated gain value;

propagate the calibrated gain value to a vehicle communication network when the first user input accepts the calibrated gain value; and

modify the calibrated gain value per a second user input when the first user input rejects the calibrated gain value.

13. A method comprising:

comparing a calculated trailer brake torque to at least a first threshold or a second threshold;

adjusting a gain value based upon the calculated trailer brake torque satisfying at least one of the first threshold or the second threshold;

in response to determining the calculated trailer brake torque is less than the first threshold, increasing the gain value;

in response to determining the calculated trailer brake torque is greater than the second threshold, decreasing the gain value; and

in response to determining the calculated trailer brake torque is greater than the first threshold and less than the second threshold, setting the gain value as a calibrated gain value; and

applying a pressure to a brake of a trailer based on the gain value.

14. The method of claim 13 , wherein the first threshold is a lower limit defined by a minimum weight of the trailer and the second threshold is an upper limit defined by a maximum weight of the trailer, the lower limit and upper limit further defined by a deceleration of a vehicle and the trailer when brakes of the vehicle are applied.

15. The method of claim 14 , wherein:

the minimum weight of the trailer is based upon a maximum weight of the vehicle subtracted from a train mass received from a vehicle communication network; and

the maximum weight of the trailer is based upon the minimum weight of the vehicle subtracted from the train mass.

16. The method of claim 15 , wherein an initial gain value is calculated based on the train mass.

17. The method of claim 13 , further including:

receiving a first user input from a display to at least one of reject or accept the calibrated gain value;

in response to the first user input accepting the calibrated gain value, propagating the calibrated gain value to a vehicle communication network; and

in response to the first user input rejecting the calibrated gain value, modifying the calibrated gain value per a second user input.