Trailer panic braking assist

1 . A method for improving trailer brake response during a hard braking event, the method comprising the steps of:

monitoring primary trailer brake control signals sent by a trailer brake controller in response to tow vehicle operator inputs;

detecting trailer brake controller attenuation of the trailer brake control signals; and

responding to the detected attenuation of the trailer brake control signals by sending secondary trailer brake control signals commanding brakes of a trailer to apply greater braking force than that being commanded by the primary trailer brake control signals.

2 . The method of claim 1 in which:

the monitoring step includes monitoring a brake force control parameter of the primary trailer brake control signals; and

the detecting step includes a determination that the monitored brake force control parameter of the primary trailer brake control signals has remained steady within a predetermined range for a predetermined minimum period of time.

3 . The method of claim 2 in which:

the monitored brake force control parameter comprises electrical voltage of the primary trailer brake control signals; and

the detecting step includes a determination that the voltage of the primary trailer brake control signals has remained steady within a predetermined voltage range for the predetermined minimum period of time.

4 . The method of claim 3 in which:

the detecting step also includes determining that the voltage of the primary trailer brake signals is above a minimum threshold value; and

execution of the responding step is further conditioned upon a determination that the voltage of the primary trailer brake signal is above the minimum threshold.

5 . The method of claim 1 in which:

claim 1 includes the additional step of monitoring a parameter of motion sensed by a motion sensor that senses motion of at least a portion of at least one of the trailer and the tow vehicle; and

execution of the responding step is further conditioned upon the monitored parameter exceeding a predetermined threshold value during a period of time before which attenuation of primary trailer brake control signals has been detected.

6 . The method of claim 5 in which the monitored parameter of motion is acceleration.

7 . The method of claim 5 in which the responding step additionally comprises increasing braking force of the secondary trailer brake control signals by an amount corresponding to a change in the monitored parameter of motion.

8 . The method of claim 1 in which:

claim 1 includes the additional step of monitoring a speed of at least a portion of at least one of the trailer and the tow vehicle;

the detecting step also includes a determination that the speed is above a minimum threshold value; and

the responding step is further conditioned upon the determination that the speed is above a minimum threshold value.

9 . The method of claim 8 in which:

the monitoring step includes monitoring signals that are generated by and received from a speed sensor, and that correspond to the speed of at least a portion of at least one of the trailer and tow vehicle; and

the speed sensor comprises wheel speed sensors positioned so that the rotational speed of each wheel of the trailer is monitored by a wheel speed sensor.

10 . The method of claim 9 in which the speed determined in the detecting step is the speed of the trailer calculated based on the rotational speed of the trailer wheels.

11 . The method of claim 1 including the additional step of ceasing to send secondary trailer brake signals that differ from the primary trailer brake control signals, in response to at least one disengagement criterion selected from the group of criteria consisting of:

speed sensed by a speed sensor falls below a predetermined minimum value;

primary trailer brake control signals received from the trailer brake controller fall below a predetermined minimum voltage value for a predetermined period of time;

primary trailer brake control signals received from the trailer brake controller fall below a minimum voltage value, and acceleration increases by a minimum value relative to the acceleration value at the time that the detecting step was completed; or

primary trailer brake control signals received from the trailer brake controller rise by more than a predetermined maximum value of change in voltage relative to the voltage value of the primary trailer brake control signals at the time that the detecting step was completed.

12 . The device of claim 1 in which the motion sensor comprises one or more wheel speed sensors positioned to sense the speed of wheels of the trailer.

13 . The device of claim 1 in which the motion sensor comprises an accelerometer mounted to the trailer and sensing accelerations of the trailer.

14 . The device of claim 1 in which the motion sensor signal input is connected to receive signals from motion sensors including both accelerometer and wheel speed sensors mounted to the trailer.

15 . The device of claim 1 in which the brake booster comprises a power supply, and the brake booster is connected to and draws power from the power supply to increase the voltage of braking commands received by the trailer brakes relative to the primary trailer brake control signals received by the brake signal input.

16 . A trailer brake assist device for improving trailer brake response during a hard braking event, the device comprising:

a trailer brake signal input connected to receive primary trailer brake control signals from a trailer brake controller;

a motion sensor signal input connected to receive trailer motion signals from at least one motion sensor positioned to detect motion of at least part of a trailer;

a trailer brake signal output connected to send secondary trailer brake signals to trailer brakes of the trailer;

an attenuation detector preconfigured to detect when primary trailer brake signals received by the trailer brake signal input have been attenuated by the trailer brake controller; and

a brake booster preconfigured to increase the braking commands received by the trailer brakes relative to the primary trailer brake control signals received by the brake signal input by sending secondary brake signals from the brake signal output, in response to detection of attenuation by the attenuation detector.

17 . The device of claim 16 in which:

the device is a component of a trailer antilock brake system;

the motion sensor signal input is connected to and receives signals from an inertial measurement unit of the antilock brake control system;

the motion sensor signal input is connected to and receives signals from wheel speed sensors of the antilock brake control system; and

the brake booster is a component of a controller of the trailer antilock brake system.

18 . The device of claim 16 in which the brake booster is preconfigured to increase the braking commands received by the trailer brakes relative to the primary trailer brake control signals received by the brake signal input by sending secondary brake signals from the brake signal output in response to both detection of attenuation by the moderation detection feature, and in response to signals received by the motion sensor signal input.

19 . The device of claim 18 in which the brake booster is preconfigured to increase the braking commands received by the trailer brakes relative to the primary trailer brake control signals received by the brake signal input by sending secondary brake signals from the brake signal output when the attenuation detector detects that a brake force control parameter of the trailer brake control signals has remained steady within a predetermined range for a predetermined minimum period of time.