Trailer vehicle and trailer brake controller, and method and computer program product therefor
A method for controlling, via a trailer vehicle configured to be coupled to a towing vehicle with an electric drive, the electric drive of the towing vehicle includes receiving, via a trailer brake control unit of the trailer vehicle, a current accelerator pedal position from the towing vehicle. The method further includes generating a control signal for the electric drive with the trailer brake control unit depending on the received current accelerator pedal position and controlling the electric drive with the generated control signal.
1. A method for controlling, via a trailer vehicle configured to be coupled to a towing vehicle, an electric drive of the trailer vehicle, the method comprising: receiving, via a trailer brake control unit of the trailer vehicle configured to control friction brakes of the trailer vehicle, a current accelerator pedal position from the towing vehicle, generating a control signal for the electric drive of the trailer vehicle with the trailer brake control unit depending on the received current accelerator pedal position, and controlling the electric drive with the control signal generated by the trailer brake control unit, wherein the current accelerator pedal position is received via an ISO 11992-2 CAN bus in message EBS 11 according to ISO 11992-2, and wherein the control signal is output via the ISO 11992-2 CAN bus to a vehicle brake control unit of the towing vehicle, the control signal being output in message (21) according to ISO 11992-2 as a relative value and/or message (23) according to ISO 11992-2 as an absolute value, and wherein a request signal for a vehicle control unit is generated in the vehicle brake control unit as a function of the generated control signal.
2. The method as claimed in claim 1 , further comprising detecting a state of charge of at least one accumulator of the electric drive by the trailer brake control unit, wherein the control signal for the electric drive is generated with the trailer brake control unit depending on the received accelerator pedal position and further depending on the detected state of charge.
3. The method as claimed in claim 1 , wherein the generating the control signal includes:
detecting or providing a current speed of the trailer vehicle in the trailer brake control unit,
determining a maximum torque value of the electric drive using a torque characteristic curve with speed-dependent maximum torque values and the detected or provided current speed,
determining a control torque value depending on the accelerator pedal position and the determined maximum torque value, and
outputting, to the electric drive as the generated control signal, the determined control torque value or a control torque value adjusted depending on the determined control torque value.
4. The method as claimed in claim 3 , wherein a state of charge of an accumulator of the electric drive is detected by the trailer brake control unit, and wherein the control torque value generated by the trailer brake control unit is adjusted depending on the detected state of charge, and wherein the adjusted control torque value is output, to the electric drive, as the generated control signal.
5. The method as claimed in claim 4 , wherein the control torque value is adjusted such that:
in response to the state of charge of the at least one accumulator being above a predefined threshold value or threshold value range, the control torque value is increased by a predefined value or a predefined relative value of the control torque value, or
in response to the state of charge of the at least one accumulator being below the predefined threshold value or threshold value range, the control torque value is reduced by the or another predefined value or the or another predefined relative value of the control torque value.
6. The method as claimed in claim 1 , wherein generating the control signal includes:
determining a currently expected accelerator pedal position of the towing vehicle of the trailer vehicle,
comparing the received current accelerator pedal position with the expected accelerator pedal position to determine a comparison value, and
generating the control torque value as the control signal for the electric drive additionally depending on the comparison result.
7. The method as claimed in claim 6 , wherein the determination of a currently expected accelerator pedal position of the towing vehicle is dependent on an accelerator pedal position characteristic curve that indicates an expected accelerator pedal position depending on a current speed of the trailer vehicle.
8. The method as claimed in claim 7 , wherein the accelerator pedal position characteristic curve is adjusted depending on further conditions of the vehicle or the trailer vehicle.
9. The method as claimed in claim 1 , wherein the control torque value is determined by:
M
*
=
100
%
100
%
-
A
*
·
(
A
-
A
*
)
·
M
max
(
S
1
,
v
)
,
wherein
M* is the determined control torque value, A* corresponds to the expected accelerator pedal position, A corresponds to the received accelerator pedal position and M max (S1, v) corresponds to the maximum torque value depending on the current speed.
10. A trailer brake control unit for a trailer vehicle, wherein the trailer brake control unit is configured to carry out a method as claimed in claim 1 .
11. A vehicle with a trailer brake control unit as claimed in claim 10 .
12. A non-transitory computer-readable medium having processor-executable instructions stored thereon, wherein the processor-executable instructions, when executed by one or more processors, facilitate performance of the method of claim 1 .
13. The method according to claim 1 , wherein the trailer brake control unit includes a sensor configured to convert a brake control pressure received from the towing vehicle into an electric signal.
14. The method according to claim 13 , further comprising:
determining, via the trailer brake control unit, that transmission of a negative acceleration signal from the towing vehicle to the trailer brake control unit has failed; and
controlling the friction brakes of the trailer vehicle based on the brake control pressure.
15. A vehicle brake control unit for a towing vehicle, wherein the vehicle brake control unit is configured to output an accelerator pedal position via an ISO 11992-2 CAN bus in message EBS 11 according to ISO 11992-2, and to receive a control signal output in message (21) and/or message (23) according to ISO 11992-2, from a trailer brake control unit, for controlling an electric drive of a trailer vehicle, which is configured to be coupled to the towing vehicle via the ISO 11992-2 CAN bus.
16. The vehicle brake control unit as claimed in claim 15 , wherein the vehicle brake control unit is configured to, depending on the control signal, output a request signal for a vehicle control unit of the towing vehicle.