Method for operating a drive train for a mobile vehicle

Patent metadata

Field	Value
Publication number	US-10280854-B2
Application number	US-201715586511-A
Country	US
Kind code	B2
Filing date	May 4, 2017
Priority date	Jun 28, 2016
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

With a torque-controlled internal combustion engine and a variable-speed transmission having fixed shift gear ratios, during a shift, the internal combustion engine is controlled in such manner that the drive output torque of the transmission remains the same before and after the shift.

First claim

The invention claimed is:

1. A method of operating a drive-train of a mobile vehicle with an internal combustion engine and a transmission having at least shiftable first and second fixed gear ratios for powering a driving operation such that, when the transmission is shifted, the transmission shifts from the first fixed gear ratio to the second fixed gear ratio, the method comprising:
controlling the internal combustion engine with an electronic control unit so that the internal combustion engine is operated in a torque-controlled manner as a function of a position of an accelerator pedal;
during the shift from the first fixed gear ratio to the second fixed gear ratio, and with the accelerator pedal position unchanged, the electronic control unit controls torque of the internal combustion engine as a function of a gear ratio change in such a manner that the torque of the internal combustion engine is either increased or reduced such that delivered torque of the transmission remains the same; and
maintaining the torque of the internal combustion engine during the shift if a rotational speed of the internal combustion engine is below a predefined value before the shift.

2. The method of operating the drive-train according to claim 1 , further comprising, defining the shift as a downshift; and
during the downshift, reducing the torque delivered by the internal combustion engine by a factor of the gear ratio change.

3. The method of operating the drive-train according to claim 1 , further comprising, defining the shift as an upshift; and
during the upshift, increasing the torque delivered by the internal combustion engine by a factor of the gear ratio change.

4. The method of operating the drive-train according to claim 1 , further comprising limiting a maximum rotational speed that is reachable by the internal combustion engine as a function of the position of the accelerator pedal, and the limited rotational speed is lower than a theoretically possible rotational speed of the internal combustion engine.

5. A method of operating a drive-train of a mobile vehicle with an internal combustion engine and a transmission having at least shiftable first and second fixed gear ratios for powering a driving operation such that, when the transmission is shifted, the transmission shifts from the first fixed gear ratio to the second fixed gear ratio, the method comprising:
controlling the internal combustion engine with an electronic control unit so that the internal combustion engine is operated in a torque-controlled manner as a function of a position of an accelerator pedal;
during the shift from the first fixed gear ratio to the second fixed gear ratio, and with the accelerator pedal position unchanged, the electronic control unit controls torque of the internal combustion engine as a function of a gear ratio change in such a manner that the torque of the internal combustion engine is either increased or reduced such that delivered torque of the transmission remains the same;
limiting a maximum rotational speed that is reachable by the internal combustion engine as a function of the position of the accelerator pedal, and the limited maximum rotational speed is lower than a theoretically possible rotational speed of the internal combustion engine; and
limiting the maximum rotation speed of the internal combustion engine in such a manner that the internal combustion engine brakes the vehicle when the accelerator pedal position is set below a predefined value.

6. The method of operating the drive-train according to claim 5 , further comprising additionally actuating a retarder when the accelerator pedal position is set below a predefined value.

7. The method of operating the drive-train according to claim 6 , further comprising controlling the torque produced by the retarder as a function of the accelerator pedal position.

8. A method of operating a drive-train of a mobile vehicle with an internal combustion engine and a transmission having at least first and second fixed gear ratios that are shiftable for powering a driving operation, the method comprising:
initiating a transmission gear shift from the first fixed gear ratio to the second fixed gear ratio;
controlling a torque of the internal combustion engine with an electronic control unit as a function of a position of an accelerator pedal;
during the transmission gear shift from the first fixed gear ratio to the second gear ratio, and when the position of the accelerator pedal is unchanged, controlling the torque of the internal combustion engine with the electronic control unit as a function of a gear ratio change such that the torque of the internal combustion engine is either increased or reduced to maintain torque output by the transmission unchanged during the transmission gear shift from the first fixed gear ratio to the second gear ratio; and
maintaining the torque of the internal combustion engine during the transmission gear shift, if a rotational speed of the internal combustion engine is below a predefined value before the shift.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• LEGNER JüRGEN

Classifications

• F16H63/502

  for smoothing gear shifts · CPC title

• B60W10/11

  Stepped gearings · CPC title

• F02D2200/602

  Pedal position · CPC title

• F02D31/006

  for maximum speed control · CPC title

• F02D41/023 Primary

  in relation with the gear ratio shifting (conjoint control for improving gear change B60W30/19) · CPC title