Control of a change-gear transmission

• US 10,641,349 B2
• Filed: 04/26/2018
• Issued: 05/05/2020
• Est. Priority Date: 04/26/2017
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Rothmund, Hermann, Schilder, Boris, Eggert, David
• Primary Examiner(s): Dang, Tinh
• Application Number:
  US15/963,177
• Publication Number:
  US 20180313415A1
• Time in Patent Office: 740 Days
• CPC Class Codes: B60Y 2300/18083 without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60Y 2400/71 Manual or semi-automatic, e.g. automated manual transmissions
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/1045 Friction clutch
• CPC Class Codes: F16D 2500/30806 Engaged transmission ratio
• CPC Class Codes: F16D 2500/3108 Vehicle speed
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/31466 Gear lever
• CPC Class Codes: F16D 2500/5085 Coasting
• CPC Class Codes: F16D 48/068 using signals from a manually actuated gearshift linkage
• CPC Class Codes: F16H 2063/426 with means for advising the driver for proper shift action, e.g. prompting the driver with allowable selection range of ratios
• CPC Class Codes: F16H 59/044 consisting of electrical switches or sensors range selectors with electric switches or sensors F16H59/105
• CPC Class Codes: F16H 61/0248 Control units where shifting is directly initiated by the driver, e.g. semi-automatic transmissions generation of movements for final actuating mechanisms F16H61/28
• CPC Class Codes: F16H 63/42 Ratio indicator devices
• CPC Class Codes: F16H 63/46 Signals to a clutch outside the gearbox
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

A change-gear transmission system includes a transmission that can be switched between multiple gears, a gearshift lever for selecting between the gears of the transmission, an automatically actuatable clutch, which is arranged in a drive train in series with the transmission and a control unit for automatically opening the clutch while maintaining a gear engaged in the transmission when a condition for the transition into coasting or gliding mode is fulfilled. The control unit is configured to detect a touch of the gearshift lever by the driver, to open the clutch only when no touch of the gearshift lever is detected, and further in the case that in the coasting or gliding mode, a touch of the gearshift lever is detected, to close the clutch while maintaining the engaged gear.

Claims

1. A change-gear transmission system for a vehicle comprising:

a transmission switchable between a plurality of gears;

a gearshift lever for selectively engaging one of the plurality of gears;

a clutch assembly arranged in a drive train in series with the transmission and operable to configure the drive train in a coasting mode;

an actuator coupled to the clutch assembly and operable to open and close the clutch assemble; and

a control unit configured to detect a touch of the gearshift lever and to determine a condition for transiting the drive train into the coasting mode, wherein the control unit operates the actuator to open the clutch assembly when the condition for transiting into the coasting mode is fulfilled and the gearshift lever is not touched.

2. The change-gear transmission system according to claim 1, wherein the drive train is in the coasting mode and the control unit is further configured to close the clutch assembly while maintaining an engaged gear when a touch of the gearshift lever is detected.

3. The change-gear transmission system according to claim 2, wherein the condition comprises an actuation condition of an accelerator pedal indicating that the accelerator pedal is unactuated or only slightly actuated so that the direction of torque transmission in the drive train is inverted.

4. The change-gear transmission system according to claim 2, wherein the gearshift lever is movable between a plurality of shifting positions, wherein each gear of the transmission is assigned exactly one shifting position.

5. The change-gear transmission system according to claim 2, wherein the control unit is configured to check if a currently engaged gear is appropriate for a vehicle speed prior to a closing of the clutch, and closing the clutch only when the currently engaged gear is appropriate for the vehicle speed.

6. The change-gear transmission system according to claim 5, wherein the control unit is configured to determine an appropriate gear for the vehicle speed and to indicate the appropriate gear.

7. The change-gear transmission system according to claim 2, further comprising a proximity sensor on the gearshift lever in data communication with the control unit for detecting the touch of the gearshift lever by the driver.

8. The change-gear transmission system according to claim 2, further comprising a position sensor for the gearshift lever in data communication with the control unit to detect a change of the position of the gearshift lever indicating the touch of the gearshift lever by the driver.

9. A method for controlling a change-gear transmission system having a transmission switchable between a plurality of gears, a gearshift lever for selectively engaging one of the plurality of gears, a clutch assembly arranged in a drive train in series with the transmission and operable to configure the drive train in a coasting mode, an actuator coupled to the clutch assembly and operable to open and close the clutch assemble, and a control unit configured to selectively control the actuator, the method comprising:

determining when a first condition for opening the clutch assembly is fulfilled;

determining a second condition when the gearshift lever is untouched; and

opening the clutch when the first and second conditions are fulfilled.

10. The method for controlling according to claim 9, wherein the drive train is in the coasting mode and the method further comprises closing the clutch assembly while maintaining an engaged gear when a touch of the gearshift lever is detected.

11. The method according to claim 10, further comprising:

determining when the engaged gear is appropriate for a vehicle speed; and

closing the clutch assembly when the engaged gear is appropriate for the vehicle speed.

12. The method according to claim 11, further comprising:

determining an appropriate gear for the vehicle speed; and

indicating the appropriate gear when the engaged gear is different than the appropriate gear.

13. A non-transitory computer readable medium comprising program instructions, which when executed on a computer enable the computer to:

determine when a first condition for opening the clutch assembly is fulfilled;

determine a second condition when the gearshift lever is untouched;

open the clutch when the first and second conditions are fulfilled;

close the clutch assembly while maintaining an engaged gear when a touch of the gearshift lever is detected, and the drive train is in the coasting mode.

14. The non-transitory computer readable medium according to claim 13, further comprising the program instructions, which when executed on the computer enable the computer to:

determine when the engaged gear is appropriate for a vehicle speed; and

close the clutch assembly when the engaged gear is appropriate for the vehicle speed.

15. The non-transitory computer readable medium according to claim 13, further comprising the program instructions, which when executed on the computer enable the computer to:

determine an appropriate gear for the vehicle speed; and

indicate the appropriate gear when the engaged gear is different than the appropriate gear.