Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/68—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings
  • F16H61/684—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive
  • F16H61/688—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive with two inputs, e.g. selection of one of two torque-flow paths by clutches
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18009—Propelling the vehicle related to particular drive situations
  • B60W30/18072—Coasting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H59/00—Control inputs to control units of change-speed- or reversing-gearings for conveying rotary motion
  • F16H59/14—Inputs being a function of torque or torque demand
  • F16H59/18—Inputs being a function of torque or torque demand dependent on the position of the accelerator pedal
  • F16H2059/186—Coasting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H59/00—Control inputs to control units of change-speed- or reversing-gearings for conveying rotary motion
  • F16H59/36—Inputs being a function of speed
  • F16H59/38—Inputs being a function of speed of gearing elements
  • F16H59/42—Input shaft speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H59/00—Control inputs to control units of change-speed- or reversing-gearings for conveying rotary motion
  • F16H59/48—Inputs being a function of acceleration

Definitions

• TITLE METHOD FOR CONTROLLING A DCT TRANSMISSION IN ENERGY RECOVERY
• the invention relates, in general, to the technical field of the management of the control of a powertrain of a motor vehicle equipped with a hybrid powertrain associated with a DCT type transmission.
• the invention controls the DCT type transmission, in particular e-DCT, by recovering energy when the speed of a primary gearbox shaft is lower than an idling speed of a thermal engine.
• the example of implementation of the invention described is a hybrid motor vehicle whose driving power is alternately or cumulatively provided by a heat engine and an electric machine supplied with electrical energy by batteries.
• the heat engine and the electric machine form a motor assembly whose driving energy is transmitted by a DCT type transmission device to a front or rear wheel set.
• This example of implementation of the invention was chosen to facilitate the description of the invention, without however being limited thereto. Indeed, the invention can also, for example, apply to a motor vehicle in which the driving energy is transmitted to more than one wheel set.
• a control device makes it possible to ensure the transmission to the drive wheel set of an engine torque generated by the heat engine, the electric machine or both.
• This control device manages a first clutch connecting the engine assembly to a first gearbox comprising odd transmission ratios, and a second clutch connecting the engine assembly to a second gearbox comprising even transmission ratios.
• the rotation speed of the wheels of the drive train returned to a primary shaft of the gearbox may be lower than a rotation speed of the thermal engine of the hybrid motor vehicle.
• the thermal engine has a minimum rotation speed, called idle speed, below which it cannot go down. Typically, this idle speed is of the order of 900 rpm.
• control device is programmed to slide the clutch between the heat engine and the primary shaft of the gearbox. In the event of deceleration, there is a loss of braking energy which cannot be recovered by the electric machine in order to charge the batteries.
• the invention aims to remedy all or part of the drawbacks of the state of the art by proposing in particular a solution allowing control of the DCT type transmission allowing efficient recovery of braking energy when driving at low speed.
• a method for controlling a DCT transmission of a motor vehicle comprising a powertrain comprising a heat engine and a DCT type transmission device comprising an electric machine, a gearbox having a primary shaft, a coupling clutch between the heat engine and the primary shaft 6, a gear train kinematically connecting the primary shaft to a input of the electric machine; the hybrid motor vehicle decelerating and the electric machine being in generator mode, the method comprises steps of:
• a primary shaft rotation speed falls below a threshold value RAP, change from a transmission ratio then engaged in the gearbox to a slightly lower transmission ratio, if possible.
• the method prior to the change step comprises a step of:
• the coupling clutch opens and the thermal engine stops.
• a powertrain for a motor vehicle comprising a heat engine and a DCT type transmission device comprising an electric machine, a gearbox having a primary shaft, a coupling clutch between the heat engine and the primary shaft, a gear train kinematically connecting the primary shaft to an input of the electric machine, as well as a computer arranged so as to implement the method having one of the preceding technical characteristics.
• the transmission device comprises a first gearbox coupled to the primary shaft via a coupling clutch and a second gearbox coupled to the primary shaft via a coupling clutch.
• a motor vehicle comprising a powertrain having one of the preceding technical characteristics.
• FIG. 1 a diagram of a powertrain of a hybrid motor vehicle intended to be driven by a driving method according to the invention
• FIG. 2 a graph of the evolution of the primary shaft speed and the driving speed for the first three gearbox ratios illustrating the operation of the control method according to the invention.
• FIG. 1 schematically illustrates a powertrain 1 of a hybrid motor vehicle in which a method for controlling a DCT transmission according to the invention will be implemented.
• the powertrain 1 drives a front or rear wheel set 2.
• the powertrain drives two or more wheel sets.
• the powertrain 1 is here a hybrid powertrain.
• the latter comprises a heat engine 3, a DCT type transmission device 4.
• the DCT type transmission device is here an e-DCT type transmission device in that it comprises an electric machine 5.
• the DCT type transmission device 4 comprises a primary shaft 6 and a coupling clutch KO between the heat engine 3 and the primary shaft 6.
• the DCT type transmission device 4 also comprises a gear train 65 connecting the electric machine 5 to the primary shaft 6.
• the DCT 4 type transmission device comprises, in a manner known per se, a first gearbox 41, comprising odd transmission ratios, a first clutch K1 for coupling between the primary shaft 6 and that of the first gearbox 41, a second gearbox 42, comprising even transmission ratios, and a second clutch K2 for coupling between the primary shaft 6 and that of the second gearbox 42.
• the electric machine 5 is electrically connected to a battery 8. In traction mode, the battery 8 thus supplies the electric machine and, in recovery mode, the electric machine, controlled as a generator, thus supplies the battery 8.
• a control device or calculator 9 makes it possible to manage the operation of the hybrid powertrain 1, in particular the DCT type transmission device 4.
• the control device or calculator 9 is arranged so as to be able to implement the method for controlling a DCT transmission according to the invention which will now be described in more detail.
• a torque is provided by the wheel set 2 and the electric machine 5 is driven in generator mode in order to charge the battery 8.
• the electric machine 5 is driven here in mode.
• a deceleration braking phase can then induce a driving speed of the hybrid motor vehicle brought back, initially, to a rotation speed value of the primary shaft 6 (due to the gear reduction due to the transmission ratio then engaged within one of the first 41 and second 42 gearboxes) which is lower than the idling speed of the heat engine 3.
• the method for controlling a DCT transmission comprises a step of opening the coupling clutch KO and stopping the heat engine 3.
• the primary shaft 6 is separated from the heat engine and remains only kinematically connected to the electric machine 5 via the gear train 65.
• the transmission ratio then engaged within one of the first 41 and second 42 gearboxes is retained.
• the method for controlling a DCT transmission determines whether a rotation speed value of the primary shaft 6 is less than a threshold value RAP of the electric machine 5. This threshold value RAP is determined so that the electric machine 5 in generator mode can charge the battery 48. This threshold value RAP is less than or equal to the idling speed of the heat engine 3. [0026] If the value of the rotation speed of the primary shaft 6 is indeed, the method for controlling a DCT transmission according to the invention comprises a step of lowering the transmission ratio then engaged within one of the first 41 and second 42 gearboxes to a transmission ratio just lower. This is no longer possible when the transmission ratio then engaged is the 1st .
• the method for controlling a DCT transmission according to the invention lowers the transmission ratio to 2nd when the value of the rotation speed of the primary shaft 6 falls below the threshold value RAP. From then on, the value of the rotation speed of the primary shaft 6 increases by “passing” from the speed curve of 3rd to the speed curve of 2nd . Then, as the driving speed continues to decrease, the rotation speed value of the primary shaft 6 again falls below the threshold value RAP: the method for controlling a DCT transmission according to the invention then lowers the transmission ratio to 1st and the rotation speed value of the primary shaft increases by “passing” from the speed curve of 2nd to that of 1st .
• the implementation of the method for controlling a DCT transmission according to the invention makes it possible to avoid slippage of the coupling clutches KO, K1 and K2, sources of recovery energy losses, and therefore to have efficient charging of the battery 8 by the electric machine 5 in generator mode, in particular during decelerations at low driving speed of the hybrid motor vehicle.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Transportation (AREA)
• Hybrid Electric Vehicles (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Control Of Transmission Device (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=86851665

Family Applications (1)

Country Status (3)

Family Cites Families (5)

• 2023
  • 2023-03-27 FR FR2302871A patent/FR3147218B1/fr active Active
• 2024
  • 2024-02-07 EP EP24707608.6A patent/EP4689452A1/de active Pending
  • 2024-02-07 WO PCT/FR2024/050163 patent/WO2024200933A1/fr not_active Ceased

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