Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/10—Introducing corrections for particular operating conditions for acceleration
  • F02D41/107—Introducing corrections for particular operating conditions for acceleration and deceleration
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
  • F02D41/3064—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes
  • F02D41/307—Controlling fuel injection according to or using specific or several modes of combustion with special control during transition between modes to avoid torque shocks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/10—Parameters related to the engine output, e.g. engine torque or engine speed
  • F02D2200/1006—Engine torque losses, e.g. friction or pumping losses or losses caused by external loads of accessories
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2250/00—Engine control related to specific problems or objectives
  • F02D2250/18—Control of the engine output torque
  • F02D2250/21—Control of the engine output torque during a transition between engine operation modes or states

Definitions

• the present invention relates to a control system of a motor-drive unit, controlled in torque, of a motor vehicle, the power unit being connected to wheels of the vehicle for their drive through a transmission having mechanical clearances.
• the invention is particularly aimed at attenuating jerks and oscillations of the transmission when crossing said mechanical clearances.
• a motor vehicle transmission comprises a primary shaft rotatably connected to the output shaft of the powertrain of the vehicle, and a secondary shaft fixed in rotation of wheels thereof, said driving wheels.
• the primary shaft and the secondary shaft of the transmission drive each other by means of gear sets selectable by means of a gearbox.
• FIG. 1 An example of mechanical play of the transmission is illustrated in FIG. 1 in which a transmission gear E comprises a first gear R1, for example mounted on the primary shaft, and a second gear wheel R2 mounted on the secondary shaft. .
• the gear wheels R1, R2 mesh with each other, but a tooth of one wheel does not fully occupy the space between two teeth of the other wheel. There is therefore a mechanical play in the illustrated gear.
• the wheel R1 rotates the wheel R2 in the direction illustrated by the arrows F, a tooth of the wheel R1 of the primary shaft abutting on a surface A of a tooth of the wheel R2 of the secondary shaft.
• Passage of the transmission game The transition from the configuration in solid lines to the configuration in phantom will be designated later "passage of the transmission game".
• the occurrence of such a passage depends on the torque applied to the transmission, that is to say that applied to the primary shaft by the powertrain and that applied to the secondary shaft by so-called motor wheels.
• a torque causing the passage of a mechanical play of the transmission will be referred to hereafter as "passing torque of a transmission set”.
• These systems comprise means for acquiring the resistive torque applied to the driving wheels (torque due to friction) and means for acquiring a torque set point for the desired power unit of the driver.
• These systems also include an information processing unit which estimates transmission play passage torques and limit the variation of the torque setpoint delivered to the power unit when a passing torque is detected. Once the game has passed, the information processing unit applies a barycentric filter to converge to the desired torque set by the driver.
• the estimate of transmission gears passage torques is based on the value of a torque applied by the powertrain to the transmission and reduced to the reference of the driving wheels. Such an estimate is generally of poor quality since there is a significant difference between the true value of a passing torque of a game and the estimated value thereof. It follows discontinuities in the calculated torque setpoint delivered to the power unit by the information processing unit such as slope breaks, which ultimately generate oscillations in the transmission.
• the object of the present invention is to solve the aforementioned problem by proposing a system for controlling the operation of a motor-vehicle power unit which accurately estimates the torque transmission passages and calculates torque instructions for a smooth and continuous passage of the transmission sets.
• the subject of the invention is a system for controlling the operation of a motor-drive unit controlled in motor vehicle torque, the power-train unit being connected to wheels of the vehicle for their drive through a transmission. having mechanical games, the system comprising:
• the first means of calculating the resistive torque brought back to the powertrain are able to calculate it according to the relation:
• CAP nat is the resistive torque brought back to the power unit
• C ext is the acquired resistive torque
• ⁇ is a reduction ratio of the transmission
• the wheel is an inertia of the motor vehicle brought back to the wheels
• the second means for calculating the approval instruction are suitable for calculating it so that it exhibits an attenuated temporal variation during the passage of said mechanical clearances;
• the second means for calculating the approval setpoint are suitable for calculating it so that it exhibits a substantially zero time variation during the passage of said mechanical clearances;
• the second means for calculating the approval instruction are able to calculate it so that it continues the torque setpoint acquired for the powertrain unit from the driver, once said mechanical clearances have passed;
• the second means for calculating the approval instruction are able to calculate it according to the following relation:
• Y ap H T e • ⁇ f n ] • ( C ap _ cns H ⁇ C ap _ cn _ agr [n - 1])
• CAP cns agr is the approval setpoint
• Cap cns is the desired torque setpoint by the driver
• CAP nat is the torque setpoint brought back to the powertrain
• T e is a predetermined sampling period
• n is an nth sampling instant
• ⁇ and ⁇ are variable or constant parameters
• the second calculation means are adapted to dynamically select the parameters ⁇ and ⁇ depending on the difference between the target torque calculated accreditation CAP C ns agr ⁇ t ' ⁇ torque reduced to the power train at n CAP group is -
• FIG. 2 is a schematic view of a traction chain of a motor vehicle associated with a system according to the invention.
• FIG. 3 is a graph of curve illustrating torque instructions obtained according to a system of the state of the art and the system according to the invention.
• This traction chain 10 comprises a motor-drive unit 12 (GMP) with a heat engine, controlled in torque and adapted to drive in rotation or to brake wheels 14, 16 of the vehicle through a transmission 18.
• GMP motor-drive unit 12
• heat engine controlled in torque and adapted to drive in rotation or to brake wheels 14, 16 of the vehicle through a transmission 18.
• the transmission 18, delimited by a closed line in phantom, comprises a primary shaft and a secondary shaft (not shown), a disengaging member 20, a gearbox 22, a differential bridge 24 and gimbals 26, 28 connecting respectively the bridge 24 to the wheels 14, 16.
• the disengaging member is included in the GMP between the thermal and electrical engines, as is known per se.
• the transmission 18 is conventional and therefore will not be described in more detail later.
• the transmission 18 has a certain number of mechanical clearances causing disturbances, such as jerks and oscillations, for torque values applied thereto by the wheels 14, 16 and the power unit 12, as has been previously described.
• the traction chain 10 is associated with a system 30 for controlling the operation of the GMP 12 capable of determining, and delivering thereto, a torque setpoint, called "preventive approval", which has the effect, when it is applied by the GMP 12, to significantly attenuate the disturbances caused by the passage of transmission games.
• the system 30 comprises a torque sensor 32 measuring the torque at the output of the GMP 12, a position sensor 34 measuring the position ⁇ p of the accelerator pedal of the vehicle, and a speed sensor 36 measuring the speed v of the vehicle.
• the system 30 also comprises a preventive approval unit 38, delimited by a closed line in phantom, connected to the sensors 32, 34 and 36.
• This unit 38 comprises a module 40 connected to the position sensor 34 and determining a torque setpoint Cap cns for the GMP 12 as a function of the measured position ⁇ p of the accelerator pedal.
• This instruction Cap cns corresponds to the torque that wishes to apply the conductor to the primary shaft of the transmission 18 and is for example determined by evaluation of a map stored in the module 40.
• the preventive approval unit 38 also comprises a module 42 for estimating the resistive torque C ext exerted on the wheels 14, 18 because of the different friction they undergo.
• the module 42 is connected to the torque sensor 32 and to the speed sensor 36 and estimates the resistive torque C ext as follows:
• the module 42 calculates the theoretical torque C GMP wheel ⁇ produced by the GMP at the wheels 14, 16 as a function of the measured torque, by the sensor 32 and a predetermined model of the transmission 18.
• the module 42 calculates the theoretical resistive torque C ext ⁇ exerted on the wheels 14, 16 as a function of the measured speed V of the vehicle and a predetermined model of the operation of the wheels 14, 16. From the theoretical resistive torque C ext ⁇ and the theoretical torque C GMP wheel th , the module 42 then determines a theoretical speed V th of the vehicle, then determines an additional resistive torque C ext ad exerted on the wheels as a function of the difference between the theoretical speed V th calculated and the speed real measured v of the vehicle.
• the resistive torque C ext exerted on the wheels 14, 16 is then calculated by the module 42 as the sum of the theoretical resistive torque C ext ⁇ and the additional resistive torque C ext ad .
• the calculation of the additional resistive torque C ext ad thus makes it possible to take into account uncertainties on the model of operation of the wheels 14, 16, as uncertainties on the slope of the road and the speed and direction of the wind for example.
• the preventive approval unit 38 also comprises a calculation module 44 connected to the module 42 for calculating the resistive torque C ext .
• the module 44 is able to calculate a CAP value nat is of resistive torque brought back to the GMP 12 corresponding to a passing torque of a transmission set.
• a pair C GMP AP applied to the wheels 14, 16 by the GMP 12 and brought back to the primary shaft of the transmission 18 can be modeled according to the relation:
• C traas is the torque transmitted by the transmission at the secondary shaft thereof, JVEH wheel ⁇ St 'inertia of the vehicle brought back to the wheels 14, 16, JQMP wheel ⁇ St ' inertia of the GMP 12 brought back to the wheels 14, 16 , and ⁇ is a reduction factor of the transmission depending on the engaged ratio of the gearbox and a reduction factor of the differential bridge 24 of the transmission 18.
• the torque C ⁇ s is momentarily zero.
• the toothed wheels R1 and R2 are between the configurations in solid lines and phantom lines, the primary shaft and the secondary shaft of the transmission are disconnected so that the transmitted torque
• the module 44 determines the resistive torque CAP nat is reduced to
• GMP 12 corresponding to a passing torque of a mechanical game according to the relation:
• the preventive approval unit 38 comprises a module 46 for calculating a torque set CAP cns agr of preventive approval. This module
• T e is a predetermined sampling period
• n is the nth sampling instant
• ⁇ and ⁇ are variable parameters.
• Respective values of the parameters ⁇ and ⁇ at the instant n are selected by the module 46 as a function of the value at the instant n of the difference C ap C ns [ n ] ⁇ C ap nat is M -
• the parameters ⁇ and ⁇ are for example tabulated in the module 46 according to the values of this difference Alternatively, the parameters ⁇ and ⁇ are constant.
• the component Y av has the effect of attenuating the temporal variations of the torque setpoint delivered to the GMP 12 just before crossing a transmission set.
• the time derivative of the torque set CAP C ns agr delivered to the GMP is lower in absolute value than the time derivative of the torque set point C A p C ns delivered by the module 40, and preferably this time derivative CAP C ns agr ⁇ St substantially zero during the passage of these games.
• the component Y ap has the effect of further, and quickly converge to the CAP C ns desired torque desired by the driver of the vehicle once the game transmission past.
• FIG. 3 is a graph illustrating the preventive authorization instruction obtained by the system according to the invention (curve A), that obtained by a system of the state of the art (curve B), the desired torque set by the driver (curve C) and a real value of a passing torque of a transmission set (curve D).
• curve A the preventive authorization instruction obtained by the system according to the invention
• curve B the desired torque set by the driver
• curve D a real value of a passing torque of a transmission set
• the torque setpoint calculated by the system according to the invention takes effect at the level of the game's passing torque, unlike that of the state of the art, while being regular, c that is, without presenting the discontinuities of that of the state of the art.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37605791

Family Applications (1)

Country Status (3)

Families Citing this family (5)

Family Cites Families (4)

• 2006
  • 2006-04-04 FR FR0651185A patent/FR2899282B1/fr not_active Expired - Fee Related
• 2007
  • 2007-03-28 EP EP07731839A patent/EP2002102A1/de not_active Withdrawn
  • 2007-03-28 WO PCT/FR2007/051033 patent/WO2007116168A1/fr not_active Ceased

Non-Patent Citations (1)

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