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
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
• • 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
  • F02D41/12—Introducing corrections for particular operating conditions for deceleration
  • F02D41/123—Introducing corrections for particular operating conditions for deceleration the fuel injection being cut-off
  • F02D41/126—Introducing corrections for particular operating conditions for deceleration the fuel injection being cut-off transitional corrections at the end of the cut-off period
• • 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
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
  • F02D2041/1413—Controller structures or design
  • F02D2041/1418—Several control loops, either as alternatives or simultaneous

Definitions

• the present invention relates to a method and a device for regulating the operation of a torque-controlled internal combustion engine, when this engine returns to idle speed. More particularly, the invention relates to such a method and to a device associated with an internal combustion engine propelling a motor vehicle.
• the operation of the engine 2 is commonly managed by a digital electronic computer 3 which receives signals from various groups of sensors 4,5 sensitive to parameters affecting the operation engine (intake pressure, engine speed, cooling water temperature, activation of an air conditioner or assistance for steering the vehicle, etc.).
• the computer 1 is duly programmed to develop, from signals supplied by the groups of sensors 4.5, control signals from the various actuators 6 acting on the engine, fuel miectors, spark plugs of the air / fuel mixture, etc. ..., so that the engine delivers a torque corresponding to that requested by the driver.
• a position sensor of an accelerator pedal of the vehicle delivers to the computer 3 a signal representative of this torque request.
• Computers are known which are also equipped with a torque regulator. Such a torque regulator makes it possible, for example, to take into account the rise of a slope by the vehicle, the activation of torque consumers such as a power steering or an air conditioner, etc.
• the computer can commonly act, in addition to the opening time of the fuel collectors and the angle of advance at ignition of the air / fuel mixture, on the opening angle of the throttle valve, this throttle valve is then "motorized", and on other possible additional means making it possible to act on the quantity of air entering the engine, in particular in idle speed.
• This strategy essentially comprises two phases, a phase of return to idling during which the rotation speed N of the engine drops from the value reached at the time of foot lift to an idle setpoint value N cons , then a phase regulating the speed of this engine around this value N cons , despite variations in engine load or temperature for example, or random disturbances affecting the operation of this engine (misfires, for example).
• Patent EP 0 694 121 (Siemens Automotive SA) describes a method for controlling an internal combustion engine when entering idle speed, the engine being associated with means for controlling its speed to a value of predetermined setpoint. Upon detection of an operating state of the engine calling for entry into idle speed, a decrease in the engine set point speed is controlled according to a predetermined time law, covering both the phase of return to idle speed and the speed idle proper.
• the object of the present invention is to provide a method for regulating the operation of an internal combustion engine, when returning to idle speed, which does not have any of the drawbacks of the methods described above and which is well suited to a torque-controlled motor.
• the present invention also aims to provide such a method which ensures the phase of return to idle speed and the regulation phase of this speed without it being necessary to distinguish these two phases during engine operation.
• Another object of the present invention is to provide a device for implementing this method.
• a method of regulating the operation of an internal combustion engine controlled in torque, during a return to idle speed comprising the following steps: a) it is determined whether a state calling for a return to the idle speed is present, b) if so, a current torque setpoint is determined from a setpoint value for said idle speed and an estimate of the resistive torque applied to the engine, so as to continuously regulate the engine speed when returning to idle speed and during the subsequent idle speed, and c) the torque delivered by the motor from said current torque setpoint.
• the current torque setpoint is determined by choosing for it a value which causes the variable quantity ⁇ defined by the expression to converge to zero:
• - N and z ⁇ N are the values of the engine speed measured, respectively, at the current sampling instant and the previous sampling instant, - ffrr is a positive coefficient bounded by a threshold function of the estimated resistive torque C res , of the current speed N and of the reference speed N cons .
• the regulation of the engine through the quantity ⁇ makes it possible to merge the return to idling and the regulation of idling with all the flexibility required, this regulation being perfectly suited to a torque-controlled motor.
• the invention provides a device comprising a) means for detecting the appearance of a state calling for a return to idle speed, b) means for then determining a set value for this regime, c) means for estimating the resistive torque then applied to the engine, d) means for calculating a current reference value for the torque which the engine must deliver, from said current regime reference value of idling and of said resistive torque, to continuously bring the engine speed to said setpoint and regulate it, and e) means for regulating the engine torque to said current setpoint.
• - Figure 1 shows the architecture of the regulation device according to the invention, already partially described in the preamble to this description
• - Figure 2 is a flow diagram of a program for implementing the regulation method according to invention.
• the computer 3 of the device according to the invention essentially comprises an estimator 7 of the resisting torque C res applied to the engine 2, a speed regulator 8 characteristic of the present invention and comprising , as will be seen below, means for calculating a current setpoint value C cons for the torque which the motor 2 must deliver, from a current setpoint N cons of the idle speed and the resistive torque C re3 estimated by the estimator 1, and a regulator 9 of the engine torque at the current setpoint C COns / this latter regulator being known in itself, all like the estimator 7.
• the measurement signals delivered by the groups of sensors 4 and 5 are selectively delivered to the torque estimator 7, to the speed regulator 8 and to the torque regulator 9 according to the known needs of the estimator 7 and of the regulator 9. As regards the regulator 8, the signals received will be specified below.
• a sensor for depressing the accelerator pedal (not shown) and a sensor sensitive to the arrival of said pedal in the "raised foot" position. It is this latter sensor which signals to the computer 3 that the vehicle is in a state calling for a return to idling speed.
• Other optional conditions can be posed to trigger such a return such as, for example, the passage of the speed of rotation of the motor below a threshold.
• the torque estimator 7 is constituted by software stored in the computer 3.
• the software inputs are digital measurement values supplied by sensors of groups 4 and 5, allowing this software to calculate or evaluate the various resistant couples, the sum of which opposes the torque delivered by the engine 2.
• These resistant couples are essentially those consumed in the engine, in particular by friction, and by accessories of the energy-consuming vehicle such as an alternator, a air conditioner compressor, steering pump assisted, etc.
• the resistive torque C res thus calculated is supplied to the speed regulator 8.
• the speed regulator 8 comprises means for determining a reference speed value N id s of idling, a function of one or more engine operating parameters such as, for example, the engine water temperature, the operating condition of the air conditioner, the operating status of the power steering, etc. This value is taken from a "map" of N cons whose inputs are constituted by these parameters, said map being recorded in the memory of the calculator 3.
• the speed regulator 8 also comprises software means designed to calculate, from the speed N of the engine, the idle speed setpoint N cons and the resistive torque C res supplied by the estimator 7, the value C c o ns of the current torque setpoint that the engine must supply to correct the variations in speed so that they cause the speed value N of the engine to converge to the idle setpoint N cons .
• the calculation program is executed cyclically as soon as an entry into idle speed is triggered by a signal from the "foot raised" position sensor of the accelerator pedal, and by any other optional signals, as shown. saw above.
• step 100 the speed regulator 8 receives the values of the operating parameters of the engine 2 supplied by the groups of sensors 4,5, in particular the speed value N of this engine, and the value of the resistive torque C res calculated by the estimator 7.
• step 110 the speed regulator 8 draws from a map the value of the idle speed setpoint N cons , as seen above.
• step 120 the regulator 8 calculates a coefficient ffrr chosen so as to respect the following relation:
• ffdyn is a constant function of the characteristics of the engine.
• the regulator calculates, in step 140, the value of the torque setpoint C COn s to be transmitted to the torque regulator 9, which converges ⁇ towards zero.
• step 150 the current measured value of the speed N is stored, where it replaces the previous value z N.
• the torque setpoint C con s is finally addressed, in step 160, to the torque regulator 9 which regulates engine 2 both when the engine is running in idle speed and in normal speed.
• This regulator can also, for this purpose, receive torque instructions from other devices, outside of the return to idle or subsequent idle speed.
• the calculation of the setpoint value C cons gui causes ⁇ to converge to zero can be performed using one of several regulation algorithms well known to those skilled in the art.
• variable ⁇ comprises a first term (N 2 - z — 1N2) which gives rise to two successive samples z N and N of the speed, or speed, of the engine, this term being therefore sensitive to the current variation of this

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9527272

Family Applications (1)

Country Status (3)

Family Cites Families (7)

• 1998
  • 1998-06-11 FR FR9807367A patent/FR2779768B1/fr not_active Expired - Fee Related
• 1999
  • 1999-06-11 WO PCT/FR1999/001384 patent/WO1999064738A1/fr not_active Application Discontinuation
  • 1999-06-11 EP EP99923719A patent/EP1086306A1/de not_active Withdrawn

Non-Patent Citations (1)

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