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
  • F02D41/042—Introducing corrections for particular operating conditions for stopping the engine
• • 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
  • F02D41/0097—Electrical control of supply of combustible mixture or its constituents using means for generating speed signals
• • 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
  • F02D2200/1012—Engine speed gradient
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N11/00—Starting of engines by means of electric motors
  • F02N11/08—Circuits or control means specially adapted for starting of engines
  • F02N11/0851—Circuits or control means specially adapted for starting of engines characterised by means for controlling the engagement or disengagement between engine and starter, e.g. meshing of pinion and engine gear
  • F02N11/0855—Circuits or control means specially adapted for starting of engines characterised by means for controlling the engagement or disengagement between engine and starter, e.g. meshing of pinion and engine gear during engine shutdown or after engine stop before start command, e.g. pre-engagement of pinion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N19/00—Starting aids for combustion engines, not otherwise provided for
  • F02N19/005—Aiding engine start by starting from a predetermined position, e.g. pre-positioning or reverse rotation
  • F02N2019/008—Aiding engine start by starting from a predetermined position, e.g. pre-positioning or reverse rotation the engine being stopped in a particular position
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N2200/00—Parameters used for control of starting apparatus
  • F02N2200/02—Parameters used for control of starting apparatus said parameters being related to the engine
  • F02N2200/022—Engine speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N2300/00—Control related aspects of engine starting
  • F02N2300/20—Control related aspects of engine starting characterised by the control method
  • F02N2300/2006—Control related aspects of engine starting characterised by the control method using prediction of future conditions

Definitions

• the present invention relates to the field of internal combustion engines, and more particularly to the anticipated determination of the rotational speed in the stopping phase of the engine.
• the electronic computers mainly have information provided by two sensors, which respectively characterize the rotation of the crankshaft of the engine (it is called a speed sensor), and potentially the rotation of at least one camshaft (this is called a position sensor AAC or camshaft).
• the crankshaft performs 2 turns, a rotation of 720 °.
• a cycle starts at 0 ° crankshaft angle at the beginning of a compression phase of a given cylinder and ends at 720 ° at the end of the intake phase of this same cylinder.
• the flywheel secured to the crankshaft of the engine, is provided on its periphery with a set of teeth, called target, opposite which is positioned the speed sensor. It delivers an alternating voltage in crenels, presenting rising electric fronts and descending electric fronts, and whose frequency varies with the engine speed.
• the flywheel may have, for example, 58 teeth and two gaps (that is to say, a toothing of 60 teeth including 2 missing). The sensor will detect these gaps thus providing information on the position of the crankshaft and the speed of rotation or engine speed.
• the invention aims to solve one or more of these disadvantages.
• the invention thus relates to a method for predicting the rotational speed of an internal combustion engine crankshaft in an end-of-rotation phase, characterized in that:
• the actual rotational speed of the crankshaft is determined and recorded at angular positions of said crankshaft for a range of angular positions of the crankshaft delimited by a first angular position and a second angular position corresponding to angular periodic oscillations of decreasing the speed of the crankshaft. rotation of the crankshaft.
• a constant is determined as a function of the difference of squares of the real regimes determined for the first and second angular positions
• a predicted crankshaft rotation speed is determined for a third angular position of the crankshaft, not included in the range of angular positions of the crankshaft, as a function of the constant and the actual speed determined at a fourth angular position included in said range and such that the difference between the third and fourth angular positions is equal to or is a multiple of said range.
• the invention may include one or more of the following features:
• the second angular position corresponds to the position at the present moment of the crankshaft which is the last angular position for which one can determine a real regime.
• the range of angular positions of the crankshaft is advantageously 180 °, 360 ° or 720 ° which corresponds to respectively to a motor phase, a motor revolution, a motor cycle.
• the range is representative of the periodicity of the loss couples of the phases of admission, compression, expansion and exhaust of the engine and the phase shift of the cylinders.
• the range of angular positions of the crankshaft is 360 ° to have a better precision of the prediction of the regime.
• the range is 240 ° or 720 °, because of the phase shift of the cylinders - In a variant where the engine comprises six cylinders, the range is 120 °, 240 ° or 720 °, because of the phase shift of the cylinders.
• crankshaft being rotatably connected to a toothed wheel comprising teeth for determining the angular position of said crankshaft, the angular width between each tooth being 6 °, the predicted crankshaft rotation speed for the third angular position of the crankshaft is determined according to the actual regime by applying the following relation:
• a and B are variables such as:
• n is the index of the tooth locating the second angular position of the crankshaft
• n + d is the index of the tooth identifying the third angular position of the crankshaft
• n - + B is the index of the tooth identifying the fourth angular position of the crankshaft
• the method further comprises the following steps:
• the predicted diet is determined for the tooth of index n + 1,
• a predicted regime is determined for the fixed time, by interpolation between the predicted regimes for the last two indices.
• the invention also relates to an application of the method of the invention to the prediction of the stopping cylinder of an internal combustion engine, characterized in that the third angular position of the crankshaft corresponds to a top dead center. combustion.
• the estimation of the speed for angular positions of the crankshaft corresponding to a top dead center, also called PMH combustion, makes it possible to determine the last PMH for which the estimated speed will be non-zero and to deduce the cylinder in corresponding compression that is designated as the stop cylinder.
• FIG. 1 is a schematic representation of an internal combustion engine 1.
• FIG. 2 is a diagram showing the end of rotation phase of the crankshaft.
• FIG. 3 illustrates the procedure of predicting the engine speed on a fixed angle.
• FIG. 4 illustrates the procedure of predicting the engine speed over a fixed time.
• FIG. 5 illustrates the procedure for predicting the stop cylinder.
• FIG. 1 schematically shows an internal combustion engine 1 comprising a crankshaft 2.
• the internal combustion engine is equipped with a device 3 for determining the rotational position of the crankshaft 2.
• This device comprises a toothed wheel 4, a sensor 5 of regime connected to an electronic control unit 6 also called ECU.
• the toothed wheel 4 is integrally connected in rotation to the crankshaft 2 so that when the internal combustion engine 1 operates, the toothed wheel 4 rotates relative to the to the engine 1.
• the periphery of the toothed wheel 4 comprises teeth 7 corresponding to an angular width of 3 ° and two teeth are separated by a recess 8 with an angular width of 3 °. In one part of the periphery, two adjacent teeth 7 have been removed to have an enlarged tooth gap called spacing 9. At each passage between a tooth 7 and a recess 8 or at the spacing 9, there is a tooth flank 10
• the ECU 6 comprises the calculation and storage means necessary for determining the actual engine speed and the predicted engine speed according to the
• t id the time separating two successive identical fronts.
• the fronts can be 12 or downs 13.
• a so-called instantaneous or real N regime expressed in degree / second can then be estimated by the following relation:
• the sensor 5 is a Hall effect sensor mounted in a fixed manner with respect to the internal combustion engine 1.
• the sensor 5 captures the succession of teeth 7 and tooth gaps 8 or the spacing 9 which passes in front of it and generates a crenelelectric signal January 1, having rising electrical fronts 12 and descending electric fronts 13, whose Frequency varies with the N rotation speed of the motor.
• the engine speed can be predicted using information based on the difference between a current instantaneous squared regime and the engine speeds. snapshot prior to squared.
• end of rotation phase is understood to mean the period following a stopping of the operation of the internal combustion engine 1 due to a cut by the ECU 6 of the injection and ignition.
• FIG. 2 shows the end-of-rotation phase of the crankshaft 2 of the internal combustion engine 1 in the form of a diagram giving the variation of the speed N as a function of the angle ⁇ of the crankshaft 2.
• FIG. the end phase rotation speed N of the crankshaft 2 decreases. Indeed, the internal combustion engine 1 does not provide energy and loss of torque due to the friction forces, but not only, oppose the rotation of the crankshaft 2 of the engine 1 and slow the speed of rotation N Crankshaft 2.
• Figure 2 further shows that the decrease in the speed of rotation N of the crankshaft is not monotonous but presents oscillations periodically angularly, in other words on a range T of angular positions. Indeed, these oscillations are due to the fact that certain loss pairs such as those generated by the efforts of admission, compression, expansion and exhaust which are periodic phase shift between the engine cycles of each cylinder of the engine.
• the range T of angular positions of the crankshaft 2 is 180 °, 360 ° or 720 °.
• the range T is 360 °, to have a better precision of the prediction of the regime.
• the procedure for predicting an engine speed at a given angle of the crankshaft 2, in other words for a given number of teeth d of the toothed wheel 4 is as follows: the actual rotational speed of the crankshaft is determined and recorded at angular positions said crankshaft for a range T of angular positions of the crankshaft 2 delimited by a first angular position and a second angular position.
• a recording of the inter-tooth durations, t id for the period T considered, the number of records is in our example, the last thirty inter-tooth durations, t id, or a record on a range of 180 °.
• the second angular position corresponds to the position at the present moment of the crankshaft 2.
• FIG. 3 shows in full line the recorded angular period T and indicates in dashed line the variation of the rotational speed to come.
• the real rotational speed is determined by the relation (1).
• the actual speed values are stored in the ECU 6 for their future use in the rest of the procedure.
• the constant C 0 is determined as a function of the difference of squares of the real regimes determined for the first and second angular positions, in other words by the difference between the instantaneous squared regime of the first recording and the instantaneous squared regime of the last recording. .
• a predicted N rotation of the crankshaft 2 is determined for a third angular position of the crankshaft 2, not included in the range T of angular positions of the crankshaft 2, as a function of the constant C 0 and the real speed N determined at a fourth angular position in said range T and such that the difference between the third and fourth angular positions is a multiple greater than or equal to said range (T).
• the predicted diet N is determined on the basis of a general formula whose expression is now demonstrated: For the purposes of the demonstration and as illustrated in FIG. 3, the last record is assigned the index n. The first record therefore has the index (nT / 6).
• N 2 , - N 2 + 20 C 0 (13) n + 20
• the value of a time counter S is initialized to 0 for the tooth of index n.
• an inter-tooth time, t id corresponding from the relation (1), referenced t n + i, is calculated in FIG. 4, - it is incremented the time counter S of the inter-tooth time calculated.
• a predicted regime is determined for the fixed time tp, by interpolation between the predicted speeds for the last two indices, referenced respectively N N + 2 - N N + 3 in the figure
• Stop cylinder means the cylinder which is in the compression phase of the engine cycle.
• N PM H the actual top dead center (or TDC) combustion regime
• the invention is not limited to a particular type of combustion engine.
• the range T of angular positions of the crankshaft 2 is preferably 240 ° or 720 °, due to the phase shift of the engine cycles of the various cylinders.
• the range T of angular positions of the crankshaft 2 is preferably 120 °, 240 ° or 720 °, due to the phase shift of the engine cycles of the various cylinders.
• the invention has the advantage of being simple to set up as a computer routine programmed in the ECU and does not require any particular calibration.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42122883

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (2)

Citations (10)

Family Cites Families (5)

• 2009
  • 2009-09-23 FR FR0956536A patent/FR2950388B1/fr not_active Expired - Fee Related
• 2010
  • 2010-08-19 WO PCT/FR2010/051734 patent/WO2011036361A1/fr active Application Filing
  • 2010-08-19 CN CN201080042553.3A patent/CN102510941B/zh not_active Expired - Fee Related
  • 2010-08-19 EP EP10763213.5A patent/EP2480776B1/fr active Active
  • 2010-08-19 BR BR112012005586-0A patent/BR112012005586B1/pt not_active IP Right Cessation

Patent Citations (10)

Also Published As

Similar Documents

Legal Events