FR2750734A1 - METHOD AND DEVICE FOR CONTROLLING THE INJECTED QUANTITY OF FUEL FITTED TO THE CYLINDERS OF AN INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

Means incorporated in an injection system prevent jerks in operation in the form of rapid variations in rotational speed or relative movements of the engine on the vehicle. The means comprise, coordinated with sensors for the position of the accelerator pedal (1) and the speed of rotation (n) of the engine, a control device (5) with circuits for establishing a speed of variation of the speed of rotation and calculate a correction of the quantity of fuel injected taking into account a characteristic diagram of quantities stored in the control unit (5) and various other parameters (PL, TK, TL) of engine operation, as well as 'a converter (6) receiving at its input a weighted correction value (me) and the output of which is connected to an injection device (7). Applicable to fuel injection in automobile engines.

Description

The invention relates to a method for regulating the injected amount of

  fuel supplied to the cylinders of an internal combustion engine and a device for

the implementation of this method.

  DE 37 21 300 AI discloses a system which acts on a control device of a fuel injection pump. In this system, a fuel flow control member, which is operable by a control device and control of the amount of fuel

  fuel in a manner that depends on operational parameters

  of the internal combustion engine, is maneuvering

  additionally by an actuating member

  even by an anti-jerk signal generated according to

  the appearance of rapid changes in the rotational speed

  tion or relative movements of the internal combustion engine

  dull on the vehicle, designated by

  ment, a signal that opposes such jerks by

  ganes acting on the fuel flow. A lever of

  setting, coupled to the fuel flow control

  rant, can rotate between two stops defining a

  basic glare. In a control device to which

  at least the rotational speed of the engine to

  internal bustion, are generated, by means of an algorithm,

  so-called anti-jerk signals that are sent to a

  step-by-step. It turns to a fixed number of

  not per unit of time and thus moves the stops, defining

  setting range for the adjustment lever.

  This known system is only suitable for mechanical injection systems, the adjustment lever being urged on the one hand by a spring engaging the

  lever and on the other hand by a rotational speed sensor

  centrifugal type. The control unit can not

  not directly influence the position of the

  setting, but only serves to change the position of the stops, that is to say to produce a change of the adjustment range. For modern injection systems with controlled valves whose switching speed is frequently less than 1 millisecond, this known system is not suitable because of the inertia of the acting masses and it is to set in motion. The object of the invention is to create a method

  to regulate the quantity injected (to be injected) of the fuel

  brought to the cylinders of an internal combustion engine

  dull, by which the movements of the accelerator pedal

  can be converted as quickly as possible

  in a correction of the amount of fuel

  jected and a corresponding control signal can be

  sent to a device producing the fuel injection

  rant. The invention also aims to indicate a device

  for the implementation of this method.

  With regard to the method, this result is obtained by the fact that it comprises the following process steps: a) as a function of the change of position of a pedal

  accelerator, a sensor signal is generated.

  (b) the pedal position sensor signal is sent to a control apparatus into which at least the current rotational speed of the engine is introduced.

  internal combustion as an input

plementary,

  (c) from the value of the speed of rotation

  it is determined, by differentiation, a speed of variation of the speed of rotation, d) as a function of the change of the pedal position sensor signal and the speed of variation of the speed of rotation, it is calculated in the apparatus of

  controls the value of an in-

  jected, with negative amplification of the value of the correction of quantity injected in a range close to the full charge and positive amplification in a range close to the zero charge, e) transforming the correction of quantity injected by multiplication by a weighting factor rotational speed to a weighted injected quantity correction and f) the weighted injected quantity correction is sent to a converter which, as a function of the weighted injected quantity correction, generates control signals which are transmitted to a device producing

fuel injection.

  As for the device, we get

  the result sought by the fact that it includes a

  command, a pedal position sensor that

  is connected to the control unit and sends him a

  pedal position indication according to the actuation

  of an accelerator pedal, a speed sensor of speed

  to detect the current rotation speed of the motor, which sensor is also connected to the

  command, means for establishing a speed of variation

  rotational speed, as well as means for calculating a quantity correction injected taking into account a quantity characteristic diagram stored in the control apparatus, a device, provided for in FIG.

  following these means, to weight the value of the cor-

  quantity injected, as well as a converter

  which receives at its input the correction of

  weighted tee and is connected by its output to a device

  producing fuel injection.

  The essential advantages provided by the invention

  The reason is that an extremely poor exploitation

  the speed of rotation and the pedal position signal take place and that, in this operation, account is taken of the fact that the speed of rotation is in a range close to full load or in a range close to the zero charge. By this arrangement, as well as the incorporation of a rotation speed weighting factor, the oscillations represented by the aforementioned operating jolts can be reliably avoided. It is advisable to incorporate, in the determination of the value of the injection quantity correction, the ratio or the speed used at this moment of the vehicle gearbox. For this reason, the rate of change of the speed of rotation should be established by means of a band-pass filter whose action depends on the gear ratios or speeds of a vehicle gearbox. It is also advantageous to store in the control apparatus, or to send to this apparatus, data specific to the type of vehicle, a so-called vehicle model. In this way, the calculation of a value of variation of the speed of rotation is made according to typical parameters for the vehicle, so that, for example, mass inertia, important for acceleration processes or deceleration, is

incorporated in the regulation.

  A value of the desired torque is calculated, taking into account the signal provided by the pedal position sensor and the current rotation speed, in a

  a characteristic diagram of the step stored in the

  control order. From this value can be set

  bli, taking into account other parameters, a torque load ratio, namely the desired torque or setpoint / maximum torque ratio (Mco / Mmax) the maximum torque

  depending in particular on the X value.

  of the control device, the maximum torque can therefore be determined each time according to determined parameters, so as to obtain, for example, a limitation of the exhaust fumes, so that at a given operating point, only a determined quantity of fuel is released, regardless of the possible demand for a larger quantity of fuel by the position occupied by the accelerator pedal at that moment.

  Other features and advantages of the

  will become clearer from the description

  which will follow from an example of non-limita-

  as well as the attached drawings, in which:

  FIG. 1 is a diagrammatic representation

  of a device for controlling the quantity of car-

  injected fuel according to the position of the accelerator pedal;

  FIG. 2 represents a system for generating

  derive an injected quantity correction signal; and - Figure 3 shows a system for generating a specific rotational speed variation value

to the vehicle.

  Figure 1 schematically represents a dis-

  positive to control the amount of fuel injected

  depending on the position of the accelerator pedal.

  A control apparatus 5 serves to generate a signal for controlling the injected quantity, or for a value

  corresponding variation, depending on several

  introduced into the control unit. The posi-

  accelerator pedal 1, tilting

  a chassis 2, is of particular importance

  in this respect. This position of the accelerator pedal

  The controller is sent to the control device 5 as a UFp voltage, provided that a change of position

  of this pedal causes a variation of the voltage UFp.

  At the control unit 5 is also sent the

  current rotation speed n, determined by a sensor

rotation speed 26.

  As additional input quantities

  In the control unit 5, for example, the boost pressure PL, the coolant temperature TK and the boost air temperature TL can be used. The output signal, calculated in the control apparatus 5 from the input parameters, corresponds to the change in the amount of injection required due to the change of the position of the accelerator pedal and is designated by me. This signal is sent to a converter 6 whose output signal, in the form of a current I, serves to control an injector 7. The latter may be part of, for example, a feed pipe injection system.

  common or common-rail.

  Figure 2 shows that the accelerator pedal 1,

  reclining on the chassis, acts through the

  a coupling device 3 on a pedal position sensor 4 which, in the example shown here, is in the form of a variable resistor. Instead of this resistance, it is also possible to use a Hall effect generator or an inductive sensor. By means of this pedal position sensor 4, the voltage U is changed according to the position of the pedal, or the change of position of the accelerator pedal 1, and sent as a voltage UFp to the control unit As shown in FIG. 2, this apparatus comprises, to begin with, an operating characteristic diagram 8 with a family of parameter curves stored in this apparatus. In addition to the voltage UFp provided by the pedal position sensor 4, the control unit receives the instantaneous rotation speed n. With the help of the diagram 8 and taking into account the signal UFp and the speed n, is calculated a

value of the desired Mco torque.

  According to the exemplary embodiment shown in FIG. 2, the further calculation in the control device must be based on the desired torque, represented by the actuation of the accelerator pedal. For this reason, the value of the desired torque or setpoint Mco is sent from the operating characteristic diagram 8 to a characteristic pattern of pressures 9 provided below. In the pressure characteristic diagram 9, as an additional parameter, the boost pressure PL is added, so that, on the basis of the torque characteristics contained in the pressure characteristic diagram, as a function of the value of the instantaneous supercharging pressure. , the injector 7 - see Figure 1 - finally injects

  also a limited amount of fuel.

  The characteristic pressure diagram 9 thus acts as a limitation of the exhaust fumes. The signal M1 obtained at the output of the pressure characteristic diagram 9, corresponds to the quotient of the desired torque or setpoint Mco and the maximum torque Mmax, the last

  being determined from the value k of the characteristic diagram

  9. From the setpoint torque Mco is therefore formed, taking into account other parameters,

the load ratio Mco / Mmax.

  The control apparatus 5 shown in FIG. 1 contains, according to the representation of FIG. 2, what is called a vehicle model 10, in which are

  stored the vehicle-specific values for a cal-

  suitable for the type of vehicle concerned. From the

  torque M1 and the speed of rotation n of the engine to com-

  internal bustion is calculated using the model

  of vehicle 10, an acceleration corresponding to a

  their intended for the variation of the rotational speed

  Noh. This expected value at, calculated in the model of

  number 10, is sent to a summation element 11

  what is further applied the variation of the speed of

  rotation A, established by a different transfer element

  delay transmitter or element DT1. The difference between the value predicted for the variation of the speed of rotation and the variation of the speed of rotation A is sent to a quantity characteristic diagram 13, in which is also introduced, as a quantity

additional, the couple Ml.

  The family of parameter curves in the quantity characteristic diagram 13 is arranged from

  a value for the quantity correction

  Ame is calculated as a function of the torque value M1 determined by the change of position of the accelerator pedal, as well as the value provided for

  the variation of the speed of rotation n and the variation

  the speed of rotation A. In order to avoid

  regulation problems that could occur near the full load or the zero load (when the accelerator pedal 1 is released), the injected quantity correction signal Ame, which signal is derived from the quantity characteristic diagram 13, is sent to a multiplier element 14 which is further brought the value of the average rotational speed T, established using a band-pass filter 15. In the multiplier element 14, therefore, a weighting of the speed of variation of the speed of rotation by the ratio of load and the speed of rotation. The value thus ultimately established is the quantity correction injected

weighted me-

  Figure 3 shows a system for generating or establishing a vehicle-specific variation value of

  the speed of rotation. This requires, as signals of

  the torque M1 and the current speed n.

  The torque M1 is sent to an injected quantity correction unit 25 which essentially comprises the quantity characteristic diagram 13 and the element

  multiplier 14 of the system shown in FIG.

  The value of the torque M1 is also applied to an element

  16. The current rotation speed is first sent through a bandpass filter 21 to a delay differentiator transfer element or element DT1 22. The bandpass filter 21 is designed to after the transmission ratios of the gearbox speeds. The output signal of the element DT1 22 is the variation of the rotation speed A, which

  is applied to an element PT1 20. The variation of the

  rotation A is also applied to an element

  of warning 18 to which the

  the value of the speed variation

of rotation n.

  In element PT1 20, is formed, taking

  the ratio (speed) of the gearbox used

  at this time for the propulsion of the vehicle, a

  which is sent to a summation element 19. To this element is further applied the value provided for the variation of the speed of rotation n, which value

  is deducted from the output value developed in the

  PT1 20. The result obtained in the summary element

  19. is converted into an integrator 24 into a variable

  their pair which corresponds to the quotient AM: Mmax. The torque value expressed. by this quotient, is deducted,

  in the summation element 16, the desired torque M1,

  also referred to the summation element i6, and the result

  tat is sent to a PT1 element 17. In the latter is formed, from the torque value, the value provided for the variation of the rotation speed δ, a value which, as already mentioned above, is applied to

  summation element 18. The latter therefore forms a difference

  Anence which corresponds to the subtraction n minus n.

  The value (speed) of variation of the speed of rotation, established in this way, is sent to

  the quantity correction unit 25 injected and, in

  the torque value M1 applied to this unit, converted into a characteristic diagram of

  quantities in a value of the quantity correction

  jected Ame. A PT1 element 23 forms, from the

  current rotation speed n, rotational speed

  mean n, which is sent to the correction unit 25

  quantity injected. In this unit 25,

  kills a weighting of the speed of variation of the

  rotational speed, which means that the value of the injected quantity correction Ame is multiplied by the rotational speed weighting factor, so that in the end there is a correction of

injected quantity weighted me.

Claims (10)

  A method for regulating the injected amount of the fuel fed to the cylinders of an internal combustion engine, characterized in that it comprises the following process steps: a) as a function of the change of position of an accelerator pedal ( 1), a pedal position sensor signal (UFp) is generated, b) the pedal position sensor (UFp) signal is sent to a control apparatus (5) into which at least the rotational speed is introduced. current   (n) of the internal combustion engine as a large additional input   (c) from the value of the speed of rotation   it (n), one determines, by differentiation, a vi-   speed of variation of rotation speed (A), d) as a function of the change of the sensor signal of   pedal position (UFp) and the speed of varia-   the rotational speed (A), the value of a correction is calculated in the control device (5).   of injected quantity (Ame), with negative amplification   the value of the injection quantity correction   (Ame) in a range close to the full load and positive amplification in a range close to the zero load, e) transforming the injection quantity correction.   (Soul) by multiplying by a weighting factor   rotational speed in a weighted injected quantity correction (me) and f) the weighted injected quantity correction (me) is sent to a converter (6) which, depending on the weighted injected quantity correction (me), generates control signals (I) which are transmitted to a   device (7) producing fuel injection.   2. Method according to claim 1, characterized   rised by generating the rate of change of the rotational speed (>) using a bandpass filter   (21) whose action depends on the ratios (speeds)   of the vehicle gearbox, as well as a delay differentiator transfer element or DT1 element (22).   3. Method according to claim 1 or 2,   characterized in that it is stored in the control apparatus   (5), where specific data can be sent to this   the type of vehicle (vehicle model), and the   calculation of an expected value for the variation of the   rotation speed (<) depends on the model of vehicle (10).   4. Process according to claim 3, characterized   rised by reducing the expected value for the vari-   rotation speed (<), generated in the model   of the vehicle (10), the value of the speed of   rotation speed (A).   5. Method according to one of the preceding claims   dentes, characterized in that a value of   desired torque or setpoint (Mco) in a diagram   operating characteristic (8) taking into account the pedal position sensor (UFp) signal and the speed of current rotation (n).   6. Process according to claim 5, characterized   in that, from the desired torque (Mco), a load ratio between the desired torque and the maximum torque is formed taking into account other parameters. (Mmax) -   7. Device for regulating the injected quantity of the fuel fed to the cylinders of an internal combustion engine, characterized in that it comprises a control apparatus (5), a pedal position sensor (4) which is connected to the control unit (5) and sends him a   Pedal position signal (UFp) according to the ac-   of an accelerator pedal (1), a sensor of   rotation speed (26) for detecting the speed of rotation   current (n) of the motor, which sensor is also connected to the control device (5), means (12; 21, 22) for setting a speed of variation of the rotation speed (e), as well as means (13, 25) for calculating an injected quantity correction (Ame) taking into account a quantity characteristic diagram (13) stored in the control apparatus, a device (14),   following these means (13), to weight the   their injected quantity correction (Ame), as well as   a converter (6) which receives at its input the cor-   weighted injected quantity rection (me) and is connected by its output to a device (7) producing the injection fuel.   8. Device according to claim 7, characterized   characterized in that the control apparatus (5) comprises a vehicle model (10; 16, 17, 19, 20, 24)   according to vehicle-specific data and in the   which account is taken, in particular, of the report of   transmission of gearbox speeds.   9. Device according to claim 7 or 8, characterized in that the means for generating the speed of variation of the speed of rotation (A) comprise a band-pass filter (21) and a transfer element.   delay differentiator (element DT1 22).   10. Device according to one of claims 7 to   9, characterized in that the control device (5) comprises   takes a characteristic walk diagram (8) as well   a characteristic diagram of pressures (9).