FR2624967A1 - METHOD FOR TARING POSITION RETROSIGNAL VALUE - Google Patents

Abstract

Such processes are used, for example, for carburettors of internal combustion machines, in combination with electronic control. A problem then is that the throttle position feedback signal has individual dispersions from one carburetor to another. This is why it is provided for carburettors adjusted according to steps a) to d), that for the consecutive operation, an association of the value of the alpha position feedback signal at each position of the adjustment element and respectively at each value of the position feedback S only intervenes after calibration to an alpha 'value determined by a characteristic Ku, by adding an alphaT calibration value so that alpha' is increased at least up to the value of the characteristic Ku. More precise association of the signal values results in better engine operation and provides an indication of whether or not a tuning element or engine operator is operating the throttle.

Description

Method for setting a positional retrosignal value The invention

  relates to a method for setting a position feedback value of a control element

  adjustable by an adjusting element in combination with a

  interpretation system, for which a) the adjustment element is brought to a position defined by a position feedback value (SE) of the predetermined adjustment element, b) to the adjustment element brought into this position , the element

  control is mechanically associated with a range of

  predetermined value of a control quantity, c) the value of the position feedback signal (a) of the control element is detected and d) transmitted, together with the value (S) of the control signal.

  the adjustment element, to the interpretation device.

  A device for implementing such a method

  is already indicated in the form of the Bosch Corporation, Techni-

  Unterrichtung - Motor-Elektronik, VDI-V 1/1 DE (7.83), page 33. This is a carburettor whose throttle is moved more or less in the "open" direction by means of an of butterfly adjustment in the measure o said butterfly

  is not arbitrarily opened by an engine operator.

  The throttle adjustment member is then controlled by a

  the output of an electronic control device which

  receive signals from an idle switch, a potential

  throttle position meter and repeater potentiometer

  position of the throttle adjustment member and

  other values of the operating parameters of the

  tor. When setting this carburetor at the factory, the throttle adjusting member is brought into a certain position by means of a position feedback value of the throttle adjusting member, locked and the throttle valve is

  associated mechanically with a predetermined air flow rate

  mined, usually by means of a set screw.

  Thus, the position of the throttle adjustment member

  and its position feedback is a reference

  precise accuracy for the throttle position.

  To the extent that a proper adjustment of the potential

  repetition meter of the position of the regulator

  butterfly is not performed, the value of the feedback signal is posi-

  This invention presents dispersions of a carburetor

the other.

  Therefore, it is already known from German Offenlegungsschrift No. 3,312,027 to adjust, in a given zero point situation, the output signal of a transmitter system to an adjustable value. This should remove an adjustment

individual.

  US Pat. No. 4,637,361 discloses a

  assigned for the determination of the position of the butterfly in the-

  which a mechanical adjustment of the position repetition potentiometer can be suppressed because the least opening position occurring during the permanent monitoring

  is reported and used for the determination of the pa-

closed pillon.

  It is thus possible to compensate for wear influences

  possible of the control mechanism and the potentiometer.

  It appears from the two proposals that an adjustment

  can be practically carried out only at a defined zero point

  which may not be achieved in the conditions of service

  vice or is reached only after a period of service

long enough.

  The object of the present invention is therefore to indicate a method of the above kind which makes it possible to rapidly correct

  individual dispersions without mechanical adjustment.

  The invention then starts from the following reflection:

  When the throttle is moved by the adjustment member of

  pillon, one obtains for each carburettor

  characteristics of the value of the position potentiometer of

  pillon according to the value of the repeat potentiometer

  position in the region of the papilla set point.

  lon, with the throttle adjusting member in a fixed position, have a minimum distance relative to each other.

  to others but which may have a variable slope (Fig. 2).

  A uniform reference can be obtained by moving all characteristic curves to the intersection point.

  the most-elevated characteristic curves that are

  in the region of the set point so that all characteristic curves pass through the same point

(Fig 3).

  The envelope of the family of characteristics de-

  ends up with a characteristic lower than the minimum values of the displaced characteristic curves and with a higher characteristic, the maximum values of the displaced characteristic curves (Fig. 4) within which

  the butterfly can be moved by the adjusting member of

  pillon. Above the upper characteristic of the maximum values, the throttle is always set by the accelerator pedal. On the basis of this, this goal is achieved by the fact that

  for subsequent operation, an association of the

  their position feedback signal (a) at each position of the adjustment element and respectively at each value of the position feedback signal (S) only occurs after calibration on a value (a ') determined by a characteristic (Ku ), by adding a calibration value (aT) so that (a ') is increased at least up to the value of the characteristic

  Advantageous features of the process make the ob-

jet of sub-claims.

  The description that follows, next to the drawings

  annexed by way of non-limiting examples, will

  understand how the invention can be put into practice.

  Figure 1 shows a block diagram and block diagram;

  Figures 2 to 5 show diagrams.

  Fig. 1 represents a block diagram and schematic

  block of a device for adjusting the idling speed of an internal combustion machine 1, with a device

  throttle (control element) 2 which controls the air and.

  respectively the fuel mixture of a system of forma-

  not shown mixture (carburettor or injection), with a butterfly 4 arranged in a suction pipe 3 and a throttle lever 6 mounted on a throttle pin 5, the

  which throttling lever is pushed under the action of a res-

  closing fate 7 against a butterfly adjusting member (adjusting member) 8 when the throttling device 2

  is not opened by the engine operator.

  The throttle adjusting member 8 has a potential

  position repetition tiometer 9 and the foreign device

  2 is equipped with a positivity repetition potentiometer

  10. The values of the potentiometric signals are trans-

  set to an electronic control device that includes a

  device 12 for interpreting the values of the signals.

  The control apparatus 11 comprises, inter alia, a

  memory for the set rotation speeds of a pro-

  engine control gram which are compared with

  the actual values of the speed of rotation, the difference

  sent as a correction value to a re-entry

  idle filling gib 13 o it is transformed into a signal which corresponds to a theoretical value determined

  (atéor) of the opening of the butterfly and is transmitted to a

  position controller 14. The embodiment of the filling regulator and the position regulator respectively

  may be arbitrary, that is, it is possible to

see regulators P.I.D.

  Fig. 2 shows a diagram with characteristic curves

  the value of the throttle position signal (a) indicated according to the value of the position feedback signal

  of the throttle adjustment element (S) for a number of car-

  identical bureaus, in accordance with the form mentioned above, and highlighting the individual dispersion of

signal value (a).

  Fig. 3 shows a diagram in which the characteristic curves of FIG. 2 are shifted to the point of intersection of the highest characteristics in the range of a predetermined value of the position retrosignal (SE), i.e., all characteristics pass through a point B. FIG. . 4 shows a diagram with envelopantes of the family of characteristics in bundle according to FIGS. 2 and 3. FIG. 5 shows a diagram according to FIG. 4, the envelopes being represented at point B with a slight shift relative to each other for reasons of tolerance. The enveloping thus form a lower characteristic (Ku) and a higher characteristic (Ko), and

  they indicate calibrated values of the signal (a ').

  The process according to the invention is described with regard to

fig. 1 and FIG. 5.

  The adjusting member and the butterfly adjusting member 8 shown in FIG. 1 has been adjusted by

  setting at the factory to a position determined by a

  their position retrosignal (SE) defined; at this position

  the control element and respectively the

  throttling device 2 according to a predetermined air flow rate.

mined, that is to say set.

  The values of the signals (S) and respectively (a) of the position repetition potentiometer 9 and respectively of the position repetition potentiometer 10 are transmitted to the

  interpretation device 12 of the control apparatus 11.

  The interpretation device 12 comprises at least one table memory or identification zone in which

  is recorded at least the characteristic (Ku) which has been de-

  developed according to the diagrams in fig. 2 to 5, from

  individual dispersions (a) of the different carburettors.

  When operating the internal combustion machine

  dull, an association of the signal value (a) with each

  their position feedback signal (S) only occurs after the

  setting on a value (a ') predetermined by the characteristic

  (KL) since the value of the signal (a) is less than

  than the value of the characteristic (a '), that is to say

  that (a ') is aligned at least with the value of the characteristic

tick (Ka>.

  The calibration is done by adding a calibration value

  (aT), said addition being effected only in the positive direction

  tif. The diagram in fig. 5 shows a characteristic Ki of the signal value (a) for the object of FIG. 1 which may correspond to any characteristic of the

diagram of fig. 2.

  As the signal values (S) and (a) get closer, from the higher values area,

  characteristics point B, as is the case for the ob-

  jet of fig. 1 since, for a cold engine, a larger idle air flow rate is set, no calibration occurs up to the point of intersection of the characteristic (Ki) with the characteristic (Ku) since the value of the signal

  (a) is larger than the characteristic value (a ').

  As the motor heats up, the air flow is reduced so that the signal values (S) and

(a) also decrease.

  According to the characteristic (Ki), the value of the signal (a) falls below the characteristic value (a ') of

so that a taring is done.

  At the value of the signal (a) is then gradually added a calibration value (aT) until the calibration value (aT)

  becomes maximum in the range of the signal value (SE).

  This taring value (aT) once reached is kept during operation, even if there is an increase

  signal values (S) and (a), which gives a characteristic

ristique (KT) in fig. 5.

  The process according to the invention thus entails the formation of

  signal values (a ') whose characteristics

  always feel by the point B of the characteristic (Ku), and this independently of the individual dispersions. For the

  operation of the internal combustion machine, that association

  A much more precise indication of the signal values (S) and (a) and the position of the setting and control elements respectively gives advantages with regard to a

  more precise respect of the idling speed

  determined, which makes it possible, among other things, to save money

  fuellines. Moreover, the method according to the invention has also, unexpectedly, made it possible to obtain exact information on the question of whether the control device

  is actuated by the adjusting element or by other means

  fluences, as for example here by an operator of the engine.

  As can be seen from the diagram in FIG. 5, a

  tion by the adjusting element can be excluded in the

  area above the Ko feature.

  Likewise, actuation by other influences can be

  excluded in the area below the characteristics (Ku).

  However, for the area between the two characteristics (RKo) and (Ku), it is impossible to give unequivocal information on the state, actuated by the adjustment element. For a

  interpretation, it can be assumed that this is an action-

ment by the adjustment element.

  However, where that decision is not acceptable

  table, the procedure provides that in the area between the

  (Ko) and (Ku), a response to the question of whether or not there is actuation of the setting element can be found by a comparison of the signal values (S) and ( (a) which vary with respect to the direction and

  of the variations, and by an interpretation of the

reason.

  Since the characteristic (KT) is recorded and

  searchable, it is also possible to exclude an action-

  above the characteristic (KT).

  This has the advantage of idle detection that

  can be done without the usual idle switch-

used so far.

  It goes without saying that the method according to the invention is also feasible if, in place of the value of the signal (<), the calibration is done on the value of the signal (S) and that

  this does not go beyond the scope of patent protection.

Claims (9)

  1. - Method for setting a value of retro-   position signal (a) of a control element adjustable by   an adjusting element in combination with an ignition device   interpretation, for which a) the adjustment element is brought to a position defined by a position feedback value (SE) of the predetermined adjustment element; b) to the adjustment element brought into this position; element   control is mechanically associated with a range of   predetermined value of a control variable; c) the value of the position feedback signal (a) of the control element is detected; and d) transmitted, together with the value (S) of the control element signal, to interpretation device, characterizes that, for the functioning   consecutive, an association of the value of the retro-signal of   (a) at each position of the adjustment element and   respectively at each value of the position feedback signal (S) intervenes only after setting a value (a ') determined   by a characteristic (Ru), by adding a value of ta-   rage (aT) so that (a ') is increased at least until the value of the characteristic (Ru).   2. - Method according to claim 1, characterized in   that the calibration is carried out only in the positive direction.   3. - Method according to one of claims 1 or 2,   characterized in that the maximum tare value (aT)   hue in operation is retained.   4. - Method according to one of claims 1, 2 or   3, characterized in that the characteristic (Ru) has, from, the value of the position retrosignal (SE) determined   in step a), a lower slope in the direction of their biggest.   5. - Method according to one of claims 3 or 4,   characterized in that the tare value (aT) is maximum   in the range of the signal value (SE).   6. - Method according to claim 5, characterized in that the characteristic (KT) obtained after reaching the maximum setting value (aT) defines the range of adjustment of the control element that can be performed by the element adjustment. 7. - Process according to claim 5, characterized in   what a predetermined superior characteristic (Ko) delimits   mite the range in which, following individual dispersions, the characteristics (KT) after   reaching the maximum taring value (aT) and in the-   which adjustment can be made by the adjustment element.   8. - Method according to one of claims 6 or 7,   characterized in that for values (a ') of the sum of the   value of the position feedback (a) and the value of ta-   rage (aT) exceeding the characteristic KT and respectively indicated Ko, a setting of the control element by the element of   setting can be considered as excluded.   9. - Method according to claim 7, characterized in that in the area between the upper characteristic (Ko)   and the lower characteristic (Ku), a response to the question   whether or not there is a setting of   the control element by the adjusting element can be obtained   by comparing the signal values (S) and (a) which   the direction and relationship of variations, and by an interpretation.