FR2700808A1 - Method and device for controlling a drive group of a vehicle - Google Patents

Abstract

a) Control method using a stepping motor control system. b) The stepping motor is controlled on the basis of a setpoint, - the position of the installation, evaluated by the detection of the pulses is compared with the aid of a one-position step counting means normalized predetermined and, - in the event of a difference from the normalized position, the control signal at the basis of the control of the stepping motor is modified.

Description

"Method and device for controlling a group of

trainings of a vehicle ".

  The present invention relates to a method and a device for controlling a drive unit of a vehicle, and in particular to a control method using an adjustment device for influencing

  the power of the training group, this facility

  tion being actuated by a stepping motor.

  The invention also relates to a device

  with a setting system to influence the power of the motor, a stepper motor for

  In the control system, a control unit for setting the stepper motor in the direction of a setpoint value. Such a method and such an apparatus is known by way of example for idle control. of thermal combustion engines according to German Offenlegungsschrift No. 2,523,283 (US-A-3,964,457). This document proposes a regulation of the idling speed by a speed control circuit which, on the basis of the The deviation between the measured value of the rotational speed of the motor and a predetermined target rotational speed governs a positioning member influencing the speed of rotation of the motor, in particular a throttling flap controlling the air supply to the engine. using a stepping motor, in the direction bringing the actual value of the setpoint value of the speed of rotation The method described in this known document, does not envisage variations in the environment of the regulation, as for example aging phenomena or effects due to air leakage or influences on the regulator caused by incidents or losses

to not.

  According to the state of the art, the first drawbacks can be corrected or avoided by the known adaptation methods. For example, DE-OS 34 29 351 (US Pat. No. 4,815,843) describes such an adaptation that is necessary for a speed control of idling Then we enter the output signal of a

  regulator preferably having a proportional part

  An integral and / or differential part on the basis of this signal, the long-term deviations of the output signal of the controller from a value corresponding preferably to the middle of the control range of the controller are determined and recorded. Stationary operating mode The stored value is added to the control signal in the sense of a pre-command so that the control output signal and thus the controller

  itself is in the ideal case, in operating mode.

  stationary, always in the middle of his

  control geometry The ideal value of the controller output signal can be set by adjusting the idling speed, eg using the idle screw. The standard position of the control system thus connected is known for each type of engine. adaptation thus described compensates for drift, aging and / or air leakage irregularities caused by incidents and step losses that are reflected by an erroneous value of the counter of

  not representing the position of the

  are not corrected in this way.

  The present invention thus aims to develop a method and a control device

  of a vehicle training group for the purpose of

  to ensure that irregularities caused by

  loss of steps or other incidents may be cor-

  by the control installation equipped with a

step-by-step engine.

  For this purpose, the invention relates to a method characterized in that when the position of

  the control facility evaluated from the

  If information transmitted in the step counter differs from a predetermined normalized position for a predetermined operating state, the control signal at the base of the motor control is modified.

  step by step so that the state of the step counter is

  close to the normalized, predetermined position.

  In other words, the process is characterized

  in that the stepper motor is actuated according to a

  control signal on the basis of a value of

  sign in the direction of a setting of the setpoint value, the position of the setting system, evaluated by the detection of the transmitted pulses is compared preferably using a step counting means at a normalized position predetermined in at least one predetermined operating state and, if there is a difference from the normalized position, the control signal at the base of the stepper motor control is changed so that the value of the evaluated position approximates the

  predetermined normalized position.

  The method according to the invention makes it possible to take into account and correct the irregularities of regulation,

  caused in particular by loss of steps.

  This makes it possible to use the advantages of a stepping motor to control an adjusting member influencing the air supply of the internal combustion engine,

  and which allows simple control of control loops

  open without position feedback.

  It is particularly advantageous that the

  method according to the invention simulates the position of the in-

  setting stallation and exploits it for correction

irregularities.

  It is advantageous, when clearing irregularities, to take measures to avoid

  moving the adjustment system.

  The advantageous correction of the necessary adaptation is obtained in that step losses or other incidents such as for example a stop taken from

  wrong way as a point of reference for the

  step to simulate the position of the control system are corrected without the correction factors relating to drift and

  aging process will be distorted.

very simple procedure.

  Other advantages will appear on reading

  of the description of embodiments given below.

  FIG. 1 shows a block diagram of an assembly of a control unit of a drive unit using a stepping motor.

  to influence the power of the motor.

  Figure 2 shows a characteristic curve

  tick of the adjustment system (from the motor

  step and shutter connected to this engine).

  FIG. 3 sketches a flowchart for implementing the method of the invention in the form

a calculation program.

  Description of the exemplary embodiment

  FIG. 1 shows an overall diagram, in blocks corresponding to a preferred embodiment of a control unit for the implementation of the

  Method of the Invention The control unit 10 comprises

  lines of entry 12 14 connecting the communication unit

  command 10 to measuring facilities 16 18 to detect the operating parameters of the group

  drive and / or the vehicle (described later-

  In addition, the control unit 10 has

  least one line of exit 20 which connects the unit of com-

  to an electric motor (stepper motor M), 24 equipping an internal combustion engine 22 itself

  shown schematically The combustion engine

  internal circuit 22 comprises inter alia a measuring installation 26 for detecting the speed of rotation N of the motor, connected by line 28 to the control unit

1 O.

  The control unit 10 itself comprises a unit 30 forming a set value to which the lines 12 and 14 are connected, and in a preferred embodiment, also the line 28. The output line 32 of the unit 30 connects this line. unit to a difference circuit 34 which further receives the

  line 28 The output line 36 of the difference circuit

  34 is connected to the control unit 38

  The exit line 40 of the regulatory unit

  38 leads to a combination point 42 whose output line 44 leads to a step generating element 46 The output line 48 of the generating element

  of step or more simply of the generator of step 44

  by means of a switching element 50, shown schematically at the output line 20 of the control unit 10 The switching element 50 is actuated by a locking element 52 via a line 54 For

  reasons for simplifying the drawing, the element of ver-

  rust 52 is connected to lines that provide him with

  information necessary for taking decisions

  for locking the control.

  The locking of the control by the switching element 50 is only represented so

  symbolic in Figure 1 In the example of

  In a preferred embodiment, the locking consists in not generating an output signal for controlling the motor

adjustment.

  In addition, the control unit 10 comprises an adaptation unit 56 which receives the input line 58 of the connection line 40, the input line 60 of a release unit 62 and the line of input 64 of a comparison unit 66 The output line 68 of the adaptation unit 58 is connected to the combining element 42 As was the case above for the locking unit 52, for the liberation unit 62 has been renounced to represent the lines of entry

  to provide in return the operating parameters

  from lines 14 to 16 for the purpose of simplifying

  The comparison unit 66 is connected by a connecting line 70 to the step generator 46; another input line 74 from another element

  72, which according to another example of reali-

  In a preferred embodiment, it may be identical to the release element 62; the lines providing the expected operating parameters have not been shown either. The operation of the assembly shown in FIG. 1 will be described hereinafter by way of example for an idle speed control.

  stepper motor 24 of the preferred embodiment

  is connected to a control valve mounted

  in a derivation of the main throttle

  pal of the air intake system of the combustion engine

  According to other advantageous examples of application, the stepper motor can be used to adjust a thrust thrust stop, the main throttle

  for idle speed regulation as well as for

  throttle throttle throttle throughout its operating range as part of an electronic throttle pedal; the stepper motor is then controlled according to the driver's command value. Other applications may also be considered in connection with the shutter of an air-conditioning system, with a system for regulating the slip at the drive, for the blind

  auxiliary or the main stranding

  pal. The setpoint generator 30 forms

  a rotation speed reference value of

  lenti Ncons according to the parameters of the group of

  trailing and / or vehicle transmitted by the input lines 12 14 from the measurement facilities 16 18; this set value is provided by the line 32 to the element forming the difference 34. As operating parameters according to a preferred embodiment, the engine temperature, the battery voltage, the selected gear ratio, the operating mode are used. of transmission, the speed of the vehicle, the state of accessory users such as that of an air-conditioning installation,

  the signal of an idle switch, etc. or

  according to a preferred embodiment, the

  speed of rotation of the motor (see line 28

  interrupted) The difference generator

  34, links the set value formed to the actual value of the speed of rotation of the motor N to form the control deflection Delta N This

  Delta N is supplied to the control system

  In the context of a regulatory program which, according to a preferred embodiment,

  has a proportional part, an integral part

  grale and / or differential, forms a QR regulator output signal transmitted by line 40 and the point

  42 and 44, at the general

  The latter associates the output signal with

  This number is then supplied by the output line 20 to the stepper motor 24 as control signals St, shifted by 900 to adjust the number of steps to be executed. engine air supply 22 into

  taking into account the control installation.

  The stepping motor 24 is thus set

  the importance of the difference so that the actual value of the rotational speed of the motor reaches the

  setpoint rotation speed, predetermined.

  The described control system is designed so that at a predetermined operating point, when the engine is warm and for idle operation without accessory users being connected, the regulator output signal is in the middle of its range. ; this means that the control unit 38 is in the middle of its control range. In this way, the behavior of the control system 38 is advantageously linear in both directions for excursions.

  from this ideal state of operation

  fluences such as phenomena of drift and / or aging or even multiple air leaks,

  can only be done in the sta-

  described above, the output signal of the controller deviates from the ideal central value for

  predetermined value of the regulating output signal

  The control output signal may be in the limit zone of the

  regulation, so that the regulatory characteristics

  lation may be unsatisfactory in

less a direction of variation.

  This is avoided by the so-called adaptation of the

  request, which is performed by the accommodation unit 56.

  When the release unit 62 finds the stable idle operation mode of the engine for normal conditions, for example using the signal of the idle switch, using a time condition, the a speed signal, using the speed signal, the temperature signal and / or the accessory user status signal, this unit provides the adaptation unit 56 with a signal The adapter unit integrates the difference between the instantaneous output signal of the regulator and the

  predetermined value of the output signal of the regula-

  tor; this difference is recorded The value

  registered QADP is applied by line 68 to the signal

  output of the regulator at the point of combination 42.

  This means that by adding a correction value

  QADP output to the controller output signal, this signal remains essentially at its predetermined value in the middle of the control range, in idle mode operation, stationary, regardless of the operating parameters of the motor. to the step generator 46 by the line 44 to adjust the stepping motor, remains

  thus identical; only the values of the output signal

  the regulator and the QADP correction value

will be moved.

  The steps emitted by the step generator are counted and, for example, when the stepping motor is actuated in the direction of travel, a count is made while for reverse gearing, a countdown is performed. SZ counting of the step counter represents a measurement of the position of the stepper motor and thus simulates the position of the control system which does not have any other information in 1 O return Next to the modifications mentioned above

  caused by drift phenomena, aging

  and / or variations in air leakage, when using a stepper motor, irregularities may be encountered resulting from the loss of steps as a result of a mechanism operating with difficulty when the engine is cold or because of short-term shocks in normal operation, due to spurious pulses or due to a false zero position (position of the control system against the lower stop, state of the step counter equal to zero which is taught in phase start-up according to an example of

preferential realization).

  Because of these irregularities, the actual rotational speed corresponds to the set rotational speed and the step counter SZ used to monitor the position of the stepper motor has a distorted value with respect to the actual position.

  stepping motor This is particularly important

  so much if the stepper motor command is done no

  not as shown in Figure 1, only

  depending on the rotational speed deviation

  tion, but on the basis of the deviation of the setpoint position generated by the stepper motor control unit 38 and the actual position defined by the step counter SZ, again for the stepper motor. To correct these irregularities, the procedure is as follows: In stationary operating mode at idle, detected by the release unit 72 as well as by the locking unit 52 using the signals described above, the comparison stage 66 is activated This stage compares the step count state SZ supplied by line 70 for a speed of 1 O idle rotation set by the normalized position KENPOS, for stationary operating mode at idle. This normalized position corresponds to the position of the adjustment system for speed

  idle speed, set, prescribed and apply

  that to each type of engine being thereby

  naked. Figure 2 shows the characteristic curve

  stepping motor or setting system.

  The horizontal axis represents the airflow demand Qair between its minimum value and its maximum value; the perpendicular axis represents the POS position of the control unit between the minimum value and the maximum value. The air flow demand for stationary idle QLL thus represents the air flow required in the control installation to maintain the speed of rotation set (for example

  using a set screw) Depending on the characteristic curve

  FIG. 2, at this idle value, corresponds to an operating position at idle KENPOS of the adjustment installation; this position

  guarantees the necessary air flow This normal position

  male KENPOS is represented by a state of the step counter, because there is no feedback for the

  actual position of the adjustment system.

  The phenomena of drift and aging

  in the regulation of the speed of rota-

  of the idle speed, which is reflected by a deviation between the actual value and the setpoint value of the speed of rotation, such as an increase in the leakage air fraction, is compensated by

  the regulator, by issuing the number of steps required

  to adjust the actual value to the set value The controller thus leaves its average value

  1 O provided for the ideal case when the rotational speed

  The idle speed is adjusted (eg by an idle screw). The corresponding deviation of the

  regulator output relative to a predefined value

  completed (ideal value) is detected by the adaptation unit which compensates for this deviation by calculation of the correction value QADP for the regulator

  take again its ideal value.

  If you lose your step, you have the same

  One or more steps to the engine

  are not executed, this results in a deviation

  regulation between the set point and the

  actual value of the rotation speed; this deviation

  This is reduced by the emission of other steps. The output signal of the regulator leaves its ideal value.

  is compensated by adjusting the value of the

  QADP and the step counter changes.

  In other words, adaptation to the

  in the QADP coefficient contains all error states, all deviations and changes in

  the domain of the regulation circuit, that is to say all

  The QASP coefficient thus constitutes a measure of the importance of these variations. The method according to the invention is based on

such considerations.

  The losses of steps and only these are corrected by the method according to the invention, whereas the components of the coefficient QADP resting on

  other deviations and changes are not

  by the method described above.

  When the comparison installation 66 finds in the case of idling, for a determined rotational speed, a deviation between the step count state SZ and the normalized position KENPOS,

  the locking unit 52, it locks the control

  stepper motor; according to Figure 1, this means the opening of the switch 50 shown

  schematically and adaptation to demand is

  Then, the adaptation value QADP is incremented or decremented by the comparison facility 66 and the line 64 according to the sign of the deviation. This continues until the count state of not SZ corresponds to the

  standardized value KENPOS Then we remove the ver-

  rusting of the stepper motor control and

  adaptation to demand and we take over the functioning

  Idle speed regulation By modifying the correction coefficient, to regulate the idling speed after the regulation has been restarted, it may be necessary for the regulator to intervene deviations from its value.

  are then compensated again by adapting

  on demand The QADP correction coefficient no longer contains the components caused by the

step losses.

  According to an advantageous exemplary embodiment, when stationary idling operation is observed, the comparison unit 66 is activated at a predetermined time after the last activation A c 6 té of the incrementation or decrementation, one can

  in other examples of

  advantage, an addition or subtraction of a coefficient greater or less than 1 In addition,

  can advantageously have a correction of the coeffi-

  QADP correction in the context of a predetermined function of time, for example on a linear, exponential, parabolic, etc. The measurement of the variation of the QADP value can also be

  choose according to the time, according to the

  rotation, etc. The process described above to correct

  the loss of steps in the form of a cal-

  ass is sketched by the flow chart shown in

figure 3.

  The program part described in FIG. 3 takes place next to the idle mode regulation, itself, not shown in FIG.

  3 The program part according to Figure 3 is

  started at predetermined times, initialized following

  the duration of operation, the mileage

  and / or from outside by a service device

  In the first step of program 100, we introduce

  duit the necessary parameters for the next program.

  These include, in particular, the motor rotation speed, its temperature, an idle switch signal, etc. as well as the step count state SZ, the regulation value QR and the value of QADP correction In the interrogation step 102,

  next, we check whether there is a functioning state

  suitable for performing a loss correction

  of step, a state of idle, stationary, stable.

  This interrogation is done according to the signal of rotation speed of the engine which must not change in a certain time, the temperature of the engine, the

  voltage signal of the battery, the operating signal

  when such operating state is not detected, the program part stops. In the opposite case, for a state of

  stationary operation, in step 104, one ver-

  rust control of the stepper motor and the execution of the adaptation on demand and the standardized value KENPOS is introduced Then, in step 106, it is checked whether the step count state SZ corresponds to the value of the standardized position KENPOS, and in an advantageous embodiment, this is done taking into account a delta tolerance coefficient. If this is the case, it is concluded that there has been no loss of step and according to step 108, the control of the motor is terminated and the adaptation on request and the program part are released. In the opposite case, in step 110, it is checked whether the state of the step counter is lower than the standard position, if necessary taking into account the delta tolerance range Si

  this is the case, we increment the coefficient of cor-

  QADP in step 112, whereas in the contrary case

  re, the correction coefficient QADP is decremented in the step 114 Then, in the step 116, the step counting state SZ is adapted as a function of the output signal of the regulator QR and the correction value QADP is the variation forming the steps issued because of the variation of the QADP coefficient; however, because of the lock, these steps do not apply; we adapt

  and we finish the program part.

  By cyclically traversing the program part shown in FIG. 3, it is obtained that after a certain number of correction steps, the state of the step counter is adapted to the normalized position and thus compensates for a possible loss of

  After this procedure, we release new

  the motor control and the speed control is again carried out. This allows

  to correct the loss of step without adjusting movement.

  In addition to the application described above in the context of idling speed regulation of a spark-ignition gasoline engine, the method of the invention can also be applied to pedal systems. electronic throttle as well as diesel engines, for adjusting the

control rod.

  A comparable method can be applied if the reference point of the step counter corresponding to the stop of the stepping motor against one of the stops

  end of travel of the actuator is defective.

  By setting the state of the step counter to the normalized position, in the

  idle, stationary, we obtain a reference point

  which compensates for the final value that was poorly learned.

  The method thus corresponds to what has been described above (FIG.

  Learned is reflected by the counting state of the erro-

  born and gives an effect comparable to that of a loss of step As a result, one can proceed in the same way

for compensation.

Claims (9)

R E V E N D I C A T IO N S   1) Control method of a training group   of a vehicle with the aid of a regulating member for influencing the power of the driving unit, this member being actuated by a stepping motor, characterized in that: the stepping motor is actuated by function of a   control signal on the basis of a value of   sign in the direction of an adjustment to the setpoint, the position of the adjustment member, evaluated by the   detection of transmitted pulses is compared   using a step counting means at a predetermined normalized position in at least one predetermined operating state and   if there is a difference from the normal position   the control signal at the base of the com-   the stepper motor is changed so that the   value of the evaluated position approaches the   predetermined standard set.   2) The process according to claim 1, wherein   controlled by a regulation of the speed of rotation of the motor and in the context of an adaptation, one controls   the output signal of a regulator for deviations   to a predetermined value and a correction coefficient (QADP) related to the output signal of the regulator is recorded to control the step-by-step engine.   3) Method according to one of the claims   precedents, characterized in that in case of non-coinciding   between the state of the step counter and the posi-   the correction value is corrected   where appropriate taking into account a range of rancid.   4) Method according to one of the claims   preceding conditions, characterized in that the correction of the correction value is carried out until the state   the step counter corresponds to the normal position   if appropriate taking into account a tolerance range.   Method according to one of the claims   previous, characterized in that the control of the stepping motor is locked during the correction the correction value.   6) Method according to one of the claims   preceding, characterized in that the correction of the   correction value is done in the operating state. idle, stationary.   7) Method according to one of the claims   preceding, characterized in that for a state of   counting too small, the value of the cor-   rection and for a counting state that is too large   decrement the correction value.   8) Method according to one of the claims   preceding, characterized in that the normal position   the position which is that of the hand-   your idle air demand for tuning idle ideal.   9) Control device of a group of   driving a vehicle with an adjusting member to influence the power of the motor, a step motor for operating the adjusting member, a control unit for adjusting the stepping motor in the direction of a set point , means being provided for actuating the stepper motor as a function of a control signal on the   basis of a set value in the direction of a re-   setting to the nominal value, means preferably a step counting means which, by entering the transmitted pulses, evaluates a position of the adjusting member, comparing to a predetermined normalized position   in at least one predetermined operating state   nd, and in case of difference from the normalized position, the control signal at the base of the stepper motor control is modified so that   the value of the evaluated position adapts to the posi- predetermined standard   10) Device according to claim 9, characterized in that the control of the stepper motor is locked for control and correction of a possible loss of step is done without actuating the stepper motor.