FR2809059A1 - METHOD AND DEVICE FOR CONTROLLING A POWER UNIT OF A MOTOR VEHICLE - Google Patents

Abstract

Method and device for controlling a motor unit of a vehicle according to which, during the operating state with the clutch slipping, the target rotation speed and / or the torque reserve to be adjusted is increased.

Description

STATE OF THE ART The present invention relates to a control method

  of the motor unit of a vehicle, according to which a signal of generation is generated

  command as a function of a setpoint variable, signal which controls at least one actuator influencing an output variable of the motor unit, the setpoint variable being influenced as a function of the state of the clutch. The invention further relates to a drive unit control device of a vehicle comprising a control unit which, as a function of a setpoint quantity, generates a control signal for an actuator influencing an output quantity of the drive unit, and which determines the operating state of a clutch of the drive unit and

  modifies the set value according to the state of the clutch.

  According to document DE 34 26 697 C3, a process is known.

  duration consisting in regulating the speed of rotation (speed) of the drive unit to a predefined set value. To take into account in the idle range the different loads applied to the drive unit during the operating state of true idle (cut-off force transmission) and

  the operating state with a closed force transmission, it is pre-

  seen to raise the setpoint speed of the speed controller when the force transmission is established in the line of

  transmission between motor and output. Thus, the regime is raised during-

  that a gear has passed and that the clutch is closed. Certainly this pro-

  procedure applied with the force transmission line established and in true idle mode with the force transmission line cut off,

  allows a better regulation of the regime, but the transient state, no-

  the clutch slip state is not taken sufficiently into account.

  account. This is why the known regulation is not optimal.

  According to document DE 195 17 673 (US-5,765,527), it is known in certain operating states, preferably at idle, to

  provide a predetermined reserve of torque thanks to the ignition angle.

  In this case, the output which, apart from at least one operating state,

  is kept within an optimal range, is deteriorated by correspondingly modifying the air supply and the ignition angle. For the same drive unit torque, by increasing the air supply and delaying the ignition angle, there can be sudden and rapid variations in the torque by modifying the ignition angle, also in the direction

increase in torque.

  Advantages of the invention To this end, the invention relates to a process of the defined type

  above, characterized in that for the duration of the operating state

  m. - -: - ment-correspondent -a "u - 'skate-age - de-l'-clutch-ela-'grandeur-de consigne has a value increased compared to its value in at least one other

operating state.

  In addition, according to the invention: - the reference variable is a reference value, preferably a reference rotation speed, a reference torque, a power

  set point i0, a set point filling or a set air mass

  gene and / or a torque reserve to be adjusted according to the ignition angle, - the clutch slip state is determined from the clutch stroke, or if the clutch stroke leave her

"total opening" value.

  The procedure described optimizes the transition between a state with a cut power transmission line and a state with a

  closed force transmission line. In particular, by the limited elevation

  time setting of the active regulation setpoint, in particular

  the idle setpoint speed or by increasing

  limited in time from the torque reserve when passing from the position

  locked in the clutch slipping position and during slipping, the problem of decreases in rotation speed at start-up or during slow movement of the vehicle is effectively avoided, in particular when the accelerator pedal is released. These excursions below speed

  that occur at startup or slow motion no-

  Especially in vehicles with automatic gearboxes, which result in a deterioration of comfort or engine stalling, occur especially in vehicles whose idle speed has been lowered. This is why it is particularly advantageous to apply the

  proceeded to gasoline engines including direct injection.

  In addition, when starting or moving the vehicle slowly

  With a clutch slipping, the disruptive magnitude of the clutch torque generates unpleasant body vibrations. However, the means set out above ensure a significant improvement in traveling comfort, in particular the reduction of these oscillations of

  bodywork and improved acoustics when the clutch is

  tine. It is particularly advantageous that the transition from the clutched open state to that of slipping is detected exactly by detection

  of the clutch stroke. This is why the clutch stroke is deter-

  mine by measuring the clutch pedal stroke or by measuring

  sure of the travel of another moving part of the clutch.

  Advantageously, a disadvantage is avoided.

  summation at idle speed thanks to the measures mentioned, limiting in time these measures to the operating range of the clutch in the slip state. Comfort is improved even more if the transition from skating to fully engaged state reduces the increase in value

  setpoint or increasing the torque reserve to the previous value

  during its lifting by temporarily filtering it. So after leaving

  the clutch slip state, the setpoint value is increased

  to decrease it according to a predetermined time function, no-

  a filter function from the increased value.

  According to other advantageous characteristics: - the control quantity is determined by an idle speed regulator, which determines the control quantity as a function of the target rotation speed and the actual rotation speed, - it is adjusted the torque reserve by increasing the filling of the engine

  internal combustion and delaying its ignition angle.

  For the implementation of the method, a device of the type designated above is provided, in which the control unit determines

  the slip state of the clutch and, for the duration of this state of operation

  operation, increases the target quantity compared to its value

  in another operating state.

  Improvement of ride comfort and elimination or reduction of under-speed oscillations during starting and / or slow movement of the vehicle by raising the setpoint and / or increasing the torque reserve are sufficient measures, since the idle stroke of the clutch until the application of the clutch torque to the drive unit provides a preliminary movement, sufficient in time after actuation of the clutch. For this reason, it

  nor is it necessary to maintain the clutch clutch torque

  marrage outside the start operation. This also reduces the torque reserve when the clutch is open. The procedure described thus leads to better behavior in the operating state.

  with clutch slip without consumption disadvantage or

  very. Drawings The present invention will be described below in more detail

  detailed using the embodiments shown in the drawings an-

  attached in which: - Figure 1 shows a diagram of an idle speed regulator, - Figure 2 shows the method according to the invention using a preferred embodiment presented in the form of a flowchart, - Figure 3 shows by chronograms, the operation of the mode

presented.

  Description of the exemplary embodiments

  Figure 1 shows a diagram of a cruise control

  usual rotation in the form of a flowchart executed in a half

  mainframe 10 of a control unit of the motor unit of a vehicle

  cule. A setpoint generator 12 forms the speed of rotation

  Nsoll idle setpoint; it receives through input lines 14-18 the si-

  signals supplied by 20-24 measurement facilities representing the

  operating rameters or from which the operating parameters of the power unit and / or of the vehicle are deduced. Depending on at least one of the operating parameters thus applied, the

  idle setpoint speed, from a characteristic curve

  of a table, a field of characteristics or by proceeding

  by calculation steps. Characteristic operating parameters

  What are the engine temperature, the position of the gearbox, the

  battery voltage, etc. In addition, a corresponding measuring installation

  dante provides a signal representing the clutch stroke.

  The measuring installation is constituted, depending on the embodiment, by a stroke sensor for actuating the clutch pedal or a stroke sensor which determines the stroke of a movable element of the clutch and from this ci it is estimated that the clutch is open, in slip or is engaged.

  Depending on at least one of these quantities, the general-

  setpoint value 12 provides the setpoint speed

  Nsoll and transmits it to a comparator 26. This also receives the vi-

  Nist actual rotation tesse provided by a rotational speed sensor and transmitted by the line 28. At the combination point 26, preferably by forming a difference, the deviation between the actual Nist rotational speed and the rotational speed is constituted. Nsoll setpoint. The regulation deviation A is applied to the regulator 32_ which generates an output signal X according to a predetermined regulation strategy; this output signal is applied by the output line 34 to an electrically actuated actuating element 36. This actuating element (actuator) influences the speed of rotation of the drive unit. According to the example of realization,

  different strategies are implemented in regulator 32. An example

  full of such a strategy is a regulator with a proportional component

  tional, integral and / or differential. In the preferred embodiment, the actuator 36 influences the air supply or the load of the internal combustion engine. In other exemplary embodiments, as a variant or in addition, the ignition is adjusted and / or the fuel is metered using regulator 32. In diesel engines, the regulator acts on the quantity of fuel; in direct gasoline injection engines in stratified mode, it also affects the quantity of fuel; in the

  in the case of electric motors, it acts on the control current.

  In another exemplary embodiment, to improve the

  operation of the idle speed control, a further

  improvement of idling performance; for this we increase the diet

  in air and the ignition angle is delayed to maintain constant torque.

  Thus, thanks to the ignition angle, a reserve of torque is achieved which allows

  both by advancing the ignition angle to ensure a very rapid variation

  of the couple even in the direction of its increase.

  The above description relates to a simple regulation

  idle speed. The procedure described below is not applied in such speed regulators but in regulators which regulate another quantity of the motor unit by

  example its charge (filling), the mass of air supplied, the torque, the

  sance, etc. Correspondingly, also in such control concepts, a setpoint is defined which is adjusted by an action

  of regulation. The procedure described below using a set value

  a speed of rotation is applied according to other examples of reali-

  sation to other setpoint quantities.

  In such regulators, the slow starting or moving of the vehicle can lead to rotational speed collapses

  and, in the extreme case, stalling the engine. The reason for this behavior-

  ment is the lowering of the idle speed for consumption reasons. In addition, even the disturbing quantities of the clutch torque produced when the clutch is closed produce, in this operating state, annoying oscillations of the bodywork considerably deteriorating the comfort of movement. These effects occur in particular in the case of automated gearboxes and in

  internal combustion engines with direct petrol injection.

  As is known according to the state of the art mentioned in the preamble, in current solutions a torque reserve is adjusted to make the establishment of torque more dynamic in an internal combustion engine. This is why the rapid torque variations are first of all compensated by the reserve of torque obtained by

  ignition angle adjustment. As the statistical torque reserve in-

  has consumption drawbacks due to the deterioration of the yield, and that it cannot be increased in any way by necessarily delaying the ignition angle for this because of the limit of the ignition angle or the limit of the lambda value, the clutch will not be able to absorb greater torque demands so that a rotation speed collapse occurs at start-up. This is amplified in automated gearboxes (ASG) or gearboxes

  gears with automatic clutch. The reason is that the couple of displa-

  Slow cementing in automatic gearboxes (ASG) is applied when the brake is released. The disturbing torque thus occurs as soon as the accelerator pedal is released. The idle speed regulator must absorb this

  disruptive torque. In the case of manual gearboxes, the

  Marking is generally done by depressing the accelerator pedal. The-

  conductor demand thus given is greater than the torque lost by the internal combustion engine. The excess torque exists in these conditions from before the clutch closes, which improves

  absorption of the torque demand by the clutch.

  According to the invention, thus depending on the transition from the state of

  the clutch fully open in the regulated clutch state or in

  the pre-setting of the set value by the no-

  the setpoint speed and / or the torque reserve will be

  increased without delay. This brutal increased regulation deviation-

  ment by the regulator causes the control quantity of the actuating element and thus the controlled quantity to be increased in time

  to compensate by regulation the clutch torque at the brake point

  swim. This is especially true for filling cylinders, increased to

  time by opening the choke valve early enough. Detection

  tion of the passage from the engaged state is done using the clutch stroke, for example using a manual switch using the stroke of the

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  clutch pedal. The clutch stroke can also be detected by

  using other moving parts of the clutch. The increase in vi-

  rotation or torque of the drive unit during slipping of the clutch has, in addition, as a starting aid, the advantage of lowering the tendency of the body to oscillate during movement

  slow. In this operating state, the clutch is generally equal

  while skating. The excitation frequency, increased due to the rele-

  The speed of rotation significantly decreases the amplitude of the oscillation because the excitation is outside the resonance range.

body review.

  This increase is canceled when leaving the operating state with the clutch slipping (towards the open clutch or the closed clutch). Compared to a static elevation, the limited elevation

  over time while the clutch slips, does not increase the con-

  summons when the clutch is open. In addition, poor efficiency is avoided (delay of the ignition angle for a homogeneous mode X, = 1) with the clutch open because the torque reserve can be reduced outside of this operating state, especially at idle. If the clutch is completely closed, the rise in the nominal value is suppressed

  or from the torque reserve or preferably it is temporarily filtered.

  A preferred embodiment of the process presented

  above will be described using the flowchart of Figure 2. This computer

  gram outlines a calculator program run in inter-

  predefined time intervals preferably as a function of the speed of rotation (speed). In the first step 100, the following characteristic quantities are introduced: actual rotational speed Nist and clutch race Skup. Then in step 102, using the clutch stroke, it is checked whether the clutch is open (disengaged). This can be seen, for example, in that the Skup clutch stroke is compared to a predetermined limit value and if it is exceeded up or down, it is assumed that the clutch is open. If so the clutch is

  open, it is checked in step 103 if a FLAG coordinate system has been set to state 1.

  This mark (flag) is set to the state if the step is recognized for the first time.

  wise from the clutch open to the clutch closed or vice versa. If the re-

  father is at state 1 this means that the first time after the transient state, the clutch was considered to be open so that in step 104 the flag is set to the value 0; according to step 105, the set speed polur_! e operating mode with slip of the clutch is controlled, at the predetermined set value Nsoll2, to pass to the value Nsoll1, according to a predefined time function. The same remark applies to the operating state with the clutch slipping, for the increased torque reserve. If the flag is not set to state 1 (step 103), then in step 107 the preset value Nsoll is preset, the setpoint Nsolll provided for true idling and the reserve RES1 provided for real slow motion. These values depend on

  operating parameters according to a preferred embodiment

  tiel. After step 107, in step 106, the output signal of the idle speed regulator DMLLR is determined according to the indication of the predefined regulation strategy, on the basis of the selected reference value Nsoll thus

  than actual Nist value; by an appropriate filling order

  wise and from the ignition angle, the preset torque reserve RES1 is adjusted.

  If in step 102 it was found that the clutch was not open, it is checked in step 108 if the clutch is closed. This is done by using the clutch stroke, which is compared to a second limit value, the excess of which towards the bottom or up makes it possible to assume that the clutch is closed. If the clutch is closed, in the step, it is checked whether a FLAG flag has been set to the value 1. This flag is set when a passage from the open clutch to the closed clutch is detected for the first time or vice versa (see step 118). If the flag is set to 1, this means that the first time after a transient state, we

  detected the clutch closed so that in step 112 we put the dra-

  skin at the value O and in step 114, the target speed is controlled to change it from the target value Nsoll2, predetermined for the operating state with clutch slip to the value Nsolll, according to a function of preset time. The same remark applies

  for the torque reserve which has been increased in the operating state

  clutch slipping. Step 114 is followed by step 106.

  If step 110 showed that the flag was not up

  their 1, this means that the operating state of the vehicle is outside the range corresponding to the slip of the clutch; thus, according to step 116, the values RES1 and Nsoll1 are predefined as setpoints for the idling control or as a reserve, according to step 104. Then we

  go to step 106 in which, when the regulator is active, it is calculated

  outputs the idle governor output signal and if provided,

freeze the torque reserve.

  __If step S108 showed that the clutch was not closed, it is in the slipping state. This means that in step 118 we put the

  FLAG flag at value 1 and according to step 120, the rotational speed is set

  setpoint Nsoll, suddenly at the increased value Nsoll2 provided for this operating state. The same remark also applies to the torque reserve which is set to the value RES2. Then there is step 106 consisting in calculating the output signal of the regulator or in adjusting the torque reserve. After step 106 the program ends and it will be

  traveled again during the next time interval.

  FIG. 3 shows the operation according to the method described above using chronograms. FIG. 3a shows the chronogram of the setpoint speed of rotation (solid line) and of the

  actual rotation speed (broken line). Figure 3b shows the chrono-

  gram of torque reserve while Figure 3c shows the stroke

Skup clutch.

  The presentation corresponds to a vehicle with automatic gearbox (ASG) or automatic clutch. The vehicle is

  first of all really idle. Until now TO we have set the speed

  reference rotation size Nsolll and the reserve RES1; the clutch is

  open and the actual rotation speed Nist is regulated on the speed of ro-

  set point. At the moment TO we leave the open state of the clutch and

  the clutch is slipped. This means that at the time TO, both the re-

  serve (figure 3b) and the target speed (figure 3a) are increased

  brutally lied to. At time T1, it is recognized that the clutch is closed, which leads to the corresponding times according to FIGS. 3a and 3b to regulation over time for the increased values. As the

  shows figure 3a (dashed line) if we give up the described measure, we

  rises in under speed when the clutch starts to slip

  what the idle speed governor could regulate diffi-

  cleverly. Contrary to this, by applying the procedure described above

  above, the idle speed is increased; for that you need

  note that at time T1, the speed control is re-

  taken by the accelerator pedal because the vehicle starts. This allows

  to have a comfortable start without going under-regime.

  In general, during the period of the state of operation

  actuation corresponding to the slipping of the clutch, a set value is increased (torque reserve and / or set value; set speed of rotation) -par. compared to. la_valeur corresponding to another operating state (clutch open and / or closed). In an example

  of realization this increase is done only compared to the truth-

  ble idle (clutch open), because when the clutch is closed, there is a

another increase in value.

  The operating state "clutch slip" is first of all not recognized for the clutch stroke but is obtained provisionally. This means that if the clutch stroke leaves the value corresponding to the fully open clutch, it is estimated that the clutch is already slipping. This has the advantage that the rise in the set value (suddenly increased regulation deviation) or an increase in the torque reserve can be adjusted by the slow air path because at this time the clutch does not transmit any

  torque (disturbing quantity for idling control).

  The increase in torque or the torque reserve will then be noted via the air path (slow torque path) and represents a torque preselection for the moment at which the clutch stroke reaches the slip point. . Before reaching the slip point, the excess torque will be eliminated by adjusting the ignition angle delay (fast torque path) (idle control). At point

  skating, the torque can be adjusted quickly to compensate for the large

  disturbance of the clutch torque via the fast torque path (setting the ignition angle in the direction of advance). Advantage of this

  control: the torque reserve with poor efficiency by a re-

  late ignition angle only works as long as the clutch shifts

  from the open state to the skating point.

i1

Claims (7)

  1) Method for controlling the drive unit of a vehicle, according to which a control signal is generated as a function of a setpoint quantity, sign aLqui controls at least one actuator influencing an output quantity of the drive unit, the nominal value being influenced as a function of the state of the clutch, characterized in that for the duration of the operating state corresponding to the slip   of the clutch, the nominal value has an increased value compared to   port at its value in at least one other operating state.   2) Method according to claim 1, characterized in that   the nominal value is a nominal value, preferably a vi-   setpoint rotation speed, setpoint torque, setpoint power, setpoint filling or setpoint air mass   and / or a torque reserve to be set according to the ignition angle.   3) Method according to any one of the preceding claims,   characterized in that the clutch slip operating condition is determined from the clutch stroke, or if the clutch stroke leaves the value "full opening".   4) Method according to claim 3, characterized in that   the clutch stroke is determined by measuring the stroke of the   clutch plate or by measuring the stroke of another moving part of the clutch.    ) Method according to any one of the preceding claims,   characterized in that after leaving the slip state of the clutch, the quantity is regulated   setpoint increased to decrease it according to a pre-time function   determined, in particular a filter function from the increased value lied.   6) Method according to any one of the preceding claims,   characterized in that the control quantity is determined by an idle speed regulator, which determines the control quantity as a function of   rotation speed _ setpoint and _ actual rotation speed.   7) Method according to any one of the preceding claims,   characterized in that the torque reserve is adjusted by increasing the filling of the engine to   internal combustion and delaying its ignition angle.   8) Control unit of the motor unit of a vehicle comprising   a control unit which, depending on a target variable, manages   generates a control signal for an actuator influencing a large   deur of output of the driving unit, and which determines the operating state of a clutch of the driving unit and modifies the quantity of instruction according to the state of the clutch, characterized in that   the control unit determines the slip state of the clutch and   during the duration of this operating state increases the con-   sign in relation to its value in another operating state.