FR2727720A1 - METHOD AND DEVICE FOR CONTROLLING THE SLOWDOWN OF AN ENGINE GROUP - Google Patents

Abstract

a) The invention relates to a method and a device for controlling the idling of a motor unit. b) A method of controlling the idle speed of an engine unit with at least one electrically controlled adjustment element influencing the power of the engine unit, and which is actuated in the direction of adjusting a predetermined idle speed of rotation, this adjustment of the idling speed of rotation being made to comply with a predetermined magnitude of the battery voltage, method characterized in that the value to be observed of the battery voltage is fixed at a value existing in an operating state at during which the battery charges with certainty.

Description

"Method and apparatus for controlling the idling of a power unit"

  STATE OF THE ART: The invention relates to a method and an idle control device of a motor unit with at least one electrically controlled adjustment element influencing the power of the power unit, and which is actuated in the

  direction of setting a predefined idle speed

  completed, this adjustment of the idling speed of rotation being made to respect a predetermined quantity of the

battery voltage.

  Such a method or device is already known.

  tif according to DE 38 32 727 Al. In slow motion, it controls the idling speed of the motor group

  for the battery voltage to be regulated on a

  their predetermined. For this, the voltage level is maintained at that of the battery by the appropriate choice of the

  characteristic of the idling speed to be adjusted in

  terminating this voltage by the voltage of the battery.

  This characteristic curve leads to a setting such as

  idle speed of rotation than the voltage of the bat-

  is set to a predetermined fixed set point

  born. It has been found that the voltage level of the battery depends on tolerances of the seizure of the battery voltage as well as oscillations of the regulating voltage, for example due to the summer and winter operation of the generator. Therefore, the known procedure of charging a battery by the generator can not be guaranteed in

  all modes of operation during idle.

  Therefore, the present invention aims to create means for controlling the idle of a group

  engine eliminating the disadvantages mentioned above.

  For this purpose, the invention relates to a method of

  defined above, characterized in that the value

  to respect battery voltage at an existing value at an operating state in which the

battery is charging with certainty.

Advantages of the invention:

  The means of the invention ensure that

  lenti and in an operating mode close to idle, the generator or the alternator ensures a sufficient charge of the battery. In addition, advantageously, the level of

  the voltage at which the battery is charged is rendered indepen-

  tolerance of the detection of the battery voltage and the variations of the regulating voltage of

the generator.

  It is particularly advantageous to adapt the target voltage to which the battery is charged, to the

  voltage in the corresponding operating range

  at high rotational speeds, because it can be assumed that at this time the generator is supplying the setpoint voltage and that the balance of the battery charge can be

  respected regardless of the electrical constraints.

  In this operating state, the battery charge

  guaranteed even when all users are connected

kets.

  According to other advantageous features of the invention,

  - the value to be respected of the voltage of the battery

  is an existing value at high speeds of rotation.

motor.

  the value to be respected of the battery voltage is obtained from the measured value of the battery voltage when the speed of rotation of the motor exceeds

  a predetermined limit rotation speed.

  the measured value of the battery voltage is compared with a reference value and, by integrating the difference between the reference value and the actual value of the battery voltage, a value of

  idle speed of rotation, of setpoint which is re-

  in the context of rotational speed regulation

slow motion.

  - during the starting phase of the engine, there is no

  has no regulation of the battery voltage on a

their predetermined.

  The invention also applies to an idle control device of an internal combustion engine with

  using a control element with an electric control

  influencing the power of the drive unit, and which is actuated in the direction of adjusting a rotational speed

  predetermined idle speed, this adjustment of the rotation speed

  idling to respect a pre-determined size.

  determined the battery voltage, characterized in that the value to be respected of the battery voltage is set to an existing value for an operating state in which the battery is charging.

for sure.

  Drawings: The present invention will be described hereinafter at

  using the embodiments shown in the drawings.

  sins, in which: - Figure 1 shows a preferred embodiment of an idle control device for carrying out the method of the invention,

  - Figure 2 shows by a flowchart, the

  1 of the invention in the form of a computer program; FIG. 3 shows flowcharts of curves characteristic of the speed of rotation and the voltage

  battery illustrating the means of the invention.

  Description of the examples of realization:

  FIG. 1 shows a control unit 10

  connected by an output line 12 to an adjusting element 14 which adjusts the idle preferably by adjusting the throttle valve 18 fitted to the air intake pipe 16 of the internal combustion engine. An input line 20 connects the control unit 10 to a measuring element 22 to

  detect the battery voltage UB. Another line of

  trea 24 connects the control unit 10 to a measuring element 26 detecting the rotational speed of the motor. The battery voltage is generally evaluated by detecting the supply voltage of the control unit. Thus, the measurement of the voltage of the battery is tainted with power loss, unknown, characteristic of each battery and resistance of passage whose influence is reduced or

  eliminated by the means of the invention during the

  the battery voltage. In addition, there are

  input lines 28 to 30 connecting the control unit 10 with

  measuring equipment 32-34 and detecting other

  operating meters of the engine or vehicle such as engine temperature, user status

auxiliary or other.

  The input line 20 leads into the communication unit

  10 to a comparator 36 otherwise related

  line 38 from a memory element 40. The element

  memory 40 is connected to line 20 via line 42 and via a switch 43. The output line 46 of comparator 36 is connected to a switching element 48 whose second input is connected to a line 52 starting from the memory element 50. The output line 54 of the switching element 48 leads to a

  integration element 56 whose output line 58 is

  linked to an element 60 containing in memory a table or a characteristic curve. The output line 62 of the element

  led to a setpoint generator 64 receiving

  front lines 28-30. The exit line 66 of

  the element 64 leads to another comparator 68 whose se-

  conde line of entry is the line of entry 24. The line of

  output 70 of the comparator 68 is connected to a control unit

  72 whose exit line is line 12.

  Line 24 is connected by line 74 to a threshold stage 76 whose output line 78 leads to a

  switching element 80. The switching element 80 re-

  a line 84 of a first memory element 82 and a line 88 of a second memory element 86. The output line 90 of the switching element 80 serves to adjust the integrating constant of the integrating element. 56. A line 92 connects the line 78 to the switching element 48 to control it. The line 44 connects the line 92 to the switching element 43. The switching elements 43, 48, 80 are switched independently of the speed of

  rotation of the motor. Below the rotational speed threshold

  predetermined by the threshold stage 76, the switches

  occupy the positions represented in solid lines; au

  above the speed threshold, they occupy the position

  sition represented in broken lines. The regulator of

  idle is active according to a preferred embodiment

  when the engine is idling or running

  close to idling, especially when the accelerator pedal

is released.

  At low idle speed, currently common, it can happen that the battery is discharged, if too many electrical users such as heating a seat, heating the rear window and projectors work. To avoid this discharge, idle speed

  case where the battery voltage is too low.

  For this, according to a preferred embodiment

  1, the battery voltage UB detected by the measuring element 22 is preferably applied after a filtering of the signal, to the comparator 36 to be compared with a setpoint value UBcons of the

  battery voltage, stored in the memory element

  40. The difference between the setpoint and the actual value of the battery voltage is transmitted by the switching element 48 closed at low speeds.

  of rotation, to the integrating element 56 which ensures the

  gration. The output signal of the integrating element 56

  thus constitutes a measure of the load balance of the bat-

  series. This load balance is converted according to characteristic curves or the table obtained experimentally in element 60 into a speed reference value.

  idle rotation; this value is applied to the

  setpoint 64. The latter deals with the value of

  their rotation speed setpoint dependent on the

  battery voltage and rotational speed values.

  setpoint dependent on the operating parameters according to the procedure known from the state of the art to provide a value representing the rotational speed at

  adjust. This value is applied to comparator 68. This

  it compares the speed of rotation of setpoint with the vi-

  real rotation speed and transmits the regulation deviation via the line 70 of the control unit 72 of

  preferably a regulator with proportional characteristics

  the, integral and / or differential. This regulates the adjustment element 14 in the direction of the approximation of the

  actual rotation speed at the speed of rotation of

sign.

  The integrating element 56 cooperates with the

  predetermined integration by the memory element 82. When the rotational speed of the motor exceeds the predetermined threshold, the threshold stage 76 generates a corresponding signal. In the preferred embodiment, it has proved advantageous that there is a rotation speed threshold of the order of 3000 rpm. The signal from the floor to

  threshold 76 switches the switching elements 80, 48 and 43.

  The integration means 56 integrates in this operating state

  according to the recorded integration constant

  in the memory element 86 and which in the example of real-

  preferred embodiment is of greater amplitude than the constant recorded in the memory element 82. At the

  regulation deviation, at rotational speeds

  the integrating element 56 receives by the switching element 48 a value -A preferably -1

  from the memory element 56 and transmitted by the

  This causes the integration element 56 to receive a negative regulation deviation, that is to say a regulation deviation giving a battery voltage.

  greater than the set point. As a result,

  integrator 56 reduces its integration status or its

  exit signal, which leads to a reduction in the

  set rotation speed dependent on the battery voltage.

  In addition, at high rotational speeds,

  that the rotational speed of the motor detected by the measuring element 26 exceeds the threshold predetermined by the element 76, the switching element 43 is closed and the voltage of

  the battery is supplied to the memory element 40, for example

  a low pass filter. In the memory element, we

  permanently register the UB voltage of the battery at high speeds. When overtaking

  the threshold of the speed of rotation, the element of

  tation 43 opens, the applied battery voltage is

  registered and serves as a set value for the

  regulation of the battery voltage.

  In contrast to the state of the art, if the set value of the regulation of the battery voltage does not use a fixed value but the value of the voltage of the existing battery at high rotational speeds. This threshold speed of rotation is to be chosen so that at this speed of rotation, the generator can the case

  to provide its maximum current. In this state of functioning

  tion, the battery is surely charged by the gener-

  even if all users are connected. In addition, in this operating state, the supply voltage of the control unit used as a measure of the voltage

  battery is maintained by the regulator of the

  in a very safe way to the predetermined value (eg 14 V) even if the battery is discharged. In a preferred embodiment, a threshold speed of rotation of 3000 T / min has proved to be interesting. In

  adjusting the set point of the bat-

  the voltage drops specific to the vehicle are

  which exist between the battery and the control unit, which improves the regulation of the voltage of the

idle battery.

  If the engine is running at rotational speeds

  tion, the element of integration is slowly

  56 with the time constant inscribed in the memory element 86, because during this time, the generator is able to charge the battery again and it is no longer

  necessary to increase again the speed of rotation

  idle when you return to idling. In addition to the illustrated embodiment,

  makes the battery recovery time after the

  motor, regulating the voltage of the battery

  begins only after a predetermined waiting time.

  This waiting time according to the preferred embodiment

  tiel is of the order of 20 to 30 seconds.

  Next to the embodiment shown for detecting

  the battery voltage, in other examples of

  advantageous embodiment, it is possible to detect the

  the battery at predetermined detection times

  born during engine operation at speeds of

  high rotation and register by choosing as

  their setpoint the battery voltage preferably the

  last updated value. In other examples of

  For example, a previously measured value of the battery voltage or an average value of the measured values of the battery voltage can be used.

  previous, as a new setpoint.

  FIG. 2 shows a flowchart of a preferred embodiment of the method of the invention in the form of a computer program. After starting the program part, during a first step 100, it is checked whether the starting phase of the combustion engine

  internal ended. This is done according to a

  driver who starts when exceeding a starting rotational speed, determined; the described function is released

  when the counter exceeds a predetermined counting state

  born. When the internal combustion engine is in the starting phase, according to step 102, the integrators and memory elements are initialized to the predetermined values and

  the program part ends. When the function de-

  is released, in step 106, we record

  the operating parameters to be processed, such as the voltage

  UB battery voltage, the speed of rotation of the Nreel motor, as well as other operating parameters by which the idle speed set point value is set. Then, in the interrogation step

  106, it is checked whether the rotational speed of the motor de-

  passes a predetermined limit No. If yes, the motor is running at a high speed and the set point of the voltage of the

  drums. Then, in step 108, we set the constant of

  ILBZ integration of the integrator 56 at the value II, the AUB regulation deviation at the value -A preferably -1

  and the measured battery voltage UB at the value of

UBcons.

  Then, in step 110, the load balance of the LBZ battery is calculated by integrating the regulation deviation according to the ILBZ integration constant. Yes

  during step 106, it has been found that the motor does not rotate.

  is not generated at high rotational speeds, according to step 112, the ILBZ integration constant is set at the value 12. The control deviation AUB is formed from the difference of the stored setpoint value UBcons and the voltage measured battery UB. Then, the load balance LBZ is calculated in step 110. In the following step 114, the set value of the idling speed NconsB depending on the battery voltage is determined according to the load balance LBZ by a curve

  characteristic of association, obtained experimentally

  mental, this curve being preferably linear. Then, during step 116, the rotational speed of

  idle, setpoint Ncons depending on the speed of rotation

  of idling, depending on the voltage of the load and

  if that other operating parameters according to characteristic curves, characteristic fields or tables. Downstream of step 116, in step 118, during the idle operating mode, the idle speed of the setpoint is controlled by operating the adjustment element 18. The program part

then ends.

  Figure 3 explains the procedure according to the invention.

  with time diagrams given as an example. In Figure 3a, there is shown a signal characterizing the idle state of the internal combustion engine. At the moment,

  this signal goes from the idle state to the non-slow state.

  ti while at time t3, there is transition from the idle state to the idle state. Figure 3 shows the curve of the rotational speed (solid lines) as well as that of the nominal rotation speed (NconsB) (dashed line curve) as a function of time; FIG. 3c shows the curve of the battery voltage UB (solid line) as well as the target battery voltage (UBcons, dashed line curve) as a function of time. Until moment to, the battery voltage

  is regulated on the value UB1. This is achieved by

  setpoint rotation speed NconsB. At instant to, the internal combustion engine leaves idle. The rotational speed of the engine increases as shown in Figure 3b. At time t1, we exceed the value of the limit speed of rotation No. Between the times t0 and t1, we assume

  that the battery has been charged due to the speed of rotation

  high engine speed; the battery voltage is thus slightly raised. The set value of the battery voltage UBcons remains constant, since no adaptation phase is provided because of the speed of rotation that is too low in this time range. On the contrary, speed

  idle rotation, NconsB set point between

  tants to and t1 is calculated according to the deviation

  be the set point and the actual value of the voltage

drums.

  Due to the increase of the deviation between the real voltage and the target voltage of the battery, this results in a decrease in the rotational speed

  setpoint between times to and t1. At the instant t1

  the speed of rotation of the motor exceeds the threshold No, begins the phase of adaptation of the set value of the battery voltage. Due to filter constants

  possibly used, the reference value of the battery

  UBcons before the moment t2, the present value of the

  UB2 battery voltage. At time t2, the speed of rotation

  the motor goes down below the limit value No, which leads to a storage of the value of the voltage of the battery existing at time t2 as a value

  deposit. Between instants t1 and t2, the value of

  sign of the battery voltage UBcons is close to the value of the measured battery voltage UB whereas, as a result of the planned decrementation of the value of the load balance, there is a further decrease in the value of the rotation speed of setpoint NconsB. At time t2, when the speed of rotation is exceeded

  the setpoint of the voltage of the battery

  is recorded and the load balance is calculated.

  the deviation actually applied between the value of

  and the actual value. In this case between times t2

  and t3, the set point and the actual value of the

  battery voltage does not differ, so that the setpoint of the rotation speed of the NBcons motor remains

  the value at time t2. At time t3, the engine with com-

  internal bustion goes back into idle mode, so that the speed of rotation of the Nreel engine is regulated

  on the predetermined setpoint NconsB.

Claims (5)

R E V E N D I C A T IONS   1) Slow motion control method of a group   motor with at least one electrically controlled adjusting member   the power of the power unit, and which is actuated in the direction of setting a predetermined idle speed, this idle speed adjustment being to respect a magnitude of   predetermined voltage of the battery voltage, characterized by   se in that one sets the value to be respected of the tension of   the battery to an existing value to a functioning state-   during which the battery is charged with certainty.   Method according to claim 1, characterized   in that the value to be respected of the voltage of the bat-   is an existing value at high speeds of rotation. motor.   3) Method according to one of the preceding claims   characterized in that the value to be respected of the   battery voltage is obtained from the measured value   the battery voltage when the speed of rotation is   motor exceeds a predetermined limit rotation speed.   4) Method according to one of the preceding claims   characterized in that the measured value of the battery voltage is compared with a set value and   by integrating the difference between the value of   and the actual value of the battery voltage, we de-   a value of the idle speed, which is set as part of a slow idle speed.   5) Method according to one of the preceding claims   characterized in that during the start-up phase   motor, there is no regulation of the battery voltage.   on a predetermined value.   6) Idle control device of an internal combustion engine by means of an electrically controlled adjustment element influencing the power of the drive unit, which is actuated in the direction of adjustment   of a predetermined idle speed of rotation, this   idle rotation speed to a predetermined magnitude of the voltage of the   battery, characterized in that the value to be   the battery voltage is set to an existing value for an operating state in which the battery is charging with certainty.