FR2669964A1 - SYSTEM FOR CONTROLLING AND / OR REGULATING AN INTERNAL COMBUSTION ENGINE. - Google Patents

Abstract

a) System for controlling and / or regulating an internal combustion engine, b) system characterized in that in partial ranges of signal values no fault check is carried out. c) the invention relates to systems for the control and / or regulation of internal combustion engines.

Description

System for controlling and / or regulating a combustion engine

  The invention relates to a system for controlling and / or regulating an internal combustion engine, at least as a function of signal values which represent an operating parameter of the internal combustion engine and / or the motor vehicle, and which are determined by a device enabling the detection of these operating parameters, while faulty operations of these devices are avoided from the values of the signals delivered by them.A system of this type is known from document DE-OS 36 21. The system described in this document for the control and / or regulation of an internal combustion engine, has at least one measuring device for detecting an operating parameter of the internal combustion engine and / or the motor vehicle, parameter according to which the internal combustion engine is controlled and / or adjusted.This operating parameter relates in particular to the position of an organ An identification of a malfunctioning operation for the measuring device takes place from the signal values supplied by it, which represent the operating parameters, in accordance with the present invention. comparing these signal values with values

predefined limits.

  Difficulties arise when the detector used to capture an operating parameter of the internal combustion engine and / or the vehicle, comprises in its range of signals, partial ranges and which are characterized by a transmission or production of altered signals and / or incomplete Such problems occur for example because of pollution In potentiometers for example, it is formed as a result of the friction on the track of the resistance on partial areas of its range of displacement, difficult to conduct areas This is particularly the case at the points of inversion These stains result in a high resistance of passage between the track of the resistor and the cursor and thus also, by a signal value of false operating parameters This has the consequence, in surveillance systems known, an announcement of default and therefore a

  failure of the system equipped with the measuring device.

  The purpose of the invention is therefore to indicate the arrangements which guarantee a large operational safety and a wide availability of a control and / or regulation system of a

internal combustion engine.

  This object is achieved in that for the control of the defects of the measuring device detecting the operating parameters, a control method is implemented which does not perform any control within predefined partial areas. DE-OS 35 10 173 discloses a monitoring device for an electronically controlled throttle valve in a motor vehicle, in which device is connected in particular to the accelerator pedal, a measuring device which, in a exemplary embodiments, is constituted by a position indicator potentiometer and a monitoring potentiometer The value of the signal delivered by the position indicator potentiometer is compared in a logic unit with the values determined from the signal of the monitoring potentiometer A the Using the magnitude of the position indicator potentiometer signal, compared to the values of the signals of the monitoring potentiometer, the operation of the device is controlled This procedure also has the aforementioned drawbacks. In addition, the document DE-OS 40 04 083 discloses a system for controlling and / or regulating an internal combustion engine as a function of signal values, which represent a parameter of operation of the engine with internal combustion and / or motor vehicle This system comprises a device for the detection of this operating parameter Defective operation of this device is deduced from the values of signals delivered by it Within predefined partial ranges of the signal range of this device, the control of faults is carried out with

reduced sensitivity

  An advantage of the procedure according to the invention resides in the fact that a control method is used which does not carry out any control in partial areas. These partial zones are characterized by an altered transmission or production of signals. or incomplete, for example as a result of a resistance of passage increased by the friction between the track of the resistor and the cursor of a potentiometer It is thus, on the one hand possible to recognize the defective operation, actually involved, the detector and yet effectively avoid a shutdown of the entire system due to supposed faulty operation

indicated above.

  Other advantages of the invention are characterized in that the operating parameter represents the position of at least one adjustment mechanism influencing the power of the internal combustion engine and / or of an operating element that can be actuated. by the driver; in that at least two value ranges are formed, while within one there is a fault check and within the other no fault check takes place, in that, for the devices for detecting operating parameters, these are detectors and / or switches, in that for these detectors there are potentiometers, in that the predefined partial ranges are determined by transmission and / or detection of altered and / or incomplete signals, in that in the vicinity of the potentiometer inversion points, no fault control takes place, in that when the potentiometer is in the vicinity of these reversal points, no control

fault is not performed.

  The invention will be explained below with the aid of the exemplary embodiments shown in the accompanying drawings. FIG. 1 is a block diagram 1 of the system in the example of a diesel electronic control system, FIGS. 3 specify the procedure according to the invention, in the form of a characteristic curve diagram and a

functional diagram.

  FIG. 1 shows an adjustment member 10 determining the power of an internal combustion engine, not shown, this member being for example a control rod for controlling the quantity of fuel supplied to the internal combustion engine or a valve In addition, an operating element which can be actuated by the driver, for example an accelerator pedal, is designated by the operating element 20. is mechanically connected to several detectors 30, 40 These detectors 30, 40 deliver signals to a measuring device 50 for the detection of the operating parameters The measuring device 50 for the detection of the operating parameter, is part of a device of command which is preferably realized in the form of a calculator But it can also be realized at

means of discrete circuits.

  This control apparatus further receives signals from a detector 70, which indicate the position of the regulator 10 determining the power. This detector can, in a particularly advantageous way, be provided as a dual detector so similar to the detectors 30 and 40 In this case, a measuring device 55, which is constituted in a manner corresponding to the device of

  measure 50, receives the operating parameters.

  Other detectors 80 detect characteristic quantities of the operation, such as for example the speed of rotation As a function of the signal values which represent the operating parameters of the internal combustion engine and / or the motor vehicle, as well as the values of the signals of the other detectors 80, the control apparatus 100 calculates signals for the control

  and / or the regulation of the internal combustion engine.

  These signals serve in particular to act on the organ of

  setting 10 determining the power.

  The detectors 30 and 40 detect the position of the element which is associated with them. In a particularly simple example of embodiment, this concerns, as regards the detector 30, a potentiometer, and as regards the detector 40, of a switch At the output of this switch, appear according to the position of the element,

two different signal states.

  Thus, the switch can be made so that the switch is closed at idle and open at full load In this case, there is at the output of the detector 40, a high voltage idle and out of idle, a lower voltage But it is quite possible that the switch is made so that at the output of the detector 40, there is a reduced voltage idling

  and, outside the idle, a high voltage.

  In another embodiment, two detectors 30, 40 are made in the form of potentiometers.

  be realized in the form of a double potentiometer.

  In this case, the mechanical connection is connected to the movable sliders of the potentiometers. The value of the

  signal is, in this case, taken from the sliders.

  The mechanical connection of the detectors means that a modification of the positions of the associated element 20 results in a corresponding modification of the signal value of the two detectors, so that each detector provides, as far as it is concerned, a value of signal representing the position of the associated element This is particularly the case when two detectors are made under

form of potentiometers.

  The detector 70 which indicates the position of the regulator 10 determining the power, is usually realized in the form of a potentiometer, for example in the form of a double potentiometer with

two conductive tracks.

  The operation of the arrangement according to FIG. 1 will be explained below. The measuring device 50 delivers the control device with signal values which indicate the position of the operating element 20. of an embodiment in the form of a computer, the analog signals of the detectors 30 and 40 are converted by

  through digital analog converters

  in numerical quantities, which is then

calculator 100.

  Depending on the position of the operating element 20, and possibly depending on other signals, the computer calculates a control signal

  for the regulator 10 determining the power.

  For these other signals, it can for example be the rotational speed signal. The calculation is carried out

  then depending on the output signal of the detector 30.

  The detector 40 serves only to monitor the

operation of the detector 30.

  However, it is also possible to use a mean value or a minimum value of the signal magnitudes obtained from the detector 30 and 40 for regulating the position of the power adjusting member. In this case, at least one of the signal magnitudes of one of the detectors is used for monitoring the operation of the other detector (s). On the other hand, if the detector 40 is in the form of a switch, then this detector is preferably used to prepare a detector. In addition, by comparing the two output signals, the ability of both detectors to

  The same goes for the detector 70.

  In addition to the functions of the control apparatus 100 shown in FIG. 1, this apparatus can still fulfill other functions, such as, for example, the determination of the instant of injection, the instant of ignition, the dosage of

  fuel and / or idle adjustment.

  FIG. 2 shows the characteristic curves as a function of the position of the two detectors shown in FIG. 1. The solid line curve shows the output signal UPWG of the detector 30 hereinafter referred to as a potentiometer, as a function of the angular position WFP of the accelerator pedal The output signal from the detector 40 hereinafter referred to as the idle gas switch, is indicated in dot lines. Below an angle W1, the idle throttle switch is closed, and above an angle W 2, the idle gas switch is

open.

  This is a possible connection of the idle gas switch It is also possible that below the angle Wl the

  idle gas is open and closed

  above the angle W 2 In the angular region between the angle W1 and the angle W 2, the switching state of the idle gas switch is not defined. This means that in this angular zone the idle gas can take two states The position of the switch then depends on what the idle gas switch was previously

closed or open.

  Six ranges of values for the signal of

  UPWG output of the potentiometer can be distinguished.

  In the case of the value range 1, it is a

  voltage which in normal operation does not intervene.

  The voltage range 2 corresponds to this voltage zone in which the transmission or the signal detection can be defective. This corresponds to the range of values obtained when the potentiometer is at its lower inversion point. value 3 characterizes the range of values in which the idle gas switch is usually closed Value range 4 indicates the range of values in which the position of the idle gas switch is not defined In the value range 5 , the idle gas switch is usually open The value range 6 is the value range in which the transmission or the signal detection may be defective, because the potentiometer is in the vicinity of its second

inversion point.

  The known fault monitoring devices only detect if the output signal is in the range 1, 2 or 3, and if at the same time, the idle gas switch is closed or if the pedal value indicator is in zone 5 and if the idle gas switch is open In such systems, it can then occur the case o especially for small or large angles, the detection of signals is defective This implies that for large angles or for small angles of the indicator of the value of the pedal, the conductive track is interrupted and at the output of the detector, there is a very low voltage

  which is in the value range 1.

  If the output signal of the detector 30 is in the value range 1, a fault is usually concluded. This has the consequence that an emergency running operation is initiated As after a very long operation of the internal combustion engine for very large and very small angles of the potentiometer, stains intervene

  very frequently, this case occurs very frequently.

  This has the consequence that during the running time of the internal combustion engine, there are more and more situations of defects or

  although strictly speaking, there are no defaults.

  Furthermore, in known systems, there is a plausibility query between the position of the idle gas switch and the output signal of the pedal value indicator for a wide angle of the value indicator of the pedal, the idle gas switch must be open For small angles, ie a small output signal, the idle gas switch must be closed This means that in the partial ranges 2 and 3, the idle gas switch must be closed, and it must be open in the partial ranges 5 and 6 In the partial range 4, the idle gas switch can take two positions Partial range 1 is excluded because the output signal of the value indicator of the

  pedal can not occupy this range.

he

  If there is then a query of plausi-

  when the pedal value indicator is within the partial range 6, and if there is an interruption on the conductive track, then the idle gas switch is open and the output signal of the pedal value indicator indicates a low voltage In this

  In this case, we conclude that the plausibility is not the fault.

  But strictly speaking, there is no fault because the idle gas switch is open and

  the pedal value indicator has a wide angle.

  Emergency operation is then

  primed, although there are no defaults.

  Similar problems arise when instead of the idle gas switch,

  uses another potentiometer that has a characteristic

  analogous output signal as the idle gas switch Such a potentiometer has as an output signal for small angles, a high voltage and for large angles a low voltage corresponding to the output signal of the idle gas switch such

  it is indicated in dotted lines in Figure 2.

  If in such a potentiometer, there occurs during operation, also deposits, there is at the output of the second potentiometer a low voltage although, because of its position, there should be a significant voltage If a question plausibility is then performed, we conclude the defect is identified so a defect although the value indicator of the pedal is fully able to operate emergency operation is not necessary in this case Thus, in the system known, states of emergency occur very frequently, although there is no critical operating condition This does not translate into an increase in the system failure rate. To avoid this, one proceeds as indicated in FIG. 3 In a first step 300, the position of the potentiometer is detected. An interrogation device 310 identifies the partial ranges in which the output signal is located. If the output signal of the potentiometer takes values that are in the partial ranges 1, 2, 4 or 6, a fault check is then performed and the control program ends in step 304 If, on the other hand, the interrogation device 310 recognizes that the output signal of the potentiometer is in one of the zones 3, 5 or 6, a control of

  the fault is in interrogation unit 320.

  A particularly simple embodiment of the invention provides that the interrogation device 310 only controls whether the output signal of the potentiometer is at a determined threshold below its maximum value or at a determined threshold above its minimum value This means that the potentiometer is in the vicinity of these inversion points If this is the case, there is no fault control Thus, no fault control takes place in the vicinity of the dots. inversion of the potentiometer The threshold is usually 10%

  the maximum value of the output signal.

  This is particularly advantageous in that, a plausibility check of the output signal of the potentiometer 30 with the output signal of the idle gas switch 40 is performed. If this interrogation unit 320 recognizes that the output signal of the potentiometer is not plausible compared to the idle gas switch, then a fault announcement is issued in step 330 This fault announcement can trigger a display that informs the driver of the fault

  It can also be expected that immediately

  Emergency operation is initiated. It is particularly advantageous that both measurements take place. If a fault situation is not recognized, the routine ends.

then at step 340.

  The method described is not limited to

  monitoring the pedal value indicator.

  It can be applied to all the devices making it possible to detect a characteristic quantity of the operation in which two detectors are mutually controlling each other for defects which are in particular applicable to the detector 70, which indicates the position of the detector.

  the element determining the power.

Claims (8)

  1. System for controlling and / or regulating an internal combustion engine, at least as a function of signal values which represent an operating parameter of the internal combustion engine and / or the motor vehicle, and which are determined by a device (100) for detecting these operating parameters, while faulty operations of these devices are avoided from the values of the signals delivered by them, characterized in that in ranges (1, 2 or 3) ( 4, 5, 6) partial values of   signals, no fault check is performed.   2. System according to claim 1, characterized in that the operating parameter represents the position of at least one adjusting mechanism (10) influencing the power of the internal combustion engine and / or an operating element   which can be operated by the driver.   3 System according to any one of   claims 1 and 2, characterized in that at least   two ranges (1, 2) of values are formed, while within one there is a fault check and inside the other, no control of fault occurs.   4. System according to any one of   claims 1 to 3, characterized in that for the   devices for detecting operating parameters, these are detectors (30) and / or switches (40).   5. System according to any one of   claims 1 to 3, characterized in that for these   detectors (30, 40), these are potentiometers.   6. System according to any one of   Claims 1 to 5, characterized in that the ranges   predefined partial values (5 and 6) or (1, 2, 4) are determined by transmission and / or detection   altered and / or incomplete signals.   7. System according to any one of   claims 1 to 6, characterized in that   neighborhood of the potentiometer inversion points,   no fault check has taken place.   8. System according to any one of   Claims 1 to 7, characterized in that when the   potentiometer is in the vicinity of these points   inversion, no fault check is performed.