EP1277940A2 - Method and device for the operation of a drive engine - Google Patents

Abstract

An adjustment value for an idling regulator, locks onto a resultant preset rating and changes by relying on engine RPMs or a time factor as an idling operation changes to a non-idling operation. Signals match vehicle speed (VFZG) and accelerator pedal position (PWG). These values are translated into a driver's torque requirement in a map of characteristics. This requirement is fed to an adjustment stage (102) to be corrected by a weighted torque loss (MKORR). Independent claims are also included for a device for operating a drive motor with a control unit and an idling regulator to match a driver's intentions and for a computer program with program code.

Description

State of the art

The invention relates to a method and a device for operating a drive motor of a motor vehicle.

In order to operate drive motors for vehicles, electronic ones are used Control systems used with the help of the the performance parameters that can be set on the drive motor depend be determined by input variables. Some of these electronic control systems work on the basis of a Torque structure, i.e. from the driver and, if applicable, from additional systems, like cruise control, electronic stability programs, Transmission controls, etc., are used as setpoints torque values specified for the control system, the from the control system considering other sizes in setting variables for the performance parameter (s) Drive motor are implemented. An example of one Torque structure is from DE 42 39 711 A1 (US patent 5 558 178).

To maintain engine operation takes over at known Control systems with the accelerator pedal depressed and low Speeds an idle controller the task of engine speed at a safe level for engine operation to stabilize. However, this idle controller is supposed to be the moment of the drive motor do not influence if at depressed accelerator pedal and higher engine speeds should be set according to the driver's request. The There is a transition between these two operating states to realize that the way the motor control works and driving comfort are influenced as little as possible. There is also an optimized integration of this transition function into a moment structure, which is independent of the respective The type of engine (petrol engine, diesel engine) should be aimed for.

Advantages of the invention

By connecting the idle controller component to the resulting one Target torque after coordination of Driver request torque and target torque of other control systems as well as through the detachment controlled depending on the size of the company of the idle controller contribution, it enables the idle control to optimally fit into a moment structure that can be used regardless of the motor type. torque structure and the replacement or reinstallation of the Idle controller when transitioning from idle to non-idle can therefore be carried out in the same way for all engine types become.

It is advantageously possible for gasoline and diesel engines the same (identical) structure for moment coordination including the activation of the idle control to enable. The contribution of the idle controller will in the same way for petrol and diesel engines Transition from idle to non-idle operation and / or vice versa affected.

A time-controlled detachment is particularly advantageous the contribution of the idle controller when the accelerator pedal is pressed. This is because after a limited time Transition process no change or influence the engine torque by idle controller more. In particular jumps in momentum that affect driving comfort and that through different physical Translation of the idle control torque via the transmission arise avoided.

Furthermore, the fact that no additional idle controller portion arises, the requirement to wheel torque constant translation changes, i.e. that before and the same wheel torque value is set after a gear change is.

The engine speed-dependent is advantageous in the context of an alternative solution Replacement of the idle controller fee. In a defined speed range above a speed threshold here too the desired property becomes more constant Translation changes achieved.

In a particularly advantageous manner, it is possible to have a double one Compensation of loss moments that are not for the drive of the vehicle are available through an existing one Pre-control of these loss moments and the idle controller to avoid. This is achieved through the activation the loss torque pre-control by weighting with the complement of the idle control weighting factor he follows. In other words, when the contribution is redeemed a corresponding (speed or time-dependent) regulation of the loss torque pre-control performed.

The influencing function of the Idle controller dependent on other operating parameters, e.g. Motor temperature, outside temperature, air pressure, etc.

Further advantages result from the description below from exemplary embodiments or from the dependent ones Claims.

drawing

The invention is described below with reference to the drawing illustrated embodiments explained in more detail. Figure 1 shows an overview of a control device for operation of a drive motor, while in FIG Flowchart a preferred embodiment of a torque structure in connection with the control of a drive motor is shown, provided it is with a view to the described Approach is important. Figures 3 and 4 show two preferred embodiments for formation a correction factor, with the help of which the idle controller influenced in the transition between idle and non-idle becomes.

Description of exemplary embodiments

Figure 1 shows a block diagram of a control device to control a drive motor, especially one Internal combustion engine. A control unit 10 is provided which as components an input circuit 14, at least has a computer unit 16 and an output circuit 18. A communication system 20 connects these components for mutual data exchange. The input circuit 14 of the control unit 10 become input lines 22 to 26 supplied, which in a preferred embodiment are designed as a bus system and via that of the control unit 10 signals are supplied, which are used to control the drive motor Represent the operating variables to be evaluated. These signals are recorded by measuring devices 28 to 32. In the example, such operating variables are one Internal combustion engine accelerator pedal position, engine speed, engine load, Exhaust gas composition, engine temperature, etc. About the Output circuit 18 controls the control unit 10 the power of the drive motor. This is shown in FIG Output lines 34, 36 and 38 symbolize via which the fuel mass to be injected, the ignition angle and at least one electrically operated throttle valve Adjustment of the air supply can be operated. About the illustrated Paths become the air supply to the internal combustion engine, the firing angle of each cylinder, the one to be injected Fuel mass, the injection timing and / or the air / fuel ratio, etc. is set. Further further control systems of the vehicle can be provided, the input circuit 14 default sizes, for example Transmit torque setpoints. Such control systems are, for example, traction control systems, vehicle dynamics controls, Transmission controls, engine drag torque controls, Speed controller, speed limiter, etc. In addition to these external setpoint specifications, including those a setpoint specification by the driver in the form of a driving request or a maximum speed limit are internal default values for the drive motor provided, e.g. the output signal of an idle control, a speed limitation, a torque limitation, Etc..

Correspondingly, with adapted output and input variables, the control system will also be equipped with alternative drive concepts, e.g. Electric motors used.

To maintain engine operation when not pedaling Accelerator pedal and low speed is an idle controller intended. This determines, for example, depending on the Speed deviation between a target and an actual speed using a specified controller strategy (e.g. proportional, Integral and / or differential component) one Contribution (e.g. torque change quantity or setpoint torque) that to the resulting target torque value for the drive motor is activated. In the preferred embodiment this intrusion is carried out as an addition. In other embodiments the idle contribution is e.g. normalized so that the connection is made by means of multiplication. The idle controller is connected to the resulting one Target torque, which is coordinated by the driver's desired torque and the target torques of other control systems, external and, if necessary, internal default values are formed. Thereby becomes an influencing of the wheel torque as mentioned above avoided by the idle controller, so that wheel torque constant Translation changes can be achieved.

Pressing the accelerator pedal is in the preferred embodiment a temporary process started, during the time-dependent idle controller contribution continuously is withdrawn to zero. In the preferred embodiment a factor is formed depending on the time, which starts with one after a given one has expired Time period takes the value zero and with the idle controller contribution is weighted (multiplied). After expiration the idle controller contribution is the specified time period Zero. When the accelerator pedal is released, if this is its idle position this factor is preferred Embodiment suddenly set to one to Idle regulators give the opportunity to maintain immediately of the engine operation. In other A time-dependent control is also exemplary here of the idle controller contribution, with the Factor increases from zero to one. The time periods for detachment and switching on the idle controller are preferred different, one when switching on the controller a shorter time period is selected than for the replacement.

An alternative solution shows a corresponding replacement of the Idle controller depending on the speed instead of the time. The idle controller contribution increases with increasing speed drove to zero, in the preferred embodiment the factor mentioned above corresponds to a speed-dependent Characteristic curve is formed. Here, too, is when sinking Engine speed a speed-dependent adjustment of the idle controller contribution according to the same or a different one Characteristic curve provided, the above-mentioned factor accordingly is formed.

Another alternative is that of the idle controller output signal maximum and minimum value limits assigned to which the signal is limited. The detachment or control is then manipulated by these limits realized, with e.g. the maximum value preferably time-dependent or speed-dependent on the Value zero is controlled, and / or the minimum value to the Value zero is controlled. The control is reversed method.

The flow chart shown in Figure 2 describes a Program of a microcomputer of the control unit 10, wherein the individual blocks of the representation of FIG. 2 programs, Represent program parts or program steps while the Connection lines represent the signal flow. It can the first part up to the vertical, dashed line in a first control unit, also there in a microcomputer, expire while the part in after that line a second control unit runs.

First, signals are supplied which correspond to the vehicle speed VFZG and the accelerator pedal position PWG correspond. These variables are in a map 100 in a torque request implemented by the driver. This driver request moment, which is a default size for a moment on the output side represents the transmission or for a wheel torque, one Correction stage 102 supplied. This correction is preferred an addition or subtraction. The driver request moment is determined by a weighted loss moment Corrected MKORR, which was formed in node 104 has been. In this is the supplied, by means of Translation Ü in the drive train and possibly further translations in the drive train on the output side of the gearbox Moment after the transmission, preferably a wheel torque converted Loss moment MVER weighted by a factor F3. The weighting is preferably carried out as a multiplication. The Factor F3 is in 106 from the accelerator pedal position representing Size PWG and possibly also the engine speed representative size NMOT formed.

The driver request MFA in this way becomes the moment coordination to form a resulting default torque MSOLLRES fed. In the example shown, a first Maximum value selection stage 108 is the maximum value from the driver's desired torque MFA and the default torque MFGR of a cruise control selected. This maximum value is to a subsequent minimum value stage 110, in which the smaller of this value and the target torque value MESP an electronic stability program is selected. The output variable of the minimum value stage 110 represents a torque variable output side of the transmission or a wheel torque size represents by taking into account the gear ratio Ü and, if necessary, further translations in the drive train converted into a torque size on the output side of the gearbox which is on the transmission input side or output side of the drive motor is present. This moment size is in one another coordinator 112 with the target torque MGETR one Transmission control coordinated. The target torque of the transmission control is formed according to the needs of the switching process. In the subsequent maximum value selection stage 114 the resulting setpoint torque MSOLLRES then becomes the larger one the torque values minimum torque MMIN and the output torque coordination level 112. The minimum moment is in a preferred embodiment from the Torque loss derived.

The moment coordination is only exemplary above shown. In other versions, one or the other other default torque not used for coordination or other default torques are provided, for example a moment of a maximum speed limit, one Engine speed limitation, etc.

The resultant formed in the manner described above Target torque is supplied to a correction stage 116 in which the target torque with the engine to apply, not that Corrected loss torques available becomes. The loss moments MVER are possibly in a weighting level 118 weighted with a factor F2. This is depending on the version constant (also 1) or depending on the company size, e.g. engine speed-dependent. The loss moments MVER themselves become the torque requirement in the addition stage 120 MNA of auxiliary units and the engine loss torque MVERL formed. The determination of these sizes is from the Known in the prior art, the torque requirement depending depending on the operating status of the respective auxiliary unit of characteristic curves or the like, the engine loss moments determined depending on engine speed and engine temperature becomes. The loss torque MVER formed in this way becomes then provided to correction stage 104, where a conversion of the torque loss using the known Gearbox transmission Ü as well as further translations in the Drive train on the output side of the gearbox on the plane the transmission output or wheel torque occurs.

The output of correction stage 116, which in the preferred Embodiment represents an addition is a default size for that to be generated by the drive unit Torque for the drive taking into account the inner Losses and for the operation of auxiliary units (e.g. Air conditioning compressor) necessary torque (indicated engine torque). This default torque is in a further correction stage 122 with the weighted in a correction stage 124 Output variable DMLLR of the idle controller corrected (preferably added). The weighting factor F1, with which the Output variable of the idle controller is included depending on speed and / or time, when leaving the Idle range the factor temporally or with increasing Engine speed decreases to zero. The default size is MISOLL then in 126 as known from the prior art in manipulated variables for setting the performance parameters of the drive motor implemented, in the case of a gasoline engine in Air supply, fuel injection and ignition angle, in the case a diesel engine in fuel quantity.

In addition to the time or the speed are in one execution further operating variables in determining the control or control of the idle control component is taken into account, e.g. Engine temperature, outside temperature, outside pressure, Etc.

With its contribution DMLLR, the idle controller intervenes in the direction of action after moment coordination (108 to 114) in the torque specification in which it corresponds to its output signal the resulting target torque MSOLLRES is corrected. The correction is complete in the idle controller area. When transitioning from idle to non-idle in 124 the idle controller output with a factor F1 weighted, which over time after pressing the Accelerator pedal or speed-dependent from one to zero. If the factor is zero, there is no idle controller component more activated. The idle controller itself can do this continue to be active according to the design and according to the speed ratios run to its limit or through Time control of the integral part, by zero enforce proportional and differential portion or Partially fixing the integral part to the current value or be stopped entirely. In the embodiment of Figure 2, the idle controller is further by the connection the loss moments MVER piloted in 116. This means that the idle controller only the deviations between pilot control values and the actual torque ratios corrects. In other embodiments this precontrol of the loss moments is missing, so that Idle controller the total loss moments and the demand adjusts the auxiliary units. There is an interim solution therein, in 118 the loss torque feedforward control by a factor To weight F2, which is complementary to the curtailment of the Idle controller contribution is raised. That means in that Dimensions by the weighting of the idle controller contribution in 124 this decreases, decreases by corresponding opposite Weighting the precontrol in step 118 increases this.

This is essential for the functioning of this arrangement Formation of the factor F1, which is the replacement and, if necessary, in analog How the idle controller contribution increases. A first solution is shown in FIG. 3. there the factor F1 is triggered by actuation of the accelerator pedal (signal PWG> 0) from its value one to Reduced value zero. An example is shown in Figure 3, in which the reduction is carried out linearly. In other versions, other time functions, for example exponential, step-like time functions, etc. used. The pedal is operated at time T0, after a certain predetermined period of time At time T1, factor F1 is then reduced to zero. This means a complete disappearance of the effect of the idle controller as part of the torque control. When the pedal is released, i.e. the drive motor returns back into idle mode, the idle controller part 1 in one embodiment again depending on time headed for its full value.

Instead of the accelerator pedal position alone is in other versions a combination of accelerator pedal position and speed or driving speed for determining the transition decisive. Another version leads the shown Procedure for operating the pedal via a specific one Measure beyond.

A second embodiment is shown in FIG. 4. there is a characteristic curve 150, which is the engine speed NMOT is fed. In this characteristic is the factor F1 plotted against engine speed. For speeds below the speed N1 is the factor 1, for speeds higher N2 it is zero. In the range between the speeds N1 and N2 a course of the factor F1 is specified, this with increasing speed drops towards zero. The illustrated is linear dependence between factor F1 and speed exemplary. In other versions there are different dependencies selected. In the preferred embodiment, N1 a speed that is just above the idle speed (e.g. 900 revolutions per minute) while the second speed N2 a higher speed of e.g. 1500 revolutions represents per minute. Depending on the engine speed The characteristic 150 becomes the value of the factor F1 read out, which then has the effect according to its size of the idle controller as part of the torque control shown weighted. The speed returns to the range the speeds N1 and N2 back, so the idle controller portion in one embodiment depending on the speed headed back to its full value.

The above embodiment, in which the detachment or Control of the idle controller contribution via weighting factors is exemplary. In other embodiments this is done by appropriate weighting of the controller parameters, e.g. of the integral part (where proportional and Differential component can be set to zero). A another way of realization is from the current one Idle controller contribution depending on the speed or subtract moment contributions until the resulting Idle controller contribution is zero.

The procedure shown is in an analogous manner in Used in connection with the control of electric motors.

Furthermore, in one embodiment for determination the speed-dependent change of the idle controller signal not the engine speed, but one, e.g. to the idle target speed, standardized size used. This is beneficial when using an operating state dependent (standardized) Speed threshold for the idle control, whose Activate when this speed threshold is undershot the (normalized) engine speed occurs.

Claims (12)

Method for operating a drive motor, a resultant predefined variable for controlling the drive motor being determined as a function of the driver's request and other predefined variables, a correction variable depending on the engine speed being also formed by an idle speed controller, characterized in that the correction variable of the idle speed controller is based on the resulting predefined variable is switched on, with the transition from idle mode to non-idle mode or vice versa, the correction variable of the idle controller is changed depending on the engine speed or time. A method according to claim 1, characterized in that default sizes and correction size are torque sizes that represent wheel torques, engine output torques or indicated engine torques. Method according to one of the preceding claims, characterized in that a time-dependent deactivation or activation of the correction variable of the idle controller takes place when the accelerator pedal is actuated. Method according to one of the preceding claims, characterized in that when the accelerator pedal is actuated, a factor is changed as a function of time, with which the correction variable of the idle controller is weighted. A method according to claim 4, characterized in that the factor is changed as a function of time from one to zero or vice versa. Method according to one of the preceding claims, characterized in that a factor is formed depending on the engine speed, with which the correction variable of the idle controller is weighted, the factor decreasing as the engine speed increases. A method according to claim 6, characterized in that the factor changes from one to zero with increasing engine speed. Method according to one of the preceding claims, characterized in that loss moments are formed which represent the torque requirement of secondary consumers and / or the torque to be applied by the drive motor as a result of internal friction, this loss torque value being applied to the resulting default value and the applied loss torque quantity being in the opposite direction to the correction quantity of the Idle controller is weighted. Method according to one of the preceding claims, characterized in that the correction variable of the idle controller is limited to a maximum value and / or a minimum value, the maximum value and / or the minimum value being changed as a function of the engine speed or as a function of time during the transition from idle mode to non-idle mode or vice versa. Device for operating a drive motor, with a control unit which, from a driver's desired size and default sizes of further control systems, forms a resulting default size for controlling the drive engine, which includes an idling controller which forms a correction variable, characterized in that the electronic control unit has means which determine the correction variable of the idle controller apply the resulting default size, the correction variable of the idle controller being changed as a function of engine speed or time depending on the transition from idle mode to non-idle mode or vice versa. Computer program with program code means to all Steps of any of claims 1 to 8 perform when the program is run on a computer becomes. Computer program product with program code means which are stored on a computer-readable data medium, the method according to any of claims 1 to 8 if the program product on a Computer is running.

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