DE102006044773A1 - Accelerator pedal insertion point for hybrid vehicles - Google Patents

Abstract

The invention relates to a method for operating a at least one internal combustion engine and at least one electric machine having drive device of a hybrid vehicle, in particular by a driver-side actuation of a minimum position and maximum position freely adjustable operating element of the drive device, a drive torque is predetermined by this, wherein in the overrun mode of the hybrid vehicle, the minimum position of the operating element corresponds to at least one loss torque composed essentially of engine and / or auxiliary machine losses and forms at least one accelerator pedal attachment point. It is envisaged that in the overrun mode, a reproducible vehicle drive torque of the hybrid vehicle is present at the minimum position of the operating element by influencing the accelerator pedal insertion point by means of an additional electric machine torque of the electric machine.

Description

The The invention relates to a method for operating an at least an internal combustion engine and at least one electric machine having drive device of a hybrid vehicle, in particular a hybrid motor vehicle, in which by driver side actuation of a between minimum position and maximum position freely adjustable control element the drive device, a drive torque of this predetermined is, wherein in the overrun mode of the hybrid vehicle, the minimum position of the operating element at least one essentially of internal combustion engine and / or accessory losses composed loss torque corresponds and provides at least one accelerator pedal insertion point.

State of technology

drive devices of the type mentioned are known. It is in the control unit of the vehicle the driver's request on the control element, for example on the accelerator pedal detected. From the position of the control is by means of appropriate Algorithms a driver's desired torque determined. Subsequently, will the drive unit is controlled so that the vehicle behavior the Desire of the driver corresponds. In conventional vehicles with one Internal combustion engine can drive torque depending on the position of the control element (Accelerator pedal angle) present as a characteristic. Additional dependencies, for example from Vehicle speed or speed of the internal combustion engine, can in Maps are entered. These characteristics or fields include only positive moments, that is, that losses, which are essentially due to engine losses Compose friction and charge changes as well as ancillary losses not in the curves or fields, but only by addition be taken into account. Is the vehicle in overrun mode, ie the operating element is in minimum position and the speed of the vehicle is greater than zero, Thus, the loss torque of the engine and / or forms Anlagatsverluste an accelerator pedal insertion point. The driver can ie by adjusting the control element between the minimum position, the accelerator pedal insertion point or the torque loss corresponds to the engine and / or ancillaries losses, and a maximum position, the maximum torque of the internal combustion engine corresponds, select. Advantage of direct dependence The torque of the torque loss is the avoidance of a lower Leerwegs, that is the Drive the vehicle also responds to small settings of the Operating element by a corresponding increase in the engine torque. Because the loss moment but from a big one Number of factors, such as For example, the speed of the internal combustion engine and its temperature, is dependent It can, for example, in a diesel engine with high temperature-dependent friction come in cold condition to unexpectedly large loss moments, the for the comfort of the driver is not acceptable.

It is also known ( DE 05 102 33 576 ) that in order to increase the driving comfort depending on a current driving resistance, a minimum value and / or a maximum value for the acceleration of the motor vehicle is determined and that the minimum value and / or the maximum value are each assigned to a limit of the control range of the control element. In this way it can be prevented that, for example when downhill an idle travel (way that the control element must be moved out of the minimum position until the engine a drive torque can be specified) and when driving uphill a dead path (way the control element to the maximum position can go without the drive torque changes) arises. Losses of the internal combustion engine and / or ancillaries are not taken into account here.

epiphany the invention

The Invention has the advantage that in a hybrid vehicle at minimum position the control element in overrun a reproducible drive torque, independently from the losses of the internal combustion engine and / or ancillary units, is present. In overrun is for the accelerator pedal insertion point of the hybrid vehicle by means of an additional Electric machine torque of the electrical machine influenced. bring the driver the control element in its minimum position, so goes the drive device in overrun, that is in the internal combustion engine find no ignitions or injections in the cylinder more, and the engine is dragged along. Of the Driver feels doing a delay, since that caused by the internal combustion engine and its ancillaries Loss moment has a negative effect on the drive torque, where For example, in a cold start of the internal combustion engine, the friction losses and the resulting loss moment are much higher as with a warmed-up engine. Depending on the operating state can So the strength the delay vary, which can be perceived by the driver as unpleasant. By operating the drive device of a hybrid vehicle according to the invention The electric machine can be controlled so that the sensed deceleration for the driver is always reproducible.

In a further advantageous embodiment, the respective accelerator pedal insertion point is above or below the loss moment. By controlling the electric machine, therefore, the deceleration torque felt by the driver may be greater or smaller than the actual torque losses of the internal combustion engine and / or the ancillaries. This allows an optimal adjustment for the deceleration behavior of the hybrid vehicle.

It is advantageous if the respective accelerator pedal insertion point within an area that is connected to the electric machine and possibly the their associated electrical components at the time is feasible. The electrical components are for example an electrical storage, which is used in the motorized operation of the electric Unloading the machine and loading it during regenerative operation. Because the capacity the electrical storage is limited during charging and discharging, it makes sense to set the accelerator pedal insertion point within a range to lay out the capacity the memory is not overwhelmed, otherwise a lower free travel can not be avoided, so small settings of the control element have no effect on the drive torque, or the memory is overloaded becomes.

Farther it is advantageous if at least one accelerator pedal insertion point is present, in which the electrical machine is operated as a generator. Thereby the recuperation potential of the electric machine can be used become.

To a development of the invention, it is provided that the accelerator pedal insertion point is given, so that always the same (negative) drive torque in overrun mode.

It is advantageous if the accelerator pedal insertion point in dependence a speed in the drive train of the drive device, such as Example of the speed of the internal combustion engine or the electric Machine, is specified. So, for example, in a hybrid vehicle with manual transmission the driver in different gears different deceleration behavior expect. About that In addition, a speed-dependent Limitation of Rekuperationspotentials be considered.

Farther it is advantageous if the accelerator pedal insertion point in dependence the vehicle speed of the hybrid vehicle is specified. Thereby can the delay the hybrid vehicle of the speed adjusted and an optimal deceleration behavior will be realized. So can a speed and thus gear independent delay behavior be achieved, which is particularly true in automated transmissions is beneficial.

To a development of the invention is provided that the reproducible Vehicle drive torque always the same size, regardless of State changes, such as a gear change of a transmission of the hybrid vehicle. By a quick change the clutch torque depending from the translation of the Getriebes a constant wheel torque can be ensured. The fast change the clutch torque can be accomplished by the electric machine become.

To a development of the invention is provided that the accelerator pedal insertion point dependent on is specified by a Rekuperationsmoment. When operating the Drive device of the hybrid vehicle in an operating point, in which a constant accelerator pedal insertion point is required, can It happens that by, for example, shutting off ancillaries consumers, ie by reducing losses, the Rekuperationsmoment is greatly increased, so that the deceleration torque for the Driver remains reproducible. This may result a very heavy load on the electric machine respectively the electrical components associated with it, such as an electrical store. If the accelerator pedal insertion point in dependence given by the recuperation, so is by a suitable Specification of Rekuperationsmoments example, an overload of the electrical storage avoided. Whereby the recuperation moment Here, therefore, represents a virtual moment, which is used to calculate a Accelerator attachment point serves, the corresponding (generator) Moment of the electric machine causes.

advantageously, the recuperation moment becomes dependent on a drag torque the internal combustion engine specified, the drag torque loss torque the internal combustion engine in overrun mode corresponds. The drag torque is particularly dependent from the speed and the temperature of the internal combustion engine.

advantageously, is the Rekuperationsmoment depending on at least one An accessory torque of the drive device specified. By the consideration the drag torque of the internal combustion engine and the at least one Ancillary torque becomes a largely reproducible deceleration torque ensures the hybrid vehicle.

Advantageously, the recuperation torque is predefined as a function of at least one electrical system of the hybrid vehicle. It is particularly advantageous if the recuperation torque is predetermined such that the electrical Ma At least enough energy is produced to ensure that the electrical system is still adequately supplied. The power supply of the electrical system also includes the power supply of the connected units. It is also advantageous to specify such a recuperation torque that the electrical system or the associated units are not overloaded.

To a development of the invention, the recuperation in the limited idle speed range of the internal combustion engine, so that at least the electrical system is adequately supplied.

Around a conflict with an idle controller, the speed of the internal combustion engine and / or keeps the electric machine at idling constant, to avoid the recuperation torque in idle speed range is advantageously equal set to zero.

advantageously, the recuperation torque is specified as a characteristic field and / or characteristic curve. The map and / or the characteristic can in a memory a control unit of the hybrid vehicle are stored. advantageously, becomes the map and / or the characteristic curve as a function of a speed the powertrain, such as the speed of the internal combustion engine or from the electric machine, given.

To In a further development of the invention, the recuperation moment is achieved by means of a calculation rule during operation of the hybrid vehicle determined, for example, the power requirements of the electrical system in a moment, considering of the idling speed range, is converted and where a high drag torque of the internal combustion engine, for example at a Cold start, and loss moments of the ancillaries by reduction considered the recuperation become. Particularly advantageous is a combination of an example applied Rekuperationsmoment in the form of the characteristic curve or of the map and a calculation rule for limiting the Rekuperationsmoments.

Consequently can one by switching on and off of consumers or Ancillaries strongly fluctuating Rekuperationsleistung the electrical Machine avoided or allowed.

Short description of characters

The The invention will be explained in more detail below with reference to the drawings. It demonstrate:

1 a method for controlling the hybrid drive, wherein the accelerator pedal insertion point has the states: fixed, depending on the rotational speed of the internal combustion engine or the speed of the hybrid vehicle,

2 the method according to 1 in which the accelerator pedal insertion point is limited to adjustable torques,

3 a table that illustrates the problem with a fixed touchdown point,

4 a method for controlling the hybrid drive under specification of a Rekuperationsmoments and

5 a method for determining the Rekuperationsmoments.

Embodiment (s) of the invention

1 shows an operating schematic of the drive device of a hybrid vehicle, the internal combustion engine 11 and an electric machine 13 has, whose output shafts are operatively connected to each other. In particular, the operating scheme represents the control of the drive machines. It shows 1 an element 1 and an element 2 , each one a directed connection 3 . 4 to a connection point 5 have a connection 6 to an element 7 has, from which a connection 8th to the element 9 goes, from which a connection 10 to the internal combustion engine 11 , and another connection 12 to the electric machine 13 leads.

element 1 represents a map in which a moment M, which may be present as a wheel, transmission output or clutch torque, via an accelerator pedal position F as a function of a further variable, such as the speed n of the internal combustion engine or the vehicle speed v, is plotted three curves are exemplified, one of which has its origin in the axbox and initially rises steeply before it becomes flatter and almost parallel to the abscissa. Two further curves are drawn, which also have their origin at the intersection of ordinate and abscissa, but have different starting points on the third axis, with the increase of the third value (engine speed n, vehicle speed v), the initial slope is lower and the curves in the further Course lie below the first curve. The element 1 thus represents the stored in the control unit of the drive device map, which is used when the driver specifies a desired torque by the position of the control element or the accelerator pedal.

element 2 represents an exemplary characteristic of the accelerator pedal insertion point A. On the ordinate the accelerator pedal insertion point A and on the abscissa the speed v of the hybrid vehicle is plotted. Alternatively, the characteristic of the accelerator pedal insertion point A can also be plotted on the speed. The characteristic starts below the abscissa and runs in a slight slope which decreases with increasing velocity v, whereby it does not intersect the abscissa. This characterizes the element 2 the accelerator pedal insertion point A, which is given for example as shown in the diagram, depending on the speed of the hybrid vehicle. The curve of the touchdown point can be designed so that the deceleration behavior of the hybrid vehicle at low speeds fails more than at high speeds.

Thereby It can be optimally adapted to the hybrid vehicle and / or the driver become. Alternatively, it could the accelerator pedal insertion point, for example, depending on the speed of the internal combustion engine or be fixed.

The element 7 characterizes this from the compound 6 of the element 1 with the element 2 resulting summed desired torque, which can be specified by the driver via the control element. For this purpose, the driver's desired torque FWM is plotted in the diagram as a curve on the accelerator pedal position F, for example. The curve begins on the ordinate below the abscissa, has a high slope at first, and approaches asymptotically to a value above the abscissa in the further course. The origin on the ordinate point of the curve is referred to here as the accelerator pedal insertion point A. The element 7 Thus, as already stated, represents the driver's desired torque as a function of the accelerator pedal position, wherein the driver's desired torque FWM is negative when the accelerator pedal is not pressed, since it is composed of the losses of the internal combustion engine and / or the ancillary components and a moment of the electric machine ,

The element 9 represents a control, based on the position of the control element and the above-mentioned characteristics of the internal combustion engine 11 and the electric machine 13 controls.

If the hybrid vehicle is in motion and the driver brings the control element into its minimum position or does not actuate the accelerator pedal, then it gives the drive device, as in element 7 shown, a negative desired torque (accelerator pedal insertion point A) before. A coming from the engine torque is negative if no injections and / or ignitions take place in the engine and the internal combustion engine is dragged, with losses (especially friction and Ladungswechselverluste the engine and losses of ancillary equipment), resulting in a negative moment impact. Does the resulting torque or loss torque of the internal combustion engine and / or ancillary units does not correspond to the value of in element 2 represented characteristic, so causes the control 9 that the electric machine 13 equalizes the difference between the loss moment and the accelerator pedal insertion point A. In this case, the electric machine 13 motor, when the loss torque is higher in magnitude than the accelerator pedal insertion point, or as a generator, when the accelerator pedal insertion point has a higher delay than can be achieved by the loss torque operated.

2 shows the same process scheme as in 1 with the difference that in the connection 4 between the element 2 and the connection point 5 another element 14 is interposed. The exemplary characteristic has its origin on the ordinate, but otherwise has the same course. The element 14 limits the accelerator pedal point on adjustable torques that can be realized with the electric machine and its associated electrical components and the internal combustion engine with the ancillaries. This can prevent that a so-called free travel occurs in which small settings of the control element or small accelerator pedal angle (positions F) have no effect on the drive torque. The electrical storage of the electric machine can not be overloaded and also not be discharged so that the electrical machine can no longer set the desired moment.

The 3 represents in a table the problem that can arise when an accessory is switched on or off. These are exemplary loss moments of the internal combustion engine together with the ancillaries 31 , for a fixed accelerator pedal attachment point 32 and for a required recuperation moment 33 Dependent on whether ancillaries in a first case 34 switched on or in a second case 35 are switched off, with the fixed accelerator pedal insertion point 32 for the two cases 34 and 35 is equal to. It can be seen that, to a fixed accelerator pedal insertion point 32 to get the recuperation moment 33 must be greatly increased when the ancillaries 31 are switched off and provide a lower loss moment. The greatly increased recuperation moment 33 This leads to the fact that, for example, a belonging to the electrical machine electrical energy storage is overloaded.

Around To prevent this, the accelerator pedal insertion point A is dependent predetermined by a (virtual) Rekuperationsmoment.

The 4 shows the Wirkschema for the drive train of a hybrid vehicle from the 1 , where the scheme of action instead of the element 2 an element 36 , which represents the torque losses of the internal combustion engine and the ancillaries, and an element 37 , which represents the recuperation torque, which an applied map or a characteristic 38 is removed and / or calculated, wherein the recuperation depending on aggregate limits 39 is limited. The element 36 is doing a connection 40 with the adding point 5 connected, from which a connection 41 to another adding point 42 leads, from which a connection 43 to the element 7 leads. From the element 37 leads a connection 44 also to the connection point 42 , Through the add-on points 5 and 42 the accelerator pedal point is calculated so that the recuperation moment 37 is always guaranteed. The element 7 represents the summed result. The recuperation moment 37 is chosen so that, for example, one to the electric machine 13 belonging electrical energy storage is not overloaded, and / or that a vehicle electrical system of the hybrid vehicle is just supplied with sufficient power. If the recuperation torque is determined in such a way that the resulting accelerator pedal insertion point is within the control range of the units, a lower dead path in the accelerator pedal is avoided. The map or the characteristic curve 38 are preferably in dependence of the speed of the internal combustion engine 11 predetermined, wherein in Leerlaufnahen speed range the Rekuperationsmoment 37 advantageously limited, so that at least the electrical system is supplied with sufficient energy, or is set equal to zero, so that no conflict with an idle controller of the internal combustion engine and / or the electric machine 11 arises. A calculation rule for calculating the recuperation torque 37 is designed so that also different parameters, such as aggregate limits 39 , be taken into account.

Advantageously, the Rekuperationsmoment by a combination of the map or the characteristic 38 and the calculation rule determined. The 5 shows an exemplary, step-by-step approach. In a first step 50 First, a recuperation torque based on the map or the characteristic curve 38 given, this particular depending on the speed of the internal combustion engine 11 is. In a second step 51 is optionally by the calculation rule, the drag torque of the internal combustion engine 11 considered by default 52 an upper and lower limit for the recuperation moment. This is especially important for highly temperature-dependent drag torques. For example, after a cold start of the engine 11 If the internal combustion engine has not yet reached its operating temperature, the recuperation torque is reduced, so that no excessively high deceleration torque acts on the hybrid vehicle. In a third step 53 is then by the calculation rule optionally the torque requirement of the ancillaries by a default 54 a limit for the Rekuperationsmoment considered. In a fourth step 55 is then by the calculation rule, also optional, the recuperation depending on the electrical system and aggregate limits by a default 56 limited. For example, the Rekuperationsmoment is limited so that the resulting accelerator pedal insertion point A allows a just sufficient supply to the electrical system. The recuperation torque determined in this way is subsequently transmitted via the connection 44 , as in 4 shown, included in the accelerator pedal insertion point A. Thus, temperature-dependent fluctuations in the drag torque of the internal combustion engine 11 and a switching on and / or off ancillary units are taken into account so that a highly fluctuating recuperation of the electric machine 13 avoided or allowed.

Claims (18)

A method for operating a at least one internal combustion engine and at least one electric machine having drive device of a hybrid vehicle, in particular a hybrid motor vehicle in which by driver side actuation of a freely adjustable minimum position and maximum position control element of the drive device, a drive torque is predetermined by this, wherein in overrun operation of the hybrid vehicle the minimum position of the operating element corresponds to at least one loss moment composed essentially of engine and / or ancillaries losses and forms at least one accelerator pedal insertion point, characterized in that in overrun a reproducible vehicle drive torque of the hybrid vehicle at minimum position of the operating element by influencing the accelerator pedal insertion point by means of an additional electric machine torque electrical machine is present. Method according to claim 1, characterized in that that the respective accelerator pedal insertion point above or below the loss moment lies. Method according to one of the preceding claims, characterized in that the respective accelerator pedal insertion point within a range is, which is realizable with the electric machine and possibly its associated electrical components in each time. Method according to one of the preceding claims, characterized characterized in that at least one Fahrpfafaufsetzpunkt exists, in which the electrical machine is operated as a generator. Method according to one of the preceding claims, characterized in that the accelerator pedal insertion point is predetermined, in particular fix is given. Method according to one of the preceding claims, characterized characterized in that the accelerator pedal insertion point in dependence a speed in the drive train of the drive device is specified. Method according to one of the preceding claims, characterized characterized in that the accelerator pedal insertion point in dependence the vehicle speed of the hybrid vehicle is specified. Method according to one of the preceding claims, characterized characterized in that the reproducible vehicle drive torque always the same size, independently of state changes, such as a gear change of a transmission of the hybrid vehicle. Method for operating a at least one internal combustion engine and at least one electric machine having a drive device of a Hybrid vehicle, in particular a hybrid motor vehicle, in which by driver-side operation one between minimum position and maximum position freely adjustable Operating element of the drive device, a drive torque of this can be predetermined, wherein in the overrun mode of the hybrid vehicle, the minimum position of the operating element at least one essentially of internal combustion engine and / or accessory losses composed loss torque corresponds and forms at least one accelerator pedal insertion point, in particular according to one or more of the preceding claims, characterized characterized in that in overrun a particular reproducible vehicle drive torque of the hybrid vehicle at minimum position of the operating element the influence of the accelerator pedal insertion point by means of an additional Elektromaschinenmoments the electrical machine is present, and that the accelerator pedal insertion point in dependence on a Rekuperationsmoment is given. Method according to one of the preceding claims, characterized characterized in that the Rekuperationsmoment in dependence a drag torque of the internal combustion engine is specified. Method according to one of the preceding claims, characterized characterized in that the Rekuperationsmoment in dependence is specified by at least one accessory torque. Method according to one of the preceding claims, characterized characterized in that the Rekuperationsmoment in dependence is predetermined by at least one electrical system of the hybrid vehicle. Method according to one of the preceding claims, characterized characterized in that the Rekuperationsmoment in dependence is specified by at least one aggregate limit. Method according to one of the preceding claims, characterized in that the recuperation torque in the idling speed range the internal combustion engine and / or the electric machine limited becomes. Method according to one of the preceding claims, characterized in that the recuperation torque in the idling speed range the internal combustion engine and / or the electric machine same is set to zero. Method according to one of the preceding claims, characterized in that the recuperation torque as a map and / or Characteristic is specified. Method according to one of the preceding claims, characterized in that the characteristic curve and / or the characteristic field are dependent is specified by the speed in the drive train. Method according to one of the preceding claims, characterized characterized in that the Rekuperationsmoment means of a calculation rule is determined.