EP3289217A1

EP3289217A1 - Method for regulating a fuel delivery pump

Info

Publication number: EP3289217A1
Application number: EP16718661.8A
Authority: EP
Inventors: Gerald BEHRENDT
Original assignee: Continental Automotive GmbH
Current assignee: Continental Automotive GmbH
Priority date: 2015-04-27
Filing date: 2016-04-25
Publication date: 2018-03-07
Also published as: KR20170135958A; WO2016173981A1; DE102015207682A1; US20180073498A1; CN107532579A; DE102015207682B4; CN107532579B

Abstract

The invention relates to a method for controlling a fuel delivery system, comprising a fuel delivery pump and an electric motor, wherein the fuel delivery pump can be driven by the electric motor and the electric motor can be controlled by a control current. According to the invention, the actual volume (27) conveyed by the fuel delivery pump is determined at a predeterminable point in time and at an actual pressure (25) prevailing at this point in time, wherein a target rotational speed (29) for the electric motor driving the fuel delivery pump is derived from the determined actual volume (27) and a target pressure (26).

Description

description

Method for controlling a fuel pump Technical field

The invention relates to a method for controlling a KraftStofffördersystems, with a KraftStoffförderpumpe and with an electric motor, wherein the KraftStoffförderpumpe is driven by the electric motor and the electric motor is driven by a drive current.

PRIOR ART Internal combustion engine powered vehicles have a

KraftFörffördersystem, which is designed to ^¬ fuel from the tank to promote the internal combustion engine. For this purpose, the fuel delivery system has regularly to a force ^¬ fuel supply pump which has at least one pumping station and an electric motor. By adjusting the current on the electric motor whose speed can be influenced and so ^¬ with the flow rate of KraftStofffördersystems.

In the prior art devices are known, which are regulated on the basis of the pressure prevailing in the KraftFitffördersystem. In this case, based on a known desired pressure and a known actual pressure via a simple controller, such as a PID controller, a target speed is determined, which is necessary to promote the desired flow through the KraftStoffförderpumpe. The electric motor is controlled via the PID controller such that the setpoint speed is set, which was determined as a function of the desired desired pressure. A disadvantage of these devices is that the control quality of a simple controller is not the same over the entire Arbeitsbe ^¬ rich the controller. This leads in some range, especially in low speed ranges, excessive overshoot and partial resonances. Often to expect a significantly slower control speed or that the bed controller can adequately rea ^¬ lust on interference is Gleichzei ^¬ tig in particularly high speed areas.

Summary of the invention, object, solution, advantages Accordingly, it is the object of the present invention, a drive Ver ^¬ which enables improved in terms of control accuracy ^¬ speed and the control quality control of the fuel delivery system. The object concerning the method is achieved by a drive Ver ^¬ solved with the features of claim. 1

An embodiment of the invention relates to a method for controlling a Kraftofofffördersystems, with a fuel pump and an electric motor, wherein the ^¬ fuel pump is driven by the electric motor and the electric motor can be driven by a drive current, wherein at a predetermined time by the KraftStoffför ^¬ funded pumped actual volume is determined at a prevailing at this time actual pressure and from the specific actual volume and a desired pressure, a target speed for the fuel pump driving the electric motor abgelei ^¬ tet. This is particularly advantageous because not only on the basis of an actual pressure and a target pressure, a target speed is passed from ^¬ , but the funded volume is used as an intermediate ^¬ size. The project, funded actual volume before ^¬ preferably agrees Working on the basis of the actual pressure and the actual speed, making a statement with high accuracy can be achieved on the actual volume. The actual volume is then preferably used in a further determination, in which, with the aid of the desired pressure, which can also be predetermined with a high quality, a target speed can be determined, which is given to the electric motor as a target.

Overall, the determination of the target speed is very ge ^¬ accurate and occupied only with low interference.

The electric motor is preferably controlled by varying the Stro ^¬ mes, with which it is driven. Due to the known characteristics of the electric motor and the remaining KraftStofffördersystems the necessary current to achieve a certain target speed under given boundary ^¬ conditions can be specified very accurately. In particular, the prevailing in the fuel feed system pressure is a re ^¬ levante constraint here.

It is particularly advantageous if the predetermined point in time to the conveyed by the fuel pump the actual volume of a known characteristic field with knowledge of the value existing prior ^¬ actual pressure and the actual speed accompanying it will ^¬ is averages.

For each specific fuel delivery system can identify a map that a connection between the ge ^¬ promoted volume, the speed and the pressure prevailing in the fuel delivery system ^¬ print forms. A typical map shows on the X-axis, the speed of the fuel pump, on the Y-axis, the funded volume and curves ver ^¬ running in the quadrants ^spanned by the axes as isobars. With two known values each, the third missing value can be determined.

Particularly preferable it is, if each be ^¬ known values were determined at the same time, since all values can change with the passage of time, where significant changes occur in very short periods of time can. Therefore, it is advantageous if the value determination happens at a given time. Of course, the determination can be done continuously on a continuous basis. In this case, however, it is advantageous if the actual values determined in each case from the fuel-substance delivery system are always determined at an identical point in time.

It is advantageous, even if the actual volume is determined from a ^¬ be known characteristic field with knowledge of the actual pressure and the actual drive current.

In an alternative characteristic diagram, the drive current may also be plotted instead of the rotational speed. The map retains its overriding statement and will only look different. Also with the strength of the drive current and the volume delivered per ^¬ Weil can closed on the pressure who ^¬ the or vice versa. It is thus given an alternative determination of the promoted actual volume.

A preferred embodiment is characterized ^¬ net, that the target speed for the electric motor by means of the determined actual volume and the predetermined target pressure from a map is determined.

This is particularly advantageous as the value for the target speed can be be ^¬ true also from a map particularly easy. A map is advantageously used, which curves bears on the X-axis, the rotational speed, the ge ^¬ promoted volume on the Y axis and in the plane spanned by the axes of quadrants in the form of isobars, wherein the iso ^¬ cash the prevailing respectively in the fuel delivery system Pressure correspond. As known variables of the target pressure and the specific size as an intermediate conveyed actual volume are used to determine a target speed. This is particularly easy and therefore can quickly bewerkstel ^¬ ligt. The maps needed to be created on the basis of compute ^¬ th values and / or on the basis of empirically determined values. Since between the pressure and the delivery quantity ^¬ there is a direct physical connection, a good correlation can be achieved.

It is also preferable if the actual volume and the target speed are determined from the same map.

Both being as Zvi's size ^¬ used to determine the target rotational speed, determined as the target rotational speed on the basis of the same characteristic diagram actual volume, is particularly preferred. This is advantageous because only a map in the vehicle electronics must be mapped. This saves Spei ^¬ cherkapazität and thus results in a more favorable design of the fuel delivery system. Moreover, Def ^¬ lerquellen whereby the quality of the total Rege ^¬ averaging method is improved are reduced.

In alternative embodiments, the map can also be in ta ^¬ bella imperious form or in the form of regulations Berechnungsvor ^¬. Also other factors can be considered in the map so that a further increase in the Ge ^¬ accuracy can be achieved.

Moreover, it is advantageous if the determined actual volume is processed in a correction module, wherein at ^¬ additionally the actual pressure and the target pressure in the Korrekturmo incorporated ^¬ dul and an adapted actual volume is determined, adapted from the Actual volume and the target pressure by means of a known map, a target speed for the electric motor is determined.

A correction module may be ausgebil ^¬ det as a separate component or be stored in one of the control devices used as Re ^¬ chenroutine. The correction module is preferably used to determine the value determined for the fuel supply system in the fuel supply system corrected actual volume to be corrected. Here, in particular ^¬ sondere interference are to be minimized or from the outside or from within the fuel delivery system entirely eliminated.

The determination of the desired speed can also take place in the correction ^¬ module. Alternatively, this can also be provided a separate module. The correction module should CARDINAL ^¬ Lich the influence of the change in volume to pressure entge ^¬ genwirken to eliminate this source of error. But other interference can be expected over the correction module through appropriate algorithms and computational methods from the target ^¬ worth it for the desired speed out.

Furthermore, it is advantageous when the correction module is used the pressure-dependent change of the conveyed Volu ^¬ mens for correction. This is advantageous because the druckabhän ^¬ dent volume change can not be affected and therefore this phenomenon will always occur.

It is also expedient if the correction module for correcting the actual volume which also receives input values, which reflect the pressure-dependent behavior of other elements of the motor ^¬ material conveying system. These include in particular an ejector and / or a venturi pump and / or a Dü ^¬ se.

Since the KraftStofffördersystem in addition to the main power Stoffför ^¬ pump also has secondary pumps, which are necessary for example for the filtering or the suction of the fuel, a pressure change also affects in particular these secondary pumps. Overall, therefore, a Berücksichti ^¬ supply this pressure-dependent behavior is advantageous to maintain the quality of the determined value as high as possible for the desired speed. Moreover, it is advantageous if the determined target speed for the electric motor in a PID controller is as a ^¬ given input variable and the electric motor is controlled by the PID controller.

A PID controller can advantageously achieve fast control with high control quality. The determined with a high accuracy target speed can therefore be easily and reliably achieved by the controller selects a suitable current for driving the electric motor depending on the respective target speed.

Furthermore, it is expedient if the actual pressure is determined by a pressure sensor or in that the actual pressure is determined by a calculation method and / or comparison method.

Depending on the structure of the fuel delivery system, the Determined ^¬ development of the pressure prevailing in the fuel supply system pressure may take place in some way with a dedicated pressure sensor or pressure sensor without using computational methods and / or comparison process. Forth

Advantageous developments of the present invention are described in the dependent claims and in the following Figurenbe ^¬ description.

Brief description of the drawings

In the following the invention will play on the basis of Ausführungsbei with reference to the drawings explained in detail. In the drawings show:

1 is a block diagram in which the process of he ^¬ inventive method is illustrated, 2 is a diagram showing a map for the geför derter volume over the speed, wherein in the ordinate system isobars are located,

Fig. 3 is a block diagram illustrating an alter native embodiment of the procedural inventive method, and

Fig. 4 is a block diagram to illustrate a wide ren alternative embodiment of the method.

Preferred embodiment of the invention

FIG. 1 shows a block diagram 1, which reflects the course of the method according to the invention. On the blocks 2, 3 and 4, input values are inputted into the drive Ver ^¬ processed in subsequent blocks 5 and 6. FIG. Finally, a generated output is output via block 7.

Block 2 provides as an input variable the current actual pressure at the time of data collection. The actual pressure may be so ^¬ well classically determined by a pressure sensor and by a calculation method or by Vergleichsver ^¬ drive are determined. Via the block 3, the current actual speed is input as a further input variable, which corresponds to the speed that applied to the electric motor or the pumping station at the time when the actual pressure was determined.

Via the signal lines 8 and 9, the input variables are supplied to the block 5. In block 5 is made of the actual pressure and the actual rotational speed with the aid of known characteristic fields, which map the respective fuel-transfer system, an actual Volu ^¬ men determined, which is supported by the fuel conveying system at a given actual speed and a given actual pressure. The actual volume is continued via the signal line 11 to the block 6.

In the block 6 is also on the signal line 10 originating from the block 4 input quantity of the target pressure, which describes the targeted target pressure. In block 6, a target speed is determined with the aid of the actual volume from block 5 and the desired pressure, which is finally output via the Signallei ^¬ device 12 via block 7 as output. The determination of the desired speed can also be done via a map with knowledge of the actual volume and the target pressure. Ideally, the same map can be used in block 6 even that has already ver ^¬ applies also in block fifth

The actual volume is generated in the process of Figure 1 as an intermediate ^¬ size, the actual volume on the basis of values it is ^¬ averages, which have a high accuracy. The Ver ^¬ application of the actual volume is particularly advantageous because directly the physical behavior of the pump is taken into account.

Also, by an additional volume adaptation, as shown in the embodiment of Figure 4, an adaptation to the control system used in each case and in particular to their physical properties.

Figure 2 shows a diagram 20 which represents a particular characteristic ^¬ field, as it was used for the determination of the actual volume in block 5 of Figure 1 and the determination of the target rotational speed in block 6 of FIG. 1 Diagram 20 is an example and represents one possible configuration of a fuel delivery system.

By the reference numeral 21, the X-axis is referred to wel ^¬ cher the revolutions of the electric motor are removed per minute. It may also be the speed of the pump of the KraftStoffförderpumpe. As a rule, these speeds are essentially identical, since the pumping station is usually borrowed without gear transmission is driven directly by the electric motor to ^¬.

Reference numeral 22 denotes the Y-axis, on which the delivered volume is removed in 1 / h. In the squares spanned by the axes 21, 22, a plurality of straight lines 23 are formed, forming isobars. Along each of the straight lines 23, the same pressure prevails in the fuel supply system. Along the arrow 24, the respective pressure of the isobars 23 increases.

Starting from an actual rotational speed, which is represented for example by the point 28, the operating point can be determined from the diagram 20 with known actual pressure 25, to which an actual volume corresponding to the point 27 is assigned. This actual volume 27 thus corresponds to the size which is generated in block 5 of FIG. 1 as an output variable and is transferred via signal line 11 into block 6. Starting 27 by reference to the setpoint pressure 26 of block 3 of Figure 1 can be reached in Figure 2 to an operating point which the associated target speed is supplied ^¬ allocates 29 of the actual volume. This method corresponds to block 6 of FIG. 2.

With the aid of a map, as shown in the diagram 20 of Figure 2, thus the actual volume and be ^¬ known set pressure, the target speeds for different operating conditions of a fuel pump can be determined.

Figure 3 shows a block diagram 30, wherein the input variables provided to dispose of the blocks 31, 32 and 33 who ^¬. From block 36, the output is output. In block 34, the determination of the actual volume takes place, which is processed in block 35 to a target speed. The ^¬ A gear sizes can be via the signal lines 37, 38 and 39 distributed on the blocks 34 and 35th The structure of the block diagram of 30 is similar in many parts of the block diagram 1 of the Fi ^¬ gur 1. Deviating from Figure 1 is the block 32 as a ^¬ output variable is not the actual speed fed, but the actual current intensity with which energizes the electric motor to the considered instant becomes.

In a known KraftStofffördersystem can from the

Amperage with which the electric motor is driven, are also closed to the speed of the electric motor. The current thus forms a counter to the speed from ^¬ exchangeable size. Both quantities can be used synonymously in the process according to the invention.

As shown in Figure 1, the actual volume is determined via nalleitung causes signal 40 to the block 35 out where a target rotational speed is determined with the aid of the target pressure, which is output as basic ^¬ position for driving the electric motor.

Figure 4 shows an alternative embodiment of a block diagram 50, which images the inventive method in an expanded form.

Via the blocks 51, 52 and 53, the input variables actual pressure, actual speed and target pressure are supplied. In block 54, the actual pressure and the actual speed, which is guided along the signal line 59 in the block 54, processed to an actual volume. The actual volume is then passed via the Sig ^¬ nalleitung 61 in the block 55, where it is under ^{Einbezie ¬} hung of the actual pressure, which is supplied via the signal line 58, and the target pressure, via the signal line 60 to ^¬ is processed to an adapted actual volume. About the adaptation in block 55 is to take place an error correction of the determined actual volume. In addition, the effects of other disturbances affecting the actual volume can also be eliminated in block 55. Insbeson ^¬ particular the property changes the volume of the pressure that can so be compensated. The adapted actual volume is then supplied via the signal line 62 into the block 56, where, with the aid of the setpoint pressure, a setpoint speed analogous to the exemplary embodiments of FIGS. 1 and 3 is determined. This setpoint speed is output via the signal line 63 to the block 57 as an output variable ^¬ .

The output variables, which are output via the blocks 7, 36 and 57, can be fed directly into a control unit, which causes the control of the electric motor. In particular ^¬ sondere the output variables can also be added in a classic PID controller, which transforms the target rotational speed in a per ^¬ weiligen and drive current to the electric motor supply.

There are also combinations of the embodiments of Figu ^¬ ren 1, 3 and 4 providable. In particular, as one of the A ^¬ gear sizes in Figure 4 also, the actual current can be used as it is for example used in FIG. 3

The embodiments of Figures 1 to 4 have insbeson ^¬ particular any limiting character and serve to Ver ^¬ deutlichung the inventive concept.

Claims

Method for controlling a KraftStofffördersystems, with a KraftStoffförderpumpe and with a Elektromo ^¬ tor, wherein the KraftStoffförderpumpe is driven by the electric ^¬ motor and the electric motor is driven by a Ansteuerstrom, dadurchge ^¬ indicates that at a predetermined time ^¬ point by the KraftStoffförderpumpe pumped actual volume (27) is determined at this time mr ^¬ nant actual pressure (25) and from the bE ^¬ voted actual volume (27) and a target pressure (26), a target rotational speed (29) for which the fuel pump is ^¬ driving electric motor is derived.

The method of claim 1, dadurchgekenn ^¬ characterized in that the at the predetermined point in time delivered by the fuel pump actual volume (27) (of a known characteristic field (20) having regard to the prevailing actual pressure (25) and the adjacent actual speed 28 ) is determined.

Method according to one of the preceding claims, characterized in that the actual volume is determined from a known map with knowledge of the actual pressure and the actual drive current.

Method according to one of the preceding claims, characterized in that the target rotational speed (29) for the electric motor by means of the he ^¬ mediated actual volume (27) and the predetermined target pressure (26) from a map (20) is determined.

Method according to one of the preceding claims, characterized in that the actual volume (27) and the setpoint speed (29) are determined from the same characteristic field (20). Method according to one of the preceding claims, characterized in that it ^¬ mittelte actual volume (27) in a correction module is verar ^¬ beitet, wherein in addition the actual pressure (25) and the target pressure (26) incorporated in the correction module and an adapted actual volume is determined, wherein from the adapted actual volume and the target pressure (26) by means of a known map (20) a target speed (29) for the electric motor is determined.

A method according to claim 6, characterized marked ^¬ characterized in that the correction module is used to correct the pressure-dependent change of the delivered volume.

Method according to one of the preceding claims 6 or 7, characterized in that the correction module for correcting the actual volume (27) also receives input variables which the pressure-dependent Ver ^¬ hold of other elements, in particular a suction ^¬ jet pump and / or a Venturi pump and / or a nozzle of the KraftFörder conveyor system.

Method according to one of the preceding claims, characterized in that it ^¬ mittelte target rotational speed (29) for the electric motor in egg ^¬ NEN PID controller is given as an input variable and the electric motor is controlled by the PID controller.

Method according to one of the preceding claims, characterized in that the actual pressure (25) is determined by a pressure sensor or in that the actual pressure (25) is determined by a calculation ^¬ method and / or comparison method.