FI124890B - Adjusting the Engine Fuel Supply - Google Patents

Description

ENGINE FUEL SUPPLY ADJUSTMENT

Engineering

The invention relates to the control of internal combustion engines. The invention relates in particular to the decentralized control of fuel supply to internal combustion engines.

Brief Description of the Invention

An object of the invention is to provide distributed motor control. The object is achieved as described in the independent claims.

List of figures

In the following, the invention will be described in more detail with reference to the accompanying drawings in which

Figure 1 shows an example of a fuel feed control system according to the invention;

Figure 2 shows another example of a fuel feed control system according to the invention;

Figure 3 shows a control unit for controlling the fuel supply in the example of Figure 1;

Figure 4 shows a third example of a fuel feed control system according to the invention;

Figure 5 shows a control unit for controlling the fuel feed in the example of Figure 4;

Fig. 6 is a flow diagram illustrating an embodiment of a control method for controlling the fuel feed in the example of Fig. 5;

Fig. 7 is a flow diagram illustrating another embodiment of a control method for controlling the fuel feed in the example of Fig. 5;

Figure 8 shows a third example of a control unit for adjusting the fuel supply;

Fig. 9 is a flow diagram showing a control method for adjusting the fuel feed in the example of Fig. 8;

Figures 10 to 12 show a fourth example of a control unit for adjusting the fuel supply;

Fig. 13 shows a control unit for controlling the fuel supply in the example of Figs. 10-12; and

Fig. 14 is a flow diagram showing a control method for adjusting the fuel feed in the example of Fig. 13.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows an example of an isochronous control of an internal combustion engine. The velocity unit 4 provides position information from which it is possible to determine the position of the engine pistons, which enables s y 1 inter-fuel adjustment and timing. In this example, the position information is obtained from the sensor 3 which detects the rotation position of the flywheel 1. The speed unit 4 modifies the data produced by the sensor 3 and produces the speed data 41 used to adjust the fuel supply to the engine cylinders.

The engine is controlled by three control units 10. Each control unit 10 has a control module 100 for controlling cylinder fuel injection valves (not shown).

The first control module, indicated by reference numeral 11, controls the fuel injection valve of the cylinder 1. The second control module, represented by reference numeral 12, controls the fuel injection valve of the cylinder 2. A third control module, represented by reference numeral 13, controls the fuel injection valve of the cylinder 3. It is clear that the number of cylinders may vary.

The speed measurement data 41 from the speed unit 4 is supplied to each control unit 10. In this case, the speed measurement data 41 is received in the speed data input 40 of the extreme left control unit 10 and simultaneously in the speed data input 40 of the other control units 10.

The control modules 100 are interconnected by a communication line 6 arranged between the control units 10. The communication line 6 is connected to the communication devices 40 of the control unit 10. A communication protocol, e.g. CAN (Controller Area Network), allows the devices to communicate with each other. Note that the communication protocol used to communicate between control modules may vary. The communication devices 60 serve as an interface between the control modules 100 and the communication line 6.

Figure 2 shows another example of a fuel feed control system. This embodiment differs from the example of Fig. 1 in that the speed unit 4 is integrated into one of the control units 10. The speed measurement data 41 produced by the speed unit 4 is applied to all control units 10. In this case, the speed measurement data 41 is received in the speed data feed 40

Figure 3 shows a control unit 10 for controlling the fuel supply in the example of Figure 1. The control module 100 of the control unit 10 is connected to the communication line 6 by communication means 60. The speed data receiving means 40 receive engine speed measurement data 41 produced by the speed unit 4. derivative).

The fuel supply data 11 controls a fuel control unit, such as a cylinder fuel injection valve.

The communication devices 60 are coupled to the communication bus 6 to establish a connection between the control modules 100. Due to the communication between the cylinder control modules, the load on each cylinder can be transmitted to all other regulators per cylinder specific fuel demand and thus it is possible to calculate the average cylinder load.

Each control module 100 is configured to export its reference data 62 to other control modules 100 by communication means 60. The control module 100 uses the highest value of the reference data 62 to determine fuel control data 11. Here, the communication means 60 is configured to select the highest value of the reference data 62. The selected data is transmitted to the local number generator 130. The reference data 62 used in the control module 100 is here selected by the communication devices 60. This selection may also be made by separate devices as shown in FIG. 13 at 620.

Each control module 100 estimates its cylinder-specific load data 61 based on the cylinder-specific fuel supply control data 11 with an estimator 150. This cylinder-specific load data 61 is transmitted to the other control modules via communication bus 6.

The control modules 100 are configured to create cylinder-specific load data 61 indexed so that the data can be identified as the data of a particular control module 100. The indexed data can be created / processed by the communication devices 60. This allows the control modules to determine the status of the control system.

The cylinder-specific load data 61 of the control modules 100 is calculated in a calculating unit, referred to herein as a calculator 110, which determines the average load data 112 of the control modules 100. The average of the load data 112 is used in the comparator 120 to determine the load deviation value 122 of the control module 100 by comparing the cylinder specific load data 61 of said control module 100 with the average of the load data 112 of the control modules. Here, the cylinder-specific load data 61 is received from the comparator, but the comparator may be coupled to the communication means 60 or the estimator 150 to obtain data.

Comparator 120 can receive said control module 100 from cylinder-specific load data 61 from estimator 150 or communication bus 6, wherein the cylinder-specific load data 61 is output indexed to correspond to said control module 100. The error in load distribution can be calculated by comparing average load to cylinder estimate. The load distribution error, i.e. the load offset, is subsequently used to replace the global speed reference, in this case the speed reference data 62.

The local velocity reference generator 130 generates cylinder-specific velocity reference data 132 by influencing the velocity reference data 62 by a specified load offset value 122.

The load offset value 122, i.e. the load distribution error, is used to replace the global velocity reference. For example, if the estimated local load is higher than the average cylinder load, the local velocity reference is reduced accordingly, and vice versa.

With steady state load distribution, the estimated local load is the same as the average cylinder load, regardless of the total engine load. This means that the load distribution error is zero and the local speed reference is the same as the global speed reference.

Figure 4 shows a third example of a fuel feed control system. This embodiment differs from the example of Figure 1 in that the control unit 10 includes a plurality of control modules, in this example three.

The first control module 100A controls the fuel injection valve shown on cylinder 1 with reference numeral 11. The second control module 100B controls the fuel injection valve shown on cylinder 2 with reference numeral 12. The third control module 100C controls the fuel injection valve shown in the cylinder 3 with reference numeral 13.

The speed measurement data 41 from the speed unit 4 is applied to each control unit 10. Here, the speed measurement data 41 is received by the speed data receiving unit 40 of the control units, here the extreme left control unit 10, and forwarded to the next data unit 10.

The control modules are connected by a communication line 6 arranged between the control units 10. The data of the communication line 6 is received by the communication devices 60 of the control unit 10.

The communication devices 60 serve as an interface between the control modules 100 and the communication line 6.

Figure 5 shows a control unit for controlling the fuel supply in the example of Figure 4. This embodiment differs from that shown in Fig. 3 in that the control unit 10 includes a plurality of control modules, in this example three control modules 100A, 100B, 100C.

The control modules 100A, 100B, 100C of the control unit 10 are connected to the communication line 6 by the communication devices 60. The communication devices 60 serve as an interface between the control modules 100A to 100C and the communication line 6.

The speed data receiving means 40 receives the motor speed measurement data 41 provided by the speed unit 4. The speed measurement data 41 is provided to each controller 140 of the control modules 100A, 100B, 100C. Depending on the system configuration, this speed measurement data 41 may be received or retrieved by the control modules 100A, 100B. Controller 140 provides specific fuel feed control data 11 based on said cylinder-specific speed reference data 132 and engine speed measurement data 41.

Fig. 6 is a flow diagram illustrating one embodiment of a control method for controlling the fuel feed in the example of Fig. 5.

The motor speed measurement data 41 from the speed data receiving means 40 is received by the controller 140. The speed reference data 62 from the communication devices 60 is received by the local speed reference generator 130.

Estimator 150 estimates cylinder-specific load data 61 based on cylinder-specific fuel feed control data 11.

The communication devices 60 supply this cylinder-specific load data 61 to the calculators 110 of the control modules 100A-100C via the communication line 6.

Calculator 100 calculates the average of the load data 112 of the control modules 100A to 100C from the cylinder-specific load data 61. The average of the load data 112 is used by the comparator 120 to determine the

The local speed reference generator 130 produces cylinder-specific speed reference data 132 by changing the speed reference data 62 by a specified load distribution offset value 122.

Controls 140 for each control module control fuel delivery based on cylinder-specific speed reference data 132 and engine speed measurement data 41.

Fig. 7 is a flow diagram showing another embodiment of a control method for controlling the fuel feed in the example of Fig. 5. This embodiment is suitable for use, e.g., in fixed propeller control. This embodiment differs from the method of Figure 6 in that the cylinder-specific speed reference data 132 (100A) is provided to the local speed reference generator 130 of the control modules 100A-100N.

The speed reference data 62 used to produce the cylinder specific speed reference data 132 is selected from the control module specific cylindrical speed reference data 132.

Cylinder-specific speed reference data 132 may also be included in the data section to identify the control mode of that cylinder. This allows manual / analog control of one cylinder so that other control modules can follow that selection. Other control modules, for example, start to use cylinder-specific speed reference data, which control mode is converted to analog. By providing the cylinder control mode to the control modules, the system can be operated in two isochronous modes, i.e., fixed or analog isochronous modes. The solid isochronous mode can use a predetermined nominal speed. The analog isochronous mode can be controlled by a separate control signal provided by the user or by an external system, for example a 4-20 mA signal. These modes can be prioritized so that the fixed mode control priority is higher. The method and the control unit can use the highest value, also taking into account this prioritization so that the fixed mode value is selected even if the analog mode values are higher.

Figure 8 shows a third example of a control unit for adjusting the fuel supply. The control modules 100A-100C differ from Figure 3 in that the cylinder specific fuel supply control data 11 is provided to the local rate reference generator 130 via filtering means 160.

In the isochronous mode, the local speed reference generator 130 produces cylinder-specific speed reference data 132 by influencing the speed reference data 62 with a load control value 123 or a load offset value 122.

In the droop mode, the local speed reference generator 130 produces cylinder-specific speed reference data 132 by influencing the speed reference data 62 at a specified load control value 123.

The load control value 123 is obtained from the fuel supply control data 11 by filtering the fuel supply control value by filtering means 160. The filtering means 160 may serve as a low pass filter suitable for reducing the effect of the variation.

When load distribution in Droop mode is used based on the current average cylinder load, the result is that the local speed reference tends to decrease as engine load is increased if no corrections are made, i.e., no increase / decrease in pulses from the user or external system. This embodiment provides an option to control the motor independently in the event of a malfunction in the communication between the control units 10.

Identification of inter-unit communication may be accomplished in communication devices 60 or local rate reference generator 130. Local rate reference generator 130 may select input 122 or 123 by priority selection. The local speed reference generator 130, for example, selects the use of the load control value 123 only if no other active inputs are available. By defining the communication mode, that is, between the control units, the system can be operated in two modes, i s o k r o n i s e s s mode or droop mode. The system operating in isochronous mode maintains the motor at constant speed regardless of the motor load. The system in Droop mode adjusts engine speed as a function of engine load. Note that the functions required in different modes can also be activated only when needed. This has the advantage that unnecessary calculations are not performed.

Figure 9 is a flow diagram illustrating a control method for adjusting fuel delivery in the example of Figure 8. This is a selective method of adjusting the fuel feed to an internal combustion engine, in which the engine speed measurement data is received by two or more control units containing control modules.

The communication state between the control units 10 is determined by the communication devices 60 and the YES path is implemented in the first mode of communication between the control units.

The method employs an estimated cylinder-specific frame rate based on the fuel supply control data 11 based on the data. Cylinder-specific load data is exported to the control modules. The average of the load data of the control modules from the cylinder-specific load data and the load deviation value 122 of that control module is calculated by comparing the cylinder-specific load data of that control module with the average of the load data of the control modules.

Cylinder specific speed reference data 132 is produced by influencing the speed reference data by a specified load distribution offset value 122. The fuel supply is controlled based on the cylinder specific speed reference data 132. In the second mode of communication between the control units, in which the communication is not determined to be valid, the method implements an EI path. The load adjustment value 123 of said control module from the cylinder-specific fuel supply control data 11 is determined.

Cylinder specific speed reference data 132 is produced by subtracting the load control value 123 from the speed reference data and controlling the fuel feed based on the cylinder specific speed reference data.

Figures 10 to 12 show a fourth example of a control unit for adjusting the fuel supply. This embodiment differs from the one previously described in that the control units 10 are connected to the main unit 5. The main unit 5 is connected to the communication line 6 by the communication devices 60.

The speed data receiving means 40 receives the engine speed measurement data 41 provided by the speed unit 4. The master controller 5 generates data for specific fuel supply control data based on the specific speed reference data and the engine speed measurement data 41. There is no need for isochronous mode control. This has the effect that the motor can be controlled in three different modes. The system of Figure 8 can be controlled in a known manner by the main unit 5, with the other two modes being available in the case of a failure of the main unit or in the case of inter-unit communication failure. However, according to this example, more options are available for controlling the motor. The examples provided provide an advantageous backup in the event of a malfunction of communication between the main unit or units. When controlling the main unit 5, the control units 10 are so-called. slave type, that is, the following commands of the main unit 5.

Fig. 11 illustrates this fault condition in the communication between the main unit 5 and the control units 10. However, the system can still be controlled in two modes, one of which communicates between the control units 10 and the other is implemented without communication between them.

Fig. 12 illustrates a situation in which control is effected without any communication between control units 10.

Fig. 13 shows a control unit for controlling the fuel supply in the example of Figs. 10-12. The control modules 100A-100C differ from Figure 6 in that the main control data of the main unit is received in the control modules 100A-100C. With this system, control modules 100A-100C can also be controlled in a known manner.

Another difference is that Fig. 13 shows a separate reference data handler 620. The reference data handler 620 performs at least some of the functions previously described for execution in the local rate reference generator 130. The change in the data stream may be provided by the change of the indication data in the communication devices 60.

Fig. 14 is a flow diagram illustrating a control method for adjusting the fuel feed in the example of Fig. 13. This embodiment differs from that shown in Fig. 7 in that the state of communication from the main unit is also determined. By defining the communication mode, the system can be used in three modes, i.e. master unit mode, isochronous mode or droop mode.

It should be noted that at least some of the functions of the control modules 100 are performed by a method implementing a program integrated with the control unit.

From the foregoing description and examples, it is obvious that the inventive embodiment can be created using a variety of different solutions. Obviously, the invention is not limited to the examples mentioned in the text, but may be practiced in many other different embodiments.

Thus, any embodiment of the invention can be implemented within the scope of the inventive idea.

Claims (6)

A method of adjusting fuel supply to an internal combustion engine, the method comprising: receiving engine speed measurement data (41) and speed reference data (62, 132) to two or more control units (10) comprising control modules (100); estimating cylinder-specific load data (61) from cylinder-specific fuel feed control data (11); cylinder specific load data (61) for export control modules (100); calculating an average of the load data (112) of the control modules (100) from the cylinder-specific load data (61); determining a load deviation value (122) of said control module (100) by comparing the cylinder specific load data (61) of said control module (100) with the average load data (112) of the control modules (100); selecting one cylinder-specific speed reference data (132) to be used as the speed reference data (62); generating a new cylinder-specific speed reference data (132) by affecting the speed reference data (62) with a defined load distribution deviation value (122); and adjusting the fuel feed based on the new cylinder-specific speed reference data (132). Method according to claim 1, characterized in that the highest value per cylinder reference speed data 132 is selected as the speed reference data to be used (62). The method according to claim 1 or 2, characterized in that the transferred cylinder-specific speed reference data (132) further comprises a data part for identifying the control state of the cylinder in question. Method according to claim 3, characterized in that the data part is adapted to determine the control mode of the cylinder in question. A method according to claim 4, characterized in that the data section assigns priority to the selection of cylindrical velocity reference data (132) such that the cylindrical velocity reference data (132) having another control mode is selected even if it does not have the highest cylindrical velocity reference 132. A fuel supply control unit for a combustion engine, comprising speed data receiving means (40) for receiving engine speed measurement data (41); communication devices (60) to be connected to the communication bus (6) for establishing a connection between the control units (10); and a control module (100) providing specific fuel supply control data (11), and the control module (100) comprising an estimator (150) for estimating cylinder specific load data (61) based on the cylinder specific fuel supply control data (11); a calculator (110) arranged to determine an average of the load data (112) of the control modules; a comparator (120) for determining a load offset value (122) of said control modules (100) by comparing the cylinder specific load data (61) of said control module (100) with the average load data (112) of the control modules; a local rate reference generator (130) configured to produce cylinder-specific rate reference data (132) by influencing the rate reference data (62) with a determined load offset value (122); and a regulator (140) configured to provide specific fuel feed control data (11) to regulate fuel feed based on said cylinder-specific speed reference data (132) and engine speed measurement data (41), characterized in that the control unit further comprises means for selecting where the adjustment is selected as fixed.