Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/22—Safety or indicating devices for abnormal conditions
  • F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/3809—Common rail control systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/3809—Common rail control systems
  • F02D41/3836—Controlling the fuel pressure
  • F02D41/3845—Controlling the fuel pressure by controlling the flow into the common rail, e.g. the amount of fuel pumped
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/3809—Common rail control systems
  • F02D41/3836—Controlling the fuel pressure
  • F02D41/3863—Controlling the fuel pressure by controlling the flow out of the common rail, e.g. using pressure relief valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/20—Output circuits, e.g. for controlling currents in command coils
  • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
  • F02D2041/2024—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit the control switching a load after time-on and time-off pulses
  • F02D2041/2027—Control of the current by pulse width modulation or duty cycle control
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/22—Safety or indicating devices for abnormal conditions
  • F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
  • F02D2041/223—Diagnosis of fuel pressure sensors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/22—Safety or indicating devices for abnormal conditions
  • F02D2041/227—Limping Home, i.e. taking specific engine control measures at abnormal conditions
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/06—Fuel or fuel supply system parameters
  • F02D2200/0602—Fuel pressure
  • F02D2200/0604—Estimation of fuel pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2250/00—Engine control related to specific problems or objectives
  • F02D2250/31—Control of the fuel pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/20—Output circuits, e.g. for controlling currents in command coils
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
  • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
  • F02D41/2409—Addressing techniques specially adapted therefor
  • F02D41/2422—Selective use of one or more tables

Definitions

• the invention relates to a method for controlling and regulating a
• a rail pressure control loop comprises a reference junction for determining a control deviation, a pressure regulator for calculating a control signal, the controlled system and a
• the controlled system comprises the pressure actuator, the rail and the injectors for injecting the fuel into the combustion chambers of the internal combustion engine.
• a common rail system with pressure control in which the pressure regulator accesses via the control signal to a suction throttle.
• the suction throttle is controlled in negative logic, that is, it is fully open at a current value of zero amperes.
• a passive pressure relief valve is provided as a protective measure against excessive rail pressure. If the rail pressure exceeds a critical value, for example 2400 bar, the pressure relief valve opens. The fuel is then discharged from the rail into the fuel tank via the opened pressure relief valve.
• Pressure relief valve adjusts itself in the rail a pressure level, which of the Injection quantity and the engine speed depends. At idle, this pressure level is about 900 bar, while at full load it is about 700 bar.
• transition function is provided. This transition function is previously determined in normal operation from the time course of the control deviation of the rail pressure. With the end of normal operation is then the pressure regulator by the
• Transition function specified a negative control deviation.
• the control path is given a correction volume flow.
• Central idea of the invention is to produce a stable operating state after failure of the rail pressure sensor in emergency operation, that a conscious opening of the passive pressure relief valve is brought about. When open
• Pressure relief valve in turn is the rail pressure between the pressure value at idle, z. B. 900 bar, and the pressure value at full load, z. B. 700 bar.
• the uniform engine power in emergency operation is achieved by the fact that the rail pressure in emergency operation is always within this pressure range. An advantage is therefore a stable emergency operation.
• a desired current is set as the drive signal of the suction throttle or a PWM signal as the drive signal of the suction throttle to a corresponding Notlaufwert.
• a supplementary embodiment provides that when switching to emergency operation, the setpoint current is calculated as a function of a leakage volume flow. This is calculated via a leakage map depending on the target injection quantity and the engine speed.
• the energization duration of the injectors is additionally adapted.
• the energization duration is calculated via a characteristic field as a function of the desired injection quantity and the actual rail pressure.
• a mean rail pressure is set as the input variable for the characteristic map.
• the mean rail pressure is specified as a constant value. If, for example, the pressure level in the rail at idle is 900 bar and 700 bar at full load when the passive pressure relief valve is open, the average rail pressure is set to 800 bar.
• the procedure according to the invention can also be used in a common rail system with an electrically actuatable high-pressure pump. If the rail pressure sensor is defective, the high-pressure pump will then open during emergency operation
• FIG. 1 shows a system diagram
• FIG. 2 shows a rail pressure control circuit in a first embodiment
• FIG. 4 shows a second block diagram
• FIG. 5 shows a rail pressure control circuit in a second embodiment
• FIG. 6 is a first block diagram
• FIG. 7 shows a second block diagram
• FIG. 8 shows a pump curve with limit curve
• FIG. 9 shows a block diagram for calculating the energization duration
• FIG 11 is a program flowchart for the first embodiment
• FIG. 12 shows a program flow chart for the second embodiment.
• the common rail system comprises the following mechanical components: a low-pressure pump 3 for
• High-pressure pump 5 for conveying the fuel under pressure increase, a rail 6 for storing the fuel and injectors 7 for injecting the fuel into the combustion chambers of the internal combustion engine 1.
• the common rail system can also be designed with individual memories, in which case, for example, in the injector 7 a Single memory 8 is integrated as an additional buffer volume.
• a passive pressure relief valve 11 is provided which opens, for example, at a rail pressure of 2400 bar and abgrest the fuel from the rail 6 into the fuel tank 2 in the open state.
• the operation of the internal combustion engine 1 is determined by an electronic control unit (ECU) 10.
• the electronic control unit 10 includes the usual
• Components of a microcomputer system such as a microprocessor, I / O devices, buffers and memory devices (EEPROM, RAM).
• EEPROM electrically erasable programmable read-only memory
• RAM random access memory
• Memory chips are the relevant for the operation of the internal combustion engine 1 operating data applied in maps / curves. About this calculates the
• the electronic control unit 10 from the input variables the output variables.
• the following input variables are shown by way of example in FIG. 1: the rail pressure pCR, which is measured by means of a rail pressure sensor 9, an engine speed nMOT, a signal FP for output specification by the operator and an input variable EIN.
• FIG. 2 shows a rail pressure control circuit 12 for regulating the rail pressure pCR in a first embodiment.
• the input variables of the rail pressure control circuit 12 are: a
• Target rail pressure pCR (SL), a target consumption Wb, the engine speed nMOT, a signal SD and a quantity El
• the signal SD is set when a malfunction of the rail pressure sensor is detected.
• E1 for example, the PWM fundamental frequency
• the output of the rail pressure control circuit 12 is the raw value of the rail pressure pCR.
• the actual rail pressure pCR (IST) is calculated by means of a filter 13. This is then compared with the desired rail pressure pCR (SL) at a summation point A, resulting in a control deviation ep.
• a pressure regulator 14 calculates its control variable, which corresponds to a regulator volume flow VR with the physical unit liters / minute.
• the calculated target consumption Wb is added to a summation point B.
• the target consumption Wb is calculated as a function of a desired injection quantity and
• the functional block 17 is shown and explained in detail in conjunction with FIGS. 3 and 4.
• the output variable of the functional block 17 corresponds to the actual volume flow V (IST) which is conveyed by the high-pressure pump into the rail 6.
• the pressure level pCR in the rail is detected by the rail pressure sensor.
• FIG. 3 shows the functional block 17 of FIG. 2 in a first block diagram.
• the PWM signal to control the suction throttle and the switching of the drive signal of the suction throttle from normal operation to emergency operation are set.
• the input variables of the functional block 17 here are the nominal current i (SL), a nominal emergency current iN (SL), the signal SD and the input quantity E1.
• the output variable of the function block 17 is the actual volume flow V (IST) actually conveyed into the rail.
• the elements of the functional block 17 are a switch S1, a calculation 18 of the PWM signal and the high pressure pump and suction throttle as a unit 19.
• the switch S1 is in the position 1, that is, the PWM signal PWM is calculated via the calculation 18 in response to the desired current i (SL). With the PWM signal PWM then the solenoid of the suction throttle is applied.
• the path of the magnetic core is changed, whereby the flow rate of the high-pressure pump is influenced freely.
• the suction throttle is normally open and is acted upon with increasing PWM value in the direction of the closed position.
• the calculation 18 of the PWM signal can be subordinated to a current control loop 20 with filter 21, as is known from DE 10 2004 061 474 A1.
• the PWM signal PWM is calculated as a function of the nominal run-flat current iN (SL).
• Fuel tank is heated less.
• FIG. 5 shows the rail pressure control circuit 12 in a second embodiment.
• the input variables of the rail pressure control circuit 12 are: the desired rail pressure pCR (SL), the input quantity E1 and an input quantity E2.
• the size E1 includes, for example, the basic PWM frequency, the battery voltage and the ohmic resistance of the intake throttle coil with supply line, which are included in the calculation of the PWM signal.
• the input quantity E2 includes, among other things, the desired consumption Wb, the engine speed nMOT and a desired injection quantity.
• the output of the rail pressure control circuit 12 is the raw value of the rail pressure pCR. From the raw value of the rail pressure pCR, the actual rail pressure pCR (IST) is calculated by means of the filter 13.
• the pressure regulator 14 calculates its manipulated variable, that is, the regulator volume flow VR with the physical unit liters / minute.
• the regulator volume flow VR is a
• the output of the function block 17 corresponds to the desired current i (SL), which is a is the input of the calculation 18 of the PWM signal.
• the calculation 18 of the PWM signal may be underlaid by a current control loop 20 with filter 21.
• the suction throttle is then applied to the PWM signal PWM, which is combined with the high-pressure pump in the unit 19.
• the output quantity of the unit 19 corresponds to the actual volume flow V (IST) conveyed by the high-pressure pump into the rail 6.
• the pressure level pCR in the rail is detected by the rail pressure sensor.
• the rail pressure control circuit 12 is closed.
• FIG. 6 shows functional block 17 of FIG. 5 in a first block diagram. If the rail pressure sensor fails, it switches from the pump characteristic to a limit curve.
• the input variables of the function block 17 are the regulator volume flow VR, which corresponds to the manipulated variable of the pressure regulator, the desired consumption Wb, the engine speed nMOT and the signal SD.
• the output quantity corresponds to the nominal current i (SL).
• SL nominal current
• the output of the switch S2 and the target consumption Wb are added.
• the result corresponds to the unlimited nominal volume flow Vu, which is then limited via the limit 15 as a function of the engine speed nMOT.
• the output quantity corresponds to the nominal volume flow V (SL), which is the input variable of both the pump characteristic curve 16 and the limit curve 22.
• the switch S1 In normal operation, the switch S1 is in the position 1, which in turn means that the desired current i (SL) is determined via the pump characteristic 16. If a defective rail pressure sensor is detected, the signal SD is set, whereby the switch S1 changes to position 2. The desired current i (SL) is now determined via the limit curve 22.
• the pump characteristic curve 16 and the limit curve 22 are shown in FIG. 8 and will be explained in more detail in connection therewith. The embodiment of FIG. 6 minimizes the heating of the fuel. If the signal SD is set, the switch S2 changes from position 1 to position 2. The controller volume flow VR is thereby replaced by the value zero.
• FIG. 7 shows the functional block 17 of FIG. 5 in a second block diagram.
• the function block has been supplemented by a leakage map 23 with the desired injection quantity Q (SL) as a further input variable.
• the switches S1 and S2 are in the position 1.
• the setpoint current i (SL) is calculated via the pump characteristic curve 16 as a function of the setpoint volume flow V (SL).
• the setpoint volume flow V (SL) is determined from the unlimited setpoint volume flow Vu, which is the sum of the regulator volume flow VR and the setpoint Consumption Wb corresponds. If a defective rail pressure sensor is detected, the signal SD is set, causing the switches S1 and S2 to change to position 2.
• Engine speed nMOT calculated.
• a leakage map and its definition is described in DE 101 57 641 A1, to which reference is hereby made.
• the desired current i (SL) is calculated via the limit curve 22.
• the abscissa represents the nominal volume flow V (SL) in liters / minute.
• the nominal current i (SL) is plotted in amperes on the ordinate.
• the pump characteristic 16 is shown as a solid line.
• High pressure pump to high pressure pump is very large, it is in the pump characteristic 16 is a mean pump characteristic.
• the two dashed lines 24 and 25 represent the scattering band within which the high-pressure pumps must be located.
• a desired volume flow V (SL) V1
• a scattering di (ST) of the setpoint current i (SL) results.
• the limit curve 22 is shown as a dashed line. This results from the fact that the pump characteristic 24 is shifted to smaller desired current values, ie in the direction of the abscissa, taking into account a reserve. For the set volume flow V1, this results in a reserve di (Re) in the energization.
• the limit curve 22 represents an assignment of the setpoint volume flow to those maximum values of the setpoint flow i (SL) which reliably enable an opening of the pressure-limiting valve.
• FIG. 9 shows a block diagram for calculating the energization duration BD.
• the energization duration BD results here as the output variable of a 3-dimensional injector map 26.
• Its input variables are the desired injection quantity Q (SL) and a pressure pINJ.
• the switch S1 In normal operation, the switch S1 is in position 1, so that the pressure pINJ is identical to the actual rail pressure pCR (IST). In case of failure of the rail pressure sensor, the switch S1 is reversed via the signal SD in the position 2.
• the pressure pINJ is set to a mean rail pressure pCR (M).
• the mean rail pressure pCR (M) corresponds to the rail pressure, which occurs on average when the pressure relief valve opens.
• Accuracy can be calculated. It is advantageous that the internal combustion engine can thus be operated in emergency mode with very high power.
• FIG. 10 shows a time diagram.
• FIG. 10 consists of the partial diagrams 10A to 10D. These each show over time: the signal SD in FIG. 10A, the desired current i (SL) in FIG. 10B, the actual rail pressure pCR (IST) in FIG. 10C and the pressure pINJ as the input variable of the injector map in FIG. 10D.
• the defect of the rail pressure sensor occurs, that is, the signal SD is set to the value 1.
• the suction throttle is fully open, so that the high-pressure pump delivers the maximum possible amount of fuel. This causes the actual rail pressure pCR (IST) from the pressure level at time t1
• FIG. 11 shows a program flow chart of a subroutine which corresponds to the embodiment according to FIGS. 2 to 4.
• S1 it is checked whether the rail pressure sensor is defective. If this is not the case, query result S1: no, the program part is run through with the steps S2 to S6.
• the regulator volume flow VR is calculated as the manipulated variable at S2 from the control deviation of the rail pressure via the pressure regulator.
• the target consumption Wb determined from the target injection quantity and the engine speed and then calculated at S4 via summation of the unlimited nominal volume flow Vu. Thereafter, this is at S5 depending on
• the alternative in which the PWM signal is set to the PWM emergency value PWMNL is shown in dashed lines as step S8A. Corresponding to this alternative, the figure 4.
• FIG. 12 shows a program flow chart of a subroutine which corresponds to the embodiment according to FIGS. 5 and 7.
• S1 it is checked whether the rail pressure sensor is defective. If this is not the case, query result S1: no, the program part is run through with the steps S2 to S6.
• the steps S2 to S6 correspond to the steps S2 to S6 of FIG. 11, ie the normal operation, so that what is said there also applies here. If a faulty rail pressure sensor was detected at S1,
• Query result S1 yes, then at S8 a leakage volume flow VLKG is calculated as a function of the desired injection quantity Q (SL) and the engine speed nMOT via a leakage characteristic map. Following this, the desired consumption Wb is determined at S9 and the unlimited desired volume flow Vu is calculated from the sum of the leakage volume flow VLKG and the desired consumption Wb, S10. At S1 1, this is limited depending on the engine speed and set as the desired flow rate V (SL). Subsequently, at S12, the setpoint current i (SL) is calculated via the limit curve and from this the PWM signal for controlling the intake throttle is determined, S7. Thereafter, the subroutine is ended. reference numeral
• ECU electronice control unit

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Fuel-Injection Apparatus (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2009
  • 2009-10-23 DE DE102009050468.0A patent/DE102009050468B4/de active Active
• 2010
  • 2010-10-19 WO PCT/EP2010/006382 patent/WO2011047833A1/de active Application Filing
  • 2010-10-19 CN CN201710718475.8A patent/CN107448315B/zh active Active
  • 2010-10-19 US US13/503,580 patent/US8886441B2/en active Active
  • 2010-10-19 CN CN201080047926.6A patent/CN102713220B/zh active Active
  • 2010-10-19 EP EP10768697A patent/EP2491237A1/de not_active Withdrawn

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