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
  • F02D41/02—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
  • F02D41/1406—Introducing closed-loop corrections characterised by the control or regulation method with use of a optimisation method, e.g. iteration
• • 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
  • F02D2041/1412—Introducing closed-loop corrections characterised by the control or regulation method using a predictive controller
• • 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
  • F02D2041/1433—Introducing closed-loop corrections characterised by the control or regulation method using a model or simulation of the system
• • 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
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
• • 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
• • 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
  • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
• • 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
  • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
  • F02D41/401—Controlling injection timing

Definitions

• the invention relates to a method for model-based control and regulation of a
• Combustion model Injection system setpoint values for controlling the injection system actuators and via a gas path model Gas path setpoint values for controlling the gas path actuators are calculated.
• Calculated internal combustion engine for example, the start of injection and a required rail pressure. These characteristics / maps are fitted with data at the manufacturer of the internal combustion engine on a test bench. The multiplicity of these characteristic curves / maps and the correlation of the
• DE 10 2006 004 516 B3 describes a Bayes network with probability tables for determining an injection quantity
• US 2011/0172897 A1 describes a method for adapting the start of injection and injection quantity via combustion models by means of neural networks.
• Critical here is that only trained data are mapped, which must be learned only at a test bench run.
• a model-based control method for the gas path of an internal combustion engine is known.
• the gas path includes both the air side and the exhaust side together with an exhaust gas recirculation.
• a first step of the process is from the
• Measured variables of the gas path for example, the charge air temperature or the NOx concentration, the current operating situation of the internal combustion engine detected.
• a quality measure within a prediction horizon is then likewise calculated from the measured variables via a physical model of the gas path. From the quality measure and the operating situation turn then in a third step the
• Control signals for the actuators of the gas path set refers exclusively to the gas path and is based on a linearized gas path model. Due to the linearization a loss of information is unavoidable.
• the invention is therefore based on the object to develop a method for model-based control and regulation of the entire engine at high quality.
• the method is that depending on a desired torque on a
• Combustion model Injection system setpoint values for controlling the injection system actuators and via a gas path model Gaspath setpoints for controlling the gas path actuators are calculated and that an optimizer calculates a quality measure as a function of the injection system setpoints and the gas path setpoints. Furthermore, the method consists in the optimizer minimizing the quality measure by changing the injection system setpoint values and gas path setpoint values within a prediction horizon and setting the injection system setpoint values and gas path setpoint values as relevant for setting the operating point of the internal combustion engine by the optimizer on the basis of the minimized quality measure become.
• the minimized quality measure is calculated by the optimizer calculating a first quality measure at a first point in time, forecasting a second quality measure within the prediction horizon at a second time, and then a deviation of the two
• Quality measures is determined. If the deviation is smaller than a limit value, then the optimizer sets the second quality measure as a minimized quality measure.
• the limit value analysis is a termination criterion insofar as further minimization would not lead to any more precise adaptation. Instead of the limit value analysis, a predefinable number of
• Recalculations are set as abort criterion.
• a setpoint rail pressure value for a subordinate rail pressure control loop and immediately an injection start and an injection end for controlling an injector are then specified by the optimizer as an injection system setpoint.
• the optimizer indirectly then the gas path setpoints, for example, a lambda setpoint for a subordinate lambda control loop and an EGR setpoint for a
• Both the combustion model and the gas path model map the system behavior of the internal combustion engine as mathematical equations. These are determined once based on a reference internal combustion engine at a test bench run, the so-called DoE test bench run (DoE: Design of Experiments) or from simulation experiments. Since, for example, different emission targets for one and the same type of engine can be displayed, the coordination effort is significantly reduced. A distinction between a stationary and a transient operation, for example, in a load application in the
• the target torque is set precisely while maintaining the emission limit value.
• the models are individually tunable, the models in the sum of the internal combustion engine. The previously required characteristics and maps can thus be omitted.
• FIG. 1 shows a system diagram
• FIG. 2 shows a model-based system diagram
• FIG. 3 is a program flowchart
• FIG. 1 shows a system diagram of an electronically controlled internal combustion engine 1 with a common rail system.
• the common rail system includes the following mechanical
• a low-pressure pump 3 for conveying fuel from a fuel tank 2, a variable intake throttle 4 for influencing the flowing through
• Fuel volume flow a 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.
• a 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.
• Common Railsystem be executed with individual memories, in which case, for example, in Injector 7 a single memory 8 is integrated as an additional buffer volume.
• Injector 7 a single memory 8 is integrated as an additional buffer volume.
• the illustrated gas path includes both the air supply and the exhaust gas removal.
• Intercooler 12 a throttle valve 13, a junction 14 for merging the charge air with the recirculated exhaust gas and the inlet valve 15.
• an EGR actuator 17 the turbine of the
• the operation of the internal combustion engine 1 is determined by an electronic control unit 10 (ECU).
• 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).
• I / O devices I / O devices
• buffers and memory devices EEPROM, RAM
• EEPROM electrically erasable programmable read-only memory
• FIG. 1 A setpoint torque M (SET), which is predetermined via an operator, the rail pressure pCR, which is measured by means of a rail pressure sensor 9, the engine speed nIST, the charge air pressure pLL, the charge air temperature TLL, the humidity phi of the charge air, the exhaust gas temperature TAbgas, the air-fuel ratio lambda, the NOx actual value, optionally the pressure pES of the individual memory 8 and a
• SET setpoint torque M
• SET setpoint torque M
• the rail pressure pCR which is measured by means of a rail pressure sensor 9
• the engine speed nIST the charge air pressure pLL
• the charge air temperature TLL the humidity phi of the charge air
• Control of the intake throttle 4 a signal ve to control the injectors 7 (start of injection / injection end), a control signal DK to control the throttle valve 13, a control signal AGR to control the EGR actuator 17, a control signal TBP to control the turbine bypass valve 18 and an output size OFF.
• the output variable OFF is representative of the further control signals for controlling and regulating the internal combustion engine 1,
• FIG. 2 shows a model-based system diagram.
• a combustion model 19 within the electronic control unit 10, a combustion model 19, a gas path model 20 and a Optimizer 21 is listed.
• Both the combustion model 19 and the gas path model 20 map the system behavior of the internal combustion engine as mathematical equations.
• the combustion model 19 statically maps the combustion processes.
• the gas path model 20 forms the dynamic behavior of the air duct and the
• Combustion model 19 includes single models, for example, for NOx and soot formation, exhaust gas temperature, exhaust gas mass flow, and peak pressure. These individual models in turn depend on the boundary conditions in the cylinder and the parameters of the injection.
• the combustion model 19 is determined in a reference internal combustion engine in a test bench run, the so-called DoE test bench run (DoE: Design of Experiments). The DoE test bed run becomes systematic
• the optimizer 21 evaluates the combustion model 19 with regard to the
• Target torque M SOLL
• the emission limit values for example the humidity phi of the charge air
• the environmental boundary conditions for example the humidity phi of the charge air
• the operating situation of the internal combustion engine is defined by the engine speed nIST, the charge air temperature TLL, the
• the function of the optimizer 21 is now to evaluate the injection system setpoints for controlling the injection system actuators and the gas path setpoints for controlling the gas path actuators.
• the optimizer 21 selects that solution in which a quality measure is minimized.
• the quality measure is calculated as the integral of the quadratic nominal-actual deviations within the prediction horizon. For example, in the form:
• w1, w2 and w3 denote a corresponding weighting factor.
• the nitrogen oxide emission results from the humidity phi of the charge air, the charge air temperature, the start of injection SB and the rail pressure pCR.
• the quality measure is minimized by calculating a first quality measure from the optimizer 21 at a first point in time, varying the injection system setpoint values and the gas path setpoints, and using this a second quality measure within the prediction horizon is forecasted. On the basis of the deviation of the two quality measures each other, the optimizer 21 determines a minimum quality measure and sets this as relevant for the
• the target rail pressure pCR (SL) is the reference variable for the subordinate rail pressure control loop 22.
• the manipulated variable of the rail pressure control loop 22 corresponds to the PWM signal for acting on the suction throttle.
• the injector (FIG. 1: 7) is acted upon directly by the start of injection SB and the injection end SE.
• the optimizer 21 indirectly determines the gas path setpoints. In the illustrated example, these are a lambda setpoint LAM (SL) and an EGR setpoint AGR (SL) for specification for the two subordinate control loops 23 and 24.
• the returned measured variables MESS are read in by the electronic control unit 10.
• the measured quantities MESS are to be understood as meaning directly measured physical quantities as well as auxiliary variables calculated therefrom.
• the actual lambda value LAM (ACTUAL) and the EGR actual value AGR (ACTUAL) are read in.
• FIG. 3 shows the method in a program flow chart.
• Initialization at S 1 is checked at S2 whether the starting process is completed. If this still runs, query result S2: no, branches back to point A. If the starting process has ended, then at S3 the setpoint torque M (DESIRED), which can be predetermined by the operator, and the NOx setpoint value NOx (SOLL) are read in. Following this, at S4 the operating situation of the
• the operating situation is defined by the measured variables, in particular by the engine speed nIST, the charge air temperature TLL, the charge air pressure pLL, the wet phi of the charge air, etc.
• the subroutine optimizer is called and the initial values, for example the injection start SB, are generated at S6.
• a first quality measure Jl is calculated using equation (1) at S7, and a running variable i is set to zero at S8. After that, the initial values are changed at S9 and calculated as new setpoint values for the manipulated variables.
• the run variable i is increased by one.
• a second quality measure J2 is then predicted for Si within the prediction horizon, for example for the next 8 seconds.
• the second quality measure J2 is subtracted from the first quality measure J1 and compared with a limit value GW.
• a limit value GW is checked about the difference of the two quality measures.
• the further progress of the quality measure is checked.
• the two threshold considerations are one
• Query result S12 no, it branches back to point C. Otherwise, at S13 the optimizer sets the second quality measure J2 as a minimum quality measure J (min). From the minimum quality measure J (min), the injection system setpoint values and the gas path setpoint values then result for the specification for the corresponding actuators. Following this, S 14 checks whether an engine stop has been initiated. If this is not the case, query result S14: no, branch back to point B. Otherwise, the program schedule is finished.
• FIG. 4 shows a time diagram.
• FIG. 4 comprises FIGS. 4A to 4D.
• Figure 4A shows the course of the nitrogen oxide emission NOx
• Figure 4B shows the course of the nitrogen oxide emission NOx
• the time range before to is the past.
• the prediction horizon for example 8s, corresponds to the time range t0 to t0 + tp.
• ts is a calculation time designated at which a new setpoint, for example, the injection start SB, is output from the electronic control unit.
• SOLL constant setpoint torque M
• the NOx target value course NOx (SL) in FIG. 4A is predetermined. From these initial values results a correspondingly large desired actual deviation dNOx, see FIG. 4A.
• the NOx actual value is calculated as a function of the measured air pressures in the air path and the start of injection SB. Using equation (1), the optimizer calculates a first quality measure J1 at time t0. The optimizer then calculates how a change in the start of injection SB, the desired lambda value, is calculated
• the optimizer determines the second quality measure J2 for each of the times shown. About the subtraction of the two quality measures and the
• EGR actuator exhaust gas recirculation

Landscapes

• 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)
• Combined Controls Of Internal Combustion Engines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62683185

Family Applications (1)

Country Status (4)

Families Citing this family (5)

Family Cites Families (16)

• 2017
  • 2017-06-20 DE DE102017005783.4A patent/DE102017005783B4/de active Active
• 2018
  • 2018-06-12 WO PCT/EP2018/065457 patent/WO2018234093A1/de unknown
  • 2018-06-12 CN CN201880041639.0A patent/CN110741148B/zh active Active
  • 2018-06-12 EP EP18732291.2A patent/EP3642467A1/de not_active Withdrawn

Also Published As

Similar Documents

Legal Events