DE102007000479A1 - Supercharging pressure controller for combustion engine controlling system, has turbine provided in engine exhaust system and exhaust gas drive magnitude evaluation device for evaluating exhaust gas drive magnitude components of compressor - Google Patents

Abstract

The supercharging pressure controller has a turbine (31) which is provided in a combustion engine exhaust system. An exhaust gas drive magnitude evaluation device is for evaluating an exhaust gas drive magnitude components of the compressor (22) on the basis of the supercharging pressure value by the compressor. The supercharging pressure value is evaluated by the supercharging pressure magnitude evaluation device and the supercharging pressure variation magnitude obtained by the load pressure variation magnitude recovery device.

Description

The The present invention relates to a boost pressure control, which relates to Controlling a boost pressure of an internal combustion engine is used and more particularly, a boost pressure control used in an engine control system used with a turbocharger and a support device, such as. an electric motor, is equipped.

Of the Turbocharger is composed of a turbine and a compressor, which are provided at the two respective ends of a rotary shaft, and the turbine rotates in an engine exhaust system is arranged, by an exhaust gas flow, to that in an internal combustion engine intake system to drive arranged compressor by the power to thereby Supply air (charge air) with a pressure to an internal combustion engine, the higher than an atmospheric one Pressure is. A turbocharger having an electric motor (a boost pressure changing device), the at a rotating shaft of the turbocharger for supporting the Drive the turbocharger is mounted, has already been developed. In such a turbocharger with the electric motor becomes a supportive power on the rotary shaft of the turbocharger through the support motor in a transition period from a low speed range to a high speed range of the internal combustion engine (when accelerating) applied and thereby the characteristics the internal combustion engine to be improved during startup.

However, it is important to calculate an amount of driving by the exhaust gas flow (driving amount exhaust gas component) from the driving amount of the compressor in the case of controlling a supercharging pressure in the turbocharger with the electric motor or the like. Therefore, the following procedure is used. Namely, for controlling the boost pressure to a target value (a target boost pressure), a target drive amount (a drive amount required) of the assist motor is calculated as a difference between the target drive amount and the exhaust gas drive amount component of the compressor
(Target drive amount - exhaust gas drive amount component).

JP-2006-22763A for example, discloses an apparatus using such a method of controlling a boost pressure. In this apparatus, components of an engine exhaust system are selectively modeled to build a simulated (virtual) engine control system in software to thereby determine various parameters used for boost control, including the exhaust propulsion amount component, through various calculations. The following is with reference to 9 an overview of this device explained. 9 Fig. 12 is a block diagram showing a design example with reference to models related to system components as the basis of control programs in this apparatus.

As in 9 is shown, this device is composed of a respective program in which a respective component of the engine control system is modeled. Specifically, control programs related to control of boost pressure are generated based on a respective model of an exhaust pipe and an intake pipe (exhaust pipe model M61 and intake pipe model M65) and a respective model relating to a turbine, a rotary shaft and a compressor of the compressor Turbocharger (turbine model M62, shaft model M63 and compressor model M64). These control programs are installed as a virtual engine control system in, for example, an ECU (electric control unit) for an engine control.

In this apparatus, an amount of driving by an exhaust gas flow (exhaust gas drive amount component) is given from the driving amount of the compressor by the respective model (more specifically, a program according to the respective model) based on an input of parameters related to engine operating conditions, such as an exhaust gas amount EGQ and an engine speed NE. Namely, the power (the turbine power) used for driving the turbine is calculated from the power generated according to the engine operating conditions, in particular, the power of the exhaust gas flow through the exhaust pipe model M61 and the turbine model M62. Then, the power from the turbine power used for charging (compressor power) is calculated by the shaft model M63 and the compressor model M64. At this time, compressor efficiency (driving efficiency) is determined taking into consideration parameters relating to the intake air at the upstream side of the compressor (intake air amount IAQ, intake air temperature IAT and intake air pressure IAP), and the compressor power is calculated based on this efficiency. The parameters related to the intake air at the upstream side of the compressor are calculated by the intake pipe model M65 representing a deceleration or the like for the air (intake air) taken in an engine intake system. In this device, the compressor capacity corresponding to the is calculated, the exhaust gas drive amount component. This exhaust gas drive amount component is used to control the boost pressure, and for example, the drive of the assisting motor is controlled on the basis of this exhaust gas drive amount component.

In this way, the above-mentioned apparatus can also calculate the driving amount by the exhaust gas flow (the exhaust gas driving amount component) from the driving amount of the compressor. However, to meet strict exhaust emission regulations, a complicated exhaust system has been adopted for the purpose of purifying exhaust emissions. On the other hand, in this device, as in 9 12, the exhaust gas drive amount component is calculated mainly based on sections (programs) modeled in an engine exhaust system. Therefore, in the case where such a device is applied to the complicated exhaust system, a large-scale model scale and a complicated model construction are unavoidable. As a result, the mapping as a model (the execution of each model) becomes difficult, and a calculation cost by the executed model becomes extremely high. Therefore, the problem arises of increasing calculation loads or deteriorating calculation accuracy.

in the In view of the above, there is a need for one Boost pressure control, the problems mentioned in the prior art mastered the technology. The present invention addresses this need in the prior art Technology and equally directed to other necessities that the One skilled in the art will be apparent from this disclosure.

It It is an object of the present invention to provide a boost pressure control to create the computational burdens or calculation errors a boost pressure control can reduce even in the case that the wastegate control mounted on a complicated exhaust system becomes.

According to one Aspect of the present invention is a wastegate control used in an internal combustion engine control system having a turbocharger to perform a charge in an internal combustion engine intake system by a Compressor, which works together with a turbine, the in an internal combustion engine exhaust system is provided on the basis the drive of the turbine is moved by an exhaust gas flow. The boost pressure control also has a boost pressure changing device operated by a service that is other than that of the exhaust gas flow is to change a boost pressure. The wastegate controller calculates an exhaust gas drive amount component accordingly an amount of driving by the exhaust gas flow from a driving amount of the compressor to the boost pressure of an internal combustion engine on the Basis of the exhaust gas drive amount component to control. The boost pressure control further includes a boost pressure measuring device for measuring an actual boost pressure as Inlet pressure at a predetermined position in the engine intake system, an actual charging amount calculating device to calculate an actual load size on the Basis of the actual boost pressure by the boost pressure measuring device is measured, a boost pressure change amount obtaining device for obtaining a boost pressure change amount by the drive of the wastegate and a Abgasantriebsbestungsberechnungsvorrichtung auf for calculating a Exhaust gas drive component of the compressor based on that is actual load size through the compressor calculated by the actual charging amount calculating device and the boost pressure change amount, by the boost pressure change amount obtaining device is won.

Of the Inventor has paid attention to a point that in a previous Engine control system a construction of an engine intake system easier than that of an internal combustion engine exhaust system and an actual boost pressure, which is measured in the engine intake system, basically a Correlation to a drive amount of a compressor at a Turbocharger has. As a result, the inventor invented the construction, the exhaust gas drive amount component of the compressor without the Calculate usage of parameters of the engine exhaust system can. This construction is made to be a driving amount through an exhaust gas flow (Exhaust propulsion amount component) of a driving amount of the compressor based on an actual boost pressure in the engine intake system is measured, finally an actual load size on the Based on a drive of the compressor, by the boost pressure is obtained (the drive through all the benefits by adding performance, such as the support performance, to the performance the exhaust gas flow is obtained), and a boost pressure change amount by the drive a charge pressure changing device (for example, the assist motor) can calculate. If such a construction is assumed, can as a result, even in the case that this wastegate control on a complicated exhaust system is mounted, computational loads or calculation error in the wastegate control can be reduced.

It It should be noted that in view of the boost pressure change amount obtaining device a device for calculating and obtaining the boost pressure change amount on the basis of an instruction value of a benefit to the Boost pressure changing device is particularly advantageous.

Other Objects, features and advantages of the present invention will become from the following detailed description with reference to the attached Drawings can be seen in which similar Parts by similar Reference numerals are designated.

1 Fig. 10 is a schematic construction diagram showing an engine control system to which a wastegate control is applied in an embodiment of the present invention;

2 FIG. 13 is a block diagram showing a layout of an entire system (a model design) in the case where portions related to a boost pressure in the in-mold 1 shown shown as a model;

3 Fig. 10 is a block diagram showing a design example with reference to models related to system components as the basis of control programs in waste-pressure control;

4 Fig. 10 is a block diagram showing a detail of an intake inversion model relating to the programs;

5A . 5B and 5C Fig. 15 are diagrams each showing a detail of each model in the intake inversion model;

6 Fig. 10 is a block diagram showing a detail of a motor model and an engine reversing model related to the programs;

7 Fig. 10 is a diagram showing the process of the waste pressure control by the wastegate control;

8th is an example (a modification) of a construction using an auxiliary compressor in place of a backup motor; and

9 Fig. 12 is a block diagram showing a layout with reference to models related to system components as the basis of control programs related to the conventional wastegate control.

One embodiment The present invention will be described below with reference to FIG the attached Drawings described.

1 FIG. 10 is a construction diagram showing a schematic construction of an internal combustion engine control system for a vehicle (a passenger car) to which a wastegate control in the embodiment is applied. First, referring to 1 the overview of the system explained.

As in 1 1, this engine control system employs a four-cylinder reciprocating type internal combustion engine (an internal combustion engine). 10 as a tax object. The internal combustion engine 10 is constructed so that a piston (not shown) in each one of four cylinders 11 is housed and the pistons in order by fuel combustion in combustion chambers in the cylinders 11 walk back and forth. A reciprocating motion of the respective piston causes a crankshaft to rotate as an output shaft (not shown) provided collectively for the pistons. In addition, an inlet pipe 12 (an inlet passage) and an outlet pipe 13 (An exhaust passage) at the respective combustion chamber of the cylinder 11 located to open to the respective combustion chamber. An intake valve and an exhaust valve operated by a cam (not shown) open / close the intake pipe 12 and the outlet pipe 13 ,

The inlet pipe 12 that is part of the intake system in the internal combustion engine 10 forms is with an air purifier 21 provided on the upstream side for purifying air entering the inlet pipe 12 is recorded. A compressor 22 performing a charge as part of a turbocharger 50 , an intercooler 23 that cools intake air and an electrically controlled throttle valve (Intake throttle valve) 24 whose opening is electrically adjusted by an actuator such as a DC motor are in order of the air cleaner 21 arranged in the direction of the inlet downstream side. The inlet pipe 12 is branched off at an intake manifold, which on the inlet downstream side of the throttle valve 24 is located, and is with the combustion chamber of a respective cylinder 11 connected by the branch section. It should be noted that the intercooler 23 is a so-called intercooler of the air-cooling type, which achieves a cooling function caused by external air taken in according to a vehicle speed to a main body of the intercooler 23 meets.

On the other hand, the outlet pipe 13 with a turbine 31 provided which rotates by an exhaust gas flow. The turbine 31 is a turbine with a variable nozzle equipped with a so-called variable nozzle mechanism that changes a turbine nozzle area by a certain actuator (for example, a vacuum actuator using a vacuum portion in an engine intake / exhaust system or an electric motor), finally Loading amount by a rotation of the turbine 31 is changed.

Various exhaust aftertreatment devices are on the downstream exhaust side of the turbine 31 arranged. A DPF (Diesel Particulate Filter) 32 , a NOx catalyst 33 , a DOC (Diesel Oxidation Catalyst) 34 and further a muffler 35 namely, as sound reducers are arranged in this order from the upstream side. The DPF 32 is a PM removal filter made of a porous material to block transmission of particulate matter (PM) in the exhaust gas to trap it. The NOx catalyst 33 (A catalytic converter) is an absorption / reduction type catalyst which contains catalysts, absorbents and the like as needed and which absorbs NOx (nitrogen oxides) when an oxygen density in the exhaust gas is high, and which releases the absorbed NOx when the oxygen density in the exhaust gas is low. The DOC 34 is an oxidation catalyst containing catalysts such as platinum and which oxidizes hydrocarbon (HC) or carbon monoxide (CO) in the exhaust gas through the catalyst for purifying the exhaust gas.

Further, this system is with an EGR device 40 provided between the inlet pipe 12 and the outlet pipe 13 is to recirculate a portion of the exhaust gas to an intake system as EGR gas (exhaust gas recirculation gas). The EGR device 40 basically consists of an EGR tube 41 which is arranged so that there is a connection between the inlet pipe 12 and the outlet pipe 13 and an EGR valve 42 formed of an electromagnetic valve or the like, which is a passage area of the EGR pipe 41 with a valve opening of the same setting. The EGR pipe 41 is at the furthest upstream section with an exhaust upstream side of the turbine 31 connected in the exhaust system, and the most downstream portion is connected to the downstream side of the throttle valve 24 connected in the intake system. This system recirculates a portion of the exhaust gas to the intake system through the EGR pipe 41 as needed based on this construction of the EGR device 40 thereby lowering the combustion temperature to reduce the generation of NOx.

In addition, the turbocharger 50 that comes from the compressor 22 , the turbine 31 and the like, between the inlet pipe 12 and the outlet pipe 13 located. The turbocharger 50 has an inlet compressor 22 in the inlet pipe 12 is arranged, and the exhaust gas turbine 31 on that in the middle of the outlet tube 13 is arranged, and the compressor 22 and the turbine 31 are through a wave 51 connected. The wave 51 is with an electric assist motor 52 provided a drive of the turbocharger 50 supports, and power becomes the electric support motor 52 supplied from a battery (not shown). The wave 51 is a common output shaft of the turbocharger 50 and the backup motor 52 , At the turbocharger 50 becomes the exhaust gas turbine 31 through the exhaust gas in the outlet pipe 13 flows, and the drive (the support) of the backup motor 52 turned. The torque is through the shaft 51 on the intake compressor 52 transfer and the air in the inlet pipe 12 flows through the intake compressor 22 compacted for recharging. It should be noted that the boost pressure not only by the drive of the support motor 52 but also by the drive of the variable nozzle mechanism (the turbine 31) is changed. At this point, the charged air gets through the intercooler 23 cooled to improve a fill factor of the intake air.

It is to be noted that various sensors are used in this engine control system, but these sensors are not shown for a simplified explanation. For example, in the vicinity of the inlet upstream of the air cleaner 21 a pressure sensor for detecting an atmospheric pressure and a temperature sensor for detecting an atmospheric temperature provided. A pressure sensor is located in a surge tank in front of an intake manifold branch (downstream of the intake manifold) throttle valve 24 ) to thereby detect an intake pressure including the boost pressure. An air flow meter for detecting an amount of fresh air passing through the air purifier 21 is taken downstream of the air purifier 21 intended. An accelerator pedal sensor for detecting an accelerator pedal depression amount (accelerator pedal position) by a driver is provided on the accelerator pedal of a vehicle (not shown).

As has been described above, the construction of the engine control system explained, to which the wastegate control is applied in the embodiment. Next be the construction and operation of the boost pressure control in the embodiment explained.

The boost pressure control in the embodiment is mounted on a portion for initiating the performance of an engine control in the aforementioned system, in particular, a so-called engine ECU (electric control unit, not shown). The ECU is the assist motor with a known microcomputer (not shown) including various actuators such as a fuel injector (not shown) 52 on desired states based on detection values of various sensors, the operating conditions of the internal combustion engine 10 capture, or actuated by a request of a user to thereby perform various controls that relate to the internal combustion engine 10 Respectively. The microcomputer mounted on the ECU is basically composed of various types of a computing device, a memory device and a communication device such as a CPU performing various calculations (basic process device), a RAM (main memory) as main memory, temporarily data during computation, computation results and the like, a ROM (Read Only Memory) as a program memory, an EEPROM (Electrically Erasable Programmable Read Only Memory) constructed as a data latch and input / output terminals which input / output signals between the microcomputer and an outdoor area. Various programs and control maps relating to the engine control including the boost pressure control are stored in advance in the ROM, and various control data including design data and experimental data of the internal combustion engine 10 are stored in advance in the data holding memory (EEPROM).

In the above-mentioned system, the control of a torque is performed by a so-called torque base control. More specifically, a torque that is at this point according to an operating condition of the internal combustion engine 10 is required (a torque requirement) determined. For generating the torque requirement in the internal combustion engine 10 For example, target values of various parameters related to the torque, such as a target fuel injection amount, a target fresh air amount, and a target boost pressure, are determined to control a respective control value to the specified target value. The torque demand is calculated based on an accelerator pedal depression amount by a driver or the like. The drive of the backup motor 52 or the variable nozzle mechanism (the turbine 31 ) is controlled based on the torque requirement. More specifically, a target driving amount of the supercharging pressure changing device and, finally, an optimal drive timing thereof are calculated based on the torque demand, and also an appropriate power is supplied to the respective calculated timing device.

More specifically, for example, the assist power is applied to the rotation shaft 51 of the turbocharger 50 through the support engine 52 in a transitional period from a low speed range to a high speed range of the internal combustion engine (during acceleration), wherein the characteristics of the internal combustion engine 10 be improved during startup. In addition, in this case, similar to the device ( 9 ), in the JP-2006-22763A is described, an amount of driving (an exhaust gas drive amount component) by the exhaust gas flow from the driving amount of the compressor 22 calculated. Further, a target driving amount (driving amount required) of the assist motor becomes 52 as the difference between the exhaust gas drive amount component and a target driving amount (driving amount required) of the compressor 22 calculated according to a target boost pressure (target drive amount - exhaust gas drive amount component). Hereinafter, using a case of improving the characteristics of the internal combustion engine 10 at startup by the assist motor 52 as an example, the construction and the operation of the wastegate control further explained in the embodiment. It should be noted that the wastegate control of the embodiment is basically performed by executing programs (stored in the ROM) by the CPU. Accordingly, in particular, the construction and operation of the wastegate control in the embodiment will be described below in detail.

2 FIG. 4 is a block diagram (a conceptual diagram) showing a layout of the overall system (a model design) in the case of model sections related to the boost pressure from the combustion refer to motor control system, which in 1 is shown.

As in 2 In this case, the system consists mainly of a respective model relating to components in an exhaust system and an intake system (exhaust model M1 and intake model M4), a turbine model M2 relating to a turbine of the turbocharger, and a motor model M3, referring to the support engine 52 refers.

For example, in such a system, when the boost pressure is controlled by a method similar to the device (FIG. 9 ), which is in JP-2006-22763A are described, respective pressures before and after the turbine 31 (Inlet side and outlet side) and a temperature in front of the turbine 31 (Exhaust inlet side) is calculated in the exhaust model M1. Further, in the turbine model M2 receiving the discharge of the exhaust model M1, namely, the input of the exhaust system parameters, an exhaust gas drive amount component of the compressor 22 (Compressor drive amount by exhaust gases) calculated on the basis of the calculated exhaust system parameters. In addition, a target driving amount of the compressor 22 from a target boost pressure TP using a reversal model of the intake model M4 (model in which an output and an input are reversed with respect to those in a normal model) is calculated (dotted line L1). Further, an amount of driving the compressor 22 through the support engine 52 (a backup drive amount) is calculated as a difference amount between the target driving amount and the exhaust gas driving amount component (target driving amount - exhaust gas driving amount component).

On the other hand, in the exhaust pressure control in the embodiment, a target driving amount and an exhaust gas driving amount component of the compressor become 22 calculated by the inverse model of the inlet model M4 and the normal and inverted model of the model M3. Namely, this device allows the exhaust gas drive amount component of the compressor 22 is calculated without the use of the exhaust model M1 and the turbine model M2.

Next, referring to 3 the program arrangement of the wastegate in the embodiment described in detail. 3 Fig. 10 is a block diagram showing an example of design with reference to the models relating to system components used as the basis for the control programs.

As in 3 As shown, this device is constructed so that components of the engine control system are selectively modeled as a model and the respective programs (modules) of the modeled components are combined. More specifically, a control program relating to the control of the boost pressure is based on inversion models of the intake model M4 related to the intake system (intake inversion models RM4a and RM4b), a normal model (engine model M3) and a reverse model (engine reversal model RM3 ) of an engine model M3, which refers to the assist engine 52 and generates a holding block B1. The control program is stored in the ROM of the engine ECU as a simulated (virtual) engine control system.

In this apparatus, an amount of driving by the exhaust gas flow (an exhaust gas drive amount component) from the driving amount of the compressor by the respective model (more specifically, the program corresponding to the respective model) is calculated by using a target boost pressure TP and an actual boost pressure AP as an input. An instruction value (instruction compaction power) of a power (supply power) of the assist motor 52 that is required to control the boost pressure to the target boost pressure TP is calculated and output based on the calculated exhaust propulsion amount component. The actual boost pressure AP is detected by a pressure sensor downstream of the throttle valve 24 (For example, in a surge tank) recorded. In the embodiment, the portion for this detection corresponds to a boost pressure measuring device.

Namely, in this apparatus, the intake inversion model RM4a receives an input of the target boost pressure TP by a target driving amount QC of the compressor 22 leave (dotted line L1 in 2 ). In addition, the intake inversion model RM4b receives an input of an actual boost pressure AP by an actual driving amount NC of the compressor 22 deliver (an amount of drive of the compressor 22 through all the benefits that are gained by adding the backup power of the backup motor 52 to the power of the exhaust gas flow) (dotted line L2 in FIG 2 ). Both of the intake inversion models RM4a and RM4b are configured to receive the target driving amount QC and the actual driving amount NC formed by reproducing characteristics of the engine intake system from an actual boost pressure measuring position (here a surge tank) to the turbocharger 50 (the compressor 22 ) at the input (a target boost pressure TP and an actual boost pressure AP). In the embodiment, the actual drive amount corresponds NC to be calculated and delivered, an actual load size based on the drive of the compressor 22 ,

On the other hand, the motor model M3 gains a value by reproducing characteristics of the assist motor 52 (here, response characteristics) is formed to an instruction value (instruction compressor output) of the power (the supply power) and outputs it to the assist motor 52 as an electric motor, in particular the driving amount (assist driving amount NA) of the compressor 22 through the support engine 52 as value after playback. Further, as in 3 11, in the embodiment, the preceding value of the instruction compressor power is basically used except for the initial time. Therefore, the holding block B1, namely, a predetermined hold time (for example, 32 ms) is set between a point of calculation of the command compressor output and a point of input of the calculated result of the motor model M3 to thereby prevent a loop of the calculation process. It should be noted that, in the embodiment, the assist driving amount NA to be calculated here is a boost pressure changing amount (charging amount) based on the driving of the assisting motor 52 equivalent.

A calculating section C1 calculates an amount of driving by the exhaust gas flow (exhaust gas drive amount component NCex) from the driving amount (actual driving amount NC) of the compressor 22 as the difference between the actual driving amount and the assist driving amount NA (NC-NA). Further, a calculation section C2 outputs power to the assist motor 52 (a assist power QN) as a difference between the target drive amount QC and the exhaust gas drive amount component NCex (QC-NCex). The engine reversing model RM3, which receives the assist power QN as input, gives the characteristics of the engine 52 (here, the response characteristics) to the assist power QN again, and obtains the reproduced value as the power instruction value (command compressor output) and supplies it to the engine 52 from. This device thus obtains the command compressor output in accordance with the target boost pressure TP and the actual boost pressure AP, and controls the boost pressure to the target boost pressure TP by driving the assist motor 52 with this instruction value.

Next, referring to the 4 to 6 together with the above-mentioned drawings, explains a detail of each model (the inversion inversion models RM4a and RM4b, the engine model M3 and the engine inversion model RM3) used in the aforementioned apparatus.

4 Fig. 10 is a block diagram showing the detail of the intake inversion models RM4a and RM4b.

As in 4 is shown, the intake inversion models RM4a and RM4b have the same structure in which the components (throttle valve 24 , Intercooler 23 and compressors 22 ) of the engine intake system per component unit are shown as a module. Each module (throttle inversion model RM41, intercooler inversion model RM42, and compressor inversion model RM43) outputs a value formed by reproducing the characteristics of each component to a respective input. Inputs / outputs between the modules are connected to the models RM41, RM42 and RM43 in the order according to the design of the components of the inlet system (see 1 ). In the embodiment, components along a flow of the air (intake air or exhaust gas) or energy (components in which inputs / outputs have the same direction) are defined as normal models and become components against the flow of air or energy (components) which the inputs / outputs are in the opposite direction) are defined as reversal models, which provides for easy generation and handling of the models and programs.

With reference to the 5A to 5C explains the detail of the models RM41, RM42 and RM43. The throttle reverse model RM41 will be described with reference to FIG 5A explained.

The throttle reverse model RM41 is introduced and generated based on a formula (1) with respect to parameters related to the throttle valve 24 refer to that in 5A is shown. Here, the parameters include an air flow rate (a fresh air flow rate) Q, an upstream pressure Pthr, a downstream pressure Pim, a pressure difference ΔP thereof (Pthr-Pim), an inner diameter dc of the throttle 24a and the same. This formula (1) is based on Bernoulli's theory and uses a flow rate coefficient α, an expansion correction coefficient ε and an air density ρ in addition to the respective parameter of the throttle valve 24 ,

The Throttle reversal model RM41 is in fact according to the following Formula (2) as a mathematical model (model in which a certain Natural phenomenon described mathematically) based on the formula (1) shown as a model.

Thus, the throttle reverse model RM41 receives an input of the boost pressure downstream of the throttle valve 24 (Target boost pressure TP or actual boost pressure AP), in particular, a downstream throttle pressure Pim for outputting the upstream throttle pressure Pthr.

On the other hand, the intercooler inversion model RM42 becomes based on the characteristics of the intercooler 23 pictured as a model in the 5B and 5C are shown.

More specifically, this shows in 5B A map shown a heat release amount (discharge amount) Qe at the intercooler 23 by an air flow rate (intake air flow rate) Qa and air flowing to the intercooler 23 (amount of cooling air Qc) is affected. As in 5B is shown, the heat release amount Qe increases as the air flow rate Qa increases or the cooling air amount Qc increases. It should be noted that the cooling air amount Qc basically increases as the vehicle speed increases. Since the heat release amount Qe is also affected by an outside air temperature or the like, the heat release amount Qe can be corrected by other parameters including the outside air temperature.

On the other hand, that shows in 5C map shown a pressure drop ΔPi in the intercooler 23 (a loss amount) that changes by the air flow rate Qa (intake air passage amount). As in 5C is shown, the pressure loss PI increases as the air flow rate Qa increases.

Here is an upstream air temperature of the intercooler 320 (Almost equal to a downstream air temperature of the compressor 22 ) equal to a value obtained by subtracting a temperature loss ΔT from the downstream air temperature (almost equal to an upstream air temperature of the throttle valve 24 which is almost equal to an intake air temperature) of the intercooler 23 is created (intercooler upstream air temperature = intercooler downstream air temperature - .DELTA.T). It should be noted that a temperature loss ΔT is represented as "heat release amount [W] / specific heat of air [J / kg · K] × air flow rate [kg / s]". An upstream pressure of the intercooler 23 (Almost equal to the downstream pressure Pb of the compressor 22 ) is equal to a value obtained by subtracting a pressure loss from the downstream pressure (nearly equal to the upstream throttle pressure) of the intercooler 23 is created (intercooler upstream pressure = intercooler downstream pressure - pressure loss). Accordingly, the downstream pressure Pb of the compressor 22 calculated using the map ( 5B and 5C ).

Thus, the intercooler reversal model RM42 is modeled as a characteristic model showing a relation between a plurality of parameters (for example, a relation between an air flow rate and a pressure loss) with respect to predetermined characteristics (heat release quantity characteristic or pressure characteristic) and receives an input of the upstream throttle pressure Pthr to receive the downstream pressure Pb of the compressor 22 based on the map.

Further, the compressor inversion model RM 43 also represented as a mathematical model (formula 3). It should be noted that in the following formula (3) Ltc a power of the compressor 22 (Target drive amount QC or Actual driving amount NC of the compressor 22 ), Pa denotes an atmospheric pressure (detected by a sensor), Ta denotes an atmospheric air temperature (detected by a sensor), Pb denotes a compressor downstream pressure (output from the intercooler reversal model RM42), Ga denotes a fresh air amount (detected by a sensor), ηc a Efficiency of the compressor 22 denotes Ca (for example, obtained based on a map), Ca denotes a specific heat of the air (a constant), and Ka denotes a ratio of the specific heat of the air (a con stante).

Thus, the intake inversion models RM4a and RM4b receive an input of a boost pressure (target boost pressure TP or actual boost pressure AP) downstream of the throttle valve 24 through the models RM41, RM42 and RM43 and provide values obtained by reflecting the characteristics of the engine intake system from the actual boost pressure measurement position (upstream of the throttle valve 24 ) to the turbocharger 50 (Compressor 22 ) are created for input. The compressor capacity Ltc according to the drive amount of the compressor 22 (Target driving amount QC or actual driving amount NC) is output from each of the intake inversion models RM4a and RM4b (see FIG 4 ).

Next, the engine model M3 and the engine reversing model RM3 ( 3 ) in detail with reference to 6 explained.

As in 6 is shown, has a driving amount of the assisting motor 52 (a backup drive amount NA) a time lag with respect to a power instruction value (instruction compressor power) based on the response characteristics of the assist motor 52 on. Therefore, the supercharging pressure control in the embodiment performs correction taking into account the influence of such deceleration by the engine model M3 and the engine reversing model RM3.

als Modell dargestellt. Damit wird ein tatsächlicheres Modell unter Berücksichtigung der Ansprechcharakteristiken (des Einflusses einer Verzögerung) des Unterstützungsmotors 52 mit der Software aufgebaut und sollte die vorstehend erwähnte Ladedrucksteuerung durch diese Programme genauer durchgeführt werden. Es ist anzumerken, dass in dem Ausführungsbeispiel der Halteblock B1 (3) für die Eingabe des Motormodells M3 vorgesehen ist. Daher werden bei dem Motormodell M3 und dem Motorumkehrmodell RM3 Berechnungen diskret (beispielsweise alle 32 ms) vorgenommen. Zusätzlich kann die Ordnung der Verzögerung mit Bezug auf die Übertragungsfunktion TF frei eingerichtet werden. Jedoch vergrößert sich die Berechnungsgenauigkeit, wenn die Ordnung der Verzögerung sich vergrößert, und vergrößert sich ebenso die Berechnungsbelastung. Daher ist es vorzuziehen, dass die Ordnung normalerweise eine sekundäre Verzögerung oder so Ähnliches ist.More specifically, such a delay (a delay amount) can be appropriately corrected by using a transfer function in consideration of a delay element. For example, as in 6 is shown, the motor model M3 and the motor reversing model RM3 as the reversal model each as a transfer function TF of a secondary deceleration system, such as

presented as a model. Thus, a more actual model becomes taking into consideration the response characteristics (the influence of deceleration) of the assist motor 52 built with the software and the above-mentioned boost pressure control should be performed by these programs more accurate. It should be noted that in the embodiment, the holding block B1 (FIG. 3 ) is provided for the input of the motor model M3. Therefore, in the engine model M3 and the engine reversing model RM3, calculations are made discretely (for example every 32 ms). In addition, the order of the delay with respect to the transfer function TF can be set freely. However, the calculation accuracy increases as the order of deceleration increases, and so does the computational load. Therefore, it is preferable that the order is normally a secondary delay or the like.

Next, referring to 7 jointly explains the process order of the boost pressure control in the wastegate control of the embodiment. A series of processes in 7 is executed sequentially for each predetermined crank angle or in a predetermined time cycle (for example, a cycle of 32 ms) by executing programs stored in the ROM with the ECU (in particular, the CPU). Namely, the series of these processes is executed in a virtual engine control system constructed in software (ROM). In addition, values of various parameters used in the series of processes are stored at an appropriate timing in the storage device such as the RAM or the EEPROM installed in the ECU, and are updated as needed.

As in 7 1, in order to execute the series of processes, first, in step S11, a target boost pressure TP is calculated on the basis of the torque demand. Next, in step S12, a target driving amount QC of the compressor 22 calculated based on this target boost pressure TP by the intake inversion model RM4a. The calculation of the target boost pressure TP is made in a section that is in 3 not shown. The portion (the target boost pressure calculating portion) has a clear relation to the construction in FIG 3 and therefore the drawing is omitted.

Next, in step S13, an actual boost pressure AP is obtained as an actual measured value. More specifically, the actual boost pressure AP is calculated on the basis of a sensor output of a pressure sensor, the current down the throttle valve 24 is located. An actual drive amount NC of the compressor 22 is calculated on the basis of the actual boost pressure AP. It should be noted that the calculation of the actual boost pressure AP is made in a section that is in 3 not shown. The section (the boost pressure calculating device) has a clear relation to the construction in FIG 3 and therefore the drawing is omitted.

Next, in step S15, a assist driving amount NA is calculated by the motor model M3. As described above, the assist driving amount NA is obtained as a value obtained by reproducing the response characteristics of the assisting motor 52 to the instruction compressor power (the previous value) is obtained.

Next, in step S16, a calculating section C1 calculates an exhaust gas driving amount component NCex as a difference between the actual driving amount NC and the assist driving amount NA (NCex = NC-NA). Further, in step S17, a calculating section C2 calculates a assist power QN as a difference between the target driving amount QC and the exhaust gas driving amount component NCex (QN = QC-NCex). Further, the calculating section C2 calculates an instruction compressor output by reproducing the response characteristics of the assist motor 52 to the assist power QN in the engine reversing model RM3. In addition, in step S18, the boost pressure to the target boost pressure TP is controlled by controlling the drive of the assist motor 52 controlled with this instruction compressor performance.

The Series of processes is completed by the process of step S18. However, by repeatedly executing the processes, the control becomes of the boost pressure is successively carried out in at least one period, in the execution is required.

• (1) Eine Ladedrucksteuerung wird in einem Verbrennungsmotorsteuersystem einschließlich eines Turboladers 50 zum Durchführen einer Aufladung in einem Verbrennungsmotoreinlasssystem durch einen Verdichter 22, der sich gemeinsam mit einer Turbine 31, die in einem Verbrennungsmotorabgassystem vorgesehen ist, auf der Grundlage des Antriebs der Turbine 31 durch eine Abgasströmung bewegt, und eines Unterstützungsmotors 52 (eine Ladedruckveränderungsvorrichtung) verwendet, der durch Leistung angetrieben wird, die eine andere als diejenige der Abgasströmung ist (von einer Batterie zugeführte Leistung), um einen Ladedruck zu verändern. Die Ladedrucksteuerung umfasst ein Programm (eine Ladedruckmessvorrichtung, Schritt S13) zum Messen eines Ist-Ladedrucks AP als Einlassdruck an einer vorbestimmten Position (stromabwärts des Drosselventils 24) des Verbrennungsmotoreinlasssystems, ein Programm (Ist-Ladegrößenberechnungsvorrichtung, Einlassumkehrmodell RM4b) zum Berechnen einer Ist-Ladegröße (Ist-Antriebsbetrag NC) auf der Grundlage des Antriebs des Verdichters 22 auf der Grundlage des Ist-Ladedrucks AP, der durch dieses Programm gemessen wird, ein Programm (Ladedruckänderungsbetragsgewinnungsvorrichtung, Motormodell M3) zum Erhalten eines Ladedruckänderungsbetrags (Unterstützungsantriebsbetrags NA) auf der Grundlage des Antriebs des Unterstützungsmotors 52 auf der Grundlage einer Anweisungsverdichterleistung und ein Programm (Abgasantriebsbetragsberechnungsvorrichtung, Berechnungsabschnitt C1) zum Berechnen einer Abgasantriebsbetragskomponente NCex auf der Grundlage des Ist-Antriebsbetrags NC und des Unterstützungsantriebsbetrags NA. Als Folge können auch in einem Fall, dass die Ladedrucksteuerung an einem komplizierten Auslasssystem montiert wird, Berechnungsbelastungen oder Berechnungsfehler bei der Ladedrucksteuerung verringert werden.
• (2) Das Einlassumkehrmodell RM4b empfängt eine Eingabe eines Ist-Ladedrucks AP und weist Programme (Ist- Ladedruckabgabeabschnitt, Drosselumkehrmodell RM41 und Zwischenkühlerumkehrmodell RM42) zum Abgeben eines Werts, der durch eine Wiedergabe der Charakteristiken des Verbrennungsmotoreinlasssystems von der Ist-Ladedruckmessposition (stromabwärts des Drosselventils 24) zu dem Turbolader 50 (Verdichter 22) erstellt wird, zu dieser Eingabe auf. Damit ist es möglich, einen Ladedruck (Verdichterstromabwärtsdruck Pb) in dem Turbolader 50, schließlich einen Antriebsbetrag (Ist-Antriebsbetrag NC) des Verdichters 22 höchstgenau zu erhalten.
• (3) Das Einlassumkehrmodell RM4b ist so aufgebaut, dass es einen Abschnitt, der durch Abbilden eines Modells des Verbrennungsmotoreinlasssystems aufgebaut ist, nämlich den Einlasssystemmodellabschnitt aufweist. Daher ist es einfacher, eine derartige Konstruktion zu verwirklichen.
• (4) Das Einlassumkehrmodell RM4b hat diejenige Konstruktion, bei der Komponenten (Drosselventil 24, Zwischenkühler 23 und Verdichter 22) des Verbrennungsmotoreinlasssystems pro Komponenteneinheit als Modul dargestellt sind. Jedes Modul (Drosselumkehrmodell RM41, Zwischenkühlerumkehrmodell RM42 und Verdichterumkehrmodell RM43) gibt einen Wert, der durch Wiedergeben der Charakteristiken jeder Komponente erstellt wird, an jede Eingabe ab. Eingaben/Abgaben zwischen den Modulen sind gemäß der Auslegung der Komponenten des Einlasssystems verbunden. Damit ist es einfacher, Programme zu erzeugen, und wird die Annehmlichkeit im Hinblick auf die Handhabung der Programme verbessert.
• (5) Das Einlassumkehrmodell RM4b ist so aufgebaut, dass jede Komponente in dem Einlasssystem als Modell abgebildet wird. Daher ist es einfacher, eine solche Konstruktion zu verwirklichen.
• (6) Das Einlassumkehrmodell RM4b wird durch ein charakteristisches Modell (Zwischenkühlerumkehrmodell RM42), das eine Beziehung zwischen einer Vielzahl von Parametern mit Bezug auf vorbestimmte Charakteristiken zeigt, und ein mathematisches Modell abgebildet, bei dem ein gewisses Naturphänomen mathematisch beschrieben wird (Drosselumkehrmodell RM41 und Verdichterumkehrmodell RM43). Das bewirkt eine hervorragende Einfachheit der Verwirklichung und Leistungsfähigkeit der Konstruktion (Berechnungsgenauigkeit und dergleichen).
• (7) Das Motormodell M3 ist ein Motormodellabschnitt, der durch Abbilden des Unterstützungsmotors 52 (des Elektromotors) als Modell vorgenommen wird, bei dem die Charakteristiken des Unterstützungsmotors 52 auf einen Anweisungswert (Anweisungsverdichterleistung) der Zufuhrleistung zu dem Unterstützungsmotor 52 wiedergegeben werden und der wiedergegebene Wert als Unterstützungsbetrag NA erhalten wird. Als Folge können die Vereinfachung der Konstruktion und die Verringerung der Berechnungsbelastungen erzielt werden.
• (8) Der vorausgehende Wert (Wert, der zur vorausgehenden Zeit berechnet wird) wird als Anweisungsverdichterleistung verwendet, der zur Berechnung des Unterstützungsantriebsbetrags NA verwendet wird. Das ermöglicht eine bessere Steuerbarkeit.
• (9) Das Motormodell M3 wird durch Abbilden eines Abschnitts als Modell erzeugt, der sich auf die Ansprechcharakteristiken des Unterstützungsmotors 52 (des Elektromotors) bezieht. Das gestattet die Ladedrucksteuerung mit einer hohen Genauigkeit.
• (10) Das Motormodell M3 wird mit einer Übertragungsfunktion als Modell abgebildet, die die entsprechende Beziehung zwischen der Eingabe und der Ausgabe zeigt. Das gestattet eine hervorragende Konstruktion im Hinblick auf die Einfachheit der Verwirklichung und der Leistungsfähigkeit (der Berechnungsgenauigkeit und dergleichen).
• (11) Das Motormodell ist mit einem Programm (einer Sollantriebsmotorberechnungsvorrichtung und einem Einlassumkehrmodell RM4) zum Berechnen eines Soll-Antriebsbetrags QC des Verdichters 22 auf der Grundlage eines Soll-Ladedrucks TP als Steuersollwert, der sich auf die Ladedrucksteuerung bezieht, und einem Programm (Leistungsberechnungsvorrichtung, Berechnungsabschnitt C2 und Motorumkehrmodell RM3) zum Berechnen einer Leistung (einer Unterstützungsleistung QN) des Unterstützungsmotors 52, schließlich einer Anweisungsverdichterleistung, die zum Steuern des Ladedrucks auf den Soll-Ladedruck TP erforderlich ist, auf der Grundlage des Soll-Antriebsbetrags QC und einer Abgasantriebsbetragskomponente NCex aufgebaut. Das gestattet eine Verbesserung der Steuerbarkeit bei der Ladedrucksteuerung.
• (12) Das Einlassumkehrmodell RM4a ist aufgebaut, um als Eingabe einen Soll-Ladedruck TP als Soll-Druckwert an einer Ist-Ladedruckmessposition (stromabwärts des Drosselventils 24) zu empfangen und weist ein Programm (einen Soll-Ladedruckabgabeabschnitt, ein Drosselumkehrmodell RM41 und ein Zwischenkühlerumkehrmodell RM42) zum Abgeben eines Werts auf, der durch Wiedergeben der Charakteristiken des Verbrennungsmotoreinlasssystems von dem Ist-Ladedruckmessabschnitt zu dem Turbolader 50 auf den eingegebenen Soll-Ladedruck TP erstellt wird. Diese Konstruktion gestattet, dass der Ladedruck in dem Turbolader 50, schließlich ein Soll-Antriebsbetrag QC des Verdichters gemäß der Ist-Ladedruckmessposition bestimmt wird. Als Folge kann der Ladedruck einfacher und genauer auf der Grundlage des Ist-Ladedrucks AP und des Soll-Ladedrucks TP gesteuert werden.
• (13) Das Einlassumkehrmodell RM4a ist durch Abbilden des Verbrennungsmotoreinlasssystems als Modell aufgebaut, nämlich einschließlich des Einlasssystemmodellabschnitts. Als Folge ist es einfach, eine solche Konstruktion zu verwirklichen.
• (14) Ferner haben in dem Ausführungsbeispiel das Einlassumkehrmodell RM4b (Ist-Ladedruckabgabeabschnitt) und das Einlassumkehrmodell RM4a (Soll-Ladedruckabgabeabschnitt) die gleiche Konstruktion. Daher wird eine Vereinfachung der Konstruktion erzielt und wird ebenso die Berechnungsgenauigkeit verbessert.
• (15) Das Motorumkehrmodell RM3 ist so aufgebaut, dass es einen Abschnitt, der durch Abbilden des Unterstützungsmotors 52 (des Elektromotors) als Modell ausgebildet ist, nämlich einen Motormodellabschnitt aufweist. Daher ist es möglich, den Leistungswert (den elektrischen Wert) mit hoher Genauigkeit zu erhalten.
• (16) Das Motorumkehrmodell RM3 wird durch Abbilden eines Abschnitts als Modell erzeugt, der sich auf die Ansprechcharakteristiken des Unterstützungsmotors 52 (des Elektromotors) bezieht. Das gestattet die Ladedrucksteuerung mit einer hohen Genauigkeit.
• (17) Das Motorumkehrmodell RM3 wird mit einer Übertragungsfunktion als Modell abgebildet, die die entsprechende Beziehung zwischen der Eingabe und der Ausgabe zeigt. Das gestattet die Konstruktion, die im Hinblick auf die Einfachheit der Verwirklichung und der Leistungsfähigkeit (der Berechnungsgenauigkeit und dergleichen) hervorragend ist.
• (18) Eine elektrische Bauart des Unterstützungsmotors 52, der in dem Turbolader 50 montiert ist, um den Antrieb des Turboladers 50 zu unterstützen, wird als Vorrichtung (Ladedruckveränderungsvorrichtung) angenommen, die durch eine Leistung angetrieben wird, die eine andere als diejenige der Abgasströmung ist, um einen Ladedruck zu verändern. Mit dieser Konstruktion ist es möglich, eine höchst genaue Verbrennungsmotorsteuerung praktisch durchzuführen.
• (19) Als Steuergegenstand wird eine Vorrichtung verwendet, die ein Verbrennungsmotorsystem hat, das mit einer EGR-Vorrichtung 40, einem Turbolader 50 mit einem variablen Düsenmechanismus (einem Mechanismus mit variabler Geometrie), einem DPF 32 (Filter für eine PM-Entfernung) und einem NOx-Katalysator 33 versehen ist. Diese Vorrichtung ermöglicht eine hohe Verbrennungsmotorleistungsfähigkeit gemäß jeder Aufgabe dieser Vorrichtungen und ebenso eine Verringerung der Berechnungsbelastungen oder der Berechnungsfehler beim Steuern des Ladedrucks. Beispielsweise ist es nicht erforderlich, ein Kennfeld oder Ähnliches zum Definieren eines Adaptionswerts von Druckcharakteristiken für jede Bedingung des variablen Düsenmechanismus (beispielsweise eine Öffnung der Düse) zu verwenden, und es ist möglich, den Ladedruck durch den variablen Düsenmechanismus variabel zu steuern.

According to the embodiment described in detail, the excellent advantages are obtained as follows.

• (1) A boost pressure control becomes in an engine control system including a turbocharger 50 for performing a charge in an engine intake system by a compressor 22 that works together with a turbine 31 , which is provided in an engine exhaust system, based on the drive of the turbine 31 moved by an exhaust gas flow, and a assisting motor 52 (a boost pressure changing device) which is driven by power other than that of the exhaust gas flow (power supplied from a battery) to change a boost pressure. The wastegate includes a program (a supercharging pressure measuring device, step S13) for measuring an actual supercharging pressure AP as an intake pressure at a predetermined position (downstream of the throttle valve 24 ) of the engine intake system, a program (actual charge amount calculation device, intake inversion model RM4b) for calculating an actual charge amount (actual drive amount NC) based on the drive of the compressor 22 on the basis of the actual boost pressure AP measured by this program, a program (boost pressure change amount obtaining device, engine model M3) for obtaining a boost pressure change amount (assist driving amount NA) based on the drive of the assisting motor 52 on the basis of an instruction compressor output and a program (exhaust-gas-amount-calculating device, calculating section C1) for calculating an exhaust-gas-driving-amount component NCex on the basis of the actual driving amount NC and the assist driving amount NA. As a result, even in a case that the wastegate control is mounted on a complicated exhaust system, calculation loads or calculation errors in the wastegate control can be reduced.
• (2) The intake inversion model RM4b receives an input of an actual boost pressure AP and has programs (actual boost pressure output portion, throttle inversion model RM41 and intercooler reversal model RM42) for outputting a value represented by a representation of the characteristics of the engine intake system from the actual boost pressure measurement position (downstream of the throttle valve 24 ) to the turbocharger 50 (Compressor 22 ) is created for this input. Thus, it is possible to have a supercharging pressure (compressor downstream pressure Pb) in the turbocharger 50 , Finally, an amount of drive (actual drive amount NC) of the compressor 22 to get highly accurate.
• (3) The intake inversion model RM4b is configured to have a portion constructed by mapping a model of the engine intake system, namely, the intake system model portion. Therefore, it is easier to realize such a construction.
• (4) The intake inversion model RM4b has the construction in which components (throttle valve 24 , Intercooler 23 and compressors 22 ) of the engine intake system per component unit are shown as a module. Each module (throttle reversal model RM41, intercooler reversal model RM42, and compressor reversal model RM43) outputs a value, which is generated by reproducing the characteristics of each component, to each input. Inputs / deliveries between the modules are according to the Design of the components of the intake system connected. This makes it easier to create programs and improves convenience in handling the programs.
• (5) The intake inversion model RM4b is constructed such that each component in the intake system is mapped as a model. Therefore, it is easier to realize such a construction.
• (6) The intake inversion model RM4b is represented by a characteristic model (intercooler reversal model RM42) showing a relationship between a plurality of parameters with respect to predetermined characteristics and a mathematical model in which a certain natural phenomenon is mathematically described (throttle inversion model RM41 and compressor inversion model RM43). This brings about excellent simplicity of realization and performance of the construction (calculation accuracy and the like).
• (7) The engine model M3 is a motor model section formed by mapping the assist motor 52 (the electric motor) is made as a model in which the characteristics of the assisting motor 52 to an instruction value (instruction compressor power) of the supply power to the assist motor 52 and the reproduced value is obtained as a support amount NA. As a result, the simplification of the construction and the reduction of the computational burden can be achieved.
• (8) The previous value (value calculated at the previous time) is used as the instruction compressor output used for calculating the assist driving amount NA. This allows better controllability.
• (9) The motor model M3 is produced by mapping a section as a model based on the response characteristics of the assist motor 52 (of the electric motor) refers. This allows the wastegate control with high accuracy.
• (10) The motor model M3 is modeled with a transfer function showing the corresponding relationship between the input and the output. This allows an excellent construction in view of the simplicity of the realization and the performance (the calculation accuracy and the like).
• (11) The engine model is provided with a program (a target drive motor calculation device and an intake inversion model RM4) for calculating a target drive amount QC of the compressor 22 on the basis of a target supercharging pressure TP as a control target value related to the supercharging pressure control and a program (power calculating device, calculating section C2 and motor reversing model RM3) for calculating a power (assist power QN) of the assisting motor 52 , finally, an instruction compressor output required to control the boost pressure to the target boost pressure TP, based on the target drive amount QC and an exhaust gas drive amount component NCex. This allows an improvement in controllability in the wastegate control.
• (12) The intake inversion model RM4a is configured to input a target boost pressure TP as a target pressure value at an actual boost pressure measurement position (downstream of the throttle valve 24 ) and includes a program (a target boost pressure output section, a throttle reverse model RM41 and an intercooler reversal model RM42) for outputting a value obtained by reproducing the characteristics of the engine intake system from the actual boost pressure measuring section to the turbocharger 50 is created on the entered target boost pressure TP. This design allows the boost pressure in the turbocharger 50 , Finally, a target driving amount QC of the compressor according to the actual boost pressure measuring position is determined. As a result, the supercharging pressure can be controlled more easily and accurately based on the actual supercharging pressure AP and the target supercharging pressure TP.
• (13) The intake inversion model RM4a is constructed by mapping the engine intake system as a model, namely, including the intake system model section. As a result, it is easy to realize such a construction.
• (14) Further, in the embodiment, the intake inversion model RM4b (actual charge pressure discharge portion) and the intake inversion model RM4a (target charge pressure discharge portion) have the same construction. Therefore, a simplification of the design is achieved and also the calculation accuracy is improved.
• (15) The motor reversing model RM3 is configured to have a portion formed by imaging the assist motor 52 (the electric motor) is designed as a model, namely having a motor model section. Therefore, it is possible to obtain the power value (the electric value) with high accuracy.
• (16) The motor reversing model RM3 is modeled by mapping a section based on the response characteristics of the assist motor 52 (of the electric motor) refers. This allows the wastegate control with high accuracy.
• (17) The motor reversing model RM3 is modeled with a transfer function showing the corresponding relation between the input and the output. This allows the construction, in view of the simplicity of the realization and the performance (the calculation accuracy and the like) is excellent.
• (18) An electric type of the assisting motor 52 in the turbocharger 50 is mounted to the drive of the turbocharger 50 to assist is assumed to be a device (boost pressure varying device) driven by a power other than that of the exhaust gas flow to change a boost pressure. With this construction, it is possible to practically perform a highly accurate engine control.
• (19) As a control object, a device having an engine system equipped with an EGR device is used 40 , a turbocharger 50 with a variable nozzle mechanism (a variable geometry mechanism), a DPF 32 (Filter for a PM removal) and a NOx catalyst 33 is provided. This device enables high engine performance in accordance with each object of these devices, as well as a reduction in the computational load or the calculation error in controlling the boost pressure. For example, it is not necessary to use a map or the like for defining an adaptation value of pressure characteristics for each condition of the variable nozzle mechanism (for example, an opening of the nozzle), and it is possible to variably control the supercharging pressure by the variable nozzle mechanism.

The The present invention is not limited to the description of the above mentioned embodiment limited and can be executed as follows become.

The embodiment assumes as a control object a device having an engine exhaust system provided with an EGR device 40 , a turbocharger 50 with a variable nozzle mechanism, a DPF 32 and a NOx catalyst as an example, but a freely selectable system may be adopted as a control object.

An auxiliary compressor, upstream or downstream of the compressor 22 is arranged to charge the turbocharger 50 Can backup instead of the backup motor 52 may be used as a device (boost pressure varying device) that is driven by a power other than that of the exhaust gas flow to change the boost pressure. 8th shows an example of the application of such an auxiliary compressor in place of the assisting motor 52 , In the in 8th shown construction is an electric compressor 221 as an auxiliary compressor upstream of the compressor 22 arranged and is also a compressor drive motor 222 to power the electric compressor 221 arranged. It should be noted that the electric compressor 221 downstream of the compressor 22 (or on both sides upstream and downstream of the compressor 22 ) can be arranged. Here is an example of the auxiliary compressor instead of the backup motor 52 shown, but both the support engine 52 as well as the auxiliary compressor can be provided. Also, such a construction can produce the same effect or the effect almost equivalent to the effect in the above-mentioned point (FIG. 18 ). Further, the boost pressure varying device is not limited to the assist motor or the auxiliary compressor, but may take any device that can be driven by a power other than that of the exhaust flow to change the boost pressure.

In the embodiment the actual boost pressure AP becomes based on an output value of the pressure sensor measured, but not limited to, for example based on a fresh air amount or an intake air temperature can be measured.

In addition, a measurement position of the actual boost pressure AP may also be set to any position of an engine intake system that is not on the downstream side of the throttle valve 24 is limited.

In the embodiment will be the motor reversing model RM3 and the motor model M3 with a transfer function pictured as a model, but they can come with a characteristic Model, a mathematical model or the like as a model become.

The Inlet reversal models RM4a and RM4b can be used in any type according to their Application or similar be modeled as a model. In other words, if only the intake reversal models RM4a and RM4b by showing the engine intake system be modeled, the same effect or the effect which are almost equivalent to the effects of the mentioned above Points (2), (3), (12) and (13) are. In addition, by mapping of these as a model with at least one of the transfer function, the characteristic model and the mathematical model the same effect or effect can be obtained, which is almost equivalent to the effect of the aforementioned item (6).

The mapping as a model is not limited to the program construction, which in 3 4, but elements formed by dividing the components of the engine intake system into multiple components (segment formation) may be modeled. For example, the inlet pipe 12 or the wave 51 be modeled according to the devices as a model, which in JP-2006-22763A are described. Further, the EGR device or the like may be modeled as needed. On the other hand, unnecessary models may be omitted depending on their application. For example, in the case that the highly accurate calculation is not required, the engine reversing model RM3 may be omitted.

If In other words, the embodiment from a device for measuring an actual boost pressure AP as intake pressure at a predetermined position of the engine intake system, a device for calculating an actual charge size by the drive of the compressor on the basis of the actual boost pressure AP, a device for obtaining a boost pressure change amount by the drive of the wastegate and a Apparatus for calculating an exhaust gas drive amount component of Compressor based on the actual charge size and the charge pressure change amount constructed is, the same effect or effect can be obtained which is almost equivalent to the effect of the above-mentioned point (1), and at least the first task is solved.

The embodiment uses a variety of software (programs), but can use hardware, such as e.g. an exclusive one Use circuit to accomplish similar function.

The embodiment describes the case where the invention relates to a diesel engine is applied as an example, but it can be fundamental to one spark ignition Petrol internal combustion engine (especially a direct injection internal combustion engine) be applied.

While only the selected ones exemplary embodiments For the purpose of illustrating the present invention, it is known to those skilled in the art From this disclosure, it is obvious that various changes and modifications thereto without departing from the scope can be made of the invention defined in the appended claims is. Furthermore, the foregoing description is exemplary embodiments according to the present For the sake of illustration only and not for the purpose of limiting the invention Invention provided by the appended claims and their equivalents is defined.

Thus, the wastegate control uses as a control subject a system that uses a turbocharger 50 is provided, the charging in an internal combustion engine intake system by a compressor 22 and a support motor 52 performs a drive of the turbocharger 50 to support. The wastegate controller has a program for measuring an actual boost pressure as the intake pressure downstream of the throttle valve 24 in the engine intake system, a program (intake inversion model RM4b) for calculating an actual charge amount (actual driving amount NC) by the drive of the compressor 22 as the basis of the actual boost pressure, a program (engine model M3) for calculating (boosting) a charge amount change amount (assist drive amount NA) by the drive of the assist motor based on an instruction compressor output and a program (calculation section C1) for calculating an exhaust gas drive amount component NCex on the basis of the actual driving amount NC and the assist driving amount NA.

Claims (14)

Boost pressure control used in an engine control system that includes a turbocharger ( 50 ) for performing charging in an engine intake system by a compressor ( 22 ) in cooperation with a turbine ( 31 ) provided in an engine exhaust system based on a drive of the turbine ( 31 ) by an exhaust gas flow and a waste pressure changing device ( 52 ), which is driven by a power other than that of the exhaust gas flow to change a boost pressure, wherein the wastegate control an exhaust gas drive amount component corresponding to an amount of drive by the exhaust gas flow from a driving amount of the compressor ( 22 ) for controlling the supercharging pressure of the internal combustion engine based on the exhaust gas drive amount component, comprising: a supercharging pressure measuring device for measuring an actual supercharging pressure (AP) as intake pressure at a predetermined position of the engine intake system; an actual charging amount calculating device for calculating an actual charging amount by driving the compressor ( 22 ) based on the actual boost pressure (AP), which gemes by the boost pressure measuring device gemes will be; a boost pressure change amount obtaining device for obtaining a boost pressure change amount based on driving of the waste pressure changing device (10) 52 ); and an exhaust gas drive amount calculating device for calculating an exhaust gas drive amount component of the compressor ( 22 ) based on the actual load size through the compressor ( 22 ) calculated by the actual boost amount calculating device and the boost pressure change amount obtained by the boost pressure change amount obtaining device. The boost pressure controller according to claim 1, wherein: the actual charge amount calculating device has an actual boost pressure output section that receives an input of the actual boost pressure (AP) to output a value obtained by repeating characteristics of the engine intake system from an actual boost pressure measurement position of the boost pressure measurement device Turbocharger ( 50 ) is created on the entered actual boost pressure (AP). Boost pressure control according to claim 2, wherein: of the Actual boost pressure output section per component unit of the engine intake system is mapped as a module; with each module giving a value, by reproducing characteristics of each component the input is created; and with an input / output between the modules according to a design of the components in the engine intake system are connected. Boost pressure control according to one of claims 1 to 3, wherein: the actual load size calculation device an intake system model section (M4) included in the engine intake system is shown as a model. Boost pressure control according to claim 4, wherein: of the An intake system model section (M4) for each component of the engine intake system is shown as a model. Boost pressure control according to claim 4 or 5, wherein: the Intake system model (M4) by at least one of a characteristic Model that has a relationship between a variety of parameters with reference to predetermined characteristics, a transfer function, the one corresponding relationship between the input and the output shows, and a mathematical model that mathematically predetermines a natural phenomenon describes as a model is mapped. Boost pressure control according to one of claims 1 to 6, wherein: the waste pressure changing device ( 52 ) by an electric motor ( 52 ) is driven; wherein the boost pressure change amount obtaining means includes a motor model portion (M3) modeled on the electric motor and reproduces characteristics of the electric motor to an instruction value of supply of power to the electric motor by the motor model portion (M3) to obtain the reproduced value as the boost pressure change amount. The boost pressure controller according to claim 7, wherein: the motor model portion (M3) is a portion formed by imaging a portion as a model that is responsive to response characteristics of the electric motor (15); 52 ). Boost pressure control according to claim 7 or 8, wherein: of the Motor model section (M3) by at least one of a characteristic Model that has a relationship between a variety of parameters with reference to predetermined characteristics, a transfer function, the one corresponding relationship between the input and the output shows, and a mathematical model that mathematically predetermines Natural phenomenon describes as a model is mapped. A boost pressure controller according to any one of claims 1 to 9, further comprising: a target driving amount calculating device for calculating a target driving amount of the compressor ( 22 ) based on a target boost pressure (TP) as a control target value related to the boost pressure control; and a power calculating device for calculating power of the waste pressure changing device ( 52 ) required to control the boost pressure to the target boost pressure, based on a target drive amount of the compressor (FIG. 22 ) calculated by the target driving amount calculating device and an exhaust gas driving amount component of the compressor ( 22 ) calculated by the exhaust gas drive amount calculating device. The boost pressure controller according to claim 10, wherein: the target driving amount calculating device has a target boost pressure output section that includes inputting the target boost pressure (TP) as a target pressure value at an actual boost pressure measuring position of the boost pressure measuring device ( 52 ) to output a value obtained by reflecting characteristics of the engine intake system from the actual boost pressure measurement position to the turbocharger (FIG. 50 ) is created on the entered target boost pressure. Boost pressure control according to claim 10 or 11, wherein: the Target drive amount calculating device, an intake system model section (M4) used in the engine intake system as a model is shown. A boost pressure controller according to any one of claims 1 to 12, wherein: the boost pressure varying device includes at least one of a backup electric motor attached to the turbocharger ( 50 ) is mounted to the drive of the turbocharger ( 50 ) and an auxiliary compressor ( 221 ) located upstream or downstream of the compressor ( 22 ) is to charge the turbocharger ( 50 ) to support. Boost pressure control according to one of claims 1 to 13, wherein: the internal combustion engine exhaust system with at least one of an EGR device ( 40 ), a turbocharger ( 50 ) with a variable geometry mechanism, a PM removal filter ( 32 ) and a NOx catalyst ( 33 ) is provided.