Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
  • F02B37/22—Control of the pumps by varying cross-section of exhaust passages or air passages, e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
  • F02B37/24—Control of the pumps by using pumps or turbines with adjustable guide vanes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• a system and method for controlling a turbo supercharger for an internal combustion engine is disclosed.
• the present invention relates generally to the technique of managing an internal combustion engine comprising a set of sensors and actuators, said engine comprising a turbocharger composed of a turbine and a compressor in order to increase the amount of air admitted into the engine cylinders.
• ECU electronice control unit
• the turbocharger comprises a turbine placed at the outlet of the exhaust manifold and driven by the exhaust gas.
• the power taken by the exhaust turbine can be advantageously modulated by installing blades of variable orientation at the inlet of the turbine. This is called a variable geometry turbine.
• the power provided by the compressor can in turn be modulated by arranging vanes of variable orientation at the inlet or the outlet of the compressor. We speak of compressor with variable geometry.
• the compressor is mounted on the same axis as the turbine and compresses the air entering the intake manifold.
• a heat exchanger can be placed between the compressor and the intake manifold to cool the air at the outlet of the compressor.
• Actuators are provided for controlling the opening and closing of the set of vanes with variable orientation, which respectively equip the turbine and the compressor.
• the control signals of these actuators are provided by the electronic control unit, so as to slave the pressure in the intake manifold.
• the value set point of the pressure in the manifold is calculated by the electronic control unit.
• the actual value of the pressure is measured by means of a pressure sensor placed in the intake manifold.
• the reference value of the boost pressure can be mapped according to the rotational speed of the engine and the fuel flow admitted into the engine. This pressure reference value can then be corrected according to a certain number of environmental variables, such as, for example, the atmospheric pressure, the temperature of the air entering the compressor, etc. For engine rotation and fuel flow, it is possible to identify the amount of air required for optimal combustion in the engine. This amount of air can then be translated into a booster pressure setpoint.
• the turbocharger it is necessary to respect the characteristics of the turbocharger, among which, in particular, what is called the field of the compressor. Indeed, for a given geometry of the compressor, it is possible to determine the compression ratio as a function of the air flow rate in the compressor, the compression ratio being defined as the ratio of the pressure of the air leaving the compressor on the compressor. the pressure of the air entering the compressor.
• the Compressor rotation speed must not exceed a limit value, otherwise we enter what is called the overspeed zone for which the compressor may be destroyed. In the same way, it is important to avoid a so-called "pumping" zone, in which there is an inversion of the air flow through the compressor for the low air flows, such a pumping phenomenon also causing the destruction of the compressor.
• the operating zone of the compressor must therefore ultimately be between the overspeed limit and the pumping limit. All operating points of the compressor must thus be in the compressor field which represents the acceptable values for the operation of the compressor.
• variable geometry compressor makes it possible to obtain different compressor fields and thus to choose the efficiency and the speed of rotation of the compressor by controlling the geometry of the compressor. This results in a larger operating area, since the pumping and overspeed limits depend on the geometry of the compressor.
• French patent application 2,833,303 (DAIMLER CHRYSLER) describes a turbocharger control system which comprises a sensor detecting the pumping limit of the compressor by detecting the vibrations of the compressor. The regulation is then able to act on the position of the adjustable tilt blades of the compressor, so as to avoid operation of the compressor in the pumping zone.
• the patent application WO 2004/038229 also has the object of preventing entry into the pumping zone of a compressor.
• the detection of the pumping limit is done by a measurement of air flow velocity in the boundary layer of a compressor output channel.
• the servocontrol described in this document is done on the speed of air flow in the compressor.
• the present invention aims to optimize the efficiency of the compressor and to avoid exceeding the limits of pumping and overspeed by increasing the turbocharger management flexibility.
• the subject of the invention is also a control system, in which a regulation receives a corrected setpoint value as a function of various parameters.
• the invention also relates to a control system, in which the regulation is simplified during the stabilized operating phases of the engine.
• control system of a turbocharger for a motor vehicle internal combustion engine of the type comprising a variable geometry turbine and a variable geometry compressor comprises a first device for regulating the supercharging pressure. able to act on a control of the geometry of the turbine.
• the system further comprises a second device for regulating the geometry of the variable geometry compressor capable of acting on a control of the geometry of the compressor.
• the system preferably comprises a memory for memorizing a mapping of the values of the geometry of the compressor as a function of the rotational speed of the engine and the flow of fuel injected into the engine. Means may be provided to introduce one or more corrections to the set value of the geometry of the compressor, according to different parameters.
• a sensor is provided for measuring the flow rate of air passing through the compressor and the system comprises means for correcting the set value of the geometry of the compressor as a function of the measured airflow. Such a correction makes it possible to vary the compression ratio, the speed of rotation and the efficiency of the compressor as a function of the flow of air passing through the compressor.
• a sensor is provided for measuring the temperature of the air upstream of the compressor and the system comprises means for correcting the set value of the geometry of the compressor as a function of the measured temperature. Such a correction makes it possible to vary the compression ratio, the air flow rate passing through the compressor, the rotational speed and the efficiency of the compressor as a function of the temperature prevailing in the compressor.
• a sensor is provided for measuring the rotational speed of the compressor and the system comprises a means for correcting the value of the geometry of the compressor as a function of the rotational speed measured. Such a correction makes it possible to vary the compression ratio, the flow rate of air passing through the compressor and the efficiency of the compressor depending on the rotational speed of the compressor.
• a sensor is provided for measuring the air pressure upstream of the compressor and the system includes means for correcting the set value of the compressor geometry as a function of the air pressure. measured upstream. Such a correction makes it possible to vary the compression ratio, the flow rate of air passing through the compressor, the speed of rotation of the compressor and the efficiency of the compressor as a function of the pressure upstream of the compressor.
• a sensor for measuring the air pressure downstream of the compressor and the system includes means for correcting the set value of the compressor geometry as a function of the pressure of the compressor. air measured downstream. Such a correction makes it possible to vary the compression ratio, the flow rate of air passing through the compressor, the speed of rotation of the compressor and the efficiency of the compressor as a function of the pressure downstream of the compressor.
• the control system advantageously comprises a sensor for measuring the geometry of the compressor and a proportional-integral-derivative regulator receiving the difference between the measured value of the geometry of the compressor and the reference value of the geometry of the compressor and capable of develop a control signal of the geometry of the compressor.
• the system may also include means for calculating a prepositioning value of the geometry of the compressor and means for correcting the signal produced by the controller taking into account said prepositioning value.
• This prepositioning value represents a set value of the geometry. compressor that can be mapped and simplifies regulation in steady state. During transient phases, the addition of such a prepositioning value makes it possible to improve the accuracy and the response speed of the regulation.
• the invention also relates to a method for controlling a turbocharger for a motor vehicle internal combustion engine of the type comprising a variable geometry turbine and a variable geometry compressor, in which the pressure is regulated. supercharging by changing the geometry of the turbine and the geometry of the variable geometry compressor is further regulated from a set value of the geometry of the compressor, said reference value being mapped as a function of the rotational speed of the engine and the fuel flow injected into the engine. It is also possible to apply at least one correction to the setpoint value, said correction being dependent on at least one of the parameters constituting the air flow through the compressor, the air temperature upstream of the compressor, the speed of rotation of the compressor, the air pressure upstream or downstream of the compressor.
• FIG 1 shows schematically the main elements constituting the turbocharger of an internal combustion engine with its regulating device
• FIG. 2 schematically shows the main elements included in the electronic control unit for the development of the setpoint value of the boost pressure and the control signal of the variable geometry turbine; and
• FIG. 3 illustrates an embodiment of the main elements contained in the electronic control unit for developing the control signal of the variable geometry compressor.
• the internal combustion engine generally referenced 1
• the turbocharger 2 referenced.
• the operation of the internal combustion engine 1 is controlled by the unit.
• UCE electronic control referenced 3 which also ensures, as will be seen later, the control of the turbocharger 2.
• the engine 1 comprises, in the illustrated example, four cylinders 4 receiving compressed air via an intake manifold 5, the exhaust gas being conveyed by an exhaust manifold 6.
• an intake manifold 5 the exhaust gas being conveyed by an exhaust manifold 6.
• an exhaust manifold 6 the exhaust gas being conveyed by an exhaust manifold 6.
• the fresh air symbolized by the arrow 9, first passes through an air filter 10 before being led through an air line 11 to the inlet of the turbocharger 2.
• a sensor 12, mounted in the pipe 11 is able to measure the temperature of the air supplied to the turbocharger 2, ie T air mes .
• a second sensor 13 measures the air flow supplied to the turbocharger 2, that is to say Q air my -
• the turbocharger 2 comprises a variable geometry compressor 14 and a variable geometry turbine 15.
• the compressor 14 and the turbine 15 are mounted on a common shaft 16.
• the compressor 14, like the turbine 15, can for example be equipped with a plurality of blades of variable orientation, not shown in the figure, and comprise control means for varying the orientation of these blades, that is to say the geometry of the compressor or the turbine.
• Such a device with steerable blades can be replaced, for the turbine 15, by a bypass line equipped with a discharge valve (called "wastegate") which allows, as well as the blades with variable orientation, to modify the air pressure at the outlet of the compressor.
• wastegate discharge valve
• this modification of the geometry includes both devices with pivoting vanes and other types of devices for obtaining the same effect.
• Compressed air from the compressor 14 is fed to the intake manifold 5 after passing through a heat exchanger
• the exhaust gas from the exhaust manifold 6 is fed to the inlet of the turbine 15 which is thus rotated, and which in turn drives the compressor 14 through the shaft 16.
• the exhaust gases from the turbine 15 are conveyed by the exhaust line 18 which comprises various anti-pollution treatment devices, such as an oxidation catalyst and / or a filter. particles, the assembly being symbolized by block 19 in FIG.
• the system also comprises various sensors, and in particular a sensor 20 capable of measuring the air pressure in the intake manifold, ie P2 mes ; a sensor 22 for measuring the air pressure in the pipe 11, that is to say upstream of the compressor 14, Pl mes ; a sensor 23 for measuring the position of the geometry of the compressor 14, that is CGV pos mes ; and a sensor 24 for measuring the speed of rotation of the compressor 14 and its drive shaft 16, NC mes .
• the electronic control unit 3 comprises, in particular, a calculation block 25 capable of calculating a set value for the supercharging pressure P2 cons .
• the calculation block 25 receives various input parameters, in particular the value of the atmospheric pressure via the connection 26, the temperature of the air at the inlet of the compressor 14, T airmes , as measured by the sensor 12, this temperature value being supplied to it by the connection 27.
• the calculation block 25 also receives a signal corresponding to the rotational speed of the motor N via the connection 28 and, via the connection 29, a fuel flow signal injected into the engine cylinders 1.
• the output signal of the calculation block 25 corresponding to the setpoint value of the boost pressure P2 cons is fed through the connection 30 to a regulating device 31, also included in the electronic control unit 3
• the regulating device also receives as input the measured value of the air pressure in the intake manifold, P2 mes by the connection 32.
• the regulating device 31 allows the regulation of the supercharging pressure P2 by acting by the output signal, brought by the connection 33, to the geometry of the turbine 15.
• the electronic control unit 3 also comprises a calculation block 34, capable of calculating a set value of the position of the geometry of the compressor 14, which value is noted in FIG. 1 CGV pos .
• the calculation block 34 receives as input the value of the rotational speed N of the engine via the connection 35 and the value of the fuel flow d through the connection 36.
• the calculation block 34 receives also in input the value of the air temperature at the inlet of compressor 14 as measured by the sensor 12, the value T air, my P ar ⁇ a connection 37, the value of air flow penetrating in the compressor 14, ie Q air, mes , as measured by the sensor 13, this value coming from the connection 38, the value of the air pressure at the inlet of the compressor 14 measured by the sensor 22, value Pl my transmitted via the connection 39, the rotational speed of the compressor as measured by the sensor 24, or CN my supply via the connection 40, and finally the value of the air pressure at the outlet of compressor 14 as measured by the sensor 20, the value P2 mes provided by the connection 41.
• the output signal of the calculation block 34 that is to say the set value of the geometry of the compressor 14, CGV poscons , is transmitted by the connection 42 to a regulating device 43 of the geometry of the compressor 14.
• the output signal of the regulation 43 transmitted via the connection 44 acts on the position of the geometry of the compressor 14.
• the set value of the boost pressure P2 cons is mapped in a block 45 stored in the electronic control unit according to the rotation speed N of the engine and the fuel flow d. According to these two input parameters, the map 45 thus makes it possible to determine a setpoint value for the boost pressure P2 cons which appears on the connection 46. However, it is preferable to make various corrections of this setpoint value according to various environmental parameters, in order to improve the operation of the system. In the example illustrated in FIG. 2, two corrections are provided: one as a function of the atmospheric pressure, and the other as a function of the temperature of the air entering the compressor. To perform the first correction as a function of the atmospheric pressure, the value of the atmospheric pressure, P atm is brought to a block 47 which emits a correction signal via the connection 48.
• a mapping of the boost pressure according to the operating mode rotation N of the engine and of the fuel flow d, identical to that of the block 45, is included in a block 49, which emits a signal supplied by the connection 50 to a corrector 51.
• the correction thus obtained is fed to an adder 52, to change the set point from block 45.
• the second correction is performed under the same conditions, the block 53 receiving the temperature of the air at the inlet of the compressor 14 as measured by the sensor 12 and emitting on the connection 54 a correction signal which modifies in the corrector 55 the reference value of the supercharging pressure resulting from a mapping identical to that of the block 45 contained in a block 56.
• the value thus corrected is fed to an adder 57, which makes it possible to apply this second correction to the set point boost pressure.
• the thus corrected setpoint value P2 cons is fed to the regulating device 31, which comprises a first adder 58 also receiving the measured value of the supercharging pressure P 2, as measured by the sensor 20.
• the difference between the setpoint value and the measured value is brought by the connection 59 to a regulator which is preferably of the proportional integral derivative (PID) type, referenced 60 in FIG. 2
• the output signal of the regulator 60 constitutes the control signal of the variable geometry of the turbine 15
• a second adder 61 which receives a prepositioning value of the geometry of the turbine 15 via the connection 62.
• This prepositioning value constitutes, as it were, a predetermined value of the control signal of the geometry of the turbine.
• turbine 15 for the operating point considered of the engine In the stabilized phase of the motor operation, this prepositioning value constitutes the value of the control signal, so that the regulator 60 does not act.
• the set point of the position of the geometry of the compressor 14 is mapped and stored in a block 63 as a function of the speed N of the engine and the flow rate of the fuel injected.
• the set value thus obtained appearing on the connection 64 at the output of FIG. in the example illustrated in FIG. 3, the mapping 63 is the subject of five successive corrections which are each made in the same manner. Only the manner in which the first correction is performed is described. flow of air passing through the compressor 14, the air flow rate which is measured by the sensor 13 and which has the air Q value. This value, brought to the input of a block 65a, allows the development of a correction signal on the connection 66a, this signal being fed to a combination block 67a.
• the block 67a also receives the value of the position of the geometry of the compressor established by the block 68a which contains in memory the same mapping as the block 63 and sends on its output 69a a signal corresponding to the set value of the Positioning of the geometry of the compressor 14. The correction thus produced appears on the connection 70a and is brought to the negative input of an adder
• the second correction is made as a function of the temperature of the air entering the compressor 14, as measured by the sensor 12.
• This value T air mes is thus brought to a block 65b, the correction being carried out under the same conditions as previously and the corresponding blocks shown in Figure 3 with the same references assigned an index b.
• the third correction is made according to the speed of rotation of the compressor, as measured by the sensor 24.
• the measured value NC mes is brought to a block 65c and the correction is performed under the same conditions as before, the corresponding blocks bearing the same references assigned to the item c.
• the fourth correction is performed according to the pressi one air to the inlet of the compressor 14, as measured by the sensor 22, the value P s my 65d is supplied to a block.
• the correction is carried out under the same conditions as above by means of the blocks illustrated in Figure 3 which have the same references assigned the index d.
• the fifth correction is made according to the output pressure of the compressor 14, as measured by the sensor 20, the corresponding value P 2mes being brought to a block 65e.
• the correction is performed under the same conditions as before by blocks illustrated in FIG. 3 and bearing the same references assigned to the index e.
• the setpoint value of the position of the geometry of the compressor 14 produced from the map stored in the block 63 is thus successively subjected to five corrections which make it possible to improve the operation of the regulation. In another embodiment, it would be possible to use only some of these corrections.
• the corrected setpoint appears on the connection 72 at the output of the adder 71e. It is brought to the input of the regulating device 43.
• This comprises a regulator 73 which is, in the example illustrated, a derivative integral proportional type regulator (PID).
• PID derivative integral proportional type regulator
• the regulator 73 receives on its input the difference between the set value developed in the block 34 as indicated above and the measured value of the position of the geometry of the compressor 14 as measured by the sensor 23, ie the value CGV pos mes .
• the output signal of the regulator 73 constitutes the control signal for acting on the geometry of the compressor 14.
• a second adder 75 is also provided, which receives, via the connection 67, a prepositioning value of the geometry compressor 14.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Supercharger (AREA)

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• 2005
  • 2005-10-21 FR FR0510769A patent/FR2892451A1/fr active Pending
• 2006
  • 2006-10-02 EP EP06831261A patent/EP1941139A1/de not_active Withdrawn
  • 2006-10-02 WO PCT/FR2006/050975 patent/WO2007045781A1/fr active Application Filing

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