METHOD FOR MULTIVARIABLE ENGINE CONTROL USING CAMSHAFT ADJUSTMENT WITH A COMBINED HUMIDITY AND EXHAUST GAS RECIRCULATION (EGR) DILUTION VALUE FOR PLANNING RESTRICTIONS AND DETERMINING AN EGR SEQUENCE VALUE

Abstract

Method (700) for multivariable torque control of a vehicle (100), comprising the method (700): Configuring (705) a processor (152) arranged in a multivariable control unit (230) and programmed with a set of instructions to determine a set of references associated with exhaust gas recirculation (EGR); Implementing an algorithm by the processor (152) based on the engine temperature (102) and at least one reference determined from the set of references associated with the EGR to generate one or more instructions for controlling a set of actuators; Optimizing at least one cam phase position by the controller on the basis of a command generated to at least one actuator from the set of actuators by the processor (152) in order to apply a suitable motor torque (102) for the vehicle drive (100); Restricting (730), by the processor (152), a permissible range of cam phases associated with operations of an EGR valve (170) for a set of cams, based on amounts of moisture and EGR introduced through the EGR valve (170) during a combustion phase of vehicle operation (100); and Providing an amount of drive torque by a motor (102) of the vehicle (100) according to the instructions of the processor (152).

Description

[0001] The technical field generally relates to internal combustion engines and in particular to a system and method for multivariable engine control using camshaft adjustment with a combined humidity and EGR dilution value, implementing planned camshaft adjustment references and limits as well as reference EGR setpoints to optimize engine performance.

[0002] The exhaust gas recirculation (EGR) valve recirculates exhaust gases back into the engine's intake system to improve engine efficiency, reduce fuel consumption, and lower NOx emissions. Engine control systems are designed to manage the engine's output torque to achieve the desired torque. However, conventional engine control systems do not control the engine's output torque as precisely as desired because they do not adequately account for other variables related to ambient humidity and intake air dilution, which can affect the air-fuel mixture and reduce engine performance. Furthermore, conventional engine control systems do not provide a rapid response to control signals or coordinate engine torque control among the various components that influence the engine's output torque.

[0003] US Patent 2018 / 0 195 487 A1 discloses a control device for an internal combustion engine that appropriately controls the compression ratio and ignition timing before the target compression ratio, determined according to humidity, is reached. The control device controls the internal combustion engine, which comprises a cylinder, a humidity sensor for detecting the moisture content of the ambient air supplied to the cylinder, a compression ratio adjustment mechanism for changing the cylinder's compression ratio, and an ignition device for igniting the air-fuel mixture in the cylinder. The control device includes a compression ratio control unit that controls the compression ratio adjustment mechanism and an ignition control unit that controls the ignition timing of the ignition device.Corresponding characteristics between compression ratio and ignition timing are determined for each humidity level according to a predetermined operating condition of the internal combustion engine. The compression ratio control unit determines a target compression ratio for the variable compression ratio mechanism based on the detected humidity. While the variable compression ratio mechanism adjusts the compression ratio to the target ratio, the ignition control unit controls the ignition system based on corresponding characteristics determined according to the detected humidity.

[0004] German patent DE 10 2018 102 859 A1 discloses a method for adjusting the phase of the opening and closing of intake and exhaust valves of internal combustion engines relative to the rotation of the crankshaft. The method is based on changes in engine speed, engine load, and relative ambient humidity. A set of cam position reference values ​​and limits, based on engine speed, engine load, and humidity, is used. These values ​​are contained in lookup tables that set and limit the cam position and valve overlap.

[0005] US Patent 2018 / 0112616A1 discloses an engine torque and emissions control (ETEC) system and a method for using such systems and motor vehicles with engines. The ETEC system for operating an internal combustion engine assembly comprises an engine sensor for monitoring engine torque, an exhaust gas sensor for monitoring nitrogen oxide (NOx) emissions from the internal combustion engine assembly, and an engine control unit that communicates with the engine sensor, the exhaust gas sensor, and the internal combustion engine assembly.The engine control unit is programmed to: receive desired engine torque and NOx output data; determine the desired engine torque and NOx output, as well as the desired reference values ​​for engine operation and exhaust operation, from the current engine torque and NOx output data; determine an engine operation control command and an exhaust operation control command from the desired reference values ​​for engine operation and exhaust operation; and control the operation of the internal combustion engine arrangement via the engine operation and exhaust operation control commands.

[0006] Accordingly, it is desirable to provide improved methods and systems for a multivariable engine control system that controls one or more camshaft adjusters and an EGR valve in order to introduce planned constraints in the operation of the camshaft adjusters and to maintain acceptable combustion stability under varying EGR and ambient humidity operating conditions.

[0007] Accordingly, it is desirable to provide improved methods and systems for a variable engine control system that controls a set of inlet and exhaust camshaft adjusters in combination with external EGR to improve the control of the internal combustion engine and to simplify a variety of effects caused by moisture and EGR into a single value that is used in generating at least one command to restrict the operation of one or more camshaft adjusters.

[0008] Furthermore, other desirable features and properties of the present disclosure will become apparent from the following detailed description and the attached claims in conjunction with the attached drawings and the aforementioned technical field and background.

[0009] In an exemplary embodiment, a method for multivariable torque control of a vehicle is provided.

[0010] The method comprises configuring a processor, located in a multivariable control unit and programmed with a set of instructions to determine a set of references associated with exhaust gas recirculation (EGR); implementing an algorithm by the processor, based on the engine temperature and at least one reference determined from the set of references associated with the EGR, to generate one or more commands for controlling a set of actuators; optimizing, by the processor, at least one cam phase position by the control unit based on a generated command to at least one actuator of the set of actuators, in order to apply a suitable engine torque for vehicle propulsion;Limit, by the processor, a permissible range of cam phases associated with operations of an EGR valve for a set of cams, based on amounts of moisture and EGR introduced through the EGR valve during a combustion phase of vehicle operation; and provide an amount of drive torque by a vehicle engine in accordance with instructions provided by the processor.

[0011] In at least one exemplary embodiment, the method further comprises the use of the set of camshaft adjusters, comprising intake and exhaust cams, by the processor in combination with external EGR to improve the control of an internal combustion engine; and the simplification by the processor of a multitude of effects caused by moisture and EGR into a single value for use in generating at least one instruction to restrict the operation of one or more camshaft adjusters.

[0012] In at least one exemplary embodiment, the method further comprises the combination of humidity and EGR values ​​by the processor into a single dilution value as a basis for planning the set of camshaft adjuster constraints.

[0013] In at least one exemplary embodiment, the method further comprises the adjustment of the values ​​of the set of camshaft adjuster limits by the processor in order to optimize engine performance while simultaneously protecting against poor combustion stability.

[0014] In at least one exemplary embodiment, the method further comprises that a value for an EGR reference is based on one or more values ​​contained in a set of calibration tables with at least one high barometric value and one low barometric pressure value.

[0015] In at least one exemplary embodiment, the method further comprises setting the EGR reference by the processor based on a set of values ​​associated with humidity, engine coolant and air temperature.

[0016] In at least one exemplary embodiment, the method further comprises the tuning of a coefficient by the processor to adjust the value of the EGR reference based on the set of values ​​associated with humidity, engine coolant and air temperature.

[0017] In at least one exemplary embodiment, the method further comprises the use of a current dilution value by the processor as input to interpolate between a set of dilution values, including low dilution values, nominal dilution values ​​and maximum dilution values, and a corresponding set of calibration tables to determine a set of camshaft adjuster constraints, including a maximum intake phase lead constraint, a maximum intake phase delay constraint, a maximum exhaust phase lead constraint and a maximum exhaust phase delay constraint.

[0018] In at least one exemplary embodiment, the method further comprises the processor reducing the amount of exhaust gas recirculation (EGR) in response to high humidity in order to maintain a constant dilution value.

[0019] In at least one exemplary embodiment, the method comprises controlling the operation of the EGR valve by the processor by calculating a percentage value of the EGR reference, which is used as the basis for a target setpoint; determining the percentage value of the EGR reference at low and high atmospheric pressures by the processor based on the values ​​contained in the set of calibration tables; applying the set of values ​​associated with the measured barometric pressure by the processor and using an interpolation function to determine the set of values ​​from the set of calibration tables on which an initial percentage value of the EGR reference is determined;and setting the percentage value of the EGR reference in accordance with a current humidity by the processor using a linear relationship function between the values ​​of the current humidity and the percentage value associated with an EGR reduction.

[0020] In at least one exemplary embodiment, the method comprises using a set of camshaft adjuster values ​​from a first, a second, and a third set of camshaft adjuster calibration tables, including a first calibration table containing cold camshaft adjuster values, a second calibration table containing warm camshaft adjuster values, and a third calibration table containing EGR camshaft adjuster values; mixing a cold-warm scale mixture containing values ​​between zero and one during engine warm-up, wherein the values ​​of the cold-warm scale mixture form the basis for applying the interpolation function between the cold camshaft adjuster values ​​and the warm camshaft adjuster table values;Further mixing occurs when EGR is introduced, including calculating the value for an EGR mixing factor by dividing a final percentage EGR reference by a nominal percentage value of the EGR reference corresponding to the current humidity. The EGR mixing factor provides a basis for applying the interpolation function between the warm camshaft adjuster values ​​and the EGR camshaft adjuster values; and generating the set of values ​​as reference target values ​​corresponding to camshaft adjuster commands to provide the amount of drive torque by the vehicle's engine in accordance with the instructions provided by the processor.

[0021] An example describes a system for the multivariable torque control of a vehicle. The system comprises an engine; and a processor located in a multivariable control unit coupled to the engine and configured to: determine a set of references associated with the exhaust gas recirculation (EGR); implement an algorithm based on an engine temperature and at least one reference determined from the set of references associated with the EGR to generate one or more commands for controlling a set of actuators; optimize at least one cam phase position by the controller based on a generated command to at least one actuator of the set of actuators to apply a suitable engine torque level for vehicle propulsion;Limiting a permissible range of cam phases associated with EGR valve operations for a set of cams, based on amounts of moisture and EGR introduced through the EGR valve during a combustion phase of vehicle operation; and providing a quantity of drive torque by the vehicle's engine in accordance with instructions provided by the processor.

[0022] In one example, the system further includes the processor being configured to use the set of camshafts, including intake and exhaust cams, in combination with external EGR to improve the control of the internal combustion engine; simplifying a variety of effects caused by moisture and EGR into a single value, which is used to generate at least one command to restrict the operation of one or more camshaft adjusters.

[0023] In one example, the system includes the processor being further configured to combine the humidity and exhaust gas recirculation values ​​into a single dilution value, which serves as the basis for planning the set of camshaft adjuster constraints.

[0024] In one example, the system comprises, wherein the processor is further configured to adjust the values ​​of the set of camshaft adjuster constraints to optimize engine performance while protecting against poor combustion stability, wherein a value for an EGR reference is based on one or more values ​​contained in a set of calibration tables with at least one high barometric value and one low barometric pressure value.

[0025] In one example, the system includes the processor being further configured to set the EGR reference based on a set of values ​​related to humidity, engine coolant, and air temperature.

[0026] In one example, the system involves the processor being further configured to use a current dilution value as input to interpolate between a set of dilution values, including low dilution values, nominal dilution values, and maximum dilution values, and a corresponding set of calibration tables to determine a set of camshaft adjuster constraints, including a maximum intake phase advance constraint, a maximum intake phase retardation constraint, a maximum exhaust phase advance constraint, and a maximum exhaust phase retardation constraint.

[0027] In one example, the system includes the processor being further configured to: reduce the amount of EGR in response to high humidity levels in order to maintain a constant dilution value.

[0028] In one example, the system comprises, with the processor further configured to: control the EGR valve by performing a set of actions to: calculate a percentage value of the EGR reference, which is used as the basis for a target setpoint; determine the percentage value of the EGR reference at low barometric pressure and at high barometric pressure based on values ​​contained in the set of calibration tables; apply the set of values ​​associated with the measured barometric pressure and use an interpolation function to determine the set of values ​​from the set of calibration tables on which an initial percentage value of the EGR reference is determined;and adjusting the percentage value of the EGR reference in accordance with a current humidity by using a linear relationship function between the values ​​of the current humidity and the percentage value associated with an EGR reduction.

[0029] In one example, the system comprises, with the processor further configured to: use a set of camshaft adjuster values ​​from a first, a second, and a third set of camshaft adjuster calibration tables, including a first calibration table containing cold camshaft adjuster values, a second calibration table containing warm camshaft adjuster values, and a third calibration table containing EGR camshaft adjuster values; mix, during engine warm-up, a cold-warm scale mixture containing values ​​between zero and one, with the values ​​of the cold-warm scale mixture forming the basis for applying the interpolation function between the cold camshaft adjuster values ​​and the warm camshaft adjuster table values;Further mixing occurs when EGR is introduced, including calculating the value for an EGR mixing factor by dividing a final percentage EGR reference by a nominal percentage value of the EGR reference corresponding to the current humidity. The EGR mixing factor provides a basis for applying the interpolation function between the warm camshaft adjuster values ​​and the EGR camshaft adjuster values, and for generating the set of values ​​as reference target values ​​that correspond to the camshaft adjuster commands for the provision of drive torque by the vehicle's engine.

[0030] The present disclosure is described below in conjunction with the following drawings, where identical numbers denote identical elements and where: Fig. Figure 1 shows an exemplary diagram of a vehicle comprising a multivariable torque control system and other components of a drive system, various actuators that respond to commands to control the intake and exhaust cams of a vehicle control unit in accordance with different embodiments; Fig. Figure 2 shows an exemplary functional block diagram of a vehicle incorporating a multivariable torque control system for limiting camshaft adjustment operations by analyzing the effects on combustion caused by moisture and EGR in order to maximize engine power and stability, and determining the optimal camshaft phase positions by issuing various commands for camshaft adjustment operations in accordance with various exemplary embodiments; Fig. Figure 3 shows an exemplary diagram of a series of comparisons between introduced humidity and EGR in control modes for the low, nominal and maximum dilution values, combining humidity and dilution values ​​into a single dilution value that restricts the camshaft adjusters to maximize engine power, in accordance with various embodiments; Fig. Figure 4 shows an exemplary diagram of the set of calibration tables containing values ​​used to determine the three dilution setpoints for the control of one or more camshaft adjusters and an EGR valve by the multivariable control unit according to various exemplary embodiments; Fig. Figure 5 shows an exemplary diagram of the multivariable engine control, which controls one or more camshaft adjusters and an EGR value, with three sets of exemplary calibration tables for camshaft adjuster reference values ​​according to different exemplary embodiments; Fig. Figure 6 shows an exemplary diagram of a procedure for calculating the percentage EGR reference value, which is used by the multivariable control system as a target setpoint in accordance with various exemplary embodiments; and Fig. Figure 7 shows an example flowchart of the process described in the Fig. 1-6 described multivariable torque control of the vehicle with a set of notes associated with EGR and limitations for EGR, with steps to simply reduce the effects caused by moisture and EGR to a single dilution value for limiting camshaft adjustment operations in accordance with various exemplary embodiments.

[0031] The use of variable intake and / or exhaust camshaft timing in internal combustion engines allows for better control, resulting in optimal engine performance, increased fuel efficiency, and reduced emissions. However, under certain environmental conditions, the camshaft overlap must be limited depending on the ambient humidity to ensure good combustion stability. To achieve the optimal overlap, the humidity of the intake air can be measured or estimated. This humidity, along with an EGR dilution value, is then used to create a set of cam position limits that can be adjusted to optimize engine performance while preventing poor combustion stability.

[0032] Fig. Figure 1 shows a vehicle 100 according to an exemplary embodiment. As described in more detail below, the vehicle 100 includes an engine control module (ECM) 114 configured for multivariable torque control to limit camshaft adjustment operations by analyzing the effects of moisture and EGR on combustion in order to maximize the engine performance and stability of the vehicle 100 according to exemplary embodiments.

[0033] In various embodiments, Vehicle 100 comprises an automobile. Vehicle 100 may be any number of different types of automobiles, such as a sedan, station wagon, truck, or sport utility vehicle (SUV), and may be a two-wheel drive (2WD) vehicle (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD) vehicle, and / or various other types of vehicles in certain embodiments. In certain embodiments, Vehicle 100 may also include a motorcycle or other vehicle, such as an aircraft, spacecraft, watercraft, etc., and / or one or more other types of mobile platforms (e.g., a robot and / or other mobile platforms).

[0034] The vehicle 100 comprises a body 104 mounted on a chassis 116. The body 104 essentially encloses other components of the vehicle 100. The body 104 and the chassis 116 can together form a frame. The vehicle 100 also comprises a plurality of wheels 112. The wheels 112 are each rotatably connected to the chassis 116 near a corner of the body 104 to facilitate the movement of the vehicle 100. In one embodiment, the vehicle 100 comprises four wheels 112, although this may vary in other embodiments (e.g., for trucks and certain other vehicles).

[0035] A drive system 111 is mounted on the chassis 116, which drives the wheels 112, for example via the axles 117. In various embodiments, the drive system 111 includes a motor 102, which drives the wheels 112 via the axles 117 and also provides the drive torque for the automatic braking of the vehicle 100. In certain embodiments, the motor 102 comprises an internal combustion engine. In various other embodiments, one or more other types of motors 102 may also be included, such as a hybrid electric / internal combustion engine and / or one or more other different types of motors.

[0036] As shown in various embodiments, the drive system 111 also includes a transmission 113. In various embodiments, the transmission 113 can be shifted automatically and / or manually into different gears, e.g. into driving mode (D), parking mode (P), reverse gear (R) and so on.

[0037] In various embodiments, the vehicle 100 also includes an internal combustion engine 102 containing a piston 125. During the combustion stroke, the combustion of the air / fuel mixture drives the piston 125 away from top dead center (TDC), thereby driving the crankshaft 119. The crankshaft 119 is thus rotatable to provide a drive torque for propelling the motor vehicle, with the piston-cylinder assembly 99 configured to combust the air-fuel mixture to rotate the crankshaft 119. The combustion stroke can be defined as the time between the piston 125 reaching top dead center (TDC) and the time at which the piston 125 reaches bottom dead center (BDC).

[0038] During the exhaust stroke, the piston 125 begins to move away from top dead center and expels the combustion products (exhaust gases) through an exhaust valve 130. The exhaust valve 130 is configured to expel the exhaust gases from the piston-cylinder assembly 99. The combustion products are expelled from the vehicle via an exhaust system 134.

[0039] The intake valve 122 is controlled by an intake camshaft 140, while the exhaust valve 130 is controlled by an exhaust camshaft 142. Thus, the intake camshaft 140 is configured to rotate to control the intake valve 122, and the exhaust camshaft 142 is configured to rotate to control the exhaust valve 130. It is understood that the intake camshaft 140, or multiple intake camshafts 140, typically control a plurality of intake valves 122, which are connected to one or more cylinders 118 in one or more cylinder banks.

[0040] Likewise, the exhaust camshaft 142 or multiple exhaust camshafts 142 will typically control a plurality of exhaust valves 130, which are assigned to one or more cylinders 118 in one or more cylinder banks. It should also be understood that the intake valve 122 and / or the exhaust valve 130 may be controlled by devices other than camshafts, e.g., by camless valve actuators.

[0041] The timing at which the intake valve 122 opens and closes relative to the piston's top dead center (TDC) is modified by an intake camshaft adjuster 148. The intake camshaft adjuster 148 can, for example, be configured to control the rotation of the intake camshaft 140 by adjusting the intake cam phase angle. Similarly, the timing at which the exhaust valve 130 opens and closes relative to the piston's top dead center (TDC) is modified by an exhaust camshaft adjuster 150. The exhaust camshaft adjuster 150 can be configured to control the rotation of the exhaust camshaft 142 by adjusting the exhaust cam phase angle. A camshaft adjuster actuator module 158 controls the intake camshaft adjuster 148 and the exhaust camshaft adjuster 150 based on signals from the engine control module (ECM) 114.Optionally, a variable valve lift can also be controlled by the camshaft adjuster actuator module 158.

[0042] The powertrain system (i.e., the engine 102 and the exhaust system 134) of the vehicle 100 also includes an exhaust gas recirculation valve (EGR valve 170) configured to selectively recirculate a portion of the exhaust gases back to the intake manifold 110 via a selectively variable opening range of the EGR valve. The EGR valve 170 is controlled by an EGR actuator module 172 based on signals from the ECM 114.

[0043] The engine 102 also includes a humidity sensor 107. The humidity sensor can detect the water vapor concentration of the air entering the intake manifold 110 via the intake duct. The humidity sensor 107 can be located downstream of an EGR valve 170, but upstream of the intake valve 122. A relative humidity reading generated by the humidity sensor is an indicator of the humidity of the fresh air or a combination of fresh air and recirculated exhaust air, based on the position of the EGR valve 170.

[0044] The position of the crankshaft 119 is measured by a crankshaft position sensor 180. The rotational speed of the crankshaft 119, which is also the rotational speed of the engine 102, can be determined based on the crankshaft position. The temperature of the engine coolant is measured by an engine coolant temperature sensor (ECT) 182. The ECT sensor 182 is preferably located in the engine 102 or at another point where the coolant circulates, such as a radiator.

[0045] The pressure in the intake manifold 110 is measured with a MAP sensor (Manifold Absolute Pressure) 184. Optionally, the engine vacuum, i.e., the difference between the ambient air pressure and the pressure in the intake manifold 110, can also be measured. The mass flow rate of the air flowing into the intake manifold 110 is measured with a MAF sensor (Mass Airflow) 186.

[0046] In Fig. 1. The setpoints or target values ​​for the airflow-controlling engine actuators are determined based on the air torque request. More precisely, the air control module 228 determines a commanded wastegate opening range 266, a commanded throttle valve opening range 267, a commanded EGR valve opening range 268, a commanded intake cam phase angle 269, and a commanded exhaust cam phase angle 270 based on the air torque request 265 using model predictive control.

[0047] In various embodiments, the engine control module (ECM) 114 comprises a control unit (or computer system) 141 which controls the operation of the vehicle, including the use of the drive torque provided by the engine 102, in accordance with the instructions provided by the control unit 141, based on the processing carried out by the control unit 141 using the sensor data and other data and / or information obtained via the ECM 114.

[0048] The ECM 114 receives inputs from an atmospheric (i.e., barometric) sensor 181 to determine the ambient air pressure in or around the vehicle and uses these inputs in part to adjust the air / fuel ratio and ignition timing to the changing altitude conditions (and thus the density of the air entering the engine 102).

[0049] In various embodiments, the control unit 141 (and in certain embodiments) is arranged in a body of the vehicle 100. It becomes clear that the control unit 141 differs in a different way from the one in Fig. The embodiment shown in Figure 1 may differ. For example, the control unit 141 may be coupled to one or more remote computer systems and / or other control systems or otherwise utilize them, for example as part of one or more of the aforementioned devices and systems of the vehicle 100.

[0050] In the illustrated embodiment, the computer system of the control unit 141 comprises a computer system (here also referred to as the computer system) and includes a processor 152, a memory 144, a storage device 168, and a computer bus 150. The processor 152 performs the calculation and control functions of the control unit 141 and may comprise any type of processor or multiple processors, individual integrated circuits such as a microprocessor, or any suitable number of integrated circuits and / or printed circuit boards working together to perform the functions of a processing unit. During operation, the processor 152 executes one or more programs 153 contained in the memory 144 and, as such, controls the general operation of the control unit 141 and the computer system of the control unit 141, generally during the execution of the tasks specified in the Fig. 2-7 described processes.

[0051] Memory 144 can be any suitable type of memory. For example, memory 144 can include various types of dynamic random-access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and Flash). In certain examples, memory 144 is located on the same computer chip as the processor 152 and / or is housed together with it.

[0052] The bus 150 is used to transmit programs, data, status and other information or signals between the various components of the computer system of the control unit 141, and an interface (not shown) enables communication with the computer system of the control unit 141, e.g. from a system driver and / or another computer system, and can be implemented using any suitable method and device.

[0053] The storage device 168 can be any suitable type of storage device, including various types of random-access memory and / or other storage devices. In an exemplary embodiment, the storage device 168 includes a program product from which the memory 144 can receive a program 153 that executes one or more embodiments of one or more processes of the present disclosure, as described in the Fig. 2-7 are described.

[0054] The bus 150 can be any suitable physical or logical means for connecting computer systems and components. This includes, but is not limited to, direct, hard-wired connections, fiber optic technology, infrared, and wireless bus technologies. During operation, the program 153 is stored in memory 144 and executed by the processor 152.

[0055] It is evident that although this exemplary embodiment is described in connection with a fully functional computer system, those skilled in the art will recognize that the mechanisms of the present disclosure can be distributed as a program product with one or more types of non-transitory, computer-readable, signal-carrying media used for storing the program and its instructions and for carrying out its distribution, such as a non-transitory, computer-readable medium carrying the program and containing computer instructions stored therein to cause a computer processor (such as processor 152) to carry out and execute the program.

[0056] Such a program product can take a variety of forms, and the present disclosure applies equally regardless of the specific type of computer-readable signal-carrying media used to carry out the distribution. Examples of signal-carrying media include writable media such as floppy disks, hard disks, memory cards, and optical data carriers, as well as transmission media such as digital and analog communication links. In certain embodiments, cloud-based storage and / or other techniques may also be used. It is also acknowledged that the computer system of the control unit 141 may otherwise differ from that described in Fig. 1 can differ from the embodiment shown, for example in that the computer system of the control unit 141 can be coupled with one or more remote computer systems and / or other control systems or can otherwise use them.

[0057] Fig. Figure 2 shows an exemplary diagram of a multivariable torque control system that determines the optimal cam phase positions by issuing various commands for camshaft adjuster operations according to exemplary embodiments. Fig. Figure 2 shows a set of references of the reference module 205, which includes a percentage EGR reference module 210 for generating a set of signals indicating percentage values ​​associated with EGR references, and a set of camshaft adjuster reference modules for generating a set of signals associated with values ​​for camshaft adjuster references.

[0058] In embodiments, the set of references of the reference module 205 generates Y and U references, which are sent to a multivariable control unit 230 that implements an algorithm with a processor that partially uses the Y and U references for EGR percentage references (i.e., EGR Y). ref) in combination with Y and U restrictions generated by a restriction module 220 to output a set of U commands 240. The U commands 240 include (though not implemented) commands for actions related to the throttle valve, wastegate, camshaft adjusters, EGR valve, and ignition components.

[0059] In certain embodiments, the reference module 205 calculates a percentage value for the EGR reference via the percentage EGR module 210, in which a percentage EGR reference value is calculated and used as the target setpoint in the multivariable control system. The calibration tables contain values ​​for the percentage EGR setpoint at low and high atmospheric pressure, and the measured atmospheric pressure is used by the EGR reference module 210 to interpolate between these tables to determine the initial percentage EGR setpoint. The percentage EGR setpoint is adjusted to the current humidity based on a linear relationship between humidity and percentage EGR reduction.

[0060] The restriction module 220 implements a set of dilution camshaft adjuster restrictions 225, which outputs a set of restrictions for the operation of one or more camshaft adjusters via the multivariable control unit 230. In some embodiments, the dilution phase restrictions 225 include control over one or more camshaft adjusters. In some embodiments, the restriction module 220 implements a process that combines the humidity and EGR values ​​into a single dilution value, which is used to schedule the camshaft adjuster restrictions. The dilution phase restrictions are based on three dilution setpoints: Low dilution = k1 * Low humidity + k2 * Zero EGR, Nominal dilution = k1 * High humidity + k2 * Nominal EGR at high humidity, Maximum dilution = k1 * High humidity + k2 * Max.Each dilution setpoint has a corresponding set of camshaft adjuster limit tables for maximum advance and maximum retardation. An actual dilution value (k1 * humidity + k2 * EGR) is calculated and used for interpolation between the three sets of limit tables. The outputs of the limit tables are applied as limits to the multivariable controller 230. The camshaft adjuster conditions (generated by the condition module 220) can be set to optimize engine performance while preventing poor combustion stability.

[0061] In some embodiments, the camshaft adjuster reference module 215 determines the optimal camshaft adjuster positions depending on the engine temperature and the EGR rate. The camshaft adjuster reference module 215 uses a set of several (i.e., three or more) camshaft adjuster calibration tables, which include calibration tables with cold, warm, and EGR values, to determine the U commands 240 for the optimal camshaft adjuster position.

[0062] In certain embodiments, the camshaft adjuster reference module 215 processes cold-warm scaler mixtures from 0 to 1 during the engine's warm-up phase. These mixtures are used to apply an interpolation or estimation function between a set of values ​​in the cold and warm camshaft adjuster calibration tables. Once the cold-warm scaler reaches a value of 1, an EGR mixing factor is used for interpolation between the "warm" and "with EGR" camshaft adjuster tables. The EGR mixing factor is calculated by dividing the final % EGR reference by the nominal % EGR reference at the current humidity.

[0063] In embodiments, the multivariable control unit 230 implements multivariable engine torque / airflow control using a percentage value of the EGR reference (calculated by the reference module 205), which is received as input for determining the actuator position commands for the engine. This EGR reference (Y, U reference) is based on values ​​derived from calibration tables for high and low atmospheric pressure, as well as adjustments made for humidity, engine coolant, and ambient air temperature. The humidity adjustment uses a simple formula to reduce the EGR by a coefficient multiplied by the change in humidity. The effects of EGR and humidity on combustion are similar but of different orders of magnitude.The coefficient can be adjusted so that the effective dilution remains constant by changing the EGR depending on the humidity.

[0064] Fig. Figure 3 shows an exemplary block diagram of a series of comparisons between the introduced humidity and the EGR in the control modes for the low, nominal, and maximum dilution values, where the humidity and dilution values ​​are combined into a single dilution value that limits the camshaft adjusters to maximize engine power (according to one embodiment). Fig. Figure 3 shows that for a low dilution value of 302, the equivalent humidity without any EGR is represented as low. At a nominal dilution value of 304 for a dry condition with a relative humidity of 0.7%, the equivalent humidity to EGR ratio is 310, indicating a high percentage of EGR to equivalent humidity. For the moist condition with a relative humidity of 2.4%, the ratio 315 between equivalent humidity and EGR shows a lower percentage of EGR and equivalent humidity.

[0065] Similarly, for the maximum dilution values ​​306 for a dry condition with a dryness value for humidity of 0.7%, a similar ratio 320 of a higher percentage of EGR to equivalent humidity is shown, and for a moist condition with a humidity value of 2.4%, a lower percentage of EGR to humidity is (randomly) shown with the ratio 330. The range of permissible camshaft adjustment is then limited based on the humidity and EGR quantity, which is determined by the combined values ​​of the humidity and EGR values ​​by the in Fig. The individual dilution values ​​shown in Figure 3 are introduced for the low dilution 302, the nominal dilution 304 and the maximum dilution 306.

[0066] The individual dilution values ​​are calculated using the variables k1 and k2 and added as follows: Low dilution = k1 * Low humidity + k2 * Zero EGR, Nominal dilution = k1 * High humidity + k2 * Nominal EGR at high humidity, Maximum dilution = k1 * High humidity + k2 * Maximum EGR at high humidity. Each dilution target value has a corresponding set of camshaft adjuster limit tables for maximum advance and maximum retardation. An actual dilution value (k1 * humidity + k2 * EGR) is calculated and used for interpolation between the three sets of limit tables.

[0067] In exemplary embodiments, the system simplifies the effects of humidity and EGR into a single value via the low, nominal, and maximum dilution values, which allows the multivariable controller (230 of Fig. 2) makes it possible to limit the camshaft adjusters to maximize engine power, stability and efficiency.

[0068] In exemplary embodiments, a multivariable torque controller can be used, allowing movement of the airflow actuators, including the cams, away from their reference positions to more optimally generate the desired torque. The constraints implemented based on the individual dilution values ​​enable acceptable combustion stability under varying EGR and ambient humidity conditions. The constraints also account for the effects of humidity and EGR on combustion (shown in the diagrams in Fig. 3), which have similar effects on combustion, but to varying degrees. To account for the different orders of magnitude, the effects of humidity and EGR (as shown in Figure 3) can be considered. Fig. 3 shown) can be added by first multiplying humidity and AGR by the scaling factors k1 and k2 respectively.

[0069] Fig. Figure 4 shows the calibration tables for the camshaft adjuster conditions corresponding to low dilution 415, nominal dilution 425, and maximum dilution 435. Each dilution level has calibration tables for maximum intake phase lead, maximum intake phase retardation, maximum exhaust phase lead, and maximum exhaust phase retardation.

[0070] The current dilution value 405 is used for interpolation between the dilution values ​​of the low dilution values ​​410, the nominal dilution values ​​420 and the maximum dilution values ​​430 (i.e., the low, nominal and maximum dilution values ​​are in Fig. 3 corresponding to the low dilution value 302, the nominal dilution value 304 and the maximum dilution value 306) and their respective calibration tables to determine the maximum lead-in limit 440 for the inlet phase controller, the maximum delay limit 445 for the inlet phase controller, the maximum lead-in limit 450 for the outlet phase controller and the maximum delay limit 455 for the outlet phase controller.

[0071] In exemplary embodiments, the conventional camshaft adjuster control can also be used by means of values ​​from the tables for adjuster setpoints under different conditions.

[0072] Fig. Figure 5 shows an exemplary diagram of the multivariable engine control, which controls one or more camshaft adjusters and an EGR valve, with three sets of exemplary calibration tables for camshaft adjuster reference values ​​in accordance with different embodiments.

[0073] In Fig. The multivariable engine control process 500 includes a calibration table 510 with cold camshaft adjustment values, a calibration table 520 with warm camshaft adjustment values, and a calibration table 530 with EGR adjustment values. A cold / warm scaler 515 is configured based on the engine temperature. An EGR mixing factor 525 (i.e., the final percentage value of EGR Y) ref / nominal percentage of AGR Y ref) is configured after the engine has warmed up. The values ​​from all three calibration tables are interpolated using interpolation functions 535 and 540 with corresponding value pairs from the cold-warm calibration tables and the warm-EGR calibration tables to determine the camshaft adjuster U commands. ref 545 (i.e., camshaft adjuster reference targets) to determine.

[0074] If the cold-warm scaler 515 has a value less than 1, the estimation or interpolation is based on the values ​​of the cold-warm calibration table pair; otherwise, it is based on the values ​​of the warm-EGR calibration tables. Therefore, if the engine has not warmed up, the cold and warm tables are blended to determine the camshaft adjuster reference values. The cold-warm blending factor is determined by the engine temperature and the calibration tables. In an alternative embodiment, the camshaft adjusters can be controlled independently of the exhaust gas recirculation (EGR), but the stability and efficiency of the engine's combustion process may suffer without considering the EGR.

[0075] Fig. Figure 6 is an exemplary diagram of a procedure for calculating the percentage EGR reference value, which is used by the multivariable control system as a target setpoint in accordance with various embodiments.

[0076] In Fig. Figure 6 illustrates the procedure 600 for interpolation by the multivariable controller using percentage values ​​of EGR at low and high air pressures. Fig. Figure 6 shows a calibration table 605 containing percentage values ​​of high barometric pressures, and another calibration table 615 containing percentage values ​​of low barometric pressures, which are adjusted by an interpolation function 610 to provide an interpolated barometric pressure value. This interpolated barometric pressure value is then adjusted by an interpolation function 620 for an interpolated humidity value, which is subsequently temperature-adjusted to produce the percentage value of the EGR reference at output 640. In embodiments, the values ​​in the calibration tables are percentage base values ​​of the EGR reference values ​​for low and high barometric pressure, and each value is related to, or a function of, the engine speed per minute (RPM) and the desired airflow per cylinder (APC). Output 640 is based on the values ​​adjusted for humidity and temperature.

[0077] In embodiments, the values ​​of each of the calibration tables are adjusted by a humidity adjustment using the interpolation function 620 of -k multiplied by the current humidity minus the low humidity value (i.e., -k * (current humidity - low humidity)), which is then adjusted to a temperature adjustment function 625 by multiplication with a coolant temperature value or a constant (*K). coolanttemp ) 627 from a table 630 and the next multiple of a charge temperature value or a constant (*K chargetemp) 629 is sent from a table 635 to generate the output 640 of the percentage value of the EGR reference.

[0078] The measured barometric pressure 602 is used to interpolate a set of values ​​from the barometric calibration tables (i.e., the barometric pressure values ​​are adjusted by the interpolation function 610 from the barometric values ​​of the low / high calibration tables), which is then adjusted for humidity (i.e., the interpolated barometric pressure value is subsequently further interpolated based on a constant value multiplied by the amount of the current humidity decrease) to determine the initial percentage value of the AGR reference using an applied temperature adjustment function 625. The percentage value of the AGR reference is adjusted for the current humidity using a linear relationship between humidity and a percentage value of the AGR reduction. Fig. The humidity adjustment shown in Figure 6 is a relatively simple formula for reducing the EGR by a coefficient "K", multiplied by the change in humidity. The effects of EGR and humidity on combustion are similar, but differ in magnitude. The coefficient "K" can be adjusted so that the effective dilution remains constant by changing the EGR as a function of humidity.

[0079] Fig. Figure 7 is an exemplary flowchart of the vehicle's multivariable torque control, which is used in conjunction with the Fig. 1 - 6 of a series of references and limitations associated with EGR and camshaft adjusters are described, with steps to simply combine the effects caused by moisture and EGR into a single dilution value for limiting camshaft adjuster operations, in accordance with various embodiments.

[0080] In Fig. 7, Task 705, the process is initiated by a multivariable control unit implementing at least one processor programmed with a set of instructions to determine a set of references associated with exhaust gas recirculation (EGR).

[0081] In exemplary embodiments, the multivariable control unit implements an algorithm that uses engine temperature values ​​and at least one reference, determined from a set of references associated with the EGR fractions, to generate one or more commands for controlling a set of actuators. The multivariable control unit is configured to optimize at least one camshaft phasing position by controlling at least one actuator of the set of actuators based on a generated command and to apply appropriate engine torque for vehicle propulsion.In embodiments, the multivariable control unit is configured to apply constraints to optimize cam phase positions associated with EGR valve operations for a set of cams, based on moisture and EGR quantities introduced through the EGR valve during vehicle operation, and to provide a quantity of drive torque from a vehicle engine in accordance with instructions provided by the processor.

[0082] Task 710 implements a set of camshaft adjustments consisting of intake and exhaust cams in combination with external exhaust gas recirculation (EGR) to improve the control of an internal combustion engine. This is based on a set of instructions in the software to control a processor. The process simplifies a variety of effects caused by humidity and EGR during a vehicle phase into a single value, which is used to generate at least one command to restrict the operation of one or more camshaft adjusters. The process involves combining humidity and EGR values ​​into a single dilution value as the basis for planning the set of camshaft adjuster restrictions.

[0083] In Task 720, the process involves the processor adjusting the values ​​of the set of camshaft adjuster conditions to optimize engine performance while protecting against poor combustion stability. The EGR reference value is based on one or more values ​​contained in a set of calibration tables, which include high and low barometric pressure values. These values ​​are set by the processor based on a set of values ​​related to humidity, engine coolant, and ambient air temperature. The adjustment involves the processor fine-tuning a coefficient used in setting the EGR reference value based on this set of values ​​related to humidity, engine coolant, and ambient air temperature.

[0084] In Task 730, the processor generates a dilution value by using a current dilution value as input to interpolate between a set of low, nominal, and maximum dilution values ​​and a corresponding set of calibration tables to determine a set of camshaft adjuster constraints. The determined camshaft adjuster constraints include a maximum advance constraint for the intake phaser, a maximum retard constraint for the intake phaser, a maximum advance constraint for the exhaust phaser, and a maximum retard constraint for the exhaust phaser.

[0085] In task 740, the processor reduces the AGR amount as instructed in response to high humidity detected in the operating environment, in order to maintain a constant dilution value.

[0086] In Task 750, the procedure involves controlling the EGR quantity by having the processor issue control commands to control operations of the EGR valve, based on the implementation of an algorithm that calculates a percentage value of the EGR reference, which is used as the basis for a target setpoint; determining the percentage value of the EGR reference at low barometric pressure and high barometric pressure, based on the values ​​contained in the set of calibration tables;Applying the set of values ​​associated with the measured barometric pressure, and using an interpolation function to determine the set of values ​​from the set of calibration tables on which an initial percentage value of the EGR reference is determined, and adjusting the percentage value of the EGR reference in accordance with a current humidity by using a linear relationship function between the values ​​of the current humidity and the percentage value associated with an EGR reduction.

[0087] In Task 760, the processor can be instructed to use a set of camshaft adjuster values ​​from a first, second, and third set of camshaft adjuster calibration tables. The tables include a first calibration table containing cold camshaft adjuster values, a second calibration table containing warm camshaft adjuster values, and a third calibration table containing EGR camshaft adjuster values. Then, during the engine's warm-up period, a cold-warm scaler mixture containing values ​​between zero and one is generated. The values ​​of this cold-warm scaler mixture form the basis for applying the interpolation function between the cold camshaft adjuster values ​​and the warm camshaft adjuster table values.Next, a further mixing process for EGR mixing is introduced, which involves calculating the value for an EGR mixing factor by dividing a final percentage EGR reference value by a nominal percentage of the EGR reference value corresponding to the current humidity. The EGR mixing factor provides a basis for applying the interpolation function between the warm camshaft adjuster values ​​and the EGR camshaft adjuster values; and for generating the set of values ​​as reference target values ​​that correspond to camshaft adjuster commands to provide the amount of drive torque by the vehicle's engine in accordance with further instructions from the processor.

[0088] Accordingly, methods, systems and vehicles are provided that simplify the effects of moisture and EGR to a single value in order to control camshaft adjusters by means of constraints or limitations, thereby maximizing the engine power, stability and efficiency of a vehicle.

[0089] It becomes clear that the systems, vehicles, and procedures may differ from those depicted in the figures and described here. For example, vehicle 100 may differ from those shown in the figures. Fig. 1, its control system and / or its components of Fig. 1. In different embodiments, the steps of process 700 may differ from those in Fig. The steps shown in 1-6 may differ and / or different steps of the 700 process may occur simultaneously and / or in a different order than shown. Fig. The 7 shown will proceed.

Claims

[1] Method (700) for multivariable torque control of a vehicle (100), comprising the method (700): Configuring (705) a processor (152) arranged in a multivariable control unit (230) and programmed with a set of instructions to determine a set of references associated with exhaust gas recirculation (EGR); Implementing an algorithm by the processor (152) based on the engine temperature (102) and at least one reference determined from the set of references associated with the EGR to generate one or more instructions for controlling a set of actuators; Optimizing at least one cam phase position by the controller on the basis of a command generated to at least one actuator from the set of actuators by the processor (152) in order to apply a suitable motor torque (102) for the vehicle drive (100); Restricting (730), by the processor (152), a permissible range of cam phases associated with operations of an EGR valve (170) for a set of cams, based on amounts of moisture and EGR introduced through the EGR valve (170) during a combustion phase of vehicle operation (100); and Providing an amount of drive torque by a motor (102) of the vehicle (100) according to the instructions of the processor (152). [2] Method (700) according to claim 1, further comprising: Use (710) of the set of camshaft adjusters comprising intake and exhaust cams (142) by the processor (152) in combination with external EGR to improve the control of an internal combustion engine; and Simplifying a variety of effects caused by humidity and EGR by the processor (152) into a single value for use in generating at least one instruction to restrict the operation of one or more camshaft adjusters (148, 150). [3] Method (700) according to claim 2, further comprising: Combining moisture and EGR values ​​by the processor (152) to a single dilution value as a basis for planning the set of camshaft adjuster (148, 150) restrictions. [4] Method (700) according to claim 3, further comprising: Tuning (720) the values ​​of the set of camshaft adjusters (148, 150) limits by the processor (152) to optimize engine performance (102) while protecting against poor combustion stability, wherein a value for an EGR reference is based on one or more values ​​contained in a set of calibration tables of at least one high barometric value and one low barometric pressure value. [5] Method (700) according to claim 4, further comprising: Setting the EGR reference by the processor (152) based on a set of values ​​related to humidity, engine coolant (102) and air temperature. [6] Method (700) according to claim 5, further comprising: Tuning a coefficient to set the value of the EGR reference by the processor (152) on the basis of the set of values ​​associated with humidity, engine coolant (102) and air temperature. [7] Method (700) according to claim 6, further comprising: where the dilution value still includes: Using a current dilution value by the processor (152) as an input to interpolate between a set of dilution values, which includes low dilution values, nominal dilution values ​​and maximum dilution values, and a corresponding set of calibration tables to determine a set of camshaft adjuster limits (148, 150) which includes a maximum intake phaser advance limit, a maximum intake phaser retardation limit, a maximum exhaust phaser advance limit and a maximum exhaust phaser retardation limit. [8] Method (700) according to claim 7, further comprising: In response to high humidity, the processor (152) reduces the AGR amount to maintain a constant dilution value. [9] Method (700) according to claim 8, further comprising: Control (750) of the operation of the EGR valve (170) by the processor (152) by: Calculating a percentage value of the EGR reference by the processor (152), which is used as the basis for a target setpoint; Determining the percentage value of the EGR reference at low and high atmospheric pressure by the processor (152) based on the values ​​contained in the set of calibration tables; The processor (152) applies the set of values ​​associated with the measured barometric pressure and uses an interpolation function to determine the set of values ​​from the set of calibration tables on which an initial percentage value of the EGR reference is determined; and Setting (720) the percentage value of the AGR reference by the processor (152) in accordance with a current humidity using a linear relationship function between the values ​​of the current humidity and the percentage value associated with an AGR reduction. [10] Method (700) according to claim 9, further comprising: Using (760) a set of camshaft adjuster values ​​(148, 150) from a first, a second and a third set of camshaft adjuster (148, 150) calibration tables (605, 615) comprising a first calibration table (605, 615) with cold camshaft adjuster values ​​(148, 150), a second calibration table (605, 615) with warm camshaft adjuster values ​​(148, 150) and a third calibration table (605, 615) with EGR camshaft adjuster values ​​(148, 150); Mixing a cold-warm scaler mixture (515) containing values ​​between zero and one during the warm-up of the engine (102), wherein the values ​​of the cold-warm scaler mixture (515) form the basis for the application of the interpolation function between the cold camshaft adjuster values ​​(148, 150) and the warm camshaft adjuster table values ​​(148, 150); further mixing when EGR is introduced, comprising calculating the value for an EGR mixing factor (525) by dividing a final percentage EGR reference by a nominal percentage value of the EGR reference corresponding to the current humidity, wherein the EGR mixing factor (525) provides a basis for applying the interpolation function between the warm camshaft adjuster values ​​(148, 150) and the EGR camshaft adjuster values ​​(148, 150); and Generating the set of values ​​as reference target values ​​that correspond to camshaft adjustment commands to provide the drive torque by the engine (102) of the vehicle (100) according to the instructions provided by the processor (152).

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