System and method for heat flow calculation in a physically based piston temperature model

Abstract

A method (100) for providing a real-time calculation of the heat flow in an engine (10) comprising an engine block with a cylinder (14) and a wall surrounding the cylinder (14), wherein a piston is arranged in the cylinder (14) and is movable relative to the wall of the cylinder (14) in response to the timing of combustion in a combustion chamber within the cylinder (14), and the piston (28) is connected to a crankshaft via a connecting rod, the method comprising: Determining the temperature of the combustion inside the cylinder (14); Determining the average temperature of the cylinder wall; Determining the surface area of ​​the cylinder wall based on the time of combustion; Calculating in real time, via a controller, a heat component at the piston (28) based on the determined combustion temperature, the determined average temperature of the cylinder wall and the determined surface area of ​​the cylinder wall; and Controlling a state of the engine (10) based on an estimated temperature of the piston (28) derived from the real-time calculation of the heat content of the piston, wherein determining the surface area of ​​the cylinder wall further includes determining a displacement of the piston (28) based on an angular position of the crankshaft after top dead center, wherein the angular position is defined as the angular position of the crankshaft after releasing fifty percent of the heat of combustion (CA50).

Description

INTRODUCTION

[0001] Various vehicles have been developed, including an internal combustion engine that generates torque to ultimately drive the wheels, propelling the vehicles. The internal combustion engine may consist of an engine block with a cylinder and a cylinder wall, which together define a combustion chamber. A piston is located within the cylinder and moves relative to the cylinder wall in response to combustion. The piston's temperature changes depending on various operating conditions of the internal combustion engine, such as warm-up. Generally, a calibration table is used to predict the piston's temperature, but such a calibration table uses a constant table to predict a proportion of the heat from combustion in order to estimate the piston's temperature.

[0002] DE 10 2014 103 145 A1 describes a method for operating a vehicle's internal combustion engine in which, upon detection of a transient operating condition, target and actual temperatures of the combustion chamber and / or piston of a cylinder are determined. The temperature difference is then calculated and the combustion conditions are adjusted over time to optimize particulate emissions, exhaust gas values, and fuel consumption.

[0003] DE 10 2016 203 433 A1 discloses a method for determining an injection mode for injecting fuel into the combustion chamber of a cylinder of an internal combustion engine, in which the rotational speed (N) of the internal combustion engine and the cylinder wall temperature (ZT) of the cylinder are determined and the injection mode is determined depending on these values.

[0004] US 2017 / 0123392 A1 discloses a system and method for modeling a cylinder system of an engine, wherein the cylinder system comprises several components, including a cylinder and a piston slidably arranged therein. The method involves moving the piston within the cylinder, acquiring at least one first engine operating parameter during piston operation, and calculating at least one second engine operating parameter based on the first parameter. Based on these two parameters, the heat flux for at least one of the components and the operating cylinder pressure are calculated. DESCRIPTION

[0005] The object of the invention is to provide an improved method for the real-time calculation of heat flow. This object is achieved by the subject matter according to claim 1. Further developments are described in the dependent claims.

[0006] The present disclosure provides a method for the real-time calculation of heat flow in an engine. The engine comprises an engine block with a cylinder and a wall surrounding the cylinder. The engine also includes a piston, which is located in the cylinder and is movable relative to the cylinder wall in response to the timing of combustion in a combustion chamber within the cylinder. The piston is connected to a crankshaft via a connecting rod. The combustion temperature inside the cylinder is determined. An average cylinder wall temperature is determined. The surface area of ​​the cylinder wall is determined based on the timing of combustion. A heat fraction at the piston is calculated in real time via a controller based on the determined combustion temperature, the determined average cylinder wall temperature, and the determined cylinder wall surface area.The engine's state is controlled based on an estimated piston temperature, derived from a real-time calculation of the heat content of the piston.

[0007] The procedure optionally includes one or more of the following points: Determining the upper surface of the piston;

[0008] Calculating the heat content at the piston in real time is also based on the determined upper surface area of ​​the piston;

[0009] The real-time calculation of the heat component at the piston also includes the continuous updating of the estimated temperature of the piston at each subsequent time step;

[0010] Determining the total convection rate of the heat from the burned gas;

[0011] Calculating the heat contribution to the piston in real time is also based on the determined total convection rate of the combusted gas heat;

[0012] Determining the surface area of ​​the cylinder wall also includes determining a displacement of the piston based on an angular position of the crankshaft after top dead center;

[0013] Determining the surface area of ​​the cylinder wall also includes determining a radius of the crankshaft and a length of the connecting rod;

[0014] Determining the surface area of ​​the cylinder wall also includes the real-time calculation of the piston displacement based on the angular position of the crankshaft after top dead center, the radius of the crankshaft, and the length of the connecting rod; The angular position of the crankshaft after top dead center is defined more precisely than the angular position of the crankshaft after fifty percent of the combustion heat has been released;

[0015] Controlling the engine state involves injecting fuel into the combustion chamber based on the estimated temperature of the piston, which is derived from the real-time calculation of the heat content of the piston;

[0016] Controlling the engine state involves controlling the air-fuel ratio of the combustion chamber based on the estimated temperature of the piston, which is derived from the real-time calculation of the heat content of the piston;

[0017] Controlling the engine condition involves injecting oil into the cylinder around the piston based on the estimated temperature of the piston, which is derived from the real-time calculation of the heat content of the piston;

[0018] The real-time calculation of a rejection fraction based on the determined combustion temperature, the determined average cylinder wall temperature, the determined cylinder wall surface area, the determined piston top surface area, and the estimated piston temperature at each subsequent time step; and

[0019] Calculating the heat fraction to the piston in real time is more precisely defined than multiplying the rejection fraction by the total convection rate of the combusted gas heat.

[0020] The present disclosure also provides for an engine system for a movable platform. The system comprises an engine block with a cylinder and a wall surrounding the cylinder. The system also includes a crankshaft, which is supported by the engine block and rotatable relative to a longitudinal axis. The system further comprises a piston, which is connected to the crankshaft via a connecting rod. The piston is arranged in the cylinder and is movable relative to the cylinder wall in response to the timing of combustion in a combustion chamber inside the cylinder.The system also includes a control unit configured to: determine the combustion temperature inside the cylinder, determine the average temperature of the cylinder wall, determine the surface area of ​​the cylinder wall based on the timing of the combustion, and calculate in real time, via the control unit, a heat transfer coefficient for the piston based on the determined combustion temperature, the determined average temperature of the cylinder wall, and the determined surface area of ​​the cylinder wall. The control unit is also configured to control the engine's operating state based on an estimated piston temperature derived from the real-time calculation of the heat transfer coefficient for the piston.

[0021] The system optionally includes one or more of the following elements: the control is set up so that it determines an upper surface of the piston; the control system is set up to calculate a rejection fraction in real time, based on the determined combustion temperature, the determined average cylinder wall temperature, the determined cylinder wall surface area, the determined piston top surface area, and the estimated piston temperature at each subsequent time step; the control is set up to determine a total convection rate of the burned gas heat, and the calculated real-time heat fraction to the piston further includes the control which is set up to multiply the rejection fraction by the total convection rate of the burned gas heat; the control system is set up to control the state of the engine, which further includes the control system set up to signal a fuel injector to inject fuel into the combustion chamber, based on the estimated temperature of the piston as derived from the real-time calculation of the heat content of the piston; the control system is set up to control the state of the engine, which further includes the control system set up to control an air-fuel ratio of the combustion chamber based on the estimated temperature of the piston, as derived from the real-time calculation of the heat content of the piston; and the control system is set up to control the state of the engine, which further includes the control system set up to signal an oil injector to inject oil into the cylinder around the piston, based on the estimated temperature of the piston as derived from the real-time calculation of the heat content of the piston.

[0022] The detailed description and figures (FIGS) are supporting and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some preferred embodiments and other configurations for carrying out the claims have been described in detail, there are various alternative designs and configurations for implementing the disclosure defined in the appended claims. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 is a schematic cross-sectional view of a motor for a movable platform with a piston in a top dead center position. Fig. Figure 2 is a schematic representation of the engine with the piston after top dead center. Fig. Figure 3 is a schematic representation of the piston after top dead center, where top dead center is identified by the line TDC. DETAILED DESCRIPTION

[0023] Those with ordinary skill in the field will recognize that all directional references (e.g., above, below, high, upward, downward, above, below, left, right, vertical, horizontal, etc.) are used descriptively for the FIGS. to facilitate the reader's understanding and do not represent any limitations (e.g., regarding position, orientation, or use, etc.) of the scope of disclosure as defined by the accompanying claims.

[0024] Referring to the FIGS., in which identical reference numerals indicate identical or corresponding parts in the different views, a motor 10 for a moving platform, such as a vehicle, is generally in Fig. Figure 1 illustrates this. Non-restrictive examples of the mobile platform could be a car, truck, motorcycle, all-terrain vehicle, agricultural vehicle, watercraft, aircraft, or any other suitable mobile platform. Additionally, non-restrictive examples of the vehicle application could include a diesel / gas-powered vehicle, a hybrid vehicle, etc. It is estimated that the engine 10 could alternatively be used in a non-vehicle-related application, such as agricultural equipment, stationary platforms, stationary power plants, robots, etc.

[0025] In certain configurations, engine 10 can be an internal combustion engine, is generally in Fig. Figure 1 shows the motor 10, which comprises a variety of components that work together to transmit the torque, and some of these components are discussed below.

[0026] Continuing from Fig. The engine 10 comprises an engine block 12 with a cylinder 14 and a wall 16 surrounding the cylinder 14. The cylinder 14 defines a combustion chamber 18. The engine 10 may include a cylinder head 20 attached to the engine block 12 and an oil pan containing a liquid 22, such as oil 22, etc. The engine 10 further comprises a crankshaft 24 supported by the engine block 12, and the crankshaft 24 is rotatable relative to a longitudinal axis 26. In certain configurations, the crankshaft 24 is rotatable about the longitudinal axis 26. The torque is transmitted from the crankshaft 24 via a gearbox and final drive to wheels to propel the movable platform.

[0027] With reference to Fig. 1 and Fig. 2. The engine 10 also contains a piston 28, which is arranged in the cylinder 14, and the piston 28 is movable within the cylinder 14. More precisely, the piston 28 is movable relative to the wall 16 of the cylinder 14 in response to the timing of combustion 34 in the combustion chamber 18 inside the cylinder 14. Therefore, the wall 16 of the cylinder 14 axially surrounds the piston 28 relative to a central axis 30. Generally, the central axis 30 is transverse to the longitudinal axis 26, and in certain configurations, the central axis 30 is perpendicular to the longitudinal axis 26.

[0028] The piston 28 is connected to the crankshaft 24 via a connecting rod 32. The movement of the piston 28 is caused by the combustion 34 in the combustion chamber 18. More precisely, when a spark from a spark plug 36 ignites an air / fuel mixture, combustion 34 occurs, which moves the piston 28 along the central axis 30, which in turn causes movement of the connecting rod 32 and the crankshaft 24. The timing of combustion 34 (which can also be called the combustion point) determines when the combustion 34 occurs to move the piston 28, and the combustion point can be adjusted. Combustion 34 is discussed further below.

[0029] In certain configurations, the engine block 12 can define a plurality of cylinders 14 spaced apart from one another, and each of the cylinders 14 has a corresponding wall 16, with a corresponding piston 28 arranged in each of the corresponding cylinders 14. In certain configurations, the cylinder head 20 and the engine block 12 can work together to define the cylinders 14. When using a plurality of pistons 28, each of the pistons 28 is connected to the crankshaft 24 via corresponding connecting rods 32. The pistons 28 can move back and forth in their respective cylinders 14 in response to the combustion 34 in the combustion chamber 18. Generally, the pistons 28 move back and forth in their respective cylinders 14 along the central axis 30.

[0030] The combustion 34 of the air / fuel mixture exerts a force on the piston(s) 28, causing the piston(s) 28 to move in the respective cylinder(s) 14. This causes the connecting rod(s) 32 to rotate the crankshaft 24, thus generating torque. Generally, each of the pistons 28 in the respective cylinder(s) 14 is between a top dead center position (which is reached in Fig. (as shown in Figure 1) and is movable between bottom dead center (BDC). Top dead center (TDC) is reached when the piston 28 is at its highest point in cylinder 14. In other words, TDC is reached when the piston 28 is at its maximum distance from the longitudinal axis 26. When the piston 28 is at TDC, the crankshaft 24 is at a crank angle of approximately zero degrees. Therefore, before the piston 28 reaches TDC, the crankshaft 24 is at a crank angle of less than zero degrees. Bottom dead center (BDC) is reached when the piston 28 is at its lowest point in cylinder 14. In other words, BDC is reached when the piston 28 is at its minimum distance from the longitudinal axis 26.

[0031] The cylinder(s) 14 may be arranged in any suitable manner, and non-restrictive examples may be a V-engine arrangement, an inline engine arrangement and a horizontally opposed engine arrangement, as well as the use of both overhead camshafts and in-block camshafts.

[0032] To with Fig. 1. To continue, each of the cylinders 14 can define a corresponding combustion chamber 18. Thus, if more than one cylinder 14 is used, there is a combustion chamber 18 for each of the cylinders 14. In certain configurations, the engine block 12 and the cylinder head 20 each define a portion of the combustion chamber 18 for each of the respective cylinders 14. Additionally, the engine block 12 and / or the cylinder head 20 can define one or more intake ports 38 and one or more exhaust ports 40, each located adjacent to the respective cylinders 14. Generally, the combustion chamber 18 is located between the exhaust port 40 and the cylinder 14. If more than one cylinder 14 is used, each of the combustion chambers 18 is located between the respective exhaust ports 40 and the respective cylinders 14. The intake ports 38 and the exhaust ports 40 are in selective fluid communication with each of the combustion chambers 18.Each intake port 38 can supply the air / fuel mixture to a corresponding combustion chamber 18 via an intake manifold. After the combustion 34 of the air / fuel mixture, which can occur upon ignition by the spark plug 36, the exhaust port 40 carries the exhaust gases away from the combustion chamber 18 and from the engine block 12.

[0033] Continuing from Fig. 1. The engine 10 can also include one or more inlet valves 42 and one or more exhaust valves 44 that interact with the corresponding cylinders 14. In certain configurations, each of the cylinders 14 can have one or more interacting inlet valves 42 and one or more interacting exhaust valves 44. For example, each of the cylinders 14 can have two interacting exhaust valves 44 and two interacting inlet valves 42. In certain embodiments, the inlet and exhaust valves 42, 44 are supported by the cylinder head 20.

[0034] The intake valves 42 are movable between a first position, in which fluid communication through the intake port 38 is blocked, and a second position, in which fluid communication through the intake port is possible. Therefore, the intake valves 42 control when the air / fuel mixture is allowed to enter the combustion chamber 18. For illustration, [Figure 1] shows Fig. 1. The intake valve 42 is in the first position, in which it blocks the intake port. An eccentric part of a camshaft 46 works in conjunction with the intake valve 42. As the eccentric part of the camshaft 46 rotates into a specific position, it moves a rocker arm 48, and the rocker arm 48 moves the intake valve 42 into the second position. As the eccentric part moves past the rocker arm 48, a return spring 50 moves the intake valve 42 back into the first position, which closes the intake port 38.

[0035] The exhaust valves 44 are movable between a first position, which blocks fluid communication through the exhaust channel 40, and a second position, which allows fluid communication through the exhaust channel. Therefore, the exhaust valves 44 control when the exhaust gases are allowed to leave the combustion chamber 18. For illustration, Figure 44 shows... Fig. 1. The exhaust valve 44 is in its first position, in which it blocks the exhaust port. An eccentric part of a camshaft 46 works in conjunction with the exhaust valve. As the eccentric part of the camshaft 46 rotates into a specific position, it moves a rocker arm 48, and the rocker arm 48 moves the exhaust valve 44 into its second position. As the eccentric part moves past the rocker arm 48, a return spring 50 moves the exhaust valve 44 back into its first position, which closes the exhaust port 40.

[0036] When the piston 28 moves between top dead center and bottom dead center, it generally creates an intake stroke, and the intake valve 42 is correspondingly in its second position to allow the air / fuel mixture to flow into the combustion chamber 18. Furthermore, when the piston 28 moves between bottom dead center and top dead center, it creates an exhaust stroke, and the exhaust valve 44 is correspondingly in its second position to allow the exhaust gases to exit the combustion chamber 18. The engine block 12 may contain one or more channels 52 containing a coolant 54 to cool the wall(s) 16 of the cylinder(s) 14 during engine operation.

[0037] Various parameters or states of the motor 10 and the moving platform, etc., are monitored, and the collected data can be used to adjust different models and / or to operate the motor 10. Therefore, a control unit 56 can communicate with the motor 10 as well as with other components of the moving platform. The control unit 56 can control / operate various parameters or states of the motor 10 and / or other components of the moving platform. It should be noted that in certain configurations, more than one control unit 56 can be used.

[0038] Depending on the operating state of the engine 10, the temperature of the piston 28 can change. For example, during the warm-up phase of the engine 10, the engine block 12 (and in particular the wall 16 of the cylinder 14) and the piston 28 may be cold when the piston 28 begins to move in the cylinder 14. As the engine 10 continues to warm up, the wall 16 of the cylinder 14 and the piston 28 heat up further as the piston 28 moves within it. After the warm-up phase is complete, the wall 16 of the cylinder 14 and the piston 28 may reach a normal operating temperature. Real-time data regarding the temperature of the piston 28 can be used to improve various characteristics of the moving platform. In particular, it is desirable to perform real-time calculations of the heat flow in the engine 10, and especially real-time calculations of the heat flow to the piston 28, to improve various operating characteristics of the moving platform.

[0039] Therefore, a method 100 for the real-time calculation of the heat flow in engine 10 is presented here. Specifically, method 100 uses the real-time calculation of the heat flow to piston 28, which enables a more accurate determination of the heat flow in engine 10. This real-time calculation can be implemented in an algorithm that is a physically based piston temperature model. The heat flow to piston 28 changes constantly or varies with the operating conditions of engine 10, which change in real time.

[0040] The procedure 100 described here does not use a calibration table to represent the heat flux to piston 28. The calibration table would use a constant table to predict a heat flux to piston 28, which does not account for continuous temperature changes during the various operating conditions of engine 10. Therefore, the calibration table does not consider real-time changes in the heat flux to piston 28 during the different operating conditions of engine 10. Thus, when referring to real-time calculations of the heat flux to piston 28, this does not refer to the use of the calibration table. Instead, the controller 56 continuously calculates the heat flux to piston 28 in real time using various data and calculations discussed below.

[0041] Several advantages can be achieved through the method 100 described here. For example, a more accurate estimation of the heat flow to piston 28 can be achieved using method 100. This allows for more precise air-fuel supply to combustion chamber 18 and / or oil supply to cylinder 14 by monitoring the real-time heat flow to piston 28. Using real-time heat flow calculation to piston 28 can also contribute to reducing particulate emissions and / or provide a more robust engine 10 by reducing unusual or infrequent undesirable operating scenarios. Furthermore, the service life of piston 28 can be improved by using real-time heat flow calculation. Additionally, other calibrations and / or other models of the moving platform can be improved by using real-time heat flow calculation.

[0042] To return to the controller 56: The controller 56 is programmed to execute instructions embodying the procedure 100. The controller 56 can be a host computer or a distributed system, e.g., a computer such as a digital computer or microcomputer. The controller 56 contains a processor P and a memory M, where the memory M contains application-appropriate amounts of physical, non-temporary memory, e.g., read-only memory, optical, magnetic, flash memory, or other memory. Instructions can be stored in the memory M of the controller 56 and automatically executed via the controller 56's processor P to provide the respective control functionality.The controller 56 also includes application-specific amounts of random-access memory, electrically erasable programmable read-only memory, and the like, as well as a high-speed clock, analog-to-digital and digital-to-analog circuits, input / output circuits and devices, and suitable signal conditioning and buffer circuits. Therefore, the controller 56 can contain all the software, hardware, memory, algorithms, connections, sensors, etc., required for control, for example, to enable real-time calculation of the heat flow in the motor 10 and to adjust various parameters or states of the moving platform in response to the real-time calculation.It is estimated that the control unit 56 may also include any device capable of analyzing data from various sensors, comparing data, and making the necessary decisions required to control the calculation of heat flow and / or different models and / or different states of the motor 10.

[0043] In general, the control unit 56 can use, determine, and / or collect information or data about various temperatures (such as the cylinder wall 16, the piston 28, the combustion 34, the coolant 54, the oil 22, etc.), the position of the crankshaft 24, etc. The control unit 56 can communicate with various sensors, displays, etc., of the engine 10 and the moving platform to use, collect, compile, derive, and determine the information or data required to carry out the procedure 100.

[0044] For example, the controller 56 is set up to determine a temperature (T kämmen ) of the combustion 34 inside cylinder 14, and determine an average temperature (T Wand ) of the wall 16 of the cylinder 14. Furthermore, the control 56 is set up such that it controls an area (A w ) of the wall 16 of the cylinder 14 based on the time of combustion 34. The controller 56 uses this information to calculate in real time the heat flux, which provides an estimated temperature of the piston 28 used to control the engine state 10. Specifically, the controller 56 calculates a heat fraction (Q̇) in real time. KolbenFraktion) to the piston 28 based on the determined temperature of the combustion 34, the determined average temperature of the wall 16 of the cylinder 14 and the determined surface area of ​​the wall 16 of the cylinder 14. The surface area of ​​the wall 16 based on the time of combustion 34 and the heat fraction is discussed further below.

[0045] As mentioned above, various operating parameters or states of the moving platform can be adjusted in response to real-time calculations. For example, one state of motor 10 is controlled based on the estimated temperature of piston 28, which is derived from the real-time calculation of the heat transfer to piston 28. Different states of motor 10 can be controlled in response to the determination of the real-time heat flux, or more precisely, the heat transfer to piston 28, which provides the estimated temperature of piston 28 used in various models. In certain configurations, the controller 56 is set up to control one or more of the states of motor 10.For example, the controller 56 can control or signal a fuel injector 58 to inject fuel into the combustion chamber 18, based on the estimated temperature of the piston 28, derived from the real-time calculation of the heat fraction of the piston 28. As another example, the controller 56 can control the air-fuel ratio of the combustion chamber 18 based on the estimated temperature of the piston 28, derived from the real-time calculation of the heat fraction of the piston 28. As yet another example, the controller 56 can control or signal an oil injector 60 to inject oil 22 into the cylinder 14 around the piston 28, based on the estimated temperature of the piston 28, derived from the real-time calculation of the heat fraction of the piston 28. In certain configurations, the controller 56 can control more than one state of the engine 10, and other states are also possible, such as...B. the temperature of the coolant 54, the timing of the inlet and / or outlet valves 42, 44 etc.

[0046] Due to combustion 34, the piston 28 changes its position relative to the wall 16 of the cylinder 14, thereby changing the exposed area of ​​the wall 16 of the cylinder 14. Therefore, the exposed area of ​​the wall 16 changes with the timing of combustion 34. The exposed area of ​​the wall 16 of the cylinder 14 influences the heat transfer between the piston 28 and the wall 16 of the cylinder 14; therefore, a rejection ratio is determined via the control 56 and used to determine the heat transfer ratio (Q̇). KolbenFraktion ) on the piston 28. In certain configurations, the control 56 is arranged to have an upper surface (A p ) of piston 28 and continuously update the estimated temperature (T p) of piston 28 at each subsequent time step. The controller 56 can use this information to calculate a rejection fraction. Therefore, the real-time calculation of the heat fraction at piston 28 can also be based on the determined upper surface area of ​​piston 28 and / or the estimated temperature of piston 28 can be continuously updated at each subsequent time step. In various configurations, the controller 56 is set up to calculate the rejection fraction in real time based on the determined temperature of combustion 34, the determined average temperature of wall 16 of cylinder 14, the determined surface area of ​​wall 16 of cylinder 14, the determined upper surface area of ​​piston 28, and the estimated temperature of piston 28 at each subsequent time step. Therefore, the controller 56 can use equation (1) to calculate the rejection fraction as shown below: Rejection component=Ap(Tka¨mmen−Tp)Ap(Tka¨mmen−Tp)+Aw(Tka¨mmen−TWand) where: Rejection fraction = the heat fraction between the piston 28 and the wall 16 of the cylinder 14; T p = the estimated temperature of the piston 28 (in °C) (see Fig. 2); T kämmen = the recalculated temperature of the combustion 34 (in °C) (see Fig. 2); T Wand = the average temperature of wall 16 of cylinder 14 (in °C) (see Fig. 2); A w = the surface area of ​​the wall 16 of the cylinder 14 (in mm) 2 ), based on the time of combustion 34 (see Fig. 2); and A p = the upper surface of the piston 28 (in mm) 2 ) (see Fig. 2).

[0047] The surface (A wThe area (A) of the wall 16 of the cylinder 14 can be determined such that the area of ​​the wall 16 of the cylinder 14 and the exposed area of ​​a piston crown 28 can be determined based on the real-time position of the piston 28 with respect to the time of combustion 34. To determine the area (A w ) of the wall 16 of the cylinder 14, as discussed above in equation (1), the controller 56 can also determine data / information regarding a displacement of the piston 28 based on an angular position (θ) of the crankshaft 24 after top dead center, a radius (r) of the crankshaft 24, and a length (l) of the connecting rod 32. The controller 56 can use this data to determine the surface (A) in real time. w ) of the wall 16 of the cylinder 14 to be calculated based on the time of combustion 34. More precisely, determining the surface area (A w) the wall 16 of the cylinder 14 also includes calculating the displacement of the piston 28 in real time, based on the angular position of the crankshaft 24 after top dead center, the radius of the crankshaft 24 and the length of the connecting rod 32. Therefore, the displacement of the piston 28 can be calculated in real time based on the angular position of the crankshaft 24 after top dead center, the radius of the crankshaft 24 and the length of the connecting rod 32, using equation (2): s=l+r−x where: s = the displacement of the piston 28 (see Fig. 3); 1 = the length of the connecting rod 32 (see Fig. 3); r = the radius of the crankshaft 24 (see Fig. 3); and x = the distance between the piston 28 and a center point of the crankshaft 24, which is located on the longitudinal axis 26 (see Fig. 3).

[0048] The displacement of piston 28 from equation (2) can be used to determine the surface area (A w ) the wall 16 of the cylinder 14 using the equation (A w = (πr 2 + 2πrs) * 4), which is a simplified version of equation (3) below: Aw=[πr2+2πr(l+r−rdenn(θ)+l2−r2sin(θ)2)]∗4 where: A w = the surface area of ​​the wall 16 of the cylinder 14 (in mm2), relative to the time of combustion 34; r = the radius of the crankshaft 24 (see Fig. 3); l = the length of the connecting rod 32 (see Fig. 3); and θ = the angular position of the crankshaft 24 after top dead center at the time of combustion 34 (see Fig. 3).

[0049] In certain configurations, the angular position of the crankshaft 24 after top dead center is further defined as the angular position of the crankshaft 24 after the release of fifty percent of the heat of combustion. Therefore, θ in the above equation (3) can be replaced by CA50, which represents the angular position of the crankshaft 24 after the release of fifty percent of the heat of combustion (i.e., when fifty percent of the combustion is complete).

[0050] The controller 56 can use the information obtained from equations 1-3 above to determine the heat fraction at piston 28, which provides the estimated temperature of piston 28 used to control the various states. The estimated temperature of piston 28 can be used in the piston temperature model or any other suitable model or calculation, etc. Once the rejection fraction is determined, the controller 56 can then calculate the real-time heat fraction to piston 28. Therefore, the controller 56 is also configured to determine a total convection rate of the combustion gas heat. The total convection rate of the combustion gas heat occurs in cylinder 14. This data can be used to calculate the heat fraction to piston 28 in real time. Therefore, the real-time calculation of the heat fraction to piston 28 is also based on the determined total convection rate of the combustion gas heat.In certain configurations, the (real-time) calculated heat contribution to piston 28 can also include the controller 56, which is configured to multiply the rejection contribution by the total convection rate of the combusted gas heat. The real-time heat contribution (Q̇. KolbenFrαktion ) on piston 28 can be calculated using equation (4): Q˙PistonFaction=Q˙totalrej(Rejection Faction) where: Q̇ totalrej = the total heat convection rate of the combusted gas in kW; rejection fraction = equation (1); and Q̇ KolbenFraktion = the heat component to piston 28.

[0051] The controller 56 can use the real-time heat contribution to piston 28 to adjust various states of the engine 10, as described above, based on the estimated temperature of piston 28. An algorithm can implement the calculated real-time heat contribution to piston 28 into a physically based piston temperature model that captures the actual amount of heat energy going to piston 28. By using this algorithm, the actual temperature conditions of piston 28 are implemented instead of calibration tables that use a constant table to predict piston 28 temperature. The estimated temperature of piston 28 is continuously updated in the procedure 100 to continuously provide real-time data that allows for more accurate real-time control of the engine 10's state, thereby improving various operational characteristics of the moving platform.It should be noted that the order or sequence of carrying out procedure 100, as discussed above, serves only for illustration and other arrangements or sequences fall within the scope of the present teaching.

[0052] While the preferred embodiments and other configurations for carrying out the disclosure have been described in detail, those familiar with the field to which this disclosure relates will recognize various alternative patterns and configurations for carrying out the disclosure within the scope of the appended claims. Furthermore, the configurations shown in the figures or the features of the various configurations mentioned in this description are not necessarily to be understood as independent configurations. Rather, it is possible that each of the features described in one of the examples of a configuration can be combined with one or more other desired features from other configurations, leading to other configurations that are not described in words or by reference to the figures.Accordingly, such other configurations fall within the scope of the attached claims.

Claims

[1] A method (100) for providing a real-time calculation of the heat flow in an engine (10) comprising an engine block with a cylinder (14) and a wall surrounding the cylinder (14), wherein a piston is arranged in the cylinder (14) and is movable relative to the wall of the cylinder (14) in response to the timing of combustion in a combustion chamber within the cylinder (14), and the piston (28) is connected to a crankshaft via a connecting rod, the method comprising: Determining the temperature of the combustion inside the cylinder (14); Determining the average temperature of the cylinder wall; Determining the surface area of ​​the cylinder wall based on the time of combustion; Calculating in real time, via a controller, a heat component at the piston (28) based on the determined combustion temperature, the determined average temperature of the cylinder wall and the determined surface area of ​​the cylinder wall; and Controlling a state of the engine (10) based on an estimated temperature of the piston (28) derived from the real-time calculation of the heat content of the piston, wherein determining the surface area of ​​the cylinder wall further includes determining a displacement of the piston (28) based on an angular position of the crankshaft after top dead center, wherein the angular position is defined as the angular position of the crankshaft after releasing fifty percent of the heat of combustion (CA50). [2] The method (100) according to claim 1: furthermore, including determining an upper surface of the piston (28); and where the calculation of the heat component at the piston (28) in real time is also based on the determined upper surface of the piston (28). [3] The method (100) according to claim 2, wherein the calculation of the heat component on the piston (28) in real time further includes the continuous updating of the estimated temperature of the piston at each subsequent time step. [4] The method (100) according to claim 3: furthermore, comprehensively determining the overall convection rate of the combusted gas heat; and where the calculation of the heat contribution to the piston in real time is also based on the determined total convection rate of the combusted gas heat. [5] The method (100) according to claim 1, wherein controlling the engine state includes injecting fuel into the combustion chamber based on the estimated temperature of the piston as derived from the real-time calculation of the heat content of the piston (28). [6] The method (100) according to claim 1, wherein controlling the engine state includes controlling an air-fuel ratio of the combustion chamber based on the estimated temperature of the piston as derived from the real-time calculation of the heat content on the piston (28). [7] The method (100) according to claim 1, wherein controlling the engine state includes injecting oil into the cylinder around the piston (28) based on the estimated temperature of the piston as derived from the real-time calculation of the heat content of the piston. [8] The method (100) according to claim 1, wherein the calculation of the heat component on the piston (28) in real time further includes the continuous updating of the estimated temperature of the piston at each subsequent time step. [9] A motor system for a movable platform; the system includes: an engine (10) with an engine block having a cylinder (14) and a wall surrounding the cylinder; a crankshaft (24) which is supported on the engine block and rotatable relative to a longitudinal axis; a piston which is connected to the crankshaft (24) via a connecting rod, the piston being arranged in the cylinder (14) and being movable relative to the wall of the cylinder (14) in response to the timing of combustion in a combustion chamber inside the cylinder (14); and a control system that is set up: to determine the temperature of the combustion inside the cylinder (14); to determine an average temperature of the cylinder wall; to determine the surface area of ​​the cylinder wall based on the time of combustion; to calculate, via the control system in real time, a heat component at the piston based on the determined combustion temperature, the determined average temperature of the cylinder wall, and the determined surface area of ​​the cylinder wall; and to control a state of the engine (10) based on an estimated temperature of the piston (28) derived from the real-time calculation of the heat content of the piston, wherein determining the surface area of ​​the cylinder wall further includes determining a displacement of the piston (28) based on an angular position of the crankshaft after top dead center, wherein the angular position is defined as the angular position of the crankshaft after releasing fifty percent of the heat of combustion (CA50).

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