A piston, an internal combustion engine, an internal combustion engine control system, and an internal combustion engine control method

Abstract

The application discloses a piston, an internal combustion engine, an internal combustion engine control system and an internal combustion engine control method, relates to the technical field of optimal design of internal combustion engine pistons, and the piston comprises a piston body, an outer surface of a piston skirt of the piston body is processed with a bionic hole array, rows of the bionic hole array are staggered, and columns of the bionic hole array are staggered, wherein the bionic holes in odd-numbered rows are pits, the bionic holes in even-numbered rows are through holes, or the bionic holes in odd-numbered rows are through holes, and the bionic holes in even-numbered rows are pits, the bionic holes in the same row in the bionic hole array are of the same hole diameter, the hole diameter of the bionic holes gradually decreases along the axial direction of the piston skirt, and the hole diameter of the bionic holes gradually decreases from the top of the piston skirt to the bottom of the piston skirt, the row spacing gradually decreases, and the column spacing in the bionic hole array is the same. The bionic non-smooth structure is applied to the piston skirt of the internal combustion engine, so that the piston is optimally designed, the piston can be better optimally designed, and the performance of the piston is improved.

Description

Technical Field

[0001] This application relates to the field of internal combustion engine piston optimization design technology, and in particular to a piston, an internal combustion engine, an internal combustion engine control system, and an internal combustion engine control method. Background Technology

[0002] As the core of power machinery, the internal combustion engine's piston-cylinder liner system is one of the main friction pairs. The friction loss generated by this piston-cylinder liner system accounts for a large proportion of the total friction loss of the internal combustion engine. With the continuous improvement of energy conservation and emission reduction requirements, reducing the friction loss generated by the piston-cylinder liner system and extending the service life of the piston in the piston-cylinder liner system have become key directions for the technological upgrading of internal combustion engines. The piston is the core component of the internal combustion engine, so optimizing the design of the piston is crucial.

[0003] In related technologies, attempts have been made to apply biomimetic non-smooth structures to the piston skirt of internal combustion engines to optimize piston design. However, most of these designs use uniform aperture and uniformly arranged pits or through holes. Although these can reduce friction to some extent, using uniform aperture can reduce piston performance if the aperture design is unreasonable (too large aperture weakens stiffness, too small aperture affects drag reduction). Using uniform arrangement can create dead zones for stress dispersion and lubrication blind spots, making it impossible to effectively unload the concentrated stress at the oil return hole, which will reduce piston performance. At the same time, using a single aperture type such as pits or through holes makes it difficult to balance the dual requirements of lubrication storage and stress dispersion, which will reduce piston performance. Summary of the Invention

[0004] The purpose of this application is to provide a piston, an internal combustion engine, an internal combustion engine control system, and an internal combustion engine control method, which can better optimize the design of the piston and improve its performance.

[0005] To achieve the above objectives, this application provides the following solution.

[0006] In a first aspect, this application provides a piston, the piston comprising: a piston body, wherein a biomimetic hole array is machined on the outer surface of the piston skirt of the piston body; Define the axial direction of the piston skirt as the row arrangement direction and the radial direction of the piston skirt as the column arrangement direction. The rows of the bionic hole array are staggered and the columns of the bionic hole array are staggered. The bionic holes in the odd-numbered rows are pits and the bionic holes in the even-numbered rows are through holes, or the bionic holes in the odd-numbered rows are through holes and the bionic holes in the even-numbered rows are pits. In the bionic hole array, the bionic holes in the same row have the same diameter. Along the piston skirt axis, and from the top to the bottom of the piston skirt, the diameter of the bionic holes gradually decreases, and the row spacing gradually decreases. In the bionic hole array, the column spacing is the same.

[0007] Optionally, the biomimetic hole array is located in the effective lubrication area on the outer surface of the piston skirt.

[0008] Optionally, the aperture of the bionic hole ranges from 1mm to 3.5mm; the depth of the pit is 1mm.

[0009] Optionally, the bionic hole is processed using laser processing technology.

[0010] Secondly, this application provides an internal combustion engine, wherein the piston of the internal combustion engine adopts the aforementioned piston.

[0011] Thirdly, this application provides an internal combustion engine control system, which includes: a sensing and detection module, a control module, and an execution module, wherein the sensing and detection module and the execution module are both communicatively connected to the control module; The sensing and detection module is used to collect the state parameters of the piston of the internal combustion engine during operation; the internal combustion engine is the one described above, and the state parameters include the maximum stress of the piston skirt, the average temperature of the piston top, and the coefficient of friction between the piston and the cylinder liner. The control module is used to determine the optimal values ​​of the operating parameters based on the state parameters, and to issue control commands based on the optimal values ​​of the operating parameters; the operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume; The execution module is used to execute the control instructions to adjust the operating parameters so that the operating parameters take the optimal values.

[0012] Optionally, in determining the optimal values ​​of the operating parameters based on the state parameters, the control module is configured to: Based on the maximum stress of the piston skirt, a stress adaptive control algorithm is used to determine the target stress of the piston skirt, and based on the target stress of the piston skirt, a first value of the lubricating oil supply pressure is determined. Based on the friction coefficient between the piston and the cylinder liner, the piston lubricating oil supply amount is determined using a friction state feedback control algorithm, and a second value of the lubricating oil supply pressure is determined based on the piston lubricating oil supply amount. Based on the first and second values ​​of lubricating oil supply pressure, the range of ignition advance angle, and the range of intake air volume, multiple value combinations are determined. For each value combination, the internal combustion engine is controlled to operate according to the value combination to obtain the operating parameters under the value combination. Based on the operating parameters under the value combination, the objective function value under the value combination is calculated. The value combination with the smallest objective function value is selected as the optimal value combination. Based on the optimal value combination, the optimal values ​​of the operating parameters are determined. The value combination includes one value of lubricating oil supply pressure, one value of ignition advance angle, and one value of intake air volume.

[0013] Optionally, the formula for calculating the target stress of the piston skirt is: ; in, The target stress is the piston skirt. This represents the maximum stress on the piston skirt. This is the stress correction factor; This is the reference stress for the piston skirt. The formula for calculating the piston lubricating oil supply is: ; in, For piston lubricating oil supply; The coefficient of friction between the piston and the cylinder liner; The maximum permissible coefficient of friction; Reference supply amount of piston lubricating oil; The formula for calculating the objective function value is as follows: ; in, The objective function value; The first weighting coefficient; The coefficient of friction between the piston and cylinder liner under the given combination of values; This is the second weighting coefficient; This represents the maximum stress on the piston skirt under the given value combination. This is the third weighting coefficient; The piston temperature deviation under the given value combination is equal to the difference between the average piston top temperature and the reference temperature under the given value combination.

[0014] Optionally, the execution module includes a variable oil pressure valve, a variable ignition advance angle controller, and an electronic throttle valve, wherein the variable oil pressure valve, the variable ignition advance angle controller, and the electronic throttle valve are all communicatively connected to the control module; The variable oil pressure valve is used to execute the control command to adjust the lubricating oil supply pressure so that the lubricating oil supply pressure takes the optimal value. The variable ignition advance angle controller is used to execute the control command to adjust the ignition advance angle so that the ignition advance angle takes the optimal value of the ignition advance angle. The electronic throttle valve is used to execute the control command to adjust the intake air volume so that the intake air volume takes the optimal value.

[0015] Fourthly, this application provides an internal combustion engine control method, which operates based on the aforementioned internal combustion engine control system, the internal combustion engine control method comprising: Obtain the state parameters of the piston of the internal combustion engine during operation; the state parameters include the maximum stress of the piston skirt, the average temperature of the piston top, and the coefficient of friction between the piston and the cylinder liner; Based on the state parameters, the optimal values ​​of the operating parameters are determined, and control commands are issued based on the optimal values ​​of the operating parameters; the operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume; the execution module is used to execute the control commands to adjust the operating parameters so that the operating parameters take the optimal values.

[0016] According to the specific embodiments provided in this application, this application has the following technical effects.

[0017] This application provides a piston, an internal combustion engine, an internal combustion engine control system, and an internal combustion engine control method. It applies a biomimetic non-smooth structure to the piston skirt of the internal combustion engine to optimize piston design. The outer surface of the piston skirt of the piston body is machined with a biomimetic hole array. The rows and columns of the biomimetic hole array are staggered. The biomimetic holes store lubricating oil to form a stable oil film. Combined with the drag reduction effect brought by the staggered row and column arrangement, the friction loss between the piston and cylinder liner is significantly reduced. This avoids the dead zones and lubrication blind spots in column-direction stress dispersion that exist in uniform arrangement, thus solving the problem of reduced piston performance caused by uniform arrangement. In the biomimetic hole array, the odd-numbered rows of biomimetic holes are recesses, and the even-numbered rows are through holes, or vice versa. By combining two hole types, both stress dispersion and lubrication storage functions are considered. Through holes can more thoroughly unload concentrated stress, while recesses can effectively store lubricating oil and wear debris, improving lubrication stability. This can solve the problem of reduced piston performance caused by using only one hole type, either through holes or recesses. In the bionic hole array, the diameter of the bionic holes in the same row is the same. Along the piston skirt axis, from the top to the bottom of the piston skirt, the diameter of the bionic holes gradually decreases, and the row spacing gradually decreases. In the bionic hole array, the column spacing is the same, and the diameter of the bionic holes gradually decreases along the piston skirt axis from the top to the bottom. The larger diameter at the top is used to unload concentrated stress, and the smaller diameter at the bottom is used to ensure the rigidity of the piston skirt. This can solve the problem of reduced piston performance caused by using uniform hole diameter, thus allowing for better optimization of piston design and improved piston performance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a biomimetic aperture array provided in Embodiment 3 of this application.

[0020] Figure 2 This is a schematic diagram of the recess and through hole configuration provided in Embodiment 3 of this application.

[0021] Figure 3 This is a flowchart of an internal combustion engine control system provided in Embodiment 3 of this application.

[0022] Figure 4 This is a flowchart of an internal combustion engine control method provided in Embodiment 4 of this application.

[0023] Figure 5 This is a schematic diagram of the structure of a computer device provided in Embodiment 5 of this application.

[0024] Reference numerals: 1-Dimple; 2-Through hole. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Example 1 In the biological world, the yellow-margined water beetle (a large aquatic beetle of the family Dystomidae in the order Coleoptera) has evolved a non-smooth structure on its body surface – pits. This non-smooth structure can effectively reduce fluid resistance and solid friction during movement, enabling it to swim efficiently in water. Related technologies have attempted to apply biomimetic non-smooth structures to the piston skirt of internal combustion engines. However, most of the related designs use pits or through-hole structures with uniform aperture and uniform arrangement, without considering the thermal-structural coupling stress distribution characteristics of the piston skirt during actual operation. This makes it difficult to fully utilize the drag reduction and stress dispersion performance of the biomimetic structure, and problems such as large fluctuations in friction loss and unstable fatigue life still exist.

[0027] To address the above problems, this embodiment employs the following biomimetic structural design: (1) Selection of biomimetic prototype and extraction of structural parameters: The drag-reducing and wear-resistant pit structure on the body surface of the yellow-margined water beetle (i.e. the aforementioned non-smooth body surface structure) is used as the biomimetic prototype. The arrangement pattern and structural characteristics of the pits are determined by microscopic observation. The size characteristics of the piston skirt of the internal combustion engine are combined for adaptation and optimization. The basic design structural parameters of the biomimetic hole are determined. The aperture of the biomimetic hole is preferably 1mm~3.5mm and the pit depth is preferably 1mm.

[0028] (2) Gradient bionic hole array optimization: Through finite element thermal-structural coupling analysis (establishing a finite element model of the piston skirt, applying thermal boundary conditions and structural loads, and determining the thermal-structural coupling stress at each position of the piston skirt, which is an existing mature technology and will not be elaborated here), the stress distribution law of the piston skirt is obtained, and a gradient bionic hole array is designed based on the stress distribution law: the diameter of the bionic hole gradually decreases from the top to the bottom along the piston skirt axis. The large diameter at the top is used to unload concentrated stress, and the small diameter at the bottom is used to ensure the stiffness of the piston skirt. The row spacing gradually decreases from the top to the bottom along the piston skirt axis, which is matched with the stress distribution law. This can solve the problem of reduced piston performance caused by using uniform hole diameter. At the same time, the row and column bidirectional staggered arrangement avoids the column stress dispersion dead angle and lubrication blind area present in the uniform arrangement, which can solve the problem of reduced piston performance caused by using uniform arrangement.

[0029] (3) Hole type combination design: a composite hole type with alternating rows of recesses and through holes is adopted. By combining the two hole types, stress dispersion and lubrication storage functions are taken into account. Through holes can more thoroughly unload concentrated stress, while recesses can effectively store lubricating oil and wear debris, improve lubrication stability, and solve the problem of reduced piston performance caused by using a single hole type of recesses or through holes.

[0030] Based on the above biomimetic structural design, this embodiment provides a piston, which includes: a piston body, and a biomimetic hole array processed on the outer surface of the piston skirt of the piston body (the outer surface of the piston skirt is the outermost cylindrical surface of the piston skirt that directly faces the cylinder wall).

[0031] The piston skirt axis is defined as the row arrangement direction, and the rows of the bionic hole array are arranged sequentially along the piston skirt axis. The piston skirt radial direction is defined as the column arrangement direction, and the columns of the bionic hole array are arranged sequentially along the piston skirt radial direction. The piston skirt thickness direction is perpendicular to both the piston skirt axis and the piston skirt radial direction.

[0032] This embodiment utilizes the biomimetic structure of the yellow-margined water beetle to fabricate a biomimetic hole array on the outer surface of the piston skirt of the piston body in an internal combustion engine. The biomimetic hole array employs a bidirectional staggered arrangement of rows and columns, equivalent to a combined structure of staggered rows and synchronously staggered columns. Row staggering means that a biomimetic hole in the next row aligns with the middle of two biomimetic holes in the previous row; column staggering means that a biomimetic hole in the next column aligns with the middle of two biomimetic holes in the previous column. The hole shapes combine recesses and through holes in an alternating combination. Odd-numbered rows have recesses, and even-numbered rows have through holes, or vice versa. The recesses are shallow depressions, with bottoms that are mostly arc-shaped, conical, or flat. They are large in diameter, very shallow, and lack distinct vertical walls, resembling a shallow pit.

[0033] The biomimetic hole array adopts a gradient arrangement of hole diameter and row spacing. It is designed based on the stress distribution law obtained from the finite element thermal-structural coupling analysis of the piston skirt. The hole diameter and row spacing of the biomimetic holes in the stress concentration area are greater than those in the stress dispersion area. Therefore, the hole diameter gradient of the biomimetic holes is designed to match the stress distribution gradient of the piston skirt. The hole diameter of the biomimetic holes in the top stress concentration area is greater than that in the bottom stress dispersion area (area with higher stiffness requirements). The hole diameter of the biomimetic holes is set to decrease sequentially from top (top of piston skirt) to bottom (bottom of piston skirt). The row spacing gradient of the biomimetic holes is matched with the hole diameter gradient. The row spacing in the top stress concentration area is greater than that in the bottom stress dispersion area. The row spacing is set to decrease sequentially from top to bottom, while the column spacing remains fixed (the distance between two adjacent columns remains unchanged). At this point, in the bionic hole array, the bionic holes in the same row have the same diameter. The diameter of the bionic holes gradually decreases from top to bottom along the piston skirt axis. The row spacing also gradually decreases from top to bottom along the piston skirt axis. That is, along the piston skirt axis and from the top to the bottom of the piston skirt, the diameter of the bionic holes gradually decreases. In other words, the diameter of the bionic hole in the lower row of any two adjacent rows is smaller than the diameter of the bionic hole in the upper row. The row spacing gradually decreases. In the bionic hole array, the column spacing is the same and remains a fixed value.

[0034] Optionally, the bionic hole array is located within the effective lubrication area of ​​the outer surface of the piston skirt, covering this area. The effective lubrication area refers to the surface region between the piston skirt and the cylinder wall that forms a stable, load-bearing oil film and truly lubricates and reduces friction during normal piston operation. This area can be determined by the user based on experience. Limiting the machining area of ​​the bionic hole array to the effective lubrication area of ​​the outer surface of the piston skirt can further improve piston performance. Furthermore, the number of rows in the bionic hole array can be rationally set according to the dimensions of the piston skirt.

[0035] Optionally, the aperture of the bionic hole is preferably in the range of 1mm to 3.5mm, the depth of the bionic hole is strictly adapted to the thickness of the piston skirt, and the depth of the pit is preferably 1mm.

[0036] Optionally, the biomimetic hole array can be processed using laser processing technology. In this case, the biomimetic holes are processed using laser processing technology, resulting in smooth inner walls and burr-free edges. By using laser processing technology to process the biomimetic hole array, the smoothness of the inner walls and edge quality of the biomimetic holes can be guaranteed, avoiding any impact on the piston-cylinder liner fit clearance.

[0037] This embodiment applies a biomimetic non-smooth structure to the piston skirt of an internal combustion engine to optimize piston design. The outer surface of the piston skirt of the piston body is machined with a biomimetic hole array. The rows and columns of the biomimetic hole array are staggered. In the biomimetic hole array, the odd-numbered rows have recessed holes, and the even-numbered rows have through holes, or vice versa. The holes in the same row have the same diameter. Along the piston skirt axis, from the top to the bottom of the piston skirt, the hole diameter and row spacing gradually decrease. The column spacing is the same. This design solves the piston performance degradation problems caused by using uniform arrangement, a single hole type (recessed or through holes), and uniform hole diameter, thus allowing for better piston optimization and improved piston performance.

[0038] Example 2 This embodiment provides an internal combustion engine, wherein the piston of the internal combustion engine adopts the piston described in Embodiment 1.

[0039] Example 3 This embodiment provides an internal combustion engine control system, which includes a sensing module, a control module, and an execution module. The sensing module and the execution module are both communicatively connected to the control module.

[0040] The sensing and detection module is used to collect the state parameters of the piston of the internal combustion engine during operation. The internal combustion engine is the one described in Example 2. The state parameters collected by the sensing and detection module include the maximum stress of the piston skirt, the average temperature of the piston top, and the friction coefficient between the piston and the cylinder liner.

[0041] Meanwhile, the sensing and detection module can also be used to collect cylinder pressure, crankshaft torque, lubricating oil pressure, lubricating oil temperature and internal combustion engine speed in the internal combustion engine to determine the internal combustion engine operating conditions, which is convenient for subsequent determination of parameters such as piston skirt reference stress, piston lubricating oil reference supply and reference temperature based on the internal combustion engine operating conditions.

[0042] Specifically, the sensing and detection module is used to collect the piston's state parameters during operation, including the maximum stress on the piston skirt (directly detected by a stress sensor), the average temperature of the piston top (directly detected by a temperature sensor), the coefficient of friction between the piston and cylinder liner (indirectly detected by a sensor, which is a mature existing technology and will not be elaborated here), the cylinder pressure (directly detected by a cylinder pressure sensor), the crankshaft torque (directly detected by a strain sensor), the lubricating oil pressure (directly detected by a pressure sensor), the lubricating oil temperature (directly detected by a temperature sensor), and the internal combustion engine speed (directly detected by a crankshaft position sensor), providing data support for the control module's control decisions.

[0043] The control module is used to determine the optimal values ​​of operating parameters based on the status parameters, and to issue control commands based on the optimal values ​​of the operating parameters. The operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume.

[0044] The lack of dynamic control strategies adapted to biomimetic structures in related technologies, i.e., the lack of real-time control means, leads to poor adaptability of biomimetic structure performance to internal combustion engine operating conditions. It cannot adjust operating parameters according to changes in internal combustion engine operating conditions such as engine speed, resulting in insufficient utilization of the drag reduction and stress dispersion performance of biomimetic structures, and persistent problems such as large fluctuations in friction loss and unstable fatigue life. To address this issue, the control module processes the state parameters collected by the sensing module based on the control formula in the preset control mode, further determining the optimal values ​​of the operating parameters and issuing control commands based on these optimal values. Specifically, the control module integrates two core control modes: stress adaptive control (preventing local stress overload and stress concentration) and friction state feedback control (sensing whether the current friction is high or low and automatically adjusting the lubrication contact friction state). The preset control modes of the control module include stress adaptive control and friction state feedback control, both with corresponding control formulas. These formulas process the detected state parameters, calculating two alternative values ​​for the lubricating oil supply pressure in the operating parameters. Further, combined with a multi-objective optimization objective function, the optimal values ​​of the operating parameters are determined, and control commands are output.

[0045] At this point, in determining the optimal values ​​of the operating parameters based on the state parameters, the control module performs the following steps: (1) Based on the maximum stress of the piston skirt, the target stress of the piston skirt is determined by the stress adaptive control algorithm, and the first value of the lubricating oil supply pressure is determined based on the target stress of the piston skirt.

[0046] The formula for calculating the target stress in the piston skirt (i.e., the control formula in stress adaptive control) is as follows: ; in, The target stress for the piston skirt is the target stress value. This represents the maximum stress on the piston skirt, which is a real-time measured stress value. This is a stress correction factor, which is dynamically adjusted according to the internal combustion engine operating conditions. It can be determined by the user based on experience, according to the internal combustion engine operating conditions. This is the reference stress for the piston skirt, which is the reference stress value for safe piston operation. It can be determined by the user based on experience and the operating conditions of the internal combustion engine.

[0047] Based on the detected maximum stress in the piston skirt, the control module calculates the target stress in the piston skirt using the aforementioned control formula, and further calculates the target stress in the piston skirt according to the target stress. According to the formula (in, The reference pressure for supplying lubricating oil can be determined by the user based on experience, taking into account the operating conditions of the internal combustion engine. To adjust the coefficient (which can be determined by the user based on experience according to the internal combustion engine operating conditions), calculate and output the lubricating oil supply pressure. The first value of the lubricating oil supply pressure is obtained, which is an alternative value of the lubricating oil supply pressure. This enables adaptive and coordinated control of the piston skirt stress and the lubricating oil supply pressure. It can adjust the lubricating oil supply pressure so that the piston skirt stress is maintained within the optimal range and stress concentration is avoided.

[0048] (2) Based on the friction coefficient between the piston and the cylinder liner, the piston lubricating oil supply amount is determined by the friction state feedback control algorithm, and the second value of the lubricating oil supply pressure is determined based on the piston lubricating oil supply amount.

[0049] The formula for calculating the piston lubricating oil supply (i.e., the control formula in friction state feedback control) is as follows: ; in, This refers to the piston lubricating oil supply amount, which is the lubricating oil supply amount adjustment value; The friction coefficient between the piston and the cylinder liner is the real-time measured value of the friction coefficient. The maximum permissible coefficient of friction can be determined by the user based on experience, taking into account the operating conditions of the internal combustion engine. The reference supply amount of piston lubricating oil is a benchmark value for the lubricating oil supply, which can be determined by the user based on experience according to the operating conditions of the internal combustion engine.

[0050] Based on the detected friction coefficient between the piston and cylinder liner, the control module calculates the piston lubricating oil supply using the aforementioned control formula. In the internal combustion engine lubrication system, the lubricating oil supply is linearly and positively correlated with the lubricating oil supply pressure. , For the supply of lubricating oil, The coefficients are linear. To supply pressure to the lubricating oil, the control module further adjusts the lubricating oil supply based on the piston's oil volume. Increase the supply of piston lubricating oil As a lubricating oil supply According to the formula Determine the lubricating oil supply pressure A second value for the lubricating oil supply pressure is determined, which is an alternative value for the lubricating oil supply pressure. This enables coordinated control of the lubricating oil supply quantity and the lubricating oil supply pressure. It can dynamically adjust the lubricating oil supply quantity, specifically by dynamically adjusting the lubricating oil supply pressure, to ensure the formation of a stable oil film within the bionic hole and reduce friction loss.

[0051] (3) Based on the first and second values ​​of lubricating oil supply pressure, the range of ignition advance angle and the range of intake air volume, multiple value combinations are determined. For each value combination, the internal combustion engine is controlled to operate according to the value combination to obtain the operating parameters under the value combination. Based on the operating parameters under the value combination, the objective function value under the value combination is calculated. The value combination with the smallest objective function value is selected as the optimal value combination. Based on the optimal value combination, the optimal value of the operating parameters is determined. The value combination includes one value of lubricating oil supply pressure, one value of ignition advance angle and one value of intake air volume.

[0052] This embodiment designs a multi-objective optimization objective function. Based on the maximum stress of the piston skirt, the friction coefficient between the piston and cylinder liner, and the piston temperature deviation, it seeks optimization among the first and second values ​​of the lubricating oil supply pressure, the range of the ignition advance angle (which can be customized by the user), and the range of the intake air volume (which can be customized by the user) to determine the optimal values ​​of the lubricating oil supply pressure, the ignition advance angle, and the intake air volume, thereby obtaining the optimal values ​​of the operating parameters.

[0053] The first and second values ​​of the lubricating oil supply pressure are two values ​​of the lubricating oil supply pressure. Multiple values ​​of the ignition advance angle are randomly selected from the range of values ​​of the ignition advance angle, and multiple values ​​of the intake air volume are randomly selected from the range of values ​​of the intake air volume. The two values ​​of the lubricating oil supply pressure, the multiple values ​​of the ignition advance angle, and the multiple values ​​of the intake air volume are randomly combined to obtain multiple value combinations. For each value combination, the internal combustion engine is controlled to operate according to the value combination, and the operating parameters under the value combination are collected by the sensor detection module.

[0054] The control module has a built-in multi-objective optimization objective function (i.e., the formula for calculating the objective function value) for parameter optimization: ; in, The objective function value; The first weighting coefficient is a preset weighting coefficient based on the type of internal combustion engine. The friction coefficient between the piston and cylinder liner under the given value combination is obtained by the sensing module. This is the second weighting coefficient, which is a preset weighting coefficient based on the type of internal combustion engine; The maximum stress on the piston skirt under the given value combination is obtained by the sensing module. This is the third weighting coefficient, which is a preset weighting coefficient based on the type of internal combustion engine; The piston temperature deviation under the given value combination is the deviation between the average piston top temperature and the reference temperature under the given value combination. It is equal to the difference between the average piston top temperature and the reference temperature under the given value combination. Specifically, the piston temperature deviation under the given value combination is obtained by calculating the difference between the average piston top temperature and the reference temperature under the given value combination. The average piston top temperature under the given value combination is acquired by the sensing and detection module.

[0055] Multi-objective synergistic optimization is achieved through the aforementioned multi-objective optimization objective function. Specifically, this multi-objective optimization objective function achieves synergistic optimization of friction loss, stress concentration, and temperature control. For each value combination, based on the operating parameters under the value combination, the objective function value under the aforementioned multi-objective optimization objective function is calculated. The value combination with the smallest objective function value is selected as the optimal value combination. Based on the optimal value combination, the optimal values ​​of the operating parameters are determined. That is, one value of lubricating oil supply pressure, one value of ignition advance angle, and one value of intake air volume in the optimal value combination are respectively taken as the optimal values ​​of lubricating oil supply pressure, ignition advance angle, and intake air volume, thus determining the optimal values ​​of the operating parameters.

[0056] Based on this, this embodiment can optimize the first and second values ​​of lubricating oil supply pressure, the range of values ​​for ignition advance angle and intake air volume to determine the optimal values ​​of lubricating oil supply pressure, ignition advance angle and intake air volume that minimize the objective function value, thereby obtaining the optimal values ​​of operating parameters.

[0057] After obtaining the optimal values ​​of the operating parameters based on the calculation results of the multi-objective optimization objective function, the control module further issues (or sends down) control commands based on the optimal values ​​of the operating parameters. These control commands are used to adjust the three operating parameters of lubricating oil supply pressure, ignition advance angle and intake air volume in real time, so that the friction coefficient, maximum stress and piston temperature deviation reach the optimal at the same time, realizing the dynamic matching between the bionic structure and the internal combustion engine operating conditions.

[0058] The execution module is used to execute control instructions to adjust the operating parameters so that the operating parameters take the optimal values.

[0059] Specifically, the execution module is used to adjust operating parameters in response to control commands. The execution module includes a variable oil pressure valve, a variable ignition advance angle controller, and an electronic throttle. The variable oil pressure valve, variable ignition advance angle controller, and electronic throttle are all connected to the control module and are used to adjust the lubricating oil supply pressure, ignition advance angle, and intake air volume in response to control commands. The variable oil pressure valve adjusts the lubricating oil supply pressure, the variable ignition advance angle controller adjusts the ignition advance angle, and the electronic throttle adjusts the intake air volume to achieve dynamic optimization of operating parameters.

[0060] A variable oil pressure valve is used to execute control commands to adjust the lubricating oil supply pressure so that the lubricating oil supply pressure is at its optimal value.

[0061] The variable ignition advance angle controller is used to execute control commands to adjust the ignition advance angle so that the ignition advance angle is the optimal value.

[0062] The electronic throttle is used to execute control commands to adjust the intake air volume so that the intake air volume is at its optimal value.

[0063] The existing technologies do not consider the thermal-structural coupling stress distribution characteristics of the piston skirt during actual operation and lack dynamic control strategies adapted to biomimetic structures. In other words, the lack of real-time control means leads to poor adaptability of biomimetic structure performance to internal combustion engine operating conditions. It is impossible to adjust operating parameters according to changes in internal combustion engine operating conditions such as engine speed, resulting in the inability to fully utilize the drag reduction and stress dispersion performance of biomimetic structures. Problems such as large fluctuations in friction loss and unstable fatigue life still exist. There is an urgent need for a biomimetic structure design that combines staggered arrangement, gradient aperture and row spacing, and pit and through hole combination, and combines it with an adaptive control system (i.e., the aforementioned internal combustion engine control system) to achieve synergistic optimization of drag reduction, wear resistance, stress dispersion, and dynamic matching with internal combustion engine operating conditions.

[0064] Based on this, and addressing the technical shortcomings of the biomimetic structure design of the piston skirt in internal combustion engines, such as the lack of matched stress distribution and collaborative control strategy, this embodiment provides an internal combustion engine piston skirt, internal combustion engine, and control system based on the biomimetic structure of the body surface of the yellow-margined water beetle. By simulating the non-smooth characteristics of the pits on the body surface of the yellow-margined water beetle, and combining the results of finite element thermal-structural coupling analysis of the piston skirt, a gradient biomimetic hole array is designed, and an adaptive control system is added. The biomimetic structure designed based on the stress distribution obtained from the finite element thermal-structural coupling analysis of the piston skirt is matched and coordinated with three operating parameters—lubricating oil supply pressure, ignition advance angle, and intake air volume—in real time to achieve collaborative control. Through stress adaptive control, friction state feedback control, and multi-objective optimization, the friction coefficient, maximum stress, and piston temperature deviation of the piston skirt are optimized in a coordinated manner, allowing the biomimetic structure to fully exert its drag reduction, wear resistance, and heat dissipation functions under all operating conditions.

[0065] The beneficial effects of this embodiment are as follows: (1) Significantly reduce friction loss: The bionic hole array forms a stable oil film by storing lubricating oil. Combined with the drag reduction effect of the staggered arrangement and the friction state feedback control, it greatly reduces the friction loss between the piston and the cylinder liner. (2) Effectively alleviate stress concentration: The gradient aperture and row spacing design match the stress distribution of the piston skirt. The through hole structure can transfer the concentrated stress at the oil return hole. Combined with stress adaptive control, the maximum stress at the piston top is kept within a safe range, thus extending fatigue life. (3) Improve the adaptability of working conditions: The control system collects state parameters in real time and dynamically adjusts operating parameters such as lubricating oil supply pressure, ignition advance angle, and intake volume based on the control formula, so that the performance of the bionic structure matches the working conditions of the internal combustion engine such as the speed of the internal combustion engine in real time, and ensures stable performance under all working conditions. (4) Balancing rigidity and reliability: The small bottom aperture and small row spacing design ensure the structural rigidity of the piston skirt, avoids excessive deformation of the piston skirt due to bionic hole processing, and adapts to the high-speed operation requirements of internal combustion engines. (5) Strong processing compatibility: Laser processing technology is compatible with existing piston production lines, and the internal combustion engine control system can be upgraded through ECU (Electronic Control Unit) software without major equipment modifications, and production costs are controllable; (6) Performance optimization: The coordinated control significantly reduces the frictional loss generated by the piston-cylinder liner system, reduces energy loss, and increases the power of the working gas in the cylinder; at the same time, the piston heat dissipation efficiency is improved through the synergistic effect of biomimetic hole heat dissipation and oil film heat dissipation, so as to achieve simultaneous improvement in power and reliability.

[0066] This embodiment provides an internal combustion engine piston and its control system based on the biomimetic structure of the yellow-margined water beetle's body surface. Using the pitted structure on the yellow-margined water beetle's body surface, which has drag-reducing and wear-resistant functions, as a biomimetic prototype, and combining the thermal-structural coupling stress distribution characteristics of the internal combustion engine piston skirt, a biomimetic array of holes with gradient variations in aperture and row spacing is designed. A combination of pits and through holes is adopted, alternating row by row and column by column. An adaptive control system is also added, which monitors the piston's state parameters during operation and dynamically adjusts the operating parameters based on control formulas. This achieves real-time matching between the biomimetic structure performance and the internal combustion engine's operating conditions, solving the technical problems of high frictional loss, stress concentration, short fatigue life, and lack of coordinated control in the piston skirt. It can significantly reduce piston wear, improve the power of the working gas in the cylinder, and increase piston heat dissipation efficiency. It is suitable for performance optimization of various internal combustion engine pistons, such as those in gasoline engines and diesel engines.

[0067] The following is a detailed explanation with specific examples.

[0068] Example: A biomimetic plug skirt adapted for conventional four-stroke internal combustion engines and its control process. The biomimetic perforation array design of the piston skirt, such as Figure 1 As shown, it is compatible with conventional four-stroke internal combustion engines. The piston skirt height is adapted to the cylinder bore size, and the effective lubrication area covers the main friction areas of the piston skirt. The biomimetic perforation array has a gradually decreasing diameter and row spacing from top to bottom, arranged in an alternating row and column pattern. The through-hole recesses are arranged as follows... Figure 2 As shown, through holes 2 are set in odd-numbered rows, and recesses 1 are set in even-numbered rows. The depth of the recesses is adapted to the thickness of the piston skirt.

[0069] When controlling the internal combustion engine piston based on the aforementioned piston skirt, the sensing module collects real-time state parameters such as the maximum stress of the piston skirt, the average temperature of the piston top, the friction coefficient between the piston and the cylinder liner, the cylinder pressure, and the internal combustion engine speed. The control module presets three weighting coefficients. , , Piston skirt reference stress Maximum permissible coefficient of friction Piston lubricant reference supply Based on the state parameters, the optimal values ​​of the operating parameters are determined, and control commands are further issued. The execution module includes a variable oil pressure valve, a variable ignition advance angle controller, and an electronic throttle. The execution module responds to the control commands to adjust the operating parameters.

[0070] Control process such as Figure 3 As shown, it includes the following stages: (1) Start-up phase: Start the internal combustion engine, initialize the control module, run the execution module according to the reference parameters, output the lubricating oil supply reference pressure from the variable oil pressure valve, set the lubricating oil supply pressure to the reference value, set the ignition advance angle of the variable ignition advance angle controller to the reference value, and maintain the reference opening of the electronic throttle valve to set the intake air volume to the reference value. (2) Operation phase: The sensing and detection module collects the status parameters at fixed intervals, and the control module calculates two alternative values ​​for the lubricating oil supply pressure through stress adaptive control and friction state feedback control; (3) Adjustment stage: Stress adaptive control and friction state feedback control generate two alternative values ​​for lubricating oil supply pressure for stress optimization and friction optimization, respectively. The multi-objective optimization objective function takes friction coefficient, maximum stress and piston temperature deviation as optimization objectives. It seeks optimization in the two alternative values ​​of lubricating oil supply pressure, the range of ignition advance angle and the range of intake air volume to perform multi-objective optimization and obtain the optimal values ​​of the operating parameters that satisfy the global optimum. Furthermore, based on the optimal values ​​of the operating parameters, the control command is output to the execution module. The execution module responds to the control command and coordinates the adjustment of lubricating oil supply pressure, ignition advance angle and intake air volume. (4) Stable phase: continuous cycle operation phase and adjustment phase, ensuring that the piston maintains the optimal operating state under all working conditions until the internal combustion engine stops, that is, to determine whether the internal combustion engine stops. If yes, the control process ends; otherwise, the continuous cycle operation phase and adjustment phase continue.

[0071] Example 4 This embodiment provides an internal combustion engine control method, which operates based on the internal combustion engine control system described in Embodiment 3, such as... Figure 4 As shown, the internal combustion engine control method includes: S1, Obtain the state parameters of the piston of the internal combustion engine during operation; the state parameters include the maximum stress of the piston skirt, the average temperature of the piston top, and the coefficient of friction between the piston and the cylinder liner; S2, based on the state parameters, determine the optimal values ​​of the operating parameters, and issue control commands based on the optimal values ​​of the operating parameters; the operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume; the execution module is used to execute the control commands to adjust the operating parameters so that the operating parameters take the optimal values ​​of the operating parameters.

[0072] Example 5 In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, equivalent to the control module in embodiment 3, and its internal structure diagram may be as follows. Figure 5 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements an internal combustion engine control method.

[0073] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0074] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the internal combustion engine control method of embodiment 4.

[0075] Example 6 In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the internal combustion engine control method of embodiment 4.

[0076] Example 7 In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the internal combustion engine control method of embodiment 4.

[0077] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, use and processing of the relevant data are carried out in compliance with the relevant data protection laws and policies of the country where the location is located, and with the authorization granted by the owner of the corresponding device.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A piston, characterized in that, The piston includes: a piston body, wherein a biomimetic hole array is machined on the outer surface of the piston skirt of the piston body; Define the axial direction of the piston skirt as the row arrangement direction and the radial direction of the piston skirt as the column arrangement direction. The rows of the bionic hole array are staggered and the columns of the bionic hole array are staggered. The bionic holes in the odd-numbered rows are pits and the bionic holes in the even-numbered rows are through holes, or the bionic holes in the odd-numbered rows are through holes and the bionic holes in the even-numbered rows are pits. In the bionic hole array, the bionic holes in the same row have the same diameter. Along the piston skirt axis, and from the top to the bottom of the piston skirt, the diameter of the bionic holes gradually decreases, and the row spacing gradually decreases. In the bionic hole array, the column spacing is the same.

2. The piston according to claim 1, characterized in that, The biomimetic aperture array is located in the effective lubrication area on the outer surface of the piston skirt.

3. The piston according to claim 1, characterized in that, The diameter of the biomimetic hole ranges from 1mm to 3.5mm; the depth of the pit is 1mm.

4. The piston according to claim 1, characterized in that, The biomimetic hole is processed using laser processing technology.

5. An internal combustion engine, characterized in that, The piston of the internal combustion engine is the piston according to any one of claims 1-4.

6. An internal combustion engine control system, characterized in that, The internal combustion engine control system includes: a sensing module, a control module, and an execution module, wherein the sensing module and the execution module are both communicatively connected to the control module. The sensing and detection module is used to collect the state parameters of the piston of the internal combustion engine during operation; the internal combustion engine is the internal combustion engine of claim 5, and the state parameters include the maximum stress of the piston skirt, the average temperature of the piston top, and the coefficient of friction between the piston and the cylinder liner; The control module is used to determine the optimal values ​​of the operating parameters based on the state parameters, and to issue control commands based on the optimal values ​​of the operating parameters; the operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume; The execution module is used to execute the control instructions to adjust the operating parameters so that the operating parameters take the optimal values.

7. The internal combustion engine control system according to claim 6, characterized in that, In determining the optimal values ​​of the operating parameters based on the state parameters, the control module is used to: Based on the maximum stress of the piston skirt, a stress adaptive control algorithm is used to determine the target stress of the piston skirt, and based on the target stress of the piston skirt, a first value of the lubricating oil supply pressure is determined. Based on the friction coefficient between the piston and the cylinder liner, the piston lubricating oil supply amount is determined using a friction state feedback control algorithm, and a second value of the lubricating oil supply pressure is determined based on the piston lubricating oil supply amount. Based on the first and second values ​​of lubricating oil supply pressure, the range of ignition advance angle, and the range of intake air volume, multiple value combinations are determined. For each value combination, the internal combustion engine is controlled to operate according to the value combination to obtain the operating parameters under the value combination. Based on the operating parameters under the value combination, the objective function value under the value combination is calculated. The value combination with the smallest objective function value is selected as the optimal value combination. Based on the optimal value combination, the optimal values ​​of the operating parameters are determined. The value combination includes one value of lubricating oil supply pressure, one value of ignition advance angle, and one value of intake air volume.

8. The internal combustion engine control system according to claim 7, characterized in that, The formula for calculating the target stress of the piston skirt is: ； in, The target stress is the piston skirt. This represents the maximum stress on the piston skirt. This is the stress correction factor; This is the reference stress for the piston skirt. The formula for calculating the piston lubricating oil supply is: ； in, For piston lubricating oil supply; The coefficient of friction between the piston and the cylinder liner; The maximum permissible coefficient of friction; Reference supply amount of piston lubricating oil; The formula for calculating the objective function value is as follows: ； in, The objective function value; The first weighting coefficient; The coefficient of friction between the piston and cylinder liner under the given combination of values; This is the second weighting coefficient; This represents the maximum stress on the piston skirt under the given value combination. This is the third weighting coefficient; The piston temperature deviation under the given value combination is equal to the difference between the average piston top temperature and the reference temperature under the given value combination.

9. The internal combustion engine control system according to claim 6, characterized in that, The execution module includes a variable oil pressure valve, a variable ignition advance angle controller, and an electronic throttle valve. The variable oil pressure valve, the variable ignition advance angle controller, and the electronic throttle valve are all communicatively connected to the control module. The variable oil pressure valve is used to execute the control command to adjust the lubricating oil supply pressure so that the lubricating oil supply pressure takes the optimal value. The variable ignition advance angle controller is used to execute the control command to adjust the ignition advance angle so that the ignition advance angle takes the optimal value of the ignition advance angle. The electronic throttle valve is used to execute the control command to adjust the intake air volume so that the intake air volume takes the optimal value.

10. An internal combustion engine control method, operating based on the internal combustion engine control system according to any one of claims 6-9, characterized in that, The internal combustion engine control method includes: Obtain the state parameters of the piston of the internal combustion engine during operation; the state parameters include the maximum stress of the piston skirt, the average temperature of the piston top, and the coefficient of friction between the piston and the cylinder liner; Based on the state parameters, the optimal values ​​of the operating parameters are determined, and control commands are issued based on the optimal values ​​of the operating parameters; the operating parameters include lubricating oil supply pressure, ignition advance angle, and intake air volume; the execution module is used to execute the control commands to adjust the operating parameters so that the operating parameters take the optimal values.

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