Engine control method and related device

Abstract

This invention discloses an engine control method and related apparatus. When the engine enters dynamic VVT, the method acquires the current engine load parameters, current engine power parameters, and the current ambient pressure value of the engine's operating environment. Based on the current engine power parameters and ambient pressure value, it determines the threshold value for exiting dynamic VVT that satisfies the current engine operating conditions. When the current engine load parameters and the threshold value for exiting dynamic VVT meet the exit conditions, the method controls the engine to exit dynamic VVT. This application comprehensively considers the engine power parameters and the ambient pressure value of the engine's operating environment when determining the exit conditions for dynamic VVT, thereby ensuring that the exit conditions meet the engine's operating environment and power requirements. This effectively avoids frequent entry and exit of dynamic VVT in high-altitude areas where the engine requires higher torque.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, and more specifically, to an engine control method and related apparatus. Background Technology

[0002] Dynamic VVT (Variable Valve Timing) is a technology that has been gradually applied to vehicles in recent years. When the engine needs power, dynamic VVT is activated to meet that demand. To balance engine power and fuel economy, dynamic VVT is currently only used when the engine has a power requirement (e.g., when the engine needs high torque), and it deactivates and returns to normal VVT once the power requirement is met.

[0003] When a vehicle is driving at high altitudes and the engine enters dynamic VVT, it will exit dynamic VVT when the engine meets the exit conditions. Due to the operating conditions of the vehicle, the engine's charging efficiency will be low, and it needs to boost pressure to reach the target average indicated pressure. At this time, the actual average indicated pressure of the engine after exiting dynamic VVT will quickly fall below the target average indicated pressure, causing the engine to meet the conditions for entering dynamic VVT again and re-enter dynamic VVT. This cycle repeats, resulting in the engine frequently entering and exiting dynamic VVT, causing large fluctuations in vehicle torque and causing vehicle jerking problems. Summary of the Invention

[0004] In view of this, the present invention discloses an engine control method and related device to solve the problem of vehicle jerking caused by large fluctuations in vehicle torque due to frequent engine VVT.

[0005] An engine control method, comprising:

[0006] When the engine enters dynamic VVT, acquire the current engine load parameters, current engine power parameters, and the current environmental pressure value of the vehicle.

[0007] Based on the current engine power parameters and the current ambient pressure value, determine the critical value for exiting dynamic VVT that meets the current engine operating conditions;

[0008] If the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions, the engine is controlled to exit the dynamic VVT.

[0009] Optionally, determining the critical value for exiting dynamic VVT based on the current engine power parameters and the current ambient pressure value includes:

[0010] From the established correspondence between engine speed, ambient pressure value, and engine average indicated pressure threshold, determine the engine target average indicated pressure threshold corresponding to the current engine speed and the current ambient pressure value, wherein the current engine power parameters include: the current engine speed;

[0011] From the established correspondence between engine speed, engine target average indicated pressure, and average indicated pressure difference, the target average indicated pressure difference corresponding to the current engine speed and the current engine target average indicated pressure is determined, wherein the current engine load parameter includes: the current engine target average indicated pressure;

[0012] The target average indicated pressure threshold and the difference between the target average indicated pressure are determined as the exit threshold for dynamic VVT.

[0013] Optionally, the process for determining the engine's average indicated pressure threshold includes:

[0014] Turn off the engine's dynamic VVT function;

[0015] When the vehicle is running on the test road, for each set environmental pressure value, the engine speed is gradually increased from the lower limit of the engine speed according to different torque requirements to obtain the actual average indicated pressure of the engine under different engine target average indicated pressures at the set environmental pressure value, and the actual average indicated pressure of the engine is used as the average indicated pressure test value.

[0016] The engine average indicated pressure threshold is determined based on the average indicated pressure test value and the set pressure error range.

[0017] Optionally, determining the engine average indicated pressure threshold based on the average indicated pressure test value and the set pressure error range includes:

[0018] Determine whether the set environmental pressure value is less than the environmental pressure threshold value, wherein the environmental pressure threshold value is used to divide high-altitude environment and low-altitude environment;

[0019] If the set environmental pressure value is less than the environmental pressure threshold value, it is determined that the vehicle is operating in the high-altitude environment.

[0020] The difference between the average indicated pressure test value and the first pressure error amplitude is determined as the engine average indicated pressure threshold.

[0021] The set pressure error range includes: the first pressure error range.

[0022] Optionally, it also includes:

[0023] If the set environmental pressure value is not less than the environmental pressure threshold value, it is determined that the vehicle is operating in the low-altitude environment.

[0024] The sum of the average indicated pressure test value and the second pressure error amplitude is determined as the engine average indicated pressure threshold.

[0025] The set pressure error range includes the second pressure error range.

[0026] Optionally, the process of determining the average indicated pressure difference includes:

[0027] With the vehicle running on the test road, for each set engine target average indicated pressure, the engine speed is gradually accelerated from the lower limit of the engine speed according to different torque requirements.

[0028] For each set engine target average indicated pressure and each engine speed, the average indicated pressure difference is determined when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold.

[0029] Optionally, controlling the engine to exit the dynamic VVT when the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions includes:

[0030] When the difference between the current engine target average indicated pressure and the current engine actual average indicated pressure is less than the target average indicated pressure difference, and the current engine target average indicated pressure is less than the engine target average indicated pressure threshold, the current engine load parameter is determined to meet the exit dynamic VVT critical value.

[0031] Control the engine to disengage from the dynamic VVT;

[0032] The current engine load parameters include: the current engine target average indicated pressure and the current engine actual average indicated pressure;

[0033] The threshold for exiting dynamic VVT includes: the target average indicated pressure difference and the engine target average indicated pressure threshold.

[0034] Optionally, the process of the engine entering the dynamic VVT includes:

[0035] Obtain the current operating condition information of the engine;

[0036] If the current operating condition information meets the conditions for entering dynamic VVT, control the engine to enter dynamic VVT;

[0037] The current operating condition information includes: engine target average indicated pressure, engine actual average indicated pressure, throttle pedal opening, target air-fuel ratio, and engine speed.

[0038] An engine control device, comprising:

[0039] The acquisition unit is used to acquire the current engine load parameters, current engine power parameters, and the current environmental pressure value of the vehicle when the engine enters dynamic VVT.

[0040] The critical value determination unit is used to determine the critical value for exiting dynamic VVT that meets the current engine operating conditions based on the current engine power parameters and the current ambient pressure value.

[0041] The exit control unit is used to control the engine to exit the dynamic VVT when the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions.

[0042] A vehicle includes an engine controller, the engine controller including a memory and a processor;

[0043] The memory is used to store at least one instruction;

[0044] The processor is used to execute the at least one instruction to implement the engine control method described above.

[0045] As can be seen from the above technical solution, this invention discloses an engine control method and related device. When the engine enters dynamic VVT, the current engine load parameters, current engine power parameters, and the current environmental pressure value of the engine are obtained. Based on the current engine power parameters and the current environmental pressure value, a threshold value for exiting dynamic VVT that meets the current engine operating conditions is determined. When the current engine load parameters and the threshold value for exiting dynamic VVT meet the exit conditions, the engine is controlled to exit dynamic VVT. This application comprehensively considers the engine power parameters and the environmental pressure value of the engine operation when determining the exit conditions for dynamic VVT, thereby ensuring that the exit conditions for dynamic VVT meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid the frequent entry and exit of dynamic VVT when the engine requires high torque in high-altitude areas, that is, effectively avoid the frequent interruption of power output when the engine has high power demand, thus solving the problem of vehicle jerking caused by large fluctuations in vehicle torque. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the published drawings without creative effort.

[0047] Figure 1 This is a flowchart of an engine control method disclosed in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of an engine control device disclosed in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present invention. Detailed Implementation

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] This invention discloses an engine control method and related apparatus. When the engine enters dynamic VVT, the method acquires the current engine load parameters, current engine power parameters, and the current ambient pressure value where the engine is operating. Based on the current engine power parameters and the current ambient pressure value, it determines the threshold value for exiting dynamic VVT that meets the current engine operating conditions. When the current engine load parameters and the threshold value for exiting dynamic VVT meet the exit conditions, the method controls the engine to exit dynamic VVT. This application comprehensively considers the engine power parameters and the ambient pressure value where the engine is operating when determining the exit conditions, thus ensuring that the exit conditions meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid frequent entry and exit of dynamic VVT when the engine requires high torque in high-altitude areas, effectively preventing frequent interruptions in engine power output during periods of high power demand. This solves the problem of vehicle jerking caused by large fluctuations in vehicle torque.

[0052] See Figure 1 The present invention discloses a flowchart of an engine control method, which is applied to an engine controller and may include:

[0053] Step S101: When the engine enters dynamic VVT, obtain the current engine load parameters, the current engine power parameters, and the current environmental pressure value of the vehicle.

[0054] Preferably, the engine in this application can be a Miller cycle engine.

[0055] Dynamic VVT (Variable Valve Timing) is a significant innovation in modern engine technology. It intelligently controls the phase of the engine camshaft, allowing the valve opening and closing times to dynamically adjust with changes in engine speed, thereby optimizing engine performance.

[0056] The current engine load parameters in this application may include: engine target average indicated pressure, engine actual average indicated pressure, target intake pressure, required intake pressure, engine required torque, etc.

[0057] Mean Indicated Pressure (MIP) is the indicated work done per unit cylinder volume in one cycle of an engine, and it is an important indicator for measuring the actual cyclic power performance of an engine. MIP is not an actual force, but rather a ratio of work to volume. It reflects the utilization rate of the engine's cylinder working volume, that is, the ratio of the average work done by the working fluid on the piston within the cylinder to the cylinder's working volume. A higher MIP indicates a better engine working cycle and a higher utilization rate of the cylinder working volume.

[0058] The actual average indicated pressure of the engine refers to the actual average indicated pressure obtained during the actual operation of the engine.

[0059] Engine target mean indicated pressure refers to the engine's expected mean indicated pressure.

[0060] In practical applications, the process of determining the target mean indicated pressure of an engine may include:

[0061] (1) When it is a hybrid vehicle, the target average indicated pressure of the engine is obtained based on the engine's required torque.

[0062] The specific process of obtaining the target average indicated pressure of the engine based on the engine's required torque can be found in existing solutions and will not be repeated here.

[0063] (2) When it is a fuel vehicle, first determine the corresponding engine torque demand based on the accelerator pedal opening, and then obtain the engine target average indicated pressure based on the engine torque demand.

[0064] The current engine power parameters in this application include, but are not limited to, engine speed.

[0065] In this application, when the engine enters dynamic VVT due to power demand, the engine controller will acquire the engine load parameters, engine power parameters, and environmental pressure values ​​at various times in real time.

[0066] In practical applications, the current ambient pressure value at which the engine is operating can be used to determine whether the environment is at high or low altitude.

[0067] Step S102: Based on the current engine power parameters and the current ambient pressure value, determine the critical value for exiting dynamic VVT that meets the current engine operating conditions.

[0068] This application determines the critical value for exiting dynamic VVT based on real-time engine power parameters and the ambient pressure value under which the engine operates. That is, the critical value for exiting dynamic VVT differs for different engine power parameters and ambient pressure values ​​in this application.

[0069] Step S103: If the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions, control the engine to exit the dynamic VVT.

[0070] It should be noted that the threshold for exiting dynamic VVT includes multiple thresholds, and the thresholds vary depending on the engine load parameters.

[0071] In summary, this application discloses an engine control method that, when the engine enters dynamic VVT, acquires the current engine load parameters, current engine power parameters, and the current ambient pressure value where the engine is operating. Based on the current engine power parameters and the current ambient pressure value, it determines the threshold value for exiting dynamic VVT that satisfies the current engine operating conditions. When the current engine load parameters and the threshold value for exiting dynamic VVT meet the exit conditions, the engine is controlled to exit dynamic VVT. This application comprehensively considers the engine power parameters and the ambient pressure value where the engine is operating when determining the exit conditions, thus ensuring that the exit conditions meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid frequent entry and exit of dynamic VVT when the engine requires high torque in high-altitude areas, effectively preventing frequent interruptions in engine power output during periods of high power demand. This solves the problem of vehicle jerking caused by large fluctuations in vehicle torque.

[0072] In one embodiment, step S102 may specifically include:

[0073] (1) Determine the target average indicated pressure threshold of the engine corresponding to the current engine speed and the current ambient pressure value from the set correspondence between engine speed, ambient pressure value and engine average indicated pressure threshold.

[0074] The current engine power parameters include: the current engine speed.

[0075] The operating environment of a vehicle varies depending on the ambient pressure. Vehicles operate at high altitudes with low ambient pressure, while vehicles operate at low altitudes with high ambient pressure.

[0076] Based on this, this application calibrates the engine by changing the engine speed for different environmental pressure values ​​to obtain the engine average indicated pressure threshold under the corresponding operating conditions.

[0077] Among them, the engine average indicated pressure threshold needs to be determined to ensure that the vehicle is not easily disengaged from dynamic VVT when the engine has a large torque demand at high altitudes, so as to ensure the vehicle's power performance in high-altitude environments and to prevent the problem of repeatedly entering and exiting dynamic VVT.

[0078] The correspondence between engine speed, ambient pressure, and engine mean indicated pressure threshold can be found in Table 1.

[0079] Table 1

[0080]

[0081] In Table 1, the horizontal axis x represents engine speed (rpm), the vertical axis y represents ambient pressure (kPa), and the values ​​in Table 1 are the engine average indicated pressure threshold (kPa).

[0082] (2) Determine the target average indicated pressure difference between the current engine speed and the current engine target average indicated pressure from the set correspondence between engine speed, engine target average indicated pressure and average indicated pressure difference.

[0083] The current engine load parameters include: the current engine target mean indicated pressure.

[0084] To balance power and economy, this application engages dynamic VVT when the engine has a high power demand to ensure vehicle power; and disengages dynamic VVT after the engine reaches its power demand to balance vehicle economy.

[0085] When determining the critical value for exiting dynamic VVT, this application considers not only the engine's average indicated pressure threshold at engine speed and different ambient pressure values, but also the difference between the engine's target average indicated pressure (corresponding to the engine's target load) and the engine's actual average indicated pressure (corresponding to the engine's actual load). When this difference is small, it can be determined that the engine's power demand has been met.

[0086] Based on this, this application has calibrated different average indicated pressure difference values ​​for different engine speeds and different engine target average indicated pressures, as detailed in Table 2. The average indicated pressure difference is the pressure difference between the engine target average indicated pressure and the engine actual average indicated pressure. Therefore, after obtaining the current engine speed and the current engine target average indicated pressure, the corresponding target average indicated pressure difference value can be determined by matching it with Table 2.

[0087] Table 2

[0088]

[0089] In Table 2, the horizontal axis x represents engine speed (rpm), and the vertical axis y represents engine target average indicated pressure (kPa). The values ​​in Table 2 are the average indicated pressure difference used when the engine exits dynamic VVT conditions.

[0090] (3) The target average indicated pressure threshold and the difference between the target average indicated pressure are determined as the exit threshold for dynamic VVT.

[0091] In summary, this invention comprehensively considers engine power parameters and the environmental pressure value of the engine operation environment when determining the critical value for exiting dynamic VVT. This ensures that the conditions for exiting dynamic VVT meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid the frequent entry and exit of dynamic VVT when the engine needs a large torque in high-altitude areas. In other words, it can effectively avoid the frequent interruption of power output when the engine has a high power demand, thereby solving the problem of vehicle jerking caused by large fluctuations in vehicle torque.

[0092] In one embodiment, the process of determining the engine average indicated pressure threshold in Table 1 may include:

[0093] (1) Turn off the engine’s dynamic VVT function.

[0094] When calibrating the corresponding engine average indicated pressure threshold under different engine speeds and ambient pressure values, this application requires disabling the engine's dynamic VVT function to avoid affecting the calibration results due to the engine entering and / or exiting dynamic VVT during the calibration process.

[0095] (2) When the vehicle is running on the test road, for each set environmental pressure value, the engine speed is gradually increased from the lower limit of the engine speed according to different torque requirements to obtain the actual average indicated pressure of the engine under different engine target average indicated pressures at the set environmental pressure value, and the actual average indicated pressure of the engine is used as the average indicated pressure test value.

[0096] The test road for the vehicle can be a straight road or an uphill road.

[0097] The average indicated pressure test value is obtained from actual road tests or laboratory tests conducted on vehicles under different set environmental pressure values ​​and different engine speeds.

[0098] For each set environmental pressure value, for example, an environmental pressure value of 55 kPa, the engine speed is started from the lower limit of the engine speed, for example, the lower limit of the engine speed is 800 rpm, and accelerated according to different torque requirements (for example, 40%, 50%, 60%, 70%, 80%, 100% of the maximum torque) to obtain the value that the actual average indicated pressure of the engine can reach under different target average indicated pressures at the set environmental pressure value. This application uses the value that the actual average indicated pressure of the engine can reach as the average indicated pressure test value.

[0099] (3) Based on the average indicated pressure test value and the set pressure error range, determine the engine average indicated pressure threshold.

[0100] The average indicated pressure test value obtained in this application is a calibration value under ideal operating conditions. In order to improve the accuracy of the calibration value, it is necessary to use a set pressure error range to correct the average indicated pressure test value obtained in the calibration, so as to obtain an engine average indicated pressure threshold that is more in line with the actual operating conditions, so as to ensure the accuracy of the final determined exit condition of dynamic VVT, and effectively avoid the situation of frequent engine entry and exit of dynamic VVT while taking into account both power and economy.

[0101] In one embodiment, the process of determining the engine average indicated pressure threshold based on the average indicated pressure test value and the set pressure error range may specifically include:

[0102] (1) Determine whether the set environmental pressure value is less than the environmental pressure boundary value.

[0103] The environmental pressure threshold is used to distinguish between high-altitude and low-altitude environments. The specific value is determined according to actual needs. For example, the environmental pressure threshold is 80 kPa.

[0104] In practical applications, when vehicles operate in high-altitude environments, after the engine exits dynamic VVT (Variable Valve Timing) according to the traditional exit conditions, the engine's charging efficiency is low due to the vehicle's operating conditions. This necessitates boosting to reach the target average indicated pressure, causing the actual average indicated pressure of the engine after exiting dynamic VVT to quickly fall below the target average indicated pressure. This causes the engine to meet the conditions for re-entering dynamic VVT again, resulting in frequent shifts in dynamic VVT. However, this frequent shifting typically does not occur when vehicles operate in low-altitude environments. Therefore, this application sets different set pressure error ranges for different ambient pressure values.

[0105] (2) If the set environmental pressure value is less than the environmental pressure threshold value, it is determined that the vehicle is operating in the high-altitude environment.

[0106] It is understandable that the environmental pressure value of a vehicle is usually lower in a high-altitude environment. Therefore, this application can determine that the vehicle is operating in a high-altitude environment when the set environmental pressure value is less than the environmental pressure threshold value.

[0107] (3) The difference between the average indicated pressure test value and the first pressure error amplitude is determined as the engine average indicated pressure threshold.

[0108] The set pressure error range includes: the first pressure error range.

[0109] The engine average indicated pressure threshold determined in this application should not be set too low, so as to avoid the inability to disengage dynamic VVT when the engine target average indicated pressure is low, thereby causing economic losses.

[0110] The value of the first pressure error range depends on the actual needs and can be taken within the range of [50 kPa, 100 kPa].

[0111] It should be noted that the engine average indicated pressure threshold in Table 1 is set smaller in high-altitude environments (low ambient pressure values) compared to low-altitude environments. This ensures that when the engine has a large torque demand, if the engine enters dynamic VVT under the conditions, it is not easy to exit dynamic VVT. In other words, the target average indicated pressure of the engine in high-altitude environments is not easy to reach the set engine average indicated pressure threshold, and therefore it is not easy to meet the conditions for exiting dynamic VVT. This ensures the engine's power performance in high-altitude environments and prevents the problem of repeatedly entering and exiting dynamic VVT.

[0112] The engine mean indicated pressure threshold in Table 1 is set to a larger value in low-altitude environments (high ambient pressure values) than in high-altitude environments. This can prevent the dynamic VVT from disengaging normally in low-altitude environments (i.e., plain environments) to ensure fuel economy.

[0113] Therefore, in one embodiment, the process of determining the engine average indicated pressure threshold based on the average indicated pressure test value and the set pressure error range may specifically include:

[0114] (1) If the set environmental pressure value is not less than the environmental pressure threshold value, it is determined that the vehicle is operating in the low-altitude environment;

[0115] It is understandable that the environmental pressure value of a vehicle is usually higher in a low-altitude environment. Therefore, when this application determines that the set environmental pressure value is not less than the environmental pressure threshold value, it can be determined that the vehicle is operating in a low-altitude environment.

[0116] (2) The sum of the average indicated pressure test value and the second pressure error amplitude is determined as the engine average indicated pressure threshold;

[0117] The set pressure error range includes the second pressure error range.

[0118] When a vehicle operates in a low-altitude environment, the engine typically does not frequently engage and disengage dynamic VVT. To balance vehicle power and fuel economy, when operating at low altitudes, dynamic VVT should only be engaged when the vehicle has a power demand (e.g., the engine needs high torque), and disengaged from dynamic VVT and returned to normal VVT once the engine's power demand is met.

[0119] Based on this, this application appropriately increases the average indicated pressure test value, that is, the sum of the average indicated pressure test value and the second pressure error amplitude is used as the engine average indicated pressure threshold in Table 1.

[0120] The value of the second pressure error range is determined according to actual needs and can be taken within the range of [100 kPa, 200 kPa].

[0121] In one embodiment, the process of determining the average indicated pressure difference in Table 2 may include:

[0122] (1) When the vehicle is running on the test road, for each set engine target average indicated pressure, the engine speed is gradually accelerated from the lower limit of the engine speed according to different torque requirements.

[0123] For each set engine target average indicated pressure, such as 300 kPa, start the engine speed from the lower limit of engine speed, such as 800 rpm, and gradually accelerate according to different torque requirements (such as 40%, 50%, 60%, 70%, 80%, 100% of the maximum torque).

[0124] (2) Under each set engine target average indicated pressure and each engine speed, determine the average indicated pressure difference corresponding to the torque difference between the actual engine torque and the engine target torque being less than the difference threshold.

[0125] At each set engine target average indicated pressure and each engine speed, when the torque difference between the actual engine torque and the engine target torque is less than the difference threshold (i.e., when the actual engine torque is close to the engine target torque), the difference between the engine target average indicated pressure and the engine actual average indicated pressure is taken as the average indicated pressure difference under that operating condition.

[0126] The difference threshold is used to characterize the degree of closeness between the actual engine torque and the target engine torque. When the torque difference between the actual engine torque and the target engine torque is less than the difference threshold, it can be determined that the actual engine torque is close to the target engine torque.

[0127] In one embodiment, step S103 may specifically include:

[0128] When the difference between the current engine target average indicated pressure and the current engine actual average indicated pressure is less than the target average indicated pressure difference, and the current engine target average indicated pressure is less than the engine target average indicated pressure threshold, the current engine load parameter is determined to meet the exit dynamic VVT critical value.

[0129] Control the engine to disengage from the dynamic VVT;

[0130] The current engine load parameters include: the current engine target average indicated pressure and the current engine actual average indicated pressure;

[0131] The threshold values ​​for exiting dynamic VVT include: the target average indicated pressure difference obtained from Table 2, and the engine target average indicated pressure threshold obtained from Table 1.

[0132] The engine control method in this application specifically includes the following:

[0133] (1) This application obtains the current engine load parameters (including the current engine target average indicated pressure and the current engine actual average indicated pressure), the current engine power parameters (including the current engine speed) and the current environmental pressure value of the vehicle when the engine enters dynamic VVT.

[0134] (2) Determine the corresponding engine target average indicated pressure threshold from Table 1 based on the current engine speed and current ambient pressure value.

[0135] (3) Based on the current engine speed and the current engine target average indicated pressure, determine the corresponding target average indicated pressure difference from Table 2.

[0136] (4) Calculate the difference between the current engine target average indicated pressure and the current engine actual average indicated pressure. When the difference is less than the target average indicated pressure difference and the current engine target average indicated pressure is less than the engine target average indicated pressure threshold, determine that the current engine load parameters meet the exit dynamic VVT critical value. At this time, control the engine to exit dynamic VVT.

[0137] In summary, this application comprehensively considers engine power parameters and the environmental pressure value of the engine operation environment when determining the conditions for exiting dynamic VVT. This ensures that the conditions for exiting dynamic VVT meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid the frequent entry and exit of dynamic VVT when the engine needs a large torque in high-altitude areas. In other words, it can effectively avoid the frequent interruption of power output when the engine has a high power demand, thereby solving the problem of vehicle jerking caused by large fluctuations in vehicle torque.

[0138] It should be noted that in practical applications, the selection of dynamic VVT parameters can be determined on an engine test bench based on measured fuel consumption rate, charging efficiency, knock performance, and other factors, according to the engine's power and economy requirements.

[0139] In one embodiment, this application also discloses the process of an engine entering dynamic VVT, specifically including:

[0140] (1) Obtain the current operating condition information of the engine.

[0141] The current operating condition information includes: engine target average indicated pressure, engine actual average indicated pressure, throttle pedal opening, target air-fuel ratio, and engine speed.

[0142] (2) When the current operating condition information meets the conditions for entering dynamic VVT, control the engine to enter the dynamic VVT.

[0143] Specifically, the conditions for an engine to enter dynamic VVT can be as follows:

[0144] Engine target average indicated pressure - engine actual average indicated pressure > a;

[0145] Accelerator pedal opening is greater than 0%;

[0146] Target air-fuel mixture > b;

[0147] Engine speed < c.

[0148] In practical applications, the values ​​of a, b, and c can be determined according to the actual situation. For example, the range of a is [100 kPa, 300 kPa], the value of b can be 12, and the value of c can be 6000 rpm.

[0149] It should be noted that the conditions for an engine to enter dynamic VVT include:

[0150] Engine target average indicated pressure - engine actual average indicated pressure > a;

[0151] The conditions for the engine to deactivate dynamic VVT include:

[0152] Engine target average indicated pressure - engine actual average indicated pressure < d, where d is determined from Table 2;

[0153] To avoid frequent shifts in dynamic VVT when the vehicle is operating at high altitudes, the value of d is less than the value of a under the same engine speed and target average indicated pressure.

[0154] When calibrating the d-value, the d-value is: the average indicated pressure difference when the torque difference between the actual engine torque and the engine target torque is less than the difference threshold (i.e., when the actual engine torque is close to the engine target torque) at each set engine target average indicated pressure and each engine speed.

[0155] When calibrating the a-value, the a-value is the average indicated pressure difference when the torque difference between the actual engine torque and the engine target torque is greater than the target difference threshold at each set engine target average indicated pressure and each engine speed (i.e., when the difference between the actual engine torque and the engine target torque is large).

[0156] This application avoids frequent shifts in and out of dynamic VVT by setting a sufficient difference between the value 'a' when the engine enters dynamic VVT and the value 'd' when the engine exits dynamic VVT.

[0157] The possible values ​​for 'a' are shown in Table 3.

[0158] Table 3

[0159]

[0160] The horizontal axis of Table 3 represents engine speed (rpm), and the vertical axis represents the engine target mean indicated pressure (kPa). The values ​​in Table 3 are the mean indicated pressure difference used when the engine enters dynamic VVT conditions.

[0161] Corresponding to the above method embodiments, the present invention also discloses an engine control device.

[0162] See Figure 2 The present invention discloses a schematic diagram of an engine control device, which is applied to an engine controller and may include:

[0163] The acquisition unit 201 is used to acquire the current engine load parameters, the current engine power parameters, and the current environmental pressure value of the vehicle when the engine enters dynamic VVT.

[0164] Preferably, the engine in this application can be a Miller cycle engine.

[0165] The actual average indicated pressure of the engine refers to the actual average indicated pressure obtained during the actual operation of the engine.

[0166] Engine target mean indicated pressure refers to the engine's expected mean indicated pressure.

[0167] In practical applications, the process of determining the target mean indicated pressure of an engine may include:

[0168] (1) When it is a hybrid vehicle, the target average indicated pressure of the engine is obtained based on the engine's required torque.

[0169] The specific process of obtaining the target average indicated pressure of the engine based on the engine's required torque can be found in existing solutions and will not be repeated here.

[0170] (2) When it is a fuel vehicle, first determine the corresponding engine torque demand based on the accelerator pedal opening, and then obtain the engine target average indicated pressure based on the engine torque demand.

[0171] The current engine power parameters in this application include, but are not limited to, engine speed.

[0172] In this application, when the engine enters dynamic VVT due to power demand, the engine controller will acquire the engine load parameters, engine power parameters, and environmental pressure values ​​at various times in real time.

[0173] In practical applications, the current ambient pressure value at which the engine is operating can be used to determine whether the environment is at high or low altitude.

[0174] The critical value determination unit 202 is used to determine the critical value for exiting dynamic VVT that meets the current engine operating conditions based on the current engine power parameters and the current environmental pressure value.

[0175] This application determines the critical value for exiting dynamic VVT based on real-time engine power parameters and the ambient pressure value under which the engine operates. That is, the critical value for exiting dynamic VVT differs for different engine power parameters and ambient pressure values ​​in this application.

[0176] The exit control unit 203 is used to control the engine to exit the dynamic VVT when the current engine load parameters and the exit dynamic VVT threshold value meet the exit dynamic VVT conditions.

[0177] It should be noted that the threshold for exiting dynamic VVT includes multiple thresholds, and the thresholds vary depending on the engine load parameters.

[0178] In summary, this application discloses an engine control device that, when the engine enters dynamic VVT, acquires the current engine load parameters, current engine power parameters, and the current ambient pressure value where the engine is operating. Based on the current engine power parameters and the current ambient pressure value, it determines the threshold value for exiting dynamic VVT that meets the current engine operating conditions. When the current engine load parameters and the threshold value for exiting dynamic VVT meet the exit conditions, the device controls the engine to exit dynamic VVT. This application comprehensively considers the engine power parameters and the ambient pressure value where the engine is operating when determining the exit conditions, thus ensuring that the exit conditions meet the engine's operating environment and power requirements. Therefore, after the engine enters dynamic VVT, it can effectively avoid frequent entry and exit of dynamic VVT when the engine requires high torque in high-altitude areas, effectively preventing frequent interruptions in engine power output during periods of high power demand. This solves the problem of vehicle jerking caused by large fluctuations in vehicle torque.

[0179] In one embodiment, the critical value determination unit 202 can be specifically used for:

[0180] The pressure threshold determination subunit is used to determine the target average indicated pressure threshold of the engine corresponding to the current engine speed and the current ambient pressure value from the set correspondence between engine speed, ambient pressure value and engine average indicated pressure threshold, wherein the current engine power parameter includes: the current engine speed;

[0181] The pressure difference determination subunit is used to determine the target average indicated pressure difference corresponding to the current engine speed and the current engine target average indicated pressure from the set correspondence between engine speed, engine target average indicated pressure and average indicated pressure difference, wherein the current engine load parameter includes: the current engine target average indicated pressure;

[0182] The critical value determination subunit is used to determine the target average indicated pressure threshold and the difference between the target average indicated pressure as the critical value for exiting dynamic VVT.

[0183] In one embodiment, the pressure threshold determination subunit can specifically be used for:

[0184] Turn off the engine's dynamic VVT function;

[0185] When the vehicle is running on the test road, for each set environmental pressure value, the engine speed is gradually increased from the lower limit of the engine speed according to different torque requirements to obtain the actual average indicated pressure of the engine under different engine target average indicated pressures at the set environmental pressure value, and the actual average indicated pressure of the engine is used as the average indicated pressure test value.

[0186] The engine average indicated pressure threshold is determined based on the average indicated pressure test value and the set pressure error range.

[0187] In one embodiment, the pressure threshold determination subunit can also be used for:

[0188] Determine whether the set environmental pressure value is less than the environmental pressure threshold value, wherein the environmental pressure threshold value is used to divide high-altitude environment and low-altitude environment;

[0189] If the set environmental pressure value is less than the environmental pressure threshold value, it is determined that the vehicle is operating in the high-altitude environment.

[0190] The difference between the average indicated pressure test value and the first pressure error amplitude is determined as the engine average indicated pressure threshold.

[0191] The set pressure error range includes: the first pressure error range.

[0192] In one embodiment, the pressure threshold determination subunit can also be used for:

[0193] If the set environmental pressure value is not less than the environmental pressure threshold value, it is determined that the vehicle is operating in the low-altitude environment.

[0194] The sum of the average indicated pressure test value and the second pressure error amplitude is determined as the engine average indicated pressure threshold.

[0195] The set pressure error range includes the second pressure error range.

[0196] In one embodiment, the pressure difference determination subunit can be specifically used for:

[0197] With the vehicle running on the test road, for each set engine target average indicated pressure, the engine speed is gradually accelerated from the lower limit of the engine speed according to different torque requirements.

[0198] For each set engine target average indicated pressure and each engine speed, the average indicated pressure difference is determined when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold.

[0199] In one embodiment, the exit control unit 203 can be specifically used for:

[0200] When the difference between the current engine target average indicated pressure and the current engine actual average indicated pressure is less than the target average indicated pressure difference, and the current engine target average indicated pressure is less than the engine target average indicated pressure threshold, the current engine load parameter is determined to meet the exit dynamic VVT critical value.

[0201] Control the engine to disengage from the dynamic VVT;

[0202] The current engine load parameters include: the current engine target average indicated pressure and the current engine actual average indicated pressure;

[0203] The threshold for exiting dynamic VVT includes: the target average indicated pressure difference and the engine target average indicated pressure threshold.

[0204] In one embodiment, engine control may further include:

[0205] Dynamic VVT entry unit, used for:

[0206] Obtain the current operating condition information of the engine;

[0207] If the current operating condition information meets the conditions for entering dynamic VVT, control the engine to enter dynamic VVT;

[0208] The current operating condition information includes: engine target average indicated pressure, engine actual average indicated pressure, throttle pedal opening, target air-fuel ratio, and engine speed.

[0209] It should be noted that for the specific working principles of each component in the device embodiment, please refer to the corresponding section of the method embodiment, which will not be repeated here.

[0210] Corresponding to the above embodiments, see [link to relevant documentation]. Figure 3 The present invention discloses a schematic diagram of the structure of an engine controller in a vehicle. The engine controller may include: a processor 1 and a memory 2.

[0211] The processor 1 and memory 2 communicate with each other via communication bus 3.

[0212] Processor 1, for executing at least one instruction;

[0213] Memory 2 is used to store at least one instruction;

[0214] Processor 1 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0215] Memory 2 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0216] The processor executes at least one instruction to implement the steps shown in the embodiment of the engine control method.

[0217] Corresponding to the above embodiments, the present invention also discloses a computer storage medium that stores at least one instruction, which, when executed by a processor, implements the steps shown in the embodiments of the engine control method.

[0218] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0219] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0220] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine control method, characterized in that, include: When the engine enters dynamic VVT, acquire the current engine load parameters, current engine power parameters, and the current environmental pressure value of the vehicle. Based on the current engine power parameters and the current ambient pressure value, determine the critical value for exiting dynamic VVT that meets the current engine operating conditions; If the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions, control the engine to exit the dynamic VVT. The step of determining the critical value for exiting dynamic VVT based on the current engine power parameters and the current ambient pressure value includes: From the established correspondence between engine speed, ambient pressure value, and engine average indicated pressure threshold, determine the engine target average indicated pressure threshold corresponding to the current engine speed and the current ambient pressure value, wherein the current engine power parameters include: the current engine speed; From the established correspondence between engine speed, engine target average indicated pressure, and average indicated pressure difference, the target average indicated pressure difference corresponding to the current engine speed and the current engine target average indicated pressure is determined, wherein the current engine load parameter includes: the current engine target average indicated pressure; The target average indicated pressure threshold and the difference between the target average indicated pressure are determined as the exit threshold for dynamic VVT.

2. The engine control method according to claim 1, characterized in that, The process for determining the engine's average indicated pressure threshold includes: Turn off the engine's dynamic VVT function; When the vehicle is running on the test road, for each set environmental pressure value, the engine speed is gradually increased from the lower limit of the engine speed according to different torque requirements to obtain the actual average indicated pressure of the engine under different engine target average indicated pressures at the set environmental pressure value, and the actual average indicated pressure of the engine is used as the average indicated pressure test value. The engine average indicated pressure threshold is determined based on the average indicated pressure test value and the set pressure error range.

3. The engine control method according to claim 2, characterized in that, Determining the engine average indicated pressure threshold based on the average indicated pressure test value and the set pressure error range includes: Determine whether the set environmental pressure value is less than the environmental pressure threshold value, wherein the environmental pressure threshold value is used to divide high-altitude environment and low-altitude environment; If the set environmental pressure value is less than the environmental pressure threshold value, it is determined that the vehicle is operating in the high-altitude environment. The difference between the average indicated pressure test value and the first pressure error amplitude is determined as the engine average indicated pressure threshold. The set pressure error range includes: the first pressure error range.

4. The engine control method according to claim 3, characterized in that, Also includes: If the set environmental pressure value is not less than the environmental pressure threshold value, it is determined that the vehicle is operating in the low-altitude environment. The sum of the average indicated pressure test value and the second pressure error amplitude is determined as the engine average indicated pressure threshold. The set pressure error range includes the second pressure error range.

5. The engine control method according to claim 1, characterized in that, The process for determining the average indicated pressure difference includes: With the vehicle running on the test road, for each set engine target average indicated pressure, the engine speed is gradually accelerated from the lower limit of the engine speed according to different torque requirements. For each set engine target average indicated pressure and each engine speed, the average indicated pressure difference is determined when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold.

6. The engine control method according to any one of claims 1 to 5, characterized in that, The step of controlling the engine to exit the dynamic VVT when the current engine load parameters and the exit dynamic VVT threshold meet the exit dynamic VVT conditions includes: When the difference between the current engine target average indicated pressure and the current engine actual average indicated pressure is less than the target average indicated pressure difference, and the current engine target average indicated pressure is less than the engine target average indicated pressure threshold, the current engine load parameter is determined to meet the exit dynamic VVT critical value. Control the engine to disengage from the dynamic VVT; The current engine load parameters include: the current engine target average indicated pressure and the current engine actual average indicated pressure; The threshold for exiting dynamic VVT includes: the target average indicated pressure difference and the engine target average indicated pressure threshold.

7. The engine control method according to claim 1, characterized in that, The process by which the engine enters the dynamic VVT includes: Obtain the current operating condition information of the engine; If the current operating condition information meets the conditions for entering dynamic VVT, control the engine to enter dynamic VVT; The current operating condition information includes: engine target average indicated pressure, engine actual average indicated pressure, throttle pedal opening, target air-fuel ratio, and engine speed.

8. An engine control device, characterized in that, include: The acquisition unit is used to acquire the current engine load parameters, current engine power parameters, and the current environmental pressure value of the vehicle when the engine enters dynamic VVT. The critical value determination unit is used to determine the critical value for exiting dynamic VVT that meets the current engine operating conditions based on the current engine power parameters and the current ambient pressure value. The exit control unit is used to control the engine to exit the dynamic VVT when the current engine load parameters and the exit dynamic VVT threshold value meet the exit dynamic VVT conditions; The critical value determination unit includes: The pressure threshold determination subunit is used to determine the target average indicated pressure threshold of the engine corresponding to the current engine speed and the current ambient pressure value from the set correspondence between engine speed, ambient pressure value and engine average indicated pressure threshold, wherein the current engine power parameter includes: the current engine speed; The pressure difference determination subunit is used to determine the target average indicated pressure difference corresponding to the current engine speed and the current engine target average indicated pressure from the set correspondence between engine speed, engine target average indicated pressure and average indicated pressure difference, wherein the current engine load parameter includes: the current engine target average indicated pressure; The critical value determination subunit is used to determine the target average indicated pressure threshold and the difference between the target average indicated pressure as the critical value for exiting dynamic VVT.

9. A vehicle, comprising an engine controller, characterized in that, The engine controller includes a memory and a processor; The memory is used to store at least one instruction; The processor is used to execute the at least one instruction to implement the engine control method as described in any one of claims 1 to 7.

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