Engine control method and related device

Abstract

The invention discloses an engine control method and a related device, and the method comprises the steps: obtaining a current engine load parameter, a current engine power parameter and a current environment pressure value of the operation of an engine under the condition that the engine enters a dynamic VVT (Variable Valve Timing), and obtaining a control parameter of the engine based on the current engine power parameter and the current environment pressure value; and determining a quit dynamic VVT critical value meeting the current engine working condition, and controlling the engine to quit the dynamic VVT under the condition that the current engine load parameter and the quit dynamic VVT critical value meet the quit dynamic VVT condition. According to the method, when the dynamic VVT condition is determined to exit, the engine power parameters and the pressure value of the environment where the engine runs are comprehensively considered, so that it can be guaranteed that the dynamic VVT condition is exited to meet the running environment and power requirements of the engine, and the dynamic VVT condition can be exited under the condition that the required torque of the engine in a high-altitude area is large. And the condition that the engine frequently advances and retreats into the dynamic VVT is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of engine control, and more particularly to an engine control method and related devices. Background Art

[0002] The engine's dynamic VVT (Variable Valve Timing) is a technology that has been gradually applied to vehicles in recent years. When the engine needs power, the dynamic VVT is activated to meet the power demand. In order to balance the engine's power and economy, the dynamic VVT is currently only used when the engine has power requirements (for example, the engine needs high torque). When the engine's power requirements are met, the dynamic VVT is exited and returned to normal VVT.

[0003] When the vehicle is traveling at high altitude and the engine enters Dynamic VVT, the engine will exit Dynamic VVT when the Dynamic VVT exit conditions are met. Due to the vehicle's operating conditions, the engine's charging efficiency will be low and pressure needs to be increased to reach the target average indicated pressure. At this time, the engine's actual average indicated pressure after exiting Dynamic VVT quickly falls below the target average indicated pressure, causing the engine to meet the conditions for entering Dynamic VVT again and enter Dynamic VVT again. This cycle repeats itself, causing the engine to frequently enter and exit Dynamic VVT, resulting in large fluctuations in vehicle torque and vehicle jerking. Summary of the invention

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

[0005] An engine control method, comprising:

[0006] When the engine enters dynamic VVT, the current engine load parameter, the current engine power parameter and the current environmental pressure value under which the vehicle is running are obtained;

[0007] Determining a critical value for exiting dynamic VVT that satisfies a current engine operating condition based on the current engine power parameter and the current ambient pressure value;

[0008] When the current engine load parameter and the dynamic VVT exit threshold value satisfy a dynamic VVT exit condition, the engine is controlled to exit the dynamic VVT.

[0009] Optionally, the determining, based on the current engine power parameter and the current ambient pressure value, a critical value for exiting the dynamic VVT that satisfies the current engine operating condition includes:

[0010] Determining the target engine mean indicated pressure threshold corresponding to the current engine speed and the current ambient pressure value from the set corresponding relationship between the engine speed, the ambient pressure value and the engine mean indicated pressure threshold, wherein the current engine power parameter includes: the current engine speed;

[0011] Determining the target mean indicated pressure difference corresponding to the current engine speed and the current engine target mean indicated pressure from the set corresponding relationship between the engine speed, the engine target mean indicated pressure and the mean indicated pressure difference, wherein the current engine load parameter includes: the current engine target mean indicated pressure;

[0012] The engine target indicated mean pressure threshold and the target indicated mean pressure difference are determined as the dynamic VVT exit critical value.

[0013] Optionally, the process of determining the engine indicated mean pressure threshold comprises:

[0014] Turning off the dynamic VVT function of the engine;

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

[0016] The engine mean indicated pressure threshold is determined based on the mean indicated pressure test value and a set pressure error margin.

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

[0018] Determining whether the set environmental pressure value is less than an environmental pressure dividing value, wherein the environmental pressure dividing value is used to divide a high altitude environment and a low altitude environment;

[0019] If the set environmental pressure value is less than the environmental pressure threshold value, determining that the vehicle is operating in the high altitude environment;

[0020] Determine the difference between the average indicated pressure test value and the first pressure error amplitude as the engine average indicated pressure threshold;

[0021] Wherein, 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, determining that the vehicle is operating in the low altitude environment;

[0024] Determine the sum of the mean indicated pressure test value and the second pressure error amplitude as the engine mean indicated pressure threshold;

[0025] Wherein, the set pressure error range includes: the second pressure error range.

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

[0027] When the vehicle is running on the test road, for each set engine target indicated mean pressure, the engine speed is gradually accelerated from the engine speed lower limit value according to different torque requirements;

[0028] Under each of the set engine target indicated mean pressure and each of the engine speeds, the mean indicated pressure difference corresponding to when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold is determined.

[0029] Optionally, when the current engine load parameter and the critical value for exiting dynamic VVT satisfy a condition for exiting dynamic VVT, controlling the engine to exit the dynamic VVT comprises:

[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, determining that the current engine load parameter satisfies the dynamic VVT exit critical value;

[0031] Controlling the engine to exit the dynamic VVT;

[0032] Wherein, the current engine load parameter includes: the current engine target mean indicated pressure and the current engine actual mean indicated pressure;

[0033] The dynamic VVT exit critical value includes: the target indicated mean pressure difference value and the engine target indicated mean pressure threshold value.

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

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

[0036] When the current operating condition information satisfies a condition for entering dynamic VVT, controlling the engine to enter the dynamic VVT;

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

[0038] An engine control device, comprising:

[0039] An acquisition unit, used for acquiring a current engine load parameter, a current engine power parameter, and a current environmental pressure value in which the vehicle is running when the engine enters dynamic VVT;

[0040] a critical value determination unit, configured to determine a critical value for exiting dynamic VVT that satisfies a current engine operating condition based on the current engine power parameter and the current ambient pressure value;

[0041] An exit control unit is used to control the engine to exit the dynamic VVT when the current engine load parameter and the dynamic VVT exit critical value meet the dynamic VVT exit condition.

[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] It can be seen from the above technical solutions that the present invention discloses an engine control method and related devices. When the engine enters dynamic VVT, the current engine load parameter, the current engine power parameter and the current environmental pressure value in which the engine is running are obtained. Based on the current engine power parameter and the current environmental pressure value, the critical value for exiting dynamic VVT that satisfies the current engine working condition is determined. When the current engine load parameter and the critical value for exiting dynamic VVT meet the conditions for exiting dynamic VVT, the engine is controlled to exit dynamic VVT. When determining the conditions for exiting dynamic VVT, the present application comprehensively considers the engine power parameter and the environmental pressure value in which the engine is running, so as to ensure that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT in high-altitude areas when the engine torque demand is large, that is, effectively avoid the situation where the output power is frequently interrupted when the engine has high power demand, thereby solving the problem of vehicle jerking caused by large-scale fluctuations in vehicle torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without paying creative work.

[0047] Figure 1 A flow chart of an engine control method disclosed in an embodiment of the present invention;

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

[0049] Figure 3 The present invention is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The embodiment of the present invention discloses an engine control method and related devices. When the engine enters dynamic VVT, the current engine load parameter, the current engine power parameter and the current environmental pressure value in which the engine is running are obtained. Based on the current engine power parameter and the current environmental pressure value, the critical value for exiting dynamic VVT that satisfies the current engine working condition is determined. When the current engine load parameter and the critical value for exiting dynamic VVT meet the conditions for exiting dynamic VVT, the engine is controlled to exit dynamic VVT. When determining the conditions for exiting dynamic VVT, the present application comprehensively considers the engine power parameter and the environmental pressure value in which the engine is running, so as to ensure that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT in high-altitude areas when the engine torque demand is large, that is, it effectively avoids the situation where the output power is frequently interrupted when the engine has high power demand, thereby solving the problem of vehicle jerking caused by large-scale fluctuations in vehicle torque.

[0052] See also Figure 1 , a flow chart of an engine control method disclosed in an embodiment of the present invention, the method is applied to an engine controller, and the control method may include:

[0053] Step S101: When the engine enters dynamic VVT, obtain the current engine load parameter, the current engine power parameter and the current environmental pressure value under which the vehicle is running.

[0054] Preferably, the engine in the present application may be a Miller cycle engine.

[0055] Dynamic VVT (Variable Valve Timing) is an important innovation in modern engine technology. It optimizes engine performance by intelligently controlling the phase of the engine cam so that the opening and closing time of the valve can be dynamically adjusted as the engine speed changes.

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

[0057] Mean Indicated Pressure (MIP) is the indicated work done by the engine per cylinder working volume in one cycle, and is an important indicator for measuring the actual cycle power performance of the engine. Mean Indicated Pressure is not a real force, but a ratio of work to volume. It reflects the utilization rate of the engine cylinder working volume, that is, the ratio of the average work done by the working fluid in the cylinder on the piston to the cylinder working volume. The higher the mean indicated pressure, the better the engine's working cycle is and the higher the utilization 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] The target engine indicated mean pressure refers to the desired indicated mean pressure of the engine.

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

[0061] (1) For hybrid vehicles, the target indicated mean pressure of the engine is obtained based on the engine demand torque.

[0062] Among them, the specific process of obtaining the target average indicated pressure of the engine according to the engine demand torque can be referred to the existing scheme, which will not be repeated here.

[0063] (2) For fuel vehicles, the corresponding engine demand torque is first determined based on the accelerator pedal opening, and then the engine target average indicated pressure is obtained based on the engine demand torque.

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

[0065] In this application, when the engine has a power demand and enters dynamic VVT, the engine controller will obtain the engine load parameters, engine power parameters and the environmental pressure value of the engine operation at each moment in real time.

[0066] In practical applications, it can be determined whether the environment in which the engine is located is a high-altitude environment or a low-altitude environment according to the current environmental pressure value in which the engine is running.

[0067] Step S102: Determine a critical value for exiting dynamic VVT that satisfies the current engine operating condition based on the current engine power parameter and the current ambient pressure value.

[0068] This application determines the critical value of exiting dynamic VVT that satisfies the corresponding engine operating condition based on the real-time engine power parameters and the environmental pressure value in which the engine is running. That is, under different engine power parameters and environmental pressure values ​​in this application, the corresponding critical value of exiting dynamic VVT is different.

[0069] Step S103: When the current engine load parameter and the critical value for exiting dynamic VVT satisfy a condition for exiting dynamic VVT, control the engine to exit the dynamic VVT.

[0070] It should be noted that the critical value for exiting dynamic VVT includes multiple critical values, and different engine load parameters correspond to different critical values.

[0071] In summary, the present application discloses an engine control method, in the case where the engine enters dynamic VVT, the current engine load parameter, the current engine power parameter and the current environmental pressure value in which the engine is running are obtained, based on the current engine power parameter and the current environmental pressure value, the critical value for exiting dynamic VVT that satisfies the current engine working condition is determined, and in the case where the current engine load parameter and the critical value for exiting dynamic VVT meet the conditions for exiting dynamic VVT, the engine is controlled to exit dynamic VVT. When determining the conditions for exiting dynamic VVT, the present application comprehensively considers the engine power parameters and the environmental pressure value in which the engine is running, so as to ensure that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT in high altitude areas when the engine torque demand is large, that is, it effectively avoids the situation where the output power is frequently interrupted when the engine has high power demand, thereby solving the problem of vehicle jerking caused by large-scale fluctuations in vehicle torque.

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

[0073] (1) Determining an engine target mean indicated pressure threshold corresponding to a current engine speed and the current ambient pressure value from a correspondence relationship among a set engine speed, an ambient pressure value, and an engine mean indicated pressure threshold value.

[0074] Among them, the current engine power parameters include: current engine speed.

[0075] Generally, the operating environment of a vehicle will be different depending on the environmental pressure value of the vehicle. When a vehicle is operating in a high-altitude environment, the corresponding environmental pressure value of the vehicle is low; conversely, when a vehicle is operating in a low-altitude environment, the corresponding environmental pressure value of the vehicle is high.

[0076] Based on this, the present application performs calibration for different ambient pressure values ​​by changing the engine speed to obtain the engine average indicated pressure threshold under the corresponding working conditions.

[0077] Among them, when determining the engine mean indicated pressure threshold, it is necessary to ensure that the vehicle is not easy to exit dynamic VVT when it is at high altitude and the engine has a large torque demand, so as to ensure the vehicle's power in high-altitude environment and avoid the problem of repeatedly entering and exiting dynamic VVT.

[0078] The corresponding relationship between the engine speed, the ambient pressure value and the engine average indicated pressure threshold value can be seen in Table 1.

[0079] Table 1

[0080]

[0081] The horizontal coordinate x in Table 1 is: engine speed (rpm), the vertical coordinate y is: ambient pressure value (kPa), and the value in Table 1 is the engine average indicated pressure threshold (kPa).

[0082] (2) Determining a target mean indicated pressure difference corresponding to the current engine speed and the current engine target mean indicated pressure from a correspondence relationship among the set engine speed, the engine target mean indicated pressure, and the mean indicated pressure difference.

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

[0084] In order to take into account both power and economy, the present application enters dynamic VVT when the engine has a greater power demand to ensure vehicle power; and exits dynamic VVT after the engine reaches the power demand to take into account vehicle economy.

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

[0086] Based on this, the present application calibrates different mean indicated pressure differences for different engine speeds and different engine target mean indicated pressures, as shown in Table 2. The mean indicated pressure difference is the pressure difference between the engine target mean indicated pressure and the engine actual mean indicated pressure. Therefore, after obtaining the current engine speed and the current engine target mean indicated pressure, the corresponding target mean indicated pressure difference can be determined by matching with Table 2.

[0087] Table 2

[0088]

[0089] Among them, the horizontal axis x in Table 2 is the engine speed (rpm), the vertical axis y is: the engine target average indicated pressure (kPa), and the values ​​in Table 2 are the average indicated pressure difference used in the engine exit dynamic VVT conditions.

[0090] (3) Determining the engine target indicated mean pressure threshold and the target indicated mean pressure difference as the dynamic VVT exit critical value.

[0091] In summary, the present invention comprehensively considers the engine power parameters and the environmental pressure values ​​in which the engine is running when determining the critical value for exiting dynamic VVT, thereby ensuring that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT when the engine torque demand is large in high altitude areas, that is, it effectively avoids the situation where the output power is frequently interrupted when the engine has 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 indicated mean 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 different ambient pressure values, the present application needs to turn off the engine's dynamic VVT function to avoid the calibration result being affected by the engine entering dynamic VVT and / or exiting dynamic VVT during the calibration process.

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

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

[0097] The average indicated pressure test value is obtained by actual road testing of the vehicle at different set ambient pressure values ​​and different engine speeds or by testing in the laboratory.

[0098] For each set ambient pressure value operating condition, for example, the ambient pressure value is 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 of the actual average indicated pressure of the engine that can be reached at different engine target average indicated pressures under the set ambient 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) Determining the engine average indicated pressure threshold value based on the average indicated pressure test value and the set pressure error margin.

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

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

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

[0103] The environmental pressure dividing value is used to divide the high-altitude environment and the low-altitude environment, and the specific value is determined according to actual needs. For example, the environmental pressure dividing value is 80 kPa.

[0104] In actual applications, when a vehicle is usually running in a high-altitude environment, after the engine meets the traditional dynamic VVT exit conditions and exits the dynamic VVT, the vehicle's operating conditions will cause the engine's charging efficiency to be low, and supercharging is required to reach the target average indicated pressure. At this time, the actual average indicated pressure of the engine after exiting the dynamic VVT quickly falls below the target average indicated pressure, causing the engine to meet the conditions for entering the dynamic VVT again and enter the dynamic VVT again, resulting in the engine frequently entering and exiting the dynamic VVT. When a vehicle is running in a low-altitude environment, the engine usually does not frequently enter and exit the dynamic VVT. Based on this, the present application sets different set pressure error margins for different set ambient pressure values.

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

[0106] It is understandable that the ambient pressure value of the vehicle in a high-altitude environment is usually lower. Therefore, when the present application determines that the set ambient pressure value is less than the ambient pressure threshold value, it can be determined that the vehicle is operating in a high-altitude environment.

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

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

[0109] The engine average indicated pressure threshold determined in this application cannot be set too small to avoid failure to exit dynamic VVT when the engine target average indicated pressure is low, thereby causing economic losses.

[0110] The value of the first pressure error amplitude is determined according to actual needs and can be 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 a high-altitude environment (low ambient pressure value) than in a low-altitude environment, to ensure that when the engine has a large torque demand, if the engine meets the dynamic VVT conditions and enters the dynamic VVT, it is not easy to exit the dynamic VVT, that is, the engine target average indicated pressure in the high-altitude environment is not easy to reach the set engine average indicated pressure threshold, and thus it is not easy to meet the conditions for exiting the dynamic VVT, so as to ensure the power of the engine in the high-altitude environment and avoid the problem of repeatedly entering and exiting the dynamic VVT.

[0112] The engine average indicated pressure threshold in Table 1 is set larger in a low altitude environment (high ambient pressure value) than in a high altitude environment, which can avoid normal exit of dynamic VVT in a low altitude environment (ie, a plain environment) to ensure economy.

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

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

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

[0116] (2) determining the sum of the mean indicated pressure test value and the second pressure error amplitude as the engine mean indicated pressure threshold;

[0117] Wherein, the set pressure error range includes: the second pressure error range.

[0118] When the vehicle is running in a low-altitude environment, the engine usually does not frequently enter and exit the dynamic VVT. In order to take into account both the power and economy of the vehicle, when the vehicle is running in a low-altitude environment, it only needs to ensure that the vehicle enters the dynamic VVT when there is a power demand (for example, the engine needs a large torque), and exit the dynamic VVT and return to the normal VVT when the engine power demand is met.

[0119] Based on this, the present 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 amplitude is determined according to actual needs and can be 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 indicated mean pressure, the engine speed is gradually accelerated from the engine speed lower limit according to different torque requirements.

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

[0124] (2) Under each of the set engine target indicated mean pressure and each of the engine speeds, determine the mean indicated pressure difference corresponding to when the torque difference between the actual engine torque and the engine target torque is less than a 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 (that is, when the actual engine torque is close to the engine target torque), the difference between the engine target average indicated pressure and the actual engine average indicated pressure is obtained as the average indicated pressure difference under this operating condition.

[0126] The difference threshold is used to characterize the 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, determining that the current engine load parameter satisfies the dynamic VVT exit critical value;

[0129] Controlling the engine to exit the dynamic VVT;

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

[0131] The dynamic VVT exit critical value includes: the target mean indicated pressure difference value obtained from Table 2, and the engine target mean indicated pressure threshold value obtained from Table 1.

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

[0133] (1) When the engine enters dynamic VVT, the present application obtains current engine load parameters (including: current engine target indicated mean pressure and current engine actual indicated mean pressure), current engine power parameters (including: current engine speed) and the current ambient pressure value in which the vehicle is running.

[0134] (2) According to the current engine speed and the current ambient pressure value, determine the corresponding engine target average indicated pressure threshold from Table 1.

[0135] (3) According to the current engine speed and the current engine target indicated mean pressure, determine the corresponding target indicated mean pressure difference from Table 2.

[0136] (4) Calculating a difference between a current engine target mean indicated pressure and a current engine actual mean indicated pressure. When the difference is less than the target mean indicated pressure difference and the current engine target mean indicated pressure is less than the engine target mean indicated pressure threshold, determining that the current engine load parameter satisfies the dynamic VVT exit critical value. At this time, controlling the engine to exit dynamic VVT.

[0137] In summary, the present application comprehensively considers the engine power parameters and the environmental pressure values ​​in which the engine is running when determining the conditions for exiting dynamic VVT, thereby ensuring that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT when the engine torque demand is large in high altitude areas, that is, it effectively avoids the situation where the output power is frequently interrupted when the engine has high power demand, thereby solving the problem of vehicle jerking caused by large fluctuations in vehicle torque.

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

[0139] In one embodiment, the present application also discloses a process of the engine entering dynamic VVT, which specifically includes:

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

[0141] Among them, the current operating condition information includes: engine target mean indicated pressure, engine actual mean indicated pressure, accelerator pedal opening, target air-fuel ratio and engine speed.

[0142] (2) When the current operating condition information satisfies a condition for entering dynamic VVT, controlling the engine to enter the dynamic VVT.

[0143] Specifically, the engine enters the dynamic VVT condition as follows:

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

[0145] The accelerator pedal opening is greater than 0%;

[0146] Target air-gas>b;

[0147] Engine speed <c.

[0148] In practical applications, the values ​​of a, b and c can be determined according to actual conditions. For example, the value 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 the engine to enter dynamic VVT include:

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

[0151] The engine exit dynamic VVT conditions include:

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

[0153] To avoid the situation where the engine frequently enters and exits dynamic VVT when the vehicle is operating in a high-altitude environment, in this application, at the same engine speed and target average indicated pressure, the value of d is less than the value of a.

[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 obtained is less than the difference threshold (that is, 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 obtained at each set engine target average indicated pressure and each engine speed is greater than the target difference threshold (that is, the difference between the actual engine torque and the engine target torque is large).

[0156] This application avoids the engine from frequently entering and exiting dynamic VVT by setting a sufficient difference between the a value when the engine enters dynamic VVT and the d value when the engine exits dynamic VVT.

[0157] The value of a can be found in Table 3.

[0158] Table 3

[0159]

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

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

[0162] See also Figure 2 , a schematic diagram of the structure of an engine control device disclosed in an embodiment of the present invention, the device is applied to an engine controller, and the device may include:

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

[0164] Preferably, the engine in the present application may 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] The target engine indicated mean pressure refers to the desired indicated mean pressure of the engine.

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

[0168] (1) For hybrid vehicles, the target indicated mean pressure of the engine is obtained based on the engine demand torque.

[0169] Among them, the specific process of obtaining the target average indicated pressure of the engine according to the engine demand torque can be referred to the existing scheme, which will not be repeated here.

[0170] (2) For fuel vehicles, the corresponding engine demand torque is first determined based on the accelerator pedal opening, and then the engine target average indicated pressure is obtained based on the engine demand torque.

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

[0172] In this application, when the engine has a power demand and enters dynamic VVT, the engine controller will obtain the engine load parameters, engine power parameters and the environmental pressure value of the engine operation at each moment in real time.

[0173] In practical applications, it can be determined whether the environment in which the engine is located is a high-altitude environment or a low-altitude environment according to the current environmental pressure value in which the engine is running.

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

[0175] This application determines the critical value of exiting dynamic VVT that satisfies the corresponding engine operating condition based on the real-time engine power parameters and the environmental pressure value in which the engine is running. That is, under different engine power parameters and environmental pressure values ​​in this application, the corresponding critical value of exiting dynamic VVT is different.

[0176] The exit control unit 203 is used to control the engine to exit the dynamic VVT when the current engine load parameter and the dynamic VVT exit critical value meet the dynamic VVT exit condition.

[0177] It should be noted that the critical value for exiting dynamic VVT includes multiple critical values, and different engine load parameters correspond to different critical values.

[0178] In summary, the present application discloses an engine control device, which obtains the current engine load parameter, the current engine power parameter and the current environmental pressure value in which the engine is running when the engine enters dynamic VVT, determines the critical value for exiting dynamic VVT that satisfies the current engine working condition based on the current engine power parameter and the current environmental pressure value, and controls the engine to exit dynamic VVT when the current engine load parameter and the critical value for exiting dynamic VVT meet the conditions for exiting dynamic VVT. When determining the conditions for exiting dynamic VVT, the present application comprehensively considers the engine power parameter and the environmental pressure value in which the engine is running, so as to ensure that the conditions for exiting dynamic VVT meet the operating environment and power requirements of the engine. Therefore, after the engine enters dynamic VVT, it can effectively avoid the situation where the engine frequently enters and exits dynamic VVT when the engine torque demand is large in high altitude areas, that is, it effectively avoids the situation where the output power is frequently interrupted when the engine has high power demand, thereby solving the problem of vehicle jerking caused by large-scale fluctuations in vehicle torque.

[0179] In one embodiment, the critical value determination unit 202 may be specifically configured to:

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

[0181] a pressure difference determination subunit, for determining a target mean indicated pressure difference corresponding to the current engine speed and the current engine target mean indicated pressure from the set corresponding relationship between the engine speed, the engine target mean indicated pressure and the mean indicated pressure difference, wherein the current engine load parameter includes: the current engine target mean indicated pressure;

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

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

[0184] Turning off the dynamic VVT function of the engine;

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

[0186] The engine mean indicated pressure threshold is determined based on the mean indicated pressure test value and a set pressure error margin.

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

[0188] Determining whether the set environmental pressure value is less than an environmental pressure dividing value, wherein the environmental pressure dividing value is used to divide a high altitude environment and a low altitude environment;

[0189] If the set environmental pressure value is less than the environmental pressure threshold value, determining that the vehicle is operating in the high altitude environment;

[0190] Determine the difference between the average indicated pressure test value and the first pressure error amplitude as the engine average indicated pressure threshold;

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

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

[0193] If the set environmental pressure value is not less than the environmental pressure threshold value, determining that the vehicle is operating in the low altitude environment;

[0194] Determine the sum of the mean indicated pressure test value and the second pressure error amplitude as the engine mean indicated pressure threshold;

[0195] Wherein, the set pressure error range includes: the second pressure error range.

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

[0197] When the vehicle is running on the test road, for each set engine target indicated mean pressure, the engine speed is gradually accelerated from the engine speed lower limit value according to different torque requirements;

[0198] Under each of the set engine target indicated mean pressure and each of the engine speeds, the mean indicated pressure difference corresponding to when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold is determined.

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

[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, determining that the current engine load parameter satisfies the dynamic VVT exit critical value;

[0201] Controlling the engine to exit the dynamic VVT;

[0202] Wherein, the current engine load parameter includes: the current engine target mean indicated pressure and the current engine actual mean indicated pressure;

[0203] The dynamic VVT exit critical value includes: the target indicated mean pressure difference value and the engine target indicated mean pressure threshold value.

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

[0205] Dynamic VVT entry unit for:

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

[0207] When the current operating condition information satisfies a condition for entering dynamic VVT, controlling the engine to enter the dynamic VVT;

[0208] The current operating condition information includes: engine target mean indicated pressure, engine actual mean indicated pressure, accelerator 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 part of the method embodiment, which will not be repeated here.

[0210] Corresponding to the above embodiment, see Figure 3 , a schematic diagram of the structure of an engine controller in a vehicle disclosed in an embodiment of the present invention, the engine controller may include: a processor 1 and a memory 2;

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

[0212] Processor 1, configured to execute at least one instruction;

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

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

[0215] The memory 2 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

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

[0217] Corresponding to the above embodiment, the present invention further discloses a computer storage medium, which stores at least one instruction, and when the at least one instruction is executed by a processor, the steps shown in the engine control method embodiment are implemented.

[0218] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[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 enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather 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, the current engine load parameter, the current engine power parameter and the current environmental pressure value under which the vehicle is running are obtained; Determining a critical value for exiting dynamic VVT that satisfies a current engine operating condition based on the current engine power parameter and the current ambient pressure value; When the current engine load parameter and the dynamic VVT exit threshold value satisfy a dynamic VVT exit condition, the engine is controlled to exit the dynamic VVT.

2. The engine control method according to claim 1, characterized in that: The step of determining a critical value for exiting dynamic VVT that satisfies a current engine operating condition based on the current engine power parameter and the current ambient pressure value includes: Determining the target engine mean indicated pressure threshold corresponding to the current engine speed and the current ambient pressure value from the set corresponding relationship between the engine speed, the ambient pressure value and the engine mean indicated pressure threshold, wherein the current engine power parameter includes: the current engine speed; Determining the target mean indicated pressure difference corresponding to the current engine speed and the current engine target mean indicated pressure from the set corresponding relationship between the engine speed, the engine target mean indicated pressure and the mean indicated pressure difference, wherein the current engine load parameter includes: the current engine target mean indicated pressure; The engine target indicated mean pressure threshold and the target indicated mean pressure difference are determined as the dynamic VVT exit critical value.

3. The engine control method according to claim 2, characterized in that: The process of determining the engine indicated mean pressure threshold comprises: Turning off the dynamic VVT function of the engine; When the vehicle is running on the test road, for each set ambient pressure value condition, the engine speed is gradually accelerated from the lower limit of the engine speed according to different torque requirements to obtain the value that the actual average indicated pressure of the engine can reach at different engine target average indicated pressures under the set ambient pressure value, and the value that the actual average indicated pressure of the engine can reach is used as the average indicated pressure test value; The engine mean indicated pressure threshold is determined based on the mean indicated pressure test value and a set pressure error margin.

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

5. The engine control method according to claim 4, characterized in that: Also includes: If the set environmental pressure value is not less than the environmental pressure threshold value, determining that the vehicle is operating in the low altitude environment; Determine the sum of the mean indicated pressure test value and the second pressure error amplitude as the engine mean indicated pressure threshold; Wherein, the set pressure error range includes: the second pressure error range.

6. The engine control method according to claim 2, characterized in that: The process of determining the mean indicated pressure difference comprises: When the vehicle is running on the test road, for each set engine target indicated mean pressure, the engine speed is gradually accelerated from the engine speed lower limit value according to different torque requirements; Under each of the set engine target indicated mean pressure and each of the engine speeds, the mean indicated pressure difference corresponding to when the torque difference between the actual engine torque and the engine target torque is less than a difference threshold is determined.

7. The engine control method according to any one of claims 1 to 6, characterized in that: When the current engine load parameter and the critical value for exiting dynamic VVT satisfy a condition for exiting dynamic VVT, controlling the engine to exit the dynamic VVT comprises: 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, determining that the current engine load parameter satisfies the dynamic VVT exit critical value; Controlling the engine to exit the dynamic VVT; Wherein, the current engine load parameter includes: the current engine target mean indicated pressure and the current engine actual mean indicated pressure; The dynamic VVT exit critical value includes: the target indicated mean pressure difference value and the engine target indicated mean pressure threshold value.

8. The engine control method according to claim 1, characterized in that: The process of the engine entering the dynamic VVT includes: Acquiring current operating condition information of the engine; When the current operating condition information satisfies a condition for entering dynamic VVT, controlling the engine to enter the dynamic VVT; The current operating condition information includes: engine target mean indicated pressure, engine actual mean indicated pressure, accelerator pedal opening, target air-fuel ratio and engine speed.

9. An engine control device, characterized in that: include: An acquisition unit, used for acquiring a current engine load parameter, a current engine power parameter, and a current environmental pressure value in which the vehicle is running when the engine enters dynamic VVT; a critical value determination unit, configured to determine a critical value for exiting dynamic VVT that satisfies a current engine operating condition based on the current engine power parameter and the current ambient pressure value; An exit control unit is used to control the engine to exit the dynamic VVT when the current engine load parameter and the dynamic VVT exit critical value meet the dynamic VVT exit condition.

10. 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 according to any one of claims 1 to 7.

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