Method, device and equipment for controlling opening degree of mixing valve and medium

Abstract

The invention discloses a mixing valve opening degree control method, device and equipment and a medium, and the method comprises the steps that when a mixing valve is in a transition working condition from full opening to non-full opening, the current mixing valve opening degree and the mixing valve opening degree change rate are obtained; determining the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determining a mixing valve opening change rate correction coefficient and locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for keeping the current opening degree of the mixing valve unchanged; after the locking time is over, the mixing valve opening degree change rate is corrected based on the mixing valve opening degree change rate correction coefficient, and the final mixing valve opening degree change rate is obtained; and based on the current mixing valve opening and the final mixing valve opening change rate, the mixing valve control opening is determined. According to the method, the change rate of the opening degree of the mixing valve is controlled and optimized from the angle of improving the boost pressure control precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine control, and in particular relates to a method, device, equipment and medium for controlling the opening of a mixing valve for improving the control accuracy of boost pressure. Background Art

[0002] Exhaust gas recirculation (EGR) is the process of taking exhaust gas from the exhaust and re-entering the intake system. Studies have shown that the EGR system has certain advantages in improving emissions, reducing fuel consumption and improving anti-knock capabilities. In the low-pressure EGR system, the control optimization of the mixing valve is particularly effective in improving EGR.

[0003] For example, the patent with application number CN202011247319.6 discloses a method and system for calculating the target EGR rate, which determines the basic target EGR rate based on the engine speed and load; obtains the corresponding correction rate based on the special working conditions; determines the initial target EGR rate based on the basic target EGR rate and each correction rate; determines whether EGR is activated based on the EGR activation state condition; divides the EGR state according to the judgment result, and determines the final target EGR rate. This patent calculates the initial target EGR rate from the throttle opening, manifold pressure difference and minimum ignition angle, can accurately calculate the target EGR rate, and introduces the EGR control activation condition to perform a secondary correction on the final target EGR rate. However, this patent does not take into account the control accuracy of the target opening of the mixing valve.

[0004] Therefore, it is necessary to consider the control accuracy in the process of the mixing valve changing from fully open to partially open, optimize the mixing valve opening change rate, and improve the control stability. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a mixing valve opening control method, device, equipment and medium for improving the boost pressure control accuracy, thereby solving the control stability problem of the mixing valve from fully open to partially open.

[0006] To achieve the above object, according to a first aspect of the present invention, a method for controlling the opening of a mixing valve for improving the control accuracy of boost pressure is provided, the method comprising:

[0007] When the mixing valve is in a transitional operating state from fully open to partially open, the current mixing valve opening and the mixing valve opening change rate are obtained;

[0008] Determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the mixing valve opening change rate correction coefficient and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for maintaining the current mixing valve opening unchanged;

[0009] After the locking time is over, the mixing valve opening rate is corrected based on the mixing valve opening rate correction coefficient to obtain a final mixing valve opening rate change;

[0010] The mixing valve control opening is determined based on the current mixing valve opening and the final mixing valve opening change rate.

[0011] In the above scheme, the mixing valve opening change rate correction coefficient and the locking time are determined based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, including:

[0012] If the ratio of the current target boost pressure to the maximum boost pressure is greater than the first preset value, the lock time is calibrated according to the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, and the mixing valve opening change rate correction coefficient is set to 1;

[0013] If the ratio of the current target boost pressure to the minimum boost pressure is less than the second preset value, the lock time is set to 0, and the mixing valve opening change rate correction coefficient is set to a third preset value;

[0014] In other cases, the lock time is set to 0, and the mixing valve opening rate change correction coefficient is determined based on the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, the ratio of the current target boost pressure to the maximum boost pressure, and the ratio of the current target boost pressure to the minimum boost pressure.

[0015] In the above scheme, the lock time is calibrated according to the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, including:

[0016] After calibration, ensure that the difference between the target boost pressure and the actual boost pressure after the mixing valve exits full opening is within the preset range, and that the fluctuation range of the target boost pressure and the actual boost pressure is within the preset range;

[0017] Among them, the first preset value is 0.95, the second preset value is 1.02, and the third preset value is 1.15.

[0018] In the above scheme, the mixing valve opening change rate correction coefficient is determined based on the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, the ratio of the current target boost pressure to the maximum boost pressure, and the ratio of the current target boost pressure to the minimum boost pressure, including:

[0019]

[0020] Among them, r2 is the correction coefficient of the mixing valve opening rate change, The ratio of the current actual boost pressure to the current target boost pressure and the correction factor determined by the engine speed n, is the ratio of the current target boost pressure to the maximum boost pressure Determine the correction factor, is the ratio of the current target boost pressure to the minimum boost pressure Determine the correction factor.

[0021] In the above scheme, the method for determining each correction coefficient in the calculation formula of the correction coefficient of the mixing valve opening rate is as follows:

[0022] Ratio of current target boost pressure to maximum boost pressure at different engine speeds n Not greater than 0.5, the ratio of the current target boost pressure to the minimum boost pressure When it is not less than 1.2, the ratio of the current actual boost pressure to the current target boost pressure is adjusted. Get the correction factor Ensure that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from fully open to partially open of the mixing valve is within the preset range does not exceed a first preset time;

[0023] At the same time, the fluctuation of engine speed n and the ratio of current actual boost pressure to current target boost pressure When the fluctuations do not exceed the respective preset fluctuation ranges, the mixing valve opening change rate correction coefficient r2 is not updated;

[0024] In determining the correction factor Then, the engine speed n is fixed at different speeds, and the ratio of the current target boost pressure to the maximum boost pressure is tested. Greater than 0.5 and less than 0.95, the ratio of the current target boost pressure to the minimum boost pressure When it is not less than 1.2, adjust the ratio of the current target boost pressure to the maximum boost pressure To determine the correction factor To also ensure that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from fully open to partially open of the mixing valve is within the preset range does not exceed a first preset time;

[0025] In determining the correction factor and correction factor Then, the engine speed n is fixed at different speeds, and the ratio of the current target boost pressure to the maximum boost pressure is tested. Not greater than 0.5, the ratio of the current target boost pressure to the minimum boost pressure When it is less than 1.2 and not less than 1.02, adjust the ratio of the current target boost pressure to the minimum boost pressure To determine the correction factor This also ensures that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from full opening to partly full opening of the mixing valve is within the preset range does not exceed the first preset time.

[0026] In the above scheme, the mixing valve opening rate is corrected based on the mixing valve opening rate correction coefficient to obtain the final mixing valve opening rate change, including:

[0027] dpct MGVNew =dpct MGVRaw ×r2×(1+r Adapt )

[0028] Among them, dpct MGVNew is the final mixing valve opening change rate, dpct MGVRaw is the mixing valve opening change rate, r2 is the mixing valve opening change rate correction coefficient, r Adapt To learn the update coefficients.

[0029] In the above scheme, the activation conditions for learning update coefficients include:

[0030] The mixing valve is in the transition process from fully open to partially open;

[0031] The supercharger is in the closed-loop control active state;

[0032] The absolute value of the engine target intake pressure change rate does not exceed the preset change rate value;

[0033] The engine mileage corresponding to the learning update coefficient not being updated exceeds the preset mileage value;

[0034] When the above conditions are met at the same time, the activation condition of the learning update coefficient is met, and the learning update coefficient is updated at this time.

[0035] In the above scheme, the updating method of the learning update coefficient includes:

[0036] In the first case, if:

[0037] The continuous time during which the difference between the target boost pressure and the actual boost pressure exceeds the preset first difference value exceeds the second preset time;

[0038] The difference between the target EGR rate and the actual EGR rate does not exceed a first preset difference range;

[0039] The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range;

[0040] dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference;

[0041] Then: r Adapt =rAdapt (z)-0.1; where r Adapt (z) is the learning update coefficient obtained from the last learning;

[0042] In the second case, if:

[0043] The continuous time during which the difference between the target boost pressure and the actual boost pressure does not exceed the preset first difference value exceeds a second preset time;

[0044] The difference between the target EGR rate and the actual EGR rate does not exceed a first preset difference range;

[0045] The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range;

[0046] dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference;

[0047] Then: r Adapt =r Adapt (z)+0.08;

[0048] The third case, if:

[0049] The continuous time during which the difference between the target boost pressure and the actual boost pressure exceeds the preset first difference value exceeds the second preset time;

[0050] The difference between the target EGR rate and the actual EGR rate exceeds the first preset difference range for a continuous period exceeding a second preset time;

[0051] The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range;

[0052] dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference;

[0053] Then: r Adapt =r Adapt (z) -0.03;

[0054] The fourth case, if:

[0055] The continuous time during which the difference between the target boost pressure and the actual boost pressure does not exceed the preset first difference value exceeds a second preset time;

[0056] The difference between the target EGR rate and the actual EGR rate exceeds the first preset difference range for a continuous period exceeding a second preset time;

[0057] The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range;

[0058] dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference;

[0059] Then: r Adapt =r Adapt (z)+0.02;

[0060] In other cases, r Adapt =r Adapt (z);

[0061] If the learning update coefficient has been updated once in this driving cycle, the learning update coefficient will not be updated again in this driving cycle.

[0062] According to a second aspect of the present invention, there is provided a mixing valve opening control device for improving boost pressure control accuracy, comprising:

[0063] An acquisition unit, used for acquiring the current mixing valve opening and the mixing valve opening change rate when the mixing valve is in a transitional operating condition from fully open to not fully open;

[0064] The intermediate unit is used to determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the mixing valve opening change rate correction coefficient and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for maintaining the current mixing valve opening unchanged;

[0065] A correction unit, used for correcting the mixing valve opening rate change rate based on the mixing valve opening rate change rate correction coefficient after the locking time ends, to obtain a final mixing valve opening rate change rate;

[0066] The determination unit is used to determine the mixing valve control opening based on the current mixing valve opening and the final mixing valve opening change rate.

[0067] According to a third aspect of the present invention, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the mixing valve opening control method for improving the boost pressure control accuracy as described above are implemented.

[0068] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the mixing valve opening control method for improving boost pressure control accuracy as described in any one of the above are implemented.

[0069] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0070] The present invention determines the mixing valve change rate correction coefficient and the locking time based on the boost pressure limit, the target boost pressure and the actual boost pressure difference. After the locking time ends, the mixing valve opening change rate is corrected based on the mixing valve opening change rate correction coefficient, and the mixing valve opening change rate is controlled and optimized from the perspective of improving the boost pressure control accuracy.

[0071] In addition, when determining the final rate of change of the mixing valve opening, a learning update coefficient is introduced. Through the self-learning update of the learning update coefficient, the boost pressure responsiveness can be improved, the intake pressure responsiveness overshoot can be avoided, the boost pressure responsiveness can be avoided to be too poor, or the boost pressure responsiveness can be avoided to be too aggressive, thereby improving the control stability of the mixing valve from fully open to not fully open. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 A flow chart of a mixing valve opening control method for improving boost pressure control accuracy provided by an embodiment of the present invention;

[0073] Figure 2 A schematic diagram of the structure of a low-pressure EGR system provided in an embodiment of the present invention;

[0074] Figure 3 A flow chart for determining a mixing valve opening change rate correction coefficient and a locking time provided by an embodiment of the present invention;

[0075] Figure 4 A schematic diagram of a mixing valve opening control device for improving boost pressure control accuracy provided by an embodiment of the present invention;

[0076] Figure 5 A schematic diagram of the structure of a computer device provided in an embodiment of the present invention.

[0077] In the figure: 1-air filter, 2-mixing valve, 3-supercharger compressor, 4-throttle, 5-engine, 6-supercharger turbine, 7-catalyst, 8-particulate matter trap, 9-EGR cooler, 10-EGR valve, 11-EGR temperature sensor, 12-EGR differential pressure sensor. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0079] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0081] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0083] The present invention optimizes the mixing valve opening change rate from the perspective of control stability during the mixing valve changing from fully open to partially fully open.

[0084] like Figure 2As shown, the low-pressure EGR system includes: an air filter 1, a mixing valve 2, a supercharger compressor 3, a throttle valve 4, an engine 5, a supercharger turbine 6, a catalyst 7, a particulate matter trap 8, an EGR cooler 9, an EGR valve 10, an EGR temperature sensor 11, and an EGR differential pressure sensor 12.

[0085] The supercharger compressor 3 compresses fresh air for supercharging; the supercharger turbine 6 controls the working efficiency of the turbine by controlling the opening of the supercharger's exhaust bypass valve, thereby achieving different supercharging capabilities; compared with the non-low-pressure EGR system, the low-pressure EGR system has the following additional components: EGR cooler 9, EGR temperature sensor 11, EGR valve 10, EGR pressure difference sensor 12, and mixing valve 2; the mixing valve 2 is used to adjust the pressure at the outlet of the EGR valve 10, increase the pressure difference at both ends of the EGR valve 10, and increase the EGR rate; the EGR cooler 9 is used to cool the exhaust gas to increase the exhaust gas flow rate and reduce the exhaust gas temperature; the EGR valve 10 has a throttling effect to control the exhaust gas flow rate entering the cylinder; the EGR temperature sensor 11 is used to detect the exhaust gas temperature entering the EGR valve; the EGR pressure difference sensor 12 is used to detect the pressure at the EGR inlet and outlet.

[0086] The purpose of the present invention is to propose a method for controlling the opening of a mixing valve that improves the control accuracy of boost pressure, so as to solve problems such as control stability in the process. Patent CN202110184826.8 "Method for determining the target opening of a mixing valve in an EGR system" and patent CN202110184815.X "Method for determining the activation state of a mixing valve in a low-pressure EGR system" both mention transition control in the process of the mixing valve changing from fully open (non-activated state) to non-fully open (activated), and determine the rate of change of the target opening of the mixing valve and the shortest time for the mixing valve to be non-fully open. The present invention optimizes the rate of change of the target opening of the mixing valve when the mixing valve requests to enter the non-fully open process, so as to further improve the control stability problem in the control process.

[0087] like Figure 1 As shown, the mixing valve opening control method for improving boost pressure control accuracy according to an embodiment of the present invention comprises the following steps:

[0088] S1. When the mixing valve is in a transitional operating condition from fully open to partially open, the current mixing valve opening and the mixing valve opening change rate are obtained.

[0089] Assume that based on the current public technology, the current mixing valve is in a transitional state from fully open to partially open, and the current mixing valve opening is pct MGVRaw , and the rate of change is dpct MGVRaw .

[0090] S2. Determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the correction coefficient of the mixing valve opening rate and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time to maintain the current mixing valve opening unchanged.

[0091] Based on the maximum boost pressure, the minimum boost pressure (the description of the maximum boost pressure and the minimum boost pressure can be seen in patent CN202311487573.7 "A boost pressure control method") and the current target boost pressure (the target boost pressure can be seen in patent CN202010109549.X "Method for determining target boost pressure of an exhaust gas turbocharger engine, storage medium"), and the actual boost pressure, the mixing valve opening change rate correction coefficient r2 and the locking time t1 are determined, where the locking time t1 refers to the time to maintain the current mixing valve opening unchanged (of course, the mixing valve opening change rate correction coefficient that affects the change of the mixing valve opening in other cases still works). After the locking time t1 ends, the mixing valve opening rate is corrected based on the mixing valve opening rate change correction coefficient r2.

[0092] like Figure 3 As shown, the specific steps are as follows:

[0093] S201, the ratio of the current target boost pressure to the maximum boost pressure When it is greater than the preset value, which is 0.95 in this example, the lock time t1 depends on At the same time, the mixing valve target opening rate change correction coefficient r2 is set to 1 to meet the boost pressure requirements, achieve boost control stability, and meet the vehicle power requirements. BoostAct is the actual boost pressure.

[0094] The calibration method is: 1) ensure that the difference between the target boost pressure and the actual boost pressure is controlled within ±2kPa, 2) at the same time, when the target boost pressure fluctuation range is within ±2kPa, the actual boost pressure fluctuation range is also within ±2kPa.

[0095] S202: Ratio of current target boost pressure to minimum boost pressure When it is less than the preset value, which is 1.02 in this example, the locking time t1 is 0, and the correction coefficient r2 of the target opening rate of the mixing valve is set to 1.15, so as to quickly reduce the boost pressure and improve the vehicle dynamics.

[0096] S203. In other cases, t1 is equal to 0, and:

[0097]

[0098] in, Based on and the correction factor determined by the engine speed n, Based on Determine the correction factor, Based on Determine the correction factor.

[0099] In pressure ratio The smaller the ratio, the slower the boost pressure control response. In order to improve the boost pressure control accuracy, it is necessary to reduce the mixing valve opening change rate, thereby increasing the gas flow entering the supercharger compressor, improving the boost capacity, and thus increasing the actual boost pressure. If it is too large, it means that the boost pressure control response is too fast. In order to improve the boost pressure control accuracy, the mixing valve opening change rate is increased to reduce the gas flow entering the supercharger compressor as soon as possible, reduce the boost capacity, and thus reduce the actual boost pressure. In this example, at different engine speeds n, Not more than 0.5, When it is not less than 1.2, by adjusting different pressure ratios Get Ensure that during the transition from fully open to partially open mixing valve, the difference between the target boost pressure and the actual boost pressure is controlled within ±2kPa for no more than 0.5s.

[0100] Likewise, in order to avoid the engine speed n and Too frequent fluctuations lead to If the adjustment changes too much, resulting in too large a change in the correction coefficient r2, the mixing valve opening control fluctuates too much, resulting in poor mixing valve control stability, then the following treatment is performed:

[0101] The engine speed fluctuation n (the difference between the engine speed in this sampling period and the engine speed in the previous sampling period, the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±40rpm) and Fluctuation (pressure ratio in this sampling period The pressure ratio of the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.15 in this example), the correction coefficient r2 is not updated.

[0102] In the calibration Then, different engine speeds n are fixed and tested. Greater than 0.5 and not greater than 0.95, When it is not less than 1.2, adjust To determine This also ensures that during the transition from fully open to partially open mixing valve, the difference between the target boost pressure and the actual boost pressure is controlled within ±2kPa for no more than 0.5s.

[0103] In the calibration and Then, different engine speeds n are fixed and tested. Not more than 0.5, When it is less than 1.2 and not less than 1.02, adjust To determine This also ensures that during the transition from fully open to partially open mixing valve, the difference between the target boost pressure and the actual boost pressure is controlled within ±2kPa for no more than 0.5s.

[0104] S3. After the locking time ends, the mixing valve opening rate of change is corrected based on the mixing valve opening rate of change correction coefficient to obtain a final mixing valve opening rate of change.

[0105] In the transition process from fully open to partially open, the final mixing valve opening change rate dpct MGVNew :

[0106] dpct MGVNew =dpct MGVRaw ×r2×(1+r Adapt )

[0107] Among them, r Adapt To learn the update coefficient, its default value is 0 and can be saved after the vehicle is powered off.

[0108] In order to improve the boost pressure responsiveness and EGR rate response accuracy during the control process, the update method can only be activated when the following conditions are met at the same time:

[0109] (1) The mixing valve is in the transition process from fully open to partially open;

[0110] (2) The supercharger is in the closed-loop control activation state;

[0111] (3) The absolute value of the engine target intake pressure change rate does not exceed a preset value, which is 2 kPa / 10 ms in this example;

[0112] (4) The engine mileage corresponding to the failure to update the learning coefficient exceeds a preset value, which in this example is 20,000 kilometers.

[0113] When the above conditions are met at the same time, then:

[0114] In the first case, the boost pressure response is poor, but the EGR rate response is good:

[0115] 1) The difference between the target boost pressure and the actual boost pressure exceeds the preset value (in this example, 5 kPa) for a continuous period of more than 0.1 s

[0116] 2) The difference between the target EGR rate and the actual EGR rate does not exceed the preset value ±0.1;

[0117] 3) The difference between the target mixing valve opening and the actual mixing valve opening shall not exceed the preset value (in this example, ±1%);

[0118] 4)dpct MGVNew -dpct MGVRaw The value does not exceed the preset value. In this example, -15% / 10ms is used.

[0119] Improve boost pressure responsiveness:

[0120] r Adapt =r Adapt (z)-0.1, where r Adapt (z) is the self-learning correction coefficient obtained from the last learning.

[0121] In the second case, the boost pressure response is too aggressive, but the EGR rate response is good:

[0122] 1) The difference between the target boost pressure and the actual boost pressure is less than the preset value. In this example, the continuous time of -5kPa exceeds 0.1s.

[0123] 2) The difference between the target EGR rate and the actual EGR rate does not exceed the preset value ±0.1;

[0124] 3) The difference between the target mixing valve opening and the actual mixing valve opening shall not exceed the preset value (in this example, ±1%);

[0125] 4)dpct MGVNew -dpct MGVRaw The value does not exceed the preset value. In this example, -15% / 10ms is used.

[0126] To avoid excessive overshoot of intake pressure response:

[0127] r Adapt =r Adapt (z)+0.08.

[0128] In the third case, the boost pressure responsiveness is poor and the EGR rate responsiveness is poor:

[0129] 1) The difference between the target boost pressure and the actual boost pressure is greater than the preset value (5 kPa in this example) for a continuous period of more than 0.1 s;

[0130] 2) The difference between the target EGR rate and the actual EGR rate exceeds the preset value ±0.15 for more than 0.1s continuously;

[0131] 3) The difference between the target mixing valve opening and the actual mixing valve opening shall not exceed the preset value (in this example, ±1%);

[0132] 4)dpct MGVNew -dpct MGVRaw The value does not exceed the preset value. In this example, -15% / 10ms is used.

[0133] Then appropriately adjust the mixing valve full opening rate to avoid poor boost pressure responsiveness:

[0134] r Adapt =r Adapt (z)-0.03.

[0135] In the fourth case, the boost pressure response is too aggressive, but the EGR rate response is poor:

[0136] 1) The difference between the target boost pressure and the actual boost pressure is less than the preset value (in this example, -5 kPa) for a continuous period of more than 0.1 s;

[0137] 2) The difference between the target EGR rate and the actual EGR rate exceeds the preset value ±0.15 for more than 0.1s continuously;

[0138] 3) The difference between the target mixing valve opening and the actual mixing valve opening shall not exceed the preset value (in this example, ±1%);

[0139] 4)dpct MGVNew -dpct MGVRaw The value does not exceed the preset value. In this example, -15% / 10ms is used.

[0140] Then adjust the mixing valve full opening rate appropriately to avoid overly aggressive boost pressure response:

[0141] r Adapt =r Adapt (z)+0.02

[0142] In other cases, r Adapt =r Adapt (z).

[0143] If the learning coefficient is updated, it will not be updated in this driving cycle.

[0144] S4. Determine the mixing valve control opening based on the current mixing valve opening and the final mixing valve opening change rate.

[0145] Finally, the action behavior of the mixing valve is determined based on the target opening of the mixing valve and the optimized changing rate of the mixing valve opening.

[0146] The above completes the entire description of the control method of the mixing valve from fully open to partially open.

[0147] The mixing valve opening control device for improving the boost pressure control accuracy based on the above-mentioned embodiment is as follows: Figure 4 As shown, including:

[0148] The acquisition unit 501 is used to acquire the current mixing valve opening and the mixing valve opening change rate when the mixing valve is in a transitional operating state from fully open to partially open;

[0149] The intermediate unit 502 is used to determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the mixing valve opening change rate correction coefficient and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for maintaining the current mixing valve opening unchanged;

[0150] A correction unit 503, configured to correct the mixing valve opening change rate based on the mixing valve opening change rate correction coefficient after the locking time ends, to obtain a final mixing valve opening change rate;

[0151] The determination unit 504 is used to determine the mixing valve control opening based on the current mixing valve opening and the final mixing valve opening change rate.

[0152] like Figure 5 The figure is a schematic diagram of the structure of a computer device provided by an embodiment of the present invention, such as a smart phone, tablet computer, laptop computer, desktop computer, rack server, blade server, tower server or cabinet server (including an independent server, or a server cluster composed of multiple servers) that can execute programs. The computer device 20 of this embodiment includes at least but is not limited to: a memory 21 and a processor 22 that can communicate with each other via a system bus, such as Figure 5 It should be pointed out that Figure 5 Only computer device 20 is shown with components 21 - 22 , but it should be understood that implementing all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0153] In this embodiment, the memory 21 (i.e., readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM). The memory 21 can also be an external storage device of the computer device 20, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the computer device 20. Of course, the memory 21 can also include both the internal storage unit of the computer device 20 and its external storage device. In this embodiment, the memory 21 is generally used to store the operating system and various application software installed in the computer device 20, such as the program code of the mixing valve opening control method for improving the boost pressure control accuracy in the method embodiment. In addition, the memory 21 can also be used to temporarily store various data that have been output or are to be output.

[0154] The processor 22 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor 22 is generally used to control the overall operation of the computer device 20. In this embodiment, the processor 22 is used to run the program code stored in the memory 21 or process data, such as running a device storing a program code of a mixing valve opening control method for improving boost pressure control accuracy, so as to implement the mixing valve opening control method for improving boost pressure control accuracy in the method embodiment.

[0155] The present application also provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a disk, an optical disk, a server, an App application store, etc., on which a computer program is stored, and the program realizes the corresponding function when executed by the processor. The computer-readable storage medium of this embodiment is used to store the program code of the mixing valve opening control method for improving the boost pressure control accuracy, and when executed by the processor, the mixing valve opening control method for improving the boost pressure control accuracy of the method embodiment is realized.

[0156] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0157] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0158] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0159] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0160] In summary, the present invention proposes a mixing valve opening control method, device, equipment and medium for improving the boost pressure control accuracy. The method determines the mixing valve change rate correction coefficient and the locking time based on the boost pressure limit, the target boost pressure and the actual boost pressure difference. After the locking time ends, the mixing valve opening change rate is corrected based on the mixing valve opening change rate correction coefficient, and the mixing valve opening change rate is controlled and optimized from the perspective of improving the boost pressure control accuracy.

[0161] It should be noted that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0162] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0163] It will be easily understood by those skilled in the art that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the opening of a mixing valve to improve the control accuracy of boost pressure, characterized in that: The method includes: When the mixing valve is in a transitional operating state from fully open to partially open, the current mixing valve opening and the mixing valve opening change rate are obtained; Determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the mixing valve opening change rate correction coefficient and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for maintaining the current mixing valve opening unchanged; After the locking time is over, the mixing valve opening rate is corrected based on the mixing valve opening rate correction coefficient to obtain a final mixing valve opening rate change; The mixing valve control opening is determined based on the current mixing valve opening and the final mixing valve opening change rate.

2. The mixing valve opening control method for improving boost pressure control accuracy according to claim 1, characterized in that: The mixing valve opening change rate correction coefficient and the locking time are determined based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure, and the current actual boost pressure, including: If the ratio of the current target boost pressure to the maximum boost pressure is greater than the first preset value, the lock time is calibrated according to the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, and the mixing valve opening change rate correction coefficient is set to 1; If the ratio of the current target boost pressure to the minimum boost pressure is less than the second preset value, the lock time is set to 0, and the mixing valve opening change rate correction coefficient is set to a third preset value; In other cases, the lock time is set to 0, and the mixing valve opening rate change correction coefficient is determined based on the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, the ratio of the current target boost pressure to the maximum boost pressure, and the ratio of the current target boost pressure to the minimum boost pressure.

3. The mixing valve opening control method for improving boost pressure control accuracy according to claim 2, characterized in that: The lock time is calibrated according to the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, including: After calibration, ensure that the difference between the target boost pressure and the actual boost pressure after the mixing valve exits full opening is within the preset range, and at the same time, the fluctuation range of the target boost pressure and the actual boost pressure is within the preset range.

4. The mixing valve opening control method for improving boost pressure control accuracy according to claim 2, characterized in that: The first preset value is 0.95, the second preset value is 1.02, and the third preset value is 1.

15.

5. The mixing valve opening control method for improving boost pressure control accuracy according to claim 2, characterized in that: The mixing valve opening change rate correction coefficient is determined based on the ratio of the current actual boost pressure to the current target boost pressure and the engine speed, the ratio of the current target boost pressure to the maximum boost pressure, and the ratio of the current target boost pressure to the minimum boost pressure, including: Among them, r2 is the correction coefficient of the mixing valve opening rate change, The ratio of the current actual boost pressure to the current target boost pressure and the correction factor determined by the engine speed n, is the ratio of the current target boost pressure to the maximum boost pressure Determine the correction factor, is the ratio of the current target boost pressure to the minimum boost pressure Determine the correction factor.

6. The method for controlling the opening of a mixing valve for improving the control accuracy of boost pressure according to claim 5, characterized in that: The method for determining each correction coefficient in the calculation formula of the correction coefficient of the mixing valve opening rate is as follows: Ratio of current target boost pressure to maximum boost pressure at different engine speeds n Not greater than 0.5, the ratio of the current target boost pressure to the minimum boost pressure When it is not less than 1.2, the ratio of the current actual boost pressure to the current target boost pressure is adjusted. Get the correction factor Ensure that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from fully open to partially open of the mixing valve is within the preset range does not exceed a first preset time; At the same time, the fluctuation of engine speed n and the ratio of current actual boost pressure to current target boost pressure When the fluctuations do not exceed the respective preset fluctuation ranges, the mixing valve opening change rate correction coefficient r2 is not updated; In determining the correction factor Then, the engine speed n is fixed at different speeds, and the ratio of the current target boost pressure to the maximum boost pressure is tested. Greater than 0.5 and less than 0.95, the ratio of the current target boost pressure to the minimum boost pressure When it is not less than 1.2, adjust the ratio of the current target boost pressure to the maximum boost pressure To determine the correction factor To also ensure that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from fully open to partially open of the mixing valve is within the preset range does not exceed a first preset time; In determining the correction factor and correction factor Then, the engine speed n is fixed at different speeds, and the ratio of the current target boost pressure to the maximum boost pressure is tested. Not greater than 0.5, the ratio of the current target boost pressure to the minimum boost pressure When it is less than 1.2 and not less than 1.02, adjust the ratio of the current target boost pressure to the minimum boost pressure To determine the correction factor This also ensures that the continuous time during which the difference between the target boost pressure and the actual boost pressure in the transition process from full opening to partly full opening of the mixing valve is within the preset range does not exceed the first preset time.

7. The mixing valve opening control method for improving boost pressure control accuracy according to claim 1, characterized in that: The mixing valve opening rate change is corrected based on the mixing valve opening rate change correction coefficient to obtain a final mixing valve opening rate change, including: dpct MGVNew =dpct MGVRaw ×r2×(1+r Adapt ) Among them, dpct MGVNew is the final mixing valve opening change rate, dpct MGVRaw is the mixing valve opening change rate, r2 is the mixing valve opening change rate correction coefficient, r Adapt To learn the update coefficients.

8. The method for controlling the opening of a mixing valve for improving the control accuracy of boost pressure according to claim 7, characterized in that: The activation conditions for learning update coefficients include: The mixing valve is in the transition process from fully open to partially open; The supercharger is in the closed-loop control active state; The absolute value of the engine target intake pressure change rate does not exceed the preset change rate value; The engine mileage corresponding to the learning update coefficient not being updated exceeds the preset mileage value; When the above conditions are met at the same time, the activation condition of the learning update coefficient is met, and the learning update coefficient is updated at this time.

9. The mixing valve opening control method for improving boost pressure control accuracy according to claim 7, characterized in that: The update methods for learning update coefficients include: In the first case, if: The continuous time during which the difference between the target boost pressure and the actual boost pressure exceeds the preset first difference value exceeds the second preset time; The difference between the target EGR rate and the actual EGR rate does not exceed a first preset difference range; The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range; dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference; Then: r Adapt =r Adapt (z)-0.1; where r Adapt (z) is the learning update coefficient obtained from the last learning; In the second case, if: The continuous time during which the difference between the target boost pressure and the actual boost pressure does not exceed the preset first difference value exceeds a second preset time; The difference between the target EGR rate and the actual EGR rate does not exceed a first preset difference range; The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range; dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference; Then: r Adapt =r Adapt (z)+0.08; The third case, if: The continuous time during which the difference between the target boost pressure and the actual boost pressure exceeds the preset first difference value exceeds the second preset time; The difference between the target EGR rate and the actual EGR rate exceeds the first preset difference range for a continuous period exceeding a second preset time; The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range; dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference; Then: r Adapt =r Adapt (z) -0.03; The fourth case, if: The continuous time during which the difference between the target boost pressure and the actual boost pressure does not exceed the preset first difference value exceeds a second preset time; The difference between the target EGR rate and the actual EGR rate exceeds the first preset difference range for a continuous period exceeding a second preset time; The difference between the target mixing valve opening and the actual mixing valve opening does not exceed a second preset difference range; dpct MGVNew -dpct MGVRaw The value of does not exceed a second preset difference; Then: r Adapt =r Adapt (z)+0.02; In other cases, r Adapt =r Adapt (z).

10. The method for controlling the opening of a mixing valve for improving the control accuracy of boost pressure according to claim 9, characterized in that: If the learning update coefficient has been updated once in this driving cycle, the learning update coefficient will not be updated again in this driving cycle.

11. A mixing valve opening control device for improving boost pressure control accuracy, characterized in that: include: An acquisition unit, used for acquiring the current mixing valve opening and the mixing valve opening change rate when the mixing valve is in a transitional operating condition from fully open to not fully open; The intermediate unit is used to determine the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure, and determine the mixing valve opening change rate correction coefficient and the locking time based on the maximum boost pressure, the minimum boost pressure, the current target boost pressure and the current actual boost pressure; wherein the locking time refers to the time for maintaining the current mixing valve opening unchanged; A correction unit, used for correcting the mixing valve opening rate change rate based on the mixing valve opening rate change rate correction coefficient after the locking time ends, to obtain a final mixing valve opening rate change rate; The determination unit is used to determine the mixing valve control opening based on the current mixing valve opening and the final mixing valve opening change rate.

12. A computer device, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the mixing valve opening control method for improving the boost pressure control accuracy as described in any one of claims 1 to 10 are implemented.

13. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the steps of the mixing valve opening control method for improving the boost pressure control accuracy as described in any one of claims 1 to 10 are implemented.

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