Control method and device for entering pressurization closed loop

Abstract

The invention relates to a control method and device for entering a pressurization closed loop. The method comprises the steps that whether pressurization closed loop enabling conditions are met or not is determined; if the pressurization closed-loop enabling condition is met, pressurization closed-loop enabling is started, and target pressurization pressure is determined; and a closed-loop PID control algorithm is set, and a supercharging actuator is controlled, so that the actual supercharging pressure follows the target supercharging pressure. In order to improve the pressure control stability when pressurization enters a closed loop and improve the pressurization responsiveness and the EGR system responsiveness, pressurization closed-loop control is optimized, the closed-loop enabling condition is optimized, the target pressurization pressure and the closed-loop control are optimized, and the pressurization closed-loop control stability and the EGR response precision are improved.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and more particularly to a control method and device for entering a boost closed loop. Background Art

[0002] In order to respond to the engine intake boost and engine torque increase request, the boost system is controlled to achieve more exhaust energy to achieve boost. The boost control determines the engine's power and economy. Boost closed-loop control refers to actively controlling the action of the boost actuator to achieve the following of the actual boost pressure and the target boost pressure. When the boost is not in closed-loop control, the boost actuator opening is not actively controlled. The existing boost control has the problem of poor pressure control stability when the boost enters the closed loop. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a control method and device for entering a boost closed loop, which can identify whether boost pressure closed loop control is required and ensure that the pressure is stable when entering the boost closed loop control.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a control method for entering a boost closed loop, comprising:

[0005] Determine whether the boost closed loop enabling conditions are met;

[0006] If the boost closed-loop enabling condition is met, the boost closed-loop enabling is entered to determine the target boost pressure;

[0007] A closed-loop PID control algorithm is set to control the boost actuator so that the actual boost pressure follows the target boost pressure.

[0008] According to the above scheme, the boost closed loop enabling conditions include:

[0009] The minimum pressure characteristic value is not less than 1;

[0010] The engine speed is greater than the preset value A;

[0011] The pressure relief valve is not open;

[0012] The boost closed loop is enabled only when the above conditions are met at the same time; if the boost closed loop is not enabled, the boost actuator will not work.

[0013] According to the above scheme, the minimum pressure characteristic value b BoostEna Calculated by the following formula:

[0014]

[0015] Where b BoostEnaRaw is the minimum pressure condition flag, k1 is the weighting coefficient, r EGRActis the actual EGR rate, r EGRDesrd is the target EGR rate, n is the engine speed;

[0016] The calibration method is: at different fixed engine speeds, different Under this condition, within the preset time after entering the boost closed loop enablement, the actual boost pressure can reach a value close to the target boost pressure.

[0017] According to the above scheme, the method for determining the preset value A of the engine speed includes:

[0018] If the actual EGR rate r EGRAct 0, that is, the EGR system is not turned on, and the preset value A=B;

[0019] If the actual EGR rate r EGRAct is not 0, and the EGR system is turned on, then A=B×f1(rho,r EGRAct ), where f1(rho,r EGRAct ) is a number not less than 1, rho is the fresh air intake density of the engine; f1(rho,r EGRAct ) is calibrated in each engine with different fresh air intake density rho and different EGR rate r EGRAct Under this condition, the lowest average engine speed n that satisfies the boost closed-loop control accuracy is determined through experiments. Avg , n Avg Dividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f1(rho,r EGRAct );

[0020] If the actual EGR rate r EGRAct When the EGR valve position is not 0 and the EGR valve position is 0, the EGR system is about to be closed. At this time, A=B×f2(rho,r EGRAct ), where f2(rho,r EGRAct ) is a number not greater than 1; f2(rho,r EGRAct ) Its calibration method is used for each different engine fresh air intake density rho and different EGR rate r EGRAct Under this condition, the lowest average engine speed n that satisfies the boost closed-loop control accuracy is determined through experiments. Avg , n Avg Dividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f2(rho,r EGRAct ).

[0021] According to the above scheme, the method for determining the target boost pressure includes:

[0022] Determine the target boost pressure p without dynamic optimization Boost Re qUnDyn :

[0023]

[0024] Among them, p Boost Re qRaw is the currently disclosed target boost pressure, for The obtained first-order low-pass filtered EGR rate characteristic coefficient is updated every other sampling period;

[0025] The target boost pressure p without dynamic optimization Boost Re qUnDyn Further optimization, real-time reading of actual boost pressure, and obtaining dynamically optimized target boost pressure p Boost Re qDyn .

[0026] According to the above scheme, the method for further optimizing the target boost pressure that has not been dynamically optimized includes:

[0027] During this sampling period, if the actual boost pressure p monitored in real time BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling period Boost Re qDyn The absolute value of the difference does not exceed p1, then the target boost pressure p after dynamic optimization Boost Re qDyn In this sampling cycle, it is updated to be equal to the target boost pressure p without dynamic optimization. Boost Re qUnDyn ;

[0028] During this sampling period, if the actual boost pressure p monitored in real time BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling period Boost Re qDyn The absolute value of the difference exceeds p2, and p2 is greater than p1; there are two cases:

[0029] (1) If the actual boost pressure is less than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Increase a certain cumulative amount (-p2+C1);

[0030] (2) If the actual boost pressure is greater than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Increase a certain cumulative amount (p2-C1);

[0031] During this sampling period, if the actual boost pressure p monitored in real time BoostActCompared with the dynamically optimized target boost pressure p in the previous sampling period Boost Re qDyn The absolute value of the difference is between p1 and p2, and the target boost pressure p after dynamic optimization is Boost Re qDyn Equal to the target boost pressure p after dynamic optimization in the previous sampling period Boost Re qDyn Add C2, where C2 is equal to the deviation Δ×k2, Δ is equal to the dynamically optimized target boost pressure p in the previous sampling period Boost Re qDyn The actual boost pressure p BoostAct difference.

[0032] According to the above scheme, the method of setting the closed-loop PID control algorithm includes:

[0033] After the boost closed loop is enabled and the target boost pressure is determined, the P and D items in the PID algorithm are activated, but the I item needs to continue to judge additional conditions before it can be activated, otherwise the closed loop control duty cycle of the I item is 0. The I item needs additional judgment conditions:

[0034] (1) Fresh air mass flow rate entering the cylinder dm CylAir and f(p BoostInlet ) exceeds the preset value X1, the I control is activated;

[0035] (2) Fresh air mass flow rate entering the cylinder dm CylAir and f(p BoostInlet ) does not exceed the preset value X2, then item I control is not activated;

[0036] (3) In other cases, whether item I is activated or not is maintained in the previous state, which is also updated every sampling period;

[0037] Where f(p BoostInlet ) is based on the supercharger compressor inlet pressure p BoostInlet Determine the minimum permissible cylinder fresh air mass flow.

[0038] The present invention also provides a control device for entering a boost closed loop, comprising:

[0039] A boost closed-loop enabling condition judgment module is used to determine whether the boost closed-loop enabling condition is met;

[0040] A target boost pressure acquisition module is used to enter the boost closed loop enablement and determine the target boost pressure if the boost closed loop enablement condition is met;

[0041] The control algorithm setting module is used to set the closed-loop PID control algorithm and control the boost actuator so that the actual boost pressure follows the target boost pressure.

[0042] The present invention also provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the control method for entering a boost closed loop.

[0043] The present invention also provides a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the processor implements the control method for entering a boost closed loop.

[0044] The control method and device for entering a supercharging closed loop according to the present invention have the following beneficial effects:

[0045] In order to improve the pressure control stability when the boost enters the closed loop and improve the boost responsiveness and the EGR system responsiveness, the present invention optimizes the boost closed-loop control. Not only the closed-loop enabling conditions are optimized, but also the target boost pressure and closed-loop control are optimized to improve the boost closed-loop control stability and the EGR response accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0047] Figure 1 is a schematic diagram of the low-pressure EGR system architecture;

[0048] Figure 2 is a flow chart of a control method for entering a boost closed loop according to the present invention;

[0049] Figure 3 It is a logic block diagram of the control method of entering a boost closed loop of the present invention;

[0050] 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-temperature sensor, 12-differential pressure sensor. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0052] The control method for entering a supercharging closed loop of the present invention is aimed at a system with a low-pressure EGR system and an exhaust gas turbocharger system. The system includes an air filter, a mixing valve, a supercharger compressor, a throttle, an engine, a supercharger turbine, a catalyst, a particulate matter trap, an EGR cooler, an EGR valve, an EGR temperature sensor, and an EGR differential pressure sensor.

[0053] The supercharger compressor compresses fresh air for supercharging; the supercharger turbine 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, EGR temperature sensor, EGR valve, EGR differential pressure sensor, and mixing valve; the mixing valve is used to adjust the pressure at the outlet of the EGR valve, increase the pressure difference at both ends of the EGR valve, and increase the EGR rate; the EGR cooler is used to cool the exhaust gas to increase the exhaust gas flow rate and reduce the exhaust gas temperature; the EGR valve has a throttling effect to control the exhaust gas flow entering the cylinder; the EGR temperature sensor is used to detect the exhaust gas temperature entering the EGR valve; the EGR differential pressure sensor is used to detect the pressure at the EGR inlet and outlet. The low-pressure EGR system architecture is as follows: Figure 1 shown.

[0054] Patent CN201910988050.8 "Exhaust Gas Turbine Engine Boost Closed-Loop Adaptive System and Control Method" mentions the boost closed-loop enabling condition judgment, but in order to improve the pressure control stability when the boost enters the closed loop and improve the boost responsiveness and EGR system responsiveness, the boost closed-loop control is optimized.

[0055] like Figure 2-3 As shown, the control method for entering a boost closed loop of the present invention comprises the following steps:

[0056] S1. Determine whether the boost closed-loop enabling conditions are met. The following three conditions must be met at the same time.

[0057] (1) Meet the minimum pressure conditions;

[0058] Patent CN201910988050.8 "Exhaust gas turbine engine boost closed loop adaptive system and control method" mentions the minimum pressure condition flag b BoostMinPreEnaRaw , which means the minimum pressure condition flag bit b BoostMinPreEnaRaw Only when it is 1, it is allowed to enter the boost closed loop enable, otherwise it is not allowed to enter the boost closed loop enable. That is, the minimum pressure condition flag bit b BoostEnaRaw is 1, which is a necessary but not sufficient condition for boost to enter closed loop. BoostEnaRaw The flag bit is adjusted to have only values ​​of 0 and 1. In this embodiment, the minimum pressure condition is optimized, that is, the minimum pressure characteristic value k1 is the weighting coefficient, which is 0.1 in this example, r EGRAct is the actual EGR rate, r EGRDesrd is the target EGR rate, and n is the engine speed. The larger the value, the greater the deviation between the actual EGR rate and the target EGR rate. The larger the value, the faster the boost closed loop is enabled, so as to ensure that when the EGR rate demand increases, the boost outlet pressure is stable when the boost inlet pressure decreases, ensuring the stability of the power. The calibration method is to set different engine speeds at different Under this condition, within the preset time (0.5s in this example) after entering the boost closed loop, the actual boost pressure can be close to the target boost pressure. In this example, the boost pressure closeness means that the difference between the actual boost pressure and the target boost pressure does not exceed ±2kPa. Once b BoostEna If it is not less than 1, it indicates that the minimum pressure condition is met.

[0059] (2) The engine speed n is greater than the preset value A, ensuring that the exhaust gas has sufficient energy to control the boost pressure;

[0060] If the actual EGR rate r EGRAct If it is 0, that is, the EGR system is not turned on, the preset value B is maintained the same as that in patent CN201910988050.8 "Exhaust gas turbine engine boost closed loop adaptive system and control method", that is, A=B at this time;

[0061] If the actual EGR rate r EGRAct is not 0, and the EGR valve position opening (the opening is 0%, which means that the gas on both sides of the EGR valve is blocked and cannot flow; the larger the opening, the larger the effective flow area on both sides of the EGR valve) is greater than the preset value (0.6% in this example), that is, the EGR system is turned on, then A=B×f1(rho,r EGRAct ), where f1(rho,r EGRAct ) is a number not less than 1. Its purpose is to fix the fresh air intake density rho entering the cylinder, but when the actual EGR rate is different, part of the exhaust gas energy is used for the EGR system, and the supercharging system capacity is insufficient. It is necessary to enter the supercharging closed loop when the engine speed is higher. The actual EGR rate r EGRAct The larger the value, the greater the f1(rho,r EGRAct The greater the fresh air intake density rho entering the cylinder, the greater the exhaust gas energy, the stronger the supercharging ability, and the greater the fresh air intake density rho entering the cylinder, f1(rho,r EGRAct ) is smaller. EGRAct ) The calibration method is to conduct a large number of experiments on each engine with different fresh air intake density rho and different EGR rate r EGRAct Under this condition, a large number of tests were conducted to determine the lowest average engine speed n that satisfies the boost closed-loop control accuracy (the difference between the target boost pressure and the actual boost pressure is within ±2kPa, indicating that the boost closed-loop control accuracy is met). Avg , n AvgDividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f1(rho,r EGRAct ).

[0062] If the actual EGR rate r EGRAct When it is not 0 and the EGR valve position opening is 0, the EGR system is about to be closed. Due to the delay of exhaust gas energy, the exhaust gas energy is relatively large. At this time, A=B×f2(rho,r EGRAct ), where f2(rho,r EGRAct ) is a number not greater than 1, and the engine speed is small and has enough energy to ensure the supercharging capacity. The actual EGR rate r EGRAct The larger the value, the greater the f2(rho,r EGRAct The greater the fresh air intake density rho entering the cylinder, the greater the exhaust gas energy, the stronger the supercharging ability, and the greater the fresh air intake density rho entering the cylinder, f2(rho,r EGRAct ) is smaller. f2(rho,r EGRAct ) The calibration method is to conduct a large number of experiments on each engine with different fresh air intake density rho and different EGR rate r EGRAct Under this condition, a large number of tests were conducted to determine the lowest average engine speed n that satisfies the boost closed-loop control accuracy (the difference between the target boost pressure and the actual boost pressure is within ±2kPa, indicating that the boost closed-loop control accuracy is met). Avg , n Avg Dividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f2(rho,r EGRAct ). Finally, A in this case is limited to not less than a preset value D, which is 700 rpm in this example.

[0063] (3) The pressure relief valve is not opened;

[0064] The boost closed loop is enabled only when the above conditions are met. If the boost closed loop is not enabled, the boost actuator will not work.

[0065] S2, after the boost closed loop is enabled, the boost actuator is controlled so that the actual boost pressure follows the target boost pressure. The purpose of this step is to determine the target boost pressure. In order to further ensure the stability of pressure control after the boost closed loop is enabled and improve the boost pressure control stability, the target boost pressure is dynamically optimized. Step S2 specifically includes the following steps:

[0066] S201, optimizing the target boost pressure based on the EGR rate to ensure that after the EGR function is activated, due to the hysteresis of the actual EGR rate response, the target boost pressure overshoot caused by the dynamic change of the EGR rate occurs, and the target boost pressure is optimized. First, the target boost pressure p that is not dynamically optimized is determined. Boost Re qUnDyn .

[0067]

[0068] Among them, p Boost Re qRaw is the currently disclosed target boost pressure, for The obtained filtered EGR rate characteristic coefficient after the first-order low-pass filtering is updated every other sampling period, and the sampling period in this example is 10ms.

[0069] is the characteristic coefficient of the filtered EGR rate after the first-order low-pass filter in the Nth sampling period, is the characteristic coefficient of the filtered EGR rate after the first-order low-pass filter in the N-1th sampling period, where N = 1, 2, 3, ..., in particular, The occurrence time is when the engine just starts, and its corresponding value is 1, Δt is the sampling cycle time, that is, 10ms, and T is the filtering time.

[0070] T=f(dm CylAir ), dm CylAir is the mass flow of fresh air entering the cylinder. The method for obtaining T is obtained through calibration. The calibration method is that the overshoot of the target boost pressure does not exceed the preset value. In this example, ±3kPa is taken. That is, when the engine speed is fixed and the fresh air intake density entering the cylinder is fixed, the target EGR rate is adjusted, and the overshoot of the target boost pressure finally obtained under the stable working condition when it changes does not exceed ±3kPa. Based on this, the time T is obtained after reading the corresponding mass flow of fresh air entering the cylinder.

[0071] S202: Target boost pressure p that is not dynamically optimized Boost Re qUnDyn Further optimization, real-time reading of actual boost pressure, and obtaining dynamically optimized target boost pressure p Boost Re qDyn . Specifically, it can be divided into the following three situations.

[0072] (1) During this sampling period, if the actual boost pressure p monitored in real time is BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling period Boost Re qDyn The absolute value of the difference does not exceed p1 (p1>0, 3kPa in this example), then the target boost pressure p after dynamic optimization is Boost Re qDynIn this sampling cycle, it is updated to be equal to the target boost pressure p without dynamic optimization. Boost Re qUnDyn .

[0073] (2) If the actual boost pressure p monitored in real time is not satisfied in step 2.1, BoostAct Compared with the target boost pressure p without dynamic optimization Boost Re qUnDyn The absolute value of the difference exceeds a certain value p2 (the absolute value of p2 is greater than p1, which is 10 kPa in this example), 1) If the actual boost pressure is less than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Add a certain cumulative amount (-p2+C1), C1 in this example is 3kPa, 2) If the actual boost pressure is greater than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Add a certain cumulative amount (p2-C1), C1 in this example is 3kPa. Get the new dynamically optimized target boost pressure p Boost Re qDyn .

[0074] (3) In other cases, the target boost pressure p after dynamic optimization Boost Re qDyn Equal to the target boost pressure p after dynamic optimization in the previous sampling period Boost Re qDyn Add C2, where C2 is equal to the deviation Δ×k2, the coefficient of variation k2 in this example takes the default value of 0.35, and Δ is equal to the target boost pressure p after dynamic optimization in the previous sampling period Boost Re qDyn The actual boost pressure p BoostAct difference.

[0075] S3. After the boost closed loop is enabled and the target boost pressure is determined, the P and D items in the PID algorithm are activated, but the I item needs to continue to judge additional conditions before it can be activated, otherwise the closed loop control duty cycle of the I item is 0, and the P and D item control methods are the same as the conventional PD control method. The I item needs additional judgment conditions:

[0076] (1) Fresh air mass flow rate entering the cylinder dm CylAir and f(p BoostInlet ) exceeds the preset value X1 (1g / s in this example), the I control is activated;

[0077] (2) Fresh air mass flow rate entering the cylinder dm CylAir and f(p BoostInlet ) does not exceed the preset value X2 (1.5g / s in this example), the I control is not activated;

[0078] (3) In other cases, whether the I control is activated or not is maintained in the previous state, and it is also updated every sampling period. The default state is that the I control is not activated;

[0079] Where f(p BoostInlet ) is based on the supercharger compressor inlet pressure p BoostInlet The minimum allowable cylinder fresh air mass flow rate is determined as , as shown in Table 1. When the mass flow rate is lower than this, the integral term I is easily saturated.

[0080] Table 1

[0081]

[0082] The purpose of setting the above additional activation condition of item I is that if the cylinder flow is too small, the exhaust energy will be too small. If item I is activated, closed-loop control integral saturation will easily occur when the cylinder flow is too small. This is why the condition is set to improve the integral saturation of item I.

[0083] After the I term is activated, the I term control method is also the same as the I term algorithm in the conventional PID algorithm.

[0084] Embodiment 2

[0085] The present invention also provides a control device for entering a boost closed loop, comprising:

[0086] A boost closed-loop enabling condition judgment module is used to determine whether the boost closed-loop enabling condition is met;

[0087] A target boost pressure acquisition module is used to enter the boost closed loop enablement and determine the target boost pressure if the boost closed loop enablement condition is met;

[0088] The control algorithm setting module is used to set the closed-loop PID control algorithm and control the boost actuator so that the actual boost pressure follows the target boost pressure.

[0089] Embodiment 3

[0090] The invention also provides an automobile, comprising a control device for entering a supercharging closed loop.

[0091] Embodiment 4

[0092] The present invention also provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the control method for entering a boost closed loop.

[0093] Embodiment 5

[0094] The present invention also provides a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the processor implements the control method for entering a boost closed loop.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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 A step that specifies a function in one or more boxes.

[0099] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A control method for entering a boost closed loop, characterized in that: include: Determine whether the boost closed loop enabling conditions are met; If the boost closed-loop enabling condition is met, the boost closed-loop enabling is entered to determine the target boost pressure; A closed-loop PID control algorithm is set to control the boost actuator so that the actual boost pressure follows the target boost pressure.

2. The control method for entering a supercharging closed loop according to claim 1, characterized in that: The boost closed loop enabling conditions include: The minimum pressure characteristic value is not less than 1; The engine speed is greater than the preset value A; The pressure relief valve is not open; The boost closed loop is enabled only when the above conditions are met at the same time; if the boost closed loop is not enabled, the boost actuator will not work.

3. The control method for entering a supercharging closed loop according to claim 2, characterized in that: Minimum pressure characteristic value b BoostEna Calculated by the following formula: Where b BoostEnaRaw is the minimum pressure condition flag, k1 is the weighting coefficient, r EGRAct is the actual EGR rate, r EGRDesrd is the target EGR rate, n is the engine speed; The calibration method is: at different fixed engine speeds, different Under this condition, within the preset time after entering the boost closed loop enablement, the actual boost pressure can reach a value close to the target boost pressure.

4. The control method for entering a supercharging closed loop according to claim 3, characterized in that: The method for determining the preset value A of the engine speed includes: If the actual EGR rate r EGRAct 0, that is, the EGR system is not turned on, and the preset value A=B; If the actual EGR rate r EGRAct is not 0, and the EGR system is turned on, then A=B×f1(rho,r EGRAct ), where f1(rho,r EGRAct ) is a number not less than 1, rho is the fresh air intake density of the engine; f1(rho,r EGRAct ) is calibrated in each engine with different fresh air intake density rho and different EGR rate r EGRAct Under this condition, the lowest average engine speed n that satisfies the boost closed-loop control accuracy is determined through experiments. Avg , n Avg Dividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f1(rho,r EGRAct ); If the actual EGR rate r EGRAct When the EGR valve position is not 0 and the EGR valve position is 0, the EGR system is about to be closed. At this time, A=B×f2(rho,r EGRA ct), where f2(rho,r EGRA ct) is a number not greater than 1; f2(rho,r EGRAct ) Its calibration method is used for each different engine fresh air intake density rho and different EGR rate r EGRAct Under this condition, the lowest average engine speed n that satisfies the boost closed-loop control accuracy is determined through experiments. Avg , n Avg Dividing by B gives the fresh air intake density rho for each engine and each different EGR rate r EGRAct f2(rho,r EGRAct ).

5. The control method for entering a supercharging closed loop according to claim 3, characterized in that: Methods for determining target boost pressure include: Determine the target boost pressure p without dynamic optimization Boost Re qUnDyn : Among them, p BoostReqRaw is the currently disclosed target boost pressure, for The obtained first-order low-pass filtered EGR rate characteristic coefficient is updated every other sampling period; The target boost pressure p without dynamic optimization BoostReqUnDyn Further optimization, real-time reading of actual boost pressure, and obtaining dynamically optimized target boost pressure p BoostReqDyn .

6. The control method for entering a supercharging closed loop according to claim 5, characterized in that: Methods for further optimizing the target boost pressure that has not been dynamically optimized include: During this sampling period, if the actual boost pressure p monitored in real time BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling cycle Boost Re qDyn If the absolute value of the difference does not exceed p1, the target boost pressure p after dynamic optimization BoostReqDyn In this sampling cycle, it is updated to be equal to the target boost pressure p without dynamic optimization. BoostReqUnDyn ; During this sampling period, if the actual boost pressure p monitored in real time BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling cycle Boost Re qDyn The absolute value of the difference exceeds p2, and p2 is greater than p1; there are two cases: (1) If the actual boost pressure is less than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Increase a certain cumulative amount (-p2+C1); (2) If the actual boost pressure is greater than the target boost pressure p without dynamic optimization Boost Re qUnDyn , the target boost pressure p that is not dynamically optimized is Boost Re qUnDyn Increase a certain cumulative amount (p2-C1); During this sampling period, if the actual boost pressure p monitored in real time BoostAct Compared with the dynamically optimized target boost pressure p in the previous sampling cycle Boost Re qDyn The absolute value of the difference is between p1 and p2, and the target boost pressure p after dynamic optimization is Boost Re qDyn Equal to the target boost pressure p after dynamic optimization in the previous sampling period BoostReqDyn Add C2, where C2 is equal to the deviation Δ×k2, Δ is equal to the dynamically optimized target boost pressure p in the previous sampling period BoostReqDyn The actual boost pressure p BoostAct difference.

7. The control method for entering a supercharging closed loop according to claim 1, characterized in that: Methods for setting a closed-loop PID control algorithm include: After the boost closed loop is enabled and the target boost pressure is determined, the P and D items in the PID algorithm are activated, but the I item needs to continue to judge additional conditions before it can be activated, otherwise the closed loop control duty cycle of the I item is 0. The I item needs additional judgment conditions: (1) Fresh air mass flow rate entering the cylinder dm CylAir and f(p B oost I When the difference between nlet) exceeds the preset value X1, the I control is activated; (2) Fresh air mass flow rate entering the cylinder dm CylAir and f(p B oost I When the difference between nlet) does not exceed the preset value X2, item I control is not activated; (3) In other cases, whether item I is activated or not is maintained in the previous state, which is also updated every sampling period; Where f(p BoostInlet ) is based on the supercharger compressor inlet pressure p BoostInlet Determine the minimum permissible cylinder fresh air mass flow.

8. A control device for entering a boost closed loop, characterized in that: include: A boost closed-loop enabling condition judgment module is used to determine whether the boost closed-loop enabling condition is met; A target boost pressure acquisition module is used to enter the boost closed loop enablement and determine the target boost pressure if the boost closed loop enablement condition is met; The control algorithm setting module is used to set the closed-loop PID control algorithm and control the boost actuator so that the actual boost pressure follows the target boost pressure.

9. An electronic device, comprising: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; characterized in that a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the control method for entering a boost closed loop as described in any one of claims 1 to 7.

10. A computer-readable storage medium having executable instructions stored thereon, characterized in that: When the instruction is executed by the processor, the processor implements the control method for entering a supercharging closed loop as described in any one of claims 1 to 7.

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