Engine control method and device and vehicle

Abstract

The invention discloses an engine control method and device and a vehicle, and relates to the technical field of vehicle control. The method comprises the steps that in response to release of an accelerator pedal of a vehicle, whether an engine is in a fuel cut-off forbidding working condition or not is judged; if yes, the required opening degree of a throttle valve is determined through the required power of the engine, and the surge opening degree of the throttle valve is calculated according to the current air inlet flow of the throttle valve and the current supercharging pressure of the engine; when the throttle valve demand opening degree is smaller than the throttle valve surge opening degree, the throttle valve is controlled to be closed at a first preset speed, and when the throttle valve is closed to the throttle valve surge opening degree, the current intake flow of the throttle valve and the current supercharging pressure of the engine are updated to update the throttle valve surge opening degree until the throttle valve surge opening degree is smaller than the throttle valve demand opening degree; and the throttle valve is controlled to be closed to the throttle valve required opening degree at the first preset speed. By means of the method, the pressure relief requirement of the engine after a pressure relief valve is omitted can be met, and meanwhile the surge problem of the engine is solved.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to an engine control method, device and vehicle. Background Technology

[0002] Currently, most engines used in vehicles are turbocharged engines. (See also...) Figure 1 The turbocharged engine shown consists of two parts: a turbocharger and an engine. When the user drives the vehicle, pressing the accelerator pedal compresses the air entering through the air filter into high-pressure gas, which is then sent into the intake manifold. After being cooled by the intercooler, the gas is sent into the engine through the throttle valve to participate in combustion and generate power. At the same time, the exhaust gas produced by the engine combustion acts on the turbocharger, causing the turbocharger turbine to rotate continuously, further compressing the air entering through the air filter. This cycle continues, thus meeting the power requirements of the vehicle while driving.

[0003] When a driver wants the vehicle to slow down, they typically release the accelerator pedal and / or press the brake pedal. In response, the engine control system closes the throttle, reducing or eliminating the intake of air into the engine, thus decreasing power output and slowing the vehicle. However, after the throttle closes, the turbocharger's turbine continues to compress air, causing a rapid increase in pressure within the intake manifold between the turbocharger and the throttle, creating a pressure relief demand. Currently, the mainstream engine pressure relief method uses a blow-off valve. When the driver releases the accelerator and / or brakes, creating a pressure relief demand, the blow-off valve opens, releasing the high-pressure air from the intake manifold. However, this method produces a loud exhaust noise, which is noticeable to the driver and negatively impacts the driving experience.

[0004] Therefore, the pressure relief method of eliminating the pressure relief valve has been proposed. Currently, intelligent pressure relief is achieved by deploying control strategies within the Engine Control Unit (ECU). For example, when the user releases the accelerator pedal, the throttle valve is controlled to close slowly and / or with a delayed closure, allowing some of the high-pressure gas in the intake manifold to be sent into the engine and discharged through the engine's exhaust system, thus achieving pressure relief. However, in this method, as the throttle valve slowly closes, the airflow that can pass through the throttle valve continuously decreases, which may still lead to an increase in pressure within the intake manifold, making turbocharged engines still susceptible to surge. Summary of the Invention

[0005] In view of the above problems, this application provides an engine control method, device, and vehicle that overcomes or at least partially solves the above problems, and the technical solution is as follows: In a first aspect, this application proposes an engine control method applied to a vehicle. The method includes: in response to the release of the accelerator pedal, determining whether the engine is in a no-fuel-cut-off condition; if so, determining the required throttle opening based on the engine's required power, and calculating the throttle surge opening based on the current throttle intake flow and the current engine boost pressure; wherein the throttle surge opening is the minimum opening of the throttle corresponding to the engine not surging under the current engine boost pressure; when the required throttle opening is less than the throttle surge opening, controlling the throttle to close at a first preset speed, and updating the current throttle intake flow and the current engine boost pressure to update the throttle surge opening when the throttle closes to the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and controlling the throttle to close to the required throttle opening at the first preset speed.

[0006] The engine control scheme provided in this application first determines the engine's operating condition when the user releases the accelerator pedal. If the engine is in a no-fuel-cut-off condition, meaning the vehicle still has a power demand (e.g., the engine needs to output power after the user releases the accelerator pedal due to the air conditioning system being on), the required throttle opening is calculated. This required opening is the throttle opening corresponding to the intake airflow needed for the engine to continue working to meet the vehicle's current power demand. Simultaneously, the throttle surge opening is calculated based on the current throttle intake airflow and the current engine boost pressure. Based on the relationship between the required throttle opening and the surge opening, the throttle is controlled to close in stages: when the required throttle opening is less than the surge opening, it first closes to the surge opening at a first preset speed, then updates the surge opening in real-time by updating the throttle intake airflow and engine boost pressure until the required throttle opening is greater than the surge opening, at which point it can be safely closed to the required throttle opening. During this process, when the user releases the accelerator pedal, the vehicle's power demand is lower than before the user released the pedal due to the vehicle's deceleration. Therefore, the throttle valve will inevitably move towards a smaller opening, causing an increase in intake manifold pressure, leading to engine pressure relief and a risk of surge. However, by precisely controlling or gradually controlling the throttle valve opening, the throttle valve can be slowly closed to the required opening, allowing the intake manifold pressure to decrease smoothly. This achieves stable engine pressure relief and avoids the surge problems caused by a sudden increase in intake manifold pressure and backflow of airflow due to the throttle valve closing too quickly or directly to a relatively small required opening. Simultaneously, it ensures the engine's power demand under conditions where fuel cut-off is not allowed, maintaining vehicle operational stability and achieving a balance between surge suppression and operational adaptability in scenarios without a pressure relief valve.

[0007] In one possible implementation of this application, calculating the throttle surge opening based on the current throttle intake flow rate and the current engine boost pressure includes: determining the engine surge pressure corresponding to the current throttle intake flow rate based on the engine surge line; calculating the pressure difference between the engine surge pressure and the current engine boost pressure, and calculating the intake flow rate corresponding to the pressure difference; and determining the throttle surge opening through the flow difference between the current engine intake flow rate and the intake flow rate corresponding to the pressure difference.

[0008] This implementation presents a strategy for updating the throttle surge opening. The engine surge line represents the relationship between engine intake airflow and the maximum pressure when surge does not occur. For example, the surge line determines the surge pressure corresponding to a certain intake airflow. Surge occurs when the boost pressure in the engine intake manifold exceeds this surge pressure. Therefore, the surge pressure corresponding to the current intake airflow is determined using the engine surge line. The corresponding intake airflow is then calculated using the pressure difference between the surge pressure and the current boost pressure. This intake airflow represents the adjustable gas flow remaining in the intake manifold when the throttle opening is adjusted, assuming the engine does not surge. It also represents the intake airflow that can be further reduced by the throttle. Therefore, this intake airflow corresponds to the change in throttle opening. The throttle surge opening is then calculated using the change in throttle opening and the current opening. In other words, the throttle surge opening is determined using the flow difference between the current intake airflow and the intake airflow corresponding to the pressure difference. As the throttle gradually closes from its current opening to the surge opening, the throttle opening continuously decreases, resulting in a decrease in the intake airflow through the throttle and a decrease in the exhaust gas produced by engine combustion. This reduces the speed of the turbocharger turbine driven by the exhaust gas, leading to a decrease in the pressure of the compressed gas after turbocharging, thus achieving a smooth depressurization of the engine. As the intake airflow and boost pressure decrease, the calculated throttle surge opening also continuously decreases, thereby updating the throttle surge opening. This is a prerequisite for dynamically closing the throttle to a relatively small required opening. Furthermore, the calculation of the throttle surge opening is directly related to the engine's core parameters and surge curve, ensuring the accuracy of the calculated surge opening as the minimum opening to prevent surge. Without a pressure relief valve, a precise surge opening provides a reliable threshold for throttle control, avoiding the risk of surge or excessive throttling caused by calculation errors, further preventing surge from occurring.

[0009] In one possible implementation of this application, controlling the throttle valve to close at a first preset speed includes: determining the first preset speed for throttle valve closing based on the opening difference between the current throttle valve opening and the throttle valve surge opening.

[0010] In this implementation, when the throttle valve closes from its current opening to the surging opening, a first preset closing speed is determined based on the opening difference. When the opening difference is relatively large, the closing speed of the throttle valve can be controlled to be higher in order to respond promptly. When the opening difference is relatively small, it means that the current opening of the throttle valve is close to the surging opening. At this time, a relatively low speed can be selected to close the throttle valve. On the one hand, this avoids the throttle valve from closing too quickly and causing surging. On the other hand, the relatively small closing speed allows the throttle valve to close more smoothly, avoiding large fluctuations in the pressure in the intake manifold caused by the throttle valve closing too quickly, which could lead to the risk of surging.

[0011] In one possible implementation of this application, after obtaining the throttle demand opening and the throttle surge opening, the method further includes: determining that the throttle demand opening is greater than the throttle surge opening; and controlling the throttle to adjust to the throttle demand opening.

[0012] In this implementation, when the engine is not allowed to cut off fuel, if the required throttle opening corresponding to the engine's required power is greater than the throttle surge opening, the throttle opening can be directly adjusted to the required opening without surging because the required opening is already within the safe range where surging will not occur.

[0013] In one possible implementation of this application, the current boost pressure of the engine is acquired by a preset pressure sensor, which is located inside the engine intake manifold and between the intercooler and the throttle valve.

[0014] In this implementation, a pressure sensor is installed between the intercooler and the throttle valve in the engine intake manifold to collect the boost pressure in the intake manifold in real time. On the one hand, the pressure value at this location can directly reflect the actual intake pressure at the front of the throttle valve. Compared with other locations such as the turbocharger outlet, it can more accurately reflect the changes in the pressure state in the intake manifold caused by the throttle valve closing. On the other hand, the accurate boost pressure is the basis for calculating the throttle surge opening. By setting up a pressure sensor to collect accurate boost pressure in real time, the accuracy of the calculated throttle surge opening can be ensured, avoiding the misjudgment of surge caused by pressure acquisition deviation, and ensuring the effective solution of the surge problem.

[0015] In one possible implementation of this application, in response to the release of the accelerator pedal, determining whether the engine is in a prohibited fuel cut-off condition further includes: determining that the engine is in a permitted fuel cut-off condition; determining the current intake airflow of the throttle and the current boost pressure of the engine; determining the engine surge pressure corresponding to the current intake airflow of the throttle based on the engine surge line; and controlling the opening and closing of the throttle using the current boost pressure and the engine surge pressure.

[0016] In this implementation, when the user releases the accelerator pedal and the engine is in a permissible fuel cut-off condition, the engine surge pressure is determined by the current intake airflow through the throttle and the surge line. Then, the throttle opening and closing are controlled based on the relationship between the current boost pressure and the engine surge pressure. Under permissible fuel cut-off conditions, the vehicle has no power demand, and the engine no longer needs to maintain fuel injection and therefore stops burning to output power. At this time, by comparing the current boost pressure with the surge pressure, it is possible to directly determine whether the engine has a surge risk, thus effectively suppressing the surge risk.

[0017] In one possible implementation of this application, controlling the opening and closing of the throttle valve based on the current engine boost pressure and the engine surge pressure includes: if the current engine boost pressure is greater than the engine surge pressure, then controlling the throttle valve to adjust to its maximum opening; if the current engine boost pressure is less than the engine surge pressure, then controlling the throttle valve to remain closed or controlling the throttle valve to close at a second preset speed.

[0018] In this implementation, when the current boost pressure of the engine is greater than the surge pressure, it indicates a risk of surge. At this time, the throttle is adjusted to its maximum opening, allowing the high-pressure gas in the intake manifold to enter the engine's exhaust passage through the throttle and be discharged, thus depressurizing the engine while preventing backflow and surge. Conversely, when the current boost pressure of the engine is less than the surge pressure, it means that the current boost pressure will not cause surge. In this case, the throttle can be kept closed or closed at a second preset speed.

[0019] In one possible implementation of this application, when the throttle demand opening is less than the throttle surge opening, the method further includes: acquiring road condition information ahead of the vehicle, and determining the future power demand within a preset time period based on the road condition information ahead of the vehicle; determining the future throttle demand opening corresponding to the future power demand; and if the future throttle demand opening is greater than the throttle surge opening, controlling the throttle to adjust to the future throttle demand opening.

[0020] In this implementation, when the engine is prohibited from cutting off fuel and the throttle opening demand is less than the throttle surge opening, the system can also predict the vehicle's power demand for a preset period and the corresponding future throttle opening demand based on the road conditions ahead. If the future demand opening is greater than the surge opening, the system can directly adjust to the future demand opening. For example, when a user drives the vehicle over a speed bump, releases the accelerator pedal, and then suddenly brakes, the throttle opening demand rapidly decreases to below the surge opening. The vehicle's driver assistance function determines that the user is driving over the speed bump and that there is a high probability that the user will press the accelerator pedal after passing the speed bump, causing the future throttle opening demand to be greater than the surge opening. In this case, the system can directly control the throttle to adjust to the future demand opening. This avoids frequent throttle adjustments in a short period due to driving scenarios such as driving over speed bumps or turning, while also meeting the vehicle's future power demand in advance, improving driving smoothness and stability.

[0021] It's important to note that while this implementation adjusts the throttle opening in advance to meet future power demands, the user's release of the accelerator still triggers combustion control in the engine. This includes adjusting parameters such as fuel injection and ignition timing to match the vehicle's current power requirements, thus reducing engine output and accommodating the user's need to slow down the vehicle. In other words, even if the throttle opening is adjusted in advance to meet future demands, resulting in a higher intake airflow than the current demand, the increased intake airflow won't all participate in combustion due to combustion control; it will be expelled through the exhaust system. Alternatively, this implementation might determine the future power demand within a preset timeframe, such as a short period (e.g., tens of seconds or a minute). In this case, combustion control can still match fuel injection, ignition timing, and other combustion parameters with the intake airflow, maintaining the air-fuel mixture ratio within a reasonable range. Although this would result in the engine output power being higher than the current power requirement of the vehicle, the excess power can be consumed by charging new energy vehicles or by providing braking force to the wheels of the vehicle while meeting the power requirement. This can avoid the risk of surge and maintain the combustion stability of the engine, achieving smooth depressurization of the engine and stable control of the vehicle.

[0022] Secondly, this application proposes a control device, the control device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform: in response to the release of the accelerator pedal of a vehicle, determining whether the engine is in a no-fuel-cut-off condition; if so, determining the required throttle opening based on the engine's required power, and based on the current intake airflow of the throttle and the current boost pressure of the engine. The throttle surge opening is calculated; wherein, the throttle surge opening is the minimum opening of the throttle corresponding to the engine without surge under the current boost pressure of the engine; when the required throttle opening is less than the required throttle surge opening, the throttle is controlled to close at a first preset speed, and when the throttle closes to the required throttle surge opening, the current intake air flow of the throttle and the current boost pressure of the engine are updated to update the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and the throttle is controlled to close to the required throttle opening at the first preset speed.

[0023] Thirdly, this application also provides a vehicle, including an engine and the control device proposed in the second aspect, enabling the vehicle to: determine whether the engine is in a no-fuel-cut-off condition in response to the release of the accelerator pedal; if so, determine the required throttle opening based on the engine's required power, and calculate the throttle surge opening based on the current throttle intake flow and the current engine boost pressure; wherein the throttle surge opening is the minimum opening of the throttle corresponding to the engine not surging under the current engine boost pressure; when the required throttle opening is less than the throttle surge opening, control the throttle to close at a first preset speed, and when the throttle closes to the throttle surge opening, update the current throttle intake flow and the current engine boost pressure to update the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and control the throttle to close to the required throttle opening at the first preset speed.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This illustration shows a schematic diagram of a turbocharged engine structure provided in this application / an embodiment of this application; Figure 2 A flowchart of an engine control method provided in this application / an embodiment of this application is shown; Figure 3 This paper shows an overall flowchart of an engine control method provided in this application / an embodiment of this application; Figure 4 A schematic diagram of the structure of an engine control device provided in this application / an embodiment of this application is shown. Detailed Implementation

[0026] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0027] The engine control method proposed in this application is preferably applicable to turbocharged engines. For example... Figure 1 As shown, a turbocharged engine consists of two parts: a turbocharger and an engine. When the user is driving the vehicle, the gas entering through the air filter is compressed by the turbocharger to form high-pressure gas, which enters the intake manifold, is cooled by the intercooler, and then enters the engine through the throttle valve to participate in combustion, enabling the engine to output power. The exhaust gas produced by the engine combustion drives the turbocharger turbine to rotate, causing the turbocharger to continue compressing gas, and so on, to meet the power demand of the vehicle during driving.

[0028] When a user releases the accelerator pedal or presses the brake after releasing the accelerator pedal, the engine control system closes the throttle valve in response to this action. After the throttle valve closes, the high-pressure gas in the intake manifold cannot enter the engine to participate in combustion, or only a very small amount of gas enters the engine through the throttle valve. At the same time, the turbocharger turbine, due to inertia, continues to rotate, continuing to input compressed high-pressure gas into the intake manifold. This causes a sudden increase in pressure within the intake manifold between the turbocharger outlet and the throttle valve. Therefore, when the user releases the accelerator pedal, the intake manifold needs to be depressurized, meaning the engine has a pressure relief requirement. If the pressure in the intake manifold is not released in time after the user releases the accelerator pedal, or if only a small portion of the pressure is released, the high-pressure gas will flow backward and impact the turbine blades, posing a risk of engine surge.

[0029] Currently, the mainstream pressure relief method uses a pressure relief valve. When the user releases the accelerator pedal and the engine needs to release pressure, the pressure relief valve opens, expelling the high-pressure gas in the intake manifold. However, this method produces a significant venting noise, which is perceptible to the user and affects their driving experience. Meanwhile, to accommodate the need for simplified vehicle configurations, a pressure relief method eliminating the pressure relief valve and pipeline has been proposed, achieving intelligent pressure relief through the control strategy of the Engine Control Unit (ECU). For example, when the user releases the accelerator pedal, the throttle valve can be slowly closed or closed after a delay, allowing the engine to continue outputting power. The engine continues to work, consuming the gas in the intake manifold, thus achieving pressure relief. However, during the slow closing of the throttle valve, the intake airflow entering the engine through the throttle valve continuously decreases, while the amount of gas remaining in the intake manifold continuously increases. This can still lead to an increase in pressure within the intake manifold, making the engine still susceptible to surge. On the other hand, the pressure relief scheme that closes the throttle valve after a certain delay may have several drawbacks. If the delay is short, the turbocharger turbine speed will not have enough time to drop, and it will continue to deliver a large amount of high-pressure gas to the intake manifold, which will also increase the pressure in the intake manifold and pose a risk of surge. However, if the delay is long, the engine will need to keep burning gas to do work, resulting in energy waste.

[0030] In summary, the technical problem to be solved in this application is to address the risk of surge in turbocharged engines or turbochargers when the accelerator pedal is released after the pressure relief valve is removed.

[0031] Based on this, this application provides an engine control method, such as... Figure 2 As shown. Figure 2 A flowchart of an engine control method provided for this application / an embodiment of this application specifically includes the following execution steps: Step 201: In response to the release of the accelerator pedal, determine whether the engine is in a condition where fuel cut-off is prohibited.

[0032] The engine control method proposed in this application can be executed by the engine control system or the vehicle control system, but preferably by the ECU. In one example, the engine control method of this application can be formed into a control strategy and deployed or written into the ECU for execution by the ECU.

[0033] When a user wants the vehicle to slow down, they will release the accelerator pedal or, after releasing the accelerator, press the brake pedal. At this time, the ECU will determine whether the engine is in a prohibited fuel cut-off condition or a permitted fuel cut-off condition. A prohibited fuel cut-off condition means that after the user releases the accelerator pedal, the vehicle still requires power, and the engine needs to continue burning fuel to output power. A permitted fuel cut-off condition means that after the user releases the accelerator pedal, the vehicle has no power demand or only a small power demand. In this case, the engine can stop burning fuel to output power, and fuel injection to the engine can be stopped. For example, if the user turns on the air conditioning system while driving, requiring the air conditioning system to output cold or warm air into the cabin, and after the user releases the accelerator pedal, the air conditioning system is still running, requiring the engine to continue burning fuel to maintain the air conditioning system's operation. In this case, the ECU can determine that the engine is in a prohibited fuel cut-off condition.

[0034] In one example, the engine must not cut off fuel supply in a condition where the engine needs to continue outputting power to meet vehicle performance, emission, or functional requirements. For example, the engine running time does not meet the minimum running time requirement, the engine speed does not meet the fuel cut-off requirement, the engine exhaust temperature is too high and fuel cut-off is prohibited, or the Gasoline Particulate Filter (GPF) prohibits fuel cut-off.

[0035] Step 202: If yes, then determine the required throttle opening based on the engine's required power, and calculate the throttle surge opening based on the current intake airflow and the current boost pressure of the engine.

[0036] Step 203: When the required throttle opening is less than the required throttle surge opening, control the throttle to close at a first preset speed. When the throttle closes to the required throttle surge opening, update the current intake air flow and the current boost pressure of the engine to update the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and control the throttle to close to the required throttle opening at the first preset speed.

[0037] The ECU determines whether the engine is in a no-fuel-cut-off condition, and there are two possible outcomes: either the engine is in a no-fuel-cut-off condition, or the engine is in a fuel-cut-off-allowed condition. For details on the different conditions, please refer to [link to relevant documentation]. Figure 3 There are different anti-surge logics, and the specific solutions are described below: In situations where engine fuel cut-off is prohibited, the vehicle still has a power demand. For example, if the air conditioning system is on, the engine still needs to output power after the user releases the accelerator pedal. In this case, the power demand issued by the Power Domain Control Unit (PDCU) is used to calculate the required throttle opening. The required opening is the throttle opening corresponding to the intake air flow required by the engine to continue working to meet the vehicle's current power demand. Simultaneously, the current intake airflow of the throttle body and the current boost pressure of the engine are collected. The throttle surge opening is calculated using these parameters. Based on the relationship between the required throttle opening and the surge opening, the throttle body is controlled to close in stages: when the required throttle opening is less than the surge opening, the throttle body is first closed to the surge opening at a first preset speed. Then, the surge opening is updated in real-time using the throttle intake airflow and engine boost pressure until the required throttle opening is greater than the surge opening, at which point it can be safely closed to the required opening. During this process, after the user releases the accelerator pedal, the vehicle's power demand is lower than before the user released the pedal due to the vehicle's deceleration. Therefore, the throttle body will inevitably move towards a smaller opening, causing the pressure in the intake manifold to increase, resulting in a pressure release requirement and a surge risk in the engine. By precisely controlling or controlling the throttle opening in stages, the throttle valve first closes to the surging opening level, then updates the surging opening until it exceeds the required throttle opening, and then slowly closes to the required opening. This allows for a smooth reduction in intake manifold pressure, achieving stable engine pressure relief. This avoids the surge problems caused by a sudden increase in intake manifold pressure and backflow of airflow that can result from the throttle closing too quickly or directly to a relatively small required opening. Simultaneously, it ensures the engine's power requirements under conditions where fuel cut-off is not permitted, maintaining vehicle operational stability and achieving a balance between surge suppression and operational adaptability in scenarios without a pressure relief valve.

[0038] As one possible implementation of this application, when the throttle valve closes from its current opening to the surge opening, a first preset closing speed is determined based on the opening difference. Preferably, when the opening difference between the two is relatively large, the closing speed of the throttle valve can be controlled to be higher for timely response, that is, the throttle valve can be controlled to close at a faster speed; while when the opening difference between the two is relatively small, it means that the current opening of the throttle valve is close to the surge opening, and at this time, a relatively low speed can be selected to close the throttle valve. On the one hand, this can avoid the throttle valve from being over-closed and causing surge, and on the other hand, the relatively small closing speed of the throttle valve allows the throttle valve to close more smoothly, avoiding large fluctuations in the pressure in the intake manifold caused by the throttle valve closing too quickly, thereby preventing the risk of surge.

[0039] As one possible implementation of this application, see [link to relevant documentation]. Figure 3When the ECU determines that the engine is in a no-fuel-cut-off condition, it calculates and compares the required throttle opening and the throttle surge opening. The required throttle opening is calculated based on the engine's required power. There is a correlation between the engine's required output power and the intake air flow used to output that power, and there is also a correspondence between the engine's intake air flow and the throttle opening. Therefore, the corresponding required throttle opening can be directly calculated based on the engine's required power. The specific calculation process or method can be found in existing engine control logic, which will not be elaborated here. The throttle surge opening refers to the minimum throttle opening when the engine does not surge. This throttle surge opening can be calculated using the current throttle intake air flow, engine boost pressure, and surge curve. Specifically, the engine surge line represents the correspondence between engine intake airflow and the maximum boost pressure without surge. This correspondence is pre-programmed into the ECU, so the ECU can determine the maximum pressure without surge at the current intake airflow rate via the throttle valve, i.e., the surge pressure. For example, the engine surge line can determine the surge pressure corresponding to a certain intake airflow rate. When the boost pressure in the engine intake manifold is higher than this surge pressure, surge will occur. Therefore, the surge pressure corresponding to the current intake airflow is determined by the engine surge line. Then, the corresponding intake airflow is calculated using the pressure difference between the surge pressure and the current boost pressure. This intake airflow represents the adjustable gas flow rate remaining in the intake manifold when the throttle opening is adjusted, assuming the engine is not experiencing surge. In other words, it corresponds to the further reduction in intake airflow when the throttle opening is reduced. Therefore, this intake airflow corresponds to the change in throttle opening. The surge opening of the throttle is then calculated using the change in throttle opening and the current opening. In other words, the surge opening of the throttle is determined by the flow difference between the current intake airflow and the intake airflow corresponding to the pressure difference. When the throttle opening is less than this surge opening, there is a risk of surge or surge may occur. As the throttle gradually closes from its current opening to the surge opening, the throttle opening continuously decreases, resulting in a decrease in the intake airflow through the throttle and a decrease in the exhaust gas produced by engine combustion. This reduces the speed of the turbocharger turbine driven by the exhaust gas, leading to a decrease in the pressure of the compressed gas after turbocharging. This allows for a smooth reduction in engine pressure. As the intake airflow and boost pressure decrease, the calculated throttle surge opening also continuously decreases, thus updating the throttle surge opening. This is a prerequisite for dynamically closing the throttle to a relatively small required opening. In the above calculation process, the calculation of the throttle surge opening is directly related to the engine's core parameters and surge curve, ensuring the accuracy of the calculated throttle surge opening as the minimum opening without surge.When the engine has no pressure relief valve, the precise throttle surge opening provides a reliable threshold for throttle control, which can avoid the risk of surge or excessive throttling caused by the opening calculation deviation, and further prevent surge from occurring.

[0040] As one possible implementation of this application, in addition to using the surge line pre-written in the ECU and the collected throttle intake airflow when calculating the throttle surge opening, the current engine boost pressure is also required. To obtain accurate boost pressure in real time, in this embodiment, a pressure sensor is installed between the intercooler and the throttle valve in the intake manifold to collect the boost pressure in the intake manifold in real time. Choosing to place it between the intercooler and the throttle valve is advantageous because, firstly, the pressure value at this location directly reflects the actual intake pressure at the front of the throttle valve, and compared to other locations such as the turbocharger outlet, it more accurately reflects the changes in the pressure state in the intake manifold caused by throttle valve closure. Secondly, accurate boost pressure is the basis for calculating the throttle surge opening. By using a pressure sensor to collect accurate boost pressure in real time, the accuracy of the calculated throttle surge opening can be ensured, and errors in surge judgment caused by pressure acquisition deviations can be avoided, ensuring an effective solution to the surge problem.

[0041] When the required throttle opening is greater than the throttle surge opening, the required opening is already within a safe range that will not cause surge. Therefore, the throttle opening can be directly adjusted to the required opening without surge. It should be noted that although the ECU needs to calculate the required throttle opening and the throttle surge opening when determining that the engine is in a no-fuel-cut-off condition, the ECU's calculations are at the millisecond level or can be performed at the millisecond level. This allows for rapid output and comparison of the calculation results. Therefore, even if the throttle moves towards a smaller opening during the ECU's calculation and comparison process, it will not close to the throttle surge opening, meaning there is no risk of surge. Therefore, there is no need to pay attention to the current throttle opening during this process; as long as the required throttle opening is large and there is no risk of surge, the throttle can be directly adjusted to the required opening.

[0042] For engine fuel cut-off conditions, see [link / reference]. Figure 3When the user releases the accelerator pedal, the ECU determines that the engine is in a condition where fuel cut-off is permissible. It then determines the engine surge pressure by analyzing the current intake airflow through the throttle and the surge line. The surge pressure is the pressure value corresponding to the current intake airflow on the surge line written into the ECU. At this pressure value, the engine is considered to be on the surge boundary. When the boost pressure is greater than this surge pressure, surge will occur or the risk of surge is high; when the boost pressure is less than this pressure value, surge will not occur or the risk of surge is low. The throttle opening and closing are then controlled based on the relationship between the current boost pressure and the engine surge pressure. Specifically, when the current engine boost pressure is greater than the surge pressure, it indicates a risk of surge. At this time, the throttle is adjusted to its maximum opening, allowing high-pressure gas in the intake manifold to enter the engine's exhaust passage through the throttle and be discharged, thus releasing engine pressure while preventing backflow and surge. When the current boost pressure of the engine is less than the surge pressure, it means that the current boost pressure will not cause surge. At this time, the throttle can be kept closed or closed at the second preset speed. Preferably, the second preset speed is as slow as possible, that is, the throttle is controlled to close at a relatively slow speed to avoid the boost pressure in the intake manifold increasing during the throttle closure process, which could lead to the risk of engine surge.

[0043] It should be noted that when the vehicle is a new energy vehicle with a battery, power compensation, i.e., torque compensation, can be achieved in conjunction with the battery. For example, under conditions where fuel cut-off is not allowed, if the engine boost pressure is greater than the surge pressure, the throttle needs to be maintained at a high opening to avoid surge, resulting in high engine output power. In this case, on the one hand, the battery can output negative torque to offset the excess power output by the engine, ensuring that the vehicle meets the deceleration requirements; on the other hand, the excess power output by the engine can be directly controlled to charge the battery. In addition, under conditions where fuel cut-off is allowed, rapid battery intervention can also reduce the risk of surge when the engine restarts subsequently.

[0044] As one possible implementation of this application, to avoid the risk of surge during engine control, throttle control can also be combined with the vehicle's driver assistance functions. This is especially relevant when the required throttle opening is less than the throttle surge opening under conditions where engine fuel cut-off is prohibited. Specifically, by acquiring information about the road conditions ahead of the vehicle, the vehicle's power demand for a preset period and the corresponding future required throttle opening are predicted. If the future required opening is greater than the throttle surge opening, the throttle can be directly adjusted to the future required opening. For example, when a user drives the vehicle over a speed bump, releases the accelerator pedal, and then suddenly brakes, the required throttle opening rapidly decreases to below the throttle surge opening. The vehicle's driver assistance function determines that the user is driving over the speed bump and that there is a high probability that the user will press the accelerator pedal after driving over the speed bump, causing the future required throttle opening to be greater than the throttle surge opening. In this case, the throttle can be directly adjusted to the future required opening. This approach avoids frequent throttle adjustments in a short period due to driving scenarios such as going over speed bumps or turning, reducing repeated movements of the throttle near the surge opening and lowering the risk of surge caused by pressure fluctuations. It also proactively meets the vehicle's future power demands, improving driving smoothness and stability. However, if the future demand opening is still less than the throttle surge opening, the throttle will be normally controlled to close to the surge opening first. The surge opening will then be updated until the demand opening exceeds the surge opening, at which point the throttle will be safely closed to the demand opening.

[0045] The engine control method provided in this application, through a throttle anti-surge strategy, can effectively control or adjust the throttle intake airflow, ensuring that the engine operating conditions are always within the turbocharger surge line, thereby preventing the turbocharger from entering the surge region, achieving anti-surge, and effectively protecting the turbocharger from damage. Simultaneously, when the anti-surge strategy is activated, the ECU precisely controls the throttle opening for pressure relief, achieving a smoother and quieter pressure release process, avoiding user-perceived pressure relief noise and thus improving the user experience, while also further optimizing the overall vehicle NVH performance.

[0046] It should be noted that the surge curve used in the engine control strategy proposed in this application is a curve measuring the relationship between intake airflow and surge pressure, measured at the vehicle's factory, and pre-programmed into the ECU for querying and recall. Of course, vehicle manufacturers can modify the pre-programmed surge curve in the ECU based on the vehicle's sales or usage location, or the ECU can automatically modify it by incorporating parameters such as engine coolant temperature, altitude, and turbocharger speed. For example, in high-altitude areas where the air is thin, the surge pressure will be lower for the same intake airflow. Dynamically adjusting the surge curve using altitude sensor data makes the calculation of throttle surge opening more accurate, thereby improving the anti-surge effect.

[0047] The above are method embodiments of this application. Based on the same inventive concept, this application also provides a vehicle engine control device, the structure of which is as follows: Figure 4 As shown.

[0048] Figure 4 This is a schematic diagram of an engine control device provided for this application / an embodiment of this application. Figure 4 As shown, the device includes: at least one processor 401; and a memory 402 communicatively connected to the at least one processor 401 (e.g., connected via a bus); wherein the memory 402 stores instructions executable by the at least one processor, which are executed by the at least one processor 401 to enable the at least one processor 401 to perform a vehicle engine control method as described in any of the above possible embodiments.

[0049] In one possible implementation of this application, the aforementioned processor 401 is capable of executing the following actions in response to the release of the accelerator pedal: determining whether the engine is in a no-fuel-cut-off condition; if so, determining the required throttle opening based on the engine's required power, and calculating the throttle surge opening based on the current throttle intake flow and the current engine boost pressure; wherein the throttle surge opening is the minimum opening of the throttle corresponding to the engine not surging under the current engine boost pressure; when the required throttle opening is less than the throttle surge opening, controlling the throttle to close at a first preset speed, and updating the current throttle intake flow and the current engine boost pressure to update the throttle surge opening when the throttle closes to the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and controlling the throttle to close to the required throttle opening at the first preset speed.

[0050] In addition, this application also provides a vehicle, which includes at least an engine and the aforementioned engine control equipment. Alternatively, the vehicle may also include an engine and an engine control system. The engine control system contains computer-executable instructions. When these instructions are executed, the engine performs the following actions: In response to the release of the accelerator pedal, it determines whether the engine is in a no-fuel-cut-off condition; if so, it determines the required throttle opening based on the engine's required power and calculates the throttle surge opening based on the current throttle intake flow and the current engine boost pressure; wherein the throttle surge opening is the minimum opening of the throttle corresponding to the engine not surging under the current engine boost pressure; when the required throttle opening is less than the required throttle surge opening, it controls the throttle to close at a first preset speed, and when the throttle closes to the required throttle surge opening, it updates the current throttle intake flow and the current engine boost pressure to update the throttle surge opening, until the throttle surge opening is less than the required throttle opening, and then controls the throttle to close to the required throttle opening at the first preset speed.

[0051] This application can also divide the vehicle into functional modules according to the above method examples. For example, each module can correspond to a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and is only a logical functional division. In actual implementation, there may be other division methods.

[0052] When each functional module is divided according to its corresponding function, the vehicle may include: a judgment module, a control module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0053] The vehicle provided in this embodiment is used to execute the engine control method described above, and therefore can achieve the same effect as the above implementation method.

[0054] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's actions. The storage module supports the vehicle in executing program code and data.

[0055] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits as disclosed in this application. The processor may also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0056] This application may also provide a computer-readable storage medium (including but not limited to disk storage, CD-ROM, optical storage, etc.) storing computer program code. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the engine control method provided in the above embodiments.

[0057] This application also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement the engine control method provided in the above embodiments. The beneficial effects of the above embodiments can be found in the corresponding methods described above, and will not be repeated here.

[0058] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0059] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0060] In the description of this application, it should be understood that if the terms "upper", "lower", "front", "rear", "left" and "right" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0062] The above are merely embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An engine control method, characterized in that, Applied to vehicles, the method includes: In response to the release of the vehicle's accelerator pedal, determine whether the engine is in a condition where fuel cut-off is prohibited; If so, the required throttle opening is determined by the engine's required power, and the throttle surge opening is calculated based on the current intake airflow and the current boost pressure of the engine; wherein, the throttle surge opening is the minimum opening of the throttle corresponding to the engine not surging under the current boost pressure of the engine; When the required throttle opening is less than the required throttle surge opening, the throttle is controlled to close at a first preset speed. When the throttle closes to the required throttle surge opening, the current intake airflow of the throttle and the current boost pressure of the engine are updated to update the required throttle surge opening. This process continues until the required throttle surge opening is less than the required throttle opening, at which point the throttle is controlled to close to the required throttle opening at the first preset speed.

2. The engine control method according to claim 1, characterized in that, The throttle surge opening is calculated based on the current intake airflow and engine boost pressure, including: Determine the engine surge pressure corresponding to the current intake airflow at the throttle valve based on the engine surge line; Calculate the pressure difference between the engine surge pressure and the current engine boost pressure, and calculate the intake air flow rate corresponding to the pressure difference; The throttle surge opening is determined by the flow difference between the engine's current intake airflow and the intake airflow corresponding to the pressure difference.

3. The engine control method according to claim 1, characterized in that, Controlling the throttle valve to close at a first preset speed includes: The first preset speed for throttle closing is determined based on the difference between the current throttle opening and the throttle surge opening.

4. The engine control method according to claim 1, characterized in that, After obtaining the required throttle opening and the throttle surge opening, the method further includes: Determine that the required throttle opening is greater than the throttle surge opening; Control the throttle valve to adjust to the required throttle valve opening.

5. The engine control method according to claim 1, characterized in that, The current boost pressure of the engine is obtained by a preset pressure sensor, which is located inside the engine intake manifold and between the intercooler and the throttle valve.

6. The engine control method according to claim 1, characterized in that, In response to the release of the accelerator pedal, determining whether the engine is in a condition where fuel cut-off is prohibited also includes: The engine is confirmed to be in a condition where fuel cut-off is permissible; Determine the current intake airflow at the throttle body and the current boost pressure of the engine; Determine the engine surge pressure corresponding to the current intake airflow at the throttle valve based on the engine surge line; The opening and closing of the throttle valve are controlled by the current boost pressure and surge pressure of the engine.

7. The engine control method according to claim 6, characterized in that, Controlling the opening and closing of the throttle valve based on the current boost pressure and surge pressure of the engine includes: If the current boost pressure of the engine is greater than the engine surge pressure, then control the throttle valve to adjust to its maximum opening. If the current boost pressure of the engine is less than the engine surge pressure, then the throttle valve is controlled to remain closed or the throttle valve is controlled to close at a second preset speed.

8. The engine control method according to claim 1, characterized in that, When the required throttle opening is less than the throttle surge opening, the method further includes: Obtain road condition information ahead of the vehicle, and determine the future power demand within a preset time period based on the road condition information ahead of the vehicle. Determine the future throttle opening corresponding to the future power demand; If the future required throttle opening is greater than the throttle surge opening, then the throttle is controlled to adjust to the future required throttle opening.

9. A control device, characterized in that, The control device includes: At least one processor; And, a memory communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform an engine control method as described in any one of claims 1-8.

10. A vehicle, characterized in that, It includes an engine and the control device as described in claim 9.

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