Engine protection method, system and storage medium in braking condition

Abstract

The application provides an engine protection method and system in a braking condition and a storage medium, and relates to the technical field of vehicle in-cylinder braking. The method is applied to a vehicle controller and comprises the following steps: acquiring engine condition information; performing condition judgment according to the engine condition information, so as to acquire a post-intercooling pressure value when it is detected that the current condition is a braking condition, and determine a first intake pressure value according to the engine condition information, a preset first required braking power and a second prestored characteristic curve; and when it is detected that the post-intercooling pressure value is greater than the first intake pressure value, performing in-cylinder braking operation according to a third prestored characteristic curve, so as to realize the adjustment of the braking power by only controlling the air quantity through the opening degree of the intake throttle valve. According to the method, when the exhaust gas bleeding valve of the turbocharger fails, the control mode of the in-cylinder braking can be switched in time, the engine is prevented from being damaged, and meanwhile, the user can continue to normally use the in-cylinder braking function of the engine.

Description

Technical Field

[0001] This application relates to the field of vehicle cylinder braking technology, and in particular to an engine protection method, system and storage medium under braking conditions. Background Technology

[0002] When the exhaust gas vent valve of the turbocharger malfunctions, such as an open air supply line or abnormal venting function, it will prevent the engine from venting properly under in-cylinder braking conditions, thereby causing engine damage due to excessive in-cylinder pressure.

[0003] In existing technologies, when a faulty exhaust valve is detected, the engine is typically protected by reducing the in-cylinder braking performance or completely disengaging the in-cylinder braking mode, and damage to the engine is avoided by immediately performing professional inspection and repair.

[0004] However, while this method can avoid engine damage, it will affect the user's normal use of the engine's in-cylinder braking function. Summary of the Invention

[0005] This application provides an engine protection method, system, and storage medium under braking conditions, which can prevent engine damage by switching the control mode of in-cylinder braking in a timely manner when the exhaust gas valve of the turbocharger malfunctions, while ensuring that the user can continue to use the engine's in-cylinder braking function normally.

[0006] In a first aspect, this application provides an engine protection method under braking conditions, which is applied to a vehicle controller and includes:

[0007] Obtain engine operating condition information;

[0008] The operating condition is determined based on the engine operating condition information. When the current operating condition is detected to be braking, the pressure value after the intercooler is obtained, and the first intake pressure value is determined based on the engine operating condition information, the preset first required braking power and the second pre-stored universal characteristic curve.

[0009] When the intercooler pressure value is detected to be greater than the first intake pressure value, the cylinder braking operation is performed according to the third pre-stored universal characteristic curve, so as to adjust the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0010] In one possible design, engine operating condition information includes engine throttle opening information, gear information, engine speed information, and brake switch status information.

[0011] Accordingly, operating condition judgment is performed based on engine operating condition information. When braking condition is detected as the current operating condition, the intercooler pressure value is obtained, including:

[0012] The system determines whether the throttle opening is 0 based on the engine throttle opening information, whether the gear is in gear based on the gear information, whether the engine speed is greater than the preset speed threshold based on the engine speed information, and whether the in-cylinder brake switch is open based on the brake switch status information.

[0013] When the throttle opening is 0, the gear is in gear, the engine speed is greater than the preset speed threshold, and the in-cylinder brake switch is on, the intercooler pressure value is obtained.

[0014] In one possible design, engine operating condition information includes engine speed information;

[0015] Based on engine operating condition information, the preset first required braking power, and the second pre-stored universal characteristic curve, the first intake pressure value is determined, including:

[0016] Based on the engine speed information, extract the undetermined intake pressure value and undetermined engine braking power corresponding to the engine speed information from the second pre-stored universal characteristic curve.

[0017] When the detected engine braking power is less than the preset first required braking power, the detected intake pressure value is determined as the first intake pressure value.

[0018] In one possible design, when the intercooler pressure is detected to be greater than the first intake pressure, in-cylinder braking is performed according to the third pre-stored universal characteristic curve. This achieves braking power adjustment by controlling the intake throttle valve opening to control the air volume, including:

[0019] When the intercooler pressure is detected to be greater than the first intake pressure, the intake throttle valve closed-loop control strategy is selected according to the third pre-stored universal characteristic curve to perform in-cylinder braking operation. The exhaust gas release valve controls the air volume, which is then switched to the intake throttle valve. This allows the intake throttle valve to control the intercooler pressure in a closed loop to control the braking power, thereby adjusting the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0020] In one possible design, the method also includes:

[0021] When the intercooler pressure is detected to be lower than the first intake pressure, the cylinder braking operation is performed according to the first pre-stored universal characteristic curve, so as to adjust the braking power by controlling the opening of the exhaust gas release valve.

[0022] In one possible design, the method also includes:

[0023] When the intercooler pressure value is detected to be equal to the first intake pressure value, the in-cylinder braking operation is performed according to the second pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the amount of gas only by controlling the exhaust gas release valve.

[0024] In one possible design, the method also includes:

[0025] The vehicle controller sends a warning command to the instrument panel, so that the instrument panel can issue a warning message based on the warning command.

[0026] Secondly, this application provides an engine protection system under braking conditions, the system including: a vehicle controller, an exhaust gas release valve, an intake throttle valve and an in-cylinder pressure sensor;

[0027] Among them, the vehicle controller is connected to the exhaust gas release valve, intake throttle valve and cylinder pressure sensor, and the vehicle controller communicates with the vehicle control unit through the vehicle bus.

[0028] The vehicle controller is used to acquire engine operating condition information; it makes operating condition judgments based on the engine operating condition information, and when the current operating condition is detected to be braking, it acquires the intercooler pressure value and determines the first intake pressure value based on the engine operating condition information, the preset first required braking power and the second pre-stored universal characteristic curve; when the intercooler pressure value is detected to be greater than the first intake pressure value, it performs in-cylinder braking operation according to the third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0029] In one possible design, the system also includes: instruments;

[0030] The instrument cluster is connected to the vehicle controller for data transmission. The instrument cluster is used to receive warning commands sent by the vehicle controller and to send warning information according to the warning commands.

[0031] Thirdly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a vehicle controller, are used to implement an engine protection method under braking conditions as described in the first aspect of the invention.

[0032] Fourthly, this application provides a computer program product, including a computer program, which, when executed by a vehicle controller, is used to implement an engine protection method under braking conditions as described in the first aspect of the invention.

[0033] Based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods.

[0034] This application provides an engine protection method, system, and storage medium under braking conditions. The method is applied to a vehicle controller and includes: first, acquiring engine operating condition information; then, judging the operating condition based on the engine operating condition information, such that when the current operating condition is detected as braking, the intercooler pressure value is acquired, and a first intake pressure value is determined based on the engine operating condition information, a preset first required braking power, and a second pre-stored universal characteristic curve; then, when the intercooler pressure value is detected to be greater than the first intake pressure value, an in-cylinder braking operation is performed according to a third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve. The following technical effects are achieved: When the vehicle's engine is under braking conditions, the intercooler pressure value is detected and compared with the intake pressure identified from the second pre-stored universal characteristic curve. When the intercooler pressure value is detected to be greater than the first intake pressure value, it is determined that the cylinder pressure exceeds the safe cylinder pressure limit. To avoid the exhaust gas venting valve malfunction affecting the in-cylinder braking function, in-cylinder braking is performed according to the third pre-stored universal characteristic curve. By timely switching the control method of in-cylinder braking from controlling the cylinder air volume through the exhaust gas venting valve to controlling the cylinder air volume through the intake throttle valve, engine damage is avoided while ensuring that the user can continue to use the engine's in-cylinder braking function normally. Through optimized control strategies, a reliable solution is provided without affecting the engine's in-cylinder braking performance. This not only improves the safety and reliability of vehicle operation but also enhances the user experience and reduces unnecessary downtime. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 This application provides a schematic diagram of the structure of an engine protection system under braking conditions, as shown in the embodiments of the present application.

[0038] Figure 2 A flowchart illustrating an engine protection method under braking conditions provided in this application embodiment. Figure 1 ;

[0039] Figure 3A flowchart illustrating an engine protection method under braking conditions provided in this application embodiment. Figure 2 .

[0040] Figure label:

[0041] 10-Vehicle controller; 20-Exhaust gas release valve; 30-Intake throttle valve; 40-In-cylinder pressure sensor; 50-Engine; 201-Engine exhaust pipe; 202-Turbine; 203-Compressor; 301-Engine intake manifold; 302-Intercooler; 501-Cylinder. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0043] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply difference. It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in this application should not be construed as being better or more advantageous than other embodiments or design schemes. Specifically, the use of "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner. In the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more.

[0044] It should be noted that the phrase "at...time" in the embodiments of this application can refer to the instant at which a certain situation occurs, or to a period of time after the occurrence of a certain situation; the embodiments of this application do not specifically limit this. Furthermore, the engine protection method under braking conditions provided in the embodiments of this application is merely an example; an engine protection method under braking conditions may include more or fewer elements.

[0045] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0046] In-cylinder braking is a technology that uses the pressure generated in the engine's combustion chamber to produce braking force. By controlling the working process within the engine cylinders, the normal combustion process is stopped, and instead a compression-release cycle is established to generate braking force on the vehicle. Specifically, during the engine's compression stroke, the piston moves upward and compresses the air in the cylinder. During this time, the exhaust valve remains closed, preventing the compressed air entering the cylinder during the compression stroke from being properly expelled. As the piston approaches top dead center, the exhaust valve opens prematurely, and the compressed air is rapidly released into the exhaust system, causing a sharp drop in cylinder pressure. This results in energy being wasted at the end of each compression stroke. Because the energy of the compressed air is released prematurely, the piston cannot obtain enough energy to drive the crankshaft during the subsequent power stroke, thus consuming the vehicle's kinetic energy and achieving a braking effect.

[0047] Compression-release in-cylinder braking typically controls cylinder pressure primarily by regulating the exhaust gas release valve. When the turbocharger's exhaust gas release valve (also known as the wastegate or pressure relief valve) malfunctions, such as an open circuit in the air supply line or abnormal exhaust function, it can cause the in-cylinder braking system to fail to exhaust properly. Once the exhaust from the in-cylinder braking system is obstructed, the pressure inside the engine cylinders will abnormally increase, causing serious damage to the engine.

[0048] The traditional solution is to reduce the performance level of the in-cylinder braking system or directly disengage the in-cylinder braking mode when a malfunction of the exhaust gas release valve is detected. While these methods can prevent engine damage, they limit the user's ability to use the in-cylinder braking function normally, causing considerable inconvenience.

[0049] Based on this, this application proposes an engine protection method, system, and storage medium under braking conditions, which can be used in the field of vehicle in-cylinder braking technology, aiming to solve the above-mentioned technical problems of the prior art. By switching the control mode of in-cylinder braking in a timely manner when the exhaust gas release valve of the turbocharger fails, the air volume is switched from being controlled by the exhaust gas release valve to being controlled by the intake throttle valve. While ensuring that the engine is not damaged, it ensures that the user can continue to use the engine's in-cylinder braking function normally, achieving a dual improvement in engine protection and user experience.

[0050] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0051] Figure 1 This is a schematic diagram of an engine protection system under braking conditions provided in an embodiment of this application. Figure 1As shown, the system includes: a vehicle controller 10, an exhaust gas release valve 20, an intake throttle valve 30, and an in-cylinder air pressure sensor 40.

[0052] The vehicle controller 10 is connected to the exhaust gas release valve 20, the intake throttle valve 30 and the in-cylinder air pressure sensor 40. The vehicle controller 10 is also connected to the vehicle control unit via the vehicle bus.

[0053] The vehicle controller 10 is used to acquire engine operating condition information; to determine the operating condition based on the engine operating condition information; when the current operating condition is detected to be braking, it acquires the intercooler pressure value and determines the first intake pressure value based on the engine operating condition information, the preset first required braking power and the second pre-stored universal characteristic curve; when the intercooler pressure value is detected to be greater than the first intake pressure value, it performs in-cylinder braking operation according to the third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve 30.

[0054] Specifically, such as Figure 1 As shown, the exhaust gas release valve 20 is located on the engine exhaust pipe 201. The turbocharger turbine 202 is connected to the exhaust system of the engine 50, using the kinetic energy of the exhaust gas to drive the turbine blades to rotate. The turbine 202 is connected to the compressor 203 via a mechanical shaft. The compressor 203 is located in the intake system of the engine 50 and is responsible for compressing outside air and sending it into the cylinder 501 of the engine 50. Figure 1 The engine 50 includes six cylinders 501 as an example only. In practical applications, the engine 50 may include more or fewer cylinders 501. The intake throttle valve 30 is located on the engine intake manifold 301, and an intercooler 302 is also provided on the engine intake manifold 301.

[0055] like Figure 1 As shown, the vehicle controller 10 can be wired to the exhaust gas release valve 20, the intake throttle valve 30, and the in-cylinder pressure sensor 40, respectively. In other implementations, wireless connections can also be used; no specific limitation is made here. Similarly, the vehicle controller 10 can also be wired or wirelessly connected to the vehicle control unit via the vehicle bus to obtain the intercooler pressure value from the pressure sensor at the engine 50 through the vehicle control unit.

[0056] Specifically, the vehicle controller 10 can acquire engine operating condition information and make operating condition judgments based on this information. When the current operating condition is detected as braking, the vehicle control unit obtains the intercooler pressure value from the pressure sensor at the engine 50 and determines the first intake pressure value based on the engine operating condition information, the preset first required braking power, and the second pre-stored universal characteristic curve. Then, when the intercooler pressure value is detected to be greater than the first intake pressure value, it is confirmed that the turbocharger's exhaust gas release valve 20 has malfunctioned. In this case, in-cylinder braking is performed according to the third pre-stored universal characteristic curve, so that the braking power is adjusted by controlling the air volume solely by controlling the opening of the intake throttle valve 30. By timely switching the control mode of in-cylinder braking from exhaust gas release valve 20 to intake throttle valve 30, the in-cylinder braking function of the engine 50 can be continued to be used normally while protecting the engine 50 from damage, thus achieving a dual improvement in engine protection and user experience.

[0057] Furthermore, the system also includes: instruments;

[0058] The instrument is connected to the vehicle controller 10 for data transmission. The instrument is used to receive warning commands sent by the vehicle controller 10 and send warning information according to the warning commands to remind the user that the exhaust gas release valve 20 has malfunctioned and the pressure in the cylinder 501 of the engine 50 is too high. The system has switched to adjusting the braking power by controlling the air volume only by controlling the opening of the intake throttle valve 30.

[0059] The technical solution of this application will be described in detail below with reference to specific embodiments. Figure 2 A flowchart illustrating an engine protection method under braking conditions provided in this application embodiment. Figure 1 .like Figure 2 As shown, the method includes:

[0060] S201. Obtain engine operating condition information.

[0061] In this embodiment, an engine protection method under braking conditions is applied to a vehicle controller. Engine operating condition information may include: engine throttle opening information, gear information, engine speed information, and brake switch status information.

[0062] Specifically, the vehicle controller can continuously monitor engine operating information to determine whether the current engine operating condition is braking condition based on engine throttle opening information, gear information, engine speed information, and brake switch status information.

[0063] S202. Based on the engine operating condition information, determine the operating condition. When the current operating condition is detected to be braking, obtain the intercooler pressure value and determine the first intake pressure value based on the engine operating condition information, the preset first required braking power, and the second pre-stored universal characteristic curve.

[0064] Specifically, when the vehicle controller detects that the engine is in braking condition, it can further obtain the current intercooler pressure value from the pressure sensor at the engine through the vehicle control unit. Since the intake pressure after intercooling is the same as the pressure inside the engine cylinder, it can directly affect the amount of air entering the cylinder. Therefore, the vehicle controller can determine whether the cylinder pressure (pressure inside the cylinder) of the engine is too high based on the intercooler pressure value, and thus determine whether the exhaust gas vent valve of the turbocharger has a fault such as an open air supply line or abnormal exhaust function.

[0065] Specifically, the vehicle controller has three pre-stored universal characteristic curves, all of which are three-dimensional performance parameter graphs of braking power, intake pressure, and engine speed. The first pre-stored universal characteristic curve is the braking calibration data for the current vehicle when the cylinder pressure is adjusted solely by regulating the opening of the exhaust gas vent valve. The second pre-stored universal characteristic curve is the safety baseline for the current vehicle when the cylinder pressure is controlled solely by regulating the opening of the exhaust gas vent valve to prevent the engine cylinder from exceeding the safe cylinder pressure limit. The third pre-stored universal characteristic curve is the braking data calibrated by the vehicle controller without invoking the exhaust gas vent valve, but only by adjusting the opening of the intake throttle valve to control the cylinder pressure. In the first and second pre-stored universal characteristic curves, there is a corresponding relationship between the braking power of the engine cylinder braking, the pressure inside the engine cylinder, and the opening degree of the exhaust gas release valve; in the third pre-stored universal characteristic curve, there is a corresponding relationship between the braking power of the engine cylinder braking, the pressure inside the engine cylinder, and the opening degree of the intake throttle valve.

[0066] In this embodiment of the application, the preset first required braking power refers to the preset target braking intensity, which is a preset upper limit power threshold in the second pre-stored universal characteristic curve.

[0067] The vehicle controller can identify the corresponding intake pressure from the second pre-stored universal characteristic curve based on the engine speed information and the preset first required braking power, and use this pressure as the first intake pressure value.

[0068] S203. When the intercooler pressure value is detected to be greater than the first intake pressure value, the cylinder braking operation is performed according to the third pre-stored universal characteristic curve, so as to adjust the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0069] Specifically, when the intercooler pressure exceeds the first intake pressure, the vehicle controller determines that the cylinder pressure exceeds the safe cylinder pressure limit. This indicates a fault in the turbocharger's exhaust gas valve, such as an open circuit in the supply line or abnormal exhaust function. The controller then initiates in-cylinder braking according to the third pre-stored universal characteristic curve. This involves controlling the cylinder volume and pressure solely by adjusting the intake throttle valve opening, thereby adjusting the braking power of the in-cylinder braking system. By promptly switching the in-cylinder braking control method from controlling the cylinder volume via the exhaust gas valve to controlling it via the intake throttle valve, and adjusting the intake pressure, engine damage is avoided while ensuring the user can continue to use the engine's in-cylinder braking function normally.

[0070] This embodiment provides an engine protection method under braking conditions, applied to a vehicle controller. The method includes: first, acquiring engine operating condition information; then, judging the operating condition based on the engine operating condition information, such that when the current operating condition is detected as braking, the intercooler pressure value is acquired, and a first intake pressure value is determined based on the engine operating condition information, a preset first required braking power, and a second pre-stored universal characteristic curve; then, when the intercooler pressure value is detected to be greater than the first intake pressure value, an in-cylinder braking operation is performed according to a third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0071] The following technical effects are achieved: When the vehicle's engine is under braking conditions, the intercooler pressure value is detected and compared with the intake pressure identified from the second pre-stored universal characteristic curve. When the intercooler pressure value is detected to be greater than the first intake pressure value, it is determined that the cylinder pressure exceeds the safe cylinder pressure limit. To avoid the exhaust gas venting valve malfunction affecting the in-cylinder braking function, in-cylinder braking is performed according to the third pre-stored universal characteristic curve. By timely switching the control method of in-cylinder braking from controlling the cylinder air volume through the exhaust gas venting valve to controlling the cylinder air volume through the intake throttle valve, engine damage is avoided while ensuring that the user can continue to use the engine's in-cylinder braking function normally. Through optimized control strategies, a reliable solution is provided without affecting the engine's in-cylinder braking performance. This not only improves the safety and reliability of vehicle operation but also enhances the user experience and reduces unnecessary downtime.

[0072] Figure 3 A flowchart illustrating an engine protection method under braking conditions provided in this application embodiment. Figure 2 In one possible example, such as Figure 3 As shown, in this embodiment... Figure 2Based on the embodiments, a detailed explanation is provided on how to control the air volume solely by controlling the opening of the intake throttle valve. For example... Figure 3 As shown, the method includes:

[0073] S301, Obtain engine operating condition information.

[0074] S301 is similar to S201, and will not be described again in this embodiment.

[0075] S302. Determine whether the throttle opening is 0 based on the engine throttle opening information, determine whether the gear is in gear based on the gear information, determine whether the engine speed is greater than the preset speed threshold based on the engine speed information, and determine whether the in-cylinder brake switch is open based on the brake switch status information.

[0076] Specifically, when the vehicle controller determines that the engine has entered braking mode, it needs to check whether the engine operating condition information simultaneously meets the following four conditions, as follows:

[0077] First, by acquiring the engine throttle opening information (throttle sensor signal), it is determined whether the throttle opening is 0. This ensures that the driver has no acceleration need and has not pressed the accelerator pedal, confirming that the vehicle is in a non-accelerating state to avoid conflict between the in-cylinder braking function and vehicle acceleration. Furthermore, during this process, the vehicle controller can filter the throttle sensor signal to prevent the in-cylinder braking function from being mistakenly triggered due to vehicle vibration.

[0078] Secondly, by reading the status signals of the transmission or shift mechanism, the system determines whether the gear is in gear based on the gear information, thus confirming that the transmission is currently in gear and not in neutral. Only when the transmission is in gear can the intra-cylinder braking apply braking force to the wheels through the transmission system, thereby preventing the intra-cylinder braking function from being accidentally activated when coasting in neutral.

[0079] Next, the engine speed sensor signal is read and compared with a preset speed threshold in the system. The system determines whether the engine speed exceeds the preset threshold to ensure that the engine speed reaches a certain level (greater than the preset threshold), thereby guaranteeing the effectiveness of in-cylinder braking and preventing stalling or torque fluctuations caused by braking at low speeds. If the engine speed is too low, the effectiveness of in-cylinder braking will be affected. The preset speed threshold can be 1200 revolutions per minute (RPM), or it can be set according to the engine characteristics of different vehicles; no specific limitation is made here.

[0080] Then, by reading the status information of the brake switch, it is determined whether the in-cylinder brake switch is in the open state to confirm that the driver has activated the in-cylinder braking function. S303, when it is detected that the throttle opening is 0, the gear is in gear, the engine speed is greater than the preset speed threshold, and the in-cylinder brake switch is open, the intercooler pressure value is obtained.

[0081] Specifically, when all four conditions are met—that is, the throttle opening is 0, the gear is in gear, the engine speed is greater than the preset speed threshold, and the in-cylinder brake switch is in the open state—the vehicle controller can confirm that the engine's current operating condition is braking condition. It can then further obtain the current intercooler pressure value to determine whether the air pressure in the engine cylinder exceeds the safe cylinder pressure limit.

[0082] S304. Based on the engine speed information, extract the undetermined intake pressure value and the undetermined engine braking power corresponding to the engine speed information from the second pre-stored universal characteristic curve.

[0083] Specifically, to obtain the safe cylinder pressure limit for the current vehicle at the current engine speed, the vehicle controller first searches for two key parameters corresponding to that engine speed in the second pre-stored universal characteristic curve, based on the engine speed information. These two parameters are: the undetermined intake pressure value and the undetermined engine braking power. The undetermined intake pressure value refers to the maximum intake pressure value of the calibrated engine cylinder that does not exceed the safe cylinder pressure limit at the current engine speed; the undetermined engine braking power refers to the braking power that the engine can output under the conditions of the current engine speed and the undetermined intake pressure value.

[0084] S305. When the engine braking power to be determined is detected to be less than the preset first required braking power, the to be determined intake pressure value is determined as the first intake pressure value.

[0085] Specifically, when the vehicle controller detects that the pending engine braking power extracted from the second pre-stored universal characteristic curve is less than the preset first required braking power, the pending intake pressure value is determined as the first intake pressure value.

[0086] S306. When the intercooler pressure value is detected to be greater than the first intake pressure value, the intake throttle valve closed-loop control strategy is selected according to the third pre-stored universal characteristic curve to perform in-cylinder braking operation. The exhaust gas release valve controls the air volume, which is then switched to the intake throttle valve. This allows the intake throttle valve to control the intercooler pressure in a closed loop to control the braking power, thereby adjusting the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0087] Specifically, when the vehicle controller detects that the intercooler pressure is greater than the first intake pressure, it can be determined that the cylinder pressure exceeds the safe cylinder pressure limit. To prevent a malfunction of the exhaust gas release valve from affecting the in-cylinder braking function, the in-cylinder braking operation can be performed using a closed-loop control strategy via the intake throttle valve, according to the third pre-stored universal characteristic curve. By switching the control of cylinder air volume from the exhaust gas release valve to the intake throttle valve, the intercooler pressure can be controlled via the intake throttle valve, thereby achieving closed-loop control of braking power. This allows for adjustment of braking power solely by controlling the intake throttle valve opening to regulate air volume.

[0088] By using the intake throttle valve to control the amount of air in the cylinder only when the exhaust gas venting valve line is faulty or malfunctioning, the frequency of use of the intake throttle valve during in-cylinder braking can be reduced, thereby reducing the cost of using the intake throttle valve and reducing the possibility of damage to the intake throttle valve.

[0089] S307. When the intercooler pressure value is detected to be less than the first intake pressure value, the cylinder braking operation is performed according to the first pre-stored universal characteristic curve, so as to adjust the braking power by controlling the opening of the exhaust gas release valve.

[0090] Specifically, when the vehicle controller detects that the intercooler pressure is lower than the first intake pressure, it can determine that the cylinder pressure has not exceeded the safe cylinder pressure limit, and the exhaust gas release valve can function normally. The vehicle controller can then perform in-cylinder braking operation according to the first pre-stored universal characteristic curve through the exhaust gas release valve closed-loop control strategy, thereby adjusting the braking power solely by controlling the opening of the exhaust gas release valve.

[0091] S308. When the intercooler pressure value is detected to be equal to the first intake pressure value, the cylinder braking operation is performed according to the second pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the amount of gas only by controlling the exhaust gas release valve.

[0092] Specifically, when the vehicle controller detects that the intercooler pressure value equals the first intake pressure value, it can be determined that the air pressure inside the engine cylinder has not exceeded the safe cylinder pressure limit, and the exhaust gas release valve can work normally. The vehicle controller can continue to perform in-cylinder braking operation according to the second pre-stored universal characteristic curve through the exhaust gas release valve closed-loop control strategy, thus still adjusting the braking power only by controlling the opening size of the exhaust gas release valve.

[0093] Furthermore, the method may also include: sending a warning command to the instrument via the vehicle controller, so that the instrument issues a warning message according to the warning command, thereby reminding the user that the exhaust gas release valve is malfunctioning, the pressure in the engine cylinder is too high, and the system has switched to adjusting the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

[0094] This application provides an engine protection method under braking conditions. By using only the exhaust gas venting valve or only the intake throttle valve for in-cylinder braking, the design and control logic of the engine protection system under braking conditions can be simplified, reducing the complexity and potential failure points of the entire system. By using the intake throttle valve to control the cylinder air volume only when the exhaust gas venting valve pipeline is faulty or malfunctioning, the operating frequency of the intake throttle valve during in-cylinder braking can be reduced, thereby reducing the wear rate of the intake throttle valve, extending its service life, and reducing its maintenance costs. When the intercooling pressure value is not greater than the first intake pressure value, the exhaust gas venting valve is used preferentially for in-cylinder braking, which can affect the engine's operating state more quickly. This is because the exhaust gas venting valve directly affects the working efficiency of the turbocharger, and the turbocharger has a more direct impact on engine performance, thus enabling faster in-cylinder braking.

[0095] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by the vehicle controller, are used to implement the engine protection method or driving behavior recognition method under braking conditions as described above.

[0096] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0097] An exemplary readable storage medium is coupled to a vehicle controller, enabling the vehicle controller to read information from and write information to the readable storage medium. Alternatively, the readable storage medium can be an integral part of the vehicle controller. Both the vehicle controller and the readable storage medium can reside in application-specific integrated circuits (ASICs). Alternatively, the vehicle controller and the readable storage medium can exist as discrete components within an electronic device or main control unit.

[0098] This application also provides a computer program product, which includes a computer program stored in a readable storage medium. The vehicle controller can read the computer program from the readable storage medium and execute the computer program to implement the solution provided in the above embodiments.

[0099] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disk, or optical disk.

[0100] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for protecting an engine under braking conditions, characterized in that, Applied to a vehicle controller, the method includes: Obtain engine operating condition information; The engine operating condition is determined based on the engine operating condition information. When the current operating condition is detected to be braking, the intercooler pressure value is obtained, and the first intake pressure value is determined based on the engine operating condition information, the preset first required braking power and the second pre-stored universal characteristic curve. When the intercooler pressure value is detected to be greater than the first intake pressure value, the in-cylinder braking operation is performed according to the third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve. The engine operating condition information includes engine speed information; The step of determining the first intake pressure value based on the engine operating condition information, the preset first required braking power, and the second pre-stored universal characteristic curve includes: Based on the engine speed information, extract the undetermined intake pressure value and undetermined engine braking power corresponding to the engine speed information from the second pre-stored universal characteristic curve. When the engine braking power to be determined is detected to be less than the preset first required braking power, the engine braking power to be determined is determined as the first intake pressure value. When the intercooler pressure value is detected to be greater than the first intake pressure value, an in-cylinder braking operation is performed according to the third pre-stored universal characteristic curve to achieve braking power adjustment by controlling the air volume solely by controlling the intake throttle valve opening, including: When the intercooler pressure value is detected to be greater than the first intake pressure value, the intake throttle valve closed-loop control strategy is selected according to the third pre-stored universal characteristic curve to perform in-cylinder braking operation. The exhaust gas release valve controls the air volume, which is then switched to the intake throttle valve. This allows the intake throttle valve to control the intercooler pressure in a closed loop to control the braking power, thereby adjusting the braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

2. The method according to claim 1, characterized in that, The engine operating condition information includes engine throttle opening information, gear information, engine speed information, and brake switch status information; Accordingly, the step of determining the operating condition based on the engine operating condition information, and obtaining the intercooler pressure value when the current operating condition is detected to be braking, includes: Based on the engine throttle opening information, determine whether the throttle opening is 0; based on the gear information, determine whether the gear is in gear; based on the engine speed information, determine whether the engine speed is greater than a preset speed threshold; based on the brake switch status information, determine whether the in-cylinder brake switch is open. When the throttle opening is 0, the gear is in gear, the engine speed is greater than the preset speed threshold, and the in-cylinder brake switch is on, the intercooler pressure value is obtained.

3. The method according to claim 1, characterized in that, Also includes: When the intercooler pressure value is detected to be less than the first intake pressure value, the cylinder braking operation is performed according to the first pre-stored universal characteristic curve, so as to adjust the braking power by controlling the opening of the exhaust gas release valve.

4. The method according to claim 1, characterized in that, Also includes: When the intercooler pressure value is detected to be equal to the first intake pressure value, the cylinder braking operation is performed according to the second pre-stored universal characteristic curve, so as to achieve the braking power by controlling the amount of gas only by controlling the exhaust gas release valve.

5. The method according to any one of claims 1 to 4, characterized in that, Also includes: The vehicle controller sends a warning command to the instrument panel, so that the instrument panel issues a warning message based on the warning command.

6. An engine protection system under braking conditions, used to execute the method according to any one of claims 1 to 5, characterized in that, include: Vehicle controller, exhaust gas release valve, intake throttle valve, and in-cylinder pressure sensor; The vehicle controller is connected to the exhaust gas release valve, intake throttle valve and cylinder pressure sensor via data connection, and the vehicle controller is connected to the vehicle control unit via the vehicle bus. The vehicle controller is used to acquire engine operating condition information; to determine the operating condition based on the engine operating condition information; when the current operating condition is detected to be braking, to acquire the intercooler pressure value; and to determine the first intake pressure value based on the engine operating condition information, a preset first required braking power, and a second pre-stored universal characteristic curve; when the intercooler pressure value is detected to be greater than the first intake pressure value, to perform in-cylinder braking operation according to the third pre-stored universal characteristic curve, so as to achieve the adjustment of braking power by controlling the air volume only by controlling the opening of the intake throttle valve.

7. The system according to claim 6, characterized in that, Also includes: meter; The instrument is connected to the vehicle controller for data transmission. The instrument is used to receive warning commands sent by the vehicle controller and to send warning information according to the warning commands.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by the vehicle controller, are used to implement the method as described in any one of claims 1 to 5.

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