Gearbox protection method and device and computer readable storage medium

Abstract

According to the gearbox protection method and device and the computer readable storage medium, in the operation process of an oil pump, the motor state parameter value of an oil pump motor during operation of the oil pump in the gearbox is monitored, and the air suction condition of the oil pump is accurately recognized and judged according to the change of the motor state parameter value. After the air suction state of the oil pump is determined, the parameter value of the vehicle power part associated with the oil pump is adjusted according to the subsequent processing strategy corresponding to the air suction state, the overheating working condition caused by air suction of the oil pump is effectively avoided, and therefore the purpose of preventing a gearbox from being damaged due to air suction of the oil pump is practically achieved; and stable, efficient and safe operation of a vehicle power system is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of gearboxes, and particularly to a gearbox protection method, device and computer-readable storage medium. Background Art

[0002] When the vehicle is in a driving state, the oil in the gearbox is in a dynamic circulation process. If the oil fails to completely cover the oil inlet of the oil pump oil circuit, air will enter the oil pump oil circuit, which will cause the failure of the oil pump's oil suction function. This situation will cause the components in the gearbox to be in a high-temperature environment due to lack of sufficient lubrication and heat dissipation, and it is very easy to cause serious consequences such as overheating and burning of parts and loss of driving ability of the actuating elements.

[0003] Therefore, how to provide a method to prevent the gearbox from being damaged due to oil pump cavitation is a technical problem that those skilled in the art need to solve urgently at present. Summary of the Invention

[0004] To overcome the problems in the related art, this specification provides a gearbox protection method, device and computer-readable storage medium.

[0005] According to the first aspect of the embodiments of this specification, a gearbox protection method is provided, and the method includes:

[0006] Monitoring the motor state parameter values of the oil pump motor when the oil pump in the gearbox is running;

[0007] Determining whether the oil pump is in a cavitation state according to the change of the motor state parameter values;

[0008] When the oil pump is in a cavitation state, adjusting the parameter values of the vehicle power components related to the oil pump according to the post-processing strategy corresponding to the cavitation state.

[0009] According to a gearbox protection method provided by this application, the motor state parameter values include the actual speed and actual current of the oil pump motor,

[0010] The determining whether the oil pump is in a cavitation state according to the change of the motor state parameter values includes:

[0011] Determining that the oil pump is in a cavitation state when the difference between the actual speed and the set target speed is less than the first speed difference threshold value and the actual current is less than the set target current.

[0012] According to a gearbox protection method provided by this application, the cavitation state includes a long-term cavitation state,

[0013] The method further includes:

[0014] Record a first duration during which the actual current is less than the target current;

[0015] When the first duration is greater than a first time threshold value, determine that the oil pump is in a long-term air suction state.

[0016] According to a transmission protection method provided by the present application, the air suction state includes an intermittent air suction state.

[0017] The method further includes:

[0018] When the difference between the actual speed and the set target speed is less than a first speed difference threshold value, and when the first duration is less than or equal to the first time threshold value, continuously monitor the change of the motor state parameter value;

[0019] If the change of the continuously monitored motor state parameter value meets the set overspeed condition, record a second duration during which the oil pump continuously meets the overspeed condition;

[0020] If the second duration is greater than a second time threshold value, record the number of times of the speed change of the oil pump, where the speed change is the change of the actual speed from being consistent with the target speed to exceeding the target speed;

[0021] If the accumulated number of times reaches the number threshold value, determine that the oil pump is in an intermittent air suction state.

[0022] According to a transmission protection method provided by the present application, the method further includes:

[0023] When the difference between the actual speed and the target speed is less than the first speed difference threshold value, set the ideal speed flag of the oil pump to a second flag, and initially set the overspeed flag of the oil pump to a first flag;

[0024] When the change of the motor state parameter value meets the set overspeed condition, and the second duration during which the oil pump continuously meets the overspeed condition is greater than the second time threshold value, set the overspeed flag of the oil pump to the second flag;

[0025] The recording of the number of times of the speed change of the oil pump includes:

[0026] When the ideal speed flag and the overspeed flag of the oil pump meet the flag indication condition, record the number of times of the speed change of the oil pump once;

[0027] Wherein, the flag indication condition includes: the ideal speed flag of the oil pump is set to the second flag, and the overspeed flag is set to the second flag.

[0028] According to a transmission protection method provided by the present application, the overspeed condition includes:

[0029] The actual rotational speed is greater than or equal to the sum of the set target rotational speed and the second speed difference threshold value, where the second speed difference threshold value is greater than or equal to the first speed difference threshold value;

[0030] and / or

[0031] The actual current is less than the difference between the set target current and the current difference threshold value.

[0032] According to a transmission protection method provided by the present application, the method includes: when the oil pump is in a cavitation state, outputting information indicating an abnormality caused by the cavitation of the oil pump;

[0033] and / or

[0034] The post - processing strategy includes opening the solenoid valve of the clutch in the transmission.

[0035] According to a transmission protection method provided by the present application, when the oil pump is in a cavitation state, adjusting the parameter values of the vehicle power components related to the oil pump according to the post - processing strategy corresponding to the cavitation state, includes:

[0036] When the oil pump is in a cavitation state, reducing the power of the first motor and the second motor of the transmission. The first motor is used to transmit the torque of the engine to the wheel end through the clutch to drive the vehicle, and the second motor is used to drive the vehicle and recover energy during braking.

[0037] According to a transmission protection method provided by the present application, the method further includes:

[0038] Controlling the power of the first motor to decrease as the temperature of the first motor increases, and controlling the power of the second motor to decrease as the temperature of the second motor increases until the vehicle stops driving.

[0039] According to a transmission protection method provided by the present application, the method further includes:

[0040] Reducing the power of the first motor and the second motor in the transmission, includes:

[0041] Reducing the power of the first motor;

[0042] When the reduced power reaches a threshold value, reducing the power of the second motor.

[0043] According to a transmission protection method provided by the present application, the method further includes:

[0044] When the oil pump is in an intermittent cavitation state, reducing the torque change rate of the second motor.

[0045] The present application also provides a transmission protection device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the transmission protection method as described in any one of the above.

[0046] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the transmission protection method as described in any one of the above.

[0047] In the transmission protection method, device, and computer-readable storage medium according to the embodiments of this specification, during the operation of the oil pump, the motor state parameter values of the oil pump motor during the operation of the oil pump in the transmission are monitored. According to the changes in the motor state parameter values, the air suction condition of the oil pump is accurately identified and determined. After determining the air suction state of the oil pump, the parameter values of the vehicle power components associated with the oil pump are adjusted according to the subsequent processing strategy corresponding to the air suction state, effectively avoiding the overheating working condition caused by the air suction of the oil pump, thereby effectively achieving the goal of preventing the transmission from being damaged due to the air suction of the oil pump and ensuring the stable, efficient, and safe operation of the vehicle power system.

[0048] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with this specification, and are used together with the specification to explain the principles of this specification.

[0050] Figure 1 is a flowchart showing the transmission protection method according to an exemplary embodiment of this specification;

[0051] Figure 2 is another flowchart showing the transmission protection method according to an exemplary embodiment of this specification;

[0052] Figure 3 is a schematic diagram of a transmission protection device according to an exemplary embodiment of this specification;

[0053] Figure 4 is a schematic block diagram of a transmission protection device according to an exemplary embodiment of this specification. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] Here, the technical solutions in the embodiments (or "embodiment modes") of the present application will be clearly and completely described in conjunction with the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0055] If there are terms related to directional indication or positional relationship in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), then such terms are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the drawings); if the specific posture changes, then the directional indication or positional relationship also changes accordingly. In addition, the terms "first", "second", etc. involved in the embodiments of the present application are only for the purpose of convenient description, and cannot be understood as indicating or implying relative importance.

[0056] The present application provides a gearbox protection method, device and computer-readable storage medium. The following will describe the present application in detail with reference to the drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0057] An electronic oil pump is equipped inside the gearbox. When the vehicle is in a driving state, the oil fluid inside the gearbox is in a dynamic circulation process. If the oil fluid fails to completely cover the oil inlet of the oil pump oil circuit, air will enter the oil pump oil circuit, thereby causing the failure of the oil pump's oil suction function. This situation will cause the components inside the gearbox to be in a high-temperature environment due to lack of sufficient lubrication and heat dissipation, and it is extremely easy to cause serious consequences such as overheating and burning of parts and loss of driving ability of the actuating elements.

[0058] Secondly, for the actuating elements in the gearbox, such as clutch solenoid valves, etc., their operation depends on the oil fluid pressure to achieve precise action control. Without sufficient oil fluid pressure, the actuating elements cannot drive normally, which will cause the functions such as gear shifting of the gearbox to be unable to proceed normally, and the operation of the entire gearbox will be in chaos. In the long run, the gearbox will inevitably suffer serious damage. Therefore, the core purpose of solving the problem of oil pump air suction is to avoid damage to the gearbox and ensure the normal operation of the vehicle transmission system.

[0059] To solve the above technical problems, this specification provides a gearbox protection method.

[0060] It aims to accurately identify and determine the oil pump air suction condition, timely implement corresponding subsequent treatment measures, effectively avoid the overheating working condition caused by oil pump air suction, and thus effectively achieve the goal of preventing the gearbox from being damaged due to oil pump air suction.

[0061] The present application provides an embodiment of a gearbox protection method, referring to Figure 1 , Figure 1 is a flowchart of a gearbox protection method provided by an embodiment of this specification, including the following steps:

[0062] Step 110, monitor the motor state parameter values of the oil pump motor when the oil pump in the gearbox is running.

[0063] The motor state parameter values include the actual speed and actual current of the oil pump motor. By monitoring the motor state parameter values of the oil pump motor in real time when the oil pump in the gearbox is running, it is possible to accurately judge whether the oil pump is in an air suction state based on the dynamic changes of the motor state parameter values.

[0064] When the oil pump is working properly, the motor drives the oil pump to rotate, sucks the oil fluid from the inlet and discharges it through the outlet. In this process, the motor needs to overcome the resistance of the oil fluid to maintain a certain speed.

[0065] Under normal circumstances, the actual speed usually needs to be stably maintained within the target speed range. This can ensure that the oil pump transports the oil fluid stably according to the design requirements and meets the oil fluid requirements of components such as the transmission. At the same time, since there is a certain corresponding relationship between the speed and current of the oil pump motor when it is working properly. It can be understood that when the oil pump is sucking oil normally, the motor driving the oil pump overcomes a certain resistance (mainly the pressure of the oil fluid and the viscous resistance of the oil fluid, etc.) to reach the target speed, and at this time the motor current is at an ideal value matching this working state. This means that when the actual speed of the oil pump motor reaches the target speed, the current of the oil pump motor is theoretically near the target current.

[0066] However, when the oil pump has an air suction phenomenon, the pressure change inside the oil pump will affect the load of the motor. It can be understood that if the oil pump is air suction, it means that the oil fluid sucked by the oil pump decreases, the load of the motor becomes smaller, and the speed may change.

[0067] Therefore, by monitoring the motor state parameters of the oil pump motor in real time when the oil pump in the gearbox is running, the working state of the oil pump is identified through the changes in the actual speed and actual current of the oil pump motor. After it is determined that the oil pump is in an air suction state, the parameter values of the vehicle power components associated with the oil pump are adjusted according to the specific post-processing strategy corresponding to the air suction state. In this way, a series of serious problems caused by the air suction of the oil pump can be effectively prevented, the stable, efficient and safe operation of the vehicle power system is guaranteed, the probability of faults is reduced, and the service life of the gearbox equipment is extended.

[0068] Step 120, determine whether the oil pump is in an air suction state according to the changes in the motor state parameter values.

[0069] When the oil pump is working properly, the actual speed and actual current of its motor will be within a relatively stable numerical range that conforms to the normal working logic. However, when air starts to be sucked into the inlet of the oil pump, that is, an air suction phenomenon occurs, the load of the motor will change significantly.

[0070] In some embodiments, determining whether the oil pump is in an air suction state according to the change of the motor state parameter value includes:

[0071] Step 121, when the difference between the actual speed and the set target speed is less than the first speed difference threshold value and the actual current is less than the set target current, it is determined that the oil pump is in an air suction state.

[0072] Under normal circumstances, the difference between the actual speed and the set target speed will become smaller. If this difference is less than the first speed difference threshold value, and at the same time, because of air suction, the motor load is reduced, and the actual current will also be less than the set target current. When these two conditions are met simultaneously, it can be preliminarily determined that the oil pump is in an air suction state.

[0073] Through the above embodiments, it is possible to accurately judge whether the oil pump is in an air suction state. This method provides an efficient and reliable basis for timely detecting the air suction of the oil pump, which is beneficial to taking countermeasures in advance to ensure the stable operation of the vehicle transmission system.

[0074] The air suction state of the oil pump includes a long-term air suction state and an intermittent air suction state. In the case where the oil pump is set with a fixed target speed, when the actual speed is consistent with the established target speed, but the current of the oil pump motor is lower than the expected ideal value, this phenomenon indicates that the oil pump has a long-term air suction condition; and if the actual speed intermittently exceeds the target speed, it means that the oil pump has encountered an intermittent air suction problem. This method of judging the type of air suction of the oil pump based on the changes of speed and current parameters provides an effective basis for accurately identifying the abnormal operation of the oil pump, which helps to adopt different control strategies for different types of air suction during the vehicle operation to reduce the impact on vehicle performance.

[0075] In some embodiments, the identification process for the long-term air suction state is as follows:

[0076] In the case of long-term air suction, a large amount of air enters the oil pump. Due to the compressibility of air and the low viscous resistance, the motor load is significantly reduced. This enables the motor to reach the target speed while not requiring as much current as in normal oil suction to maintain operation, so the actual current will be lower than the target current. When the actual current continuously remains lower than the target current, it is confirmed that the oil pump has a long-term air suction problem.

[0077] As an example, the identification process for the long-term air suction state includes:

[0078] Step a11, when the difference between the actual speed and the set target speed is less than the first speed difference threshold value and the actual current is less than the set target current; record the first duration during which the actual current is less than the target current.

[0079] Step a12: When the first duration is greater than the first time threshold, it is determined that the oil pump is in a long-term air suction state.

[0080] The first speed difference threshold described in this article is a pre-set speed difference standard. It is used to measure whether the deviation between the actual speed of the oil pump motor and the set target speed is within an acceptable range, so as to assist in judging the working state of the oil pump.

[0081] Under normal working conditions, the actual speed of the oil pump motor is stable near the target speed, and there will be a small reasonable difference between the two, that is, the first speed difference threshold. This first speed difference threshold is caused by factors such as minor changes in vehicle working conditions, normal fluctuations in the system, or measurement errors. When the difference between the actual speed and the target speed is less than the first speed difference threshold, it indicates that the motor speed is close to the target speed.

[0082] The first time threshold described in this article is a standard of time length. It is used to determine whether the abnormal situation that the actual current of the oil pump motor is less than the target current lasts long enough when the actual speed of the oil pump motor is consistent with the set target speed, so as to judge whether the oil pump is in a long-term air suction state.

[0083] When the actual current is less than the target current, the timer Timer1 is activated to start recording this duration, and the first duration is obtained. If the first duration exceeds the first time threshold, it is definitely considered that the oil pump has a long-term air suction, rather than a short-term current abnormality. This helps to avoid misjudgment caused by instantaneous interference or short-term working condition changes and improve the accuracy of judging the long-term air suction state of the oil pump.

[0084] In some embodiments, the identification process for the intermittent air suction state is as follows:

[0085] For intermittent air suction, air enters the oil pump intermittently, which causes the load of the oil pump to decrease intermittently. When air enters, the load of the motor drops instantaneously, and the speed will intermittently exceed the target speed because the motor is easier to accelerate when overcoming less resistance. This intermittent fluctuation of the speed is the key feature for judging intermittent air suction, indicating that the oil pump has an intermittent air suction problem.

[0086] As an example, the identification process of the intermittent air suction state includes:

[0087] Step b11: When the difference between the actual speed and the set target speed is less than the first speed difference threshold and the first duration is less than or equal to the first time threshold, continuously monitor the change of the motor state parameter value;

[0088] Step b12, if the change in the continuously monitored motor state parameter value meets the set overspeed condition, record the second duration for which the oil pump continuously meets the overspeed condition;

[0089] Step b13, if the second duration is greater than the second time threshold, record the number of times of the rotational speed change of the oil pump, where the rotational speed change is the change of the actual rotational speed from being consistent with the target rotational speed to exceeding the target rotational speed;

[0090] Step b14, if the accumulated number of times reaches the number threshold, determine that the oil pump is in an intermittent air suction state.

[0091] When the first duration during which the actual current is less than the target current lasts for less than or equal to the first time threshold, it indicates that although the current is small at present, the duration has not reached the level of being recognized as long-term air suction. It may be caused by only short-term fluctuations or other temporary factors. Continue to monitor the motor state parameter values (including the actual rotational speed, actual current, etc.) so as to further analyze the working state of the oil pump according to the dynamic changes of the parameters in the future.

[0092] As described above, the intermittent fluctuation of the rotational speed is the key feature for judging intermittent air suction. When the actual rotational speed of the oil pump motor has a specific rotational speed change, it means that the oil pump has an intermittent air suction problem. This specific rotational speed change refers to the change process of the actual rotational speed from being consistent with the target rotational speed to the actual rotational speed exceeding the target rotational speed, or then continuing to change back to the state where the actual rotational speed is consistent with the target rotational speed.

[0093] The overspeed condition here is a pre-set standard for judging whether the oil pump has an abnormal rotational speed situation. For example, if the change in the motor state parameter value is used to judge whether the oil pump has an abnormal rotational speed situation, then set the overspeed condition related to the motor state parameter value.

[0094] As an example, this overspeed condition can specifically be that the actual rotational speed is greater than or equal to the sum of the set target rotational speed and the second speed difference threshold.

[0095] Among them, the second speed difference threshold is the speed difference standard for judging the overspeed state of the oil pump motor. It is a value added on the basis of the target rotational speed and is used to measure whether the actual rotational speed of the oil pump motor exceeds the normal and reasonable range.

[0096] It should be noted that the second speed difference threshold is greater than or equal to the first speed difference threshold. The first speed difference threshold is used to judge whether the actual speed is consistent with the target speed, and the second speed difference threshold is used to judge whether the actual rotational speed is on the high side relative to the target rotational speed. Therefore, the second speed difference threshold is set to be greater than or equal to the first speed difference threshold. For example, the first speed difference threshold is 20 revolutions per minute and the second speed difference threshold is 60 revolutions per minute.

[0097] As another example, this overspeed condition may specifically be that the actual current is less than the difference between the set target current and the current difference threshold value. The current difference threshold value is a difference standard used to determine whether the actual current of the oil pump motor is too small. When an abnormal situation occurs, such as cavitation, the motor load decreases and the actual current will drop. By comparing the actual current with the result of subtracting this current difference threshold value from the set target current, it is determined whether the current is in an abnormally low level state. For example, when the actual current is less than the difference between the set target current and the current difference threshold value, it indicates that the degree of current drop has reached an abnormal level, because cavitation has occurred in the oil pump.

[0098] When it is continuously monitored and found that the change in the motor state parameter value satisfies this overspeed condition, the timer Timer2 is activated to start recording the time for which the oil pump has been in this overspeed state, that is, the second duration. Recording the second duration is for further determining whether this overspeed situation occurs occasionally or lasts for a long time subsequently, so as to assist in judging whether there is an intermittent cavitation problem with the oil pump.

[0099] When the second duration exceeds the second time threshold value, it means that this overspeed situation has lasted for a relatively long time and is not an instantaneous abnormality. When the above-mentioned actual rotational speed changes from the state of being originally consistent with the target rotational speed to exceeding the target rotational speed, the number of such rotational speed changes needs to be recorded once. This specific rotational speed change is one of the key features for judging intermittent cavitation, because during intermittent cavitation, air intermittently enters the oil pump, causing the load of the oil pump to decrease intermittently, and thus resulting in the rotational speed intermittently changing from the normal state to exceeding the target rotational speed. By recording such a number of times, the frequency of this abnormal change can be statistically counted.

[0100] When the number of times of this change accumulates to the number threshold value, it means that this abnormal rotational speed change occurs relatively frequently, which conforms to the characteristic performance of intermittent cavitation. Therefore, based on such a logical judgment, it is determined that the oil pump is in an intermittent cavitation state at this time.

[0101] In some other embodiments, the fluctuation change of the oil pump is determined by the change of a flag representing speed.

[0102] Referring to Figure 2 , the identification process of the long-term cavitation state includes:

[0103] Maintain the target rotational speed of the oil pump motor. This target rotational speed is generally calculated based on the temperature of the motor and the clutch to obtain the flow rate demand, and then the rotational speed of the oil pump is calculated based on the flow rate demand.

[0104] If the difference between the actual speed and the target speed is less than the first speed difference threshold, set the ideal speed flag of the oil pump to the second flag, that is, Flag1 = 1.

[0105] On this basis, when the actual current of the oil pump motor is less than the target current, activate the timer Timer1 and record the first duration. When the first duration of the timer Timer1 is greater than the first time threshold, set the ideal speed flag of the oil pump to the first flag, that is, Flag1 = 0. At this time, the overspeed flag of the oil pump is initially set to the first flag, that is, Flag2 = 0.

[0106] Finally, when the ideal speed flags of the oil pump are Flag1 = 0 and Flag2 = 0, it is determined that the oil pump has a long - time air - sucking problem.

[0107] Refer to Figure 2 , the identification process of the intermittent air - sucking state includes:

[0108] If the difference between the actual speed and the target speed is less than the first speed difference threshold, set the ideal speed flag of the oil pump to the second flag, that is, Flag1 = 1.

[0109] If the change of the motor state parameter value meets the set overspeed condition (for example, the actual speed is greater than or equal to the sum of the set target speed and the second speed difference threshold), activate the timer Timer2 and record the second duration.

[0110] When the second duration of the timer Timer2 is greater than the second time threshold, set the overspeed flag of the oil pump to the second flag, that is, Flag2 = 1.

[0111] At this time, when the ideal speed flag and the overspeed flag of the oil pump meet the flag indication conditions, record the number of times of the speed change of the oil pump once; among them, the flag indication conditions include: the ideal speed flag of the oil pump is set to the second flag, and the overspeed flag is set to the second flag.

[0112] That is, when Flag1 = 1 and Flag2 = 1, record the number of times of the speed change of the oil pump once, and the cumulative activation times N1 = N1 + 1.

[0113] Finally, when the cumulative number N1 > the number threshold, it is determined that the oil pump has an intermittent air - sucking problem. The two flags of the ideal speed flag and the overspeed flag indicate that there is a short - term equal speed and then a high speed. When the number of occurrences of this situation exceeds the number threshold, it is considered that an intermittent air - sucking occurs once.

[0114] Through the recognition steps and corresponding threshold setting of the above embodiments, by dynamically monitoring and analyzing the state parameters such as the rotation speed and current of the oil pump motor, accurately judge whether the oil pump is in a long-term air suction state or an intermittent air suction state according to certain logic and standards, providing an accurate basis for subsequent system adjustment.

[0115] Step 130, when the oil pump is in an air suction state, adjust the parameter values of the vehicle power components related to the oil pump according to the post-treatment strategy corresponding to the air suction state.

[0116] After accurately detecting the air suction condition of the oil pump, timely implement the corresponding subsequent treatment measures, effectively avoiding the overheating working condition caused by the air suction of the oil pump, and thus protecting the transmission.

[0117] As an example, the subsequent treatment measures include but are not limited to at least one of reporting a transmission fault and instrument display, controlling the opening of the clutch solenoid valve, limiting the motor power in the transmission, and restricting the change of motor torque.

[0118] Specifically, for the long-term air suction state of the oil pump, the corresponding subsequent treatment measures include:

[0119] First, when the oil pump is in an air suction state, output information indicating the abnormality caused by the air suction of the oil pump. Since the vehicle cannot continue to drive during long-term air suction and needs to stop as soon as possible, the abnormal information can be but is not limited to reporting a transmission fault and displaying the information of "low transmission fluid and pull over" on the instrument panel.

[0120] Second, open the solenoid valve of the clutch in the transmission.

[0121] The clutch is a key component in the vehicle transmission system, and its main function is to cut off or connect the power transmission between the engine and the transmission.

[0122] The first motor of the transmission is connected to the engine. When the engine is running, the torque of the engine is transmitted to the wheel end through the clutch to drive the vehicle. The second motor is used to drive the vehicle and recover energy during braking. When the vehicle needs power drive, the second motor serves as a power source, converting electrical energy into mechanical energy and driving the vehicle through the transmission system. When the vehicle brakes, the rotation of the wheels drives the second motor to reverse, converting the kinetic energy of the vehicle into electrical energy and recovering it into the battery.

[0123] When the clutch is opened, the vehicle enters the EV mode (pure electric mode) and the series driving mode. In the EV mode, the vehicle relies on the first motor and the second motor to provide power, and the engine does not directly participate in driving the vehicle. When the clutch is opened, the connection between the engine and the transmission system is switched, and the power of the first motor and the engine will not be transmitted to the wheel end, and the vehicle is driven by the motor.

[0124] When the clutch is engaged and the vehicle is in the parallel driving mode, the power of the engine and the power of the motor participate in driving the wheels simultaneously. The engine generates positive torque, and a part of this torque is used to overcome the power generation torque of the first motor (because the first motor will generate a certain resistance to the engine when generating electricity), and the remaining torque will be transmitted to the wheel end through the transmission system to drive the vehicle to travel.

[0125] Under normal circumstances, the separation and engagement of the clutch are controlled by a hydraulic system. When the clutch needs to be separated (opened) or engaged, hydraulic oil is pumped into or discharged from the hydraulic chamber of the clutch to push components such as pistons to achieve the clutch action. If the vehicle enters a mode where the clutch is not required to participate in power transmission (such as EV mode and series driving), and the clutch is kept open, there is no need to frequently control the separation and engagement of the clutch, thereby reducing the demand for hydraulic oil, and the working load of the oil pump is correspondingly reduced. The reduced load helps to reduce the risk of cavitation, thereby protecting the transmission. At the same time,

[0126] The reduced demand for hydraulic oil also correspondingly reduces the rotational speed demand of the oil pump, which means that the processes generating heat such as friction inside the oil pump and agitation of the oil fluid will also weaken, thereby reducing the thermal condition of the entire system.

[0127] Moreover, when the clutch is open, the driving plate and the driven plate of the clutch are separated, without mutual friction and without generating heat due to friction, which also reduces the rotational speed demand of the oil pump, achieving the purpose of avoiding the generation of overheating conditions and protecting the transmission.

[0128] Thirdly, when the oil pump is in a cavitation state, reduce the power of the first motor and the second motor of the transmission.

[0129] It can be understood that when the oil pump has a cavitation problem, if the power of the first motor and the second motor is too high, it will cause the working states of other components to be chaotic. Therefore, to avoid the power system of the vehicle from being disordered due to the cavitation problem of the oil pump, by limiting the motor power to prevent the motor from outputting excessive power, the power system of the vehicle is in a relatively stable state to protect the various components of the vehicle and prevent component damage or abnormal operation caused by excessive power.

[0130] Specifically, set an initial limit target, and reduce the power of the first motor and the second motor to the initial limit target. For example, the initial limit target is 70% of the original calibration target. Among them, if the temperatures of the first motor and the second motor gradually increase, control the power of the first motor to decrease as the temperature of the first motor increases, and control the power of the second motor to decrease as the temperature of the second motor increases until the vehicle stops driving. This control strategy of motor power changing with temperature can effectively prevent the motor from being damaged by overheating.

[0131] In some examples, reducing the power of the first motor and the second motor in the gearbox includes:

[0132] Reducing the power of the first motor;

[0133] When the reduced power reaches a threshold value, reducing the power of the second motor.

[0134] It can be understood that during the process of continuous temperature rise, the power of the first motor is preferentially reduced. When the first motor drops to the threshold value (such as 10% of the original calibrated target), the power of the second motor begins to be reduced. On the basis of effectively preventing the motor from overheating and damage, the motor power is reasonably distributed. The vehicle power performance and system safety are balanced, the service life of the motor and related components is extended, and the reliability and stability of the overall vehicle operation are improved.

[0135] Specifically, for the subsequent treatment measures corresponding to the oil pump being in an intermittent air suction state, including:

[0136] First, when the oil pump is in an air suction state, output information indicating an abnormality caused by the air suction of the oil pump. During intermittent air suction, the vehicle needs to travel with limited power and avoid loosening of the vehicle to cause a decrease in the oil intake. The abnormal information can be but is not limited to reporting a transmission fault and displaying the information of "low transmission fluid" on the instrument panel.

[0137] Second, the clutch solenoid valve is opened. Similar to the specific embodiment where the oil pump is in a long-term air suction state, it will not be elaborated here.

[0138] Third, when the oil pump is in an air suction state, reduce the power of the first motor and the second motor in the gearbox. Similar to the specific embodiment where the oil pump is in a long-term air suction state, it will not be elaborated here. It should be noted that compared with the problem of long-term air suction of the oil pump, the above three treatment measures for intermittent air suction are relatively mild. In this state, the vehicle can continue to travel. As an example, the amplitude of reducing the power of the first motor and the second motor in the gearbox when the oil pump is in an intermittent air suction state is less than or equal to the amplitude of reducing the power of the first motor and the second motor in the gearbox when the oil pump is in a long-term air suction state.

[0139] Fourth, when the oil pump is in an intermittent air suction state, reduce the torque change rate of the second motor.

[0140] The torque change rate refers to the speed of change of the motor torque. When the clutch solenoid valve is opened, the first motor will not cause the vehicle acceleration to change. At this time, the torque change rate of the second motor is limited to avoid the vehicle from jerking due to unstable power, ensuring the smoothness and safety of the vehicle driving. Further avoid the vehicle jerking increasing the oil intake of the oil pump, making the working environment of the oil pump relatively stable and alleviating the intermittent air suction problem of the oil pump.

[0141] Through the above embodiments, when the oil pump is in a cavitation state, the corresponding post-processing strategy is implemented in a timely manner to adjust the parameter values of the vehicle power components related to the oil pump, effectively avoiding the overheating working condition caused by the cavitation of the oil pump, and thus protecting the gearbox.

[0142] The present application provides a gearbox protection method, device and computer-readable storage medium. During the operation of the oil pump, the motor state parameter values of the oil pump motor during the operation of the oil pump in the gearbox are monitored. According to the change of the motor state parameter values, the cavitation condition of the oil pump is accurately identified and determined. After determining the cavitation state of the oil pump, the parameter values of the vehicle power components related to the oil pump are adjusted according to the subsequent processing strategy corresponding to the cavitation state, effectively avoiding the overheating working condition caused by the cavitation of the oil pump, thereby effectively achieving the goal of preventing the gearbox from being damaged due to the cavitation of the oil pump, and ensuring the stable, efficient and safe operation of the vehicle power system.

[0143] Based on the same application concept as the above method, an embodiment of the present application also proposes a gearbox protection device, as Figure 3 shown.

[0144] The device includes:

[0145] A state monitoring module 302, configured to monitor the motor state parameter values of the oil pump motor during the operation of the oil pump in the gearbox;

[0146] A state identification module 304, configured to determine whether the oil pump is in a cavitation state according to the change of the motor state parameter values;

[0147] A post-processing module 306, configured to adjust the parameter values of the vehicle power components related to the oil pump according to the post-processing strategy corresponding to the cavitation state when the oil pump is in a cavitation state.

[0148] The implementation processes of the functions and roles of each module / sub-module / unit in the above device are specifically described in the implementation processes of the corresponding steps in the above method, and the same technical effects can be achieved, which will not be elaborated here.

[0149] Figure 4 Illustrates a schematic physical structure diagram of a gearbox protection device, as Figure 4As shown, the transmission protection device may include: a processor 810, a communications interface 820, a memory 830, and a communication bus 840. Among them, the processor 810, the communications interface 820, and the memory 830 complete mutual communication through the communication bus 840. The processor 810 may call the logical instructions in the memory 830 to execute the transmission protection method.

[0150] In addition, when the logical instructions in the above-mentioned memory 830 are implemented in the form of software functional units and sold or used as independent products, they may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, may be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0151] On the other hand, this application also provides a computer program product. The computer program product includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the transmission protection method provided by the above-mentioned various methods.

[0152] On another aspect, this application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the transmission protection method provided by the above-mentioned various methods.

[0153] It should be noted that the technical solutions or technical features described in the above embodiments may be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A gearbox protection method, characterized in that: The method comprises: Monitoring the motor state parameter value of the oil pump motor when the oil pump in the gearbox is running; Determining whether the oil pump is in an empty state according to a change in the motor state parameter value; When the oil pump is in an empty state, parameter values ​​of vehicle power components related to the oil pump are adjusted according to a post-processing strategy corresponding to the empty state.

2. The gearbox protection method according to claim 1, characterized in that: The motor state parameter value includes the actual speed and actual current of the oil pump motor. The step of determining whether the oil pump is in an empty state according to the change of the motor state parameter value comprises: When the difference between the actual speed and the set target speed is smaller than a first speed difference threshold value and the actual current is smaller than the set target current, it is determined that the oil pump is in an air suction state.

3. The gearbox protection method according to claim 2, characterized in that: The vacuum state includes a long-term vacuum state. The method further comprises: Recording a first time duration during which the actual current is less than the target current; When the first time length is greater than a first time threshold value, it is determined that the oil pump is in a long-term empty suction state.

4. The gearbox protection method according to claim 2, characterized in that: The vacuum state includes an intermittent vacuum state. The method further comprises: When the difference between the actual speed and the set target speed is less than a first speed difference threshold, and when the first time duration is less than or equal to a first time threshold, continuously monitoring the change of the motor state parameter value; If the continuously monitored change in the motor state parameter value meets the set overspeed condition, record the second time duration that the oil pump continues to meet the overspeed condition; If the second time length is greater than the second time threshold, the number of times the speed of the oil pump changes is recorded, wherein the speed change is a change of the actual speed from being consistent with the target speed to exceeding the target speed; If the accumulated number of times reaches the number threshold, it is determined that the oil pump is in an intermittent air suction state.

5. The gearbox protection method according to claim 2, characterized in that: The method further comprises: When the difference between the actual speed and the target speed is less than the first speed difference threshold, the ideal speed mark of the oil pump is set to the second mark, and the overspeed mark of the oil pump is initially set to the first mark; When the change of the motor state parameter value satisfies the set overspeed condition, and the second time length during which the oil pump continuously satisfies the overspeed condition is greater than the second time threshold value, setting the overspeed flag of the oil pump to the second flag; The recording of the number of times the speed of the oil pump changes once includes: When the ideal speed mark and the overspeed mark of the oil pump meet the mark indication conditions, the number of times the speed of the oil pump changes is recorded once; Wherein, the flag indication condition includes: the ideal speed flag of the oil pump is set to the second flag, and the overspeed flag is set to the second flag.

6. The gearbox protection method according to any one of claims 4 to 5, characterized in that: The overspeed conditions include: The actual speed is greater than or equal to the sum of the set target speed and a second speed difference threshold value, wherein the second speed difference threshold value is greater than or equal to the first speed difference threshold value; and / or The actual current is smaller than the difference between the set target current and the current difference threshold value.

7. The gearbox protection method according to claim 1, characterized in that: The method comprises: when the oil pump is in an evacuation state, outputting information indicating an abnormality caused by the evacuation of the oil pump; and / or The aftertreatment strategy includes opening a solenoid valve of a clutch in the transmission.

8. The gearbox protection method according to claim 1, characterized in that: When the oil pump is in an empty state, adjusting the parameter values ​​of the vehicle power components related to the oil pump according to the post-processing strategy corresponding to the empty state includes: When the oil pump is in an empty state, the power of the first motor and the second motor of the gearbox is reduced. The first motor is used to transmit the torque of the engine to the wheel end through the clutch to drive the vehicle, and the second motor is used to drive the vehicle and recover energy during braking.

9. The gearbox protection method according to claim 8, characterized in that: The method further comprises: The power of the first motor is controlled to decrease as the temperature of the first motor increases, and the power of the second motor is controlled to decrease as the temperature of the second motor increases until the vehicle stops running.

10. The gearbox protection method according to claim 8, characterized in that: The method further comprises: The step of reducing the power of the first motor and the second motor in the gearbox comprises: reducing the power of the first motor; When the reduced power reaches a threshold, the power of the second motor is reduced.

11. The gearbox protection method according to claim 8, characterized in that: The method further comprises: When the oil pump is in an intermittent air suction state, the torque change rate of the second motor is reduced.

12. A gearbox protection device, characterized in that: The invention comprises a memory, a processor and a gearbox protection program stored in the memory and executable on the processor, wherein the processor implements the gearbox protection method according to any one of claims 1 to 11 when executing the gearbox protection program.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a gearbox protection program, which, when executed, implements the gearbox protection method according to any one of claims 1 to 11.

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