Clutch pre-filling oil control method and device

Abstract

The present invention relates to the field of vehicle control technology, and provides a clutch pre-fill oil control method and device. The method includes: obtaining the current gearbox oil temperature, accelerator pedal opening, and clutch front and rear end speed difference of the vehicle; determining the clutch pre-fill oil step target current according to the gearbox oil temperature, and determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the gearbox oil temperature; determining the target maintenance time of the clutch pre-fill oil maintenance target current according to the gearbox oil temperature and the clutch front and rear end speed difference, wherein the pre-fill oil maintenance target current is the current corresponding to the clutch desired pressure; when the clutch pre-fill oil control activation is detected, the clutch is controlled to maintain the step maintenance time for the pre-fill oil step target current, and the clutch is controlled to maintain the target maintenance time for the pre-fill oil maintenance target current. The present invention improves the efficiency and smoothness of the entire switching process.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a clutch pre-fill oil control method and device. Background Art

[0002] Hybrid vehicles combine the advantages of traditional internal combustion engines and electric motors, and optimize the distribution between the two through intelligent control systems to achieve better fuel economy, lower emissions and better power performance. When hybrid vehicles switch between series mode and parallel mode, the clutch engagement and disengagement needs to be very smooth to avoid negative impacts on vehicle power and ride comfort. Clutch pressure control can accurately adjust the degree of clutch engagement to ensure smooth mode switching.

[0003] In the related art, the clutch pre-filling oil control is usually controlled by fixed pressure and fixed time. The clutch engagement control is performed immediately after the front and rear end speeds of the clutch are synchronized. The entire mode switching process takes a long time or is not smooth enough. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a clutch pre-fill oil control method and device to solve the problem that the power mode switching process in the related art is not smooth enough.

[0005] A first aspect of an embodiment of the present invention provides a clutch pre-fill oil control method, comprising:

[0006] Get the vehicle's current transmission oil temperature, accelerator pedal opening, and clutch front and rear speed difference;

[0007] Determine the pre-fill oil step target current of the clutch according to the transmission oil temperature, and determine the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature;

[0008] According to the gearbox oil temperature and the speed difference between the front and rear ends of the clutch, the target maintenance time of the clutch pre-fill oil to maintain the target current is determined, wherein the pre-fill oil to maintain the target current is the current corresponding to the desired pressure of the clutch;

[0009] When clutch pre-fill oil control activation is detected, the clutch is controlled to maintain a step maintenance time for a pre-fill oil step target current, and the clutch is controlled to maintain the target maintenance time for a pre-fill oil maintenance target current.

[0010] A second aspect of an embodiment of the present invention provides a clutch pre-fill oil control device, comprising:

[0011] An acquisition module is configured to acquire the current transmission oil temperature, accelerator pedal opening, and clutch front and rear end speed difference of the vehicle;

[0012] A first determination module is configured to determine a pre-fill oil step target current of the clutch according to the transmission oil temperature, and determine a step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature;

[0013] The second determination module is configured to determine a target maintenance time of the clutch pre-fill oil to maintain a target current according to the transmission oil temperature and the front and rear end speed difference of the clutch, wherein the pre-fill oil maintenance target current is a current corresponding to a desired pressure of the clutch;

[0014] The control module is configured to control the clutch to maintain a step holding time for a pre-filling oil step target current and to control the clutch to maintain a target holding time for a pre-filling oil target current when the clutch pre-filling oil control is detected to be activated.

[0015] According to a third aspect of an embodiment of the present invention, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0016] According to a fourth aspect of an embodiment of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: by obtaining the current transmission oil temperature, accelerator pedal opening and clutch front and rear end speed difference of the vehicle, and determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and transmission oil temperature, it is possible to respond quickly and prevent unnecessary impacts, thereby shortening the clutch oil channel pressure building time. According to the transmission oil temperature and the clutch front and rear end speed difference, the target maintenance time of the clutch pre-fill oil maintenance target current is determined, wherein the pre-fill oil maintenance target current is the current corresponding to the desired clutch pressure, and the clutch pressure can be controlled more accurately by comprehensively considering the oil temperature and speed difference, making the engagement process smoother, and the pre-fill oil time can be adapted according to actual conditions to reduce the time required for the entire mode switch. When the clutch pre-fill oil control activation is detected, the clutch is controlled to maintain the step maintenance time for the pre-fill oil step target current, and the clutch is controlled to maintain the target maintenance time for the pre-fill oil target current, so that each stage can make appropriate adjustments according to the real-time situation, while shortening and eliminating the clutch idle travel time, avoiding the impact of the whole vehicle caused by premature engagement of the clutch during the speed synchronization adjustment process, thereby improving the efficiency and smoothness of the entire switching process and enhancing the power and economy of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a schematic diagram of an application scenario of an embodiment of the present application;

[0020] Figure 2 It is a flow chart of a clutch pre-fill oil control method provided in an embodiment of the present application;

[0021] Figure 3 It is a structural schematic diagram of a clutch pre-fill oil control device provided in an embodiment of the present application;

[0022] Figure 4 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0024] In series mode, the power transmission path of a hybrid vehicle is linear: the engine does not drive the wheels directly, but is used to drive the generator to generate electricity, which is used to charge the battery or directly supply the drive motor, which drives the wheels. In parallel mode, the engine and the drive motor can drive the vehicle independently or together. The engine can drive the wheels directly through the transmission mechanism, and can also charge the battery or supply the drive motor through the generator. In this mode, the engine and the motor can work independently or in conjunction to provide optimal efficiency and performance.

[0025] In urban traffic or low-speed driving conditions, the drive motor is more efficient than the internal combustion engine. At this time, the engine can be turned off or run in the most efficient way to generate electricity, while the drive motor directly drives the wheels, which not only reduces fuel consumption but also reduces emissions. In situations where continuous power output is required, such as on highways, the internal combustion engine is usually more efficient than the drive motor. Through parallel mode, the engine can directly drive the wheels and assist the drive motor to provide additional power as needed, thereby achieving optimal fuel efficiency.

[0026] When switching between series mode and parallel mode, the clutch engagement and disengagement needs to be smooth to avoid negative impacts on vehicle dynamics and ride comfort. Clutch pressure control can accurately adjust the degree of clutch engagement to ensure smooth mode switching. In related technologies, the clutch pre-filling oil control usually involves filling the clutch hydraulic chamber with oil at a predetermined pressure value or pre-filling the oil for a predetermined time length, and immediately performing clutch engagement control after the front and rear end speeds of the clutch are synchronized. The entire mode switching process is long or not smooth enough.

[0027] In view of the above scenario, the present application provides a clutch pre-fill oil control method, which divides the clutch pre-fill oil control process into two stages. The first stage is the clutch pre-fill oil step control stage, which directly requests a step target current from the solenoid valve and maintains it for a certain time (i.e., the step maintenance time). The second stage is the clutch pre-fill oil maintenance stage, which requests a pre-fill oil maintenance current and maintains it for a certain time (i.e., the target maintenance time). In the above two-stage control process, the current transmission oil temperature, accelerator pedal opening, and clutch front and rear end speed difference can be obtained, and the clutch pre-fill oil step target current is determined according to the transmission oil temperature. Considering that the oil temperature affects the viscosity of the hydraulic oil, and then affects the speed of the pre-fill oil, the accelerator pedal opening can reflect the driver's needs, and the step maintenance time of the pre-fill oil step target current is determined according to the accelerator pedal opening and the transmission oil temperature. The step maintenance time is the clutch oil channel pressure building time, so that it can respond quickly and prevent unnecessary impact, shortening the clutch oil channel pressure building time. According to the gearbox oil temperature and the speed difference between the front and rear ends of the clutch, the target maintenance time of the clutch pre-fill oil to maintain the target current is determined, where the pre-fill oil maintenance target current is the current corresponding to the expected pressure of the clutch. Taking the oil temperature and speed difference into consideration, the clutch pressure can be controlled more accurately, making the engagement process smoother, and the pre-fill oil time can be adapted according to the actual situation to reduce the time required for the entire mode switch. The clutch is controlled to maintain the step maintenance time for the pre-fill oil step target current, and the clutch is controlled to maintain the target maintenance time for the pre-fill oil to maintain the target current, so that each stage can be appropriately adjusted according to the real-time situation. While shortening and eliminating the clutch idle travel time, it avoids the impact of the whole vehicle caused by the early engagement of the clutch during the speed synchronization adjustment process, improves the efficiency and smoothness of the entire switching process, and improves the power and economy of the whole vehicle.

[0028] Figure 1The following is a schematic diagram of the application scenario of the embodiment of the present application. The engine 110 can be used to generate mechanical energy; the generator 120 can be used to convert the mechanical energy generated by the engine 110 into electrical energy; the first inverter 121 and the second inverter 123 can be used to convert direct current into alternating current or convert alternating current into direct current; the power battery 122 is a battery pack for storing electrical energy; the drive motor 130 can be used to convert electrical energy into mechanical energy to drive the wheels; the clutch 131 controls the connection between the engine and the drive system; the gearbox 140 can be used to adjust the transmission ratio so that the vehicle can adapt to different driving speeds.

[0029] In the series mode, after the engine 110 is started, the generator 120 is driven to operate through mechanical transmission, and the generator 120 converts mechanical energy into electrical energy. The generated electrical energy is converted into a form suitable for the power battery 122 by the first inverter 121 and stored. Alternatively, the electrical energy is directly transmitted to the drive motor 130 through the second inverter 123, and the drive motor 130 converts the electrical energy into mechanical energy and drives the wheels through the gearbox 140. In the series mode, the clutch 131 is in a disengaged state, and the engine 110 does not directly participate in driving the wheels.

[0030] In parallel mode, the engine 110 drives the wheels directly through the clutch 131 and the gearbox 140, the drive motor 130 can work alone or with the engine as needed, and the power battery 122 provides power to the drive motor 130 through the second inverter 123. In parallel mode, the clutch 131 is in an engaged state, allowing the engine 110 and the drive motor 130 to drive the wheels together. Through intelligent control, the above components can switch between series mode and parallel mode to achieve optimal fuel economy and driving performance, improving the power and economy of the entire vehicle.

[0031] A clutch pre-fill oil control method and device according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0032] Figure 2 1 is a flow chart of a clutch pre-fill oil control method provided in an embodiment of the present application. Figure 2 As shown, the clutch pre-fill oil control method includes:

[0033] Step 201, obtaining the current transmission oil temperature, accelerator pedal opening, and clutch front and rear end speed difference of the vehicle.

[0034] In some embodiments, the vehicle control unit (VCU) collects and analyzes the accelerator pedal opening, brake pedal status, transmission oil temperature, clutch pressure, etc. in real time, obtains the remaining power of the vehicle battery, the charging power of the vehicle battery, the vehicle speed, the expected torque at the engine shaft end, the engine cooling water temperature, the vehicle mode and other signals through the local area network control bus (Controller Area Network, CAN), and monitors the clutch fault status, solenoid valve fault status, and pressure sensor fault status in real time through the internal diagnostic module.

[0035] Vehicle mode refers to the current operating mode of the vehicle, such as pure electric mode, hybrid mode, etc. The internal diagnostic module can be built into the VCU to monitor and report the system health status. The internal diagnostic module can detect and record possible faults in real time, such as clutch failure, solenoid valve failure, pressure sensor failure, etc., so as to take corrective measures or remind maintenance in time.

[0036] In addition, the transmission oil can not only lubricate and cool the internal parts of the transmission, but also transmit power. The transmission oil temperature directly affects the viscosity of the hydraulic oil, which in turn affects the speed of the oil flow, thereby affecting the clutch filling process and control effect. When the transmission oil temperature is low, the oil is more viscous and flows slower, and the opposite is true at high temperatures.

[0037] The accelerator pedal opening can reflect the driver's acceleration intention. During the clutch pre-filling process, the size of the accelerator pedal opening affects the clutch engagement speed and power transmission efficiency. When the accelerator pedal opening is large, it can indicate that the driver intends to accelerate quickly, and at this time, the pre-filling needs to be completed faster to prepare for engagement.

[0038] The front end of the clutch refers to the part of the clutch close to the engine, that is, the part where the clutch plate contacts the flywheel. The rear end of the clutch refers to the part close to the transmission, that is, the part where the clutch plate contacts the input shaft of the transmission. The speed difference between the front and rear ends of the clutch refers to the speed difference between the front and rear ends of the clutch during the clutch engagement process. Among them, when the clutch is engaged, the speed of the front end (that is, the part where the clutch plate contacts the flywheel) will gradually increase, while the speed of the rear end (that is, the part where the clutch plate contacts the input shaft of the transmission) remains unchanged, and there is a certain speed difference between the two. The speed difference between the front and rear ends of the clutch is an important parameter to measure whether the engine and the motor are ready for smooth engagement. A smaller speed difference means that the front and rear ends of the clutch are easier to synchronize, and vice versa, it takes more time to synchronize the front and rear end speeds.

[0039] By monitoring the transmission oil temperature, the pre-filling rate and clutch filling pressure can be adjusted dynamically according to the transmission oil temperature to adapt to the lubrication effect and oil fluidity at different oil temperatures, ensuring the accuracy and stability of clutch filling. According to the accelerator pedal opening, the driver's acceleration needs can be judged, so as to adjust the clutch engagement speed and power transmission efficiency to achieve a smoother shifting and acceleration process. By monitoring the speed difference between the front and rear ends of the clutch, the clutch engagement point can be accurately controlled to avoid the impact of the whole vehicle caused by premature engagement of the clutch during the speed synchronization adjustment process, thereby improving the smoothness of the mode switching process and the driving stability of the vehicle.

[0040] Step 202, determining the pre-fill oil step target current of the clutch according to the transmission oil temperature, and determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature.

[0041] In some embodiments, the pre-filling oil step target current is a current value set to enable the clutch to reach the expected oil filling state. The pre-filling oil step target current is the required current in the stage where the vehicle quickly builds up the required pressure of the hydraulic system during the clutch pre-filling process. The stage where the vehicle quickly builds up the required pressure of the hydraulic system during the clutch pre-filling process can be called the pre-filling oil step control (Ramp control) stage.

[0042] In the pre-filling ramp control stage, the clutch oil pressure will rise in a nearly linear trend in a short period of time, forming a "ramp"-shaped pressure change curve. When the clutch oil pressure reaches a preset target value, the pre-filling ramp control stage ends.

[0043] During the clutch pre-filling process, the value of the pre-filling step target current needs to be adjusted according to the gearbox oil temperature so that the clutch can achieve a fast and accurate filling process at different oil temperatures. By determining the pre-filling step target current in the pre-filling step control stage, the clutch can reach the expected pre-filling pressure in a short time.

[0044] The accelerator pedal opening can reflect the driver's acceleration demand. The step maintenance duration is the time period during which the clutch pre-fill oil step target current remains at a stable value. The length of this time period needs to be adjusted according to the accelerator pedal opening and the transmission oil temperature to match the actual needs of the vehicle.

[0045] Through the current transmission oil temperature and accelerator pedal opening, the pre-fill oil step target current is maintained for the step maintenance time, which helps to shorten the clutch oil channel pressure building time. Compared with the traditional fixed parameter control method, this process ensures that the clutch oil pressure fills the oil channel as quickly as possible.

[0046] Step 203, determining a target maintenance time for the clutch pre-fill oil to maintain a target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, wherein the pre-fill oil maintenance target current is a current corresponding to a desired clutch pressure.

[0047] In some embodiments, the speed difference between the front and rear ends of the clutch can reflect the degree of synchronization between the front and rear ends of the clutch. A smaller speed difference means that the front and rear ends of the clutch are easier to engage synchronously, and a larger speed difference means that the front and rear ends of the clutch need more time to adjust.

[0048] Pre-fill oil maintains the target current so that the clutch reaches the desired pressure The desired clutch pressure can be the half-engagement pressure. It can be 2.5 bar. This application does not require the desired pressure of the clutch. Without limiting the above, the desired clutch pressure may be different for different models of vehicles.

[0049] The pre-fill oil maintains the target current to control the clutch pressure through the solenoid valve. The target maintenance duration is based on the transmission oil temperature and the speed difference between the front and rear ends of the clutch. The clutch pre-fill oil maintains the target current maintenance duration determined after comprehensive consideration, which helps to ensure that the clutch is engaged in the best state. This process eliminates the clutch oil cavity idle stroke while waiting for the series mode to switch to the parallel mode. The front and rear end speeds of the clutch are synchronized.

[0050] In addition, the pre-fill oil maintenance target current is the required current of the vehicle during the pre-fill oil maintenance (Hold) control stage. The target maintenance time enables a certain clutch pressure to be maintained for a period of time to ensure that the front and rear end speeds of the clutch are synchronized and prepare for actual engagement. The pre-fill oil maintenance control stage is the stage for maintaining the pre-fill oil maintenance target current for the target maintenance time.

[0051] By dynamically adjusting the target duration of the clutch pre-fill oil to maintain the target current, the appropriate clutch engagement conditions can be determined in the shortest time, reducing unnecessary waiting time, and helping the clutch oil pressure to quickly fill the oil channel, eliminate the clutch oil cavity empty stroke, and avoid overfilling the oil pressure beyond the clutch half-engagement point. By precisely controlling the clutch pressure, engagement is performed with the speed difference minimized, avoiding shock or vibration caused by speed asynchrony, providing a smoother driving experience.

[0052] Step 204 , when it is detected that the clutch pre-fill oil control is activated, the clutch is controlled to maintain a step holding time for the pre-fill oil step target current, and the clutch is controlled to maintain a target holding time for the pre-fill oil target current.

[0053] In some embodiments, the pre-fill oil step target current is determined according to the current transmission oil temperature to quickly fill the clutch oil channel and establish initial pressure, and the length of time the pre-fill oil step target current should be maintained (step maintenance duration) is determined according to the accelerator pedal opening and the transmission oil temperature, so that the engagement condition is quickly prepared at the driver's request. After the step maintenance duration ends, the pre-fill oil maintenance target current is determined according to the clutch expected pressure and the clutch actual pressure, and the target maintenance duration of the clutch pre-fill oil maintenance target current is determined according to the transmission oil temperature and the clutch front and rear end speed difference, so that the clutch front and rear end speed difference is reduced as much as possible within the target maintenance duration, so as to fully prepare for the clutch engagement.

[0054] The clutch pre-fill oil control in stages helps to build up initial pressure quickly and smoothly, shortening the clutch oil channel pressure building time. At the same time, the clutch pre-fill oil hold control (Hold control) stage time is adjusted by the transmission oil temperature and the speed difference between the front and rear ends of the clutch, so that engagement is performed under synchronized speed to avoid impact or vibration caused by asynchronous speed.

[0055] In this way, the present application first performs clutch pre-fill oil step control, that is, controls the clutch to maintain the step maintenance time for the pre-fill oil step target current. This process ensures that the clutch oil pressure fills the oil channel as quickly as possible; further performs clutch pre-fill oil retention control, that is, controls the clutch to maintain the target current for the pre-fill oil to maintain the target maintenance time. This process eliminates the clutch oil chamber empty stroke while waiting for the series mode to switch to the parallel mode and the front and rear end speeds of the clutch are synchronized. The whole process ensures that the clutch oil pressure quickly fills the oil channel and eliminates the clutch oil chamber empty stroke, while avoiding overcharging of the oil pressure exceeding the clutch half-engagement point, so that while shortening the time to eliminate the clutch empty stroke, the speed synchronization adjustment process can avoid premature engagement of the clutch to cause impact on the whole vehicle, thereby improving the power and economy of the whole vehicle.

[0056] In some embodiments, determining a clutch pre-fill oil step target current according to a transmission oil temperature includes:

[0057] Determine the pre-fill oil step target current according to the gearbox oil temperature and the first mapping relationship;

[0058] The first mapping relationship is used to indicate the mapping relationship between the transmission oil temperature and the pre-fill oil step current.

[0059] In some examples, in a first mapping relationship, when the transmission oil temperature is less than 0, the pre-fill oil step target current is less than a preset current value to match the load of the clutch, and when the transmission oil temperature is greater than or equal to 0, the pre-fill oil step target current is greater than or equal to the preset current value.

[0060] In some examples, the first mapping relationship may be a data table or function obtained through experiments or simulations. The first mapping relationship may describe the current value required to achieve fast and stable pressure under different oil temperature conditions, that is, describe what pre-filling oil step current should be set to achieve the best effect under different oil temperature conditions.

[0061] As an example, the first mapping relationship between the gearbox oil temperature and the pre-fill oil step current is shown in the following table:

[0062] Table 1 The first mapping relationship

[0063]

[0064] Based on the current gearbox oil temperature, the corresponding pre-fill oil step target current is queried. For example, if the current gearbox oil temperature is 40°C, the corresponding pre-fill oil step target current is 1000mA.

[0065] When the transmission oil temperature is below zero degrees, the oil becomes more viscous, and the pre-fill oil step target current is less than the preset current value to match the load of the clutch. When the transmission oil temperature is zero degrees or above, the oil fluidity is enhanced, and the response speed of the hydraulic system is accelerated. At this time, a higher current value is required to quickly build up sufficient hydraulic pressure. Therefore, when the transmission oil temperature is greater than or equal to zero, the pre-fill oil step target current is set to be greater than or equal to the preset current value to ensure that the necessary hydraulic pressure is built up in a shorter time, supporting efficient mode switching and smooth shifting experience. As an example, continue to refer to Table 1, the preset current value can be 1000mA.

[0066] By adjusting the pre-filling oil step current according to the transmission oil temperature, the clutch can quickly obtain the appropriate filling oil pressure at different oil temperatures, thereby preventing overfilling while ensuring that the oil pressure quickly fills the oil channel.

[0067] In some embodiments, determining the step duration of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature includes:

[0068] Determine the step duration of the pre-fill oil step target current according to the accelerator pedal opening, the transmission oil temperature and the second mapping relationship;

[0069] The second mapping relationship is used to indicate the mapping relationship between the accelerator pedal opening, the transmission oil temperature and the maintenance time of the pre-fill oil step target current.

[0070] In some examples, in the second mapping relationship, when the accelerator pedal opening is greater than or equal to a first preset opening value, or when the transmission oil temperature is greater than or equal to a preset oil temperature value and the accelerator pedal opening is greater than or equal to a second preset opening value, the maintenance duration of the pre-fill oil step target current is the maximum duration among the different set maintenance durations, and the first preset opening value is greater than the second preset opening value.

[0071] In some examples, the second mapping relationship is used to indicate the relationship between the accelerator pedal opening, the transmission oil temperature and the maintenance time of the pre-fill oil step target current. The second mapping relationship can be a multidimensional function or table, which can describe what step maintenance time should be set to achieve the best effect under different combinations of accelerator pedal opening and transmission oil temperature. The second mapping relationship can be obtained through engineering experience and actual three-high calibration tests during vehicle development, which helps to ensure that fast and smooth shifting can be achieved under various driving intentions and transmission temperature conditions. Specifically, the second mapping relationship is shown in the following table:

[0072] Table 2 Second mapping relationship

[0073]

[0074] In the above table, the first row is the accelerator pedal opening, the first column is the transmission oil temperature, and the remaining rows and columns except the first row and the first column are the step maintenance time corresponding to different transmission oil temperatures and accelerator pedal opening combinations. Therefore, based on the current accelerator pedal opening and transmission oil temperature, the step maintenance time of the corresponding pre-filling oil step target current can be queried. For example, when the accelerator pedal opening is 0% and the transmission oil temperature is 0, the step maintenance time is 0 ms; when the accelerator pedal opening is 20% and the transmission oil temperature is 40℃, a certain pre-filling oil time is required to prepare for engagement, and the step maintenance time is set to 40 ms; when the accelerator pedal opening is 80% and the transmission oil temperature is 40℃, it corresponds to the situation of rapid acceleration or high-speed driving, and a longer pre-filling oil time is required to ensure rapid and smooth pressure build-up, and the maintenance time is set to 80 ms.

[0075] In addition, when the accelerator pedal opening reaches or exceeds a higher threshold (i.e., the first preset opening value), it can be considered that the driver has a strong acceleration demand. A larger throttle opening usually means that sufficient hydraulic pressure needs to be quickly established to support rapid engagement. At this time, regardless of the transmission oil temperature, the maintenance time of the pre-filling oil step target current is set to the maximum value among the different maintenance times set. When the transmission oil temperature reaches or exceeds a certain temperature threshold, and the accelerator pedal opening also reaches or exceeds another higher threshold (i.e., the second preset opening value), it can be considered that the current working condition is suitable for efficient pre-filling oil operation, and the maintenance time of the pre-filling oil step target current is also set to the maximum value.

[0076] For example, as an example, referring to Table 2 above, the first preset opening value can be 100%, the second preset opening value can be 60%, the preset oil temperature value can be 40°C, and the set maintenance time includes 10ms, 20ms, 30ms, 40ms, 60ms and 80ms. Then, when the accelerator pedal opening is equal to 100%, or when the transmission oil temperature is greater than or equal to 40°C and the accelerator pedal opening is greater than or equal to 60%, the maintenance time of the pre-filling oil step current is the maximum time of 80ms.

[0077] In other embodiments, in the second mapping relationship, when the transmission oil temperature is the same, as the accelerator pedal opening increases, the maintenance time of the pre-fill oil step current increases; when the accelerator pedal opening is the same, as the transmission oil temperature increases, the maintenance time of the pre-fill oil step current increases.

[0078] For example, referring to Table 2 above, as an example, at 0°C, when the accelerator pedal opening increases from 0% to 100%, the maintenance time increases from 0ms to 80ms; when the accelerator pedal opening is 20%, the maintenance time increases from 10ms to 40ms when the transmission oil temperature changes from -40°C to 80°C. In addition, when the transmission oil temperature is low (such as -40°C, -20°C), even if the accelerator pedal opening is large but not maximum, the step maintenance time is relatively small. When the transmission oil temperature is high (such as 40°C, 60°C, 80°C), as the accelerator pedal opening increases, the step maintenance time increases significantly, for example, when the accelerator pedal opening increases from 40% to 60%, the step maintenance time increases from 40ms to 80ms.

[0079] Through the second mapping relationship, the step duration of the pre-fill oil step target current can be dynamically adjusted according to the current accelerator pedal opening and transmission oil temperature, and the pre-fill oil time can be flexibly adjusted according to different driving needs. By introducing real-time data feedback and the second mapping relationship, a more accurate and flexible pre-fill oil control strategy can be achieved, effectively solving the problem of long switching time or lack of smoothness in traditional fixed control methods.

[0080] In some embodiments, after determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the gearbox oil temperature, the method further includes:

[0081] Get the accelerator pedal change rate;

[0082] According to the accelerator pedal change rate and the third mapping relationship, a first duration correction factor is determined, and the third mapping relationship is used to indicate the mapping relationship between the accelerator pedal change rate and the first duration correction factor; according to the first duration correction factor, the step maintenance duration of the pre-filling oil step target current is corrected to obtain a first corrected step maintenance duration, so that the pre-filling oil step target current maintains the first corrected step maintenance duration.

[0083] In some examples, the system continuously monitors the position of the accelerator pedal and calculates the accelerator pedal change rate (i.e., the change in the accelerator pedal opening per unit time). The accelerator pedal change rate can reflect the speed at which the driver accelerates or decelerates, which helps to more accurately determine the current driving intention and further optimize the pre-filling control strategy.

[0084] The third mapping relationship describes the mapping relationship between the accelerator pedal change rate and the first duration correction factor. When the clutch pre-fill oil control is activated, the first duration correction factor is calculated based on the accelerator pedal change rate. Since the faster the accelerator pedal changes, the stronger the power demand, and the need to quickly switch to parallel mode, the larger the correction factor is, and the step current action time is appropriately extended to allow the oil pressure to quickly fill the oil channel. Therefore, the accelerator pedal change rate and the first duration correction factor are positively correlated. When the accelerator pedal change rate increases, the first duration correction factor will also increase accordingly. The third mapping relationship can be used to convert the accelerator pedal change rate into the first duration correction factor. Normally, the first duration correction factor is less than 1.

[0085] The third mapping relationship can be formulated based on experimental data and engineering experience to ensure that the first duration correction factor can reasonably reflect the driver's acceleration intention under different accelerator pedal change rates. Specifically, the third mapping relationship is shown in Table 3 below:

[0086] Table 3 The third mapping relationship

[0087]

[0088] Through the third mapping relationship, the corresponding first duration correction factor can be determined according to the accelerator pedal change rate, and the first duration correction factor is used to subsequently adjust the step maintenance duration of the pre-filling oil step target current to more accurately match the driver's acceleration intention. After determining the first duration correction factor, it is applied to the step maintenance duration of the pre-filling oil step target current to correct the step maintenance duration to obtain a corrected maintenance duration (i.e., the first corrected step maintenance duration).

[0089] As an example, the duration of the first correction step can be determined by the following formula:

[0090]

[0091] in, is the duration of the first correction step, The duration of the step target current of the pre-fill oil step. is the first duration correction factor.

[0092] As another example, when determining the first correction step maintenance time, the step maintenance time of the pre-filling oil step target current can also be calculated first. and The product of , and then the step duration of the pre-fill oil step target current and the product Perform weighted summation to obtain the first correction step maintenance time; where, The corresponding preset weight value is greater than The corresponding preset weight value.

[0093] After the correction step maintenance time, the duration of the pre-filling oil step target current can be controlled according to the corrected maintenance time (the first corrected step maintenance time), that is, the clutch is controlled to maintain the first corrected step maintenance time for the pre-filling oil step target current, which helps to ensure that the clutch obtains sufficient pressure and flow during the filling process to achieve smooth engagement and power transmission. At the same time, since the correction is based on the driver's acceleration intention, the clutch filling process is more in line with the driver's acceleration intention, thereby improving the smoothness and response speed of the gear shift, and improving the driving comfort and safety.

[0094] In some embodiments, when it is detected that the driver intends to exit the clutch engagement operation and the pre-filling oil control is activated again, if the time interval between the two pre-filling oil control activations is less than the preset time interval and the transmission oil temperature is greater than or equal to zero, the second duration correction factor is determined according to the time interval between the two pre-filling oil control activations and a fourth mapping relationship; the fourth mapping relationship is used to indicate the mapping relationship between the time interval between the two pre-filling oil control activations and the second duration correction factor;

[0095] According to the first time correction factor, the second time correction factor and the step maintenance time of the pre-filling oil step target current, the second corrected step maintenance time is determined so that the pre-filling oil step target current maintains the second corrected step maintenance time during the re-pre-filling oil control process.

[0096] In some examples, it may be detected through sensors and other inputs (eg, accelerator pedal position, brake pedal status, etc.) whether the driver intends to exit the current clutch engagement operation and whether the pre-fill control is activated again.

[0097] When the clutch is in the pre-oil control process, if the driver intends to change the pre-oil control after exiting the clutch engagement, the pre-oil control needs to be reactivated. The step current maintenance time of the step control stage needs to be further adjusted to reduce the risk of clutch overcharging. The time interval between the two pre-oil control activations is calculated based on the time points recorded by the system. When it is detected that the driver intends to exit the clutch engagement operation and the pre-oil control is activated again, if the time interval between the two pre-oil control activations is less than the preset time interval and the transmission oil temperature is greater than or equal to zero, the corresponding second time correction factor can be found in the fourth mapping relationship based on the calculated interval time ΔT.

[0098] Specifically, the fourth mapping relationship can describe the time interval ΔT between two activations of the pre-filling oil control and the second time correction factor: The mapping relationship between them is negatively correlated. When the time interval ΔT increases, the second time correction factor Decrease; otherwise increase. Generally, the second duration correction factor is greater than or equal to 0 and less than or equal to 1. The fourth mapping relationship is shown in the following table:

[0099] Table 4 Fourth mapping relationship

[0100]

[0101] According to the calculated time interval ΔT, the corresponding correction factor β is found in the above Table 4. For example, if the time interval ΔT is 60ms, the corresponding second time correction factor is If the time interval does not belong to the above table, the corresponding second time correction factor can be estimated by linear interpolation or attribution to a similar time interval. .

[0102] Maintain the target current step of the pre-fill oil step for a certain period of time and the first duration correction factor and the second duration correction factor Combined, the final second correction step maintenance duration is calculated , so that the duration can be maintained according to the modified second correction step Adjust the operation of the solenoid valve so that in the pre-fill oil control after the pre-fill oil is activated again, the pre-fill oil step target current maintains the second correction step maintenance time .

[0103] When it is detected that the driver intends to exit the clutch engagement operation and the pre-fill oil control is activated again, the second duration correction factor is determined according to specific conditions, and finally the second correction step maintenance duration is determined. By dynamically adjusting the step maintenance duration, the required hydraulic pressure can be quickly established when the driver operates quickly, shortening the switching time, and helping to avoid gear shift shock caused by insufficient or excessive pre-fill oil, thereby improving the smoothness and comfort of gear shifting.

[0104] In some embodiments, determining the second corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-fill oil step target current includes:

[0105] Determine a third corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-fill oil step target current;

[0106] When the third correction step maintenance time is longer than the maximum time of the set pre-filling oil step target current maintenance time, the maximum time of the pre-filling oil step target current maintenance time is determined as the second correction step maintenance time;

[0107] When the third correction step maintaining time is less than or equal to the maximum time among the set maintaining time of the pre-filling oil step target current, the third correction step maintaining time is determined as the second correction step maintaining time.

[0108] In some examples, when determining the third corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-fill oil step target current, it can be determined by the following formula: Third corrected step maintenance time = ( .

[0109] In other examples, when determining the duration of the third correction step, the following can also be calculated: ( , then and ( The weighted sum of is determined as the third correction step maintenance duration, where ( The corresponding preset weight value is greater than The corresponding preset weight value.

[0110] In addition, as an example, the second corrected step maintenance time can be determined according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-filling oil step target current by referring to the following formula:

[0111] (

[0112] in is the duration of the second correction step, is the first duration correction factor, is the second duration correction factor, The duration of the step target current of the pre-fill oil step. ( The duration of the third correction step. The maximum action time of the clutch pre-fill oil step control stage, that is, the maximum duration of the clutch pre-fill oil step target current maintenance time, refer to Table 2, at this time The maximum value of the maintenance time of the set pre-filling oil step target current can be used to prevent the pre-filling oil operation from being too long, thereby protecting the hydraulic system and mechanical components.

[0113] By determining the final second corrected step maintenance duration based on the first duration correction factor, the second duration correction factor and the step maintenance duration of the pre-filling oil step target current, the limitations of the traditional fixed parameter control method are overcome, and the vehicle's performance under different driving conditions is significantly improved, providing users with a more efficient and comfortable driving experience.

[0114] In some embodiments, determining a target maintenance time for the clutch pre-fill oil to maintain a target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch includes:

[0115] Determine the target maintenance time of the pre-fill oil to maintain the target current according to the transmission oil temperature, the speed difference between the front and rear ends of the clutch and the fifth mapping relationship;

[0116] The fifth mapping relationship is used to indicate the mapping relationship between the transmission oil temperature, the speed difference between the front and rear ends of the clutch, and the maintenance time of the pre-filled oil to maintain the target current.

[0117] In some examples, in the fifth mapping relationship, when the transmission oil temperature is the same, the absolute value of the speed difference between the front and rear ends of the clutch is positively correlated with the maintenance time of the pre-filled oil to maintain the target current; when the absolute value of the speed difference between the front and rear ends of the clutch is the same, if the transmission oil temperature is less than 0, then the transmission oil temperature is negatively correlated with the maintenance time of the pre-filled oil to maintain the target current.

[0118] In some examples, the speed difference between the front and rear ends of the clutch can be determined according to the following formula:

[0119]

[0120] in, is the speed difference between the front and rear ends of the clutch, is the engine speed, is the driving motor speed, is the speed ratio of the drive motor speed to the wheel speed, is the ratio of engine speed to wheel speed.

[0121] The fifth mapping relationship can reflect the gearbox oil temperature, the speed difference between the front and rear ends of the clutch, and the target maintenance time of the pre-fill oil to maintain the target current. The fifth mapping relationship can be obtained through experimental data, empirical formulas or machine learning models, and is used to guide the clutch pre-filling oil control strategy. When the current is the pre-filling oil to maintain the target current stage, the clutch pressure is basically maintained stable and also approaches the clutch expected pressure. The fifth mapping relationship is shown in the following table:

[0122] Table 5 Fifth mapping relationship

[0123]

[0124] In the fifth mapping relationship, when the transmission oil temperature is the same, the absolute value of the speed difference between the front and rear ends of the clutch is positively correlated with the duration of the pre-fill oil to maintain the target current. When the transmission oil temperature remains unchanged, the greater the absolute value of the speed difference between the front and rear ends of the clutch, the longer the required pre-fill oil maintenance time. For example, when the transmission oil temperature is 0°C: when the speed difference between the front and rear ends of the clutch is -2000rpm, the maintenance time is 200ms, and when the speed difference between the front and rear ends of the clutch is -500rpm, the maintenance time is 100ms.

[0125] When the absolute value of the speed difference between the front and rear ends of the clutch is the same, if the transmission oil temperature is less than 0, the transmission oil temperature is negatively correlated with the maintenance time of the pre-fill oil to maintain the target current, that is, when the speed difference between the front and rear ends of the clutch is the same but the transmission oil temperature is below zero, the lower the transmission oil temperature, the longer the required pre-fill oil maintenance time. For example, when the speed difference is -500rpm: when the transmission oil temperature is -40℃, the maintenance time is 200ms, and when the transmission oil temperature is -20℃, the maintenance time is 150ms.

[0126] In other embodiments, when the absolute value of the speed difference between the front and rear ends of the clutch is the same, if the gearbox oil temperature is greater than or equal to 0, the maintenance time of the pre-fill oil corresponding to different gearbox oil temperatures to maintain the target current is the same, that is, when the gearbox oil temperature is greater than or equal to 0, the maintenance time of the pre-fill oil to maintain the target current is only related to the speed difference between the front and rear ends of the clutch. For example, as an example, when the speed difference is -500rpm and the gearbox oil temperature is greater than or equal to 0, the maintenance time is 100ms.

[0127] According to the current transmission oil temperature and the speed difference between the front and rear ends of the clutch, the fifth mapping relationship is queried to determine the target maintenance time of the pre-fill oil to maintain the target current. For different oil temperature and speed difference conditions, the target maintenance time of the target current is maintained by the appropriate pre-fill oil to quickly respond to the driver's needs, so that under various working conditions, while shortening and eliminating the clutch idle travel time, the speed synchronization adjustment process can avoid premature clutch engagement and vehicle impact, achieving more accurate and flexible pre-fill oil control, and effectively solving the problem of long switching time or lack of smoothness in traditional fixed control methods.

[0128] In some embodiments, after determining the target maintenance time of the clutch pre-fill oil to maintain the target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, the method further includes:

[0129] When the speed difference between the front and rear ends of the clutch is less than the preset speed difference, the actual speed of the generator for a preset number of consecutive cycles is obtained, and the speed variance of the generator is determined according to the actual speed of the generator for the preset number of cycles;

[0130] Determine a third duration correction factor according to the gearbox oil temperature, the generator speed variance and a sixth mapping relationship; the sixth mapping relationship is used to indicate a mapping relationship between the gearbox oil temperature, the generator speed variance and the third duration correction factor;

[0131] According to the third duration correction factor, the target maintenance duration for the clutch's pre-fill oil to maintain the target current is corrected to obtain the corrected maintenance duration; according to the corrected maintenance duration, the final maintenance duration for the clutch's pre-fill oil to maintain the target current is determined so that the pre-fill oil maintains the target current for the final maintenance duration.

[0132] In some examples, in the sixth mapping relationship, when the transmission oil temperature is the same, the generator speed variance is positively correlated with the third duration correction factor; when the generator speed variance is the same and less than the preset variance value, the third duration correction factor corresponding to the transmission oil temperature is less than 0 is greater than the third duration correction factor corresponding to the transmission oil temperature is greater than or equal to 0.

[0133] In some examples, during the clutch pre-fill oil holding stage, that is, the time period corresponding to the pre-fill oil maintaining the target current, the generator drags the engine to follow the drive motor speed to complete the speed control. During this stage, the drive motor speed changes, and the duration of this stage needs to be determined by the generator speed variance. (i.e., the target duration of maintaining the target current by pre-filling oil) is further dynamically corrected; when the speed difference between the front and rear ends of the clutch is lower than the preset speed difference, the actual speed of the generator for consecutive preset cycles is obtained, and the generator speed variance is determined based on the actual speed of the generator for the preset cycles .

[0134] In some examples, the preset period may be 5 periods, and the generator speed variance may be obtained by the following formula:

[0135] in, is the generator speed variance, is the actual speed of the generator in the ith cycle among n cycles, is the average speed of the generator over n cycles.

[0136] By monitoring the actual speed of the generator, we can more accurately understand the current power transmission situation and provide a basis for subsequent adjustments. The generator speed variance can reflect the stability of the power output and help identify whether there are abnormal fluctuations or unstable factors. The larger the value of the generator speed variance, the longer the maintenance time needs to be appropriately extended. The smaller the value of the generator speed variance, the more stable the speed regulation is, and the maintenance time can be appropriately shortened.

[0137] According to the gearbox oil temperature and the generator speed variance, the corresponding third duration correction factor is searched in the sixth mapping relationship. The sixth mapping relationship can be a function or a mapping table, which establishes a mathematical relationship or corresponding rule between the two parameters of the gearbox oil temperature and the generator speed variance and the third duration correction factor. The establishment of the sixth mapping relationship can be based on a large amount of experimental data or engineering experience and actual three-high calibration tests, which is used to guide how to adjust the clutch pre-fill oil to maintain the target current under different working conditions. The sixth mapping relationship is shown in the following table:

[0138] Table 6 Sixth mapping relationship

[0139]

[0140] In the sixth mapping relationship, when the generator speed variance is 0, no matter what the gearbox oil temperature is, the third time correction factor is 0, that is, when the generator speed is very stable, no additional correction time is required. As the generator speed variance increases, under the same gearbox oil temperature, the generator speed variance is positively correlated with the third time correction factor, that is, when the gearbox oil temperature remains unchanged, the larger the generator speed variance, the larger the corresponding third time correction factor. For example, when the gearbox oil temperature is 0℃: when the generator speed variance is 0, the third time correction factor is 0, when the generator speed variance is 10 rpm², the third time correction factor is 0.1, and when the generator speed variance is 20 rpm², the third time correction factor is 0.15.

[0141] When the generator speed variance is the same and less than the preset variance value, the third time correction factor corresponding to when the gearbox oil temperature is less than 0 is greater than the third time correction factor corresponding to when the gearbox oil temperature is greater than or equal to 0, that is, when the generator speed variance is the same but lower than the preset variance value, if the gearbox oil temperature is below zero degrees, a larger third time correction factor is required; otherwise it is smaller, for example, when the generator speed variance is 10: when the gearbox oil temperature is -20°C, the third time correction factor is 0.15, and when the gearbox oil temperature is 20°C, the third time correction factor is 0.1.

[0142] In other embodiments, in the sixth mapping relationship, when the transmission oil temperature is less than 0, the third time correction factors corresponding to different transmission oil temperatures are the same and are the first value; when the transmission oil temperature is greater than or equal to 0, the third time correction factors corresponding to different transmission oil temperatures are the same and are the second value, wherein under the same generator speed variance, the second value is less than the first value.

[0143] According to the current gearbox oil temperature and the calculated generator speed variance, the corresponding third duration correction factor is searched in the sixth mapping relationship. Then, according to the third duration correction factor , the target maintenance time for the clutch pre-fill oil to maintain the target current is corrected to obtain a more accurate corrected maintenance time that conforms to the actual working conditions, and based on the corrected maintenance time, the final maintenance time for the clutch pre-fill oil to maintain the target current is determined, and the solenoid valve operation is adjusted based on the final maintenance time so that the pre-fill oil maintains the target current for the final maintenance time, which is the result of dynamic adjustment and optimization, and is more in line with the current working environment and needs.

[0144] In some examples, when determining the corrected maintenance duration, The product of is determined as the corrected maintenance duration, where To maintain the target duration, is the third duration correction factor. In addition, in some other examples, it is also possible to first calculate Then the target duration is Multiplying The weighted sum of is determined as the corrected maintenance duration; among which, The corresponding preset weight value is greater than The corresponding preset weight value.

[0145] By introducing a third duration correction factor and dynamically adjusting the duration for which the pre-fill oil is maintained to maintain the target current, the clutch can better adapt to different operating conditions, thereby improving the vehicle's flexibility and adaptability during the clutch pre-fill oil process. By dynamically adjusting the duration for which the pre-fill oil is maintained to maintain the target current, the clutch can maintain a stable working state under different operating conditions, thereby improving the reliability and service life of the clutch.

[0146] In some embodiments, determining a final maintenance time for the clutch pre-fill oil to maintain the target current according to the corrected maintenance time includes:

[0147] When the corrected maintenance time is greater than the maximum time among the set maintenance time of the pre-filling oil to maintain the target current, the maximum time among the maintenance time of the pre-filling oil to maintain the target current is determined as the final maintenance time;

[0148] When the corrected maintenance time is less than or equal to the maximum time among the set maintenance time of the pre-fill oil to maintain the target current, the corrected maintenance time is determined as the final maintenance time.

[0149] In some examples, the final maintenance time for the clutch pre-fill oil to maintain the target current can be determined according to the corrected maintenance time by the following formula:

[0150] ;

[0151] in, To maintain the final duration, To maintain the target duration, is the third duration correction factor, To maintain the duration after correction, The maximum action time of the clutch pre-fill oil maintenance control phase is defined as the maximum duration of the pre-fill oil maintenance target current.

[0152] As an example, referring to Table 5, the maximum duration is 300ms. The maximum duration of the set pre-filling oil maintenance target current maintenance duration can be used to prevent the pre-filling oil operation from being too long, thereby protecting the hydraulic system and mechanical components.

[0153] In the above formula, the smaller value of the maximum time between the corrected maintenance time and the maintenance time of the pre-filling oil to maintain the target current is determined as the final maintenance time.

[0154] By determining the final maintenance time of the clutch's pre-fill oil to maintain the target current based on the corrected maintenance time, the limitations of the traditional fixed parameter control method are overcome, the clutch is dynamically adjusted according to different working conditions and needs, and the maintenance time of the clutch's pre-fill oil to maintain the target current is accurately controlled, significantly improving the vehicle's performance under different driving conditions.

[0155] In some embodiments, controlling the clutch to maintain a step holding time for a pre-fill oil step target current, and controlling the clutch to maintain a target holding time for a pre-fill oil target current, includes:

[0156] Sending a step request signal to the solenoid valve of the clutch, wherein the step request signal carries a pre-fill oil step target current and a step maintenance time, so as to control the solenoid valve to perform opening control based on the pre-fill oil step target current and maintain the step maintenance time; and,

[0157] According to the expected pressure of the clutch and the actual pressure of the clutch, closed-loop control is used to determine the pre-fill oil maintenance target current corresponding to the clutch, and a holding request signal is sent to the solenoid valve of the clutch, wherein the holding request signal carries the pre-fill oil maintenance target current and the target maintenance time, so as to control the solenoid valve to perform opening control based on the pre-fill oil maintenance target current and maintain the target maintenance time.

[0158] In some embodiments, after the clutch solenoid valve receives the step request signal, the clutch solenoid valve adjusts its opening according to the received pre-fill oil step target current value, quickly starts filling the clutch oil channel, maintains the pre-fill oil step target current unchanged, and continues the step maintenance time, quickly building up a certain oil pressure in a short time to prepare for the next engagement. This stage is open-loop control, which quickly builds up hydraulic pressure and reduces the time required for pre-filling oil, so that the vehicle's clutch pre-filling oil control can respond faster to adapt to the driver's needs and transmission oil temperature.

[0159] In addition, optionally, the clutch pre-fill oil maintenance target current can be obtained by: obtaining the current actual clutch pressure; and determining the clutch pre-fill oil maintenance target current using a proportional-integral control method based on the clutch desired pressure and the clutch actual pressure.

[0160] Among them, the difference between the expected pressure and the actual pressure of the clutch is obtained in real time. According to the difference between the expected pressure and the actual pressure, the pre-fill oil maintenance target current can be obtained through a closed-loop control algorithm (such as a PID control algorithm) to more accurately control the clutch oil pressure and gradually adjust the clutch pressure to the desired pressure level.

[0161] In addition, a hold request signal is sent to the clutch solenoid valve, which carries the pre-fill oil maintenance target current and target maintenance time. The clutch solenoid valve adjusts the clutch solenoid valve opening according to the received pre-fill oil maintenance target current value, continues to maintain appropriate hydraulic pressure, maintains the pre-fill oil maintenance target current value unchanged, and continues the target maintenance time to ensure that it is ready for the next engagement in a short time.

[0162] Through the above two-stage control strategy, the vehicle can achieve more intelligent, fast and smooth switching between series mode and parallel mode, which can not only shorten the overall switching time, but also improve the comfort and efficiency of the switching process. Compared with the traditional fixed parameter control method, it improves the performance of the vehicle under different working conditions and provides users with a more efficient and comfortable driving experience.

[0163] In some embodiments, after controlling the clutch to maintain the target current and target duration for the pre-fill oil, the method further includes:

[0164] When it is detected that the clutch is filling oil with the pre-fill oil to maintain the target current and maintain the target maintenance time, and the current speed difference between the front and rear ends of the clutch is less than a preset threshold, the clutch is controlled to engage.

[0165] In some examples, the clutch is monitored for using pre-filled oil to maintain a target current for a target holding time, and the speed difference between the front and rear ends of the clutch is continuously monitored, that is, the current speed difference between the front and rear ends of the clutch. When the monitored speed difference is less than the set preset threshold and the pre-filled oil maintains the target current for a target holding time, it can be considered that this is the most suitable time for engagement. At this time, the speeds of the front and rear ends of the clutch are almost synchronized, and the clutch pressure is increased to achieve a smooth and fast engagement process. Controlling the clutch engagement can minimize the impact, reduce the mechanical stress caused by excessive speed difference, extend the service life of the clutch and related transmission components, and improve the smoothness and comfort of the clutch engagement, so that the vehicle can achieve a more intelligent, fast and smooth switching between series mode and parallel mode.

[0166] In some embodiments, detecting that a clutch pre-fill control of a vehicle is activated includes:

[0167] When the vehicle meets the preset activation conditions for pre-filling oil, it is determined that the clutch pre-filling oil control of the vehicle is activated; the preset activation conditions include:

[0168] The clutch system is in a fault-free state, the remaining power of the vehicle battery is greater than the preset remaining power, the charging power of the vehicle battery is greater than the preset power, the accelerator pedal opening is less than the preset opening, the vehicle speed is greater than the preset speed, the expected torque at the engine shaft end is greater than the preset torque, and the engine cooling water temperature is greater than the preset temperature.

[0169] When it is determined that the state of the vehicle meets the preset activation condition, it is determined that the clutch of the vehicle needs to be pre-filled with oil.

[0170] Through the internal diagnostic module, possible faults such as clutch fault, solenoid valve fault, pressure sensor fault, etc. are detected in real time to ensure that key components such as clutch, solenoid valve and pressure sensor do not detect any faults, and ensure that all hardware involved in mode switching is in normal working condition to prevent accidents or damage caused by faults.

[0171] The remaining power (State of Charge, SOC) of the vehicle battery is greater than the preset remaining power, which can be 5%. When the remaining power (State of Charge, SOC) of the vehicle battery is greater than the preset remaining power, it can ensure that there is sufficient power to support the working requirements of the motor during the mode switching, avoiding performance degradation or inability to complete the switching due to insufficient power.

[0172] The preset power may be 15 kilowatts, and a vehicle battery charging power greater than the preset power may indicate that the vehicle has sufficient power supply capability to utilize both the engine and the electric motor to provide power and charge the battery in parallel mode.

[0173] The preset opening can be 70%. Limiting the accelerator pedal opening to below the preset opening can limit the degree of acceleration request and prevent shock or instability that may be caused by mode switching under high load conditions.

[0174] The vehicle speed is greater than the preset speed, which can be 70km / h. At higher speeds, direct engine drive is more conducive to exerting its efficiency advantage, while also reducing the burden of the drive motor working alone. When driving at high speeds, the engine is more efficient and is therefore more suitable for parallel mode.

[0175] The preset torque may be 10 Nm. When the expected torque at the shaft end of the engine is greater than the preset torque, it may indicate that the vehicle is in a state requiring greater driving force and is suitable for a parallel mode in which the engine directly participates in the driving.

[0176] The preset temperature may be 30°C. When the engine's cooling water temperature is greater than the preset temperature, the engine has been fully preheated and has reached the optimal operating temperature range, making it suitable for immediately entering the efficient parallel mode.

[0177] If all the above conditions are met, it means that the vehicle needs to switch from series mode to parallel mode and activate the clutch pre-filling oil control. Otherwise, the clutch pre-filling oil control will not be activated.

[0178] The present application performs open-loop control of the clutch pre-fill oil step control phase according to the transmission oil temperature and the accelerator pedal opening (i.e., controls the clutch to maintain the step maintenance time for the pre-fill oil step target current), shortens the clutch oil channel pressure building time, and at the same time adjusts the clutch pre-fill oil control phase time through the transmission oil temperature and the front and rear end speed difference of the clutch (i.e., controls the clutch to maintain the target current for the pre-fill oil to maintain the target maintenance time), while shortening and eliminating the clutch idle stroke time, avoiding the impact on the whole vehicle caused by premature engagement of the clutch during the speed synchronization adjustment process, further shortening the mode switching time, and improving the power and economy of the whole vehicle.

[0179] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0180] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0181] Figure 3 Schematic diagram of a clutch pre-fill oil control device provided in an embodiment of the present application. Figure 3 As shown, the clutch pre-fill oil control device includes:

[0182] The acquisition module 301 is configured to acquire the current transmission oil temperature, accelerator pedal opening, and clutch front and rear end speed difference of the vehicle;

[0183] A first determination module 302 is configured to determine a pre-fill oil step target current of the clutch according to the transmission oil temperature, and determine a step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature;

[0184] The second determination module 303 is configured to determine a target maintenance time for the clutch pre-fill oil to maintain a target current according to the transmission oil temperature and the front and rear end speed difference of the clutch, wherein the pre-fill oil maintenance target current is a current corresponding to a desired clutch pressure;

[0185] The control module 304 is configured to control the clutch to maintain a step holding time for a pre-filling oil step target current and control the clutch to maintain a target holding time for a pre-filling oil target current when the clutch pre-filling oil control is detected to be activated.

[0186] In some embodiments, the first determination module 302 is configured to determine the pre-fill oil step target current according to the transmission oil temperature and the first mapping relationship; wherein the first mapping relationship is used to indicate the mapping relationship between the transmission oil temperature and the pre-fill oil step current.

[0187] In some embodiments, the first determination module 302 is configured to determine the step maintenance duration of the pre-fill oil step target current based on the accelerator pedal opening, the transmission oil temperature and the second mapping relationship; wherein the second mapping relationship is used to indicate the mapping relationship between the accelerator pedal opening, the transmission oil temperature and the maintenance duration of the pre-fill oil step target current.

[0188] In some embodiments, the first determination module 302 is configured to obtain the accelerator pedal change rate; determine the first duration correction factor based on the accelerator pedal change rate and the third mapping relationship, and the third mapping relationship is used to indicate the mapping relationship between the accelerator pedal change rate and the first duration correction factor; according to the first duration correction factor, correct the step maintenance time of the pre-fill oil step target current to obtain a first corrected step maintenance time, so that the pre-fill oil step target current maintains the first corrected step maintenance time.

[0189] In some embodiments, the first determination module 302 is configured to determine the second duration correction factor according to the time interval between the two pre-filling oil control activations and the fourth mapping relationship when it is detected that the driver intends to exit the clutch engagement operation and the pre-filling oil control is activated again, if the time interval between the two pre-filling oil control activations is less than the preset time interval and the transmission oil temperature is greater than or equal to zero; the fourth mapping relationship is used to indicate the mapping relationship between the time interval between the two pre-filling oil control activations and the second duration correction factor; determine the second corrected step maintenance time according to the first duration correction factor, the second duration correction factor and the step maintenance time of the pre-filling oil step target current, so that the pre-filling oil step target current maintains the second corrected step maintenance time during the re-pre-filling oil control process.

[0190] In some embodiments, the first determination module 302 is configured to determine the third corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-filling oil step target current; when the third corrected step maintenance time is greater than the maximum maintenance time of the set pre-filling oil step target current, the maximum maintenance time of the pre-filling oil step target current is determined as the second corrected step maintenance time; when the third corrected step maintenance time is less than or equal to the maximum maintenance time of the set pre-filling oil step target current, the third corrected step maintenance time is determined as the second corrected step maintenance time.

[0191] In some embodiments, the second determination module 303 is configured to determine the target maintenance time for the pre-fill oil to maintain the target current based on the transmission oil temperature, the speed difference between the front and rear ends of the clutch, and a fifth mapping relationship; wherein the fifth mapping relationship is used to indicate the mapping relationship between the transmission oil temperature, the speed difference between the front and rear ends of the clutch, and the maintenance time for the pre-fill oil to maintain the target current.

[0192] In some embodiments, the second determination module 303 is configured to obtain the actual speed of the generator for a preset number of consecutive cycles when the speed difference between the front and rear ends of the clutch is less than the preset speed difference, and determine the generator speed variance based on the actual speed of the generator for the preset number of cycles; determine the third duration correction factor based on the gearbox oil temperature, the generator speed variance and the sixth mapping relationship; the sixth mapping relationship is used to indicate the mapping relationship between the gearbox oil temperature, the generator speed variance and the third duration correction factor; according to the third duration correction factor, correct the target maintenance time of the clutch's pre-fill oil to maintain the target current to obtain the corrected maintenance time; according to the corrected maintenance time, determine the final maintenance time of the clutch's pre-fill oil to maintain the target current, so that the pre-fill oil maintains the target current for the final maintenance time.

[0193] In some embodiments, the second determination module 303 is configured to determine the maximum maintenance time of the pre-filling oil to maintain the target current as the final maintenance time when the corrected maintenance time is greater than the maximum maintenance time of the pre-filling oil to maintain the target current; and to determine the corrected maintenance time as the final maintenance time when the corrected maintenance time is less than or equal to the maximum maintenance time of the pre-filling oil to maintain the target current.

[0194] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0195] Figure 4 Schematic diagram of an electronic device provided in an embodiment of the present application. Figure 4 As shown, the electronic device of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 401 executes the computer program 403, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0196] The electronic device may be a desktop computer, a notebook, a PDA, a cloud server, etc. The electronic device may include but is not limited to a processor 401 and a memory 402. Those skilled in the art will appreciate that Figure 4 The electronic device is merely an example and does not limit the electronic device, and may include more or less components than those shown in the figure, or different components.

[0197] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0198] The memory 402 may be an internal storage unit of the electronic device, for example, a hard disk or memory of the electronic device. The memory 402 may also be an external storage device of the electronic device, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device. The memory 402 may also include both an internal storage unit of the electronic device and an external storage device. The memory 402 is used to store computer programs and other programs and data required by the electronic device.

[0199] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0200] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. The computer program may include computer program code, and the computer program code may be in source code form, object code form, executable file or some intermediate form. The computer readable medium may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electric carrier signals and telecommunication signals.

[0201] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A clutch pre-fill oil control method, applied to a hybrid vehicle switching between a series mode and a parallel mode, characterized in that: include: Get the vehicle's current transmission oil temperature, accelerator pedal opening, and clutch front and rear speed difference; Determining a pre-fill oil step target current of the clutch according to the transmission oil temperature, and determining a step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature; Determine the target maintenance time of the clutch pre-fill oil to maintain the target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, wherein the pre-fill oil maintenance target current is the current corresponding to the desired pressure of the clutch; When clutch pre-fill oil control activation is detected, the clutch is controlled to maintain the step maintenance time for the pre-fill oil step target current, and the clutch is controlled to maintain the target maintenance time for the pre-fill oil maintenance target current.

2. The method according to claim 1, characterized in that Determining a pre-fill oil step target current of the clutch according to the transmission oil temperature includes: Determining the pre-fill oil step target current according to the gearbox oil temperature and a first mapping relationship; The first mapping relationship is used to indicate the mapping relationship between the transmission oil temperature and the pre-fill oil step current.

3. The method according to claim 1, characterized in that Determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature includes: Determine the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening, the transmission oil temperature and a second mapping relationship; The second mapping relationship is used to indicate the mapping relationship between the accelerator pedal opening, the transmission oil temperature and the maintenance time of the pre-fill oil step target current.

4. The method according to any one of claims 1 to 3, characterized in that: After determining the step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the gearbox oil temperature, the method further includes: Get the accelerator pedal change rate; Determining a first duration correction factor according to the accelerator pedal change rate and a third mapping relationship, wherein the third mapping relationship is used to indicate a mapping relationship between the accelerator pedal change rate and the first duration correction factor; According to the first duration correction factor, the step maintenance duration of the pre-filling oil step target current is corrected to obtain a first corrected step maintenance duration, so that the pre-filling oil step target current maintains the first corrected step maintenance duration.

5. The method according to claim 4, characterized in that Also includes: When it is detected that the driver intends to exit the clutch engagement operation and the pre-filling oil control is activated again, if the time interval between the two pre-filling oil control activations is less than the preset time interval and the transmission oil temperature is greater than or equal to zero, determining the second duration correction factor according to the time interval between the two pre-filling oil control activations and the fourth mapping relationship; The fourth mapping relationship is used to indicate the mapping relationship between the time interval between two consecutive activations of the pre-filling oil control and the second duration correction factor; The second corrected step maintenance time is determined based on the first time correction factor, the second time correction factor and the step maintenance time of the pre-filling oil step target current, so that the pre-filling oil step target current maintains the second corrected step maintenance time during the re-pre-filling oil control process.

6. The method according to claim 5, characterized in that Determining a second corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-fill oil step target current includes: Determine a third corrected step maintenance time according to the first time correction factor, the second time correction factor and the step maintenance time of the pre-fill oil step target current; In the case where the third correction step maintenance time is greater than the maximum time among the set maintenance time of the pre-filling oil step target current, the maximum time among the maintenance time of the pre-filling oil step target current is determined as the second correction step maintenance time; When the third correction step maintaining time is less than or equal to the maximum time of the set pre-filling oil step target current maintaining time, the third correction step maintaining time is determined as the second correction step maintaining time.

7. The method according to claim 1, characterized in that Determining a target maintenance time for the pre-fill oil of the clutch to maintain a target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, including: Determining a target maintenance time for maintaining the target current of the pre-fill oil according to the transmission oil temperature, the speed difference between the front and rear ends of the clutch, and a fifth mapping relationship; The fifth mapping relationship is used to indicate the mapping relationship between the transmission oil temperature, the speed difference between the front and rear ends of the clutch, and the maintenance time of the pre-fill oil to maintain the target current.

8. The method according to claim 1 or 7, characterized in that: After determining the target maintenance time of the clutch pre-fill oil to maintain the target current according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, the method further includes: When the speed difference between the front and rear ends of the clutch is less than the preset speed difference, obtaining the actual speed of the generator for a preset number of consecutive cycles, and determining the generator speed variance according to the actual speed of the generator for the preset number of cycles; Determine a third duration correction factor according to the gearbox oil temperature, the generator speed variance and a sixth mapping relationship; the sixth mapping relationship is used to indicate a mapping relationship between the gearbox oil temperature, the generator speed variance and the third duration correction factor; According to the third time correction factor, the target maintenance time of the clutch pre-fill oil to maintain the target current is corrected to obtain a corrected maintenance time; According to the corrected maintenance time, a final maintenance time for the pre-fill oil of the clutch to maintain the target current is determined, so that the pre-fill oil maintains the target current for the final maintenance time.

9. The method according to claim 8, characterized in that Determining the final maintenance time of the clutch pre-fill oil to maintain the target current according to the corrected maintenance time includes: In the case where the corrected maintenance time is greater than the maximum time among the set maintenance time of the pre-filling oil to maintain the target current, the maximum time among the maintenance time of the pre-filling oil to maintain the target current is determined as the final maintenance time; When the corrected maintenance time is less than or equal to the maximum time among the set maintenance time of the pre-fill oil to maintain the target current, the corrected maintenance time is determined as the final maintenance time.

10. A clutch pre-fill oil control device, used when a hybrid vehicle switches between a series mode and a parallel mode, characterized in that: include: An acquisition module is configured to acquire the current transmission oil temperature, accelerator pedal opening, and clutch front and rear end speed difference of the vehicle; a first determination module, configured to determine a pre-fill oil step target current of the clutch according to the transmission oil temperature, and to determine a step maintenance time of the pre-fill oil step target current according to the accelerator pedal opening and the transmission oil temperature; A second determination module is configured to determine a target maintenance time for maintaining a target current of the clutch by pre-filling oil according to the transmission oil temperature and the speed difference between the front and rear ends of the clutch, wherein the pre-filling oil maintaining target current is a current corresponding to a desired pressure of the clutch; The control module is configured to control the clutch to maintain the step maintenance time for the pre-fill oil step target current and control the clutch to maintain the target maintenance time for the pre-fill oil maintenance target current when the clutch pre-fill oil control is detected to be activated.

Images