A control method and related device for clutch opening

Abstract

This application discloses a clutch disengagement control method and related apparatus. Based on the vehicle's operating conditions, a target disengagement speed threshold is obtained for the clutch to enter the disengagement control phase. This target disengagement speed threshold is determined based on the torque of a target object, which is a higher-priority object among multiple objects under operating conditions. These multiple objects include the engine and the clutch. If the speed of the target object is lower than the target disengagement speed threshold, the clutch is controlled to enter the disengagement control phase, which includes multiple disengagement sub-phases. During the disengagement control phase, based on the actual operating conditions of the engine and clutch, the clutch is controlled to enter the corresponding disengagement sub-phase, and coordinated control of the engine and clutch is performed during these sub-phases. This application achieves coordinated control of the clutch and engine, avoiding drivability issues, preventing stalling risks, and improving safety.

Description

Technical Field

[0001] This invention relates to the automotive field, and more particularly to a control method and related apparatus for clutch opening. Background Technology

[0002] An automatic transmission is a transmission device that can automatically shift gears based on vehicle speed and engine speed. Currently, there are four common types of automatic transmissions in automobiles: hydraulic automatic transmission (AT), continuously variable transmission (CVT), automated manual transmission (AMT), and dual-clutch transmission (DCT).

[0003] When an automatic transmission with a clutch is installed and matched with the engine, the clutch needs to be locked at higher vehicle speeds to improve transmission efficiency and reduce clutch slippage. During braking or coasting, to save fuel, the engine enters fuel cut-off control, meaning the engine reverse-drags the vehicle, giving it a certain amount of deceleration. However, when the engine speed falls below a threshold (e.g., slightly above idle speed), fuel supply needs to be restored to re-inject fuel and ignite to generate positive torque. At the same time, when the vehicle speed falls below a certain level, the clutch needs to be disengaged to prevent the engine from stalling.

[0004] However, engine control and automatic transmission control are controlled by two separate controllers, each with its own control objectives. Under braking conditions, there is a lack of direct coordination and control between them, which can easily cause drivability problems (such as impact, clunk noise, etc.), and in more serious cases, the risk of engine stalling, resulting in insufficient braking pressure (in models based on vacuum assist), thus creating certain safety risks. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a clutch opening control method and related device to achieve coordinated control of the clutch and engine, avoid drivability issues, prevent the risk of stalling, and improve safety.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] In a first aspect, embodiments of this application provide a control method for clutch disengagement, the method comprising:

[0008] Based on the vehicle's operating conditions, a target opening speed threshold is obtained for the clutch to enter the opening control phase. The target opening speed threshold is determined based on the torque of a target object, which is a higher priority object among multiple objects under the operating conditions. The multiple objects include the engine and the clutch.

[0009] If the rotational speed of the target object is lower than the target opening speed threshold, the clutch is controlled to enter the opening control phase, which includes multiple opening sub-phases.

[0010] During the opening control phase, the clutch is controlled to enter the corresponding opening sub-phase according to the actual operating conditions of the engine and the clutch, and the engine and the clutch are coordinated and controlled during the opening sub-phase.

[0011] In one possible implementation, obtaining the target opening speed threshold for the clutch to enter the opening control phase based on the vehicle's operating conditions includes:

[0012] If the operating condition is the first operating condition, obtain the engine's idle speed, clutch opening time, opening delay deviation, and speed change rate;

[0013] The target opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0014] In one possible implementation, obtaining the clutch opening time includes:

[0015] The basic opening rate of the clutch is determined based on the torque of the clutch, and the target object is the clutch;

[0016] Obtain the oil temperature correction of the clutch;

[0017] The clutch opening time is calculated based on the basic opening rate and the oil temperature correction.

[0018] In one possible implementation, calculating the target opening speed threshold based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate includes:

[0019] The initial opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0020] The target opening speed threshold is determined based on the initial opening speed threshold and the brake correction value.

[0021] In one possible implementation, obtaining the target opening speed threshold for the clutch to enter the opening control phase based on the vehicle's operating conditions includes:

[0022] If the vehicle is operating under the condition of emergency braking during coasting, the target opening speed threshold is determined based on the engine torque, and the target object is the engine.

[0023] In one possible implementation, the opening sub-stage is a pre-opening stage, and the coordinated control of the engine and the clutch in the opening sub-stage includes:

[0024] Calculate the load request of the clutch;

[0025] The torque of the engine is controlled according to the load request of the clutch;

[0026] The torque of the clutch is controlled based on the torque of the engine.

[0027] In one possible implementation, during the opening control phase, based on the actual operating conditions of the engine and the clutch, the clutch is controlled to enter a corresponding opening sub-phase, and coordinated control of the engine and the clutch is performed during the opening sub-phase, including:

[0028] If slippage is detected between the engine and the clutch, the clutch is controlled to enter the direct opening stage, which is the opening sub-stage.

[0029] Calculate the load request and idle speed request of the clutch;

[0030] The torque of the engine is controlled according to the load request and idle speed request of the clutch;

[0031] The opening rate of the clutch is controlled according to braking and deceleration.

[0032] In one possible implementation, during the opening control phase, based on the actual operating conditions of the engine and the clutch, the clutch is controlled to enter a corresponding opening sub-phase, and coordinated control of the engine and the clutch is performed during the opening sub-phase, including:

[0033] If the speed of the clutch is lower than a preset threshold, the clutch is controlled to enter the fully open stage, which is the opening sub-stage;

[0034] The clutch opening rate is controlled based on the engine speed and a target deviation, wherein the target deviation is the deviation between the engine idle speed and the engine speed;

[0035] When the clutch is engaged to the target position, the engine idle speed request control is disengaged.

[0036] Secondly, embodiments of this application provide a clutch disengagement control device, the device comprising:

[0037] The acquisition unit is used to acquire the target opening speed threshold for the clutch to enter the opening control stage according to the operating conditions of the vehicle. The target opening speed threshold is determined based on the torque of the target object, which is the object with higher priority among multiple objects under the operating conditions. The multiple objects include the engine and the clutch.

[0038] The control unit is configured to control the clutch to enter the opening control phase if the rotational speed of the target object is lower than the target opening speed threshold, the opening control phase including multiple opening sub-phases;

[0039] The control unit is further configured to, during the opening control phase, control the clutch to enter the corresponding opening sub-phase according to the actual operating conditions of the engine and the clutch, and to perform coordinated control of the engine and the clutch during the opening sub-phase.

[0040] In one possible implementation, the acquiring unit is specifically used for:

[0041] If the operating condition is the first operating condition, obtain the engine's idle speed, clutch opening time, opening delay deviation, and speed change rate;

[0042] The target opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0043] In one possible implementation, the acquiring unit is specifically used for:

[0044] The basic opening rate of the clutch is determined based on the torque of the clutch, and the target object is the clutch;

[0045] Obtain the oil temperature correction of the clutch;

[0046] The clutch opening time is calculated based on the basic opening rate and the oil temperature correction.

[0047] In one possible implementation, the acquiring unit is specifically used for:

[0048] The initial opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0049] The target opening speed threshold is determined based on the initial opening speed threshold and the brake correction value.

[0050] In one possible implementation, the acquiring unit is specifically used for:

[0051] If the vehicle is operating under the condition of emergency braking during coasting, the target opening speed threshold is determined based on the engine torque, and the target object is the engine.

[0052] In one possible implementation, the opening sub-stage is a pre-opening stage, and the control unit is specifically used for:

[0053] Calculate the load request of the clutch;

[0054] The torque of the engine is controlled according to the load request of the clutch;

[0055] The torque of the clutch is controlled based on the torque of the engine.

[0056] In one possible implementation, the control unit is specifically used for:

[0057] If slippage is detected between the engine and the clutch, the clutch is controlled to enter the direct opening stage, which is the opening sub-stage.

[0058] Calculate the load request and idle speed request of the clutch;

[0059] The torque of the engine is controlled according to the load request and idle speed request of the clutch;

[0060] The opening rate of the clutch is controlled according to braking and deceleration.

[0061] In one possible implementation, the control unit is specifically used for:

[0062] If the speed of the clutch is lower than a preset threshold, the clutch is controlled to enter the fully open stage, which is the opening sub-stage;

[0063] The clutch opening rate is controlled based on the engine speed and a target deviation, wherein the target deviation is the deviation between the engine idle speed and the engine speed;

[0064] When the clutch is engaged to the target position, the engine idle speed request control is disengaged.

[0065] Thirdly, embodiments of this application provide a control device for clutch opening, the device including a processor and a memory:

[0066] The memory is used to store program code and transmit the program code to the processor;

[0067] The processor is configured to execute any of the methods described in the first aspect according to the instructions in the program code.

[0068] Fourthly, embodiments of this application provide a vehicle on which the device described in any of the second aspects or the equipment described in the third aspect is installed.

[0069] As can be seen from the above technical solution, this application obtains the target opening speed threshold for the clutch to enter the opening control stage based on the vehicle's operating conditions. The target opening speed threshold is determined based on the torque of the target object, which is the object with higher priority among multiple objects under operating conditions. These multiple objects include the engine and the clutch. If the speed of the target object is lower than the target opening speed threshold, the clutch is controlled to enter the opening control stage, which includes multiple opening sub-stages. In the opening control stage, the clutch is controlled to enter the corresponding opening sub-stage based on the actual operating conditions of the engine and clutch, and coordinated control of the engine and clutch is performed in the opening sub-stage. Since the target opening speed threshold is determined based on the torque of the clutch or engine selected according to the operating conditions, and when entering the opening control stage, the actual operating conditions of the engine and clutch can be comprehensively considered to control the clutch to enter the corresponding opening sub-stage, and coordinated control of the engine and clutch is performed in the opening sub-stage, coordinated control of the clutch and engine is achieved, avoiding drivability issues, preventing stalling risks, and improving safety. Attached Figure Description

[0070] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0071] Figure 1 An example diagram illustrating the through-shaft noise and impact generated when the clutch of an AT, CVT, or DCT is opened, providing information for related technologies.

[0072] Figure 2 An example diagram illustrating the impact caused by engine torque recovery when the clutch of an AT, CVT, or DCT is not fully disengaged, providing information for related technologies.

[0073] Figure 3 A flowchart illustrating a clutch opening control method provided in this application embodiment;

[0074] Figure 4A schematic diagram illustrating clutch engagement provided in an embodiment of this application;

[0075] Figure 5 This is a structural diagram of a clutch opening control device provided in an embodiment of this application. Detailed Implementation

[0076] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0077] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0078] Current methods for clutch disengagement control lack direct coordination between the clutch and engine. This includes clutch disengagement control in AT and CVT transmissions, as well as clutch disengagement control in DCT transmissions. During emergency braking, if clutch disengagement is delayed, there is a risk of stalling. Alternatively, during disengagement, if the engine recovers from fuel cut-off and enters idle, and the clutch is not fully disengaged, the sudden torque change can cause shaft disturbance, resulting in impacts and gear knocking noises. Furthermore, if the engine speed drops below the clutch's operating speed during disengagement, and the vehicle speed decreases, the engine speed may exceed the shaft speed. If the driver then accelerates again when the engine speed drops, the engine speed may rise above the clutch speed, causing drag and impact. Similarly, during coasting, if the driver immediately applies the brakes when the engine speed is low, and the clutch disengagement is delayed, impacts and stalling are likely.

[0079] See Figure 1 and Figure 2 , Figure 1 Example diagrams are shown illustrating the through-shaft noise and impact generated when the clutch of an AT, CVT, or DCT is engaged. Figure 2 The diagram shows an example of an AT, CVT, or DCT where the clutch is not fully disengaged, causing a shock during engine torque recovery.

[0080] To address the aforementioned technical problems, this application provides a clutch disengagement control method. This method determines a target disengagement speed threshold based on the vehicle's operating conditions, where the target speed threshold is determined by the torque of a target object (including the engine and clutch) that has higher priority among multiple objects under operating conditions. If the speed of the target object is lower than the target disengagement speed threshold, the clutch is controlled to enter the disengagement control phase, which includes multiple disengagement sub-phases. During the disengagement control phase, the clutch is controlled to enter the corresponding disengagement sub-phase based on the actual operating conditions of the engine and clutch, and coordinated control of the engine and clutch is performed during these sub-phases. Because the target disengagement speed threshold is determined based on the torque of either the clutch or the engine under operating conditions, and the disengagement control phase integrates the actual operating conditions of the engine and clutch to control the clutch into the corresponding disengagement sub-phase, coordinated control of the engine and clutch is achieved, thus avoiding drivability issues, preventing stalling risks, and improving safety.

[0081] For ease of understanding, a clutch opening control method provided in this application embodiment will be described in detail below with reference to the accompanying drawings. The method provided in this application embodiment can be executed by a vehicle terminal.

[0082] See Figure 3 , Figure 3 A flowchart of a control method for clutch opening is shown, the method comprising:

[0083] S301. Based on the vehicle's operating conditions, obtain the target opening speed threshold for the clutch to enter the opening control phase. The target opening speed threshold is determined based on the torque of the target object. The target object is the object with higher priority among multiple objects under the operating conditions. The multiple objects include the engine and the clutch.

[0084] In the embodiments of this application, the clutch opening control can be divided into multiple stages. The first stage is the wait stage, which is mainly used to obtain the target opening speed threshold for the clutch to enter the opening control stage based on the operating conditions of the vehicle.

[0085] In this application embodiment, the method for obtaining the target opening speed threshold may differ depending on the operating conditions. In one possible implementation, if the operating condition is a first condition, which can be any condition other than sudden heavy braking during coasting (i.e., emergency braking during coasting), the method for obtaining the target opening speed threshold for the clutch entering the opening control phase may be to obtain the engine idle speed, clutch opening time, opening delay deviation, and speed change rate, and then calculate the target opening speed threshold based on the engine idle speed, clutch opening time, opening delay deviation, and speed change rate.

[0086] It should be noted that there are several ways to calculate the target opening speed threshold based on engine idle speed, clutch opening time, opening delay deviation, and speed change rate. One method is to calculate the target opening speed threshold solely based on engine idle speed, clutch opening time, opening delay deviation, and speed change rate. In this case, the formula for calculating the target opening speed threshold for the basic clutch entering the opening control phase can be:

[0087] N FnlOpenThrsh =N IdleSpd +Offset1-t OpenTime *a Clutch

[0088] Where, N FnlOpenThrsh Indicates the target opening speed threshold; N IdleSpd This refers to the engine's idle speed; Offset1 accounts for the delay in clutch engagement during engine fuel cut-off recovery, and is typically calibrated to 100 rpm; t OpenTime Indicates the clutch engagement time; a Clutch The clutch speed change rate can be used as a reference. When the speed change rate is less than 0, the value is taken as the value itself. When the speed change rate is greater than 0, it is considered to be 0.

[0089] In some cases, during the calculation of the target opening speed threshold, after acceleration filtering, if the accelerator is pressed and then the brake is applied, or if the brake is suddenly applied during coasting, the brake hydraulic system lags, resulting in a lag in the calculated deceleration. Therefore, additional compensation is needed based on the current braking force and deceleration. The target opening speed threshold is obtained by correcting the braking force using the output shaft deceleration and the brake. In this situation, another way to calculate the target opening speed threshold based on engine idle speed, clutch opening time, opening delay deviation, and speed change rate is to calculate an initial opening speed threshold based on these parameters, and then determine the target opening speed threshold based on the initial opening speed threshold and the brake correction value.

[0090] At this point, the calculation formula for the initial opening speed threshold is similar to that in the previous implementation method, and can be:

[0091] N RawOpenThrsh =N IdleSpd +Offset1-t OpenTime *a Clutch

[0092] Where, N RawOpenThrsh Indicates the initial opening speed threshold; N IdleSpd This refers to the engine's idle speed; Offset1 accounts for the delay in clutch engagement during engine fuel cut-off recovery, and is typically calibrated to 100 rpm; t OpenTime Indicates the clutch engagement time; a Clutch The clutch speed change rate can be used as a reference. When the speed change rate is less than 0, the value is taken as the value itself. When the speed change rate is greater than 0, it is considered to be 0.

[0093] The method for determining the target opening speed threshold based on the initial opening speed threshold and the brake correction value can be to correct the initial opening speed threshold using the brake correction, and then select the minimum value between the corrected result and the preset speed threshold as the target opening speed threshold. Specifically, correcting the initial opening speed threshold using the brake correction can be done by adding a brake correction to the initial opening speed threshold. The preset speed threshold can be the highest opening threshold calibrated through real-world vehicle experience; this highest opening threshold should not be too high, and is generally calibrated to 1800 rpm. In this case, the formula for calculating the target opening speed threshold can be:

[0094] N FnlOpenThrsh =Min((N) RawOpenThrsh +N BrkOfst ),1800)

[0095] Where, N FnlOpenThrsh Indicates the target opening speed threshold; N RawOpenThrsh N represents the initial opening speed threshold. BrkOfst This indicates braking correction; Min() indicates finding the minimum value.

[0096] It should be noted that the brake correction can be obtained by looking up a table based on the output shaft deceleration. The correspondence between the output shaft deceleration and the brake correction can be found in Table 1.

[0097] Table 1

[0098]

[0099] In one possible implementation, the method for obtaining the clutch opening time used in the aforementioned embodiments can be as follows: determine the basic opening rate of the clutch based on the clutch torque, where the target object is the clutch; obtain the clutch oil temperature correction; and then calculate the clutch opening time based on the basic opening rate and the oil temperature correction. The formula for calculating the clutch opening time can be:

[0100]

[0101] Among them, t OpenTime R is the clutch opening time. OpenRat K is the basic opening rate of the clutch. Temp For temperature correction.

[0102] The basic clutch opening rate can be determined by referring to Table 2 using the clutch torque, and the clutch oil temperature correction can be determined by referring to Table 3. Tables 2 and 3 are obtained from actual vehicle calibration, and are detailed below:

[0103] Table 2

[0104] clutch torque 0 10 20 30 50 100 Basic opening speed 0.2 0.2 0.3 0.4 0.5 1

[0105] Table 3

[0106] Oil temperature correction -30 -20 0 10 30 50 100 Delay time 1.5 1.3 1.1 1.1 1 0.9 0.8

[0107] In another possible implementation, if the vehicle is operating under the condition of emergency braking during coasting, the target opening speed threshold for the clutch to enter the opening control phase can be determined based on the engine torque, where the target object is the engine.

[0108] During emergency braking while coasting, to prevent the engine speed from approaching idle and the driver from suddenly applying the brakes, the clutch disengagement may be delayed, causing problems. This is because when the engine speed is below a threshold, clutch disengagement control will also be activated. In other words, the lower the engine's negative torque, the earlier the clutch disengagement control will be activated, controlling the increase in engine torque. Therefore, the engine torque determines the target disengagement speed threshold, which can be determined by referring to a table based on specific parameters. For different vehicle models and different types of transmissions, appropriate on-vehicle calibration adjustments can be made. Under one possible scenario, the relationship between engine torque and the target disengagement speed threshold can be seen in Table 4.

[0109] Table 4

[0110]

[0111]

[0112] S302. If the rotational speed of the target object is lower than the target opening speed threshold, the clutch is controlled to enter the opening control stage, which includes multiple opening sub-stages.

[0113] When the clutch speed is lower than the target opening speed threshold, the clutch opening control phase begins. Typically, the clutch opening control phase can include multiple opening sub-phases, such as the pre-opening phase, the direct opening phase, and the fully open phase.

[0114] S303. In the opening control phase, based on the actual operating conditions of the engine and the clutch, the clutch is controlled to enter the corresponding opening sub-phase, and the engine and the clutch are coordinated and controlled in the opening sub-phase.

[0115] If the opening sub-stage is a pre-opening stage, the coordinated control of the engine and clutch in the opening sub-stage can be achieved by calculating the clutch load request, controlling the engine torque based on the clutch load request, and then controlling the clutch torque based on the engine torque.

[0116] As can be seen, the pre-opening phase includes engine control and clutch control. During engine control, to prevent the engine speed from dropping below the shaft speed during clutch opening, a transmission load request needs to be sent to the engine. The engine controls its torque by referencing the transmission load, and then the clutch opens with reference to the engine torque; that is, the clutch torque is controlled based on the engine torque. The clutch load request can be calculated using the following formula:

[0117]

[0118] Among them, T T orqLo ad N is the load request sent by the transmission to the engine. Frz The engine speed is frozen to enter the clutch pre-opening control phase; N Eng N is the actual engine speed. Open Offset2 is the speed at which the clutch is expected to fully open, which is the engine idle speed plus Offset1. Offset1 needs to be higher than the engine torque to directly restore the controlled speed; generally, Offset1 is calibrated to 100 rpm. Offset2 takes into account the engine torque accuracy deviation. Generally, the error in the low torque range of an engine is ±5 Nm. To prevent the engine from becoming positive torque and causing vibration in the transmission shaft system due to the clutch not being fully open, the deviation is generally reduced, i.e., Offset2 is -5 Nm. Clc hTo rq T represents the clutch torque of the transmission. EngFrzThe torque of the engine is used; the calculated gearbox load must not exceed the torque of the clutch itself.

[0119] Because hydraulic pressure relief has a hysteresis, N Est This is the estimated engine speed at which the clutch is fully engaged.

[0120] in:

[0121] N Est =N Eng +a Clutch *T Delay

[0122] a Clutch =Min(a) Clutch ,0)

[0123] Among them, T Delay This refers to the depressurization time, which is related to oil temperature (this may vary between different systems and needs to be determined through analysis and summarization using real vehicle data or bench tests). Clutch The rate of change of clutch speed and the relationship between depressurization time and oil temperature can be found in Table 5.

[0124] Table 5

[0125] oil temperature -30 -20 0 10 30 50 100 Decompression time 0.2 0.2 0.15 0.15 0.1 0.1 0.1

[0126] Clutch control is based on engine torque to achieve coordinated control of the engine and clutch. In this case, clutch torque = Abs(engine torque), where Abs() represents the absolute value function.

[0127] In another possible implementation, during the opening control phase, the clutch is controlled to enter the corresponding opening sub-phase based on the actual operating conditions of the engine and clutch. The coordinated control of the engine and clutch during this sub-phase can also be achieved by controlling the clutch to enter a direct opening phase if slippage is detected. In this case, the direct opening phase is the opening sub-phase. During the direct opening phase, the coordinated control of the engine and clutch can be achieved by calculating the clutch's load and idle speed requests, controlling the engine torque based on these requests, and controlling the clutch opening rate based on braking and deceleration.

[0128] It should be noted that if slippage is detected between the engine and clutch, the system will proceed to the direct disengagement stage. There are three main criteria for slippage detection:

[0129] The speed difference (i.e., the difference between the engine speed and the clutch speed) is greater than the threshold (generally 50 rpm according to the actual vehicle calibration);

[0130] The speed difference must be greater than the threshold (10 rpm) for a continuous period of time (e.g., 0.1 s);

[0131] The engine torque is greater than the threshold; the threshold can be -3 Nm through actual vehicle calibration.

[0132] If any of the above conditions are met, the clutch will directly enter the direct disengagement stage.

[0133] During the direct start-up phase, engine control can be achieved by sending both load requests and idle speed requests to the engine. The idle speed request is equal to the engine speed plus a deviation correction (typically 30-50 rpm according to actual vehicle calibration).

[0134] The clutch can be controlled as follows: In this case, the clutch no longer references the engine torque but opens directly. The clutch opening rate is related to braking and deceleration; the greater the braking force, the faster the clutch opens; the greater the deceleration, the faster the clutch opens. The clutch cannot be fully opened to the KS point (KS point corresponds to 0 Nm) to prevent the driver from releasing the brake and pressing the accelerator again. A shallow clutch opening can easily cause a shock; therefore, the lower limit of opening is 3-5 Nm. For light braking, it's 5 Nm; for heavy braking, it's 3 Nm. If it's between light and heavy braking, it's calculated through interpolation.

[0135] In another possible implementation, during the opening control phase, based on the actual operating conditions of the engine and clutch, the clutch is controlled to enter the corresponding opening sub-phase. Coordinated control of the engine and clutch during the opening sub-phase can be achieved by controlling the clutch to enter a fully open phase if the clutch speed is below a preset threshold; the fully open phase is the opening sub-phase. In this case, the coordinated control of the engine and clutch can be achieved by controlling the clutch opening rate based on the engine speed and a target deviation, where the target deviation is the difference between the engine's idle speed and its engine speed. When the clutch opens to the target position, the engine idle speed request control is disengaged.

[0136] Specifically, when the clutch speed is below a threshold (generally set at 200 rpm according to the actual vehicle calibration), that is... Figure 4 If the fully open threshold is reached, the clutch will directly open to the clutch half-engagement point (0 Nm). The opening rate is based on the engine speed and the target deviation, which is the difference between the engine idle speed and the engine speed. At this point, the higher the engine speed, the slower the opening; the higher the engine speed, the slower the opening; and the lower the engine speed, the faster the opening. When the clutch opens to point KS, the engine idle speed request control is discontinued, and a load of 0 Nm is sent to the engine.

[0137] It should be noted that, based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods.

[0138] based on Figure 3 The corresponding embodiment provides a clutch opening control method, and the embodiments of this application provide a clutch opening control device. See also Figure 5 The device includes:

[0139] The acquisition unit 501 is used to acquire a target opening speed threshold for the clutch to enter the opening control stage according to the operating conditions of the vehicle. The target opening speed threshold is determined based on the torque of a target object. The target object is an object with higher priority among multiple objects under the operating conditions. The multiple objects include the engine and the clutch.

[0140] Control unit 502 is used to control the clutch to enter the opening control stage if the rotational speed of the target object is lower than the target opening speed threshold, the opening control stage including multiple opening sub-stages;

[0141] The control unit 502 is further configured to, during the opening control phase, control the clutch to enter the corresponding opening sub-phase according to the actual operating conditions of the engine and the clutch, and to perform coordinated control of the engine and the clutch during the opening sub-phase.

[0142] In one possible implementation, the acquiring unit is specifically used for:

[0143] If the operating condition is the first operating condition, obtain the engine's idle speed, clutch opening time, opening delay deviation, and speed change rate;

[0144] The target opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0145] In one possible implementation, the acquiring unit is specifically used for:

[0146] The basic opening rate of the clutch is determined based on the torque of the clutch, and the target object is the clutch;

[0147] Obtain the oil temperature correction of the clutch;

[0148] The clutch opening time is calculated based on the basic opening rate and the oil temperature correction.

[0149] In one possible implementation, the acquiring unit is specifically used for:

[0150] The initial opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

[0151] The target opening speed threshold is determined based on the initial opening speed threshold and the brake correction value.

[0152] In one possible implementation, the acquiring unit is specifically used for:

[0153] If the vehicle is operating under the condition of emergency braking during coasting, the target opening speed threshold is determined based on the engine torque, and the target object is the engine.

[0154] In one possible implementation, the opening sub-stage is a pre-opening stage, and the control unit is specifically used for:

[0155] Calculate the load request of the clutch;

[0156] The torque of the engine is controlled according to the load request of the clutch;

[0157] The torque of the clutch is controlled based on the torque of the engine.

[0158] In one possible implementation, the control unit is specifically used for:

[0159] If slippage is detected between the engine and the clutch, the clutch is controlled to enter the direct opening stage, which is the opening sub-stage.

[0160] Calculate the load request and idle speed request of the clutch;

[0161] The torque of the engine is controlled according to the load request and idle speed request of the clutch;

[0162] The opening rate of the clutch is controlled according to braking and deceleration.

[0163] In one possible implementation, the control unit is specifically used for:

[0164] If the speed of the clutch is lower than a preset threshold, the clutch is controlled to enter the fully open stage, which is the opening sub-stage;

[0165] The clutch opening rate is controlled based on the engine speed and a target deviation, wherein the target deviation is the deviation between the engine idle speed and the engine speed;

[0166] When the clutch is engaged to the target position, the engine idle speed request control is disengaged.

[0167] As can be seen from the above technical solution, this application obtains the target opening speed threshold for the clutch to enter the opening control stage based on the vehicle's operating conditions. The target opening speed threshold is determined based on the torque of the target object, which is the object with higher priority among multiple objects under operating conditions. These multiple objects include the engine and the clutch. If the speed of the target object is lower than the target opening speed threshold, the clutch is controlled to enter the opening control stage, which includes multiple opening sub-stages. In the opening control stage, the clutch is controlled to enter the corresponding opening sub-stage based on the actual operating conditions of the engine and clutch, and coordinated control of the engine and clutch is performed in the opening sub-stage. Since the target opening speed threshold is determined based on the torque of the clutch or engine selected according to the operating conditions, and when entering the opening control stage, the actual operating conditions of the engine and clutch can be comprehensively considered to control the clutch to enter the corresponding opening sub-stage, and coordinated control of the engine and clutch is performed in the opening sub-stage, coordinated control of the clutch and engine is achieved, avoiding drivability issues, preventing stalling risks, and improving safety.

[0168] This application provides a clutch opening control device, the device including a processor and a memory:

[0169] The memory is used to store program code and transmit the program code to the processor;

[0170] The processor is used to execute the methods described in the foregoing embodiments according to the instructions in the program code.

[0171] This application also provides a vehicle, which is equipped with the device or equipment described in the foregoing embodiments.

[0172] The descriptions of the processes or structures corresponding to the above-mentioned figures each have their own emphasis. For parts of a process or structure that are not described in detail, please refer to the relevant descriptions of other processes or structures.

[0173] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium can be at least one of the following media: read-only memory (ROM), RAM, magnetic disk, or optical disk, etc., and other media capable of storing program code.

[0174] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0175] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method for clutch disengagement, characterized in that, The method includes: Based on the vehicle's operating conditions, a target opening speed threshold is obtained for the clutch to enter the opening control phase. The target opening speed threshold is determined based on the torque of a target object, which is a higher priority object among multiple objects under the operating conditions. The multiple objects include the engine and the clutch. If the rotational speed of the target object is lower than the target opening speed threshold, the clutch is controlled to enter the opening control phase, which includes multiple opening sub-phases. During the opening control phase, the clutch is controlled to enter the corresponding opening sub-phase according to the actual operating conditions of the engine and the clutch, and the engine and the clutch are coordinated and controlled during the opening sub-phase. In the opening control phase, based on the actual operating conditions of the engine and the clutch, the clutch is controlled to enter the corresponding opening sub-phase, and coordinated control of the engine and the clutch is performed in the opening sub-phase, including: If slippage is detected between the engine and the clutch, the clutch is controlled to enter the direct opening stage, which is the opening sub-stage. Calculate the load request and idle speed request of the clutch; The torque of the engine is controlled according to the load request and idle speed request of the clutch; The opening rate of the clutch is controlled according to braking and deceleration; If the speed of the clutch is lower than a preset threshold, the clutch is controlled to enter the fully open stage, which is the opening sub-stage; The clutch opening rate is controlled based on the engine speed and a target deviation, wherein the target deviation is the deviation between the engine idle speed and the engine speed; When the clutch is engaged to the target position, the engine idle speed request control is disengaged.

2. The method according to claim 1, characterized in that, The step of obtaining the target opening speed threshold for the clutch to enter the opening control phase based on the vehicle's operating conditions includes: If the operating condition is the first operating condition, the engine idle speed, clutch opening time, opening delay deviation and speed change rate are obtained. The first operating condition is any operating condition other than the emergency braking condition during coasting. The target opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate.

3. The method according to claim 2, characterized in that, Obtaining the clutch opening time includes: The basic opening rate of the clutch is determined based on the torque of the clutch, and the target object is the clutch; Obtain the oil temperature correction of the clutch; The clutch opening time is calculated based on the basic opening rate and the oil temperature correction.

4. The method according to claim 2, characterized in that, The step of calculating the target opening speed threshold based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate includes: The initial opening speed threshold is calculated based on the engine idle speed, the clutch opening time, the opening delay deviation, and the speed change rate. The target opening speed threshold is determined based on the initial opening speed threshold and the brake correction value.

5. The method according to claim 1, characterized in that, The step of obtaining the target opening speed threshold for the clutch to enter the opening control phase based on the vehicle's operating conditions includes: If the vehicle is operating under the condition of emergency braking during coasting, the target opening speed threshold is determined based on the engine torque, and the target object is the engine.

6. The method according to any one of claims 1-5, characterized in that, The opening sub-stage is a pre-opening stage, and the coordinated control of the engine and the clutch in the opening sub-stage includes: Calculate the load request of the clutch; The torque of the engine is controlled according to the load request of the clutch; The torque of the clutch is controlled based on the torque of the engine.

7. A control device for clutch disengagement, characterized in that, The device includes: The acquisition unit is used to acquire the target opening speed threshold for the clutch to enter the opening control stage according to the operating conditions of the vehicle. The target opening speed threshold is determined based on the torque of the target object, which is the object with higher priority among multiple objects under the operating conditions. The multiple objects include the engine and the clutch. The control unit is configured to control the clutch to enter the opening control phase if the rotational speed of the target object is lower than the target opening speed threshold, the opening control phase including multiple opening sub-phases; The control unit is also configured to, during the opening control phase, control the clutch to enter the corresponding opening sub-phase according to the actual operating conditions of the engine and the clutch, and to perform coordinated control of the engine and the clutch during the opening sub-phase; The control unit is specifically used for: If slippage is detected between the engine and the clutch, the clutch is controlled to enter the direct opening stage, which is the opening sub-stage. Calculate the load request and idle speed request of the clutch; The torque of the engine is controlled according to the load request and idle speed request of the clutch; The opening rate of the clutch is controlled according to braking and deceleration; If the speed of the clutch is lower than a preset threshold, the clutch is controlled to enter the fully open stage, which is the opening sub-stage; The clutch opening rate is controlled based on the engine speed and a target deviation, wherein the target deviation is the deviation between the engine idle speed and the engine speed; When the clutch is engaged to the target position, the engine idle speed request control is disengaged.

8. A vehicle, characterized in that, The vehicle is equipped with the device as described in claim 7.

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