Control method and system for hydraulic torque converter, and computer-readable storage medium

Abstract

The present invention provides a control method and system for a torque converter, and a computer-readable storage medium. When the pump wheel speed passes through the torque converter coupling point, a segmented control strategy combining a speed regulation stage and a torque regulation stage is implemented. This can effectively improve the turbine speed oscillation and impact problems at the torque converter coupling point and enhance the driver's driving experience.

Description

Technical Field

[0001] The present invention relates to the field of automobile control technology, and in particular to a control method and system for a hydraulic torque converter, and a computer-readable storage medium. Background Art

[0002] Please refer to Figure 1 and Figure 2 The torque converter 2 in a car is a hydraulic component, which is usually composed of a housing 21, a lock-up clutch 22, a turbine 23, a guide wheel 24 and a pump wheel 25. It is generally installed between the engine 1 and the car's transmission 3, and the pump wheel 25 is connected to the rotating shaft of the engine 1, and the turbine 23 is connected to the transmission 3. It uses hydraulic oil as the working medium and plays the role of transmitting torque, changing torque, changing speed and clutching.

[0003] At the coupling point of the torque converter 2, the speed of the pump wheel 25 of the torque converter 2 (i.e., the engine speed) crosses the speed of the turbine 23, which often causes the speed of the turbine 23 to oscillate or shake, thereby causing an uncomfortable driving experience and being complained by the driver. Figure 3 shown.

[0004] The traditional solution to this problem is to reduce engine torque during impeller speed crossover to mitigate the impact on the turbine and improve the unpleasant driving experience when crossing the torque converter coupling point. While this method improves the impact on the torque converter coupling point, it also has the following shortcomings:

[0005] 1) The target torque for torque reduction at the torque converter coupling point (i.e., the gearbox coupling point) is the zero torque point on the pump side, such as Figure 4 As shown, since the actual resistance of the impeller from the turbine end is difficult to determine accurately, it is also difficult to determine the zero torque point accurately, which will affect the actual control effect of this method and the coverage of this method for different vehicle models and different working conditions of various vehicle models.

[0006] 2) The torque reduction process is often achieved by delaying the engine ignition angle, and the torque reduction amplitude is often large, which causes the ignition angle to be delayed significantly for a long time. Delaying the ignition angle significantly for a long time is not only not conducive to economy, but also not conducive to the stability of engine combustion, especially under low engine temperature and cold engine conditions. Once the engine has poor combustion, it is easy to cause the torque converter coupling point impact problem to be further aggravated.

[0007] 3) The torque recovery process after torque reduction takes a long time, which is not conducive to power output and affects acceleration performance.

[0008] 4) Only the working condition where the pump wheel speed crosses the turbine speed upward is considered, and the situation where the pump wheel crosses the turbine speed downward, which also has the impact problem, is not considered. Summary of the Invention

[0009] The object of the present invention is to provide a control method and system for a torque converter, and a computer-readable storage medium, which can ensure the acceleration or deceleration performance requirements of the vehicle while allowing the pump wheel speed to smoothly pass through the torque converter coupling point upward or downward, effectively improving the turbine speed oscillation and impact problems at the torque converter coupling point, and enhancing the driver's driving experience.

[0010] To achieve the above objectives, the present invention provides a control method for a hydraulic torque converter having a pump connected to an engine and a turbine connected to a transmission. The control method is used to achieve a process in which the pump speed crosses the turbine speed, and includes:

[0011] In the speed regulation stage, a target impeller speed is determined and the engine output torque is adjusted until the impeller speed reaches or exceeds the target impeller speed, where the target impeller speed is the current turbine speed or the sum of the current turbine speed and a pre-calibrated speed parameter.

[0012] The torque regulation phase is triggered after the impeller speed reaches or exceeds the target impeller speed, and the output torque of the engine is regulated with a preset torque gradient until the output torque of the engine reaches the required target torque.

[0013] Optionally, in an accelerator pedal-operated condition, before the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed; the speed adjustment stage further includes:

[0014] In the first speed adjustment stage, the engine output torque is adjusted with the current turbine speed as the target pump speed until the pump speed reaches or exceeds the current turbine speed.

[0015] The second speed regulation stage is triggered after the impeller speed reaches or exceeds the current turbine speed, and the target impeller speed is the sum of the current turbine speed and the pre-calibrated speed parameter, and the output torque of the engine is continued to be adjusted until the impeller speed reaches or exceeds the sum.

[0016] Optionally, under the accelerator pedal working condition, the output torque T of the engine in the speed regulation stage is des =MN(T drv ,T dessyn ), and / or, the output torque T of the engine during the torque adjustment phase des =MN(T drv ,T desold +Tgrad );

[0017] Among them, MN() is the minimum function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine torque value required at the end of the speed regulation phase, T grad is the engine torque gradient value.

[0018] Optionally, under the throttle release condition, before the impeller speed crosses the turbine speed, the impeller speed is higher than the current turbine speed; in the speed adjustment stage, the difference between the current turbine speed and a pre-calibrated speed parameter is used as the target impeller speed, and the output torque of the engine is adjusted until the impeller speed reaches or is lower than the difference.

[0019] Optionally, under the throttle release condition, the engine output torque T in the speed regulation stage is des =MX(T drv ,T dessyn ), and / or, the output torque T of the engine during the torque adjustment phase des =MX(T drv ,T desold -T grad );

[0020] Among them, MX() is the maximum value function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

[0021] Optionally, the torque adjustment stage also requires the engine's gas path torque T lead Adjust the engine's gas path torque T lead =T des +T(N pump ,mifa), where T lead Indicates the gas circuit torque required by the engine clutch end, N pump represents the actual pump wheel speed, mifa represents the driver's required torque, T(N pump ,mifa) is obtained by pre-calibration.

[0022] Based on the same inventive concept, the present invention further provides a control system for a hydraulic torque converter, the hydraulic torque converter having a pump connected to an engine and a turbine connected to a transmission, the control system being configured to achieve a process in which the pump speed crosses the turbine speed, and comprising:

[0023] a speed regulating module, configured to determine a target impeller speed and regulate the engine output torque until the impeller speed reaches or exceeds the target impeller speed, wherein the target impeller speed is the current turbine speed or the sum of the current turbine speed and a pre-calibrated speed parameter;

[0024] The torque regulation module is configured to be triggered after the impeller speed reaches or exceeds the target impeller speed, and to regulate the output torque of the engine with a preset torque gradient until the output torque of the engine reaches the required target torque.

[0025] Optionally, in an accelerator pedal-operated condition, before the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed; the speed regulating module is further configured to:

[0026] First, the current turbine speed is used as the target pump speed, and the engine output torque is adjusted until the pump speed reaches or exceeds the current turbine speed;

[0027] After the impeller speed reaches or exceeds the current turbine speed, the sum of the current turbine speed and the pre-calibrated speed parameter is used as the target impeller speed, and the output torque of the engine is continuously adjusted until the impeller speed reaches or exceeds the sum.

[0028] Optionally, under the accelerator pedal working condition, the speed regulating module regulates the output torque T of the engine. des =MN(T drv ,T dessyn ), and / or, the output torque T of the engine adjusted by the torque adjustment module des =MN(T drv ,T desold +T grad );

[0029] Among them, MN() is the minimum function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the second speed regulation stage, T grad is the engine torque gradient value.

[0030] Optionally, under the throttle release condition, before the impeller speed crosses the turbine speed, the impeller speed is higher than the current turbine speed; the speed regulation module is used to use the difference between the current turbine speed and a pre-calibrated speed parameter as the target impeller speed, and adjust the output torque of the engine until the impeller speed reaches or is lower than the difference.

[0031] Optionally, under the throttle release condition, the speed regulation module regulates the engine output torque T des =MX(T drv ,T dessyn ), and / or, the output torque T of the engine adjusted by the torque adjustment module des =MX(T drv ,T desold -T grad );

[0032] Among them, MX() is the maximum value function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

[0033] Optionally, the torque adjustment module is also used to adjust the engine's gas path torque T lead Adjust the engine's gas path torque T lead =T des +T(N pump ,mifa), where T lead Indicates the gas circuit torque required by the engine clutch end, N pump represents the actual pump wheel speed, mifa represents the driver's required torque, T(N pump ,mifa) is obtained by pre-calibration.

[0034] The control system also includes a state machine, which has seven states: initialization, standby, throttle speed adjustment I, throttle speed adjustment II, throttle torque adjustment, throttle release speed adjustment, and throttle release torque adjustment. The state machine jumps to another state based on the throttle opening, pump wheel speed, engine required torque, and whether the lockup clutch of the torque converter is in the open state.

[0035] Based on the same inventive concept, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the control method of the torque converter as described in the present invention.

[0036] Compared with the prior art, the technical solution of the present invention has at least one of the following beneficial effects:

[0037] 1) When the pump speed crosses the turbine speed, segmented control is performed, first the speed regulation stage and then the torque regulation stage. This can effectively improve the turbine speed oscillation and impact problems at the torque converter coupling point and enhance the driver's driving experience.

[0038] 2) During the speed regulation stage, a closed-loop control algorithm based on the target impeller speed is adopted to avoid the problem of poor control effect caused by inaccurate torque line at the impeller end, and improve the accuracy, stability and smoothness of the impeller speed crossing process control.

[0039] 3) The torque gradient control method is adopted in the torque adjustment stage, which is beneficial to power output and can avoid the problem of long torque recovery process affecting acceleration or deceleration performance, and can effectively take into account the needs of power and comfort.

[0040] 4) The entire control process can coordinately control the engine's fire path demand and gas path demand torque, avoiding the problem of long-term and significant delay of the ignition angle caused by reducing the engine torque by only delaying the engine ignition angle (i.e., only through fire path control in the existing technology), thereby improving the stability of the engine's operation under low temperature and cold engine conditions.

[0041] 5) The method also considers the situations where the pump speed crosses the turbine speed (corresponding to the accelerator pedal-on condition) and the pump speed crosses the turbine speed (corresponding to the accelerator pedal-off condition), effectively expanding the applicable operating range of the method and comprehensively improving the driving experience at the torque converter coupling point. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the installation of a torque converter in a vehicle.

[0043] Figure 2 It is a structural diagram of the torque converter.

[0044] Figure 3 This is a schematic diagram of the turbine speed jitter caused by the pump impeller speed crossing the turbine speed.

[0045] Figure 4 This is a schematic diagram of torque reduction at the coupling point of a torque converter in the prior art.

[0046] Figure 5 It is a schematic diagram of the adjustment process of the control method of the torque converter according to a specific embodiment of the present invention when the accelerator is pressed.

[0047] Figure 6It is a schematic diagram of the adjustment process of the control method of the torque converter according to a specific embodiment of the present invention when the throttle is released.

[0048] Figure 7 It is a schematic diagram of the state machine conversion in the control system of the torque converter according to a specific embodiment of the present invention.

[0049] Figure 8 This is the triggering process of the control method for the torque converter according to the specific embodiment of the present invention. DETAILED DESCRIPTION

[0050] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present invention. It should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. Although terms such as first and second may be used to describe various elements, components, steps, and / or parts, these elements, components, steps, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, or part from another. Thus, a first element, component, step, or part discussed below may be referred to as a second element, component, step, or part without departing from the teachings of the present invention. When used herein, the singular forms "a," "an," and "said / the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "comprising" is used to identify the presence of certain features, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups. As used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0051] The technical solutions proposed by the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in a very simplified form and are not to exact scale, and are only used to facilitate and clearly illustrate the embodiments of the present invention.

[0052] An embodiment of the present invention provides a method for controlling a hydraulic torque converter. Figure 1 and Figure 2The torque converter 2 is composed of a housing 21, a lockup clutch 22, a turbine 23, a guide wheel 24, and a pump 25. It is installed between the engine 1 and the vehicle's transmission 3, with the pump 25 connected to the rotating shaft of the engine 1 and the turbine 23 connected to the transmission 3. At the coupling point of the torque converter 2, the speed of the pump 25 of the torque converter 2 (i.e., the engine speed) crosses the speed of the turbine 23. The control method of the torque converter of this embodiment is used to achieve the process of the pump speed crossing the turbine speed. It adopts a torque converter coupling point crossing working condition segmented control strategy, dividing the pump speed crossing the torque converter coupling point into two stages: a speed regulation stage and a torque regulation stage, as follows:

[0053] In the speed regulation phase, a target impeller speed is determined and the engine output torque is adjusted until the impeller speed reaches or exceeds the target impeller speed, where the target impeller speed is the current turbine speed or the sum of the current turbine speed and a pre-calibrated speed parameter.

[0054] The torque regulation phase is triggered after the impeller speed reaches or exceeds the target impeller speed, and the output torque of the engine is regulated with a preset torque gradient until the output torque of the engine reaches the required target torque.

[0055] The control method of this embodiment will be described in detail below using the accelerator pedal-pressing condition and the accelerator-releasing condition as two specific application examples of this embodiment.

[0056] Example 1: Accelerator pedal operation

[0057] During the throttle-on condition, if the impeller speed (engine speed) is lower than the turbine speed, the engine's final output torque is adjusted through two stages: speed regulation and torque regulation. In this example, the speed regulation stage aims to smoothly cross the turbine speed by adjusting the engine output torque, using the impeller speed as the control target (i.e., controlling the impeller speed by controlling the engine's target torque), to avoid excessive torque during the crossover process, which could cause turbine speed fluctuations. The torque regulation stage restores the engine's torque output to the driver's desired level using a specific torque gradient. This stage aims to avoid the overly strong impact caused by a rapid increase in engine torque, while simultaneously restoring engine torque output as quickly as possible to maintain the vehicle's dynamic performance during the throttle-on condition.

[0058] Please refer to Figure 5 The speed regulation phase of this example can be divided into two stages:

[0059] The first speed regulation stage I in which the pump wheel speed is lower than the turbine speed is based on the current turbine speed N turb is the target pump impeller speed N sol, adjusting the output torque of the engine until the pump impeller speed reaches or exceeds the current turbine speed;

[0060] The second speed control phase II is triggered after the pump wheel speed reaches or exceeds the current turbine speed and is controlled by the current turbine speed N turb The sum of the pre-calibrated speed parameter ofsa (i.e. N turb +ofsa) is the target pump impeller speed N sol , continue to adjust the engine output torque until the pump wheel speed reaches or exceeds the sum value N turb +ofsa, where ofsa needs to be calibrated through actual performance.

[0061] In addition, when the pump speed exceeds N turb After +ofsa, it will enter the torque adjustment stage.

[0062] In this example, in the first speed regulation stage and the second speed regulation stage, the output torque of the engine can be calculated by the following formula (1):

[0063] T des =MN(T drv ,T dessyn )……(1).

[0064] Among them, T des is the output torque of the engine, MN() is the minimum function, T drv is the driver's required torque, T dessyn Indicates the target torque value related to the pump speed regulation. dessyn It can be calculated using the known pump wheel speed regulation model. For example, the following pump wheel speed regulation model is used to calculate T dessyn :

[0065]

[0066] T desinertia =J*f(N diff ,N actual )……(3);

[0067] T dessyn =T Lossact +T desinertia ……(4);

[0068] In formulas (2)-(4), T Lossact Indicates the resistance torque at the engine clutch end, T Clutch T represents the actual torque value at the clutch end of the engine, J represents the engine's moment of inertia, n represents the pump wheel speed, and dn / dt represents the pump wheel's angular acceleration.desinertia Indicates the target acceleration torque of the pump wheel, N diff Indicates the target pump impeller speed N sol and the actual pump impeller speed N pump The difference, N pump Indicates the current actual pump wheel speed, f(N diff ,N pump ) represents the target angular acceleration under different speed differences and actual pump speed, f(N diff ,N pump ) is obtained by pre-calibration.

[0069] It should be understood that T dessyn In addition to using the impeller speed regulation model in the above example for calculation, other closed-loop control algorithms such as the classic PID (Proportional-Integral-Differential) can also be used for calculation.

[0070] In the torque regulation stage, the engine output torque T des It is calculated by the following formula (5):

[0071] T des =MN(T drv ,T desold +T grad )……(5);

[0072] Among them, MN() is the minimum function, T desold is the engine torque value required at the previous moment. The initial value of this value is the engine torque value required at the end of the speed regulation phase. grad is the engine torque gradient value, which is obtained through calibration based on actual performance. This value implements a linear fixed torque gradient control method in the torque regulation stage.

[0073] It should be understood that T grad It can also be other non-fixed torque gradients, which can implement a function curve variable torque gradient control method in the torque adjustment stage, or implement other non-function variable torque gradient control methods in the torque adjustment stage. The technical solution of the present invention does not make specific limitations on this, as long as the required adjustment effect can be achieved.

[0074] In addition, it should be noted that the control method of this example also needs to avoid the problem of excessive delay of the ignition angle during the adjustment process during the torque control adjustment stage. Therefore, the engine gas path torque T is required during the torque control adjustment stage. lead Adjust the engine's gas path torque T lead It is calculated by the following formula (6):

[0075] T lead =T des +T(N pump ,mifa)……(6);

[0076] In formula (6), T lead Indicates the gas circuit torque required by the engine clutch end, N pump Indicates the current actual pump wheel speed, mifa indicates the torque value required by the driver, T(N pump ,mifa) is obtained by pre-calibration.

[0077] Example 2: Release the throttle

[0078] Under the throttle-release condition, if the impeller speed is higher than the turbine speed, the engine's final output torque will be adjusted through two stages, speed regulation and torque regulation. The speed regulation stage takes adjusting the impeller speed as the control target, and controls the engine output torque to ensure that the impeller speed smoothly passes through the engine turbine speed, avoiding the problem of turbine speed oscillation caused by the impeller speed dropping too fast in the process. In the torque regulation stage, the torque value of the speed regulation stage is exited with a certain torque gradient until the driver's required torque is reached. The purpose of this stage is to avoid excessive impact caused by the engine torque dropping too fast, and to reduce the engine torque output as quickly as possible to ensure that the throttle-release condition meets the driver's expected reasonable deceleration feeling.

[0079] Specifically, in this example, please refer to Figure 6 , in the speed regulation stage, the current turbine speed N turb The difference between the pre-calibrated speed parameter ofsb (i.e. N turb -ofsb) is the target pump impeller speed N sol , adjust the engine output torque until the pump wheel speed reaches or is less than the difference N turb -ofsb, where ofsb needs to be calibrated according to actual performance and can be the same or different from ofsa. And when the pump wheel speed reaches or falls below N turb After the difference between 0 and ofsb is determined, the torque adjustment stage begins.

[0080] In this example, the target engine torque during the speed regulation phase can be calculated using the following formula (7):

[0081] T des =MX(T drv ,T dessyn )……(7);

[0082] Engine output torque T during torque regulation des It is calculated by the following formula (8).

[0083] T des =MX(T drv ,T desold -T grad )……(8);

[0084] Among them, T in formula (7) dessyn It can be obtained by the calculation method in Example 1. MX() is the maximum value function, T drv is the driver's required torque, T desold is the engine torque value required at the previous moment. The initial value of this value is the engine torque value required at the end of the speed regulation phase. grad is the engine torque gradient value, which is obtained through calibration based on actual performance, and the calibration method adopts the method in Example 1.

[0085] Under the throttle release condition, the torque control adjustment stage also needs to improve the torque control adjustment response speed of the torque converter coupling point. Therefore, the engine gas path torque T is required during the torque control adjustment stage. lead Adjust the engine's gas path torque T lead It can also be calculated by the above formula (6), where N pump , mifa and T(N pump ,mifa) values ​​may be different from those under the accelerator pedal condition.

[0086] Based on the same inventive concept, this embodiment further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it implements the control method of the torque converter as described in various embodiments of the present invention.

[0087] Furthermore, the computer-readable storage medium may be any medium capable of containing, storing, conveying, disseminating, or transmitting a computer program. For example, the storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium, with specific examples including: a magnetic storage device, such as a magnetic tape or a hard disk drive (HDD); an optical storage device, such as a compact disc (CDROM); a memory, such as a random access memory (RAM) or flash memory; and / or a wired or wireless communication link.

[0088] Based on the same invention concept, please combine Figures 5 and 6 This embodiment also provides a control system for a torque converter, which can implement the above-mentioned control method for the torque converter of this embodiment. The control system includes a speed regulation module (not shown) and a torque regulation module (not shown).

[0089] Among them, the speed regulation module is essentially used to implement the speed regulation stage in the control method of the torque converter of this embodiment, that is, it is used to determine the target impeller speed and adjust the output torque of the engine until the impeller speed reaches or exceeds the target impeller speed. The target impeller speed is the current turbine speed or the superposition value of the current turbine speed and the pre-calibrated speed parameter.

[0090] The torque regulation module is essentially used to implement the torque regulation stage in the control method of the torque converter of this embodiment, that is, it is triggered after the impeller speed reaches or exceeds the target impeller speed, and adjusts the output torque of the engine with a preset torque gradient until the output torque of the engine reaches the required target torque.

[0091] Optionally, in an accelerator pedal-operated condition, before the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed, and the speed regulation module is further configured to:

[0092] First, the current turbine speed is used as the target pump speed, and the engine output torque is adjusted until the pump speed reaches or exceeds the current turbine speed;

[0093] After the impeller speed reaches or exceeds the current turbine speed, the sum of the current turbine speed and the pre-calibrated speed parameter is used as the target impeller speed, and the output torque of the engine is continuously adjusted until the impeller speed reaches or exceeds the sum.

[0094] Optionally, under the accelerator pedal working condition, the speed regulating module adjusts the engine output torque T des =MN(T drv ,T dessyn ), and / or, the output torque T of the engine regulated by the torque regulation module des =MN(T drv ,T desold +T grad ), where MN() is the minimum function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the second speed regulation stage, T grad is the engine torque gradient value.

[0095] Optionally, under the throttle release condition, before the impeller speed crosses the turbine speed, the impeller speed is higher than the current turbine speed; the speed regulation module is used to use the difference between the current turbine speed and a pre-calibrated speed parameter as the target impeller speed, and adjust the output torque of the engine until the impeller speed reaches or is lower than the difference.

[0096] Optionally, under the throttle release condition, the output torque of the engine adjusted by the speed adjustment module is T des =MX(T drv ,T dessyn ), and / or, the output torque of the engine adjusted by the torque adjustment module is T des =MX(T drv ,T desold -T grad );

[0097] Among them, MX() is the maximum value function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

[0098] Optionally, the torque adjustment module is also used to adjust the gas path torque T required by the engine. lead Adjust the engine's gas path torque T lead =T des +T(N pump ,mifa), where T lead Indicates the gas circuit torque required by the engine clutch end, N pump represents the actual pump wheel speed, mifa represents the driver's required torque, T(N pump ,mifa) is obtained by pre-calibration.

[0099] In addition, please refer to Figure 7, combined with the two examples in the above-mentioned control method, it can be seen that the control method of the torque converter of this embodiment can divide the control process of the torque converter coupling point into seven states: initialization, standby, throttle speed adjustment I, throttle speed adjustment II, throttle torque adjustment, throttle speed adjustment, and throttle torque adjustment. Therefore, optionally, the control system of this embodiment also includes a state machine, which has seven states: initialization, standby, throttle speed adjustment I, throttle speed adjustment II, throttle torque adjustment, throttle speed adjustment, and throttle torque adjustment, and the state machine jumps to another state according to the throttle opening, impeller speed, engine required torque, and whether the lockup clutch of the torque converter is in the open state.

[0100] Among them, please refer to Figures 5 to 7 The functions and main implementation contents of these seven states are as follows:

[0101] ① Initialization: Set the state machine to the initialization state, set the speed control and torque control to the invalid state, and set the engine output torque T under the accelerator pedal condition. des And the gas circuit required torque T lead =1000, and the engine output torque T is set under the throttle release condition. des And the gas circuit required torque T lead is 0.

[0102] ② Standby: Set the state machine to standby state, set the speed adjustment and torque adjustment to invalid state, and set the target pump speed to 0.

[0103] ③Accelerator speed adjustment I: Set the state machine to accelerator speed adjustment I, activate the speed adjustment stage flag, and set the target pump speed to N turb , and calculate the engine output torque T at this stage according to formulas (1)-(4) and (6) in Example 1 des And the gas circuit required torque T lead .

[0104] ④Accelerator speed adjustment II: Set the state machine to accelerator speed adjustment II, activate the speed adjustment stage flag, and set the target pump speed to N turb +ofsa, and calculate the engine output torque T at this stage according to formulas (1)-(4) and (6) in Example 1 des And the gas circuit required torque T lead .

[0105] ⑤ Accelerator torque adjustment: Set the state machine to accelerator torque adjustment, turn off the speed adjustment stage flag, activate the torque adjustment stage flag, and calculate the engine output torque T in this stage according to formulas (5) and (6) in Example 1 des And the gas circuit required torque Tlead .

[0106] ⑥ Release throttle speed adjustment: Set the state machine to release throttle speed adjustment, activate the speed adjustment stage flag, and set the target pump speed to N turb -ofsb, calculate the engine output torque T at this stage according to formulas (2)-(4), (6) in Example 1 and formula (7) in Example 2 des And the gas circuit required torque T lead .

[0107] ⑦ Release throttle torque adjustment: Set the state machine to release throttle torque adjustment, turn off the speed adjustment stage flag, activate the torque adjustment stage flag, and calculate the output torque T of this stage according to formula (6) in example 1 and formula (8) in example 2 des And the gas circuit required torque T lead .

[0108] The state machine in this embodiment can jump to another state according to the throttle opening, pump wheel speed, engine torque requirement and whether the lockup clutch of the torque converter is in the open state. Figure 7 , the detailed conversion process is as follows:

[0109] (1) The system will enter the initialization state when the following conditions are met.

[0110] ① When the system is in the accelerator torque adjustment state, if the throttle opening wped_w>0 and the engine demand torque T des ≥T drv , and the lock-up clutch of the torque converter is in the open state (i.e. Figure 7 When convergests=open in , the state machine will jump from the throttle torque adjustment state to the initialization state.

[0111] ② When the system is in the throttle release torque adjustment state, if the throttle opening wped_w=0 and the engine demand torque T des ≤T drv , and when the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle release torque adjustment state to the initialization state.

[0112] ③ When the system is in the throttle release speed adjustment state, if the throttle opening wped_w>0, the pump wheel speed N pump ≥N turb +ofsa and the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle release torque adjustment state to the initialization state.

[0113] (2) The system will enter standby mode when the following conditions are met.

[0114] ① When the system is in the initialization state, if the throttle opening wped_w = 0 and the torque converter clutch is in the open state, the state machine will jump from the initialization state to the standby state.

[0115] ② When the system is in the accelerator speed adjustment state I, if the throttle opening wped_w=0 and the pump speed N pump ≤N turb When the lockup clutch of the torque converter is in the open state, the state machine will jump from the accelerator speed adjustment I state to the initialization state.

[0116] (3) When the following conditions are met, the system will enter the accelerator speed adjustment state I.

[0117] ① When the system is in standby mode, if the throttle opening wped_w>0, the pump speed N pump <N turb When the lockup clutch of the torque converter is in the open state, the state machine will jump from the standby state to the accelerator speed adjustment I state.

[0118] ② When the system is in the throttle release speed adjustment state, if the throttle opening wped_w>0, the pump wheel speed N pump ≤N turb When the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle-release speed adjustment state to the throttle-pressed speed adjustment I state.

[0119] (IV) When the following conditions are met, the system will enter the accelerator speed adjustment II state.

[0120] ① When the system is in the accelerator speed adjustment state I, if the throttle opening wped_w>0, the pump speed N pump ≥Nt urb And when the lock-up clutch of the torque converter is in the open state, the state machine will jump from the throttle speed adjustment I state to the throttle speed adjustment II state.

[0121] ② When the system is in the throttle release speed adjustment state, if the throttle opening wped_w>0, the pump wheel speed N pump <N turb +ofsa and the lock-up clutch of the torque converter is in the open state, the state machine will jump from the throttle-off speed adjustment state to the throttle-on speed adjustment II state.

[0122] (5) When the following conditions are met, the system will enter the throttle torque adjustment state.

[0123] When the system is in the accelerator speed regulation II state, if the throttle opening wped_w>0, the pump wheel speed N pump >N turb+ofsa and the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle speed regulation II state to the throttle torque regulation state.

[0124] (6) When the following conditions are met, the system will enter the throttle release speed adjustment state.

[0125] ① When the system is in standby mode, if the throttle opening wped_w=0 and the pump speed N pump ≥N turb And when the lockup clutch of the torque converter is in the open state, the state machine will jump from the standby state to the throttle release speed adjustment state.

[0126] ② When the system is in the accelerator speed regulation II state, if the throttle opening wped_w=0 and the pump speed N pump ≥N turb When the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle-on speed adjustment II state to the throttle-off speed adjustment state.

[0127] (7) When the following conditions are met, the system will enter the throttle release torque adjustment state.

[0128] When the system is in the throttle release speed regulation state, if the throttle opening wped_w=0 and the pump wheel speed N pump <N turb -ofsb and the lockup clutch of the torque converter is in the open state, the state machine will jump from the throttle-off speed adjustment state to the throttle-off torque adjustment state.

[0129] It should be understood that the control method and control system of the torque converter of this embodiment are mainly implemented near the coupling point of the torque converter, so it needs to be triggered. Please refer to Figure 8 The triggering steps that can be implemented by the control method or control system of this embodiment are specifically as follows:

[0130] 1) Determine whether the engine speed is greater than 0. If so, proceed to step 2); otherwise, jump to step 6);

[0131] 2) Determine whether the lockup clutch of the torque converter is open. If so, proceed to step 3); otherwise, jump to step 6);

[0132] 3) Determine whether the transmission is in a non-P gear. If so, proceed to step 4); otherwise, jump to step 6);

[0133] 4) Determine whether the transmission is in a non-N gear. If so, proceed to step 5); otherwise, jump to step 6);

[0134] 5) Activate the control function of the torque converter coupling point of this embodiment, implement the above-mentioned control method of the torque converter of this embodiment, or use the state machine control logic in the control system of the torque converter of this embodiment to control the pump wheel speed to pass through the torque converter coupling point.

[0135] 6) End.

[0136] In addition, it should be noted that the control method, control system or readable computer storage medium of the torque converter of the present invention can be integrated into the engine management system (EMS) of an automobile for implementation, or can be integrated into other systems that can control the engine torque, such as a hybrid vehicle controller (Hybrid Control Unit, HCU), an automatic transmission controller (Transmission Control Unit, TCU), etc.

[0137] To sum up, the technical solution of the present invention implements a segmented control strategy that combines the speed regulation stage with the torque regulation stage when the impeller speed passes through the torque converter coupling point. This can effectively improve the turbine speed oscillation and impact problems at the torque converter coupling point, enhance the driver's driving experience, and has significantly outstanding effects compared with existing technical solutions. It can be applied to automotive transmissions such as continuously variable transmissions (CVT) and automatic transmissions (AT) with torque converters.

[0138] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of the technical solution of the present invention.

Claims

1. A method for controlling a torque converter having a pump connected to an engine and a turbine connected to a transmission, the method being configured to achieve a process in which the pump speed crosses the turbine speed, and comprising: In the speed regulation stage, a target impeller speed is determined and the engine output torque is adjusted until the impeller speed reaches or exceeds the target impeller speed, which is the sum of the current turbine speed and a pre-calibrated speed parameter. The torque adjustment phase is triggered after the impeller speed reaches or exceeds the target impeller speed, and the engine output torque is adjusted with a preset torque gradient until the engine output torque reaches the required target torque; Wherein, under the accelerator pedal working condition, before the pump impeller speed crosses the turbine speed, the pump impeller speed is lower than the current turbine speed, and after the pump impeller speed crosses the turbine speed, the pump impeller speed is higher than the current turbine speed, and the superposition value is the sum of the current turbine speed and the pre-calibrated speed parameter; Under the throttle release condition, before the pump speed crosses the turbine speed, the pump speed is higher than the current turbine speed. After the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed, and the superimposed value is the difference between the current turbine speed and the pre-calibrated speed parameter.

2. The control method according to claim 1, wherein: Under the accelerator pedal working condition, before the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed; The speed regulation stage also includes: In the first speed adjustment stage, the engine output torque is adjusted with the current turbine speed as the target pump speed until the pump speed reaches or exceeds the current turbine speed. The second speed regulation stage is triggered after the impeller speed reaches or exceeds the current turbine speed, and the target impeller speed is the sum of the current turbine speed and the pre-calibrated speed parameter, and the output torque of the engine is continued to be adjusted until the impeller speed reaches or exceeds the sum.

3. The control method according to claim 1, wherein: Under the accelerator pedal working condition, the output torque T of the engine in the speed regulation stage is des =MN(T drv ,T dessyn ), and / or, the output torque T of the engine during the torque adjustment phase des =MN(T drv ,T desold + T grad ); Among them, MN() is the minimum function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

4. The control method according to claim 1, wherein: Under the throttle release condition, before the impeller speed crosses the turbine speed, the impeller speed is higher than the current turbine speed; in the speed adjustment stage, the difference between the current turbine speed and the pre-calibrated speed parameter is used as the target impeller speed, and the output torque of the engine is adjusted until the impeller speed reaches or is lower than the difference.

5. The control method according to claim 1, wherein: Under the throttle release condition, the engine output torque T des =MX(T drv ,T dessyn ), and / or, the output torque T of the engine during the torque adjustment phase des =MX(T drv ,T desold -T grad ); Among them, MX() is the maximum value function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

6. The control method according to any one of claims 1 to 4, characterized in that: The torque adjustment stage also requires the engine's gas circuit torque T lead Adjust the engine's gas path torque T lead =T des +T(N pump ,mifa), where T lead Indicates the gas circuit torque required by the engine clutch end, N pump represents the actual pump wheel speed, mifa represents the driver's required torque, T(N pump ,mifa) is obtained by pre-calibration.

7. A control system for a torque converter having a pump connected to an engine and a turbine connected to a transmission, the control system being configured to achieve a process in which the pump speed crosses the turbine speed, and comprising: a speed regulation module, configured to determine a target impeller speed during a speed regulation phase and regulate the engine output torque until the impeller speed reaches or exceeds the target impeller speed, the target impeller speed being a sum of the current turbine speed and a pre-calibrated speed parameter; a torque adjustment module, configured to be triggered after the impeller speed reaches or exceeds the target impeller speed, and adjust the output torque of the engine with a preset torque gradient until the output torque of the engine reaches the required target torque; Wherein, under the accelerator pedal working condition, before the pump impeller speed crosses the turbine speed, the pump impeller speed is lower than the current turbine speed, and after the pump impeller speed crosses the turbine speed, the pump impeller speed is higher than the current turbine speed, and the superposition value is the sum of the current turbine speed and the pre-calibrated speed parameter; Under the throttle release condition, before the pump speed crosses the turbine speed, the pump speed is higher than the current turbine speed. After the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed, and the superimposed value is the difference between the current turbine speed and the pre-calibrated speed parameter.

8. The control method according to claim 7, characterized in that Under the accelerator pedal operation condition, before the pump speed crosses the turbine speed, the pump speed is lower than the current turbine speed; the speed regulation module is further configured to: First, the current turbine speed is used as the target pump speed, and the engine output torque is adjusted until the pump speed reaches or exceeds the current turbine speed; After the impeller speed reaches or exceeds the current turbine speed, the sum of the current turbine speed and the pre-calibrated speed parameter is used as the target impeller speed, and the output torque of the engine is continuously adjusted until the impeller speed reaches or exceeds the sum.

9. The control system according to claim 7, wherein: Under the accelerator pedal working condition, the speed regulating module regulates the output torque T of the engine. des =MN(T drv , T dessyn ), and / or, the output torque T of the engine adjusted by the torque adjustment module des =MN(T drv ,T desold + T grad ); Among them, MN() is the minimum function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

10. The control system according to claim 7, wherein: Under the throttle release condition, before the impeller speed crosses the turbine speed, the impeller speed is higher than the current turbine speed; the speed regulation module is used to use the difference between the current turbine speed and the pre-calibrated speed parameter as the target impeller speed, and adjust the output torque of the engine until the impeller speed reaches or is lower than the difference.

11. The control system according to claim 10, wherein: Under the throttle release condition, the speed regulation module regulates the engine output torque T des =MX(T drv ,T dessyn ), and / or, the output torque of the engine adjusted by the torque adjustment module is T des =MX(T drv ,T desold -T grad ); Among them, MX() is the maximum value function, T drv is the driver's required torque, T dessyn is the target torque value related to the pump speed regulation, T desold is the required torque value of the engine at the previous moment, T desold The initial value of is the engine required torque value at the end of the speed regulation phase, T grad is the engine torque gradient value.

12. The control system according to any one of claims 7 to 11, characterized in that: The torque adjustment module is also used to adjust the engine's gas circuit torque T lead Adjust the engine's gas path torque T lead =T des +T(N pump ,mifa), where T lead Indicates the gas circuit torque required by the engine clutch end, N pump represents the actual pump wheel speed, mifa represents the driver's required torque, T(N pump ,mifa) is obtained by pre-calibration.

13. The control system according to any one of claims 7 to 11, characterized in that: It also includes a state machine, which has seven states: initialization, standby, throttle speed adjustment I, throttle speed adjustment II, throttle torque adjustment, throttle release speed adjustment, and throttle release torque adjustment. The state machine jumps to another state according to the throttle opening, pump wheel speed, engine required torque, and whether the lockup clutch of the torque converter is in the open state.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method of the torque converter according to any one of claims 1 to 6 is implemented.

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