CN111779773A

CN111779773A - Clutch control method and device of double-motor hybrid system

Info

Publication number: CN111779773A
Application number: CN202010107783.9A
Authority: CN
Inventors: 刘义强; 黄亮; 王运凯
Original assignee: Zhejiang Geely Holding Group Co Ltd; Yiwu Geely Powertrain Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Yiwu Geely Powertrain Co Ltd
Priority date: 2020-02-21
Filing date: 2020-02-21
Publication date: 2020-10-16
Anticipated expiration: 2040-02-21
Also published as: CN111779773B

Abstract

The invention relates to a clutch control method and a device of a double-motor hybrid system, wherein the method comprises the following steps: judging whether the current accelerator working state is in a quick unlocking state or a quick closing state; when the accelerator working state is in a quick unlocking state or a quick closing state, the clutch is driven to enter a sliding friction working state, and the clutch is partially unlocked; then driving the clutch to exit the sliding friction working state; then partially locking the clutch and acquiring the rotation speed difference at two ends of the clutch; controlling the rotation speed difference to continuously meet a preset rotation speed difference value until a part of the locking clutches are locked to be completely locked; the invention can improve the change of the contact surface of the input gear and the output gear, avoid the impact and the noise generated by the inter-tooth clearance, optimize the driving performance and simultaneously maintain the quick response of the engine torque.

Description

Clutch control method and device of double-motor hybrid system

Technical Field

The invention relates to the technical field of hybrid power, in particular to a clutch control method and device of a dual-motor hybrid system.

Background

Along with the development of economy and the reduction of traditional energy, more and more automobile manufacturers research and develop hybrid electric vehicles to replace traditional energy vehicles, can solve the reduction of traditional energy, and also meet the travel demands of daily people.

When an engine directly drives a vehicle, the accelerator (TipIn) is suddenly and quickly stepped on under the condition of small accelerator or accelerator release, the engine is required to quickly output large positive torque when the engine is suddenly stepped on because the actual output is small torque under the condition of small accelerator/zero accelerator of the engine or negative torque when the resistance, loss and the like of the engine are overcome, for a power system, the whole transmission torque undergoes a process from negative to positive, sudden impact torque is generated on the transmission system, and noise and impact are easily generated.

On the contrary, when the engine directly drives the vehicle, the accelerator is suddenly released (Tip Out) under the condition of a large accelerator, the accelerator is suddenly released and the engine is cut off due to the fact that the engine actually outputs large positive torque, the accelerator is suddenly released, the engine is cut off, negative torque is actually output due to the fact that self resistance, loss and the like are overcome, for a power system, the whole transmission torque goes through a positive-to-negative process, sudden impact torque is generated on the transmission system, and noise and impact are easily generated.

At present, in order to reduce the space in the prior art, a transmission mechanism generally adopts a multi-shaft linkage mechanism, a shaft is connected with a shaft through a gear train, and gear connection is realized by mutual meshing of two gear teeth, wherein, a) under the condition of negative torque, an output gear drags an input gear to transmit power, and at the moment, the tooth surface of the output gear pushes the tooth surface of the input gear; b) under the condition of positive torque, the input gear drags the output gear to transmit power, the tooth surface of the input gear pushes the tooth surface of the output gear, and due to the existence of the gap between the gear teeth, when the input torque is changed from negative to positive or from positive to negative, the contact surface of the input gear and the output gear is changed, so that impact and noise are easily generated, and particularly, the backlash impact and noise are more obvious in a main speed reducer and a differential mechanism part after the torque is amplified by a speed ratio of a gearbox.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a method and an apparatus for controlling a clutch of a dual motor hybrid system, which can improve the change of the contact surface between an input gear and an output gear, avoid the generation of impact and noise due to the backlash, optimize drivability, and maintain the quick response of the engine torque.

In order to solve the above problems, the present invention provides a clutch control method for a dual-motor hybrid system, comprising the steps of:

judging whether the current accelerator working state is in a quick unlocking state or a quick closing state;

when the accelerator working state is in a quick opening state or a quick closing state, acquiring the current rotating speed of the engine and the corresponding crankshaft end torque;

determining the time when the clutch enters a sliding friction working state and the time when the clutch exits the sliding friction working state according to the current rotating speed and the corresponding crankshaft end torque;

partially unlocking the clutch when the clutch enters the slip friction operating state;

when the clutch is out of the sliding friction working state, partially locking the clutch and acquiring a rotation speed difference between two ends of the clutch;

and controlling the rotation speed difference to continuously meet a preset rotation speed difference value until the clutch is partially locked to be completely locked.

Further, the step of judging whether the accelerator working state is in a quick unlocking state or a quick closing state comprises the steps of:

obtaining crankshaft end torque without filtering processing and crankshaft end torque after filtering processing;

calculating a torque difference value through the crankshaft end torque which is not subjected to filtering processing and the crankshaft end torque which is subjected to filtering processing;

judging whether the torque difference value is larger than a preset torque difference value or not;

when the torque difference value is larger than the preset torque difference value, the current accelerator working state is in the quick opening state;

and when the torque difference value is not greater than the preset torque difference value, the current accelerator working state is in the quick closing state.

Further, the crankshaft end torque after the filtering processing is the engine crankshaft end torque after the filtering processing is performed according to a preset filter coefficient.

Further, determining the timing of whether the clutch enters the slip friction operating state and the timing of exiting the slip friction operating state according to the current rotation speed and the corresponding crankshaft end torque further includes:

judging whether the current rotating speed and the crankshaft end torque simultaneously meet preset conditions;

and if the current rotating speed and the crankshaft end torque simultaneously meet the preset condition, driving the clutch to enter the sliding friction working state.

And if the current rotating speed and the crankshaft end torque do not meet the preset condition at the same time, driving the clutch to exit the sliding friction working state.

Further, judging whether the current rotating speed and the crankshaft end torque simultaneously meet preset conditions is to judge whether the current rotating speed meets a preset rotating speed value, and simultaneously judging whether the crankshaft end torque meets a preset crankshaft end torque value.

Further, the degree of partial unlocking of the clutch depends on the degree of opening and closing of the throttle.

Further, the extent of the partial lock-up clutch depends on the difference in rotational speed across the clutch.

Further, controlling the rotational speed difference to continuously satisfy a preset rotational speed difference until partially locking the clutch to the full lock-up clutch further includes:

controlling the rotation speed difference to gradually decrease according to a preset rotation speed difference value;

when the rotating speed difference reaches a preset rotating speed difference threshold value, reducing the current torque of the clutch to a preset torque value according to a preset speed;

and when the current torque reaches a preset target torque value, partially locking the clutch to completely locking the clutch.

The invention also protects a clutch control device of the double-motor hybrid system, which comprises the following components:

the state judgment module is used for judging whether the current accelerator working state is in a quick unlocking state or a quick closing state;

the acquisition module is used for acquiring the current rotating speed of the engine and the corresponding crankshaft end torque when the accelerator working state is in a quick opening state or a quick closing state;

a determination module to determine whether the clutch enters or exits the slip friction operating state based on the current rotational speed and the corresponding crankshaft end torque

The first execution module is used for partially unlocking the clutch when the clutch enters the sliding friction working state;

the second execution module is used for partially locking the clutch when the clutch is out of the sliding friction working state, and acquiring a rotation speed difference between two ends of the clutch;

and the rotating speed difference control module is used for controlling the rotating speed difference to continuously meet a preset rotating speed difference value until the clutch is partially locked to be completely locked.

Further, the state judgment module comprises:

the crankshaft end torque acquisition unit is used for acquiring crankshaft end torque which is not subjected to filtering processing and crankshaft end torque which is subjected to filtering processing;

the torque difference calculation unit is used for calculating a torque difference value through the crankshaft end torque which is not subjected to filtering processing and the crankshaft end torque which is subjected to filtering processing;

the second judgment unit is used for judging whether the torque difference value is larger than a preset torque difference value or not;

the first working state determining unit is used for determining that the current accelerator working state is in a quick opening state when the torque difference value is larger than the preset torque difference value;

and the second working state determining unit is used for determining that the current accelerator working state is in a quick closing state when the torque difference value is not greater than the preset torque difference value.

Due to the technical scheme, the invention has the following beneficial effects:

the clutch control method and device of the double-motor hybrid system are applied to the situation that double motors in the double-motor hybrid system are in a parallel mode, when an accelerator is quickly pressed down or quickly released to generate input torque from negative to positive or from positive to negative, the change of the contact surface of an input gear and an output gear can be improved, impact and noise generated by gaps between teeth can be avoided, the driving performance can be optimized, and meanwhile, the quick response of the torque of an engine can be maintained.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiment or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a flowchart of a clutch control method of a dual-motor hybrid system according to an embodiment of the present invention;

FIG. 2 is a flowchart of step S102 provided by an embodiment of the present invention;

fig. 3 is a flowchart of step S103 provided by the embodiment of the present invention;

FIG. 4 is a flowchart of step S106 provided by an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a clutch control device of a two-motor hybrid system according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a state determination module according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a determining module according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a differential rotational speed control module according to an embodiment of the present invention;

fig. 9 is a schematic partial structural diagram of a clutch control device of a dual-motor hybrid system according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "top", "bottom", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms first, second, and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein.

Example one

The embodiment provides a clutch control method of a dual-motor hybrid system, as shown in fig. 1, including the following steps:

s101, judging whether the current accelerator working state is in a quick unlocking state or a quick closing state;

s102, when the accelerator working state is in a quick opening state or a quick closing state, acquiring the current rotating speed of the engine and the corresponding crankshaft end torque;

s103, determining the time when the clutch enters the sliding friction working state and the time when the clutch exits the sliding friction working state according to the current rotating speed and the corresponding crankshaft end torque;

s104, partially unlocking the clutch when the clutch enters the sliding friction working state;

s105, when the clutch is out of the sliding friction working state, partially locking the clutch, and acquiring a rotation speed difference between two ends of the clutch;

and S106, controlling the rotation speed difference to continuously meet a preset rotation speed difference value until the clutch is partially locked to be completely locked.

As shown in fig. 2, the determining that the current accelerator operating state is in the fast-open state or the fast-close state includes:

s201, obtaining crankshaft end torque which is not subjected to filtering processing and crankshaft end torque which is subjected to filtering processing;

s202, calculating a torque difference value through the crankshaft end torque which is not subjected to filtering processing and the crankshaft end torque which is subjected to filtering processing;

s203, judging whether the torque difference value is larger than a preset torque difference value;

s204, when the torque difference value is larger than the preset torque difference value, the current accelerator working state is in the quick opening state;

s205, when the torque difference value is not larger than the preset torque difference value, the current accelerator working state is in the quick closing state.

As shown in fig. 3, the timing of determining whether the clutch enters the slip friction operating state and the timing of exiting the slip friction operating state according to the current rotation speed and the corresponding crankshaft end torque further include

S301, judging whether the current rotating speed and the crankshaft end torque simultaneously meet preset conditions;

s302, if the current rotating speed and the crankshaft end torque simultaneously meet the preset condition, the clutch is driven to enter the sliding friction working state.

And S303, if the current rotating speed and the crankshaft end torque do not meet the preset condition at the same time, driving the clutch to exit the sliding friction working state.

As shown in fig. 4, controlling the rotational speed difference to continuously satisfy the preset rotational speed difference until the clutch is partially locked to the full lock-up clutch further includes:

s401, controlling the rotation speed difference to gradually decrease according to a preset rotation speed difference value;

s402, when the rotating speed difference reaches a preset rotating speed difference threshold value, reducing the current torque of the clutch to a preset torque value according to a preset speed;

and S403, when the current torque reaches a preset target torque value, partially locking the clutch until the clutch is completely locked.

Further, the clutch is locked according to a preset locking rate from partial locking to complete locking of the clutch.

The present embodiment further provides a clutch control device of a dual-motor hybrid system, as shown in fig. 5, including:

the state judgment module 10 is used for judging whether the current accelerator working state is in a quick unlocking state or a quick closing state;

the acquiring module 20 is configured to acquire a current rotation speed of the engine and a corresponding crankshaft end torque when the accelerator working state is in a fast opening state or a fast closing state;

the determining module 30 is configured to determine, according to the current rotation speed and the corresponding crankshaft end torque, whether the clutch enters a sliding friction operating state or not and whether the clutch exits the sliding friction operating state;

a first executing module 40 for partially unlocking the clutch when the clutch enters the sliding friction operating state;

a second executing module 50, configured to partially lock the clutch and obtain a difference in rotation speed between two ends of the clutch when the clutch exits the slip friction operating state;

and a differential rotation speed control module 60 configured to control the differential rotation speed to continuously satisfy a preset differential rotation speed until the clutch is partially locked to the fully locked clutch.

As shown in fig. 6, the state determining module 10 further includes:

a crankshaft end torque obtaining unit 101, configured to obtain a crankshaft end torque without filter processing and a crankshaft end torque after filter processing;

a torque difference calculation unit 102, configured to calculate a torque difference value according to the unfiltered crankshaft end torque and the filtered crankshaft end torque;

a first judging unit 103, configured to judge whether the torque difference is greater than a preset torque difference;

a first working state determining unit 104, configured to, when the torque difference is greater than the preset torque difference, set the current accelerator working state to be in a fast-open state;

and a second working state determining unit 105, wherein when the torque difference is not greater than the preset torque difference, the current accelerator working state is in a quick closing state.

As shown in fig. 7, the determining module 30 includes:

a second judging unit 301, configured to judge whether the current rotation speed and the crankshaft end torque simultaneously satisfy a preset condition;

and the first clutch execution unit 302 is used for driving the clutch to enter a sliding friction working state if the current rotating speed and the crankshaft end torque simultaneously meet preset conditions.

And the second clutch executing unit 303 is configured to drive the clutch to exit the sliding friction operating state if the current rotation speed and the crankshaft end torque do not simultaneously satisfy the preset condition.

As shown in fig. 8, the differential rotational speed control module 60 further includes:

the third executing unit 601 is configured to control the rotation speed difference to gradually decrease according to a preset rotation speed difference value;

a fourth executing unit 602, configured to reduce, when the rotational speed difference reaches a preset rotational speed difference threshold, a current torque of the clutch to a preset torque value according to a preset rate;

a second non-execution unit 603, configured to partially lock the clutch to completely lock the clutch when the current torque reaches a preset target torque value.

The embodiment provides a clutch control method and device for a dual-motor hybrid system, which can improve the change of contact surfaces of an input gear and an output gear, avoid impact and noise generated by a gap between teeth, optimize drivability, and maintain quick response of engine torque.

It is noted that while for simplicity of explanation, the foregoing method embodiments have been presented as a series of interrelated states or acts, it should be appreciated by those skilled in the art that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Similarly, the modules of the clutch control device of the two-motor hybrid system are referred to as a computer program or a program segment for executing one or more specific functions, and the division of the modules does not represent actual program codes and must be separated. Further, the above embodiments may be arbitrarily combined to obtain other embodiments.

In the foregoing embodiments, the descriptions of the embodiments have respective emphasis, and reference may be made to related descriptions of other embodiments for parts that are not described in detail in a certain embodiment. Those of skill in the art will further appreciate that the various illustrative logical blocks, elements, and steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate the interchangeability of hardware and software, various illustrative components, elements, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design requirements of the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present embodiments.

The foregoing description has disclosed fully preferred embodiments of the present invention. It should be noted that those skilled in the art can make modifications to the embodiments of the present invention without departing from the scope of the claims. Accordingly, the scope of the claims of the present invention is not to be limited to the specific embodiments described above.

Claims

1. A clutch control method of a dual-motor hybrid system is characterized by comprising the following steps:

when the clutch is withdrawn from the sliding friction working state, partially locking the clutch and acquiring a rotation speed difference between two ends of the clutch;

2. The clutch control method of the dual-motor hybrid electric system according to claim 1, wherein the judging whether the accelerator operating state is in a fast-open state or a fast-close state comprises:

3. The clutch control method of the two-motor hybrid electric system according to claim 2, wherein the filtered crankshaft end torque is an engine crankshaft end torque after filtering according to a preset filter coefficient.

4. The method as claimed in claim 1, wherein the determining the timing of whether the clutch enters the slip friction operating state and the timing of exiting the slip friction operating state according to the current rotation speed and the corresponding crankshaft end torque further comprises

5. The clutch control method of a dual-motor hybrid electric system according to claim 4, wherein the determining whether the current rotation speed and the crankshaft end torque satisfy the predetermined condition at the same time is determining whether the current rotation speed satisfies a predetermined rotation speed value and determining whether the crankshaft end torque satisfies a predetermined crankshaft end torque value at the same time.

6. The clutch control method of a two-motor hybrid system according to claim 1, wherein the degree of partial unlocking of the clutch depends on the degree of opening and closing of the throttle.

7. The clutch control method of a two-motor hybrid system according to claim 1, wherein the degree of the partial lock-up clutch depends on the difference in the rotational speed across the clutch.

8. The clutch control method of a two-motor hybrid electric system according to claim 1, wherein controlling the rotational speed difference to continuously satisfy a preset rotational speed difference until partially locking the clutch to fully locking the clutch further comprises:

9. A clutch control device of a dual-motor hybrid system, characterized by comprising:

the determining module is used for determining the time when the clutch enters the sliding friction working state and the time when the clutch exits the sliding friction working state according to the current rotating speed and the corresponding crankshaft end torque;

10. The clutch control device of a two-motor hybrid electric system according to claim 9, wherein the state determination module includes: