WO2023279634A1

WO2023279634A1 - Upshift control method

Info

Publication number: WO2023279634A1
Application number: PCT/CN2021/134187
Authority: WO
Inventors: 苏宇; 林霄喆; 孙艳; 谭艳军; 付军; 张旭; 王二朋; 王开文; 张恒; 孙剑斌; 李江; 赵欣; 王瑞平
Original assignee: 义乌吉利自动变速器有限公司; 宁波吉利罗佑发动机零部件有限公司; 极光湾科技有限公司; 浙江吉利控股集团有限公司
Priority date: 2021-07-08
Filing date: 2021-11-29
Publication date: 2023-01-12
Also published as: CN113653797B; CN113653797A

Abstract

An upshift control method, comprising the following steps: in a pre-charging phase, when a first brake and a second brake meet a preset condition, the torque of an engine is reduced to a preset torque and a clutch C0 adjusts a pressure according to the torque demand of the engine; in a torque phase, the torque of the first brake is adjusted to a first torque, the torque of the second brake is adjusted to a second torque, and the torque of a drive motor works along an external characteristic curve; in a rotating speed phase, an input shaft rotating speed is adjusted to a target shift rotating speed, the torque of the second brake is increased, the torque of the drive motor is increased, and a generator outputs a reverse torque; and in a closing phase, the rotating speeds of the engine and the drive motor are synchronized, the torque of the first brake is reduced to zero, the torque of the second brake is provided with an additional safe torque, the torque of the generator is zero, external characteristic torque control is applied to the engine torque according to the current rotating speed, and the clutch C0 is locked according to the engine torque.

Description

Upshift control method

technical field

The invention relates to the technical field of hybrid power, in particular to an upshift control method.

Background technique

The development of transmission has gone through manual transmission, automatic transmission, automatic manual transmission, dual-clutch transmission, and current hybrid transmission. A key technology in the transmission is shift control. With the development of the transmission, the shifting method of the transmission is also updated.

In the current market, there is a phenomenon of shaft cracking when the engine and the motor are rigidly connected or indirectly rigidly connected, and there are problems with double-mass flywheel engines. These phenomena are not easy to be detected at the beginning of the design and are easy to occur. Most of the automatic transmissions and hybrid transmissions on the market use AT shift control strategies and DCT shift strategies, but these two methods do not take into account the physical hardware structural characteristics of hybrid transmissions.

For example, when a high-torque power upshift shifts, the engine produces a large torque, and the P3 motor produces a large negative torque in the reverse direction. In the speed stage of the gear shift, the P1 spline shaft is subjected to a huge reverse torque impact. At this time, the dual If the mass flywheel is designed according to the traditional method or the design is too small, there will be a great risk of laps. It is feasible to use the method of reducing the engine torque to 0 to shift gears, but it is not conducive to engine combustion, that is, it is not conducive to economy, and it is easy to cause premature combustion.

Therefore, there is an urgent need for a flexible upshift control method to solve the above problems.

technical problem

The technical problem solved by the present invention is to provide an upshift control method, which can reduce the risk of dual-mass flywheel merging while ensuring smooth, smooth and dynamic shifting, and also reduce the reverse rotation of the P1 spline shaft. Bear torsion.

technical solution

The present invention solves its technical problem and adopts following technical scheme to realize:

An upshift control method, comprising the following steps: S1: pre-charging stage, when the first brake and the second brake meet the preset conditions, the engine torque is reduced to the preset torque, and the pressure of the clutch C0 is adjusted according to the engine torque demand ; S2: Torque stage, the first brake is reduced to the first torque, the second brake is increased to the second torque, and the driving motor torque works according to the preset strategy; S3: Speed stage, the input shaft speed is reduced to Target gear speed, the torque of the second brake increases, the torque of the driving motor increases, and the generator outputs reverse torque; S4: In the closing stage, the engine and the input shaft speed of the driving motor are synchronized, and the first The first brake torque is reduced to zero, the second brake torque is added with safety torque, the generator torque is adjusted to zero, the engine torque is controlled according to the current rotational speed, and the clutch C0 is locked according to the engine torque end.

In a preferred embodiment of the present invention, the above step S3 includes: when it is detected that the dual-mass flywheel is about to have an over-limit torque, triggering the slipping mechanism of the clutch C0, and through the clutch C0, within its energy capacity Within the acceptable range, carry out sliding friction control.

In a preferred embodiment of the present invention, the aforementioned preset conditions include: the first brake is adjusted to the second torque, and the second brake is precharged to the first torque.

In a preferred embodiment of the present invention, the aforementioned preset strategy is an external characteristic strategy.

In a preferred embodiment of the present invention, before the above step S1 includes: when the throttle opening is greater than a set throttle opening threshold and the power downshift will not be triggered in the current gear, it is determined to trigger the power upshift control, otherwise Continue to judge whether to trigger the power upshift control.

In a preferred embodiment of the present invention, the above step S2 includes: the torque of the generator is zero, and the engine maintains the preset torque.

In a preferred embodiment of the present invention, the above step S3 further includes: the second brake maintains the first torque, and the engine maintains the preset torque.

Beneficial effect

The technical effect achieved by adopting the above technical solution in the present invention is: for the rotational speed stage of the gear shifting process, the second brake can be used to adjust its torque to assist gear shifting under the condition of allowing the heat capacity and torque capacity to be used, and the load of the P1 spline shaft can be reduced . When the shift begins, reduce the engine to the proper torque. Use the slipping ability of the clutch C0 to protect the dual mass flywheel as well as the splined shaft of the P1 module. While ensuring smooth, smooth and dynamic gear shifting, it reduces the risk of dual mass flywheel (DMF) parallel laps, and also reduces the reverse bearing torque of the P1 spline shaft.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments will be described in detail in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a flow chart of an upshift control method shown in an embodiment of the present invention.

Fig. 2 is a schematic diagram of a 3DHT shown in an embodiment of the present invention.

Fig. 3 is a diagram showing the working principle of the embodiment of the present invention.

Fig. 4 is a schematic diagram of a step in the shift process shown in the embodiment of the present invention.

Embodiments of the present invention

In order to further set forth the technical means and effects that the present invention takes to achieve the intended purpose of the invention, the embodiments of the present invention are described in detail below, examples of the embodiments are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the embodiments of the present invention. Through the description of specific embodiments, the technical means and effects of the present invention to achieve the intended purpose can be understood more deeply and specifically, and the accompanying drawings are only for reference and description, and are not used to explain the present invention. limit.

Please refer to FIG. 1 to FIG. 4 . FIG. 1 is a flow chart showing an upshift control method according to an embodiment of the present invention.

As shown in Figure 1, the upshift control method of the present invention comprises the following steps:

S1: pre-charging stage, when the first brake and the second brake meet the preset conditions, the torque of the engine is reduced to the preset torque, and the pressure of the clutch C0 is adjusted according to the torque demand of the engine.

S2: Torque stage, the first brake is reduced to the first torque, the second brake is increased to the second torque, and the torque of the drive motor works according to a preset strategy.

S3: In the speed stage, the speed of the input shaft decreases to the speed of the target gear, the torque of the second brake increases, the torque of the driving motor increases, and the generator outputs reverse torque.

S4: In the closing stage, the engine is synchronized with the input shaft speed of the drive motor, the first brake torque is reduced to zero, the second brake torque is added with a safety torque, the generator torque is adjusted to zero, and the engine The torque is controlled according to the current rotational speed, and the clutch C0 is locked according to the engine torque.

Step S3 includes: triggering the slipping mechanism of the clutch C0 when it is detected that the dual-mass flywheel is about to have a super-current value torque, and performing slipping control through the clutch C0.

The preset conditions include: the second brake performs a pre-filling action to adjust the torque to the first torque, and the first brake reduces the torque to the second torque.

Specifically, the first torque is the clutch half-engagement point torque. The oil filling control takes the clutch pressure corresponding to the half-engagement point of the clutch as the oil filling target pressure, takes the current clutch pressure as the actual pressure, and performs calibration optimization according to the oil temperature of different gearboxes and the difference between the clutch oil filling target pressure and the actual pressure.

Wherein, the second torque is the slip torque, and the reduction of the first brake torque to the slip torque point can be understood as the torque at which the first brake and the system torque reach a balance.

The default strategy is the external characteristic strategy.

Among them, the external characteristics and partial characteristics of the engine are collectively referred to as the speed characteristics of the engine, and the external characteristic curve of the engine is the curve of the engine output power (torque) versus the rotational speed measured when the engine throttle opening is 100%.

Before step S1 includes: when the throttle opening is greater than a set throttle opening threshold and the power downshift will not be triggered in the current gear, determine to trigger the power upshift control, otherwise continue to determine whether to trigger the power upshift control.

Step S2 includes: the generator torque is zero, and the engine maintains the preset torque.

Step S3 further includes: the second brake maintains the first torque, and the engine maintains the preset torque.

The present invention is described in detail below in conjunction with Fig. 1 to Fig. 4:

Please refer to Fig. 2, Fig. 3 and Fig. 4, the power upshift of the hybrid transmission of the present invention is divided into four stages, which are pre-charging stage, torque stage, speed stage and closing stage.

In the pre-charging stage, the second brake (ongoing brake, Brake-2) performs a pre-charging action to make the clutch reach the half-engagement point (kiss point), and the first brake (offgoing brake, Brake-1) reduces torque to the slipping torque boundary. At this time, the engine starts to perform torque reduction control, and the clutch C0 (Clutch-0) will adjust the pressure according to the engine torque demand. Among them, the gear shift starts to reduce the engine to the appropriate torque, not zero torque. This torque can be considered from an economical point of view while reducing the torque while preventing the occurrence of pre-ignition.

In the torque phase, the input shaft remains unchanged, the offgoing brake starts to reduce torque to the slip torque point, and the second brake (ongoing brake, Brake-2) starts to increase torque to its half combined (kiss point) torque point. The torque of the drive motor works along the external characteristics, the generator maintains zero torque, the engine continues to maintain a low demand torque, and the clutch C0 adjusts the pressure according to the engine demand torque.

In the speed phase, the input shaft speed is reduced to the target gear speed, and the offgoing brake maintains a half-bonded point (kiss point), the second brake (ongoing brake, Brake-2) actively increases the torque under the condition that the thermal capacity of the brake and the torque allow, the auxiliary speed stage is completed, and the decrease in the input torque is alleviated. At this time, the drive motor starts to torque as the speed decreases. Increase, the generator reverses the torque, which is used for the reverse acceleration of the input shaft speed reduction, and the engine continues to maintain low torque output. In this process, if the system detects that the dual-mass flywheel is about to have a super-current value torque, it will trigger the clutch C0 to slip mechanism, prompting the drive motor and engine to produce a certain amount of friction, and at this time, rely on C0 to realize the friction control of the process. Among them, the engine, drive motor, and generator are coaxial in parallel mode, and this scheme describes gear shifting in parallel mode. Therefore, co-rotating. By using Brake2 to adjust its torque-assisted shifting under the condition of allowable capacity, it can not only ensure the smoothness of shifting, but also reduce the load on the P1 spline shaft. Then the dual mass flywheel and the spline shaft can be protected by using the slipping ability of the clutch C0 reasonably.

The clutch C0 adjusts the pressure for external output. When Tclu < TEng (clutch engagement torque is less than the engine torque, there will be slipping, this part of the closed-loop control C0 torque to control the corresponding speed difference, Tclu = TEng + Jα, where α accelerates in the opposite direction (-) when downshifting, so that the output torque is less than the engine torque when the clutch is slipping).

In the closing stage, the engine and the input shaft of the drive motor rotate at the same speed, the torque of the offgoing brake is reduced to 0, and the torque of the second brake (ongoing brake, Brake-2) is added with a safe torque. The motor maintains continuous output, the generator torque reaches 0, the engine torque outputs the characteristic torque according to the current speed, and the clutch C0 is locked according to the engine torque.

In the above embodiments, the second brake (ongoing brake, Brake-2) torque, driving motor torque, generator torque, engine torque, and clutch C0 torque can be appropriately changed according to actual conditions to combine optimal control. The execution sequence of the second brake (ongoing brake, Brake-2) torque, drive motor torque, generator torque, engine torque, and clutch C0 torque can be flexibly controlled to start and end. The torque control gradient can be optimized according to the actual situation.

Please refer to Figure 4, which shows a step in the shifting process and can be used as a reference. This figure is used to illustrate how to protect the coupling relationship of related hardware during the shift process; it can be used to analyze the torque relationship during the shift process. The formulas in the attached drawings can be used for the selection of hardware boundaries; they can also be used for the design and formulation of shift time and shift torque.

Optionally, the upshift control strategy described in the present invention can also be transformed into a control strategy for a power downshift shift process.

In the upshift control method provided by the present invention, the engine is reduced to an appropriate torque at the beginning of shifting, and the torque reduction is completed under the premise of preventing pre-ignition. For the speed phase of the shifting process, use Brake2 to adjust its torque-assisted shifting under the condition of allowable capacity, which can not only ensure the smoothness of shifting, but also reduce the load on the P1 spline shaft. By using the slipping ability of the clutch C0, the dual-mass flywheel and the spline shaft of the P1 module are effectively protected, preventing the dual-mass flywheel from lapping and the spline shaft from breaking. The introduction of multiple torque control units is used to control gear shifting, and the operability and flexibility are higher.

It should be understood that, in the drawings, although various steps are shown in sequence according to the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in Figure 1 may include multiple sub-steps or multiple stages, these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, and the execution order is not necessarily performed sequentially, but may be performed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

Through the above description of the implementation manners, those skilled in the art can clearly understand that the embodiments of the present invention can be implemented by hardware, or by means of software plus a necessary general hardware platform. Based on this understanding, the technical solutions of the embodiments of the present invention can be embodied in the form of software products, which can be stored in a non-volatile storage medium (which can be CD-ROM, U disk, mobile hard disk, etc.), Several instructions are included to enable a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in various implementation scenarios of the embodiments of the present invention.

The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the specific details in the above-mentioned embodiments. The above-mentioned embodiments and accompanying drawings are exemplary, and the modules or processes in the accompanying drawings are not necessarily What is necessary to implement the embodiments of the present invention should not be understood as a limitation of the present invention. Within the scope of the technical concept of the present invention, various simple modifications and combinations can be made to the technical solutions of the present invention. These simple modifications and combinations all belong to the scope of the present invention. protected range.

Claims

An upshift control method, characterized in that the upshift control method comprises the following steps:

S1: In the pre-charging stage, when the first brake and the second brake meet the preset conditions, the engine torque is reduced to the preset torque, and the clutch C0 adjusts the pressure according to the engine torque demand;

S2: In the torque stage, the first brake is reduced to the first torque, the second brake is increased to the second torque, and the torque of the drive motor works according to a preset strategy;

S3: In the speed stage, the speed of the input shaft decreases to the speed of the target gear, the torque of the second brake increases, the torque of the driving motor increases, and the generator outputs a reverse torque;

S4: In the closing stage, the engine is synchronized with the input shaft speed of the drive motor, the first brake torque is reduced to zero, the second brake torque is added with a safety torque, the generator torque is adjusted to zero, and the engine The torque is controlled according to the current rotational speed, and the clutch C0 is locked according to the engine torque.
The upshift control method according to claim 1, characterized in that step S3 comprises: triggering the clutch C0 slipping mechanism when it is detected that the dual-mass flywheel is about to have a super-current value torque, and the clutch C0 performs slipping Mount control.
The upshift control method according to claim 1, wherein the preset conditions include: the second brake performs a pre-filling action to adjust the torque to the first torque, and the first brake reduces the torque to the second torque.
The upshift control method according to claim 1, wherein the preset strategy is an external characteristic strategy.
The upshift control method according to claim 1, characterized in that before step S1, it comprises: when the throttle opening is greater than a set throttle opening threshold and the power downshift will not be triggered in the current gear, determining the trigger power Upshift control, otherwise continue to judge whether to trigger power upshift control.
The upshift control method according to claim 1, characterized in that step S2 comprises: the generator torque is zero, and the engine maintains the preset torque.
The upshift control method according to claim 1, characterized in that step S3 further comprises: the first brake maintains the first torque, and the engine maintains the preset torque.