Torque rise control method for power downshift of automatic transmission

Abstract

The invention discloses a torque increasing control method for power downshift of an automatic transmission, and belongs to the technical field of automatic transmissions. The method comprises the following steps: triggering torque increasing control: judging whether entering conditions are met or not according to an accelerator and torque; executing torque increasing control: on the basis of the current actual torque, increasing to a torque increasing target peak value at a first calibration slope; the torque increasing target peak value is kept until the rotating speed synchronization process of gear shifting starts; reducing the torque rise target peak value to 0 at a second calibration slope; and outputting the sum of the torque increasing absolute value and the target torque value to an execution module as a torque increasing request value. And compensating a torque increasing value. And the torque rise control is quitted. The rotating speed of the output shaft is stable in the gear shifting process, the vehicle speed is basically unchanged, impact is reduced, and driving smoothness is improved; power requirements are accurately matched, smooth power connection before and after gear shifting is guaranteed, and smoothness and power performance are both considered; and the torque increasing absolute value can be corrected in real time, torque waste is avoided, and the balance between the power performance and the fuel economy is assisted.

Description

Technical Field

[0001] The invention relates to a method for controlling torque increase during power downshifting of an automatic transmission, and belongs to the technical field of automatic transmissions. Background Art

[0002] Amidst the rapid development of the automotive industry, automatic transmissions are becoming increasingly common in vehicles due to their enhanced driving convenience and comfort. Customers are increasingly demanding higher levels of ride smoothness and power, driving both hardware improvements (such as transmission component upgrades) and the continuous optimization of intelligent adjustment technologies within electronic control units (TCUs). The TCUs in automatic transmissions monitor multiple parameters in real time, including vehicle speed, engine speed, and accelerator pedal position, using complex algorithms to optimize shifting logic.

[0003] Although the TCU can dynamically adjust the shift timing and gear position according to driving conditions, and to a certain extent help achieve a smoother driving experience, during the process of power downshifting when the accelerator is pressed, if the accelerator is suddenly released or the target torque drops below the preset value, the existing control logic is difficult to respond accurately, which can easily cause problems such as vehicle speed fluctuations during gear shifting and affected driving smoothness. It cannot fully meet users' demand for a high-quality driving experience. Therefore, it is urgent to improve the torque increase control strategy during the power downshifting process of the automatic transmission. Summary of the Invention

[0004] In order to solve the problems existing in the background technology, the present invention provides a method for controlling torque increase during power downshifting of an automatic transmission.

[0005] To achieve the above object, the present invention adopts the following technical solution: a method for controlling torque increase during power downshifting of an automatic transmission, the method comprising the following steps:

[0006] S1: Triggering torque increase control: judging whether the entry conditions are met based on the throttle and torque;

[0007] S2: execute torque increase control;

[0008] S201: Based on the current actual torque, the torque is increased to a target torque increase peak value at a first calibration slope;

[0009] S202: Maintaining the target torque increase peak value until the speed synchronization process of the gear shift begins;

[0010] S203: decreasing from the torque increase target peak to 0 at a second calibration slope;

[0011] S204: Outputting the sum of the torque increase absolute value and the target torque value as the torque increase request value to the execution module.

[0012] The method for determining the torque increase target peak value is: constructing a torque increase target peak value mapping relationship table and then adjusting the torque increase value until the output shaft speed change rate is stable so that the vehicle speed remains unchanged during the gear shifting process.

[0013] The torque increase target peak mapping relationship is as follows:

[0014]

[0015] Where:

[0016] The target peak value for torque increase;

[0017] is the current vehicle speed,

[0018] The target speed for the current gear and the target speed of the next gear The difference.

[0019] The first calibration slope and the second calibration slope are different calibration values.

[0020] S3: torque increase compensation;

[0021] The torque increase compensation calculation formula in S3 is as follows:

[0022]

[0023] Where:

[0024] is the compensation coefficient;

[0025] is the rate of change of output shaft speed;

[0026] when No compensation when When , positive compensation is performed, When , negative compensation is performed.

[0027] S4: Exit torque increase control.

[0028] The exit condition of the torque increase control in S4 is any of the following:

[0029] The absolute value of the torque increase decreases to 0 at a calibrated decreasing slope;

[0030] The driver steps on the accelerator again and the throttle opening or torque is greater than the preset value;

[0031] The system triggers torque reduction control.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention identifies in real time the special working condition of power downshifting when the accelerator is pressed, triggering torque increase, and executing torque increase in stages (increasing, maintaining, decreasing) with different slopes. Combined with dynamic compensation of the output shaft speed change rate, the output shaft speed is kept stable and the vehicle speed remains basically unchanged during gear shifting, thereby reducing impact and improving driving smoothness. The torque increase target peak is set as needed (inversely proportional to the target torque value when entering the torque increase, and is related to the vehicle speed and gear speed difference). The torque increase request value is dynamically superimposed to accurately match the power demand, ensuring smooth power connection before and after gear shifting, and taking into account both smoothness and power. The torque increase control exit conditions are rich and flexible, which can cope with various driving scenarios and user operations, and improve the intelligence and adaptability of vehicle control. The compensation mechanism based on the speed change rate can correct the absolute value of the torque increase in real time to avoid torque waste, help balance power and fuel economy, optimize the energy efficiency of the vehicle, and fully meet users' needs for high-quality driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a flow chart of the present invention;

[0035] Figure 2 It is a torque variation schematic curve diagram of the present invention. DETAILED DESCRIPTION

[0036] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] A method for controlling torque increase during power downshifting of an automatic transmission, the method comprising the following steps:

[0038] S1: Triggering torque increase control: judging whether the entry conditions are met based on the throttle and torque;

[0039] The TCU monitors the throttle opening and target torque changes in real time. When it detects that the throttle is suddenly released during a power downshift or the target torque drops below a preset value, torque increase control is triggered.

[0040] S2: execute torque increase control;

[0041] S201: Based on the current actual torque, the torque is increased to a target torque increase peak value at a first calibration slope, wherein the target torque increase peak value is inversely proportional to the target torque value when entering the torque increase control, i.e., the larger the target torque value when entering the torque increase control, the smaller the target torque increase peak value; and the smaller the target torque value when entering the torque increase control, the larger the target torque increase peak value;

[0042] The method for determining the torque increase target peak value is: after constructing a torque increase target peak value mapping relationship table, the torque increase value is adjusted until the output shaft speed change rate tends to be stable, so that the vehicle speed remains basically unchanged during the gear shifting process, and the vehicle speed begins to decrease after the gear shifting is completed.

[0043] The torque increase target peak mapping relationship is as follows:

[0044]

[0045] Where:

[0046] The target peak value for torque increase;

[0047] is the current vehicle speed,

[0048] The target speed for the current gear and the target speed of the next gear The difference.

[0049] like Figure 2 As shown, although the absolute value of the torque increase is very small at the final dotted line, the target torque is increasing, so the torque increase request value is increasing.

[0050] S202: Maintaining the target torque increase peak value until the speed synchronization process of the gear shift begins;

[0051] S203: decreasing from the torque increase target peak to 0 at a second calibration slope;

[0052] S204: Outputting the sum of the torque increase absolute value and the target torque value as the torque increase request value to the execution module.

[0053] The first calibration slope and the second calibration slope are different calibration values.

[0054] S3: torque increase compensation;

[0055] The torque increase compensation calculation formula in S3 is as follows:

[0056]

[0057] Where:

[0058] is the compensation coefficient;

[0059] is the rate of change of output shaft speed;

[0060] when No compensation when When , positive compensation is performed, When , negative compensation is performed.

[0061] S4: Exit torque increase control.

[0062] The exit condition of the torque increase control in S4 is any of the following:

[0063] The absolute value of the torque increase decreases to 0 at a calibrated decreasing slope;

[0064] The driver steps on the accelerator again and the throttle opening or torque is greater than the preset value;

[0065] The system triggers torque reduction control.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0067] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for increasing torque during power downshifting of an automatic transmission, characterized in that: The method comprises the following steps: S1: Triggering torque increase control: judging whether the entry conditions are met based on the throttle and torque; S2: execute torque increase control; S3: torque increase compensation; S4: Exit torque increase control.

2. The method for increasing torque during power downshifting of an automatic transmission according to claim 1, characterized in that: The S2 comprises the following steps: S201: Based on the current actual torque, the torque is increased to a target torque increase peak value at a first calibration slope; S202: Maintaining the target torque increase peak value until the speed synchronization process of the gear shift begins; S203: decreasing from the torque increase target peak to 0 at a second calibration slope; S204: Outputting the sum of the torque increase absolute value and the target torque value as the torque increase request value to the execution module.

3. The method for increasing torque during power downshifting of an automatic transmission according to claim 2, characterized in that: The method for determining the torque increase target peak value is: constructing a torque increase target peak value mapping relationship table and then adjusting the torque increase value until the output shaft speed change rate is stable so that the vehicle speed remains unchanged during the gear shifting process.

4. The method for controlling torque increase during power downshifting of an automatic transmission according to claim 3, characterized in that: The torque increase target peak mapping relationship is as follows: Where: The target peak value for torque increase; is the current vehicle speed, The target speed for the current gear and the target speed of the next gear The difference.

5. The method for controlling torque increase during power downshifting of an automatic transmission according to claim 4, characterized in that: The first calibration slope and the second calibration slope are different calibration values.

6. The method for increasing torque during power downshifting of an automatic transmission according to claim 1, characterized in that: The torque increase compensation calculation formula in S3 is as follows: Where: is the compensation coefficient; is the rate of change of output shaft speed; when No compensation when When , positive compensation is performed, When , negative compensation is performed.

7. The method for controlling torque increase during power downshifting of an automatic transmission according to claim 6, characterized in that: The exit condition of the torque increase control in S4 is any of the following: The absolute value of the torque increase decreases to 0 at a calibrated decreasing slope; The driver steps on the accelerator again and the throttle opening or torque is greater than the preset value; The system triggers torque reduction control.

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