Shift control method for hybrid vehicle

Abstract

The present invention comprises a step of determining whether the transmission input torque is greater than or less than 0 at the end of the inertia phase; a step of determining whether the transmission input torque is within a predetermined first reference range if the transmission input torque is greater than 0; and a step of modifying the lower limit value of the anti-jerk torque applied to the transmission input torque to a predetermined lower limit value if the transmission input torque is within the first reference range.

Description

Technology Field

[0001] The present invention relates to transmission control of a hybrid vehicle. Background Technology

[0003] In a hybrid vehicle using the TMED (Transmission Mounted Electric Device) method, anti-jerk control is performed by applying an inverse phase torque to the rotational vibration with a motor to offset the rotational vibration of the powertrain, thereby offsetting the vibration components and ensuring smooth driving performance of the vehicle.

[0004] When shifting gears, anti-jerk control is temporarily suspended during the inertia phase, where the transmission input speed changes, and then resumed just before the inertia phase is completed.

[0005] At this time, the above anti-jerk control may be performed in a form where the transmission input torque fluctuates between a positive region and a negative region near zero, and such anti-jerk torque, along with the backlash of the powertrain, may instead cause inappropriate vibrations, thereby causing a sense of unfamiliarity in the powertrain.

[0007] The matters described as the background technology of the above invention are intended only to enhance understanding of the background of the invention and should not be construed as an acknowledgment that they constitute prior art already known to those skilled in the art. Prior art literature

[0008] (Patent Document 0001) KR 1020170067228 A The problem to be solved

[0009] The present invention enables the suppression of the occurrence of a dissonance in the powertrain caused by anti-jerk control and backlash during shifting of a hybrid vehicle, thereby ensuring a smoother shifting feel and drivability of the vehicle, and ultimately improving the marketability of the vehicle. means of solving the problem

[0011] The transmission control method of the hybrid vehicle according to the present invention for achieving the above-mentioned purpose is,

[0012] A step for determining whether the transmission input torque is greater than or less than zero at the end of the inertia phase;

[0013] If the above transmission input torque is greater than 0, a step of determining whether the above transmission input torque is within a predetermined first reference range;

[0014] If the above transmission input torque is within the above first reference range, a step of modifying the lower limit value of the anti-jerk torque applied to the above transmission input torque to a predetermined correction lower limit value;

[0015] It is characterized by being composed including

[0017] The above first reference range may be set to include a range of transmission input torque that is judged to have the potential to induce backlash vibrations by applying anti-jerk torque to the transmission input torque at the end of the downshift inertia phase.

[0019] The above first reference range consists of a range between the first lower limit torque and the first upper limit torque;

[0020] The first lower limit torque can be set to be greater than 0 and the first upper limit torque can be set to be greater than the first lower limit torque.

[0022] The above correction lower limit is the following formula,

[0023] MAX[(AJ Min Lmt - TmInTqAfItv), AJ MinTqBase]

[0024] Here,

[0025] AJ Min Lmt; Lower limit of input torque of a transmission with anti-jerk torque applied

[0026] TmInTqAfItv; Transmission input torque (after intervention)

[0027] AJ MinTqBase; lower limit of existing anti-jerk torque

[0028] It can be determined as.

[0030] The lower limit of the transmission input torque to which the above anti-jerk torque is applied can be set to a positive value.

[0032] The above steps are performed repeatedly;

[0033] During the repetitive execution of the above steps, if the transmission input torque decreases to a value less than a predetermined minimum reset torque of 0, the step of correcting the lower limit value of the anti-jerk torque may be omitted.

[0035] If the above transmission input torque is less than 0, a step of determining whether the above transmission input torque is within a predetermined second reference range;

[0036] If the above transmission input torque is within the above second reference range, a step of correcting the upper limit value of the anti-jerk torque applied to the above transmission input torque to a predetermined correction upper limit value;

[0037] It can be configured to include.

[0039] The above second standard range may be set to include a range of transmission input torque that is judged to have the potential to induce backlash vibrations by applying anti-jerk torque to the transmission input torque at the end of the upshift inertia phase.

[0041] The above second reference range consists of a range between the second lower limit torque and the second upper limit torque;

[0042] The second upper limit torque may be set to be less than 0, and the second lower limit torque may be set to be less than the second upper limit torque.

[0044] The above correction upper limit is the following formula,

[0045] MIN[(AJ Max Lmt - TmInTqAfItv), AJ MaxTqBase]

[0046] Here,

[0047] AJ Max Lmt; Upper limit of input torque for transmission with anti-jerk torque applied

[0048] TmInTqAfItv; Transmission input torque (after intervention)

[0049] AJ MinTqBase; upper limit of existing anti-jerk torque

[0050] It can be determined as.

[0052] The upper limit of the transmission input torque to which the above anti-jerk torque is applied can be set to a negative value.

[0054] The above steps are performed repeatedly;

[0055] During the repetitive execution of the above steps, if the transmission input torque rises to a value greater than 0, exceeding a predetermined maximum reset torque, the step of correcting the upper limit of the anti-jerk torque may be omitted. Effects of the invention

[0057] The present invention enables the suppression of the occurrence of a dissonance in the powertrain caused by anti-jerk control and backlash during shifting of a hybrid vehicle, thereby ensuring a smoother shifting feel and drivability of the vehicle, and ultimately improving the marketability of the vehicle. Brief explanation of the drawing

[0059] FIG. 1 is a drawing illustrating a TMED-type hybrid powertrain to which the present invention can be applied. FIG. 2 is a flowchart illustrating an embodiment of a transmission control method for a hybrid vehicle according to the present invention. FIG. 3 is a graph illustrating the application of the present invention to a gear shifting situation before stopping during regenerative braking. Figure 4 is a graph illustrating the application of the present invention to a power-off upshift situation. Specific details for implementing the invention

[0060] Specific structural or functional descriptions of embodiments of the present invention disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the present invention, and embodiments according to the present invention may be implemented in various forms and should not be interpreted as being limited to the embodiments described in this specification or application.

[0061] Since embodiments according to the present invention may be subject to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention.

[0062] Terms such as "first" and / or "second" may be used to describe various components, but said components shall not be limited by said terms. For the sole purpose of distinguishing one component from another, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0063] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions describing the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0064] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0065] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0066] The present invention will be described in detail below by explaining preferred embodiments of the invention with reference to the attached drawings. Identical reference numerals in each drawing indicate identical components.

[0068] FIG. 1 illustrates a TMED type hybrid powertrain to which the present invention can be applied, wherein the power of the engine (E) is transmitted to the transmission (TM) through the engine clutch (EC), and the motor (M) is connected to the transmission input shaft.

[0069] Accordingly, the power of the engine (E) is transmitted to the transmission (TM) only when the engine clutch (EC) is engaged, and the power of the motor (M) can be supplied to the transmission input shaft at all times.

[0070] The power shifted through the above transmission (TM) is transmitted to the drive wheel (W) to enable the vehicle to be driven.

[0071] The engine (E) is controlled by an ECU (Engine Control Unit), the motor (M) is controlled by an MCU (Motor Control Unit), and the transmission (TM) is controlled by a TCU (Transmission Control Unit). The TCU is configured to communicate with the ECU and the MCU, and as described below, the TCU can request an intervention from the ECU and the MCU to limit the transmission input torque.

[0072] For reference, the ECU, MCU, and TCU mentioned above may be configured in various combinations that are integrated or separated from each other, and the configuration of Fig. 1 is merely an example.

[0074] Referring to FIG. 2, an embodiment of the transmission control method of a hybrid vehicle according to the present invention comprises: a step (S10) of determining whether a transmission input torque is greater than or less than 0 at the end of an inertia phase; a step (S20) of determining whether the transmission input torque is within a predetermined first reference range if the transmission input torque is greater than 0; and a step (S30) of modifying a lower limit value of an anti-jerk torque applied to the transmission input torque to a predetermined corrected lower limit value if the transmission input torque is within the first reference range.

[0075] The method comprises: a step (S40) of determining whether the transmission input torque is within a predetermined second reference range if the transmission input torque is less than 0; and a step (S50) of correcting the upper limit value of the anti-jerk torque applied to the transmission input torque to a predetermined upper limit value if the transmission input torque is within the second reference range.

[0076] That is, the embodiment of the present invention distinguishes a control method based on whether the transmission input torque input to the transmission at the end of the inertia phase is greater than or less than 0, and if the transmission input torque is greater than 0 and within the first reference range, the lower limit value of the anti-jerk torque is modified to the corrected lower limit value, and if the transmission input torque is less than 0 and within the second reference range, the upper limit value of the anti-jerk torque is modified to the corrected upper limit value.

[0077] Here, the lower correction limit is set to a level slightly higher than 0 as exemplified in FIG. 3 so that the transmission input torque with the anti-jerk torque applied does not decrease to 0 or lower, and the upper correction limit is set to a level slightly lower than 0 as exemplified in FIG. 4 so that the transmission input torque with the anti-jerk torque applied does not increase to 0 or higher.

[0078] Therefore, the present invention prevents the phenomenon in which, in the past, the transmission input torque fluctuated between positive and negative regions near zero due to anti-jerk control, thereby causing inappropriate vibration in the powertrain and creating a sense of unfamiliarity.

[0080] For reference, in the gear shifting process consisting of a torque phase and an inertia phase as described above, if the transmission input torque is greater than 0 at the end of the inertia phase, it may be a gear shifting situation before stopping during regenerative braking in which the driver operates the accelerator pedal to shift to a lower gear as shown in FIG. 3.

[0081] In addition, at the end of the inertia phase, if the transmission input torque is less than 0, it may be a Power Off Upshift situation in which the transmission shifts to a higher gear as the driver takes their foot off the accelerator pedal, as shown in FIG. 4.

[0082] That is, in the present invention, when the driver presses the accelerator pedal in a situation before stopping during regenerative braking, if the transmission input torque is within the first reference range, the lower limit value of the anti-jerk torque is modified to the corrected lower limit value, thereby preventing the transmission input torque from fluctuating between a positive region and a negative region near zero.

[0083] In addition, in the situation at the end of the power-off upshift inertia phase, if the transmission input torque is within the second reference range, the upper limit value of the anti-jerk torque is modified to the upper limit value of the correction, thereby preventing the transmission input torque from fluctuating between the positive and negative regions near zero.

[0084] Therefore, it becomes possible to prevent the phenomenon where conventional anti-jerk torque, along with powertrain backlash, induces inappropriate vibrations in the powertrain, thereby causing a sense of unfamiliarity.

[0085] For reference, the term 'transmission input torque' here simply refers to the torque input to the transmission without the anti-jerk torque by the motor (M) being applied.

[0087] The above first reference range may be set to include a range of transmission input torque that is judged to have the potential to induce backlash vibrations by applying anti-jerk torque to the transmission input torque at the end of the downshift inertia phase.

[0088] Accordingly, the first reference range mentioned above can be set as a torque region where backlash vibration may be induced when anti-jerk torque is applied to the transmission input torque, based on numerous experiments and analyses in accordance with the intent described above.

[0089] At this time, the first reference range is formed as a range between the first lower limit torque and the first upper limit torque; the first lower limit torque is set to be greater than 0 and the first upper limit torque is set to be greater than the first lower limit torque to form the first reference range.

[0091] The above correction lower limit is the following formula,

[0092] MAX[(AJ Min Lmt - TmInTqAfItv), AJ MinTqBase]

[0093] Here,

[0094] AJ Min Lmt; Lower limit of input torque of a transmission with anti-jerk torque applied

[0095] TmInTqAfItv; Transmission input torque (after intervention)

[0096] AJ MinTqBase; lower limit of existing anti-jerk torque

[0097] It can be determined as.

[0099] Here, the lower limit value (AJ Min Lmt) of the transmission input torque to which the anti-jerk torque is applied is set to a positive value. Since it is desirable to ensure that the anti-jerk torque is not restricted as much as possible within the range where the transmission input torque to which the anti-jerk torque is applied does not become 0 or less, it is desirable to set it to a level slightly higher than 0. This value can be determined design-wise through numerous experiments and analyses, and for example, it may be set to 5N.

[0100] In addition, the above intervention is such that the TCU requests the ECU and MCU to limit the transmission input torque for smoother and more fluid shifting, and accordingly, the transmission input torque is limited. For example, in FIG. 3, the transmission input torque is limited to a range below the intervention torque, and in FIG. 4, the transmission input torque is limited to a range above the intervention torque.

[0102] The steps of comparing the transmission input torque with 0 (S10), determining whether the transmission input torque is within the first reference range (S20), and modifying the lower limit value of the anti-jerk torque to the corrected lower limit value (S30) are performed repeatedly as the transmission progresses; and during the repeated performance of the steps, if the transmission input torque drops below a predetermined minimum reset torque less than 0 (S60), the step of correcting the lower limit value of the anti-jerk torque (S30) is omitted.

[0103] That is, while repeatedly performing the above steps during gear shifting and updating the correction lower limit value, if the driver suddenly releases the accelerator pedal and the transmission input torque drops below the minimum reset torque, the step (S30) of modifying the lower limit value of the anti-jerk torque to the correction lower limit value is omitted so that the original anti-jerk torque is applied to the transmission input torque as is, thereby allowing the original anti-jerk control to be performed smoothly.

[0104] Therefore, it is desirable to set the minimum reset torque by considering a level that can detect the driver's release of the accelerator pedal as described above, or a level where it is judged to be more advantageous to allow it as originally intended without restricting anti-jerk control as described above, and it can be determined design-wise through numerous experiments and analyses, so it is desirable to set it to a value slightly less than 0.

[0106] Meanwhile, in the step (S10) of determining whether the transmission input torque is greater than or less than 0, if the transmission input torque is less than 0, the step (S40) of determining whether the transmission input torque is within a predetermined second reference range; and if the transmission input torque is within the second reference range, the step (S50) of correcting the upper limit value of the anti-jerk torque applied to the transmission input torque to a predetermined correction upper limit value is performed.

[0107] That is, as described above, when the transmission input torque is less than 0 at the end of the inertia phase, it may be a Power Off Upshift situation in which the transmission shifts to a higher gear as the driver takes their foot off the accelerator pedal, as illustrated in FIG. 4. In such a situation, if the transmission input torque is within the second reference range, the upper limit of the anti-jerk torque is modified to the correction upper limit value, so that the transmission input torque with the applied anti-jerk torque ultimately remains only within the negative range and does not fluctuate between the positive range as in the past, thereby preventing the occurrence of a strange sensation in the powertrain.

[0109] The above second standard range may be set to include a range of transmission input torque that is judged to have a possibility of causing backlash vibrations by applying anti-jerk torque to the transmission input torque at the end of the power-off upshift inertia phase.

[0110] Accordingly, the second reference range mentioned above can be set as a torque region where backlash vibration may be induced when anti-jerk torque is applied to the transmission input torque, based on numerous experiments and analyses in accordance with the intent described above.

[0111] At this time, the second reference range is formed as a range between the second lower limit torque and the second upper limit torque; the second upper limit torque is set to be less than 0 and the second lower limit torque is set to be less than the second upper limit torque to form the second reference range.

[0113] The above correction upper limit is the following formula,

[0114] MIN[(AJ Max Lmt - TmInTqAfItv), AJ MaxTqBase]

[0115] Here,

[0116] AJ Max Lmt; Upper limit of input torque for transmission with anti-jerk torque applied

[0117] TmInTqAfItv; Transmission input torque (after intervention)

[0118] AJ MinTqBase; upper limit of existing anti-jerk torque

[0119] It can be determined as.

[0121] Here, the upper limit of the transmission input torque to which the anti-jerk torque is applied is set to a negative value, and since it is desirable to ensure that the anti-jerk torque is not restricted as much as possible within the range where the transmission input torque to which the anti-jerk torque is applied does not become 0 or higher, it is desirable to set it to a level slightly lower than 0, and this can be determined design-wise through multiple experiments and analyses.

[0123] The steps of comparing the transmission input torque with 0 (S10), determining whether the transmission input torque is within the second reference range (S40), and modifying the upper limit of the anti-jerk torque to the correction upper limit (S50) are performed repeatedly as the transmission progresses; and during the repeated performance of the steps, if the transmission input torque rises to a predetermined maximum reset torque greater than 0 (S70), the step of correcting the upper limit of the anti-jerk torque (S50) is omitted.

[0124] That is, while repeatedly performing the above steps during gear shifting and updating the correction upper limit value, if the driver suddenly presses the accelerator pedal and the transmission input torque rises to exceed the maximum reset torque, the step (S50) of modifying the upper limit value of the anti-jerk torque to the correction upper limit value is omitted so that the original anti-jerk torque is applied to the transmission input torque as is, thereby allowing the original anti-jerk control to be performed smoothly.

[0125] Therefore, it is desirable to set the maximum reset torque by considering a level at which the driver's operation of the accelerator pedal, etc., can be detected as described above, or a level at which it is judged that it is more advantageous to allow it as originally intended without restricting anti-jerk control as described above, and since it can be determined design-wise through numerous experiments and analyses, it is desirable to set it to a value slightly greater than 0.

[0127] Although the present invention has been illustrated and described in relation to specific embodiments, it will be obvious to those skilled in the art that the present invention can be modified and changed in various ways without departing from the technical spirit of the invention as provided by the following claims. Explanation of the symbols

[0128] E; Engine EC; Engine clutch TM; transmission M; Motor W; Drive wheel

Claims

Claim 1 A transmission control method for a hybrid vehicle, characterized by comprising: a step of determining whether the transmission input torque is greater than or less than zero at the end of the inertia phase; a step of determining whether the transmission input torque is within a predetermined first reference range if the transmission input torque is greater than zero; and a step of modifying the lower limit value of the anti-jerk torque applied to the transmission input torque to a predetermined lower limit value if the transmission input torque is within the first reference range. Claim 2 A transmission control method for a hybrid vehicle according to claim 1, wherein the first reference range is set to include a range of transmission input torque that is determined to have the potential to induce backlash vibration by applying anti-jerk torque to the transmission input torque at the end of the downshift inertia phase. Claim 3 A transmission control method for a hybrid vehicle according to claim 2, wherein the first reference range is a range between a first lower limit torque and a first upper limit torque; and wherein the first lower limit torque is greater than 0 and the first upper limit torque is set to be greater than the first lower limit torque. Claim 4 A method for controlling the transmission of a hybrid vehicle according to claim 1, wherein the correction lower limit value is determined by the following formula, MAX[(AJ Min Lmt - TmInTqAfItv), AJ MinTqBase], where AJ Min Lmt is the lower limit value of the transmission input torque to which anti-jerk torque is applied, TmInTqAfItv is the transmission input torque (after intervention), and AJ MinTqBase is the lower limit value of the existing anti-jerk torque. Claim 5 A transmission control method for a hybrid vehicle according to claim 4, characterized in that the lower limit value of the transmission input torque to which the anti-jerk torque is applied is set to a positive value. Claim 6 A transmission control method for a hybrid vehicle according to claim 1, wherein the steps are performed repeatedly; and during the repeated performance of the steps, if the transmission input torque decreases to less than a predetermined minimum reset torque less than 0, the step of correcting the lower limit value of the anti-jerk torque is omitted. Claim 7 A transmission control method for a hybrid vehicle according to claim 1, characterized by comprising: a step of determining whether the transmission input torque is within a predetermined second reference range if the transmission input torque is less than 0; and a step of correcting the upper limit value of the anti-jerk torque applied to the transmission input torque to a predetermined upper limit value if the transmission input torque is within the second reference range. Claim 8 A transmission control method for a hybrid vehicle according to claim 7, wherein the second reference range is set to include a range of transmission input torque that is judged to have the potential to induce backlash vibration by applying anti-jerk torque to the transmission input torque at the end of the upshift inertia phase. Claim 9 A transmission control method for a hybrid vehicle according to claim 8, wherein the second reference range is a range between a second lower limit torque and a second upper limit torque; and wherein the second upper limit torque is less than 0 and the second lower limit torque is set to be less than the second upper limit torque. Claim 10 A method for controlling the transmission of a hybrid vehicle according to claim 7, wherein the correction upper limit value is determined by the following formula, MIN[(AJ Max Lmt - TmInTqAfItv), AJ MaxTqBase], where AJ Max Lmt is the upper limit value of the transmission input torque to which anti-jerk torque is applied, TmInTqAfItv is the transmission input torque (after intervention), and AJ MinTqBase is the upper limit value of the existing anti-jerk torque. Claim 11 A transmission control method for a hybrid vehicle according to claim 10, characterized in that the upper limit of the transmission input torque to which the anti-jerk torque is applied is set to a negative value. Claim 12 A transmission control method for a hybrid vehicle according to claim 7, wherein the steps are performed repeatedly; and during the repeated performance of the steps, if the transmission input torque rises to a value exceeding a predetermined maximum reset torque greater than 0, the step of correcting the upper limit value of the anti-jerk torque is omitted.

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