KR101583991B1 - Method for Shift Torque Credibility Gap Compensation of Hybrid Vehicle - Google Patents

Abstract

The present invention relates to a method for shift torque credibility gap compensation of a hybrid vehicle, including: generating a reference torque profile (Tdes) from the torque reduction slope reflecting shift phase for the start/end of shift and the time difference of shift from the targeted gear data after calculating DCT output torque (Tout) of DCT (Double Clutch Transmission) mounted on a front wheel; and controlling a motor mounted on a rear wheel by motor torque (Tmotor) at the time of shifting to the targeted gear after calculating the motor torque (Tmotor) from the difference between DCT output torque (Tout) and the reference torque profile (Tdes). The method of the present invention allows accurate compensation for the torque difference between the reference torque and the actual shift torque by reflecting a shift phase, and prevents the shift credibility gap due to the difference in torque during shifting.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shift torque compensation method for a hybrid vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle, and more particularly, to a hybrid vehicle in which a method of compensating for torque discontinuity that occurs during shifting of DCT (Double Clutch Transmission) is implemented.

Generally, a hybrid vehicle (or a hybrid electric vehicle) is classified into a TMED (Transmission Mounted Electric Device), an FMED (Friedheel Mounted Electric Device), an Electric-Continuously Variable Transmission (E-CVT) , TTR (Through The Road) similar to E-4WD, and the TMED and FMED are types in which a motor is mounted in a conventional multi-stage transmission, the E-CVT is a planetary gear system, The 4WD is a system utilizing a continuously variable transmission or a multi-stage transmission, and the TTR is a system in which DCT is mounted on the front wheels.

Generally, the DCT has a characteristic that the torque transmitted to the wheels changes during shifting, so that the TTR hybrid vehicle must be able to compensate for the torque disconnection or decay phenomenon during the shift of the DCT. To this end, the TTR hybrid vehicle is similar to the e-4WD (Electric 4Wheel Drive) type, and the motor disposed on the rear wheel has a degree of freedom with respect to the DCT mounted on the front wheels. Thus, torque cutoff or attenuation Compensate for the phenomenon.

Specifically, in the motor torque control method, the transmission torque of the DCT input side Even / Odd Clutch is used to grasp the type of torque cutoff transmitted to the wheels during the DTC shift, and the gear shift ratio of the target gear stage and the target gear stage A reference torque profile is generated at the time of shifting and a control is performed so that the motor compensates the difference between the reference torque profile and the torque type transmitted to the wheels upon shifting.

Korean Patent Publication 10-2014-0073305 (June 16, 2014)

However, the above-described motor torque control method does not reflect the shift phase which is changed between the start and end of shifting in the generation of the reference torque profile, so that it is insufficient to accurately estimate the difference between the reference torque and the torque at the time of actual shifting And the torque discontinuity at the time of DTC shifting is continued to thereby cause the driver to have a limitation in feeling a smooth shifting texture.

In view of the above, the present invention is based on the fact that the shifting phase shift timing of a TTR hybrid vehicle mounted with a DCT on a front wheel is reflected to accurately compensate a difference between a reference torque and an actual shift torque, So as to provide a feeling of shifting texture.

In order to achieve the above object, there is provided a method for compensating for the speed shift disconnection of a hybrid vehicle, comprising the steps of: (A) shifting by a highest-level controller communicating with a transmission torque calculating unit that calculates a DCT output torque T _out of a DCT Collect target gear range information; (B) dividing the shift range of the target gear stage into a shift start and an end by using the output torque and the time diagram of the DCT, and outputting the shift range from the output torque and the time line to a shifting phase Shift Phase) is calculated; (C) calculating a shift time difference between the shift start time and the shift end time of the shift section in the shift phase, and generating a reference torque profile (T _des ) having a torque decay slope reflecting the shift time difference; (D) A motor torque (T _motor ) is calculated from the difference between the DCT output torque (T _out ) and the reference torque profile (T _des ), and the motor torque (T _motor ) Is controlled.

In (A), the transmission torque calculation unit continuously monitors each of the even clutch transmission torque and the odd clutch transmission torque of the DCT. The transmission torque calculating unit calculates the DCT output torque T _out by dividing the transmission torque by an even clutch transmission torque and an odd clutch transmission torque of the DCT.

The DCT is mounted on a front wheel, and the motor is mounted on a rear wheel.

The present invention accurately estimates and compensates for the difference between the reference torque at which the torque cut-off sensation of the TTR hybrid vehicle having the DCT transmission mounted on the front wheels occurs and the torque at the time of actual shifting, thereby compensating for the shift, There is an effect that can be.

FIG. 1 is a flow chart of a method for compensating a speed-torque disconnection of a hybrid vehicle according to the present invention, and FIG. 2 is a flowchart illustrating a method of compensating for the speed-torque disconnection of a hybrid vehicle according to the present invention, Yes.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the present invention. The present invention is not limited to these embodiments.

Fig. 1 shows a flowchart of a method of compensating for the speed shift disconnection of a hybrid vehicle according to the present embodiment. DCT (Double Clutch Transmission) controlled by the method of compensating for the shift torque disconnection is hereinafter referred to as an even clutch of the even speed change gears (2,4,6) and odd speed change gears (1,3,5) odd clutch.

As shown in the figure, the even / odd clutch transmission torque monitoring of S10 and the transmission output torque calculation of S20 are performed, so that the type of the DCT torque to be transmitted to the wheels at the time of DCT shifting is grasped. Then, when the shift start of S30 is determined, the information collection is performed in which the target gear position information collection in S40 and the shift phase in S50 are divided into a stepwise shift pattern. As a result, the reference torque profile at the time of shifting in S60 Control is performed so that the motor compensates for the difference between the reference torque profile and the torque type transmitted to the wheel at the time of shifting by making the calculation of the rear wheel motor compensation torque at S70.

Specifically, the even / odd clutch transmission torque monitoring of S10 is continuously performed through the transmission torque calculation unit, and the transmission torque calculation unit is divided into an even clutch transmission torque and an odd clutch transmission torque, Calculate each of the even clutch transmission torque and the odd clutch transmission torque. Further, the transmission torque calculation unit is in communication with a hybrid control unit (HCU), which is a highest level controller, and the HCU directly performs shift control of the DCT.

The transmission output torque calculation of S20 is performed in the HCU. To this end, the HCU uses the even clutch transmission torque and the odd clutch transmission torque provided by the transmission torque calculation unit as input information, and as a result, generates the DCT output torque T _out do. The DCT output torque T _out is a torque transmitted to a wheel in a DCT shift period and is calculated by Equation 1 as follows.

--- 수학식1

(1)

The output torque of the even-numbered gear stage is multiplied by the gear ratio of the even-numbered gear, the output torque of the odd-numbered gear stage is multiplied by the gear ratio of the odd-numbered gear, and the DCT output torque T _out Is calculated as the sum of the output torque of the even-numbered gear positions and the output torque of the odd-numbered gear positions.

Subsequently, when the shift start determination is made as in S30, the target gear position information is collected in S40. The shift start determination is determined by the current vehicle speed and the APS (Accel Pedal Scale or Accel Pedal Stroke) manipulated variable, and the HCU calculates the gear ratio of the target gear stage and the target gear stage by applying the present vehicle speed and APS to the mapping value having the reference value .

Subsequently, shift phase information is collected as in S50, and a reference torque profile of S60 is created. The shift phase information collection is performed through the target gear stage. The shift phase estimates the shift start and shift end times at which the shift progress estimated time is known, In a stepped shape separated by a time zone. Therefore, the reference torque profile T _des is determined by the torque attenuation slope with respect to the shift time difference between the start of the shift and the end of the shift, and the torque attenuation slope may reflect the shift phase of the divided stepwise , Which is calculated by the following equation (2).

--- 수학식2
여기서, 상기 LPF는 Low Pass Filter이고, 상기 T_initial은 변속이 시작되는 시점의 변속기 출력토크이며, 상기 T_final은 변속이 완료된 후의 변속기 출력토크이며, 상기 Phase는 변속진행과정의 시간에 따른 구분값으로 도 2의 변속페이즈패턴(5)이고, 상기 Current Phase value는 변속진행과정의 구분값 중 현재 구분값이며, 상기 Phase max value는 변속진행과정의 구분값중 최대 구분값이다.

- (2)
Herein, the LPF is a low pass filter, T _initial is a transmission output torque at a shift start time, T _final is a transmission output torque after a shift is completed, and Phase is a time- 2, the Current Phase value is the present differential value among the differential values in the shift progress process, and the Phase max value is the maximum differential value among the differential values in the shift progress process.

FIG. 2 shows the output torque and the time diagram from which Equation (2) is derived. As shown in the figure, in the output torque and the time line, the transmission section 1 can recognize the shift start and the shift end, and the transmission torque attenuation pattern 3 can know the torque decay in the shift section 1, The shift phase pattern 5 can know the stepwise movement in time that reaches the target speed change stage in the speed change section 1 and the reference torque profile 7 can recognize the stepwise movement of the shift speed pattern 5 in consideration of the subdivided step of the shift phase pattern 5 Is represented by the slope of the shifting section 1 as shown in FIG. Therefore, it can be seen that the reference torque profile 7 expressed in terms of the output torque and the time line is expressed by the reference torque profile T _{des in} Equation (2).

Next, as in S70, the rear wheel motor compensation torque calculation is performed, and as a result, the motor torque (T _motor ) is calculated by the following equation (3).

--- 수학식3
여기서, 상기 γ_{rear FGR}와 상기 γ_{front FGR}에서 FGR은 Final Gear Ratio이며, 상기 γ_{rear FGR}은 후륜쪽 Final Gear Ratio, 상기 γ_{front FGR}은 전륜쪽 Final Gear Ratio이다.

--- Equation 3
Here, _{FGR in} the γ _{rear FGR} and the γ _{front FGR} is a Final Gear Ratio, the γ _{rear FGR} is a Final Gear Ratio of a rear wheel, and the γ _{front FGR} is a Final Gear Ratio of a front wheel.

Equation 3 shows that the motor torque T _motor is calculated from the difference T _out -T _des between the DCT output torque T _out and the reference torque profile T _des . Therefore, the motor torque (T _motor ) can accurately estimate and compensate the difference between the reference torque that generates the torque disconnection during shifting and the torque at the time of actual shifting by considering the subdivided shifting phase pattern 5 of the shifting section 1 . Therefore, the driver feels a smooth shifting texture in which there is no difference between the reference torque at which the torque disconnection occurs during shifting and the torque at the time of actual shifting.

As described above, the method for compensating the speed torque disconnection of the hybrid vehicle according to the present embodiment is a method for compensating for the shift torque disconnection of the hybrid vehicle in which the DCT output torque T _out of the DCT mounted on the front wheels is calculated, The reference torque profile T _des is generated from the torque attenuation slope reflecting the shift phase and the shift time difference and the motor torque T _{motor is} calculated from the difference between the DCT output torque T _out and the reference torque profile T _des , And the motor mounted on the rear wheel is controlled by the motor torque (T _motor ) when the target gear speed change is performed, thereby accurately compensating the difference between the reference torque and the torque at the actual shift through the reflection of the shift phase.

1: Shift range 3: Shift torque attenuation pattern
5: Shift Phase Pattern
7: Reference torque profile

Claims (7)

(A) collecting target gear position information when a shift is made by a top-level controller communicating with a transmission torque calculating unit that calculates DCT output torque T _out of DCT (Double Clutch Transmission);
(B) dividing the shift range of the target gear stage into a shift start and an end by using the output torque and the time diagram of the DCT, and outputting the shift range from the output torque and the time line to a shifting phase Shift Phase) is calculated;
(C) calculating a shift time difference between the shift start time and the shift end time of the shift section in the shift phase, and generating a reference torque profile (T _des ) having a torque decay slope reflecting the shift time difference;
(D) A motor torque (T _motor ) is calculated from the difference between the DCT output torque (T _out ) and the reference torque profile (T _des ), and the motor torque (T _motor ) Controlled
Wherein the hybrid vehicle is a hybrid vehicle.
The method according to claim 1, wherein, in (A), the transmission torque calculation unit continuously monitors each of an even clutch transmission torque and an odd clutch transmission torque of the DCT.
The transmission torque calculation method according to claim 2, wherein the transmission torque calculation unit calculates the DCT output torque T _out by dividing the transmission torque by an even clutch transmission torque of the DCT and the transmission torque of the odd clutch .
The DC-DC converter according to claim 1, wherein the DCT output torque (T _out )

Of the vehicle is calculated by the following equation.
2. The method of claim 1, wherein in (C), the reference torque profile (T _des )

T _initial is a transmission output torque at the start of shifting, T _final is a transmission output torque after shifting is completed, and the Current Phase value is a shift speed Wherein the phase max value is a maximum value of the division values of the shift progress process.
2. The method according to claim 1, wherein, in (D), the motor torque (T _motor )

_Wherein the γ _{rear FGR} is a rear gear ratio of a rear wheel side, and the γ _{front FGR} is a front wheel side ratio of a front wheel side.
The method of claim 1, wherein the DCT is mounted on a front wheel, and the motor is mounted on a rear wheel.

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