KR-102962193-B1 - Controlling Method for Gear Shift of the Electric Motion Vehicle

Abstract

The present invention relates to a transmission control method for an electrified vehicle, and more preferably, comprises the steps of determining whether the vehicle is EV driving, determining whether kickdown transmission is required during EV driving, determining whether acceleration linear control is possible when kickdown transmission is required, performing torque compensation of the motor when acceleration linear control is possible, and performing transmission shifting based on the compensated motor torque.

Inventors

• 장철호
• 권기영
• 한상준
• 박지현
• 정재윤
• 김민수
• 박정수
• 국재창
• 이민규

Assignees

• 현대자동차주식회사
• 기아 주식회사

Dates

Publication Date

20260508

Application Date

20201202

Claims (8)

1. Step for determining whether the vehicle is EV driving; A step for determining whether kickdown shifting is required during EV driving; A step of determining whether acceleration linear control is possible when kickdown shifting is required; If acceleration linear control is possible, a step of performing torque compensation of the motor; and The method includes the step of performing a gear shift of the transmission based on the above-mentioned compensated motor torque; In the step of determining whether acceleration linear control is possible when kickdown shifting is required, A step of determining whether a user's request for continuous acceleration linear control has been entered; A transmission control method for an electrified vehicle, further comprising the step of determining whether it is a transmission synchronizer section when an acceleration linear constant control request is input.
2. delete
3. In Article 1, In the step of determining whether acceleration linear control is possible when kickdown shifting is required, A step of determining whether a user's acceleration linear selection control request has been entered; A step of determining whether the motor operating point after shifting is in a derating section when an acceleration linear selection control request is input; and A transmission control method for an electrified vehicle, further comprising the step of determining whether the motor operating point after transmission is in a derating section, or whether it is in a transmission synchronizer section.
4. In Article 1, In the step of performing torque compensation for the above motor, A transmission control method for an electrified vehicle further comprising the step of calculating the final motor torque by multiplying the sum of the motor's derating torque and margin torque by a synchronization rate and adding it to the motor's torque command received from the control unit.
5. In Paragraph 4, A transmission control method for an electrified vehicle in which the motor derating torque is calculated as the difference between the motor torque before transmission and the motor torque after transmission.
6. In Paragraph 4, A shift control method for an electrified vehicle in which the synchronization rate is calculated as the ratio of the difference between the current motor RPM and the driving RPM before shifting to the difference between the target RPM after shifting and the driving RPM before shifting during shifting.
7. In Paragraph 4, A transmission control method for an electric vehicle in which the torque command of the above motor is a command stored in the above control unit.
8. In Article 1, In the step of determining whether a kickdown shift is required in EV driving mode, A transmission control method for an electrified vehicle further comprising the step of determining that a kickdown shift is required when the amount of accelerator pedal input is greater than or equal to a first reference value.

Description

Controlling Method for Gear Shift of the Electric Motion Vehicle The present invention relates to a transmission control method for an electric vehicle, and more preferably, to a transmission control method for an electric vehicle that performs compensation of motor torque during transmission in correspondence with motor torque before transmission and motor torque after transmission as a technique to prevent responsiveness delay due to a reduction in motor torque after performing kickdown transmission. With the constant demand for improved fuel efficiency and the tightening of emission regulations in various countries, the demand for eco-friendly vehicles is increasing, and hybrid electric vehicles (HEV/PHEV) are being offered as a realistic alternative. These hybrid vehicles can provide optimal output and torque depending on how the engine and motor are operated in harmony during the driving process using two power sources consisting of an engine and a motor. In particular, in hybrid vehicles employing a parallel type (or TMED: Transmission Mounted Electric Device) hybrid system equipped with an electric motor and an engine clutch (EC: Engine Clutch) between the engine and the transmission, the output of the engine and the motor can be simultaneously transmitted to the drive shaft. Figure 1 shows an example of the powertrain structure of a typical hybrid vehicle. Referring to FIG. 1, a power train of a hybrid vehicle employing a parallel type hybrid system is shown, in which an electric motor (or driving motor, 120) and an engine clutch (130) are installed between an internal combustion engine (ICE, 110) and a transmission (140). In such vehicles, generally, when the driver presses the accelerator after starting (i.e., the accelerator pedal sensor is on), the engine clutch (130) is open, and the motor (120) is driven first using the power from the battery, and the power from the motor is transmitted through the transmission (140) and the final drive (FD: Final Drive, 160) to move the wheels (i.e., EV mode). As the vehicle gradually accelerates and requires increasingly greater driving force, an auxiliary motor (or starter generator motor) is operated to drive the engine (110). Accordingly, when the rotational speeds of the engine (110) and the motor (120) become equal, the engine clutch (130) engages, and the engine (110) and the motor (120) drive the vehicle together. Additionally, the transmission (140) may be a multi-stage transmission or a multi-plate clutch, such as a dual-clutch transmission (DCT). The transmission (140) includes a clutch engaged with the engine (110) or motor (120), and can repeatedly engage and disengage the clutch to change the gear stage. However, when driving in EV mode, if a kickdown request is applied during the motor's equal power range, the motor's driving torque tends to decrease, and there was a problem in that RPM synchronization control during gear shifting was delayed, or responsiveness was delayed and G-drop phenomena occurred. Furthermore, as recent electrified vehicles, even in the case of electric vehicles including transmissions, problems such as transmission responsiveness delays of the aforementioned hybrid vehicles have continuously occurred. Figure 2 illustrates the problem of G drop and gear shift delay occurring when a kickdown request is applied in the equal power range of the motor as described above. Figure 1 illustrates the configuration of an electric vehicle. Figure 2 illustrates data on changes in the driving relationship during kickdown shifting as a conventional technology. FIG. 3 illustrates the configuration of a control unit that performs a transmission control method for an electric vehicle as an embodiment of the present invention. FIG. 4 illustrates a flowchart for performing a transmission control method for an electric vehicle as an embodiment of the present invention. Figure 5 illustrates, as an embodiment of the present invention, a graph of the shift synchronizer section of a shift control method for an electric vehicle. Figure 6 illustrates, as an embodiment of the present invention, a graph showing the change in driving relationship according to the transmission control method of an electric vehicle. Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be interpreted as being limited to the embodiments below. These embodiments are provided to more completely explain the present invention to those with average knowledge in the art. Additionally, terms such as "...part," "...unit," and "...module" described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software. Additionally, in this specification, 'EV mode' may be used as