Method and device for shifting gears of an automatic transmission vehicle

Abstract

The invention relates to the field of engines, and puts forward a gear shifting method and device for an automatic catch vehicle. The method comprises the following steps: in a gear shifting process,a gearbox controller is used for calculating a practical torque transmission ratio transferred by a clutch side according to the torque distribution of two clutches so as to send a practical torque transmission ratio to the engine controller. The engine controller obtains a wheel rim torque according to practical vehicle speed and an accelerator pedal position by table look-up, the wheel rim torque and the practical torque transmission ratio are combined to obtain a practical output torque, and the engine is controlled to output the practical output torque. In a gear shifting process, an original gear shifting strategy is changed, so that the practical torque transmission ratio calculated by the gearbox controller more conforms to real-time changes in a gear shifting process so as to guarantee stable vehicle acceleration in a gear shifting process, power failure feeling in the gear shifting process is eliminated, and gear shifting smoothness is improved.

Description

technical field [0001] The invention relates to the field of transmissions, in particular to a method and device for shifting gears of an automatic transmission vehicle. Background technique [0002] When the automatic transmission vehicle is driving, the vehicle will automatically select the appropriate gear according to the driving speed and traffic conditions, which brings convenience to people's driving and travel, and also increases the popularity of automatic transmission vehicles. The gearbox controller can calculate the torque transmission ratio during the gear shifting process under the design of the software, and the engine controller can obtain the wheel torque according to the torque transmission ratio, thereby controlling the speed change of the gearbox during the gear shifting process, and further controlling the engine's PTO. [0003] At present, people have higher and higher requirements for driving and comfort of automobiles, and the requirements for smooth...

AI Technical Summary

Problems solved by technology

For vehicles with automatic transmission, the smoothness of gear shifting is higher than that of vehicles with manual transmission, but if the acceleration stability during the gear shifting process cannot be guaranteed, there will still be a sense of power interruption.

In automatic transmission vehicles, there are generally many vehicles equipped with wet dual-clutch gearboxes. Due to the imperfect control strategy of the engine output torque during the gear shifting process, it affects the power output of the vehicle during the gear shifting process, causing the vehicle acceleration to decrease and cannot maintain the acceleration. The stability of the vehicle will eventually have an adverse effect on the smoothness of the vehicle's shifting

[0004] During the gear shifting process of a traditional model equipped with a wet dual-clutch gearbox, the control strategy in the prior art is to use the torque transmission ratio of the current gear as the torque transmission ratio during the gear shifting process, but the torque transmission ratio cannot accurately reflect the gear shifting Real-time changes in torque transmission ratio during the process

At the same time, the control strategy in the prior art obtains the required pedal torque during the engine gear shifting process by directly looking up the table, and calculates the required wheel torque in combination with the torque transmission ratio, which cannot guarantee that the vehicle wheel torque remains constant during the gear shifting process. Steady, resulting in a noticeable power interruption during gear changes

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