Control method, system and device for stable gear shifting of hybrid electric vehicle

Abstract

The invention discloses a control method, system and device for stable gear shifting of a hybrid electric vehicle. The hybrid electric vehicle comprises an engine, a motor and a double-clutch gearbox.The method comprises steps that when the vehicle is in a preset working condition, receiving a gear shifting request; obtaining a first output torque and a target output torque of the motor accordingto the gear shifting request; controlling the engine for being combined with the double-clutch gearbox, and unloading the output torque of the motor to zero from the first output torque; calculatinga first slope; controlling the output torque of the engine for being loaded from zero to the second output torque based on the first slope; controlling the output torque of the motor for being loadedfrom zero to the target output torque, moreover, controlling the output torque of the engine for being unloaded from the second output torque to zero based on the first slope. The method is advantagedin that the change of the output torque of the engine is controlled according to the change of the torque of the motor, the stable deceleration feeling of the whole vehicle is maintained, the acceleration fluctuation caused by torque loss during gear shifting is reduced, and smoothness during gear shifting is further improved.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to a control method, system and device for smooth shifting of a hybrid electric vehicle. Background technique [0002] With the improvement of living standards, the number of car ownership is increasing. Under the background of new energy constraints and environmental pollution, new energy vehicles represented by electric vehicles stand out and become the first choice of many people. [0003] Electric vehicles are driven by electric energy. However, during the braking process of the vehicle, the kinetic energy of the vehicle will be converted into heat through friction and consumed, resulting in a large amount of energy being wasted. According to relevant research data, under several typical urban working conditions, the energy consumed by friction braking during braking accounts for about 50% of the total driving energy of the vehicle. Electric vehicle braking energy recovery...

AI Technical Summary

Problems solved by technology

[0004] For reasons such as environmental protection and energy saving, hybrid vehicles have been more and more widely recognized and used by countries all over the world. In the prior art, due to the physical characteristics of traditional transmissions, the transmission ratio of the engine changes during gear shifting, resulting in gear shifting. During the process, the torque transmitted to the wheel ends decreases, resulting in fluctuations in acceleration

Especially when shifting gears in low gear, the transmission ratio changes greatly, and the corresponding wheel end torque loss is also large, resulting in uneven gear shifting, which in turn affects the driving stability of hybrid electric vehicles; traditional hybrid electric vehicles have a variety of hybrid structures , P2.5 structure hybrid vehicles are widely used, but when P2.5 structure hybrid vehicles are in the state of pure electric coasting, the motor recovers part of the kinetic energy to control the vehicle deceleration, but if the motor shifts gears, the motor torque needs to be first Unload to zero and then reload. At this time, the whole vehicle will lose the feeling of deceleration, and the illusion of sudden acceleration will appear.

Images