Coordinated control method for hydraulic type hybrid electric vehicle engine start-up process

Abstract

The invention discloses a coordinated control method for a hydraulic type hybrid electric vehicle engine start-up process. The method aims at a vehicle impact phenomenon caused by control logic difference and output torque changes in different modes during the mode switching in the engine start-up process, a dynamic model of a power system and the relationship between a vehicle impact degree and torque change rates of all power sources are established, the method of 'steady-state control + slope limit' of an engine / the hydraulic system torque variation limit revision of a hydraulic pump / motorbased on 'coordinated control of torque change rates of all power sources' is adopted, and according to a mutually coordinate quantitative limit of an impact degree target to the torque change rates of all power sources, the start-up process is coordinately controlled. According to the coordinated control method for the hydraulic type hybrid electric vehicle engine start-up process, the impact degree is analyzed based on a vehicle dynamic model, the system total output torque fluctuation caused by the change of the control logic and torque distribution mode before and after the switching of adriving mode, and the driving smoothness of the hydraulic type hybrid electric vehicle engine start-up process is ensured.

Description

technical field [0001] The invention belongs to the technical field of hybrid electric vehicles, and in particular relates to a method for coordinated control of the starting process of a hydraulic hybrid electric vehicle engine. Background technique [0002] At present, under the background of increasing pressure on energy and the environment, the development of low-carbon and environmentally friendly new energy vehicles has become the focus of social attention. Among them, planetary hybrid vehicles have become a new trend due to their good fuel economy and low emissions. One of the popular directions of energy vehicles. Among them, the planetary gear transmission coupling system equipped on commercial vehicles such as urban buses, the engine undergoes three dynamic processes from free state, passive speed up to active rotation and power output, and the corresponding pump / motor A state will also change rapidly. Due to the complex and changeable engine response characterist...

AI Technical Summary

Problems solved by technology

[0004] The engine startup coordination control method proposed in the above-mentioned patents is only applicable to specific power system configurations, and cannot well meet the control requirements of the engine startup process of hydraulic hybrid electric vehicles. Therefore, it is necessary to propose a method for hydraulic hybrid electric vehicles Coordinated control method for engine starting process

Images