Coordinated shift control method for planetary gear transmission coupling system of hydraulic hybrid vehicle

Abstract

The invention discloses a coordination control method for gear shifting of a planetary gear speed change coupling system of a hydraulic hybrid car. The method aims at the phenomenon that when a series-parallel type hydraulic hybrid car with a planetary gear speed change coupling device shifts gears, due to state change of a clutch / brake and a hydraulic pump / motor, impact is caused easily, a systemmechanical state space expression is set up by means of kinetic analysis, the approximate linear relation between system input torque and output torque during stages of gear shifting is obtained by means of coefficient matrix operation processing, then the coordination control law for ensuring stable output torque between the actuation opportunity of the clutch / brake and the oblique plate openingdegree change of the hydraulic pump / motor is determined in the gear shifting process, and finally the coordination control method between the oblique plate opening degree of the hydraulic pump / motorand the state of the clutch / brake is obtained. According to the method, based on the system mechanic relation, the influence of states of all the components of the system is analyzed and considered comprehensively, proper control between the hydraulic pump / motor and the clutch / brake can be achieved, and the gear shifting smoothness of the hybrid car is ensured.

Description

technical field [0001] The invention belongs to the technical field of hybrid electric vehicles, in particular to a shift coordination control method for a planetary gear transmission coupling system of a hydraulic hybrid electric vehicle. Background technique [0002] With the increasingly severe energy and environmental issues, energy-saving and new energy vehicle technologies have become hot spots. Due to its good economy and long driving range, hybrid electric vehicles have become one of the key research directions. Among them, the hybrid hybrid model can achieve double decoupling of engine speed and torque, and has good system dynamic characteristics, rich and diverse vehicle energy optimization control algorithms, and can ensure that the engine works in the high-efficiency area as much as possible, so fuel consumption is usually lower. Low, has been more development and application. [0003] Hybrid vehicles usually have multiple power sources, and each power source w...

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Problems solved by technology

For example, the Chinese patent announcement number is CN105752076B, and the announcement date is 2018-08-24, which discloses the shift speed regulation method of hybrid electric vehicles and the power system of hybrid electric vehicles. Torque control and motor speed control to shorten the shift time and reduce power interruption, but it cannot realize the coordinated shift control of the multi-clutch / brake transmission system; another example is the Chinese patent announcement number CN103158708B, and the announcement date is 2016-01-13 , discloses a shift control method for a hybrid electric vehicle with an AMT gearbox. This method needs to reduce the torque of the motor and the engine to zero when shifting gears and then perform shift control on the relevant gears, which will cause power interruption and affect driving. Take the experience; Another example is that the Chinese patent publication number is CN106671973A, and the publication date is 2017-05-17, which discloses a hybrid electric vehicle and its shift control method and shift control system. The shift control method proposed by the method only determines The reference factors and the control state of the clutch when the hybrid vehicle formulates the shift strategy under the four different working modes, but it does not explain the specific coordination control method between the torque of the hydraulic pump / motor and the clutch control state during the shift; another example The Chinese patent publication number is CN107985301A, and the publication date is 2018-05-04. It discloses a shift system and an upshift shift method based on a hybrid system. This method only takes the hydraulic pump / motor speed synchronization as the control target, and does not consider The influence of the torque of the motor on the system power and vehicle impact when the speed is adjusted, and the timing of the clutch engagement is only judged by the shift time and a fixed time threshold, without coordinated control between the clutch state and the motor torque, smooth shifting cannot be guaranteed sex

[0005] In summary, the above-mentioned existing shift coordination methods for hybrid electric vehicles are not aimed at hybrid electric vehicles using Lavigne-style planetary gear transmission coupling systems, nor are they based on detailed dynamics theory for multi-clutch / brake control during shifting. The detailed coordination control method between state and hydraulic pump / motor torque cannot better ensure the stability of system output torque and the smoothness of vehicle driving

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