Hybrid Vehicle Gear Shift Torque Fluctuation Control
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Solution Overview
Problem
Hybrid vehicles face challenges in minimizing torque fluctuation and maintaining fuel efficiency during gear shifts due to limitations in current control methods, which result in reduced engine output and passenger discomfort.
Innovation Solution
A control method that predicts the gear shift time point and intervention amount, reducing engine torque and increasing motor torque accordingly to minimize torque fluctuation and maintain driving force, thereby enhancing gear shift efficiency and drivability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If engine torque is reduced during gear shift intervention control, then gear shift smoothness is improved, but driving force is reduced causing passenger discomfort
Solution Approach 1:
The patent uses the motor as an intermediary component to compensate for the torque reduction during gear shift. When the engine torque is reduced for smooth gear shift, the motor provides compensating torque to maintain the total driving force, thereby resolving the contradiction between gear shift smoothness and driving force maintenance
Solution Approach 2:
The patent dynamically changes the torque parameters of both engine and motor during gear shift based on real-time operating conditions. The engine torque is reduced according to a calculated intervention amount, while the motor torque is simultaneously adjusted to compensate, maintaining overall driving force while enabling smooth gear transition
2Reliability
If air flow control is used to adjust engine torque, then ignition efficiency is enhanced, but torque fluctuation responsiveness is limited
Solution Approach 1:
The patent performs preliminary calculation of the gear shift intervention amount and predicted gear shift time point before actual gear shift occurs. This allows the engine torque to be reduced in advance with optimal air flow control, and the motor torque to be pre-positioned for compensation, thereby achieving both efficient ignition control and rapid torque response
Solution Approach 2:
The patent implements a feedback mechanism where the actual gear shift behavior and torque requirements are continuously monitored, and the air flow control and firing angle control are adjusted in real-time based on this feedback to optimize both ignition efficiency and torque responsiveness
3Speed
If firing angle control is used to achieve rapid torque reduction, then torque responsiveness is improved, but fuel efficiency is degraded
Solution Approach 1:
The patent calculates the optimal firing angle control strategy in advance based on the predicted gear shift time point and intervention amount. This preliminary action allows the engine to maintain efficient operation during normal phases while rapidly adjusting torque only when necessary for gear shift, minimizing fuel efficiency degradation
Solution Approach 2:
The patent applies firing angle control only partially - specifically during the brief period when gear shift intervention is required - rather than continuously. The motor compensates for torque during this partial period, allowing the engine to operate at optimal efficiency for the majority of the time while maintaining torque responsiveness when needed
Data Source
AI summary
A hybrid vehicle and a control method of gear shift therefor are provided. The hybrid vehicle and the control method of gear shift therefor minimize torque fluctuation during gear shift to enhance driving force and fuel efficiency. The method includes predicting a time point when gear shift occurs and estimating an intervention amount of the gear shift. Engine torque corresponding to the estimated intervention amount is then reduced up to the time point when the gear shift occurs and motor torque corresponding to the reduced engine torque is increased up to the time point when the gear shift occurs.