Hybrid Vehicle Gear Shift Torque Control
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Solution Overview
Problem
Hybrid vehicles experience interruptions in driving torque transmission during gear shifts due to the opening position of the servo-assisted clutch, leading to perceived reductions in vehicle acceleration, which existing control methods struggle to mitigate effectively.
Innovation Solution
A method for controlling a hybrid vehicle during gear shifts by using a control unit to manage the reversible electrical machine and internal combustion engine, ensuring seamless acceleration profiles through optimal energy delivery from the battery, either by generating supplementary torque or regenerative braking, while maintaining the charge state and satisfying electrical loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the servo-assisted clutch is opened during gear shift, then the gear shift can be performed, but the transmission of driving torque is interrupted causing perceived reduction in vehicle acceleration
Solution Approach 1:
The reversible electrical machine acts as an intermediary device between the internal combustion engine and the drive wheels. During gear shift when the servo-assisted clutch is open and torque transmission is interrupted, the electrical machine provides compensating torque to maintain continuous drive torque delivery, thereby masking the interruption from the driver while allowing the gear shift to proceed
2Productivity
If the electrical machine draws energy from storage system to generate driving torque, then engine replacement function is achieved, but the electrical machine is in unfavorable condition for other functions
Solution Approach 1:
The system dynamically adjusts the connection configuration of the reversible electrical machine based on operational requirements. The connection device allows switching between different connection states (input shaft connection for starting, layshaft connection for torque compensation), enabling the electrical machine to adapt its function dynamically rather than being fixed in a single operational mode
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method ensures a substantially negligible transient in torque delivery, optimizing fuel consumption, reducing emissions, and masking the torque interruption to the driver, making the gear shift phase transparent and reducing perceived acceleration reductions.
Implementation Method 1
the electrical machine draws energy from the storage system to generate a driving torque which is equivalent to the driving torque generated by the internal combustion engine
Implementation Method 2
the reversible electrical machine may function either as a motor by drawing electrical energy and generating mechanical work, or as a generator by drawing mechanical work and generating electrical energy
Data Source
Figure 1
AI summary
A method to control a hybrid vehicle which comprises the steps of recognizing an interruption in the transmission of driving torque (C) to the drive wheels during a gear shift due to the opening position of the servo-assisted clutch (6); determining an objective acceleration profile (Aobj) and calculating an objective driving/breaking torque (Cm_obj, Cf_obj) that is such as to ensure the achievement of the objective acceleration profile (Aobj) during the gear shift, and controlling the reversible electrical machine (14) so as to deliver to the drive wheels the objective driving/breaking torque (Cm_obj, Cf_obj) that is such as to ensure the achievement of the objective acceleration profile (Aobj) during the entire amount of time in which there is an interruption in the transmission of driving torque (C) to the drive wheels during a gear shift.