Hybrid Control Unit Motor Torque Compensation for AMT Shift Shock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid electric vehicles (HEVs) equipped with P3-type automated manual transmissions (AMTs) experience shift delay and shift shock due to engine torque disconnection, causing discomfort for drivers.
Innovation Solution
A hybrid electric vehicle system that includes a hybrid control unit (HCU) and a transmission control unit (TCU) to intervene and compensate motor torque by reducing engine torque during predetermined shift phases, using pre-stored control maps to adjust motor torque and improve gear shift quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the single clutch of the transmission is disengaged to shift gear, then gear shifting is enabled, but shift delay and shift shock occur due to engine torque disconnection
Solution Approach 1:
The motor acts as an intermediary to compensate for the torque disconnection caused by clutch disengagement. The motor torque intervention fills the torque gap during the shift phase, preventing shift shock and delay while allowing the clutch to disengage for gear shifting.
Solution Approach 2:
The motor torque compensation is applied in advance during the predetermined shift phase before the clutch fully disengages. By anticipating the torque drop and compensating proactively, the system prevents shift shock and maintains smooth power delivery throughout the shifting process.
2Reliability
If motor torque intervention is applied during shift phase, then shift shock is reduced, but system complexity increases due to additional control mechanisms
Solution Approach 1:
The motor serves multiple functions: it provides propulsion during normal operation and acts as a torque compensation device during shifting. This multi-functionality allows the system to improve shift quality without adding dedicated compensation hardware, thereby limiting the increase in system complexity.
Solution Approach 2:
The HCU monitors the shift phase and clutch status in real-time, dynamically adjusting motor torque based on feedback from the transmission system. This closed-loop control enables precise torque compensation while maintaining system simplicity through intelligent coordination of existing components.
Data Source
AI summary
A hybrid electric vehicle and a method for compensating a motor torque thereof, may include a hybrid control unit (HCU) including a processor and a non-transitory storage medium containing instructions executed by the processor. The processor is configured to start motor torque intervention upon entering a predetermined shift phase during shifting, to determine a motor torque compensation amount by reflecting engine torque according to engine torque reduction control, and to perform motor torque compensation control based on the motor torque compensation amount.