Hybrid EV Motor Control for Combustion Stop Vibration Damping
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Solution Overview
Problem
Existing control devices for hybrid electric vehicles fail to sufficiently suppress vehicle body vibration during combustion stop processes due to torque fluctuations, despite compensating with a second rotary electric machine.
Innovation Solution
A control device that employs a combination of first and second rotary electric machines to generate vibration damping torques, adjusting their amplitudes based on engine speed, battery charging/discharging status, and temperature to effectively suppress vehicle body vibrations through multiple transmission paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If combustion stop process is performed to raise catalytic device temperature, then exhaust gas control efficiency is improved, but vehicle body vibration increases due to torque fluctuation
Solution Approach 1:
The control device generates vibration damping torque in the first rotary electric machine before and during the combustion stop process to counteract the torque fluctuation and vibration caused by stopping combustion in certain cylinders. This preliminary anti-action suppresses the transmission of vibration to the vehicle body while maintaining the exhaust gas control efficiency benefits of the combustion stop process
Solution Approach 2:
The first rotary electric machine acts as an intermediary between the engine and the drive shaft, generating vibration damping torque to filter out the harmful vibrations caused by combustion stop. This intermediary mechanism allows the combustion stop process to proceed for exhaust gas control while preventing vibration transmission to the vehicle body
2Power
If second rotary electric machine compensates torque decrease, then power output is maintained, but vehicle body vibration suppression is insufficient
Solution Approach 1:
The vibration damping function is segmented from the torque compensation function. The second rotary electric machine handles torque compensation to maintain power output, while the first rotary electric machine specifically handles vibration damping. This segmentation allows each component to optimize its function without compromise
Solution Approach 2:
The first rotary electric machine is introduced as a dedicated intermediary component for vibration damping, separate from the second rotary electric machine's torque compensation role. This additional intermediary enables effective vibration suppression while maintaining the power output benefits of torque compensation
3Object-affected harmful factors
If vibration damping torque amplitude is increased, then vehicle body vibration suppression is improved, but battery charging/discharging complexity increases
Solution Approach 1:
The control device dynamically adjusts the amplitude of vibration damping torque based on real-time engine operating conditions, including engine speed, acceleration requests, and battery state of charge. This dynamic adjustment optimizes vibration suppression effectiveness while adapting to varying power demands and battery conditions, reducing overall control complexity
Solution Approach 2:
The control device changes the operational parameters of the rotary electric machines based on engine speed and battery state. At different engine speeds and battery charge levels, the vibration damping torque amplitude and the torque compensation amount are adjusted to maintain optimal performance while simplifying control under specific operating conditions
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 control device enhances vehicle body vibration suppression by optimizing damping torques generated by both rotary electric machines, effectively reducing vibrations transmitted through engine mounts and drive shafts, while managing battery charging and discharging to maintain efficiency.
Implementation Method 1
a first vibration damping process of generating, in the first rotary electric machine, a vibration damping torque for suppressing vehicle body vibration
Implementation Method 2
a second vibration damping process of generating, in the second rotary electric machine, the vibration damping torque for suppressing the vehicle body vibration
Data Source
AI summary
During the execution of the combustion stopping process for continuing the combustion of the remaining cylinders while the combustion of some of the plurality of cylinders provided in the engine is stopped, the first vibration damping process for generating the vibration damping torque in the first rotary electric machine M1 and the second vibration damping process for generating the vibration damping torque in the second rotary electric machine M2 are executed.