EV Gear-Meshing Torque Control for Low-Vibration Shifting
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Solution Overview
Problem
Gear-meshing in electric vehicles causes vibration due to non-zero torque transitions during gear changes, leading to significant torque and rotation speed fluctuations.
Innovation Solution
A control method and apparatus that reduce electric motor torque by controlling gear-meshing torque based on gear rotation distance, using pre-calibrated minimum and target torques to minimize vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor provides sufficient torque during gear-meshing to ensure gear engagement, then the gear-meshing action can be completed reliably, but the torque and rotation speed fluctuations cause significant vibration
Solution Approach 1:
The control method applies preliminary action by reducing the torque instruction before the gear-meshing action occurs. The VCU determines that the torque instruction should be reduced to a target value that is smaller than the minimum torque required for normal operation, preparing the system in advance to minimize vibration when gear-meshing occurs, while still ensuring reliable engagement through prior torque management.
2Object-affected harmful factors
If the torque instruction is reduced to minimize vibration during gear-meshing, then vibration is reduced, but the gear may not complete the meshing action reliably
Solution Approach 1:
The control method applies dynamics by dynamically adjusting the torque instruction based on the gear shift state. The VCU continuously monitors gear shift information and modifies the torque instruction in real-time - reducing it before and during gear-meshing to minimize vibration, then restoring it after meshing completes. This dynamic adjustment ensures both vibration reduction and reliable gear-meshing completion.
3Ease of operation
If the electric motor maintains normal torque during gear shift, then the gear can engage smoothly, but the non-zero torque transition causes rotation speed and torque impacts
Solution Approach 1:
The control method applies parameter changes by modifying the torque instruction parameter during gear shift. The VCU changes the torque instruction from the normal minimum torque value to a reduced target torque value specifically during the gear-meshing period. This parameter change reduces the torque impact and rotation speed impact while maintaining smooth gear engagement through controlled torque management.
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
Minimizes gear shift vibration by reducing electric motor torque and rotation speed during gear-meshing, ensuring smoother gear changes.
Implementation Method 1
the gear continues to rotate relying on inertia until the gear-meshing is completed
Data Source
Figure 1~2
AI summary
The present article discloses a control method and a control apparatus for suppressing gear shift vibration in the electric vehicle, and a device and a medium. The control method includes: acquiring a gear rotation distance when a gear-meshing action is started during gear shift of a vehicle; controlling the electric motor to execute the gear-meshing action in response to the gear rotation distance being smaller than the set distance, such that the gear-meshing action is started at the first time; controlling the electric motor to execute the gear-meshing action with a target gear-meshing torque until the gear-meshing action is completed in response to the gear rotation distance being greater than or equal to the set distance, and smaller than or equal to an actual gear clearance of the electric motor.