Electric Vehicle Motor Vibration Control via Virtual Pedal Position
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Solution Overview
Problem
Electric vehicles experience vibration issues due to the lack of damping elements between the motor and driving shaft, leading to reduced ride comfort and power performance when attempting to maximize motor torque, as existing vibration reduction logic compromises output torque.
Innovation Solution
A system and method that utilizes an accelerator pedal position sensor and controller to calculate a virtual position value of the accelerator pedal, applying a vibration reduction torque gain based on this value to optimize motor torque output while minimizing vibration, using filters to adjust the gain accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If vibration reduction logic is applied by multiplying deviation by predetermined value, then vibration is reduced, but output torque is reduced below maximum torque
Solution Approach 1:
The patent dynamically adjusts the vibration reduction torque gain based on accelerator pedal position and its rate of change, rather than using a fixed predetermined value. This allows the system to adapt the vibration reduction strength according to driving conditions, maintaining maximum torque when needed while reducing vibration during normal operation.
Solution Approach 2:
The patent changes the parameter of vibration reduction torque gain from a fixed predetermined value to a variable value determined by accelerator pedal position and acceleration demand. This parameter change enables the system to optimize both vibration reduction and torque output based on real-time driving conditions.
2Device complexity
If damping element is omitted between motor and driving shaft, then device complexity is reduced, but vibration and shock increase
Solution Approach 1:
The patent replaces the mechanical damping element with a control system that calculates and applies vibration reduction torque electronically. This substitution eliminates the need for physical damping components while achieving vibration reduction through software-based torque adjustment.
Solution Approach 2:
The patent introduces a controller as an intermediary between the motor and driving shaft, which processes accelerator pedal position information and applies vibration reduction torque to mitigate vibration without requiring a physical damping element in the mechanical path.
3Power
If maximum torque is requested during tip-in/out operation, then power performance is improved, but vibration and shock increase
Solution Approach 1:
The patent applies preliminary anti-action by detecting rapid accelerator pedal movement (tip-in/out conditions) and preemptively adjusting the vibration reduction torque gain to counteract the resulting shock and vibration before they fully manifest, allowing maximum torque delivery while mitigating harmful effects.
Data Source
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AI summary
A system and a method of controlling a motor for reducing vibration of an electric vehicle are provided that maximize an output torque of the motor by applying a vibration reduction torque gain based on a position value of the accelerator pedal. The system includes a driving motor as a power source and an accelerator pedal position sensor configured to detect a position value of an accelerator pedal. In addition, a controller is configured to calculate a virtual position value of the accelerator pedal limited to an increasing slope or a descending slope based on the position value of the accelerator pedal, and output a final torque of the driving motor by applying a vibration reduction torque gain based on the virtual position value of the accelerator pedal.