EV Torque Gradient Control for Wheel Speed Vibration Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle torque control methods cause persistent vehicle vibration due to fluctuations in wheel speed when actual output torque approaches or exceeds the limited torque value, leading to compromised driving smoothness.
Innovation Solution
A vehicle torque control method that adjusts actual output torque based on a torque adjustment gradient value, determined by calculating differences between actual and limited torque values, and applying differentiated gradient limits for torque increases and decreases to suppress wheel speed fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single torque filtering coefficient is applied to reduce the demanded driving torque when the actual output torque approaches or exceeds the limited torque value, then the torque is reduced to meet the limit, but the wheel speed fluctuates and causes persistent vehicle vibration
Solution Approach 1:
The patent applies dynamic gradient adjustment by determining different torque adjustment gradient values based on the sign of the difference between actual and limited torque. When actual torque exceeds limited torque, a negative gradient is applied; when it's below, a positive gradient is applied. This dynamic adjustment stabilizes wheel speed and eliminates persistent vehicle vibration while maintaining torque limit compliance.
Solution Approach 2:
The patent changes the parameter of torque adjustment gradient from a single fixed value to multiple values based on the torque difference sign. By searching for gradient values corresponding to different difference ranges in a preset gradient value list, the system adapts the torque adjustment strategy to the current operating condition, resolving the contradiction between torque limiting and vibration suppression.
2Reliability
If the demanded driving torque is reduced to meet the limited torque value, then the torque limit is satisfied, but the wheel speed fluctuates downward or upward causing persistent vibration
Solution Approach 1:
The patent implements feedback control by calculating the difference between actual and limited torque, determining the sign of this difference, and using it to select appropriate torque adjustment gradient values. This feedback mechanism continuously adjusts the torque to maintain wheel speed stability and prevent persistent vibration while satisfying torque limits.
Solution Approach 2:
The system dynamically adjusts the torque gradient based on real-time torque difference sign, switching between positive and negative gradient values to stabilize wheel speed fluctuations. This dynamic response prevents the persistent vibration caused by static torque filtering approaches.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A vehicle torque control method, comprising: during the driving process of an electric vehicle, acquiring the actual output torque value of the electric vehicle at a first moment; calculating the difference between the actual output torque value and a limit torque value of the electric vehicle; determining a torque adjustment gradient value on the basis of the difference; and adjusting the actual output torque value of the electric vehicle at the first moment on the basis of the torque adjustment gradient value to obtain a driving demand torque value of the electric vehicle at a second moment, wherein the second moment is later than the first moment and is adjacent to the first moment. The method can reduce the duration and frequency of continuous vibrations of electric vehicles, thereby improving the driving experience of electric vehicles. Also disclosed are an apparatus, a computer device, a vehicle, a computer readable storage medium, and a computer program product.