Vehicle Torque Phase Control for Shift Vibration
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Solution Overview
Problem
In stepped type automatic transmissions, torque phase control using target torque phase time can result in sudden changes in driving force or vibration due to torsion, or decreased drivability due to hesitation, and may also lead to reduced durability of friction materials during downshifts.
Innovation Solution
A control device and method that sets the target torque phase time based on the output shaft torque difference before and after a gear shift, with an option to set an upper limit on this time during downshifts to prevent excessive thermal load on friction materials, thereby balancing driving force consistency and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the target torque phase time is set to be short to enable rapid gear shift response, then the gear shift speed is improved, but sudden change in driving force or vibration due to torsion of output shaft occurs
Solution Approach 1:
The patent applies dynamics by making the target torque phase time variable rather than fixed. The control device dynamically adjusts the target torque phase time based on real-time operating conditions (accelerator position, gear shift type, torque phase start time) to optimize the balance between gear shift speed and driving force smoothness. This dynamic adjustment allows the system to achieve rapid gear shift response when conditions permit while preventing sudden driving force changes or vibrations when conditions require smoother transitions.
Solution Approach 2:
The patent applies parameter changes by modifying the target torque phase time parameter according to different operating conditions. Specifically, the control device changes this parameter based on accelerator position (larger position → shorter time for rapid response; smaller position → longer time for smooth transition), gear shift type (upshift vs. downshift), and torque phase start time. This parameter adjustment resolves the contradiction by adapting the torque phase time to match the desired gear shift characteristics under varying driving conditions.
2Object-affected harmful factors
If the target torque phase time is set to be long to achieve smooth gear shift, then drivability is improved, but drivability decreases due to hesitation of change in driving force
Solution Approach 1:
The patent applies dynamics by making the target torque phase time variable rather than fixed. The control device dynamically adjusts the target torque phase time based on real-time operating conditions (accelerator position, gear shift type, torque phase start time) to optimize the balance between gear shift speed and driving force smoothness. This dynamic adjustment allows the system to achieve rapid gear shift response when conditions permit while preventing sudden driving force changes or vibrations when conditions require smoother transitions.
Solution Approach 2:
The patent applies parameter changes by modifying the target torque phase time parameter according to different operating conditions. Specifically, the control device changes this parameter based on accelerator position (larger position → shorter time for rapid response; smaller position → longer time for smooth transition), gear shift type (upshift vs. downshift), and torque phase start time. This parameter adjustment resolves the contradiction by adapting the torque phase time to match the desired gear shift characteristics under varying driving conditions.
3Object-affected harmful factors
If the target torque phase time is set to be long during driving downshift to prevent sudden driving force change, then drivability is improved, but thermal load on friction material increases and durability decreases
Solution Approach 1:
The patent applies dynamics by making the target torque phase time variable rather than fixed. The control device dynamically adjusts the target torque phase time based on real-time operating conditions (accelerator position, gear shift type, torque phase start time) to optimize the balance between gear shift speed and driving force smoothness. This dynamic adjustment allows the system to achieve rapid gear shift response when conditions permit while preventing sudden driving force changes or vibrations when conditions require smoother transitions.
Solution Approach 2:
The patent applies parameter changes by modifying the target torque phase time parameter according to different operating conditions. Specifically, the control device changes this parameter based on accelerator position (larger position → shorter time for rapid response; smaller position → longer time for smooth transition), gear shift type (upshift vs. downshift), and torque phase start time. This parameter adjustment resolves the contradiction by adapting the torque phase time to match the desired gear shift characteristics under varying driving conditions.
Data Source
AI summary
An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.