Automatic Transmission Controller Torque Phase Timing
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Solution Overview
Problem
Existing automatic transmission systems face challenges in performing gear shifts via intermediate stages with input switching, leading to increased clutch heat and gear shift shocks, and lack effective methods to enhance driving force during such shifts.
Innovation Solution
A controller for automatic transmissions that employs torque phase control, specifically adjusting the torque phase control execution time to be shorter during input switching events, allowing for precise engagement of frictional engagement elements and rapid gear shifts through intermediate stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a gear shift is performed via an intermediate shift stage with input switching, then the clutch heat quantity is decreased, but the gear shift execution time increases and driving force is reduced
Solution Approach 1:
The control method dynamically adjusts the torque phase control execution time based on whether input switching occurs during the gear shift. When input switching is detected, the execution time is set to a shorter duration compared to gear shifts without input switching. This dynamic adjustment optimizes the balance between heat reduction and shift speed by adapting the control parameters to the specific shift conditions.
Solution Approach 2:
The invention changes the torque phase control execution time parameter according to the presence of input switching. By setting different execution time values for different shift scenarios (with or without input switching), the system optimizes both clutch heat reduction and gear shift speed. This parameter adjustment allows the system to maintain high driving force while still achieving heat reduction benefits through intermediate stage shifts.
2Productivity
If torque phase control execution time is shortened during input switching, then driving force is increased and gear shift speed is improved, but control precision requirements increase
Solution Approach 1:
The control method incorporates feedback by detecting whether input switching occurs during the gear shift process. Based on this detection, the system automatically adjusts the torque phase control execution time. This feedback mechanism ensures that the shortened execution time is only applied when appropriate (during input switching), maintaining control precision while achieving faster gear shifts and improved driving force.
3Loss of time
If a jump gear shift is performed directly without intermediate stage, then the gear shift execution time is reduced, but the clutch heat quantity increases
Solution Approach 1:
The system dynamically selects the gear shift path (direct jump shift or shift via intermediate stage) and adjusts the torque phase control execution time based on real-time conditions. When performing jumps over two or more stages, the system can choose to pass through an intermediate stage with dynamically adjusted execution time, balancing heat reduction needs with time efficiency.
Solution Approach 2:
The invention changes the torque phase control execution time parameter to optimize the balance between direct jump shifts and intermediate stage shifts. By adjusting this parameter, the system can achieve faster execution when using intermediate stages, making the heat reduction benefit more acceptable while still maintaining overall gear shift efficiency.
Data Source
AI summary
When a jump downshift via an intermediate shift stage is requested and a rotation speed of an input shaft approaches a synchronous rotation speed of the intermediate shift stage, a target torque phase time when the gear shift via the intermediate shift stage is performed with input switching is set to be shorter than that when the gear shift via the intermediate shift stage is performed without using input switching and torque phase control is performed. Accordingly, it is possible to promptly perform engagement of an engagement-side frictional engagement element at the time of passing through the intermediate shift stage and to rapidly perform the gear shift after passing through the intermediate shift stage.