Automatic Transmission Control Device for Shift Shock Reduction
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Solution Overview
Problem
Automatic transmissions experience excessive shift shock during jump-over gear shifts due to the increased number of engagements and releases of engaging devices, leading to a sluggish acceleration sensation for the driver.
Innovation Solution
A control device for automatic transmissions that uses an electronic control unit to select a setting pattern with a smaller number of engaging device switches during intermediate gear shifts, reducing shock and improving acceleration response by optimizing the engagement and release of clutch and brake mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the automatic transmission performs a jump-over gear shift through an intermediate gear shift stage, then the acceleration response is improved and sluggishness is suppressed, but the number of engagement and release operations of engaging devices increases, causing excessive shift shock
Solution Approach 1:
The patent segments the gear shift process by identifying multiple possible setting patterns for the intermediate gear shift stage, and further segments the selection criteria by evaluating each pattern based on the number of engaging device operations required. This allows the system to choose the optimal segment (setting pattern) that minimizes shock while maintaining acceleration response.
Solution Approach 2:
The control device performs preliminary analysis of multiple setting patterns before executing the gear shift. It calculates the number of engagement and release operations for each pattern in advance, and selects the optimal pattern before the actual shift occurs, thereby preventing excessive shift shock from the beginning.
2Adaptability or versatility
If multiple setting patterns are available for the intermediate gear shift stage, then the flexibility of control is improved, but the complexity of selecting the appropriate pattern increases
Solution Approach 1:
The patent changes the evaluation parameter for selecting setting patterns from arbitrary or performance-based criteria to a simple quantitative metric: the number of engaging device operations. This parameter change simplifies the selection process while maintaining control flexibility, as the ECU can efficiently compare numerical values to determine the optimal pattern.
Data Source
AI summary
A control device for an automatic transmission is provided. The automatic transmission is configured to realize a plurality of gear shift stages by combination of a plurality of engaging devices engaged or released among the plurality of engaging devices. The control device includes an electronic control unit. The electronic control unit is configured to select, as the setting pattern realizing an intermediate gear shift stage, the setting pattern with a smaller number of switching of the engagement or release of the engaging device than the number of switching of the setting pattern with the largest number of switching among the plurality of setting patterns when a shift is performed from a first gear shift stage to a second gear shift stage through the intermediate gear shift stage in a case where the electronic control unit determines that the shift is to be performed through the intermediate gear shift stage.