Automatic Transmission Shift Control for Busy Shifting Prevention
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Solution Overview
Problem
Existing shift control apparatuses for automatic transmissions often cause busy shifting in manual shift mode due to integrated control functions intended for automatic shift mode, leading to unintended drive power source brake forces, which complicates driver intent and increases development costs.
Innovation Solution
A shift control apparatus that includes shift manner changing means and change limiting means, allowing the shift manner to be prohibited from changing when the vehicle speed is below a reference vehicle speed in manual shift mode, thereby separating and limiting the drive power source brake controlling function while maintaining the busy-shifting preventing function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shift manner changing means performs integrated control functions in manual shift mode to prevent busy shifting, then busy shifting is prevented, but unintended drive power source brake forces occur and driver intent is compromised
Solution Approach 1:
The control functions are segmented into two distinct modes: automatic shift mode (D range) where shift manner changing means operates fully to prevent busy shifting, and manual shift mode (S range) where change limiting means restricts shift manner changes to preserve driver intent. This segmentation allows the system to provide busy shifting prevention when automatically controlled while avoiding unintended brake forces when manually controlled.
Solution Approach 2:
The system dynamically switches between full shift manner changing capability and restricted shift manner changing based on the selected shift mode. When the driver selects manual shift mode, the change limiting means activates to prohibit shift manner changes that would generate unintended drive power source brake forces, while allowing the driver's manual shift commands to take precedence.
2Ease of operation
If the shift manner changing means is restricted in manual shift mode to preserve driver intent, then driver control is maintained, but busy shifting prevention function is lost
Solution Approach 1:
The control system is divided into two operational segments: automatic shift mode where shift manner changing means fully operates to prevent busy shifting through AI-based control, and manual shift mode where change limiting means restricts shift manner changes to preserve driver intent. This segmentation ensures each mode receives the appropriate level of automated intervention.
Solution Approach 2:
The shift control apparatus provides universal functionality across both automatic and manual shift modes by integrating shift manner changing means and change limiting means in the same control unit. This allows the system to adapt its behavior based on the selected mode while using a unified control architecture, avoiding the need for separate control systems.
3Reliability
If a new control program is developed exclusively for manual shift mode to prevent busy shifting, then busy shifting is prevented, but development time and cost increase tremendously
Solution Approach 1:
The patent merges the shift manner changing means (AI-based busy shifting prevention) and change limiting means (driver intent preservation) into a single integrated control program that operates based on the selected shift mode. This unified approach eliminates the need for separate control programs for automatic and manual modes, significantly reducing development time and cost while maintaining both busy shifting prevention and driver control authority.
Solution Approach 2:
A single control program provides universal functionality for both automatic and manual shift modes by incorporating conditional logic that activates shift manner changing in automatic mode and change limiting in manual mode. This multi-functional approach allows one program to serve multiple purposes across different operating conditions.
Data Source
AI summary
When an n speed prohibition command is being output from the AI shift controlling component, the AI shift control is performed even in the S mode if the vehicle speed V is lower than the reference vehicle speed Vn, whereby busy shifting can be effectively prevented when the vehicle is running on an uphill road or cornering. When the vehicle speed V is equal to or higher than the reference vehicle speed Vn, the AI shift control is cancelled, thus minimizing the possibility of a large engine brake force being applied to the vehicle despite the intention of the driver.