Transmission Control Unit Gear Shifting Dynamics
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Solution Overview
Problem
When switching from a driving mode other than sports mode to sports mode during traveling, existing automatic transmission systems perform gear shifting uniformly based on the sports mode-dedicated gear-shifting pattern, failing to satisfy the driver's desire for dynamic driving and increased responsiveness.
Innovation Solution
A method and system that dynamically adjust gear shifting by setting a target gear-shifting step to a low-level step lower than the sports mode-dedicated gear-shifting pattern, determining the maximum number of allowable low-level gear-shifting steps based on acceleration pedal operation, computing the expected speed of the turbine, and executing gear-shifting control to ensure the speed does not exceed the allowable speed, thereby allowing down-shifting to a lower gear step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If gear shifting is performed uniformly based on the sports mode-dedicated gear-shifting pattern when switching to sports mode during traveling, then the gear-shifting control is simplified, but the driver's desire for dynamic driving and increased responsiveness is not satisfied
Solution Approach 1:
The patent applies dynamics by making the gear-shifting control adaptive rather than static. When a mode switch to sports mode is detected during traveling, the system dynamically adjusts the gear-shifting pattern to force down-shifting to lower gear steps, creating a more responsive driving experience that adapts to the driver's intent rather than following a fixed pattern
Solution Approach 2:
The patent changes the gear-shifting parameters (target gear step, shifting timing) based on the detected mode switch event. By modifying the gear-shifting map parameters to allow down-shifting to lower steps than normally permitted, the system transforms the gear-shifting behavior to match the sports mode intent, resolving the contradiction between simplified control and driver responsiveness
2Speed
If down-shifting to a lower gear step is enabled when switching to sports mode, then vehicle responsiveness is enhanced, but the complexity of gear-shifting control increases
Solution Approach 1:
The patent applies preliminary action by detecting the mode switch event before executing gear-shifting operations. The system prepares the gear-shifting control in advance by switching to a sports mode-specific gear-shifting pattern that permits down-shifting to lower steps, ensuring that when the driver needs responsive acceleration, the transmission is already configured to deliver it without complex real-time calculations
3Adaptability or versatility
If the target gear-shifting step is set to a low-level step lower than the sports mode-dedicated pattern, then dynamic driving experience is improved, but the risk of exceeding allowable turbine speed increases
Solution Approach 1:
The patent applies feedback by continuously monitoring the turbine speed and using this information to constrain the gear-shifting decisions. The control unit calculates the expected turbine speed after each potential down-shifting operation and compares it against the allowable speed threshold, adjusting the target gear step selection to ensure reliability while still enabling dynamic driving experience through down-shifting
Data Source
AI summary
In one aspect, a method of controlling gear shifting in response to a driving mode change, the method including determining a maximum number of allowable low-level gear-shifting steps according to a result of determining a state of a transmission, computing an immediate post-gear-shifting expected speed of a turbine for each step included that is within the maximum number of allowable low-level gear-shifting steps, using a current speed of an output shaft of the transmission and a gear ratio of each step and comparing the computed expected speed of the turbine with a preset allowable speed thereof for each step, setting the lowest-level gear-shifting step, among gear-shifting steps at which the expected speed of the turbine and the allowable speed thereof satisfy a predetermined condition, is set to be a target gear-shifting step, and executing gear-shifting control for shifting a current gear-shifting step down to the target gear-shifting step.