Transmission Garage Shift Control on Grades
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle transmission shift strategies fail to ensure smooth garage shifts when a vehicle is on a grade, leading to poor shift quality or prevention of shifting into desired gear due to rolling motion.
Innovation Solution
A method involving controllers that assess the vehicle's grade and rolling speed, using the electric park brake and transmission to stop the vehicle, engage a dog clutch, and manage clutch engagement to facilitate successful shifts into forward drive gears by temporarily holding the vehicle with the electric park brake until the dog clutch is engaged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transmission uses conventional shift strategies on grades, then the transmission structure remains simple, but the vehicle rolls on grades causing poor shift quality or prevention of shifting into desired gear
Solution Approach 1:
The system performs preliminary actions by detecting grade conditions and vehicle rolling state before the shift occurs, then preemptively engages the EPB to prevent rolling during the shift process. This advance preparation ensures the vehicle is stationary when the dog clutch engages, resolving the technical contradiction by maintaining simple transmission structure while achieving reliable shifts through proactive control.
2Reliability
If the vehicle uses EPB to hold the vehicle during garage shift on grades, then shift quality improves, but the shifting process time increases
Solution Approach 1:
The system uses periodic action by implementing a timed sequence where EPB is engaged for a specific duration during the shift process, then deactivated once the dog clutch engagement is confirmed. This controlled temporal pattern ensures shift quality while minimizing time loss, as the EPB is only active for the critical engagement period rather than continuously.
3Productivity
If the transmission engages dog clutch while vehicle is rolling, then the shifting process is faster, but the dog clutch may not engage properly causing shift failure
Solution Approach 1:
The system applies preliminary anti-action by detecting when the vehicle is rolling on a grade and preemptively engaging the EPB to counteract the rolling motion before the dog clutch engagement attempt. This prevents the harmful rolling effect from interfering with clutch engagement, ensuring reliable connection while maintaining efficient shift execution through coordinated brake and clutch control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves shift quality and ensures successful engagement of the transmission into desired gears by stabilizing the vehicle on grades, enhancing the overall shifting process.
Implementation Method 1
controlling, by the one or more controllers, an electric park brake (EPB) to hold the vehicle at the stop state
Data Source
Figure 1
Figure 2~4
Figure 3
AI summary
A method for interactive transmission garage shifts includes receiving a request for a transmission garage shift; controlling the transmission to bring the vehicle to a stop state based on determining that the vehicle is rolling backwards on a grade above a predetermined grade threshold and at a speed below a predetermined speed threshold; controlling an electric park brake (EPB) to hold the vehicle at the stop state; controlling the transmission to engage a dog clutch so as to place the transmission in a forward drive gear; and controlling the EPB to i) deactivate if the dog clutch is determined to be engaged, or ii) maintain activation to maintain the vehicle at the stop state if the dog clutch is determined to be disengaged.