Torque Converter Clutch Slip Control via Dynamic Profile
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional torque converter clutch (TCC) control strategies in vehicle powertrains are time-consuming and costly, and lack transparency to vehicle occupants, affecting drivability during electronic clutch control (ECC) mode transitions.
Innovation Solution
A method for regulating TCC engagement by determining a slip profile based on vehicle operating parameters, calculating actual TCC slip, and adjusting TCC ramp pressure to achieve rapid and condition-specific slip regulation, enhancing drivability and eliminating the need for fixed calibration tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional control strategies with multiple look-up tables are used to regulate TCC engagement, then TCC slip can be controlled, but the control process becomes time-consuming and costly while reducing drivability and drive feel
Solution Approach 1:
The patent transforms the traditional approach of using multiple fixed look-up tables into a dynamic parameter-based control system. Instead of switching between discrete tables, the system continuously adjusts TCC ramp pressure based on real-time slip error and operating conditions, enabling adaptive control that is both rapid and precise without the computational overhead of multiple table lookups
Solution Approach 2:
The patent replaces the complex mechanical-like lookup table switching mechanism with a streamlined computational algorithm. The new approach uses direct mathematical relationships between slip error, ramp pressure, and TCC engagement, eliminating the need for multiple discrete control tables and their associated switching logic
2Reliability
If traditional control strategies with fixed look-up tables are used, then TCC engagement can be regulated, but the system lacks transparency to vehicle occupants, decreasing drivability
Solution Approach 1:
The patent implements a dynamic control approach where TCC ramp pressure is continuously adjusted based on real-time slip error and vehicle operating conditions. This dynamic adaptation allows the system to optimize engagement characteristics for different driving scenarios, improving drivability by making the transition smooth and context-appropriate rather than relying on fixed pre-programmed tables
Solution Approach 2:
The patent introduces a feedback mechanism that continuously monitors actual TCC slip and compares it to the target slip profile. The slip error signal is used to adjust ramp pressure in real-time, creating a closed-loop control system that adapts to actual vehicle conditions and provides transparent, natural-feeling engagement to occupants
3Device complexity
If a fixed TCC slip target is used, then control implementation is simplified, but slip regulation is slower and does not correspond to varying driving conditions
Solution Approach 1:
The patent replaces the static fixed slip target with a dynamic slip profile that adapts to varying vehicle operating conditions. The target slip is no longer a constant value but varies based on factors such as vehicle speed, engine torque, and transmission gear requests, enabling rapid and condition-specific slip regulation while maintaining relatively simple control implementation
Data Source
AI summary
A method and system for regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter includes determining a non-linear slip profile based on vehicle operating parameters, calculating an actual TCC slip, calculating a TCC ramp pressure based on the non-linear slip profile and the actual TCC slip and regulating a TCC engagement pressure based on the TCC ramp pressure.