Lockup Clutch Torque Detection via Dynamic Model
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Solution Overview
Problem
Existing torque converter systems lack an effective method to detect when a lockup clutch is transmitting a discernable amount of torque, which is crucial for optimal engagement and performance in automatic transmissions.
Innovation Solution
A method involving a dynamic model that uses monitored torque converter operating parameters, such as engine inertia, torque applied by the engine, rotational speeds of the pump and turbine, and angular acceleration, to determine the torque transmitted by the lockup clutch and produce a lockup clutch on-coming capacity signal if it exceeds a torque threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a lockup clutch is engaged in a torque converter, then torque transmission efficiency is improved, but the ability to detect when the clutch is transmitting discernable torque deteriorates due to lack of effective detection methods
Solution Approach 1:
The patent uses an intermediary dynamic model that relates lockup clutch torque to easily measurable torque converter parameters (pump torque, turbine torque, angular acceleration). This model acts as a mediator to indirectly detect clutch torque without requiring direct measurement sensors on the clutch itself, thus resolving the detection capability problem while maintaining energy efficiency benefits
Solution Approach 2:
The patent replaces the need for direct mechanical torque measurement on the lockup clutch with a computational approach using a dynamic model. Instead of using complex mechanical sensors or direct measurement systems on the clutch, the solution substitutes a mathematical model that computes clutch torque from other measurable parameters, achieving detection capability without additional mechanical complexity
2Measurement precision
If direct measurement of lockup clutch torque is implemented, then detection precision is improved, but device complexity increases due to additional sensors and measurement systems
Solution Approach 1:
The patent makes the existing torque converter dynamic model serve multiple functions: it continues to control torque converter operation while simultaneously providing lockup clutch torque detection capability. By making the model universal, the system achieves detection precision without adding separate dedicated measurement hardware, thus avoiding increased device complexity
Solution Approach 2:
The system uses its own existing operational parameters (pump torque, turbine torque, angular acceleration) to self-detect the lockup clutch torque state. The torque converter system essentially monitors itself using its existing sensor network and operational data, eliminating the need for external or additional detection hardware and maintaining simplicity
Data Source
AI summary
A dynamic model is stored in memory that defines torque transmitted by a lockup clutch in a torque converter as a function of a plurality of torque converter operating parameters. A lockup clutch command to control engagement the lockup clutch is asserted, and thereafter a number of the plurality of torque converter operating parameters are monitored. The model is continually solved using the monitored operating parameters to determine torque transmitted by the lockup clutch over time, and a lockup clutch on-coming capacity signal is produced if the torque transmitted by the lockup clutch exceeds a torque threshold.