Vehicle Clutch Control Using Offset Engine Torque Compensation
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Solution Overview
Problem
Inaccurate engine torque estimation in vehicles with dry clutches leads to excessive slip or impact during clutch control, as existing methods fail to accurately account for factors like drag torque and air conditioner load, resulting in unstable shift control and potential engine flare.
Innovation Solution
A method that determines the offset engine torque by considering engine torque, angular acceleration, rotary inertia, and clutch torques, and uses this offset torque to control the clutch, ensuring accurate transmission input torque, particularly during engine idle states and gear shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional engine torque estimation methods are used, then the control system is simple, but the engine torque accuracy deteriorates due to unaccounted drag torque and air conditioner load
Solution Approach 1:
The patent implements feedback by measuring actual engine speed, calculating engine angular acceleration, and using this information to compute offset engine torque that compensates for drag torque and air conditioner load. The controller continuously monitors engine state and adjusts torque estimation based on real-time measurements, improving accuracy without requiring additional complex hardware.
Solution Approach 2:
The system uses the engine's own operational parameters (engine speed, angular acceleration, rotary inertia) to self-determine the offset torque. By leveraging readily available sensor data and physical properties already present in the system, the method achieves accurate torque estimation without external intervention or complex additional components.
2Reliability
If inaccurate engine torque information is used, then the control algorithm is simple, but clutch control stability deteriorates leading to excessive slip or impact
Solution Approach 1:
The patent performs preliminary calculation of offset engine torque during engine idle state before actual clutch engagement. By pre-determining the accurate torque value and storing it, the system ensures reliable torque information is available when clutch control is needed, preventing excessive slip or impact without requiring complex real-time adjustments during critical operations.
Solution Approach 2:
The system changes the torque parameter from conventional estimated values to offset engine torque that incorporates compensation for drag torque and air conditioner load. This parameter transformation, based on engine angular acceleration and rotary inertia measurements, fundamentally improves clutch control stability by providing accurate torque information.
3Measurement precision
If offset engine torque calculation is performed continuously, then torque accuracy is maintained, but computational load and processing time increase
Solution Approach 1:
The patent calculates offset engine torque in advance during engine idle state and stores the determined value. This preliminary calculation approach ensures accurate torque information is ready for use during clutch engagement without requiring continuous real-time computation, reducing processing time while maintaining accuracy.
Solution Approach 2:
The system performs offset torque calculation periodically during specific engine states (idle state with sustained torque rise) rather than continuously. By triggering calculations only when conditions are favorable and storing results for later use, the method balances accuracy requirements with computational efficiency.
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 clutch control precision and stability by compensating for inaccurate engine torque, ensuring reliable starting and shifting, and learning accurate clutch transmission torque characteristics, thereby enhancing drivability and shift quality.
Implementation Method 1
the offset engine torque may be determined by a function representing relations with engine torque, engine angular acceleration, engine rotary inertia and clutch torques
Data Source
AI summary
A method of controlling a clutch for vehicle may include determining, by a controller, raised offset engine torque, when engine torque is raised to a reference torque or more in an engine idle state, and controlling, by the controller, the clutch based on the determined offset engine torque.