Vehicle Clutch Torque Refill Control for Oil Temperature Stability
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Solution Overview
Problem
The variation in clutch torque transfer characteristics due to temperature changes in hydraulic actuators used for clutch control in vehicles leads to inaccurate and unstable clutch operation, affecting vehicle performance.
Innovation Solution
A clutch control method that involves increasing clutch torque to a refill execution torque during a micro-slip state, refilling the pressure chamber with oil from a reservoir tank, and maintaining the clutch torque at a refill torque to reduce temperature variations and stabilize clutch characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure is continuously applied to oil in a hydraulic actuator, then the actuator can maintain clutch engagement, but the oil temperature increases causing variation in torque transfer characteristics
Solution Approach 1:
The patent implements periodic refilling of the pressure chamber with fresh oil from the reservoir tank. The controller periodically opens the communication passage between the pressure chamber and reservoir tank to replace heated oil with cooler fresh oil, thereby cyclically resetting the oil temperature and maintaining consistent hydraulic pressure and clutch torque characteristics over time.
2Measurement precision
If the clutch torque is frequently adjusted to maintain accurate control, then clutch performance is improved, but the complexity of control increases
Solution Approach 1:
The system uses the clutch's own operational states (slip state detection) to trigger self-correction actions. When the controller detects that the clutch is in a slip state, it automatically initiates the refilling process without external intervention, allowing the system to self-regulate and maintain accuracy through its own operational feedback.
Solution Approach 2:
The controller continuously monitors clutch operational parameters including slip state and torque transfer characteristics. Based on this feedback, the controller dynamically adjusts the refilling timing and duration, creating a closed-loop control system that maintains accurate clutch torque control while adapting to changing operating conditions.
3Loss of information
If the clutch operates in a micro-slip state for extended periods, then learning of clutch characteristics is enabled, but temperature variations accumulate affecting control accuracy
Solution Approach 1:
The controller proactively initiates refilling operations based on predetermined conditions (such as elapsed time since last refilling or detection of slip state) before temperature variations significantly degrade control accuracy. This preliminary action prevents the accumulation of temperature effects that would otherwise compromise both learning accuracy and control precision.
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 method reduces temperature-related variations in clutch characteristics, enabling more accurate and stable clutch control, improving vehicle performance by maintaining consistent clutch operation.
Implementation Method 1
a hydraulic actuator is used. In the case in which pressure is continuously applied to oil that generates hydraulic pressure
Implementation Method 2
when the clutch torque reaches the refill execution torque, increasing the clutch torque to a refill torque
Data Source
AI summary
A clutch control method for a vehicle includes: increasing, by a controller, a clutch torque to a refill execution torque at a predetermined first inclination when a predetermined first reference time period has elapsed in a micro-slip state of a clutch; increasing, by the controller, the clutch torque to a refill torque at a predetermined second inclination to initiate refilling of a pressure chamber of a hydraulic-driving actuator with oil in a reservoir tank when the clutch torque reaches the refill execution torque; and maintaining the clutch torque at the refill torque during a predetermined second reference time period.