Clutch Control Method Using Current-Hydraulic Pressure Model for VKP Learning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic multiple disc clutch control methods face challenges in accurately and quickly learning the Volumetric Kiss Point (VKP), which affects the linearity of hydraulic pressure control and subsequently the efficiency of power transmission.
Innovation Solution
A clutch control method that generates a current-hydraulic pressure model, calculates differences between virtual and measured hydraulic pressures, and learns the VKP by identifying the maximum difference point to improve clutch control accuracy and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional clutch control methods are used, then the system structure remains simple, but the VKP learning speed and accuracy are insufficient
Solution Approach 1:
The patent applies preliminary action by pre-generating a current-hydraulic pressure model through offline experiments before actual clutch operation. The model captures the relationship between solenoid valve current and hydraulic pressure, including the nonlinear VKP region. During operation, the controller uses this pre-established model to rapidly identify VKP by comparing model predictions with actual sensor readings, eliminating the need for complex real-time modeling and achieving fast, accurate VKP learning without increasing hardware complexity
Solution Approach 2:
The patent implements feedback by continuously monitoring the difference between hydraulic pressure values predicted by the current-hydraulic pressure model and those actually measured by sensors during clutch operation. The controller adjusts the solenoid valve current based on this feedback, identifying the VKP point when the difference reaches a maximum. This closed-loop feedback mechanism enables accurate and rapid VKP detection while maintaining a relatively simple control system structure
2Speed
If traditional clutch control methods are used, then the control system remains simple, but the clutch control quickness is insufficient
Solution Approach 1:
The patent applies preliminary action by pre-generating a current-hydraulic pressure model through offline experiments before actual clutch operation. The model captures the relationship between solenoid valve current and hydraulic pressure, including the nonlinear VKP region. During operation, the controller uses this pre-established model to rapidly identify VKP by comparing model predictions with actual sensor readings, eliminating the need for complex real-time modeling and achieving fast, accurate VKP learning without increasing hardware complexity
Solution Approach 2:
The patent replaces traditional mechanical trial-and-error VKP detection methods with an electronic modeling approach. Instead of using complex mechanical sensors and actuators to physically probe the VKP point, the system uses a computational current-hydraulic pressure model combined with electronic feedback control to mathematically identify the VKP. This substitution of mechanical detection with electronic-computational methods achieves faster response and reduced system complexity
3Force
If hydraulic pressure is increased to improve clutch engagement, then engagement force improves, but hydraulic pressure linearity deteriorates due to VKP region
Solution Approach 1:
The patent applies preliminary action by pre-generating a current-hydraulic pressure model through offline experiments before actual clutch operation. The model captures the relationship between solenoid valve current and hydraulic pressure, including the nonlinear VKP region. During operation, the controller uses this pre-established model to rapidly identify VKP by comparing model predictions with actual sensor readings, eliminating the need for complex real-time modeling and achieving fast, accurate VKP learning without increasing hardware complexity
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the solenoid valve current based on the identified VKP point and the current clutch engagement stage. When approaching the VKP region, the controller modifies the current increase rate to account for the nonlinear hydraulic response, ensuring smooth pressure buildup. This dynamic parameter adjustment maintains hydraulic pressure control linearity while achieving sufficient clutch engagement force, resolving the contradiction between force and linearity
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 enables rapid and accurate VKP learning, enhancing clutch control quickness and accuracy, leading to improved shifting performance and commercial vehicle value by preventing excessive hydraulic pressure and ensuring precise clutch engagement and torque control.
Implementation Method 1
a solenoid valve 510 which is controlled by a controller 508 can supply desired hydraulic pressure to the pistons 504
Implementation Method 2
a piston 504 which is operated by hydraulic pressure implements an engaged state that transmits power by pressing the overlapping clutch plates 500 and clutch discs 502
Implementation Method 3
the piston 504 is returned to the initial position by elasticity of a spring 506
Implementation Method 4
transmits power by pressing the overlapping clutch plates 500 and clutch discs 502 in close contact with each other
Data Source
AI summary
A clutch control method may include generating a current-hydraulic pressure model by obtaining an increasing slope of a measured hydraulic pressure which is applied to a clutch in accordance with an increase of a primary ramp current while applying the primary ramp current to a solenoid valve that controls hydraulic pressure to be supplied to the clutch; obtaining a difference between a virtual hydraulic pressure according to the current-hydraulic pressure model and a measured hydraulic pressure applied to the clutch for a secondary ramp current while applying the secondary ramp current to the solenoid valve after removing the primary ramp current; performing updating by learning a secondary ramp current, at which the difference between the virtual hydraulic pressure and the measured hydraulic pressure is maximum, as a Volumetric Kiss Point (VKP); and controlling the clutch on the basis of the learned VKP.