Four-Wheel Drive Clutch Torque Control Using Friction Plate Temperature
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Solution Overview
Problem
Conventional methods for monitoring friction plate temperature in four-wheel drive systems suffer from lag and poor reliability, leading to inaccurate torque control and increased risk of friction plate ablation.
Innovation Solution
A method and system that directly calculate friction plate temperature using front and rear wheel speeds and output torque, correcting the calculated torque based on the friction plate temperature to achieve accurate output torque control, with additional features for overheat protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction plate temperature is monitored by measuring oil temperature, then temperature monitoring is implemented, but monitoring lag and poor reliability occur
Solution Approach 1:
The patent replaces the indirect mechanical measurement method (oil temperature sensor) with a direct calculation method based on thermal field theory. The friction plate temperature is calculated by integrating friction heat generation and heat dissipation over time, substituting physical sensor measurement with computational modeling to eliminate monitoring lag and improve reliability.
Solution Approach 2:
The patent introduces oil temperature as an intermediary parameter in the calculation model. While oil temperature is still measured, it serves as input data for the thermal field calculation rather than being the direct measurement target, enabling more accurate friction plate temperature determination through the heat transfer model.
2Measurement precision
If output torque is not corrected based on friction plate temperature, then control system is simple, but torque control accuracy deteriorates
Solution Approach 1:
The patent implements feedback control by continuously monitoring friction plate temperature and adjusting output torque accordingly. The calculated temperature feeds back to the control system, which modifies the torque output to prevent overheating and maintain optimal operating conditions, improving torque control accuracy through closed-loop regulation.
Solution Approach 2:
The patent dynamically changes the output torque parameter based on the calculated friction plate temperature. When temperature exceeds thresholds, the system adjusts torque magnitude and distribution, transforming a static control parameter into a dynamic one that adapts to thermal conditions, thereby improving control accuracy.
3Strength
If friction plate temperature is not monitored accurately, then system operation is simple, but friction plate ablation and early failure occur
Solution Approach 1:
The patent performs preliminary thermal field calculation to predict friction plate temperature before actual thermal damage occurs. By continuously computing temperature based on friction heat generation and heat dissipation models, the system anticipates thermal conditions and takes preventive measures, protecting the friction plate from ablation and early failure.
Solution Approach 2:
The patent replaces direct physical temperature sensing of the friction plate with a computational thermal field model. This substitution eliminates the need for sensors in contact with the friction plate while providing accurate temperature prediction, thereby protecting the friction plate from thermal damage without requiring complex monitoring hardware.
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
Improves torque control accuracy, reduces friction plate ablation risk, and enhances vehicle maneuverability and trouble-getting-out ability by directly measuring friction plate temperature and adjusting torque accordingly.
Implementation Method 1
a friction plate heat generation is calculated
Implementation Method 2
a friction plate heat dissipation is calculated based on the historical temperature
Data Source
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AI summary
An intelligent four-wheel drive control method and system, and a vehicle. In the intelligent four-wheel drive control method, an output torque calculation value of a vehicle can be calculated by means of acquired vehicle condition information of the vehicle, the temperature of a friction plate of the vehicle is then calculated on the basis of a combination of a front wheel speed, a rear wheel speed and the output torque calculation value, and finally, the output torque calculation value is corrected according to the temperature of the friction plate, so as to obtain an actual output torque, and a friction clutch of the vehicle is controlled to output the actual output torque. In the intelligent four-wheel drive control method, the temperature of a friction plate is directly obtained according to real-time vehicle condition information, such that the precision is higher; in addition, an output torque calculation value is corrected according to the temperature of the friction plate, such that the control precision of an output torque is improved, thus improving the controllability and the escape capacity of a whole vehicle, and reducing the probability of the friction plate being burned and damaged.