E-4WD Hybrid Torque Distribution for Slip Control
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Solution Overview
Problem
E-4WD hybrid vehicles face challenges in fuel efficiency and wheel slip control, particularly in 4WD mode, where fuel efficiency deteriorates and steering stability is compromised due to decreased road surface friction on rainy, snowy, or frozen roads.
Innovation Solution
A method for controlling E-4WD hybrid vehicles that involves distributing drive torque between front and rear wheels based on weight movement ratios and engine operating points, using a controller to adjust torque distribution ratios and prevent wheel slip by redistributing torque from slipping wheels to maintain optimal driving conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vehicle is driven in 4WD mode to improve posture control and steering ability, then climbing performance and escape capability are improved, but fuel efficiency deteriorates
Solution Approach 1:
The system dynamically switches between 2WD and 4WD modes based on real-time driving conditions and torque requirements. The drive torque distribution control unit adjusts the torque distribution ratio between front and rear wheels dynamically, allowing the vehicle to operate in 2WD mode for fuel efficiency when conditions permit, and switch to 4WD mode when traction or posture control is needed, thus resolving the contradiction between reliability and energy consumption
Solution Approach 2:
The system changes the operational parameters by adjusting the drive torque distribution ratio between front and rear wheels. By controlling the torque distribution ratio based on weight moving ratio and driving conditions, the system optimizes the balance between traction performance (reliability) and energy consumption, allowing flexible parameter adjustment to resolve the contradiction
2Use of energy by moving object
If the vehicle is driven in 2WD mode to improve fuel efficiency, then fuel consumption is reduced, but steering stability deteriorates on low-friction roads
Solution Approach 1:
The system dynamically adjusts the drive mode based on real-time conditions. When driving on low-friction roads (rainy, snowy, or frozen roads), the system can switch from 2WD to 4WD mode to improve steering stability and posture control, while maintaining fuel efficiency by operating in 2WD mode under normal conditions. This dynamic adaptation resolves the contradiction between fuel efficiency and steering stability
3Power
If drive torque is increased to improve acceleration performance, then start performance is improved, but wheel slip increases on slippery surfaces
Solution Approach 1:
The system applies different torque distribution strategies to different wheel pairs based on local conditions. The drive torque distribution control unit adjusts the torque distribution ratio between front and rear wheels independently, allowing torque to be distributed to wheels with better traction. This localized torque management improves acceleration performance while preventing wheel slip on slippery surfaces
Solution Approach 2:
The system uses feedback from wheel slip detection and driving conditions to adjust torque distribution in real-time. When wheel slip is detected, the control unit modifies the torque distribution ratio to reduce slip, thereby maintaining acceleration performance while improving wheel slip control through continuous feedback adjustment
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 improves start performance and acceleration by reducing wheel slip, increases energy recovery through regenerative braking, and enhances fuel efficiency by optimizing engine operation based on battery charging operations.
Implementation Method 1
a motor to generate driving force
Implementation Method 2
a starter-generator that starts the engine or generates electricity by output of the engine
Data Source
AI summary
A method for controlling an electric four wheel drive hybrid vehicle includes steps of: receiving, by a controller, a longitudinal acceleration of the hybrid vehicle corresponding to a demand torque of a driver of the hybrid vehicle; and determining, by the controller, a torque distribution ratio between a front wheel drive torque and a rear wheel drive torque of the hybrid vehicle based on a weight moving ratio of the hybrid vehicle corresponding to the received longitudinal acceleration.