AWD Drive Force Control for Rough Road Stuck Avoidance
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Solution Overview
Problem
Existing vehicles with all-wheel drive systems struggle to avoid getting stuck in rough road conditions, such as puddles, mud, or snow, as excessive drive force to the front wheels can lead to spinning and deeper entrapment.
Innovation Solution
A driving control apparatus equipped with a surrounding environment recognition device, brake control, and drive force control system that includes a rough road area determiner and road surface friction coefficient estimator, enabling first and second avoidance controls to prevent vehicle entrapment by adjusting brake and drive force distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If excessive drive force is applied to the front wheels to improve traction in rough road conditions, then the vehicle can overcome mud and puddles, but the front wheels may spin out and the vehicle may be caught into an even deeper level
Solution Approach 1:
The system dynamically adjusts the drive force distribution between front and rear wheels based on real-time detection of wheel spin conditions and road surface friction coefficients. When wheel spin is detected or low friction is estimated, the control unit reduces drive force to the spinning wheels and redirects it to non-spinning wheels, creating a dynamic balance that prevents harmful wheel spin while maintaining adequate traction.
Solution Approach 2:
The control unit changes the parameter of drive force magnitude based on detected conditions. By monitoring wheel rotation speeds and estimating road surface friction coefficients, the system adjusts the drive force parameter in real-time, reducing it when wheel spin occurs and increasing it when adequate grip is available, thereby resolving the contradiction between needing sufficient force for traction and avoiding excessive force that causes wheel spin.
2Adaptability or versatility
If the vehicle uses an all-wheel drive system to improve rough road performance, then the vehicle can drive in unpaved roads and unleveled land, but the vehicle may still be caught in water or stuck in mud
Solution Approach 1:
The system implements a feedback control mechanism where the control unit continuously monitors wheel rotation speeds, detects wheel spin conditions, and estimates road surface friction coefficients. Based on this feedback, the control unit adjusts drive force distribution in real-time, redirecting power from spinning wheels to non-spinning wheels, thereby reliably preventing the vehicle from getting stuck in rough road conditions.
Solution Approach 2:
The system performs preliminary detection of wheel spin conditions and road surface friction coefficients before the vehicle becomes fully stuck. By anticipating problematic conditions through continuous monitoring and estimating friction coefficients, the control unit can proactively adjust drive force distribution to prevent wheel spin and avoid getting stuck, rather than reacting after the vehicle is already trapped.
3Object-generated harmful factors
If the control system detects wheel spin and reduces drive force, then wheel spin is prevented, but the vehicle may lose momentum and struggle to escape the stuck state
Solution Approach 1:
The control unit dynamically changes the drive force parameter based on real-time detection. When wheel spin is detected, the system reduces drive force to the spinning wheels to prevent further spin. When wheel spin stops or non-spinning wheels are identified, the system increases drive force to those wheels to maintain or build momentum. This dynamic parameter adjustment prevents wheel spin while preserving the force needed to escape stuck conditions.
Solution Approach 2:
The system creates a dynamic drive force distribution that adapts to changing wheel conditions. Rather than maintaining a static low drive force setting, the control unit continuously adjusts drive force levels based on which wheels are spinning and which are providing traction, ensuring that sufficient force is always applied to effective wheels to maintain momentum while preventing force from being wasted on spinning wheels.
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
Effectively prevents vehicles from being caught in water or stuck in rough terrain by dynamically adjusting brake and drive force distribution based on environmental recognition, ensuring safe navigation.
Implementation Method 1
a road surface μ estimator configured to estimate a friction coefficient of a wheel contact surface of the vehicle
Data Source
AI summary
A driving control apparatus for a vehicle includes a surrounding environment recognition device, a brake control device, a drive force control device, and a control unit. The surrounding environment recognition device obtains surrounding environment information of the vehicle. The brake control device performs brake control for the vehicle. The drive force control device performs drive control of front wheels and rear wheels individually. The control unit at least includes a rough road area entry determiner which executes a determination of entry of the vehicle into a rough road area and a road surface μ estimator which estimates a friction coefficient of a wheel contact surface. The control unit executes first avoidance control and then second avoidance control when the vehicle is found to enter an area where it is likely to be stuck in the rough road area based on a determination result of the rough road area entry determiner.