Wheel-Individual Drive Torque Control on Split-Friction Roads
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Solution Overview
Problem
Existing motor vehicle systems require braking interventions to maintain driving stability, which wear down the brake system and are inefficient, especially on inhomogeneous road surfaces with varying coefficients of friction.
Innovation Solution
The method controls wheel-specific drive devices to adjust torque differences between drive wheels based on friction coefficients, ensuring stable static friction without braking interventions, by determining torque differences proportional to friction differences and adjusting them according to driving situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If braking interventions are applied to maintain driving stability on inhomogeneous road surfaces, then driving stability is ensured, but the brake system experiences wear and energy is lost
Solution Approach 1:
Instead of applying braking force to the wheel with higher friction coefficient (conventional approach), the invention applies drive torque to the wheel with lower friction coefficient. This inverted approach uses the drive system to compensate for friction differences, eliminating the need for braking interventions while maintaining driving stability and preventing brake wear
Solution Approach 2:
The invention replaces the mechanical braking system with an electromagnetic drive system for compensating friction coefficient differences. By using the wheel-specific drive devices to apply torque differences, the system eliminates the need for mechanical brake intervention, thereby reducing wear and energy loss
2Adaptability or versatility
If wheel-specific drive devices are used to individually torque drive wheels, then torque can be precisely controlled at each wheel, but the complexity of the drive system increases
Solution Approach 1:
The invention divides the drive system into wheel-specific independent drive units, where each drive wheel has its own drive device with independent torque control. This segmentation enables precise individual torque adjustment at each wheel based on local friction conditions, while the modular structure manages system complexity through distributed control
3Reliability
If braking torque is applied to compensate for friction coefficient differences, then static friction at drive wheels is maintained, but the brake system is subjected to wear during operation
Solution Approach 1:
The invention replaces the braking system with the drive system for maintaining static friction. By using wheel-specific drive devices to apply compensating torque differences, the system maintains static friction at all drive wheels without requiring brake intervention, thereby extending brake system service life while ensuring reliable traction
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 approach extends brake system lifespan, maintains driving stability, and enhances energy efficiency by eliminating the need for braking interventions, allowing comfortable driving on inhomogeneous surfaces while protecting the brake system from wear.
Implementation Method 1
controlling the drive devices of the wheel axle depending on a difference between longitudinal forces which can be applied to the road surface at the drive wheels of this wheel axle... both drive wheels of the same wheel axle apply drive torque and cornering forces to the road surface
Data Source
Figure 1~2
AI summary
The invention relates to a method for operating a motor vehicle (1), which has at least one wheel axle (2, 3) having two drive wheels (4-7), wherein each drive wheel (4-7) can be driven by a wheel-individual drive apparatus (8-11) in order to move the motor vehicle on a roadway. According to the invention, the drive apparatuses (8-11) of the wheel axle (2, 3) are controlled in accordance with a difference between the longitudinal forces that can be applied to the roadway at the drive wheels of the wheel axle (2, 3).