ABS Wheel Motor Support for Faster Locked-Wheel Re-Acceleration
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Solution Overview
Problem
Conventional anti-lock braking systems (ABS) are limited in their ability to re-accelerate a locked wheel back to vehicle speed due to reliance on dynamic friction, which is inefficient, especially on low-friction surfaces, leading to prolonged braking distance and reduced braking force.
Innovation Solution
The method involves detecting a locked or nearly locked wheel and applying a targeted wheel drive force using a wheel drive motor to increase the wheel speed from dynamic friction to static friction, allowing for a higher braking force by exerting wheel drive force until the wheel reaches a specified threshold speed, potentially involving communication with the vehicle's drive system and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ABS relies on dynamic friction to re-accelerate a locked wheel, then the system structure remains simple, but the braking distance is prolonged and braking force is reduced
Solution Approach 1:
The patent replaces the conventional mechanical friction-based re-acceleration mechanism with an electric motor system. The wheel motor applies torque directly to the locked wheel through the drive shaft, substituting the passive dynamic friction mechanism with an active electromagnetic drive system, enabling faster and more controlled wheel speed recovery
Solution Approach 2:
The patent changes the fundamental parameter of friction type from dynamic friction to static friction by actively controlling the wheel speed through motor torque. By maintaining the wheel in a rotating state rather than allowing it to lock completely, the system operates in the static friction regime which provides higher braking force and faster response
2Speed
If a wheel drive motor is used to exert wheel drive force on the locked wheel, then the wheel speed increases faster, but the device complexity increases
Solution Approach 1:
The patent makes the wheel motor serve dual functions: it acts as both a drive motor for accelerating the wheel and as a braking mechanism through regenerative braking or torque reversal. This multi-functionality eliminates the need for separate braking actuators on each wheel, reducing overall system complexity despite the sophisticated control requirements
Solution Approach 2:
The wheel motor system uses the motor's own electromagnetic fields and control electronics to perform both acceleration and braking functions. The control unit directly manages the motor torque without requiring additional mechanical linkages or separate actuation systems, allowing the motor to service its own acceleration and braking needs
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 enables faster re-acceleration of the wheel to vehicle speed, reducing braking distance and enhancing braking force by transitioning the friction pairing from dynamic to static friction, thereby improving the effectiveness of the ABS system.
Implementation Method 1
re-acceleration of an overbraked wheel to the vehicle speed must take place merely via the dynamic friction between the wheel and the road... the friction pairing between this wheel and the roadway surface moves away from dynamic friction toward static friction
Data Source
AI summary
A method and device for supporting an anti-lock braking system in a motor vehicle. In the method, the presence of a locked or nearly locked wheel of the motor vehicle is ascertained, and if a locked wheel is present, a wheel drive force is exerted on this wheel in a targeted manner.