Vehicle Friction Control via Contactless Sensor Fusion
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Solution Overview
Problem
Existing vehicle control systems face challenges in accurately estimating road surface friction coefficients, leading to unstable vehicle behavior when transitioning from high to low friction surfaces, as they rely solely on contact-based sensors and fail to anticipate low friction roads ahead.
Innovation Solution
A control apparatus and method that utilize both contact-based and contactless sensors to calculate road surface friction coefficients, allowing for real-time adjustments in braking and driving forces by determining the friction coefficient of the current road surface and anticipating low friction surfaces ahead, thereby stabilizing vehicle behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only contact-based sensors are used to estimate road surface friction coefficients, then the system is simple, but the vehicle behavior becomes unstable when transitioning from high to low friction surfaces
Solution Approach 1:
The patent combines contact-based sensors (wheel speed sensors, acceleration sensors) with contactless sensors (cameras, LIDAR, infrared sensors) to create a hybrid sensing system. This merging allows the system to capture both current vehicle state data and future road condition data, improving reliability of friction coefficient estimation without excessive complexity increase
Solution Approach 2:
The contactless sensors detect road surface conditions ahead of the vehicle before the vehicle actually reaches those surfaces. This preliminary detection allows the control system to prepare for upcoming friction changes, maintaining stability during transitions from high to low friction surfaces by anticipating conditions before they affect vehicle behavior
2Loss of information
If contactless sensors are added to detect future road conditions, then the vehicle can anticipate low friction surfaces, but the device complexity increases
Solution Approach 1:
The control system integrates multiple sensor types that serve both current monitoring and future prediction functions. The same processing unit that handles contact-based sensor data also processes contactless sensor data, and the control algorithms manage both present and anticipated road conditions, reducing overall system complexity through multi-functionality
Solution Approach 2:
The patent introduces a road surface friction coefficient calculation unit that acts as an intermediary, synthesizing data from both contact-based and contactless sensors. This mediator processes raw sensor data, estimates current friction coefficients, and predicts future friction conditions, reducing the complexity burden on the main control system while improving information accuracy
3Reliability
If the system relies solely on current friction coefficient data, then the control system is simple, but it cannot anticipate low friction roads ahead causing unstable behavior
Solution Approach 1:
Contactless sensors positioned to view the road ahead capture images and data about upcoming surface conditions before the vehicle reaches them. This preliminary action allows the system to detect future low friction roads and adjust control parameters in advance, improving reliability during transitions
Solution Approach 2:
The system continuously compares detected road conditions with predicted conditions, and the control unit adjusts braking and driving forces based on this feedback loop. When discrepancies indicate upcoming friction changes, the system proactively modifies control parameters, improving reliability while managing the complexity of future condition detection
Data Source
AI summary
A control apparatus for a vehicle includes: a first road surface friction coefficient calculator; a second road surface friction coefficient calculator; and a braking and driving force controller. The first road surface friction coefficient calculator calculates a first road surface friction coefficient that is a friction coefficient of a road surface in a contact with a wheel. The second road surface friction coefficient calculator calculates a second road surface friction coefficient on a basis of a detection value from a contactless sensor that contactlessly detects a road surface state.