Road Friction Estimation Using Sensor Fusion

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Solution Overview

Problem

Autonomous vehicles face challenges in safely navigating through varying weather conditions due to uncertainties in road friction, which can lead to hazardous driving situations, especially when precipitation is involved.

Innovation Solution

The system estimates road friction by combining data from temperature sensors, cameras, and vehicle systems like ABS and TCS, using image processing and weather reports to determine friction ranges and adjust vehicle operations such as speed, acceleration, and steering to ensure safe driving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the vehicle operates without real-time road friction estimation, then the system complexity is reduced, but the safety and reliability deteriorate due to uncertainties in varying weather conditions

Engineering Contradiction:
ImprovesafetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system continuously estimates road friction by processing sensor data (temperature, precipitation, camera images) and vehicle behavior data (ABS engagement, TCS engagement, deceleration events) and feeds this information back to adjust driving operations in real-time, improving safety through adaptive control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control computer performs multiple functions: it processes environmental sensor data, analyzes camera images for precipitation detection, monitors vehicle system states (ABS, TCS), estimates road friction, and adjusts driving operations, consolidating these diverse functions into a single multi-functional system

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If the system uses multiple sensors and data sources to estimate road friction, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improvefriction estimation accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system merges data from multiple sources including temperature sensors, precipitation sensors, camera systems, and vehicle behavior sensors into a unified road friction estimation model, combining these inputs to achieve more accurate friction measurement than any single sensor could provide

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control computer acts as an intermediary that processes and integrates data from various sensors and vehicle systems, transforming raw sensor inputs into meaningful friction estimates that guide driving operations

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the vehicle adapts its operations based on real-time friction estimates, then the reliability improves, but the ease of operation decreases due to reduced driver control

Engineering Contradiction:
ImprovesafetyVSAvoiddriver control
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically adjusts driving operations based on real-time road friction estimates, modifying acceleration, deceleration, and steering behaviors adaptively according to current road conditions, enabling the vehicle to respond flexibly to changing environmental factors

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11639177B2Road friction estimation techniques
Publication Date: 2023.05.02 CREATEAI INC
  • US11639177B2 patent drawing
  • US11639177B2 patent drawing

AI summary

Techniques are described for estimating road friction between a road and tires of a vehicle. A method includes receiving, from a temperature sensor on a vehicle, a temperature value that indicates a temperature of an environment in which a vehicle is operated, determining a first range of friction values that quantify a friction between a road and tires of a vehicle based on a function of the temperature value and an extent of precipitation in a region that indicate a hazardous driving condition, obtaining, from the first range of friction values, a value that quantifies the friction between the road and the tires of the vehicle, where the value is obtained based on a driving related behavior of the vehicle, and causing the vehicle to operate on the road based on the value obtained from the first range of friction values.