Vehicle Speed Proposal Using Real-Time Grip Potential Estimation

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Solution Overview

Problem

Current driving assistance systems fail to accurately estimate tire-road grip potential in real-time, especially in conditions with low grip levels, and are unable to account for complex driving maneuvers, leading to insufficient safety margins.

Innovation Solution

A method that estimates tire-road grip potential by determining influential parameters such as road texture, water depth, and tire conditions, using mathematical models and charts, and selects a secure driving style to propose an optimized speed for the driver, ensuring comfort and safety by interpolating speed profiles based on GPS location and predetermined routes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If grip potential is estimated by stressing it up to half the maximum potential, then the grip potential can be determined, but the safety margin for the driver is insufficient

Engineering Contradiction:
Improvegrip potential estimation accuracyVSAvoidsafety margin
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary estimation of the maximum grip potential before actual driving maneuvers occur. By using measured parameters (road texture, water depth, temperature) and tyre features to calculate the grip number in advance, the system establishes a safety margin before the driver needs to react, rather than waiting to stress the grip potential during critical moments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention introduces an intermediary computational model that processes multiple measured parameters (road grip number, sand patch depth, water depth, temperature, tyre features) to derive the maximum grip potential. This intermediary system acts as a mediator between raw sensor data and safety-critical speed recommendations, enabling accurate estimation without direct stress testing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If vehicle equilibrium models and trajectory tracking hypotheses are used, then grip potential can be estimated, but the system cannot account for complex driving maneuvers and driver behavior

Engineering Contradiction:
Improvegrip potential estimationVSAvoidcomplex maneuver handling
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system changes from using fixed trajectory tracking hypotheses to dynamically adjusting the grip number based on measured parameters. By continuously updating the grip number according to actual road conditions (water depth, texture, temperature) and tyre state, the system adapts to complex maneuvers without relying on predetermined cartographic trajectories that cannot capture real-world driving complexity.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple parameters are measured and processed in real-time, then accurate grip potential estimation is achieved, but the computational complexity increases

Engineering Contradiction:
Improvegrip potential estimation accuracyVSAvoidcomputational system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The computational system is segmented into distinct functional modules: a measurement module that collects parameters (road texture, water depth, temperature, tyre features), a computation module that calculates the grip number using these parameters, and an application module that uses the grip number for speed recommendations. This segmentation allows each module to be optimized independently, reducing overall system complexity while maintaining measurement precision.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11390292B2Method for proposing a driving speed
Publication Date: 2022.07.19 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • US11390292B2 patent drawing
  • US11390292B2 patent drawing
  • US11390292B2 patent drawing

AI summary

A method for proposing a driving speed for a driver at the steering wheel of a vehicle comprises the following steps: estimating the maximum available grip potential at a given instant between a tyre of the vehicle and the roadway on a predetermined upcoming route; determining, among a set of predetermined driving styles, secure styles for which the grip requirement on the predetermined route remains lower than the grip potential; selecting, among said secure styles, a secure comfortable style according to a driver profile; and determining, according to said secure comfortable style and to a location of the vehicle, a basic proposed driving speed on an upcoming section of route.