LiDAR Road Surface Estimation Using Reflectance Heat Maps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Autonomous vehicles face challenges in accurately determining road surface conditions, which is crucial for safe navigation, as existing technologies lack effective methods to differentiate between various surface conditions such as dry, wet, snowy, or icy surfaces, especially under varying light conditions.

Innovation Solution

A system utilizing a LiDAR sensor to emit pulsed light waves and determine reflectance values and distances, generating a heat map to differentiate between surface conditions by comparing received returns with pre-defined distributions and indexes, allowing for the identification of dry, moist, slushy, wet, snowy, or icy surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If LiDAR sensor is used to obtain reflectance values and distances, then measurement precision of surface conditions is improved, but device complexity increases

Engineering Contradiction:
Improvesurface condition differentiation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the road surface analysis into multiple discrete parameters: reflectance values, distance measurements, and return counts. Each parameter is measured independently by the LiDAR sensor and then processed separately through heat map generation and statistical analysis, allowing complex surface condition differentiation to be achieved through multiple simple, modular measurements rather than a single complex measurement system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces heat maps as an intermediary representation between raw LiDAR data and surface condition determination. The heat map visually encodes reflectance values and distance information, serving as a mediator that transforms complex multi-dimensional sensor data into an interpretable format that can be easily compared against reference distributions for different surface conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If heat map generation is implemented to differentiate surface conditions, then information completeness is improved, but loss of time increases

Engineering Contradiction:
Improvesurface condition information completenessVSAvoidprocessing time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores reference heat maps and return count distributions for various known surface conditions (dry, wet, snowy, icy) before actual road analysis is needed. When analyzing a road surface, the system simply compares the generated heat map against these pre-computed references using statistical tests, avoiding the need to perform complex simulations or calculations in real-time and significantly reducing processing time.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple returns are analyzed to determine surface condition, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvesurface condition determination accuracyVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent analyzes multiple LiDAR returns (excessive action) to determine surface conditions, using statistical measures such as return counts and heat map patterns. By collecting more data points than the minimum single measurement, the system achieves higher confidence and accuracy in surface condition determination, using statistical over-sampling to overcome the limitations of individual measurements that may be affected by noise or anomalies.

Inventive Principle:
Principle #16Partial or excessive action

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

Enables accurate and real-time estimation of road surface conditions, enhancing safety by providing vehicles with critical information for navigation and control adjustments, regardless of natural light availability.

Implementation Method 1

The sensor component can emit one or more pulsed light waves that reflect off a surface of the road to be received by the sensor component to determine the distance between the surface and a vehicle

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a sensor component, comprising a LiDAR sensor, that can obtain a reflectance value and a distance associated with a portion of a road

Methodology Applied
Scientific EffectLIDAR: LIDAR

Data Source

PatentUS20240425054A1Estimating surface conditions on a road
Publication Date: 2024.12.26 VOLVO CAR CORP
  • US20240425054A1 patent drawing
  • US20240425054A1 patent drawing
  • US20240425054A1 patent drawing

AI summary

Various systems and methods are presented regarding estimating surface conditions on a road for a vehicle. Techniques are described for using reflectance values and distance to determine road surface conditions. In an example embodiment, a system, comprises a memory that stores computer executable components; and a processor that executes the computer executable components stored in the memory, wherein the computer executable components can comprise: a sensor component, comprising a LiDAR sensor, that can obtain a reflectance value and a distance associated with a portion of a road; a mapping component that can generate a heat map of the reflectance value and the distance; an indexing component that can determine a number of returns received from the sensor component indicating a surface condition of the road; and a road condition component that can determine the surface condition of the road from the heat map and the number of returns received.