Dual-Return LiDAR Vapor Detection for False Object Filtering

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Solution Overview

Problem

Autonomous vehicles often incorrectly detect vapor as objects due to opaque lidar data, leading to unnecessary stops or maneuvers, as conventional approaches fail to differentiate vapor from other objects using single return lidar data.

Innovation Solution

The use of dual return lidar data, including a strongest and farthest lidar return, to identify vapor in the driving environment, with a neural network determining object types and controlling vehicle systems to ignore vapor, allowing the vehicle to pass through without stopping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional single return lidar data is used to detect objects, then the autonomous vehicle can detect objects in the driving environment, but the autonomous vehicle incorrectly identifies vapor as objects leading to unnecessary stops

Engineering Contradiction:
Improveobject detection accuracyVSAvoidunnecessary stopping time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the lidar return data into multiple components (strongest return, farthest return, and intermediate returns) to analyze different reflection sources. By examining the distribution and characteristics of these segmented returns, the system can distinguish vapor reflections from actual object reflections, thereby improving detection accuracy and avoiding unnecessary stops

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an additional dimension of analysis by comparing multiple lidar returns (not just the strongest one) along the range dimension. This multi-dimensional approach to analyzing return intensity distributions enables the system to identify vapor patterns that single-point detection cannot detect, resolving the contradiction between detection reliability and time loss

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the autonomous vehicle stops to avoid detected vapor, then the vehicle may avoid potential hazards, but the vehicle loses navigation efficiency and may require extended stopping periods

Engineering Contradiction:
Improvesafety of navigationVSAvoidnavigation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements feedback by continuously monitoring lidar return patterns and using neural networks to classify detected features as vapor or actual objects. This feedback mechanism enables real-time differentiation between safe vapor detections and hazardous objects, allowing the vehicle to maintain navigation efficiency while ensuring safety through accurate classification

Inventive Principle:
Principle #23Feedback

3Difficulty of detecting and measuring

If the autonomous vehicle uses lidar data to detect all reflective surfaces, then comprehensive object detection is achieved, but vapor is incorrectly classified as solid objects requiring avoidance

Engineering Contradiction:
Improvedetection completenessVSAvoidobject type classification accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent changes the parameters used for object classification by analyzing multiple characteristics of lidar returns including intensity distribution across multiple returns, range values, and reflection patterns. These parameter changes enable the neural network to distinguish vapor from solid objects with high precision while maintaining comprehensive detection of all reflective surfaces

Inventive Principle:
Principle #35Parameter changes

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 effectively mitigates false object detection by vapor, enabling autonomous vehicles to navigate through steam and other vapors without unnecessary stops, improving navigation efficiency and reducing human intervention.

Implementation Method 1

Vapor can reflect a light beam emitted by the lidar sensor system, which can result in a lidar return having a relatively high intensity corresponding to a location of the vapor

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentUS11994589B2Vapor detection in lidar point cloud
Publication Date: 2024.05.28 GM CRUISE HOLDINGS LLC
  • US11994589B2 patent drawing
  • US11994589B2 patent drawing
  • US11994589B2 patent drawing

AI summary

Various technologies described herein pertain to detecting data in a lidar point cloud representative of vapor and controlling an autonomous vehicle based on such detection. The lidar point cloud is outputted by a lidar sensor system of the autonomous vehicle. The techniques set forth herein utilize dual return lidar data outputted by the lidar sensor system. The dual return lidar data includes two lidar returns received responsive to a light beam emitted (e.g., at a particular azimuthal angle) by the lidar sensor system into a driving environment of the autonomous vehicle. The data in the lidar point cloud detected as being caused by vapor can be removed from downstream processing; accordingly, the autonomous vehicle can be controlled such that the autonomous vehicle need not stop for or maneuver around vapor in the driving environment.