Traffic Light State Detection Using LiDAR Motion Patterns

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional approaches for vehicles to determine traffic light states are prone to errors due to sub-optimal camera settings, poor image quality from dirt, weather conditions, and obstructions, leading to unreliable recognition of traffic lights and their states.

Innovation Solution

A system that interprets traffic light states based on observed traffic patterns using a neural network trained with three-dimensional data from LiDAR, radar, and image data, combining semantic maps and image processing techniques to provide accurate predictions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If image processing techniques are used to detect traffic light states, then the system can identify traffic lights, but the detection accuracy deteriorates due to poor image quality from dirt, weather conditions, and obstructions

Engineering Contradiction:
Improvetraffic light state detection reliabilityVSAvoidtraffic light state recognition precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system segments the traffic light detection task into multiple independent analysis streams: image data processing, LiDAR point cloud analysis for traffic motion patterns, and radar data processing. Each sensor type processes specific aspects of the environment, and their results are integrated to form a comprehensive traffic light state determination, reducing dependency on any single degraded sensor input.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system merges data from multiple sensor types (cameras, LiDAR, radar) to create a multi-modal perception system. By combining image data with three-dimensional spatial data and traffic motion patterns, the system compensates for deficiencies in individual sensors, particularly when image quality is degraded by environmental factors.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If conventional camera-based approaches are used, then the system structure remains simple, but detection accuracy deteriorates due to sub-optimal camera settings and environmental factors

Engineering Contradiction:
Improvetraffic light state detection accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system implements multi-functional sensors that serve multiple purposes: LiDAR point clouds are used both for creating three-dimensional environmental models and for analyzing traffic motion patterns; radar data serves both obstacle detection and traffic flow analysis. This multi-functionality justifies the added complexity by maximizing the utility of each sensor component.

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

Solution Approach 2:

The system transitions from two-dimensional image processing to three-dimensional spatial analysis by incorporating LiDAR point cloud data. This dimensional enhancement allows the system to analyze traffic motion patterns in three-dimensional space, providing more robust traffic light state prediction that is less susceptible to image quality degradation.

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

3Reliability

If the system uses multiple sensors and data processing techniques, then detection reliability improves, but computational complexity and processing time increase

Engineering Contradiction:
Improvetraffic light state detection reliabilityVSAvoiddata processing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary processing of sensor data to extract essential features before integration: LiDAR data is pre-processed to identify traffic motion patterns, image data is pre-processed to locate potential traffic lights, and radar data is pre-processed to detect moving objects. This preliminary action reduces the complexity of the subsequent integration step by presenting refined, organized data streams.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms where the predicted traffic light state and traffic motion patterns are continuously refined based on incoming sensor data. The neural network model receives feedback from multiple data streams and adjusts its predictions accordingly, allowing the system to maintain high reliability while managing computational complexity through iterative refinement rather than exhaustive processing.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11170238B2Approaches for determining traffic light state
Publication Date: 2021.11.09 WOVEN BY TOYOTA U S INC
  • US11170238B2 patent drawing
  • US11170238B2 patent drawing
  • US11170238B2 patent drawing

AI summary

Systems, methods, and non-transitory computer-readable media can determine sensor data captured by at least one sensor of a vehicle over a set of time intervals while navigating an environment. Three-dimensional data describing the environment over the set of time intervals can be determined from the captured sensor data. The three-dimensional data capturing a traffic motion pattern for at least one direction of travel. Image data of at least one traffic light in the environment can be determined over the set of time intervals from the captured sensor data. A state of the at least one traffic light can be predicted based at least in part on the three-dimensional data describing the environment and the image data of at least one traffic light in the environment over the set of time intervals.