Temporal Voxel Occupancy Estimation Using Multi-Frame Aggregation

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Solution Overview

Problem

Existing perception systems in autonomous vehicles face challenges in accurately determining voxel occupancy due to noise and occlusions in single-frame image analysis, which can lead to inefficient and unsafe decision-making.

Innovation Solution

The method employs temporal multi-frame occupancy estimation using multiple camera frames to aggregate voxel features across time, incorporating a trained occupancy classifier and noise reduction techniques to enhance voxel occupancy estimation accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If single-frame image analysis is used for voxel occupancy determination, then processing speed is maintained, but accuracy deteriorates due to noise and occlusions

Engineering Contradiction:
Improvevoxel occupancy estimation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary occupancy estimation on historical frames before the current frame, creating a temporal baseline. This preliminary action allows the system to compare current occupancy estimates against historical data, filtering out noise and occlusions that would otherwise degrade measurement precision in single-frame analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous occupancy estimation across multiple frames rather than processing isolated frames. By continuously tracking voxel occupancy over time and aggregating features across frames, the system preserves useful temporal information while maintaining processing efficiency, thus improving accuracy without proportionally increasing complexity.

Inventive Principle:
Principle #20Continuity of useful action

2Measurement precision

If multiple camera frames are used for temporal multi-frame occupancy estimation, then accuracy improves, but processing time increases

Engineering Contradiction:
Improvevoxel occupancy estimation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system segments the processing task by identifying and focusing on changed voxels between frames rather than reprocessing all voxels. This segmentation allows the system to leverage temporal information from multiple frames for improved accuracy while minimizing redundant computations, thus reducing the time penalty associated with multi-frame processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs partial processing by aggregating voxel features only for changed regions across frames rather than processing the entire scene. This partial action approach maintains the accuracy benefits of temporal multi-frame analysis while significantly reducing the computational burden and processing time compared to exhaustive multi-frame processing.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If voxel features are aggregated across multiple frames, then noise and occlusion effects are reduced, but computational complexity increases

Engineering Contradiction:
Improveoccupancy estimation reliabilityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary identification of changed voxels between frames before aggregating features. This preliminary action creates a focused set of voxels that require aggregation, reducing the computational complexity of feature aggregation while maintaining the reliability benefits of temporal aggregation for noise and occlusion reduction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies different processing quality to different voxels based on their change status. Changed voxels receive full temporal aggregation processing for maximum reliability, while unchanged voxels are handled more efficiently. This local quality approach optimizes computational complexity by applying complex aggregation only where necessary while maintaining high reliability for critical occupancy determinations.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20250322668A1Temporal multi-frame occupancy estimation
Publication Date: 2025.10.16 GM GLOBAL TECHNOLOGY OPERATIONS LLC
  • US20250322668A1 patent drawing
  • US20250322668A1 patent drawing
  • US20250322668A1 patent drawing

AI summary

Examples described herein provide a method that includes receiving a first image captured by a camera of a vehicle at a first time t and receiving a second image captured by the camera of the vehicle at a second time t-1. The method further includes projecting each of a plurality of world voxels to the camera at the first time t and the second time t-1. The method further includes aggregating voxel features for the plurality of world voxels for the first image and the second image. The method further includes training an occupancy classifier using the aggregated voxel features.