Cross-Sensor Ground Truth Transfer for Recognizer Training

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Solution Overview

Problem

The manual annotation of ground truth data for machine learning in autonomous driving vehicles is time-consuming and costly, especially when sensor configurations are updated, requiring re-collection and re-annotation of large data sets.

Innovation Solution

A method and system that automatically generates ground truth data by using the recognition results from a first sensor to annotate and project onto the data of a second sensor with a different modality, leveraging coordinate transformations and calibration to align sensor systems, thereby facilitating machine learning for the second sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual annotation is performed to create ground truth data for machine learning, then the accuracy and quality of training data is improved, but the time consumption and cost increase significantly

Engineering Contradiction:
Improveground truth data qualityVSAvoidannotation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary annotation using the first recognizer on the first sensor data, and stores these recognition results. When ground truth data is needed for the second sensor, the pre-computed recognition results are transformed and projected onto the second sensor data, eliminating the need for real-time manual annotation and significantly reducing time consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The recognition results obtained from the first sensor data are copied and transformed to serve as ground truth annotations for the second sensor data. Instead of creating annotations from scratch for each sensor, the system copies the semantic information from the first recognizer's output, transforms it to the second sensor's coordinate system, and uses it as ground truth, thereby reducing repetitive manual work.

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If sensor configuration is updated with replacement or new installation, then the system can utilize improved or additional sensing capabilities, but the ground truth data must be re-collected and re-annotated

Engineering Contradiction:
Improvesensor configuration flexibilityVSAvoiddata preparation efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The recognition results from the first sensor are designed to be universally applicable to multiple sensor types through coordinate transformation and projection. The system transforms the recognition results to match the coordinate systems of different sensor configurations (camera, LiDAR, radar), allowing the same annotated data to serve multiple sensor modalities without requiring separate annotation processes for each sensor type.

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

Solution Approach 2:

The system changes the coordinate system parameters and projection parameters to adapt the recognition results from the first sensor to the second sensor's configuration. By adjusting transformation matrices, coordinate references, and projection geometries, the system makes the ground truth data compatible with different sensor configurations without re-annotation, maintaining productivity during sensor updates.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If ground truth data is manually annotated for each sensor individually, then the accuracy for each specific sensor is ensured, but the overall process complexity and resource requirements increase

Engineering Contradiction:
Improvesensor-specific annotation accuracyVSAvoidannotation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system merges the annotation process for multiple sensors into a single unified process. Instead of performing separate manual annotations for each sensor, the recognition results from one sensor are transformed and projected onto multiple sensors simultaneously. This combining of annotation efforts reduces system complexity while maintaining the accuracy needed for each sensor type through proper coordinate transformation.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS12608951B2Method and system for generating ground truth data for machine learning of recognizer
Publication Date: 2026.04.21 TOYOTA JIDOSHA KK
  • US12608951B2 patent drawing
  • US12608951B2 patent drawing
  • US12608951B2 patent drawing

AI summary

According to the present method, first, first surrounding environment data is acquired by a first sensor. Next, second surrounding environment data is acquired by a second sensor at a same time as an acquisition time of the first surrounding environment data in a same region as an acquisition region of the first surrounding environment data. Next, first recognition result is acquired by inputting the first surrounding environment data into a first recognizer machine-learned using surrounding environment data acquired by the first sensor. Next, the first recognition result is projected onto the second surrounding environment data by transformation from a coordinate system of the first sensor to a coordinate system of the second sensor. Then, ground truth data for machine-learning a second recognizer configured to recognize surrounding environment data acquired by the second sensor is generated based on the second surrounding environment data onto which the first recognition result is projected.