Radar Lidar Confidence Score Calibration for Automated Driving

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Solution Overview

Problem

Current automatic vehicle steering systems face challenges in accurately classifying radar and lidar data due to over-confidence in predictions, noise, interference, and ambiguity in object recognition, leading to potential incorrect actions that could result in damage or injury.

Innovation Solution

A method that uses a classifier to map radar or lidar data to confidence scores, followed by a post-hoc calibration process to adjust these scores for better accuracy, and determines actuation signals based on these calibrated scores to ensure appropriate vehicle actions, while also considering the severity of potential collisions and fusing data from multiple sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a classifier is trained with one-hot ground truth labels to improve classification speed, then classification speed is improved, but classification accuracy deteriorates due to over-confidence in predictions

Engineering Contradiction:
Improveclassification speedVSAvoidclassification accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing post-hoc calibration on the classifier's confidence scores after the initial classification. The calibration process adjusts the over-confident predictions by comparing them with actual classification accuracy metrics, thereby correcting the over-confidence issue without retraining the classifier. This maintains the speed advantage while improving accuracy.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If confidence scores are used to determine vehicle actions to improve response time, then response time is improved, but reliability deteriorates due to over-confidence leading to incorrect actions

Engineering Contradiction:
Improveresponse timeVSAvoidaction reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent implements feedback by using the calibrated confidence scores (which reflect actual classification accuracy) to determine vehicle actions. The calibration process provides feedback on the true reliability of each classification, allowing the system to make more reliable decisions. This feedback mechanism ensures that actions are taken based on accurate confidence assessments rather than over-confident predictions.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the classifier outputs high confidence scores for all predictions to improve decision-making, then decision-making is simplified, but trustworthiness deteriorates due to mismatch between confidence and actual accuracy

Engineering Contradiction:
Improvedecision-making simplicityVSAvoidtrustworthiness of classification
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies parameter changes by transforming the confidence scores through a calibration function that adjusts them to match actual classification accuracy. Instead of outputting raw high confidence scores, the system transforms these scores into calibrated values that accurately reflect the true reliability. This maintains the simplicity of using confidence scores for decision-making while restoring trustworthiness through parameter transformation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4080240A1Improved evaluation of radar or lidar data with reduced classification over-confidence
Publication Date: 2022.10.26 ROBERT BOSCH GMBH
  • EP4080240A1 patent drawingFigure 1
  • EP4080240A1 patent drawingFigure 2a~2b
  • EP4080240A1 patent drawingFigure 3

AI summary

A method (100) for evaluating at least one record of radar or lidar data (2), wherein the data (2) comprises the dependence of at least one measurement quantity that has been derived from reflected radar or lidar radiation on spatial coordinates, the method comprising the steps of: • mapping (110), by means of a given classifier (1), the record of radar or lidar data (2) to a set of confidence scores (3) with respect to classes of a given classification; • processing (120) the set of confidence scores (3), and/or an intermediate product from which the classifier computes confidence scores (3), by means of a post-hoc calibration operation (4) that is configured to match the confidence scores (3) to the classification accuracy (1a) of the classifier (1) with respect to the record of radar or lidar data (2); and • outputting (130) the so-processed set of confidence scores (3), and/or a set of confidence scores (3) that results from the so-processed intermediate product, as an evaluation result (3*) of the record of radar or lidar data (2). A method (200) for training at least one post-hoc calibration operation (4) for use in the method (100).