Trajectory Prediction Mode Identification for ADAS

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Solution Overview

Problem

Existing methods for predicting future trajectories of road users in AD/ADAS and Industry 4.0 applications face challenges due to ambiguity in mode definitions, leading to unstable learning processes and unclear interpretability, especially in scenarios like T-intersections where multiple modes are predicted without clear distinctions, affecting user experience and training stability.

Innovation Solution

The solution involves identifying modes in a second feature space with interpretable latent representations, using an adaptive loss function to prevent inter-mode averaging and allow for a variable number of modes per input, where the distance between ground truth and output is minimized based on latent representations rather than traditional distances, and employing machine learning models to generate trajectory predictions that satisfy specific characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple future modes are predicted without defining clear mode distinctions, then the coverage of possible trajectories is improved, but the interpretability and stability of the learning process deteriorate

Engineering Contradiction:
Improvecoverage of possible trajectoriesVSAvoidstability of learning process
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the continuous trajectory prediction problem into discrete mode categories. By introducing a mode identification module that classifies trajectories into distinct modes (e.g., going straight, turning left, turning right), the system maintains multiple possible outcomes while providing clear distinctions between them. This segmentation enables both comprehensive coverage and interpretability through defined mode boundaries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces mode definitions and mode probabilities as intermediary elements between the input trajectory history and the output predictions. These intermediaries serve as explicit representations that bridge the gap between multiple possible futures and interpretable results, allowing the system to maintain versatility while improving reliability through structured mode classification.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If mode definitions are made explicit and interpretable, then the interpretability and training stability are improved, but the complexity of the system increases

Engineering Contradiction:
Improvetraining stabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system is segmented into distinct functional modules: trajectory prediction, mode identification, and probability calculation. This modular segmentation manages complexity by organizing the system into manageable components, each with a specific function, while maintaining the benefits of explicit mode definitions for improved stability and interpretability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mode identification module serves multiple functions simultaneously: it provides interpretability through defined modes, stabilizes training by reducing ambiguity, and enables probability calculation for different modes. This multi-functionality justifies the added complexity by delivering multiple benefits from a single modular component.

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

3Productivity

If a fixed number of modes is used for prediction, then the computational efficiency is improved, but the adaptability to different scenarios deteriorates

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidadaptability to scenarios
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The system dynamically determines the number and types of modes based on the input trajectory history and environmental context. Rather than using a fixed number of modes, the mode identification module adapts its output to match the specific scenario, allowing the system to maintain computational efficiency while achieving high adaptability to different driving situations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the mode parameters (number of modes, mode types, probability distributions) based on the input scenario. This parameter adaptation allows the model to efficiently handle diverse situations by adjusting its predictive framework to match the specific context, whether that involves a few clear modes or many possible outcomes.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4224436A1Method and computer program for characterizing future trajectories of road users
Publication Date: 2023.08.09 ZF FRIEDRICHSHAFEN AG
  • EP4224436A1 patent drawingFigure 1~2
  • EP4224436A1 patent drawingFigure 3
  • EP4224436A1 patent drawingFigure 4

AI summary

A method for characterizing future trajectories (Y) of road users comprising the steps of: obtaining trajectory histories of the road users and environmental features of a current traffic scene as an input (X) (V1); for each road user, determining an embedding (E) of trajectory and/or environmental features related to that road user in a first feature space (V2); mapping the image space of the embedding (E) onto a second feature space (C) (V3) comprising a first number (Nc) of characteristics (C[i]), each of which characterizes the future trajectories (Y) for that road user; a list (P) whose length is equal to the first number (Nc) and whose entries each specify probabilities (P[i]) for the occurrence of one of the future trajectories (Yi) with the respective characteristics (C[i]); predicting trajectories (Y) for that road user (V4);Determine whether the trajectory predictions (Y) are based on different characteristics (C[i]) or are realizations of the same characteristic (C[i]) (V5).;