Reference Trajectory Generation by Clustering Normal Vehicle Paths

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Solution Overview

Problem

Existing reference trajectory generation methods may produce inappropriate reference trajectories due to the inclusion of unnatural vehicle trajectories, which can affect autonomous driving systems, as these trajectories are not representative of normal vehicle travel patterns.

Innovation Solution

A reference trajectory generating device that classifies vehicle trajectories by clustering and selects the most common class to generate a reference trajectory, excluding abnormal or prohibited trajectories, using road structure data to refine the clustering process and averaging individual trajectories within the selected class.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If all vehicle trajectories are used for generating reference trajectory, then more trajectory data is available for processing, but the reference trajectory becomes inappropriate due to inclusion of unnatural trajectories

Engineering Contradiction:
Improvenumber of trajectoriesVSAvoidquality of reference trajectory
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent extracts and removes unnatural trajectories from the dataset before generating the reference trajectory. By identifying and excluding trajectories that deviate from normal driving patterns (such as those with excessive lateral acceleration or improbable path deviations), the system ensures that only representative natural trajectories are used, thereby maintaining high reliability while processing a substantial quantity of valid data.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different quality standards to different segments of trajectories. Rather than uniformly accepting or rejecting entire trajectories, the system evaluates local characteristics (such as lateral acceleration, curvature, and speed variations) at specific segments and selectively filters out only the unnatural portions, preserving the majority of valid trajectory data while eliminating problematic sections.

Inventive Principle:
Principle #3Local quality

2Reliability

If clustering is applied to classify trajectories, then natural trajectories can be identified, but the processing complexity increases

Engineering Contradiction:
Improveaccuracy of trajectory selectionVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the trajectory classification process into distinct stages: first filtering trajectories based on basic naturalness criteria (lateral acceleration thresholds, speed ranges), then applying clustering algorithms only to the pre-filtered subset. This segmentation reduces the computational burden of clustering while maintaining accurate identification of natural trajectories.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary filtering and preprocessing of trajectories before applying clustering algorithms. By pre-processing the data to remove obviously unnatural trajectories and normalize the remaining data, the system reduces the complexity and computational resources required for the subsequent clustering step, while still achieving reliable identification of natural driving patterns.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20240253662A1Reference trajectory generating device, method, and computer program for generating reference trajectory
Publication Date: 2024.08.01 WOVEN BY TOYOTA INC
  • US20240253662A1 patent drawing
  • US20240253662A1 patent drawing
  • US20240253662A1 patent drawing

AI summary

A reference trajectory generating device includes a processor configured to classify a plurality of trajectories of travel of at least one vehicle through a predetermined section of a road into a plurality of classes by clustering of the trajectories in the predetermined section, select a class including the most trajectories of the classes, and generate a reference trajectory serving as a reference in the predetermined section by averaging individual trajectories included in the class selected from the classes.