Radar Object Tracking Using Road Topology Constraints

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Solution Overview

Problem

Vehicle perception systems, particularly those using radar, face challenges with noise from static objects and atmospheric conditions, leading to inaccurate object detection and tracking, as moving objects appear spread out and background noise causes positional shifts, making motion returns ineffective.

Innovation Solution

A processor-implemented method that organizes radar measurements into time-ordered clusters, removes noise by comparing them to a road topology map, and uses a constrained Kalman filter to track objects within aligned lanes, ensuring accurate detection and prediction of object movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar measurements are used for object detection and tracking, then object detection capability is provided, but noise from static objects and atmospheric conditions causes inaccurate detection and tracking

Engineering Contradiction:
Improveobject detection accuracyVSAvoidnoise from static objects and atmospheric conditions
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces road topology maps and lane information as intermediary data structures that mediate between raw radar measurements and object detection results. These intermediaries provide contextual constraints (valid regions, allowed directions of travel) that filter out noise from static objects and atmospheric conditions while preserving valid moving object detections.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter space by transforming radar measurements from raw coordinate data into constrained tracks that satisfy road topology constraints. By enforcing constraints on position (within lanes), direction (allowed directions of travel), and motion patterns (consistent with lane geometry), the system filters noise while maintaining detection accuracy.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If motion returns are used for tracking, then moving objects can be detected, but objects appear spread out over larger regions and positional shifts occur due to background noise

Engineering Contradiction:
Improveobject tracking reliabilityVSAvoidobject position accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously comparing radar measurements against road topology constraints and adjusting tracks accordingly. The constrained Kalman filter uses feedback from lane boundaries and allowed directions to correct positional drift and maintain accurate object tracking even in the presence of background noise.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by transforming uncertain radar measurements into constrained tracks with reduced positional uncertainty. By enforcing geometric constraints from road topology, the system reduces the spread of object positions and eliminates positional shifts caused by background noise.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If conventional radar tracking without constraints is used, then detection speed is maintained, but tracking accuracy deteriorates when objects move outside expected patterns

Engineering Contradiction:
Improvedetection speedVSAvoidtracking accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-computing road topology maps and lane constraints before radar detection occurs. These pre-computed constraints (valid regions, allowed directions, lane geometries) are ready to immediately constrain and correct radar measurements, enabling fast yet accurate tracking without sacrificing detection speed.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS10935652B2Systems and methods for using road understanding to constrain radar tracks
Publication Date: 2021.03.02 GM GLOBAL TECHNOLOGY OPERATIONS LLC
  • US10935652B2 patent drawing
  • US10935652B2 patent drawing
  • US10935652B2 patent drawing

AI summary

A processor-implemented method in a vehicle for detecting objects from radar data includes: retrieving radar measurements taken at different periodic time increments; organizing the radar measurements into appropriate time windows; building a sequence cluster of radar measurements wherein the sequence cluster comprises a sliding window the latest time windows of radar measurements; removing noise from the sequence cluster of radar measurements by removing a cluster of radar measurements from the sequence cluster of radar measurements that is contradictory to a road topology map for an area in which the first object is estimated to be situated; and outputting the sequence cluster of radar measurements after removal of contradictory radar measurements as a new cluster of radar measurements.