[AD Fundamentals] High-Definition Maps

Authored by Tony Feng

Created on Oct 29th, 2022

Last Modified on Oct 30th, 2022

Intro

This sereis of posts contains notes from the course Self-Driving Fundamentals: Featuring Apollo published by Udacity & Baidu Apollo. This course aims to deliver key parts of self-driving cars, including HD Map, localization, perception, prediction, planning and control. I posted these “notes” (what I’ve learnt) for study and review only.


HD Maps

  • Accurate 3D representation of the road network
    • e.g. layout of intersections, locations of signposts
  • Semantic info
    • e.g. traffic light, speed limit, lane rules
  • 3D model of the city
    • e.g. roads, buildings, tunnels

Localization, Percpeption and Planning

Localization with HD Maps

  • Comparisons between observed data and data in the HD map
  • Preprocessing, coordinate transformation, data fusion

Perception with HD Maps

  • HD maps help the car’s next decions.
    • Sensors have limits in different situations
    • Camera is affected by bad whether and dark environment.
    • Other sensors may not detect what is behind the obstacle.
  • HD maps can narrow the detection scope.
    • Region of Interest (ROI) helps improve speed and accuracy.
    • Region of Interest (ROI) helps to save the computation resources.

Planning with HD Maps

  • HD Maps help to find suitable driving space.
  • HD Maps help to identify different possible routing options and find best maneuver.
  • HD Maps help to forecast future locations for other vehicles on the road.

Apollo HD Maps

Road Definitions

Standard vs. Apollo OpenDRIVE

Main Difference Standard OpenDRIVE Apollo OpenDRIVE
Application Scenario Simulation scenarios Real-world scenes
Elemental Form Expression Reference line Absolute coordinate sequences
Elemental Richness Common elements More expressions and attributes
Adaptive Driverless Algorithm N/A Integrate Baidu’s driverless experience

HD Maps Construction

  • Data Sourcing
    • Survey vehicle with GPS, IMU, Antenna, LiDAR, Camera
    • Crowdsourcing with mobile devices, in-car devices, connected cars, etc.
  • Data Processing
    • Form an inital map template by data sorting, classfiying, cleansing
    • Without semantic info and annotations
  • Object Detection
    • Detect and classify static objects
  • Manual Verification
    • Ensure the automated map creation correctly
  • Map Products
    • Top-down view localication maps
    • 3D point cloud maps

MIT License
Last updated on Oct 31, 2022 13:54 EDT
Built with Hugo
Theme Stack designed by Jimmy