Radar Mapping Localization for GPS-Denied Autonomous Driving

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Solution Overview

Problem

Current radar systems in autonomous vehicles face challenges in accurately determining location and navigating without relying on GPS or other location services, particularly when operating in environments with varying roadside features.

Innovation Solution

The implementation of a radar system that transmits and receives multiple pulses while in motion, using Synthetic Aperture Radar (SAR) mode to gather high-resolution data on roadside features, which is then correlated with map data to determine vehicle location and control autonomous navigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar systems transmit and receive multiple signal pulses while in motion to gather high-resolution data on roadside features, then measurement precision of location is improved, but device complexity increases due to SAR mode implementation

Engineering Contradiction:

Improvelocation determination accuracyVSAvoidradar system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system pre-processes radar reflection signals from multiple pulses to create correlated target information before comparing with map data. This preliminary processing of reflection signals while the vehicle is in motion enables accurate location determination without requiring complex real-time processing during navigation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses map data as an intermediary to bridge the radar measurements and location determination. The correlated target information from radar reflections is compared against predetermined map data, allowing the system to achieve high measurement precision while keeping the radar system itself relatively simple

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the radar system operates in SAR mode to create high-resolution maps of roadside features, then reliability of autonomous navigation is improved, but use of energy increases due to multiple signal pulses

Engineering Contradiction:

Improveautonomous navigation reliabilityVSAvoidradar energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The radar system transmits signal pulses periodically rather than continuously, which reduces energy consumption while still gathering sufficient data for reliable location determination. The multiple pulses are transmitted at intervals and processed to create correlated target information for comparison with map data

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If the system correlates target information with predetermined map data to determine vehicle location, then adaptability to GPS-denied environments is improved, but loss of time increases due to processing requirements

Engineering Contradiction:

Improveoperation without GPSVSAvoidprocessing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs preliminary correlation of target information with map data during the data gathering phase while the vehicle is in motion. This advance processing enables the system to adapt to GPS-denied environments without requiring time-consuming processing during critical navigation moments

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables accurate location determination and autonomous navigation by creating a high-resolution map of roadside features, allowing the vehicle to operate effectively without GPS, enhancing safety and operational efficiency.

Implementation Method 1

Distances to radio-reflective features can be determined according to the time delay between transmission and reception

Methodology Applied

Scientific EffectTime of Flight: Time of Flight

Implementation Method 2

Some systems may also estimate relative motion of reflective objects based on Doppler frequency shifts in the received reflected signals

Methodology Applied

Scientific EffectDoppler Effect: Doppler Effect

Implementation Method 3

Some example automotive radar systems may be configured to operate at an electromagnetic wave frequency of 77 Giga-Hertz (GHz), which corresponds to millimeter (mm) electromagnetic wave lengths

Methodology Applied

Scientific EffectElectromagnetic Radiation:

Data Source

PatentUS11835624B2Radar based mapping and localization for autonomous vehicles

Publication Date: 2023.12.05 WAYMO LLC

AI summary

In an example method, a vehicle configured to operate in an autonomous mode could have a radar system used to aid in vehicle guidance. The method could include transmitting at least two signal pulses. The method further includes, for each transmitted signal pulse, receiving a reflection signal associated with reflection of the respective transmitted signal pulse. Each reflection signal may be received when the apparatus is in a different respective location. Additionally, the method includes processing the received reflection signals to determine target information relating to one or more targets in an environment of the vehicle. Also, the method includes correlating the target information with at least one object of a predetermined map of the environment of the vehicle to provide correlated target information. Yet further, the method includes storing the correlated target information for the at least one object in an electronic database.