System and method for radar based mapping for autonomous robotic devices

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Solution Overview

Problem

Current radar-based mapping techniques struggle to detect obstacles, especially transparent or reflective surfaces, and require large receiver arrays or mechanical scanning, limiting their effectiveness in indoor environments for mobile robots.

Innovation Solution

The use of radar reprojection techniques, which calculate the angle of detection by analyzing Doppler effects and phase differences between antenna signals, allowing for obstacle mapping without mechanical scanning and enabling detection of targets on both sides of the path, even in static environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If radar-based mapping techniques are used to detect obstacles, then detection capability is improved, but the ability to detect transparent or reflective surfaces deteriorates

Engineering Contradiction:
Improveobstacle detection capabilityVSAvoiddetection of transparent or reflective surfaces
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The patent replaces mechanical scanning radar systems with an electronic reprojection method. Instead of physically moving the radar antenna to scan the environment, the system uses signal processing techniques (reprojection algorithms) to calculate obstacle positions based on Doppler effects and phase differences from a stationary multi-antenna array. This substitution enables detection of transparent and reflective surfaces that were previously undetectable by conventional radar, while eliminating mechanical complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a composite signal processing approach that combines multiple radar signals from different antennas, integrates Doppler effect analysis with phase difference measurements, and merges reprojection calculations with traditional range-finding methods. This composite technique creates a robust detection system that overcomes the limitations of individual methods, particularly for detecting challenging surfaces like glass and metal.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If large receiver arrays or mechanical scanning are used to improve mapping accuracy, then measurement precision is improved, but device complexity deteriorates

Engineering Contradiction:
Improvemapping accuracyVSAvoidreceiver array size and mechanical scanning
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent eliminates mechanical scanning components by replacing them with an electronic reprojection algorithm. The system uses a stationary multi-antenna array combined with signal processing to achieve accurate mapping without any moving parts. This substitution maintains measurement precision while dramatically reducing device complexity and eliminating reliability issues associated with mechanical wear and failure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from spatial scanning (mechanical movement in physical space) to mathematical reprojection (computational processing in signal space). By transforming the problem from a physical scanning task to a computational reprojection task, the system achieves the same mapping accuracy using a fixed antenna array, thereby reducing mechanical complexity while maintaining precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Difficulty of detecting and measuring

If mechanical scanning is used to map the environment, then obstacle detection is improved, but the ability to detect targets on both sides of the path deteriorates

Engineering Contradiction:
Improveobstacle detectionVSAvoiddetection coverage on both sides
Core Design Contradiction:
Difficulty of detecting and measuringVSAdaptability or versatility

Solution Approach 1:

The patent divides the environment into multiple detection sectors, each monitored by a specific antenna in the array. By segmenting the spatial field and assigning different antennas to different angular sectors, the system achieves comprehensive coverage on both sides of the robot's path simultaneously, eliminating the sequential limitation of mechanical scanning while improving overall detection capability.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If conventional radar techniques are used, then simple implementation is achieved, but resolution and penetration depth deteriorate

Engineering Contradiction:
Improveimplementation simplicityVSAvoidresolution and penetration depth
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent creates a composite signal processing system that integrates multiple radar techniques: Doppler effect analysis for motion detection, phase difference measurement for angular positioning, and reprojection algorithms for accurate range calculation. This composite approach combines the advantages of different methods to achieve superior resolution and penetration depth while maintaining implementation feasibility through systematic signal processing.

Inventive Principle:
Principle #40Composite materials

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 mapping and obstacle avoidance in indoor environments, improving the radar sensor's resolution and penetration depth, and allowing for efficient path planning and navigation without the need for elaborate receiver arrays or mechanical scanning.

Implementation Method 1

calculate the angle of detection by analyzing Doppler effects and phase differences between antenna signals

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Implementation Method 2

calculate the angle of detection by analyzing Doppler effects and phase differences between antenna signals

Methodology Applied
Scientific EffectPhase difference:

Data Source

PatentUS11163059B2System and method for radar based mapping for autonomous robotic devices
Publication Date: 2021.11.02 BSH HOME APPLIANCES CORP
  • US11163059B2 patent drawing
  • US11163059B2 patent drawing
  • US11163059B2 patent drawing

AI summary

Data from a radar sensor moving through a static environment may be smoothed and used to generate range profiles by approximating peaks. A direction of arrival (DOA) can then be determined based on the range profile in order to generate a reprojection map. The reprojection map is used to provide updates to a stored map in a robot.