Radar Obstacle Detection in Autonomous Lawn Mower Robots

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing lawn mower robots face challenges with obstacle detection due to sensitivity to light variations and environmental conditions, requiring frequent maintenance of video cameras and multiple infrared sensors.

Innovation Solution

A lawn mower robot equipped with a radar sensor system that uses electromagnetic signals to detect objects, calculate distances, and adjust movement and cutting operations, providing robustness against environmental changes and reducing the need for complex perimeter installations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If video cameras are used for detecting objects, then object detection capability is provided, but the system becomes sensitive to light variations and requires continuous maintenance

Engineering Contradiction:
Improveobject detection capabilityVSAvoidsensitivity to light variations and maintenance requirements
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The patent replaces optical detection systems (video cameras) with electromagnetic radiation-based detection (radar sensors). This substitution eliminates sensitivity to visible light conditions and reduces maintenance requirements since radar sensors are not affected by mud or dirt accumulation in the same way optical sensors are.

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

Solution Approach 2:

The invention changes the detection parameter from optical wavelength (video camera) to electromagnetic wavelength in the radar frequency range. This parameter change fundamentally alters the interaction with environmental factors, making detection independent of light conditions and less susceptible to contamination.

Inventive Principle:
Principle #35Parameter changes

2Difficulty of detecting and measuring

If infrared sensors are used for object detection, then detection capability is improved, but multiple sensors are required and continuous maintenance is needed

Engineering Contradiction:
Improveobject detection capabilityVSAvoidnumber of sensors and maintenance requirements
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent replaces infrared sensor arrays with a radar-based electromagnetic detection system. This substitution reduces the number of individual sensing elements required while maintaining or improving detection capability, and eliminates the maintenance issues associated with keeping multiple infrared sensors clean and functional.

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

Solution Approach 2:

The radar sensor system performs multiple functions (detection, ranging, obstacle identification) with a single integrated system, whereas infrared solutions require multiple specialized sensors. This multi-functionality reduces overall system complexity and maintenance burden.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If perimeter wire is installed to delimit work area and detect obstacles, then robot containment and obstacle avoidance are achieved, but installation complexity and precision requirements increase

Engineering Contradiction:
Improverobot containment and obstacle avoidanceVSAvoidperimeter wire installation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical perimeter wire system with electromagnetic radiation-based detection. The radar sensor actively emits and receives electromagnetic signals to detect obstacles and define the work area, eliminating the need for physical wire installation while maintaining reliable containment and obstacle avoidance.

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

Solution Approach 2:

The radar-based system provides self-contained obstacle detection and area definition capabilities within the robot itself, eliminating the need for external perimeter infrastructure. The robot independently detects and adapts to its environment without requiring pre-installed guidance wires or physical barriers.

Inventive Principle:
Principle #25Self-service

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

Enables safe and efficient autonomous movement within a work area, accurately detecting obstacles and adapting to their presence without requiring continuous maintenance or complex setup, ensuring reliable operation across varying light conditions.

Implementation Method 1

detection system (14) comprising a radar sensor (140) configured for transmitting a first electromagnetic signal (S1) and for receiving a second electromagnetic signal (S2)

Methodology Applied
Scientific EffectElectromagnetic radiation transmission and reflection: Radar

Implementation Method 2

the first signal S1 reflected at the object O and the second electromagnetic signal S2 may comprise an echo of the first signal S1 reflected

Methodology Applied
Scientific EffectSignal reflection: Reflection

Implementation Method 3

calculating a distance between the lawn mower robot (1) and the object (O) detected as a function of the first and second signals (S1, S2)

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3794921B1Lawn mower robot and corresponding process
Publication Date: 2023.12.06 BERNINI FAB
  • EP3794921B1 patent drawingFigure 1~3
  • EP3794921B1 patent drawingFigure 4~6
  • EP3794921B1 patent drawingFigure 7~8

AI summary

Described is a lawn mower robot (1) comprising: - grass cutting means (10) for performing an operation for cutting grass in a working area (A), - movement means (12) configured for moving substantially autonomously the lawn mower robot (1) along a feed direction (X) inside said working area (A), - a detection system (14) configured for detecting the presence of at least one object (O) in a detection zone (C) in front of the lawn mower robot (1). The detection system (14) comprises: - a radar sensor (140) configured for transmitting a first electromagnetic signal (S1) and for receiving a second electromagnetic signal (S2), and - a processing module (142), coupled to the radar sensor (140) and configured to receive from the radar sensor (140) the first (S1) and the second (S2) signal, and to detect a presence of an object (O) checking whether the second signal (S2) comprises said first signal (S1).