Robotic Work Tool Sensor Layout for Wider Obstacle Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing robotic lawn mowers and outdoor robotic work tools face challenges in achieving comprehensive and efficient obstacle detection, leading to potential collisions due to limited sensor coverage.

Innovation Solution

The implementation of an environmental detection system comprising a set of outer detector transceivers and a set of inner detector transceivers, where the inner transceivers are positioned between the outer transceivers, allowing for increased sensor coverage and improved collision avoidance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single sensor or limited number of sensors are used for obstacle detection, then the device complexity is reduced, but the sensor coverage and detection reliability are insufficient

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection system is segmented into multiple detector transceivers positioned at different locations (front, rear, left, right sides) of the robotic work tool. Each transceiver independently monitors obstacles in its specific direction, collectively providing comprehensive 360-degree coverage while maintaining manageable individual component complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection system transitions from single-point or limited-direction sensing to multi-dimensional spatial coverage by distributing detectors across multiple positions and orientations around the robotic work tool, creating a three-dimensional detection network that comprehensively monitors the environment

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

2Area of stationary object

If sensors are positioned to cover a wide area, then the sensor coverage is improved, but the detection precision and reliability for specific directions may be reduced

Engineering Contradiction:
Improvesensor coverage areaVSAvoiddetection precision
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The wide-area detection task is segmented into multiple directional detection zones, with each detector transceiver responsible for a specific sector. This segmentation allows each sensor to maintain high precision in its designated direction while collectively covering the entire surrounding area

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each detector transceiver is optimized for its specific local detection zone with appropriate positioning and orientation. The front detectors face forward for optimal forward obstacle detection, while side and rear detectors are positioned to maximize their respective directional coverage, ensuring high detection precision in each local area

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If multiple detector transceivers are used to increase coverage, then the detection coverage is improved, but the energy consumption increases

Engineering Contradiction:
Improvedetection coverageVSAvoidenergy consumption
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The detector transceivers operate in periodic cycles rather than continuously, alternating between active transmission/detection phases and low-power standby phases. This periodic operation maintains detection coverage while significantly reducing average energy consumption compared to continuous operation of all transceivers

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically activates only the detector transceivers needed for current operational conditions. For example, during forward movement, front detectors are activated while rear detectors may be in low-power mode, allowing the system to adapt energy consumption to actual detection requirements

Inventive Principle:
Principle #15Dynamics

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 configuration enhances the robotic work tool's ability to detect obstacles in time, preventing collisions by forming a combined rectangular coverage area in front of the tool, thereby increasing reliability and efficiency.

Implementation Method 1

Each detector transceiver is adapted to transmit signals and to receive reflected signals that have been reflected by an object

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP3909412B1An outdoor robotic work tool comprising an environmental detection system
Publication Date: 2025.04.02 HUSQVARNA AB
  • EP3909412B1 patent drawingFigure 1
  • EP3909412B1 patent drawingFigure 2
  • EP3909412B1 patent drawingFigure 3

AI summary

Outdoor robotic work tool (1) adapted for a forward travelling direction (D) and comprising an environmental detection system (19) that comprises a set of outer detector transceivers (2a, 2b) and a set of inner detector transceivers (3a, 3b), where the inner detector transceivers are positioned between the outer detector transceivers. Each detector transceiver is adapted to transmit signals (4a, 4b; 5a, 5b) and to receive reflected signals (6a, 6b, 9) that have been reflected by an object (10, 11). The outer detector transceivers are associated with outer coverage main directions (7a, 7b) that are directed at corresponding outer angles (αa, αb) to the forward travelling direction, and the inner detector transceivers are associated with inner coverage main directions (8a, 8b) that are directed at corresponding inner angles (βa, βb) to the forward travelling direction. The inner angles have magnitudes that exceed the magnitudes of the outer angles, and the inner coverage main directions intersect in front of the outdoor robotic work tool in the forward travelling direction.