Autonomous Lawn Mower Docking Alignment Using Offset Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Autonomous working devices, such as lawn mowers, face challenges in accurately and independently navigating and docking with a base station for charging, especially due to inaccuracies in inertial navigation and the need for precise alignment with the charging interface.

Innovation Solution

The implementation of an orientation device with a path detection unit and direction detection unit, along with a control and regulating unit, allows for connectionless guidance and precise alignment with the base station, using a transmitting and receiving unit for communication and distance measurement to determine an offset relative to the base station's main axis, enabling targeted docking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If inertial navigation is used for autonomous guidance, then the device can operate independently without external guidance systems, but navigation accuracy deteriorates over distance due to cumulative errors

Engineering Contradiction:
Improveautonomous navigation capabilityVSAvoidposition accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent introduces a base station as an intermediary reference point that the autonomous device uses to correct its position and orientation. The device determines its offset relative to the base station's main axis using detection units, allowing it to recalibrate inertial navigation errors by referencing the known position of the base station during docking operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If precise alignment with the base station charging interface is required, then docking accuracy is improved, but the complexity of the orientation and docking system increases

Engineering Contradiction:
Improvedocking alignment precisionVSAvoidorientation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical alignment systems with optical or electromagnetic detection units that measure the offset relative to the base station's main axis. The control unit then calculates the necessary orientation adjustments, substituting mechanical complexity with computational geometry and sensor-based detection.

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

Solution Approach 2:

The patent introduces a new dimension of measurement by determining the offset relative to the base station's main axis rather than using traditional x-y coordinate alignment. This dimensional approach simplifies the docking problem by reducing it to a single offset parameter that can be measured and corrected more easily.

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

3Ease of operation

If connectionless guidance is used to simplify operation, then ease of operation is improved, but reliability of guidance deteriorates due to lack of continuous feedback

Engineering Contradiction:
Improveguidance system simplicityVSAvoidguidance accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The autonomous device performs self-guidance using its own detection units to determine its offset relative to the base station. The system is self-sufficient, requiring no continuous external guidance or feedback, yet maintains reliability by using multiple detection units and computational geometry to accurately determine position and orientation independently.

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

This solution ensures reliable and precise guidance of the autonomous device to the charging interface, maintaining high autonomy and operator comfort with improved accuracy and simplicity in operation.

Implementation Method 1

a transmitting and receiving unit for communication and distance measurement to determine an offset relative to the base station's main axis

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP3160319B1Autonomous work device
Publication Date: 2020.04.15 ROBERT BOSCH GMBH
  • EP3160319B1 patent drawingFigure 1
  • EP3160319B1 patent drawingFigure 2
  • EP3160319B1 patent drawingFigure 3

AI summary

The invention relates to an autonomous work device (10), in particular an autonomous lawnmower, comprising at least one orientation device (12), which is different from a delimiting-wire orientation device and which is provided for an orientation within a region (14) to be worked, and comprising at least one control and/or regulating unit (72) for ascertaining a travel strategy. The at least one control and/or regulating unit (72) is provided at least for ascertaining an alignment relative to a base station (18) for a controlled docking with an interface, in particular a charging interface (30), of the base station (18) dependent on at least one orientation variable detected by means of the at least one orientation device (12).