Autonomous Lawnmower Slip Detection on Slopes

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Solution Overview

Problem

Autonomous working devices, such as lawnmowers, face challenges in accurately determining slip and inclination on slopes, which affects their driving behavior and efficiency, as existing technologies do not effectively account for these parameters in determining lateral speed and movement strategies.

Innovation Solution

The evaluation unit in the autonomous working device incorporates sensors and location-locating units to detect parameters such as slip, inclination, and lateral speed, using a Cartesian coordinate system to determine the device's position and adapt its driving strategy, particularly by accounting for axes perpendicular to the vertical axis, enabling precise control and efficient operation on slopes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the autonomous working device uses existing slip determination methods, then the device can operate autonomously, but the determination of slip and inclination on slopes is inaccurate, affecting driving behavior and efficiency

Engineering Contradiction:
Improveslip determination accuracyVSAvoiddriving efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent transitions from traditional two-dimensional slip measurement to three-dimensional measurement by incorporating inclination sensors that detect angles around multiple axes (roll, pitch, yaw). This dimensional expansion allows the evaluation unit to distinguish between lateral movement caused by slope inclination versus actual transverse movement, significantly improving slip determination accuracy on inclined surfaces while maintaining driving efficiency through more precise navigation control

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

2Adaptability or versatility

If the device determines lateral speed without considering inclination, then the navigation is simpler, but the driving behavior cannot be optimized for slope conditions

Engineering Contradiction:
Improveadaptation to slope conditionsVSAvoidnavigation system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The evaluation unit is designed as a multi-functional system that simultaneously processes data from sensors for multiple purposes: determining slip, calculating inclination angles around different axes, computing lateral speed, and optimizing driving behavior. This universal approach allows the same hardware infrastructure to handle both simple flat-surface operation and complex slope adaptation, achieving versatility without proportionally increasing device complexity

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

Solution Approach 2:

The patent introduces an intermediary evaluation unit that acts as a mediator between raw sensor data and driving control. This evaluation unit processes inclination measurements from sensors and transforms them into corrected lateral speed calculations, enabling the navigation system to adapt to slope conditions without requiring complete redesign of the navigation architecture. The intermediary layer simplifies the integration of complex slope compensation functionality

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the device uses complex landmarks for navigation, then navigation accuracy is improved, but the device requires more complex infrastructure and increases operational complexity

Engineering Contradiction:
Improveposition determination accuracyVSAvoidnavigation infrastructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The autonomous working device uses its own motion sensors and inclination detectors to self-determine its position and orientation on slopes without relying on external landmark infrastructure. The evaluation unit processes data from the device's own sensors (accelerometers, gyroscopes, wheel encoders) to calculate lateral speed and correct for slope effects, enabling the device to navigate accurately on slopes using self-contained sensing capabilities rather than complex external landmark systems

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2802950B1Autonomous working device
Publication Date: 2017.05.10 ROBERT BOSCH GMBH
  • EP2802950B1 patent drawingFigure 1
  • EP2802950B1 patent drawingFigure 2~3

AI summary

The invention is based on an autonomous implement, in particular of an autonomous lawnmower, having at least one drive unit (12) which has at least one driven wheel (14, 16), having at least one sensor unit (18), having at least one location-determining unit (20) and having at least one evaluation unit (22). It is proposed that the evaluation unit (22) be provided for taking into account, in order to determine slip of the at least one driven wheel (14, 16), at least one characteristic variable (24, 28, 32) which is sensed by the sensor unit (18), and at least one characteristic variable (26) which is sensed by the location-determining unit (20).