Automatic Mower Path Replanning Around Unknown Obstacles

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Solution Overview

Problem

Existing power machines, such as zero-turn mowers, face challenges in automatically navigating around unknown obstacles during mowing operations, as they rely on pre-defined paths that may not account for dynamic changes in the terrain or presence of unseen objects, leading to inefficiencies and potential damage.

Innovation Solution

Implementing an electronic controller system that uses sensor data to detect unknown objects and dynamically determine new work paths by decomposing the geographical area into cells, determining the shortest path between them, and adjusting the mowing trajectory to avoid obstacles, allowing the machine to continue mowing efficiently and safely.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a pre-defined work path is used for automatic mowing, then the mowing operation can be automated and performed without human intervention, but the system cannot adapt to unknown obstacles or dynamic changes in the terrain

Engineering Contradiction:
Improveautomatic mowing operationVSAvoidadaptability to unknown obstacles
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts the work path during mowing operations based on real-time sensor data. The electronic processor continuously receives sensor inputs, detects unknown objects, and modifies the planned path on-the-fly, transitioning from a static pre-defined path to a dynamic adaptive path that responds to environmental changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements a feedback loop where sensor data from the mowing area is continuously fed back to the electronic processor. This feedback mechanism allows the system to detect unknown objects and environmental changes, then adjust the work path accordingly, enabling the automated system to adapt to conditions not present in the original path planning.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the system continuously detects and reroutes around obstacles, then adaptability and safety improve, but computational complexity and processing requirements increase

Engineering Contradiction:
Improveability to detect and reroute around obstaclesVSAvoidcomputational complexity of path planning
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The geographical area is decomposed into discrete cells, and the path planning problem is segmented into finding the shortest path between these cells. This segmentation simplifies the computational complexity by breaking down the continuous path planning problem into discrete steps, making real-time obstacle avoidance more manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system determines the shortest path only for the remaining unmowed area after detecting an obstacle, rather than recalculating the entire path from scratch. This partial action approach reduces computational requirements by focusing only on the necessary portion of the path that needs adjustment.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If the mowing path is dynamically adjusted to avoid obstacles, then complete coverage of the mowing area can be maintained, but the time required to complete the mowing event may increase

Engineering Contradiction:
Improvecomplete coverage of mowing areaVSAvoidtime to complete mowing event
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system pre-decomposes the geographical area into cells and pre-calculates the shortest path between them before actual mowing begins. This preliminary action prepares the path structure in advance, enabling faster real-time adjustments when obstacles are detected, thereby reducing the time penalty associated with dynamic rerouting.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

When an obstacle is detected, the system recalculates the path only for the remaining unmowed area rather than the entire area. This partial recalculation minimizes the additional time required while still ensuring complete coverage of the remaining mowing area.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS20230333563A1Path planning for automatic mowers
Publication Date: 2023.10.19 CLARK EQUIPMENT CO
  • US20230333563A1 patent drawing
  • US20230333563A1 patent drawing
  • US20230333563A1 patent drawing

AI summary

Methods and systems are provided for controlling automatic travel of a power machine, including a mower, along a work path associated with a geographical area. As unknown objects are detected along a current work path, new work paths can be determined for a remaining portion of the geographical area (e.g., an area not yet mowed).