Robot Occupancy Mapping by Filtering Dynamic and Unfixed Objects

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Solution Overview

Problem

Mobile robots face challenges in constructing accurate occupancy maps due to objects that adversely affect map accuracy, such as dynamic and unfixed objects which are difficult to distinguish from static and fixed objects using conventional sensors.

Innovation Solution

A robot system that classifies objects into predefined permanency categories (fixed, static and unfixed, dynamic) using image analysis, excluding undesirable classifications to generate a more accurate occupancy map, with the ability to update classifications based on repeated observations and user-defined criteria.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional sensors are used to detect objects in the region, then the robot can detect objects present in the environment, but the robot cannot reliably distinguish between static/fixed objects and dynamic/unfixed objects, resulting in inaccurate occupancy maps

Engineering Contradiction:
Improveobject classification accuracyVSAvoidoccupancy map accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the occupancy map generation process into distinct phases: initial mapping phase where all detected objects are included, and operational phase where only static and fixed objects are retained. This segmentation allows the system to handle the contradiction by treating different object types differently at different stages of operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic object classification where objects are initially assumed to be part of the environment (static/fixed) and are reclassified as dynamic/unfixed when detected in multiple different locations during robot operations. This dynamic adaptation resolves the contradiction by allowing the system to maintain high measurement precision initially while ensuring reliability through continuous observation and reclassification.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the robot includes all detected objects in the occupancy map, then the map is comprehensive, but dynamic and unfixed objects adversely affect the accuracy and reliability of the map

Engineering Contradiction:
Improvenumber of objects in mapVSAvoidmap accuracy
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent extracts and removes dynamic and unfixed objects from the occupancy map after initial construction. During the operational phase, when objects are detected in multiple locations, they are identified as dynamic/unfixed and excluded from the final occupancy map, retaining only static and fixed objects. This extraction process maintains comprehensive initial mapping while ensuring final map reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements a feedback mechanism where the robot continuously monitors object positions during operations and uses this information to reclassify objects. Objects detected in multiple different locations provide feedback that they are dynamic/unfixed, triggering their exclusion from the occupancy map. This feedback loop ensures map accuracy while maintaining comprehensive object detection.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the robot traverses the region multiple times to improve map accuracy, then more objects can be classified correctly, but time is lost and productivity decreases

Engineering Contradiction:
Improveobject detection accuracyVSAvoidmapping efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary occupancy map construction during the initial robot traversal, including all detected objects in the map. This preliminary action ensures comprehensive coverage without requiring multiple traversals for basic map creation. Subsequent traversals are used only for object reclassification, significantly reducing the time penalty while maintaining high detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies partial action by focusing subsequent traversals specifically on object reclassification rather than complete remapping. Only objects detected in multiple locations are reevaluated and reclassified, while the rest of the map remains unchanged. This partial reprocessing approach maintains high measurement precision without the full time cost of complete remapping.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11562524B2Mobile robots to generate occupancy maps
Publication Date: 2023.01.24 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • US11562524B2 patent drawing
  • US11562524B2 patent drawing
  • US11562524B2 patent drawing

AI summary

An example control system includes a memory and at least one processor to obtain image data from a given region and perform image analysis on the image data to detect a set of objects in the given region. For each object of the set, the example control system may classify each object as being one of multiple predefined classifications of object permanency, including (i) a fixed classification, (ii) a static and fixed classification, and/or (iii) a dynamic classification. The control system may generate at least a first layer of a occupancy map for the given region that depicts each detected object that is of the static and fixed classification and excluding each detected object that is either of the static and unfixed classification or of the dynamic classification.