Domestic Robot Occupancy Grid Updates for Temporary Obstacles

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Solution Overview

Problem

Existing household robots face challenges in continuously updating their occupancy grids to reflect changing environments, particularly temporary obstacles, which affects their mobility and navigation efficiency.

Innovation Solution

The use of a processing device that incorporates logit values from scanning and external sources to update the occupancy grid, allowing for efficient integration of new information and cooperation between robots to share and combine occupancy grid data, ensuring up-to-date navigation maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the occupancy grid is updated frequently to reflect changing environments and temporary obstacles, then the robot's navigation accuracy and obstacle avoidance improve, but the computational load and processing time increase

Engineering Contradiction:
Improvenavigation accuracyVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent transforms occupancy probabilities into logit values using a mathematical transformation. This parameter change allows the system to represent uncertainty in a way that facilitates efficient updating through simple addition operations rather than complex probability calculations, thereby maintaining high navigation accuracy while reducing computational processing time

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The occupancy grid is divided into discrete cells, each with its own logit value representing occupancy probability. This segmentation allows the robot to update only specific cells when new sensor data is received, rather than processing the entire grid, thus improving navigation accuracy for changed areas while minimizing overall processing time

Inventive Principle:
Principle #1Segmentation

2Loss of information

If the robot integrates occupancy information from multiple sources and multiple robots, then the completeness and accuracy of the occupancy grid improve, but the complexity of data integration and processing increases

Engineering Contradiction:
Improveoccupancy information completenessVSAvoiddata integration complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent combines occupancy information from multiple sensors and multiple robots by summing their respective logit values for corresponding cells. This merging approach allows the system to integrate diverse information sources efficiently, achieving complete and accurate occupancy maps while keeping the integration process computationally simple through additive operations

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The logit value serves as an intermediary representation that mediates between different information sources. By converting all occupancy probabilities to logit values before integration, the system creates a common framework that simplifies the combination of data from multiple robots and sensors, reducing integration complexity while maintaining information completeness

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the robot uses a detailed occupancy grid with many cells to represent the household environment, then the precision of obstacle detection and navigation improves, but the memory requirements and processing overhead increase

Engineering Contradiction:
Improveobstacle detection precisionVSAvoidmemory storage
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent uses logit values to parameterize occupancy probabilities, allowing the system to represent detailed environmental information in a compact numerical form. This parameter transformation enables high obstacle detection precision through fine-grained cell-level representation while reducing memory requirements compared to storing full probability distributions or raw sensor data for each cell

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4075230B1Card update for a domestic robot
Publication Date: 2024.05.08 BSH HAUSGERATE GMBH
  • EP4075230B1 patent drawingFigure 1
  • EP4075230B1 patent drawingFigure 2
  • EP4075230B1 patent drawingFigure 3

AI summary

An autonomously moving robot for a household comprises a sensor for scanning the household in the robot's environment; a processing device for determining an occupancy grid based on the scanning; wherein the occupancy grid comprises a plurality of cells, each cell representing a section of the household, and wherein the logit of occupancy by an object is specified for the cell; wherein the logit is the natural logarithm of the probability that the cell is occupied by an object; wherein the probability comprises the probability of occupancy divided by the probability of the cell not being occupied; wherein the processing device is configured to control the robot's movement within the household such that a section whose associated cell has a logit exceeding a predetermined threshold is not entered.