Legged Robot Coordinate Transformation for Observation Precision

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing robots face precision issues in expressing observation results due to errors caused by differences between command issuance and actual movement, particularly during dynamic changes in orientation, leading to inaccurate obstacle avoidance when combining observation results over time.

Innovation Solution

A robot apparatus with a main body, movable portions, reference coordinate systems at floor contact points, and calculating means to determine movement amounts between these systems, allowing precise expression of observation objects by correcting and transforming coordinates using kinematics and time information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the robot uses a robot center coordinate system to process observation results, then the robot can process observations with a unified reference frame, but errors accumulate due to the difference between command issuance time and actual movement time

Engineering Contradiction:

Improveobservation result precisionVSAvoidtime delay between command and execution

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent calculates and stores the movement amount of the robot center coordinate system in advance based on the movement command, before the actual movement occurs. This allows the observation results to be corrected using pre-calculated transformation data, eliminating the error caused by time delay between command issuance and actual movement execution.

Inventive Principle:

Principle #10Preliminary action

2Speed

If the robot swings through a large angle during walking, then the robot can move efficiently, but the observation result becomes indeterminate during the swinging motion

Engineering Contradiction:

Improvewalking speedVSAvoidobservation result determinability

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent pre-calculates the movement amount of the robot center coordinate system based on the movement command before the swinging motion occurs. By having the transformation data ready in advance, the system can accurately map observation results to the robot center coordinate system even during large-angle swinging motions, preventing the indetermination problem.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the robot combines observation results obtained at various times, then the robot can make more informed decisions, but errors from pace differences cause the robot to fail to avoid obstacles

Engineering Contradiction:

Improvedecision-making capabilityVSAvoidobservation result accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces a feedback mechanism where the calculated movement amount of the robot center coordinate system is used to correct observation results. By continuously updating the transformation based on actual movement commands and their executed movement amounts, the system compensates for errors accumulated from combining observations taken at different times, ensuring accurate obstacle avoidance decisions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS7437214B2Robot device and method of controlling the same

Publication Date: 2008.10.14 SONY GROUP CORP

AI summary

A legged mobile robot can calculate the movement amount between a portion of the robot apparatus that had been in contact with a floor up to now and a next portion of the robot apparatus in contact with the floor using kinematics and to switch transformation to a coordinate system serving as an observation reference as a result of the switching between the floor contact portions.