Robot Calibration Device for Mechanism Error Parameter Adjustment

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Solution Overview

Problem

Robot systems face challenges in maintaining accurate position and orientation due to production errors and component wear, leading to difficulties in recalibrating after component replacement or robot installation errors, which reduces productivity and increases the risk of interference with peripheral devices.

Innovation Solution

A calibration apparatus and determination apparatus that acquire and calculate mechanism error parameters to adjust robot control, allowing for precise alignment of the robot's position and orientation by setting a reference coordinate system and using a three-dimensional measuring device to determine the need for recalibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If robot components are replaced to maintain operation, then robot reliability is improved, but manufacturing precision deteriorates due to inability to match pre-replacement position accuracy

Engineering Contradiction:

Improverobot operation reliabilityVSAvoidposition accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the parameters of the base coordinate system (position and orientation) to match the pre-replacement accuracy. By measuring the actual position and orientation of the base coordinate system after component replacement and calculating transformation parameters, the system adjusts these parameters to restore the robot's position accuracy without requiring re-teaching of operation programs.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If robot teaching work is performed to correct position after replacement, then position accuracy is improved, but productivity deteriorates due to time-consuming re-teaching

Engineering Contradiction:

Improveposition accuracyVSAvoidrecalibration efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical re-teaching process with an automated measurement and calculation system. Instead of manually re-teaching the robot's position and orientation through operation programs, the system uses a measuring device to automatically measure the base coordinate system and calculates transformation parameters, substituting time-consuming manual teaching with efficient automated computation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs preliminary measurement of the base coordinate system's position and orientation immediately after component replacement. By measuring and calculating the transformation parameters before resuming normal operation, the system prepares the corrected coordinate system in advance, allowing operation programs to be executed without interruption or re-teaching.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If operation program teaching position is corrected to maintain accuracy, then manufacturing precision is improved, but loss of time increases due to correction work for each operation program

Engineering Contradiction:

Improvedriving accuracyVSAvoidteaching work time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent creates a universal transformation parameter that applies to all operation programs simultaneously. Instead of correcting teaching positions in each individual operation program, the calculated transformation parameters are applied universally to the entire coordinate system, allowing all operation programs to maintain accuracy without individual corrections.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Manufacturing precision

If robot base coordinate system is restored to match pre-replacement position, then manufacturing precision is improved, but device complexity increases due to calibration requirements

Engineering Contradiction:

Improvebase coordinate system accuracyVSAvoidcalibration system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a measuring device as an intermediary between the robot's base coordinate system and the control system. This intermediary automatically measures the position and orientation of the base coordinate system and provides data for calculating transformation parameters, simplifying the calibration process while maintaining high accuracy without requiring complex manual calibration procedures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20240375284A1Calibration device for calibrating mechanism error parameter and determination device for determining necessity of calibrating mechanism error parameter

Publication Date: 2024.11.14 FANUC LTD

AI summary

This calibration device comprises a position acquisition unit for acquiring the position of a robot in a reference coordinate system, and a parameter calculation unit for calculating a mechanism error parameter. A first state of the robot and a second state of the robot later than the first state are defined. The parameter calculation unit calculates the mechanism error parameter such that, when the robot is driven by a command value of a movement program, the position of the robot in the reference coordinate system at the time of the second state matches with the position of the robot in the reference coordinate system at the time of the first state.