Plasma Cutting Robot Arc Start Height Control for Shorter Takt Time

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Solution Overview

Problem

Existing plasma cutting robot control devices require the torch to move to the cutting height first and then to the pierce height, resulting in a longer takt time.

Innovation Solution

A robot control device with a teaching-playback type system that interprets a teaching program to set the arc start height of the torch based on position information from a move instruction, allowing for appropriate movement of the plasma cutting robot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the torch moves to the cutting height first and then to the pierce height using the cutting height as a reference, then the plasma cutting operation can be performed, but the takt time becomes long

Engineering Contradiction:
Improveplasma cutting operationVSAvoidtakt time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by setting the arc start height using position information from the move instruction generated after the plasma cutting start instruction. This allows the torch to move directly to the correct arc start height without first moving to the cutting height as an intermediate step, thereby eliminating unnecessary movement and reducing takt time while ensuring reliable plasma cutting operation

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If only the path to the cutting height is taught in the teaching program, then the plasma cutting robot can be controlled, but the torch has to move to the cutting height first and then to the pierce height, resulting in longer operation time

Engineering Contradiction:
Improveteaching program controlVSAvoidoperation time
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying how the arc start height is determined. Instead of using a fixed reference to the cutting height, the system uses the position information from the subsequent move instruction to set the arc start height. This parameter change allows the teaching program to remain simple while enabling direct movement to the correct height, thus improving productivity without compromising ease of operation

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach shortens the takt time by enabling the plasma cutting robot to move more efficiently to the arc start height, while also allowing for a common arc start condition to be used in the teaching program.

Implementation Method 1

the torch is moved to a pierce height and generates, with the work, an arc discharge with the work, whereby a pierce hole is penetrated

Methodology Applied
Scientific EffectArc discharge: Electric Arc

Data Source

PatentEP4513287A1Robot control device and plasma cutting method
Publication Date: 2025.02.26 DAIHEN CORP
  • EP4513287A1 patent drawingFigure 1
  • EP4513287A1 patent drawingFigure 2
  • EP4513287A1 patent drawingFigure 3

AI summary

Provided is a robot control device and a plasma cutting method that can shorten a takt time using a teaching program that appropriately moves a plasma cutting robot. The robot control device includes: a program reading unit that reads a teaching program to operate the plasma cutting robot; a program interpreting unit that interprets the teaching program which has been read; and a program executing unit that executes the teaching program that has been interpreted. In a case where the program interpreting unit interpreted an arc start instruction for plasma cutting in the teaching program, the program interpreting unit sets an arc start height of a torch in the plasma cutting robot included in the arc start instruction, using position information of the plasma cutting robot included in a move instruction generated after the arc start instruction.