Robot Picking Control for Completing Conveyor Workpiece Groups

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Solution Overview

Problem

Existing robot systems face inefficiencies in workpiece transfer due to potential lack of combination on the second conveyor, leading to waiting and reduced transfer efficiency.

Innovation Solution

A robot system with a controller, situation acquirer, determiner, and instructor that identifies missing workpieces on the first conveyor and prioritizes their transfer to the second conveyor, ensuring complete workpiece groups are formed without decelerating or stopping the conveyors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If workpieces are picked from the first conveyor in the order they are conveyed, then the transfer process is simple, but there is a possibility of workpieces lacking in combination on the second conveyor, requiring the conveyor to decelerate or stop

Engineering Contradiction:
Improvetransfer process simplicityVSAvoidconveyor transfer efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The situation acquirer acquires information about workpieces in advance within a predetermined monitor area before they reach the robot's movable range. The determiner then identifies missing workpieces for combination based on this advance information, allowing the robot to prioritize picking missing workpieces before they fall behind the monitor area, thus preventing combination failures without stopping the conveyor.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the second conveyor decelerates or stops to wait for workpiece combination, then complete workpiece groups are ensured, but transfer time increases and efficiency decreases

Engineering Contradiction:
Improveworkpiece combination completenessVSAvoidconveyor waiting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The situation acquirer continuously monitors the types and positions of workpieces on both conveyors within the predetermined monitor area. The determiner uses this feedback information to identify which workpieces are missing from upcoming combinations. The instructor then directs the robot to prioritize picking these missing workpieces, creating a closed-loop control system that ensures complete workpiece groups without requiring conveyor stops.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the robot picks workpieces in conveyance order, then the picking process is straightforward, but workpiece combination may be incomplete requiring conveyor interruption

Engineering Contradiction:
Improvepicking process simplicityVSAvoidoverall transfer efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The instructor dynamically adjusts the robot's picking priority based on real-time situation information. When missing workpieces are detected in the monitor area, the robot prioritizes picking those specific workpieces over others, even if it means deviating from strict conveyance order. This dynamic adjustment ensures complete workpiece groups while maintaining high transfer efficiency without requiring conveyor interruptions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2998077B1Robot system, robot apparatus, and method for picking workpiece
Publication Date: 2021.03.10 YASKAWA DENKI KK
  • EP2998077B1 patent drawingFigure 1A~1B
  • EP2998077B1 patent drawingFigure 1C
  • EP2998077B1 patent drawingFigure 2

AI summary

A robot system includes a first conveyor, a second conveyor, a robot, and a controller. The first conveyor conveys a plurality of kinds of workpieces. The second conveyor conveys workpiece groups each including a combination of the workpieces. The controller controls the robot, and includes a situation acquirer, a determiner, and an instructor. The situation acquirer acquires a situation in a predetermined monitor area on the first and second conveyors. The monitor area is set based on a movable range of the robot. Based on the situation, the determiner determines whether one of the workpieces on the first conveyor in the monitor area is a missing workpiece of one of the workpiece groups in the monitor area. The instructor instructs the robot to hold the one workpiece and to transfer the one workpiece from the first conveyor to the second conveyor.