Manipulator Tracking Control With Dual Imaging for Moving Workpieces

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Solution Overview

Problem

Conventional manipulator systems struggle to accurately perform tasks on workpieces moving on conveyors or other devices due to inadequate detection of workpiece position and movement.

Innovation Solution

A manipulator system that includes a robotic arm, an operating device, imaging means, and a control device, which detects the moving amount of the workpiece based on the driving amount of the conveyor or positioner, allowing for accurate tracking and control of the robotic arm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If synchronous instruction value is calculated based on present coordinates of slave arm hand part and speed setting value of conveyor, then the control system can operate the robotic arm, but the position of the workpiece on the conveyor cannot be accurately detected

Engineering Contradiction:
Improveworkpiece position detection accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical calculation method (based on arm coordinates and conveyor speed) with an optical detection system (imaging means/camera) to directly measure workpiece position. The imaging means captures images of the workpiece on the conveyor, and the control device calculates actual position from these images, providing accurate detection without complex mechanical sensing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If the robotic arm tracks the moving workpiece, then the work accuracy improves, but the worker has difficulty operating the tool due to the moving image

Engineering Contradiction:
Improvework accuracyVSAvoidoperator control difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent divides the imaging function into two separate systems: a first imaging means (tracking camera) attached to the robotic arm that moves with the workpiece to maintain accurate positioning, and a second imaging means (fixed camera) that remains stationary to provide a stable overview image for the operator. This segmentation allows each imaging system to fulfill its specific function without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device acts as an intermediary that processes images from both imaging means and generates composite display information. It combines the tracking image data with the fixed overview image, allowing the operator to see both the stable reference frame and the accurate work position simultaneously through the display device.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a single fixed camera is used to monitor the work area, then the system structure is simple, but the workpiece cannot be continuously tracked throughout its movement

Engineering Contradiction:
Improvecontinuous workpiece trackingVSAvoidimaging system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the first imaging means dynamic by attaching it to the robotic arm, allowing it to move together with the arm and continuously track the workpiece throughout the work area. This dynamic positioning ensures the workpiece remains within the imaging range regardless of its position on the conveyor or the arm's movement, providing reliable continuous tracking.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3342550B1Manipulator system
Publication Date: 2025.05.07 KAWASAKI JUKOGYO KK
  • EP3342550B1 patent drawingFigure 1
  • EP3342550B1 patent drawingFigure 2
  • EP3342550B1 patent drawingFigure 3~4

AI summary

A manipulator system configured to perform a work to a workpiece being moved by a moving device, includes a robotic arm, having one or more joints and to which a tool configured to perform the work to the workpiece is attached, an operating device configured to operate the robotic arm, a first imaging means configured to image the workpiece, while following the movement of the workpiece, a second imaging means fixedly provided in a work area to image a situation of the work to the workpiece, a displaying means configured to display an image imaged by the first imaging means and an image imaged by the second imaging means, and a control device configured to control the operation of the robotic arm based on an operating instruction of the operating device, while detecting a moving amount of the workpiece being moved by the moving device and carrying out a tracking control of the robotic arm according to the moving amount of the workpiece.