Robot-Mounted Measurement Path Planning for Occluded Workpiece Picking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Robotic systems face challenges in accurately recognizing and picking up workpieces with complex shapes or mirror surfaces due to occlusion and interreflection, leading to incomplete measurement data and inefficient object manipulation.

Innovation Solution

A control apparatus and method for a robotic system that includes a pose generator, measurement path determiner, and recognizer, which dynamically adjusts the measurement device's poses and path to ensure comprehensive coverage of the measurement area, allowing for reliable recognition and efficient object manipulation by generating poses based on geometric relationships and previous measurement data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measurement device uses a fixed field of view to measure objects, then the measurement process is simple and fast, but measurement data becomes incomplete when objects are occluded or have mirror surfaces

Engineering Contradiction:
Improvecompleteness of measurement dataVSAvoidcomplexity of measurement path planning
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the measurement device movable rather than fixed. The measurement device is mounted on the robotic arm and can dynamically adjust its position and orientation to capture objects from multiple angles, ensuring complete measurement data even when objects are occluded or have mirror surfaces.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent transitions from a single fixed viewpoint to multi-dimensional measurement by moving the measurement device along predetermined paths in three-dimensional space. This allows the system to capture objects from multiple perspectives, resolving the issue of incomplete data from occlusion or mirror surfaces.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the system performs 3D measurement and recognition for every object in the container, then object recognition accuracy improves, but processing time increases and throughput decreases

Engineering Contradiction:
Improveobject recognition accuracyVSAvoidwork efficiency for manipulating objects
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-determining measurement paths and poses before actual measurement. The system plans the measurement sequence in advance, allowing the robotic arm to efficiently traverse predetermined paths without real-time decision-making delays, thus maintaining high accuracy while improving throughput.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent ensures continuous useful action by integrating measurement operations into the robotic arm's existing movement cycles. The measurement device captures data during the arm's natural traversal of the container, eliminating separate measurement steps and maintaining continuous productivity while ensuring complete object recognition.

Inventive Principle:
Principle #20Continuity of useful action

3Speed

If the measurement device captures all objects in the container simultaneously, then measurement speed is high, but measurement data becomes incomplete due to occlusion

Engineering Contradiction:
Improvemeasurement speedVSAvoidcompleteness of measurement data
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the measurement process into multiple sequential captures from different poses rather than attempting a single comprehensive capture. The measurement device takes pictures at multiple predetermined positions and orientations, combining the data to achieve complete object recognition while maintaining efficient measurement speed.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4094904B1Robot system control device, robot system control method, computer control program, and robot system
Publication Date: 2024.05.15 OMRON CORP
  • EP4094904B1 patent drawingFigure 1A~1B
  • EP4094904B1 patent drawingFigure 2
  • EP4094904B1 patent drawingFigure 3

AI summary

A control apparatus for a robotic system including a robot and a measurement device located on a robotic arm of the robot causes less interruption in, for example, picking up objects such as workpieces from a container. The control apparatus generates poses of the measurement device to measure an object, determines, for the measurement device, a measurement path including the poses to cause the measurement device to move along the measurement path including the poses and to measure the object, instructs the robot to move the measurement device along a movement path including the measurement path and instructs the measurement device to measure the object in the poses, recognizes the object using obtained measurement data, and determines the measurement path for the measurement device for a next operating cycle.