Computer Vision Cycle Time Measurement for Assembly Lines

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Solution Overview

Problem

Traditional manual methods for measuring cycle time in manufacturing assembly lines are inefficient for long-term and continuous monitoring, leading to inaccurate productivity statistics.

Innovation Solution

A computer-based method and apparatus that identifies start and end actions in image frames to determine cycle time by detecting hand movements, using imputation to fill gaps in missing data and averaging ground truths for accurate cycle time estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual measurement using stop-watch is used, then measurement simplicity is maintained, but measurement precision and continuity deteriorate

Engineering Contradiction:
Improvemeasurement simplicityVSAvoidcycle time measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the manual mechanical stop-watch system with an automated computer vision system. The system uses cameras to capture images of workers performing tasks, processes these images through computer algorithms to automatically detect task completion, and records cycle times without human intervention. This substitution eliminates the limitations of manual sampling while maintaining operational simplicity through automation.

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

Solution Approach 2:

The system enables self-service measurement where the workers themselves are the subject of measurement without requiring manual observation. The automated system continuously monitors and measures cycle times as workers naturally perform their tasks, eliminating the need for separate manual measurement operations and ensuring continuous, unbiased data collection.

Inventive Principle:
Principle #25Self-service

2Device complexity

If manual sampling measurement is used, then device complexity is reduced, but reliability of long-term monitoring deteriorates

Engineering Contradiction:
Improvemeasurement system simplicityVSAvoidcontinuous monitoring reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements continuous monitoring by having the camera system operate throughout the entire work shift without interruption. The system continuously captures images, processes them in real-time, and maintains an ongoing record of cycle times. This continuous action eliminates the reliability issues associated with periodic sampling while the automated nature of the system keeps complexity manageable through standardized algorithms.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces a computer processing system as an intermediary between the camera and the measurement output. This intermediary automatically analyzes images, identifies task completion events, and calculates cycle times, thereby bridging the gap between simple data collection and reliable measurement. The intermediary handles the complexity of continuous processing while maintaining measurement reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If video analytics is used instead of manual measurement, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvecycle time estimation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex video analytics system into distinct functional modules: image capture, image processing, task detection, and cycle time calculation. Each module handles a specific aspect of the measurement process independently, making the overall complex system more manageable and easier to implement. This segmentation allows the system to achieve high measurement precision through specialized processing while keeping device complexity organized and controllable.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS20240086812A1A method, an apparatus and a non-transitory computer readable medium for measuring productivity
Publication Date: 2024.03.14 NEC CORP
  • US20240086812A1 patent drawing
  • US20240086812A1 patent drawing
  • US20240086812A1 patent drawing

AI summary

A method, an apparatus (70) and a program(s) for measuring productivity are provided. The method comprises: identifying a first movement based on at least one image frame, wherein the first movement matches a start action which define a cycle of movements (S1); identifying a second movement based on at least one image frame, wherein the second movement matches an end action which define the cycle (S2); and determining a period of time between the identified first movement and the identified second movement to measure productivity (S3).