Direct part identification

How can plant engineers ensure that a part is easily identified by machine vision systems? Justin Testa, senior vice president of ID Products for Cognex Corp., suggests these considerations:

12/01/2006


How can plant engineers ensure that a part is easily identified by machine vision systems? Justin Testa, senior vice president of ID Products for Cognex Corp., suggests these considerations:

  • Code selection %%MDASSML%% The ANSI code standard is the most widely supported for DPMI applications involving metal, glass, ceramic or plastic materials. Data Matrix offers a number of advantages for DPMI applications, including small size, high data encoding capacity and error correction that allows a code to be successfully read even though as much as 60% of the code may be damaged.

  • Available space %%MDASSML%% Limited space may require the Data Matrix code be used as a 'license plate’ to simply identify the part, reducing the amount of data encoded. In this case, a centralized database containing manufacturing and historical data on the device is updated as it is identified during manufacturing and supply chain processes. When space isn’t an issue, users may encode much more information about the part, creating a 'portable database.’

  • Marking processes %%MDASSML%% The primary methods for producing machine-readable symbols for DPM ID include: dot peening, laser marking, electro-chemical etching and ink-jet printing. Your choice depends on part life expectancy, material composition, environmental wear and tear and production volume. Other considerations include: surface texture, amount of data to be encoded, and the available space and location of the mark.

  • Mark placement %%MDASSML%% The location should be clearly visible throughout the manufacturing process; it’s best to mark on a flat site. Choose a location where the mark is in a prominent position easily viewed by the reader. Avoid locations where a surrounding surface relief could potentially affect the illumination of the code by the reader’s lighting source. Provide a 'clear zone’ around the mark where no features, part edges, surface texture or other interferences come into contact with the code. If a mark must be placed on a cylindrical part, take care in selecting the size of the code. Curved surfaces can create distortions to the code and adversely affect illumination.

  • Readability %%MDASSML%% Features that comprise the Data Matrix symbol are the quiet zone, the finder pattern, the clocking pattern and the data region. Each individual element is referred to as a module. Robust and reliable code reading requires a pattern with individual modules consistent in shape and size with each other, and distinctively different in shape and size from other features on the part’s surface.

  • Verification %%MDASSML%% A verification system can immediately detect a mark-process problem, which could be due to poor part fixturing; damage to the machine, such as a broken tip on a dot peen machine; or incorrect settings during part changeover. Additionally, a code verification system can also provide a process feedback on the marking process that can be used in preventive maintenance. For example, the verifier can monitor tip wear on a dot peen machine by monitoring dot size and flag the operator on the floor when a pin should be changed.



    The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
    The Product of the Year program recognizes products newly released in the manufacturing industries.
    Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
    Doubling down on digital manufacturing; Data driving predictive maintenance; Electric motors and generators; Rewarding operational improvement
    2017 Lubrication Guide; Software tools; Microgrids and energy strategies; Use robots effectively
    Prescriptive maintenance; Hannover Messe 2017 recap; Reduce welding errors
    The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
    Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
    Mobility as the means to offshore innovation; Preventing another Deepwater Horizon; ROVs as subsea robots; SCADA and the radio spectrum
    Research team developing Tesla coil designs; Implementing wireless process sensing
    Commissioning electrical systems; Designing emergency and standby generator systems; Paralleling switchgear generator systems
    Natural gas engines; New applications for fuel cells; Large engines become more efficient; Extending boiler life

    Annual Salary Survey

    Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

    There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

    But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

    Read more: 2015 Salary Survey

    Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
    The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
    The Society for Maintenance and Reliability Professionals an organization devoted...
    Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
    IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
    Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
    The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
    The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
    Featured articles highlight technologies that enable the Industrial Internet of Things, IIoT-related products and strategies to get data more easily to the user.
    This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
    Maintenance Manager; California Oils Corp.
    Associate, Electrical Engineering; Wood Harbinger
    Control Systems Engineer; Robert Bosch Corp.
    This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
    This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
    This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
    click me