Machine vision tops sensors in flexibility for Ford body panel selection

02/06/2014


Vision without code writing

Cognex In-Sight vision systems include preconfigured drivers, ready-to-use templates, and sample code to accelerate system. Flexible Cognex EasyBuilder user environment allows setup of most inspection applications graphically without code writing. WorkingA flexible user environment makes it possible to set up virtually any inspection application graphically without writing a line of code. Working from an image of the part, the user begins by finding the vision system on the network and is guided through triggering the vision system and setting up the scale and nonlinear calibrations. The user can select from a library of vision tools to inspect the part. The user selects the data to be sent and the protocol for communicating with a PLC, robot, or human machine interface (HMI) for data collection and archiving. In the deployment mode, tool graphics, a results table, and a filmstrip control are available for validating and troubleshooting the application. The cameras are contained in a 75 mm by 55 mm by 47 mm IP67 package designed to survive in the factory environment.

In current applications, the camera is stationary and the robot moves the part into position for inspection. Future applications also will use the robot to move the vision system into position to inspect stationary body panels. The number and orientation of the studs determines how many cameras are required to inspect all of the studs. Current applications include the cowl and dashboard assembly and the left and right wheel housings. There are 15 to 17 studs on variants of the cowl and dash assembly and 10 to 12 studs on variants of the wheelhouse. Each of these panels is inspected with two vision systems.

The vision systems are programmable so they can accommodate new models and design changes with a simple program change.

The camera connects to either the robot or the PLC using the EtherNet/IP protocol. The PLC or robot tells the camera which model is being inspected and which program to use. The robot positions the part in front of the camera or cameras and the robot or PLC sends a signal to the camera or cameras to acquire an image. The camera inspects the part and based on the program determines whether the part passes or fails the inspection. The camera then sends a signal to the robot or PLC. If the part fails the inspection, then the PLC signals an operator to replace the bad panel.

Integrator develops application

Each application is implemented by a vision integrator who makes the decision on the best lighting and vision tools for the application. Two approaches have been used to date. One is based on the blob tool, which recognizes an object based on its shape. The second, based on the histogram tool, compares the graphical representation of the tonal distribution of the digital image to the saved representation of a good part. The vision systems also are used to read a 2D barcode on the body. The barcode is passed to another system that checks to ensure there are no open issues with the vehicle before it is released from the body shop.

“The initial cost of purchasing and setting up a vision system is higher than a dozen proximity sensors,” Vallade said. “However, proximity sensors generate downstream expenses, such as the cost of replacement sensors and the labor and downtime required for maintenance. We also need to consider the extra work required to prepare for a design change for new variants as well as the changeover that may be required when switching from one variant to another. By switching to machine vision we have substantially reduced the downstream costs by installing a noncontact inspection system that will last for many years without requiring any significant maintenance. The vision systems are programmable so they can accommodate new models and design changes with a simple program change. The bottom line is that machine vision will substantially reduce our overall inspection costs.”

- By John Lewis, market development manager, Cognex Corp. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering, mhoske(at)cfemedia.com

ONLINE

See related links below for machine vision and automotive manufacturing.

www.controleng.com/machinevision

www.cognex.com 

Key concepts

  • Ford improved flexibility by switching from sensors to machine vision for body panel inspection.
  • Noncontact machine vision inspection system avoids proximity sensor maintenance, reducing overall inspection costs.
  • Vision systems accommodate new models and design changes with a simple program change.

Consider this

Do you look at lifecycle costs, including upgrades and maintenance, when choosing automation technologies?


<< First < Previous 1 2 Next > Last >>

No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Learn how to create value with re-use; gain productivity with lean automation and connectivity, and optimize panel design and construction.
Go deep: Automation tackles offshore oil challenges; Ethernet advice; Wireless robotics; Product exclusives; Digital edition exclusives
Lost in the gray scale? How to get effective HMIs; Best practices: Integrate old and new wireless systems; Smart software, networks; Service provider certifications
Fixing PID: Part 2: Tweaking controller strategy; Machine safety networks; Salary survey and career advice; Smart I/O architecture; Product exclusives
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Look at the basics of industrial wireless technologies, wireless concepts, wireless standards, and wireless best practices with Daniel E. Capano of Diversified Technical Services Inc.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.