Automated inspection system for quality control

COGNEX VISION SYSTEMS GUARANTEE THE QUALITY OF PLASTIC COMPONENTS FOR THE AUTOMOBILE INDUSTRY

Thanks to the In-Sight® 5100 vision sensor, OCSA can guarantee that the plastic components they produce for the automobile industry are totally free from faults.

OCSA S.p.A., a company specialising in moulding plastics, produces plastic parts for major organisations operating both in Italy and Europe-wide. One of the cornerstones of the strategy of this company, located in Creazzo (VI), has been the adoption of the most advanced, innovative technologies for automating production and quality control.

100% Control

OCSA received a major order to produce plastic components for the automobile industry. One of the requirements imposed was total exclusion of faults on the components produced. To meet this requirement, the company’s management decided to use a vision system, and their choice was the Cognex® In-Sight line vision systems. The reasons for this are explained by Marco Milan, the owner of OCSA: “First of all, we were aware of the fact that only a vision system would be able to meet our client’s requirement in full, and, in second place, we had already installed a vision solution based on Cognex In-Sight systems to carry out inspection tasks, and this had produced excellent results.”
In this case, the task of the vision system is to check with extreme accuracy the quality of each item produced, and to reject any found to be faulty. In greater detail, this system is able to intercept parts that show imperfections of any kind, such as geometrical defects, excess or lack of plastic material, presence of oil or other impurities on the plastic body.
The vision system was installed on equipment expressly dedicated to monitoring the operation described above. The total equipment consisted, in addition to the vision system, of a vibrating unit that sends through the parts to undergo inspection, a conveyor belt, which moves the parts under the remote camera, and a pneumatic discharge system, which removes faulty parts. The whole system, controlled by a PLC, has been designed and produced by TEC Srl of Lissone (MI), a systems integrator working with Cognex.
As to the vision sensor itself, Ocsa’s technical staff opted for the model In-Sight 5100: this device has been selected for its particular efficiency in terms of processing power, and its sturdy, reliable structure, which means that it can be used in particularly severe conditions.

The importance of the software

Another factor which made a decisive contribution to the decision to use the Cognex solution is the excellent software support: like all the other members of the In-Sight family, the 5100 model is supplied with the full Cognex vision tools library, making available advanced functionalities for the processing and analysis of images.
In the case of OCSA, a tool which is particularly useful has turned out to be PatFind®, a function enabling the In-Sight systems to locate the objects being inspected reliably and repeatably, even in the presence of changes of lighting, angle and scale. Each individual part is recognised and picked up by PatFind. Two geometric options provided by this tool – angle and reference position – make it possible to carry out a detailed in-depth analysis of the geometric characteristics of the object using the edge and blob finding tools.
The results obtained using this vision system have surpassed expectations; all faulty components have been eliminated, while the approved components rejection rate has fallen below 0.5%. Thanks to the high speed of inspection, at 120 parts/minute, there is no negative impact on line productivity.

Seat component vision inspection for assembly

An intelligent inspection solution for smarter seating

As a leading global component supplier to the automotive industry, the Keiper GmbH & Co Group develops and manufactures metal seat components and structures for automotive industry suppliers and manufacturers. Quality control using vision technology on the production line has brought flexible production lines, investment return in under a year and increased efficiency.

Make production more flexible and more reliable

The company’s range of products meets demand in the automotive sector for intelligent adjuster systems and innovative seat structures – both for front and rear. The team at their plant in Germany were looking for new ways to make the presence and variant inspection of components on the production line more flexible and reliable. In the past it used a complex mechanical control system, equipped with a number of touch controls which proved less then dependable.

Challenging : a production obstacle course

Before embarking on a vision solution, the different challenges that would present themselves had to be considered. Various elements in the production process could potentially prove problematic to a vision system:

- some 20 different types of component had to be identified with 100% reliability on each production line
- the individual components needed to be inspected for defects and correct positioning
- components were likely to vary in colour and aspect despite being identical in shape and dimension
- parts may have entirely different colours depending on the supplier
- oily films still present on the surface
- some parts are pitch-black while others have a metallic sheen

In-Sight brings high resolution and accurate object location

Keiper awarded the project to Octum, a Cognex Partner System Integrator (PSI) having considered their vision proposition based on the latest In-Sight® vision sensors. Cognex technology proved capable of providing a vision solution robust enough to handle the challenge. Thanks to the high resolution of the In-Sight 5403 vision sensor, high precision can be assured even for large components when measuring parts offering greater production flexibility. The In-Sight 5400 vision sensor family also benefits from a full range of software tools such as PatMax®. PatMax functions using the geometrical structures of objects (similar to CAD). The most important characteristics of an object such as edges, dimensions, shapes, angles, arcs and shades are isolated, identified and compared to the real-time image. Analysis of the data permits the operator to accurately define the objects position.

Flexible workflow

Reliable feature detection and incorporation of the In-Sight vision sensors in production offer other benefits. For example with the individual component variants there are minor differences as to whether the right or left-hand fitting side of the seat is concerned. Sometimes the right parts are inserted on the wrong side of a seat. Precise feature detection by the vision tools identifies such problems and notifies the operators. The error is corrected and production flow is not interrupted.

Fast - installation in 6 weeks

A complete turnkey system solution was implemented in only 6 weeks. The first control station was installed in June 2006 and has been operating reliably in three shifts including at the weekend since then. Given the satisfactory results, another control cell was established at the Kaiserslautern plant in February 2007. During this time the customer-specific user interface Octum designed for Keiper has proved to be ideal, making programming child’s play for machine operators and maintenance staff.

Real time return on investment

The targets set for the paying back of these production investments are less than a year at Keiper. Markus Röder, one of the people at Keiper responsible for opting for the vision system commented: “Employing a reliable international vision supplier like Cognex offers benefits which have a long-term impact on the entire group and its international production network.”

Robot guided valve inspection

Robot-guided inspection system ensures correct engine assembly at Ford

International Truck and Engine Corporation has recently implemented an innovative robot-guided inspection system at its manufacturing plant in Indianapolis, Indiana to verify the proper placement of valve bridges during assembly.

The diesel engines, which are produced for large Ford pickup trucks, feature 16- valve bridges, which sit on top of the engine’s valve stem.  During head assembly, the valve bridges are placed on top of the valve spring and a rocker arm is placed on top of the bridges.  This whole assembly is then placed onto the engine.  Prior to being installed on the engine, the valve bridges are only loosely held in place by the rocker arm.  It is necessary to inspect each one to ensure they are positioned accurately and that none of the components have become misaligned.

While the company has always achieved accurate, 100% inspection of its engine components, the inspections had been carried out manually.  An operator would look down into the engine assembly, check each individual valve bridge for placement, and mark each one with a paint pen to indicate that it had been inspected. The process was slow and costly from a labor standpoint.  The time had come to automate.

Having successfully implemented robots in other areas of production, International felt that a robot might be useful in this case, and called on CIM SYSTEMS INC., a Noblesville, Indiana-based systems integration firm that specializes in robotic automation.  According to Tony Hillers, a CIM SYSTEMS engineer assigned to the project, a robot-guided inspection station was the perfect solution.

“We all felt that robot-guided vision would be the most flexible solution in terms of being able to automatically inspect the parts inside the engine,” he explains.  “They could have set up a little finger probe that actually touched the part to do the verification, but the parts are difficult to approach consistently.  With vision, we’d be able to avoid any problems associated with a contact approach.”

One of initial ideas for a vision system, Hillers adds, was to have 16 separate vision cameras mounted above the inspection point, allowing for one camera per part.  The problem with this approach, however, was that the engine assembly is very full with components, and wires and other parts often occlude the valve bridges.  “We needed a way to allow a single-vision camera to move in and around the engine assembly in order to actually get a look at the parts even when other things are obscuring them.  Positioning the camera with a robot allowed us to implement logic that enabled the robot arm to try to see the valve bridge from multiple angles.”  Hillers also notes that a 16-camera vision system would have been an expensive option, and would require a great deal of maintenance.

The main components selected for the project included a single Cognex In-Sight 3000 vision sensor and a six-axis ABB IRB 140 robot.  The In-Sight 3000 is a high-performance machine vision sensor that consists of a industrial-hardened, DSP-based vision processing unit, high-speed digital camera that easily mounts to the robot arm, onboard light control, built-in discrete I/O, and a pre-installed vision library of greyscale vision software tools.  The In-Sight 3000 also provides a standard VGA output for real-time display, built-in Ethernet communications, and an onboard serial port which is used to link to the ABB robot controller.

To set up the 16-point inspection routine, Hillers used the In-Sight vision sensor’s spreadsheet interface.  With the look and feel of a traditional spreadsheet, the In-Sight vision spreadsheet enabled him to quickly select vision tools and parameters from drop-down menus, and configure a customized operator interface to make day-to-day operation of the system easy for line operators, technicians, and maintenance staff at International.  “It was easy to explain how it works to shop floor personnel,“ says Hillers, “and people with no programming experience were able to make changes to the program in one day.  If you can understand Microsoft Excel even a little bit, then you can pick up on it and go with it.”

Engine blocks come into the cell on a floor-mounted conveyor, each sitting in its own nested pallet.  Once an engine is present, the IRB 140 hovers over the engine block, positioning itself this way and that so that the vision camera can get a good view of the parts.  If the camera can’t see a part, the robot repositions itself at various angles until the part becomes visible.  To increase visibility, the parts are illuminated with a combination of a ring light, which is attached to the tooling on the end of the robot arm, and side-mounted fluorescent lighting.

Once a valve bridge is in view, the robot controller sends a signal to the vision camera to capture an image of the part.  The image is then sent to the In-Sight vision processing unit, which is mounted in the robot controller enclosure, and processed with In-Sight’s PatFind™ tool, a geometric pattern-matching software tool that verifies the proper position of the part despite any occlusions or variations in part appearance that may exist.

According to Scott Hauger, a CIM SYSTEMS applications engineer who worked on the project, pattern-matching performance factored heavily into the decision to go with the Cognex system.  “The valve bridges have a unique shape, and with so many components in the way it’s critical that the vision system is able to pick out the right features,” says Hauger.  “The PatFind tool does just that”

PatFind analyzes images using geometric information in place of pixel grid-based correlation.  For example, it interprets a square as four line segments and a football as two arcs.  By analyzing the geometric information from a part’s features and spatial relationships, the PatFind tool is able to precisely and repeatably determine the precise position of each valve bridge in the engine regardless of how it appears.

As each of the 16 valve bridges is inspected, operators can view a live image display of the parts on a nearby color monitor.  The display lists the different valve bridges by cylinder number, and provides pass/fail information for each inspection.  If all 16 parts pass inspection, the engine proceeds down the production line to a testing area.  If a failure is reported, the robot controller passes the information to a line control system to be written to an RF Identification tag.  At that point, the engine goes into a repair loop where an operator manually inspects the parts in question.  It is then re-routed through the cell and inspected by the In-Sight system again.

Since the robot-guided inspection system was installed, it has been running non-stop for two shifts per day without any problems.  According to Hillers, product quality has remained consistently high, and International is pleased to add this project to its long list of successful automation stories.

Assembly line upgrade for defect elimination

120,000 automotive parts manufactured by Meister are checked each day using Cognex machine vision

Cognex Corporation (NASDAQ: CGNX), the major global supplier of vision systems, sensors and bar code readers, presents an example of an application using industrial vision in precision mechanics. Intended for automobile equipment manufacturers, the parts manufactured by Meister France are subjected to very strict appearance checks with the aim of completely eliminating defective parts before delivery to customers. An ambitious gamble when you are producing almost 40 million parts per year. A gamble which has paid off thanks to Cognex In-Sight® industrial vision sensors.

The Meister Group is a Belgian industrial group mainly supplying the automobile market. The company has factories in Belgium, France and the Czech Republic specialising in the mass production of cut steel parts.
The challenges for these modern production units, which use specialist precision lathes, is to manufacture relatively complex parts in a few seconds, and to guarantee the conformity of the parts on delivery, without ignoring the essential and continual search for gains in productivity.

In France, the Meister factory is located at Scionzier, in Haute-Savoie. It manufactures electric valve parts for automobile equipment manufacturers specialising in ABS braking systems. Nearly twenty-four multi-spindle lathes produce 120,000 parts each day, representing an annual production of 35 to 40 million parts.

The demand for quality is the main problem on which all of its efforts are concentrated: it has to try and avoid delivery of defective parts to customers. In a sector where the smallest incident on an assembly line can bring about exhaustive investigations and can lead to complicated and costly procedures for the subcontractor, the search for Zero Faults is the only acceptable way forward.
However, the manufacturing techniques used and the demands of mass production do not allow such an objective to be reached directly from the use of machines. Checking and sorting has to be carried out in order to remove defective parts, with the faults consisting of missing components, metal shavings, loose components, damage from vibration or knocks…

Checks were previously carried out by the naked eye by operators which limited the number of defective parts to around 1 in a 1000. This was still too many, and so studies had to be carried out in order to reduce this rate as a value lower than 100 ppm was aimed for. It was also necessary to work on reducing the impact of manpower costs on the cost price of the parts.
Considering the automation of these checks by vision tools was a natural approach for Meister’s technicians, who already had experience of industrial vision systems for a dimension checking application. A seminar organised by the Alpsitec company also allowed them to find out about the performance and capacities of the In-Sight vision sensors, made by Cognex, the world leader in industrial vision.

Alpsitec is an approved partner system integrator of Cognex. The company was called upon to carry out a demonstration directly on the production line so as to verify that the Cognex cameras were capable of “seeing” the faults they had to detect. After this first feasibility test, a prototype was brought up to date and assessed over a month. The simplicity of the use of the In-Sight sensors was a decisive factor in the choice of the system. The Terms and Conditions were drawn up and two test systems were ordered.

The checking system – in fact two independent test benches – was installed at the end of the production line in order to carry out a final check of the parts just before they were packed. All the parts produced were sent to this control point, therefore 100% of the production is checked.

The parts are put into their packaging – the mesh – by a robot. Once the packaging is completed, the robot picks it up and places it on the test surface. Then the robot takes hold of the Cognex In-Sight 1000 vision sensor linked to a lighting system and passes it along the mesh, over the parts. It’s important to remember that the vision sensor must inspect each part in order to detect any of the four types of faults to be removed: presence of metal shavings, missing components, loose components, and damage from knocks or vibration. The sensor sends information on the checks carried out to the robot’s control centre. The robot puts the vision sensor down and takes the defective parts and deposits them into a chute – one chute for each type of fault – which then carries them to a hopper. Then the system continues its operation.

One of the test benches is fitted with two In-Sight 1000 vision sensors and operates at a rate of 6000 parts per hour. The other system comprises a single sensor and works at a rate of 4000 parts per hour. Both systems worked as dual sorters during the first few months of the operation.

The important part of the work of updating the application consisted of identifying the various faults which the checking systems had to recognise and to “teach” them to the vision sensors. This procedure is essential for optimising the efficiency of the checking system.

The rate of faulty parts delivered to customers has rapidly dropped to 40 per million. The power of the processor algorithms of the In-Sight sensor and the finer analysis of the faults to be removed should allow this rate to be brought down even more to below 20ppm.

Jean-Marc Sermet, Technical Director of Meister France, has supervised this project from beginning to end. He is very pleased with Cognex products and Alpsitec’s service, the combination has provided him with the necessary skills and experience in setting up vision solutions in industry. “Above all, we are engineers specialising in precision metal cutting”, stated Mr.  Sermet. “Alpsitec’s contribution has allowed us to make rapid progress on this project and to benefit from efficient and reassuring support.”

Alpsitec has also trained a technician who has been able to rapidly take charge of setting the vision sensors’ parameters. So Meister is able to input data by itself for new types of faults to be learned and for modifying the parameters in relation to the 15 different types of parts to be inspected.

“We were concerned that these test systems would slow down production rates. We have noted with satisfaction that the implementation of these industrial vision solutions do not have a negative effect on production”, added Jean-Marc Sermet. “The solution used appears to be particularly stable, and the operators do not have any need to intervene.”
The biggest reward is that there has been a real return on investment in less than six months. Customer relations have been strengthened from the significant improvement in quality. Meister is currently looking at other applications for industrial vision on its production lines.

Cognex Technical Firsts

Cognex has more than 200 patents in machine vision, and the largest team of machine vision experts anywhere in the world. Below are a few of the significant technical advances pioneered by Cognex:

• First industrial optical character recognition system (DataMan) – 1982
• First normalized correlation pattern finder (Search) – 1986
• First single-board OEM vision engine (Cognex 2000) – 1986
• First patent for dedicated vision chip (VC-1) – 1991
• First full-capability machine vision system for VME bus computers (Cognex 4000) – 1991
• First advanced vision system for PC/AT bus personal computers (Cognex 5000) – 1993
• First “third-generation” easy-to-use machine vision system (Checkpoint) – 1994
• First PC plug-in Data Matrix 2D code reading solution (acuReader/2D) – 1996
• First high-accuracy, high-speed, high-yield, object location technology (PatMax ®) – 1997
• First compact, high-speed industrial machine vision camera (CVC-1000) – 1998
• First full-capability machine vision sensor (In-Sight 2000) – 2000
• First industrial machine vision sensor with Ethernet / IP (In-Sight 1000 and In-Sight 3000) – 2001

Machine vision applications

The majority of manufacturers served by Cognex today are in the semiconductor, electronics, automotive, aerospace, pharmaceutical and medical device industries. Typical applications include:

• Verifying presence of electronic components
• Ensuring that pharmaceutical packages have been correctly labeled
• Verifying presence of critical fasteners and bolts in automobiles
• Ensuring that safety seals on bottles are present and intact
• Reading ID codes on aircraft engine parts and tracking their manufacturing history
• Guiding assembly robots in automotive factories and electronics manufacturing equipment

Unusual machine vision applications

Cognex vision sensors are used in smaller numbers in virtually every nook and cranny of modern industry. Here are some of the more unusual applications of Cognex technology:

• Checking the sex of chickens—before they are born!
• Grading the quality of potatoes
• Measuring the growth of bacteria in a Petri dish
• Inspecting beer kegs for leaks
• Inspecting coffins
• Sorting books by looking at their covers (Cognex CAN tell a book by its cover!)
• Checking for sediment in bottles of champagne

DVT 535C offers complete set of easy to use color tools

Natick, MA, February 14, 2007—Cognex Corporation (NASDAQ - CGNX), the world’s leading supplier of machine vision sensors, today announced the DVT® 535C, the most capable and easy to use color vision sensor in it’s class. With a full suite of vision tools, the DVT 535C sets a new cost/performance standard for entry-level color vision sensors.

“Unlike most low-cost color vision sensors, the DVT 535C is not limited to a single machine vision function such as color sorting, but can handle a much broader range of applications with a compete set of color tools for sorting, color match and defect detection,” said Kris Nelson, Cognex Senior Vice President, Vision Sensors.

The DVT 535C is the lowest cost model in the DVT color vision sensor family that includes a choice of high-speed and high-resolution products to meet a range of performance requirements. Like all DVT vision sensors, the 535C operates with easy-to-use Intellect™ software that facilitates setup, integration, and maintenance, and is backward compatible with FrameWork.

Cognex is also pleased to announce the latest Intellect software release 1.4 with many enhancements including a new Flexible Flaw Detection (FFD) tool that provides reliable inspection results despite random process variations. FFD reduces inspection errors when the appearance of the part is not consistent due to registration errors, lens and perspective distortions, and normal part-to-part variations.

The DVT 535C vision sensor and Intellect 1.4 are available now.

Fun facts about Cognex

• Cognex stands for Cognition Experts
• Cognex Founder Dr. Robert J. Shillman carried out research in human visual perception at the Cognitive Information Processing Group at M.I.T., where he received his doctorate degree in 1974
• Since 1981, Cognex has shipped more than 300,000 vision systems, more than any other vision company
• When Cognex’s first vision system, called “DataMan,” read its first character in 1981, the company’s three founders started a tradition of drinking a champagne toast to mark important company milestones. Today, the lobby of the company’s headquarters in Natick, MA includes a three story “Wall of Fame” covered with champagne bottles, each symbolizing a significant company achievement
• Cognex sold its first vision system to IBM, where it was used it to read serial numbers that were etched by laser on the surfaces of semiconductor wafers.
• Virtually every semiconductor chip manufactured in the world today is made with the aid of machine vision, and most of them are made with the help of Cognex’s vision systems
• CEO Robert J. Shillman, who has made his fortune from the success of Cognex, has not taken a salary since 2001, and since 2004 has asked the company to donate his annual bonus to charity
• Cognex founders Shillman, Silver and Matz received the 2005 SEMI award from Semiconductor Manufacturers International (SEMI), for their significant technical contributions to semiconductor manufacturing, and in 2004 were featured in Fortune magazine as “Heroes of Manufacturing”

COGNEX ANNOUNCES PANEL-MOUNT VIEWER FOR CHECKER VISION SENSORS

Natick, MA, September 25, 2007—Cognex Corporation (NASDAQ - CGNX), the world’s leading supplier of image-based sensors, today announced SensorViewTM 350, a compact, industrial, panel-mount display for its Checker® 200 Series inspection sensors. SensorView 350 allows operators to view production images of the parts that Checker is inspecting without a PC. SensorView 350 features a simple interface for displaying images of passed or failed parts, along with status indicators and results statistics to more easily monitor the production process.

“Checker 200 Series inspection sensors provide a tremendous amount of useful process data compared to traditional sensors,“ said Justin Testa, Cognex Senior Vice President and Group Business Manager. “SensorView provides easy access to that information so factory floor operators can better understand how the manufacturing process is working.”

SensorView 350 achieves an IP65 rating and will be available in October.

COGNEX INTRODUCES NEW CHECKER VISION SENSOR
Checker 232 inspects small features over a wide area

Natick, MA, February 19, 2008—Cognex Corporation (NASDAQ - CGNX), the world’s leading supplier of machine vision systems and vision sensors has added the Checker^® 232 model to its award-winning Checker vision sensor product line. Designed to inspect small features over a wide area, Checker 232 provides reliable inspection results on the fastest production lines, detecting and inspecting up to 1,500 parts per minute.

Checker 232 is ideal for applications where small features are being inspected on large parts, such as the inspection of clips and springs on large automotive assemblies.  Checker 232 is also ideal when a much longer working distance is needed and the vision sensor must be mounted far from the area to be inspected.

“Customers value the simplicity and power of Checker vision sensors because they offer a very cost-effective option for inspections where traditional sensors are not reliable and a full-blown vision system is too expensive,” said Pascal Dorster, Senior Director, Vision Sensors Business Unit. “The Checker 232 extends the versatility of the Checker product line so customers can solve a broader range of inspection applications more effectively.”

Unlike traditional sensors, there’s no limit to the number of part features that a single Checker can inspect.  Checker uses patent-pending multi-image analysis to determine if a part is present without an external trigger, greatly simplifying installation. This unique capability also enables Checker to track parts in varying positions along the production line, overcoming imprecise part positioning and delivering consistent, precisely timed pass/fall results. No other sensor, vision sensor, or vision system can do this.

The Checker 200 series are simple to set up, small enough to fit almost anywhere, and offer IP67 protection. Checker 232 joins three existing 200 series models: The Checker 200 for part detection, the Checker 201 for part detection and inspection, the Checker 202, with ladder logic when more complex pass / fail decisions are needed. The Checker 232 combines the features of the 202 with the ability to inspect smaller features over a larger area. Checker 201, 202 and 232 are available with the Cognex SensorView^TM 350, a compact, industrial, panel-mount display. The Checker 232 is currently available.

COGNEX EXPANDS INSPECTION CAPABILITIES OF CHECKER VISION SENSORS
Model 252 adds pass/fail inspection of height, width, and diameter

Cognex® Corporation (NASDAQ - CGNX), the world’s leading supplier of machine vision systems and vision sensors, has expanded its Checker vision sensor product line with the Checker® 252 model. The 252 includes all inspection capabilities of the award-winning Checker vision sensor family, plus additional software sensors that verify height, width, and diameter and deliver reliable pass/fail results on high-speed production lines.

Key to the simplicity of the Checker 252 is its One-Click Setup™. By simply clicking on the center of the part feature to be inspected, an image of a familiar caliper appears and locks on the edges of the part feature, sets the minimum and maximum thresholds, and learns edge polarity…all automatically.

“With its unique screen caliper, the Checker 252 makes pass/fail measurement verification simple and reliable” said Pascal Dorster, Vision Sensors Business Unit Manager. “Manufacturers in many industries, such as automotive and packaging, can now verify dimensions of parts with very low-contrast edges and solve a wide range of measurement verification tasks not possible with photoelectric sensors.”

As with other Checker models, the 252 is available with the Cognex SensorView^TM 350, a compact, industrial, panel-mount display. The Checker 252 will be available in November, 2008. For more information, please visit http://www.cognex.com/checker252.