5 Things You Should Know About Your Vision Application
1. What are the Operating Conditions?
This is the typical “operating environment” question. This will determine any special needs required by the camera and associated components to be installed. Many inspection devices are only rated IP20, this is acceptable for a few installations but most will require at least some extra protection.
2. What are the Inspection Needs?
This is where we see many applications meet an un-timely demise. Often the specific trait or quality to be inspected is not defined, or at least it is not in a written documented form. For example; if you are interested in identifying surface defects they should be classified by size, shape, color and possibly quantity. The current vision systems available on the market today require programming or “training” to look for specific defects. They are only effective for defects that can be identified by the vision and programmed as good or bad traits to report.
3. What are the Reporting Needs?
Every company has its own very unique reporting and recording needs that are to be met by the vision system. All basic systems will provide a simple relay signal for each inspection to indentify it as a pass or fail. Most of the basic dedicated vision sensors only have this capability. Most of mid to hi end vision systems have the ability to log pictures and statistical data on the inspections performed. Many of these higher end systems can also be connected into the plant data network to store data remotely.
4. What are the Application Needs?
This is where we make sure the vision system meets the process needs. To select the correct vision system we need to know the production specifics such as; line speed, product size, interface needs and product color. These may be fixed or they may have multiple options for one or all of these aspects. Quite often it is the multitude of product variables that increases the vision system complexity from a simple vision sensor to a more involved vision system. What you will find on today’s market is a very broad product offering of vision inspection equipment. In recent years large steps have been made on capabilities, quite often the very basic system has the ability to identify the defect but may not be able to meet the other needs such as data-logging, processing speed, or even operator interface capabilities.
5. What are the System Integration Needs?
This is one area that we typically find has been discussed and planned. Basic vision systems can provide a simple relay and hardwire connection to the machine control system. Expanded capabilities and needs include network control and data collection. Many vision systems are capable of communication directly with PLC’s on the market for control and status signals. Your needs may include historical trending or even logging of the actual pictures for quality control purposes. All of this is possible with the selection of the correct hardware.
6 Steps For Implementing a Successful Vision Application
1. Identify Needs
It is crucial for a successful vision inspection system that the inspection criteria be defined up front. Don’t forget, not everyone is intimately familiar with your process and product. Many things you may take for granted are not immediately evident to everyone else.
2. Identify Resources
Identify in-house resources along with capabilities and expectations for the long term success of your application. Especially true for the first system, you very likely will find it more cost effective to utilize an engineering source to get you going on the first system. Even if you don’t want to become an “expert” in vision applications it will be very beneficial to have an in-house resource identified as a first level response when questions arise during daily operations.
3. Product Testing
Testing of samples or even better on-line testing will provide a much better opportunity to test the vision system on your application. During testing it is important that a broad array of defects be presented to the vision system. Vision systems are taught to respond to specific characteristics. If you are able to present every possible variation of defect during the testing you will likely have a very functional and robust inspection system from day one.
4. Detailed System Design
Utilizing the data collected during the testing phase we can provide a detailed system design. This design will include selection of the appropriate vision system including lighting, operator interface needs, optics and any associated brackets and process integration.
5. Implementation Planning
A correctly planned installation and startup that includes training for operation and maintenance will complete the successful implementation of your inspection system.
6. Acceptance Testing
This is where the ability of the system to meet the needs identified in step 1 are validated.
Vision Basics For Automated Vision Inspection Systems
It is NOT our intent to promote one vision manufacturer over the others. It is our normal procedure to test every vision application presented to us before we provide a quote. Quite often we test the application on multiple systems to verify that we will be providing the best option for the application. Usually we find that you will have options for solving your vision inspection application.
The following is a list of vision related topics that I find are common.
- Levels of vision systems
We have compiled a basic list of Vision related terms and defined them for your reference.
In this downloadable PDF you will find answers to common vision questions such as;
- What lens do I need?
- What is the difference between a CCD system and a CMOS system?
- What lighting will work on my application?
One common misconception for many people new to vision inspection is; if you can see it or read it with your eyes it should be easy for a vision system to perform the evaluation. The problem with this expectation is that your brain is thousands of times smarter and faster that any vision system. You are using a lifetime of past experiences to help you evaluate the image you see. Every vision system on the market uses only data that we program into it to aid in evaluating the image.
Another thing that most people don’t realize is the standard vision system is black and white, and it will evaluate what it is presented based on contrast. Due to a lifetime of experience evaluating images in color it is usually a little difficult to see the same image the vision system will. This can create a little confusion at times, sometimes what we can see with our eyes the vision system has a hard time distinguishing because of a low contrast level. The opposite is true more often than not, the vision system is able to see defects that we have a hard time manually identifying.
Certain color combinations can make this task more difficult than others. Below are a couple of examples of how a monochrome vision system will look at the image we see with our eyes.
Download Vision Basics PDF