Avoid Costly Mistakes: Essential Tips for Perfect Machine Vision Lighting
Occasionally, machine vision illumination assessments result in the worst situation possible for the client. They work with an integrator for weeks, exchanging information about the application and then making revisions to the lighting solution until a meeting is held and it is decided that the application is not practical.
This situation often arises when engineers make false assumptions and misconceptions regarding machine vision, which can have serious repercussions that could lead to a project's complete termination or significant delay in its completion.
Acknowledging Misconceptions
There are five broad categories into which these misconceptions can be divided:
The worst-case scenarios can be avoided by identifying these incorrect assumptions: wasting time on a project that was never going to happen, postponing a project due to an expensive redesign after the machine is built, or giving a customer a system that never functions the way they had hoped.
When to Take Into Account Visual Inspections
The most significant myth is that visual inspection should only be taken into account after the machine is built. The application won't have the best answer or won't be able to be solved if physical limitations in the system architecture prevent you from using the best light for it. By considering the needs of the vision-system from the beginning, this can be prevented.
The illumination and camera's clearance is a crucial factor. An application's light working distance (LWD) can make all the difference. If there are physical obstacles preventing you from installing the light where it needs to be, you won't be able to get the best picture, regardless of whether you need to install the light closer to the object or farther away.
Engineers should include a brighter light in the system design if a machine is planned to operate at a rapid pace so that the intensity is suitable for the exposure period. Furthermore, if ambient light produces undesired glare, you can incorporate a bandpass filter, utilize a quicker shutter speed, or create a shroud into the design to eliminate the glare's negative effects on the image.
Another important thing to keep in mind is to present the item to the camera, particularly if you are evaluating some or all of the workpiece's sides. Enough room is needed for several cameras, or the machine must be built to be able to move the part in order to inspect all pertinent sides. Your workpiece's fixture may also be obstructing your light's ability to properly illuminate it.
In order to make sure that the infrastructure and space required for vision components are included, engineers should consider the physical needs of a vision system early in the design process. If not, a pricey redesign can be required later on in the project.
Unsuitable Project Scope
There are two interpretations of "bad." Initially, the scope attempts to achieve too much above what is practical. Alternatively, it indicates scope creep, when the project's original parameters increase to incorporate new features that exacerbate the needs for the vision system.
It's common for engineers to believe that a single vision system can inspect far more than is actually feasible. However, it is frequently impractical to require constant, 100% accurate sample inspection. Attempting to check a workpiece with too much fluctuation in its height or curvature, inspecting it with a field of view (FOV) that is too large, or inspecting the complete workpiece provide additional obstacles.
An excessive amount of inspection does not always indicate that there are too many inspection duties. When engineers attempt to perform too many complex examinations with a single camera, problems arise. particularly when the field of view is wider and the data being examined is dispersed. dividing up inspection work among several cameras can frequently make an application less challenging overall.
Examining with a too wide range of view has a comparable subtlety. A flood light can be used to handle presence/absence problems in clear situations, but it becomes problematic for applications requiring high-precision lighting and a wider field of view. For an application to function, the FOV needs to be narrower than the 300 mm size limit that many common precision light form factors have. An analogous issue is when there are too many samples in one image. Depending on where they are in the image, optical elements can alter the viewing angle of samples. The size of the FOV and the telecentric lens must coincide for a more consistent angle.
Finally, when there are frequent profile changes, it is difficult to design a lighting configuration that will support all features on every workpiece. When checking several metal workpieces for scratches, this frequently happens. Due to the complexity of the setup, it is more practical to narrow the scope in one of three ways: create a setup specifically for the most important sample, inspect only the flat surfaces, or construct a robot-assisted system that can perform several inspections, one for each type of workpiece.
When several stakeholders add more inspection jobs to the initial scope during the development phase, it is commonly referred to as scope creep. A straightforward application develops into an overly complex system that is unable to successfully accomplish any of the set goals. After that, the project is shelved without resolving the original issue.
Well-defined project boundaries will specify the activities that must be completed by the application in order to support project advancement. Maintain a separate list of activities that you can add to the evaluation; these tasks won't be incorporated unless they represent relatively simple adjustments to the essential answer.
Testing Conditions and Samples
There are several incorrect presumptions about the testing settings and samples. Engineers frequently test systems using small sample sizes, which results in systems that function well in the lab but malfunction in a real-world production setting where defect variance is much greater. The distinction between one good sample and one bad sample is simple to make. However, testing with all possible variations of excellent samples and all possible variations of bad samples, including borderline cases, increases the likelihood that evaluations will identify the optimal option. You may make sure the system can handle variability in the actual world by testing a big number of samples as they will appear when they get to the inspection step.
We know a customer has assumptions about testing circumstances when they ask for a lighting advice based on a light's lux or lumens. Because it's not always easy to select the correct light. When the LWD rises, a light's irradiance first drops. Furthermore, the homogeneity of the irradiance changes not only in size but also in shape over the area it illuminates. The properties of your sample also influence its light-interaction behavior. More light is absorbed by dark samples than is reflected by bright samples. Choosing a light should not be based solely on brightness; instead, it is better to determine whether the form factor, size, and wavelength of the light are suitable for the intended use before speaking with the manufacturer about overdriving the light or getting a strobe version of it to achieve the required brightness.
It's vital to provide as much information as you can regarding your application because of this. You might believe that a certain design element has no bearing on the visual system and, thus, need not be disclosed to the manufacturer. However, in this particular scenario, excessive communication is beneficial. In contrast to that worst-case situation, it can assist you in avoiding an extended evaluation phase because the lighting evaluation will be carried out with full awareness of all the constraints from the outset.
Prior Application Experience
It is not uncommon to encounter unforeseen difficulties while attempting to apply a solution that worked well in one application to another that is comparable. Every application has its own limits and features; therefore, a solution that works in one situation might not work in another without some modifications.
A polarizer on a flat dome light, for instance, can address the problem of distinguishing a certain kind of flavor packet. However, it is impossible to read the packet in another similar application that looks at instant ramen packets, where the orientation of the packet is occasionally at a 45° angle. Should this reliability issue come to light until after the system is shipped to a client, the device may wind up gathering dust in a corner.
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Engineers should refrain from using a "copy-paste" method. They ought to test the light before buying it if they ask a lighting company to suggest one based on previous uses. This guarantees that a solution is customized to the unique requirements and circumstances of the running application.
Eyeing versus Detecting Flaws
Finally, it's important to understand the difference between detecting and seeing flaws. A machine vision system may not identify a flaw simply because a human can see it. Since vision systems lack human judgment, their only means of identifying flaws are contrast, patterns, and predetermined criteria. An apple with a bruise on it can be identified as such by looking at it. However, machine vision is limited to identifying the bruise as apple discolouration. Machines are not able to observe or assess as exactly as the application may require, whether it be a color difference that can pass inspection or a flaw that needs to be filtered out.
Engineers need to be aware of the limitations of technology, even as emerging tools like artificial intelligence (AI) have the potential to narrow the gap. By doing this, they may create systems that, taking into account every factor that could have an impact on performance, detect what they are designed to recognize with reliability.
Cooperation and Interaction with Interest Parties
Early in the design process, involve all pertinent parties, such as maintenance staff, quality control teams, and end users. Their knowledge can offer vital details regarding particular inspection requirements and operational restrictions, guaranteeing that the vision system meets practical demands.
Combining with Different Systems
Make plans for integrating your software and other automation systems. Assuring interoperability with current production line hardware and control systems is part of this. Early thought of data formats and communication protocols can guarantee smooth functioning and save expensive retrofits.
Environmental Elements
Take into consideration the operational setting in which the machine vision system is going to be used. A few examples of the variables that can impact lighting and camera performance are temperature swings, dust, and humidity. These problems can be lessened by putting safety precautions in place or using the right tools.
Maintenance and Calibration
To guarantee constant functioning, establish a regimen for the vision system's calibration and maintenance. Accuracy may be impacted over time by changes in camera settings and lighting. Consistent inspections and calibrations can stop a system's performance from declining over time.
Benefit-Cost Analysis
Analyze the costs and benefits of several lighting options in-depth. Expensive lighting solutions might perform better, but they might not be required in every situation. Optimising investment without sacrificing quality can be achieved by striking a balance between cost and needed inspection level.
Education and Experience
Give engineers and operators thorough instruction on the ins and outs of machine vision and lighting systems. Reducing downtime and increasing system effectiveness can be accomplished by optimizing settings, resolving frequent problems, and understanding the fundamentals of operation.
Simulation and Prototyping
Model and test the visual system under different settings during the design process by using simulation and prototyping technologies. This can help save time and costs by identifying any problems early and allowing for improvements before full-scale adoption.
Tailored Approaches for Challenging Inspections
Custom illumination solutions should be taken into consideration for complex inspection activities that entail high variability or flaws that are hard to detect. Work together with lighting manufacturers to create custom systems that meet the demands of certain applications while guaranteeing peak performance.
Record-keeping and Documentation
Ensure that the phases of design, testing, and implementation are meticulously documented. This involves keeping a record of every assumption, choice, and modification made during the project. Thorough documentation can help with audits, improvements in the future, and troubleshooting.
Future-Proofing the Framework
Make sure the system is future-proofed throughout design. Be prepared for future updates and scaling needs. Make sure the system can integrate new technologies without needing to be completely redesigned, such as AI improvements or more inspection capabilities.
Engineers that approach applications with the correct expectations are better equipped to create a project scope that is realistic and conduct a thorough review that takes into account all relevant elements before any construction begins. There are more completed systems supplied to clients who receive exactly what they paid for, and fewer projects are shelved.
As you embark on your next machine vision project, remember that success begins with meticulous planning and informed decision-making. By addressing potential pitfalls early in the design phase and leveraging the insights shared here, you can avoid costly delays and ensure your system performs optimally.
Ready to optimize your machine vision lighting? If you’re facing specific challenges or need tailored solutions, reach out to our team of experts today. Let’s work together to deliver a machine vision system that exceeds your expectations and meets your operational goals.?Contact us now at 1-888-600-3080 and take the first step towards flawless vision inspection!
Global channel strategist | Industrial automation | I create mechanisms to develop relationships and drive disruption and innovation in manufacturing.
7 个月Great insights here! Who waits to think about the camera and lights after the whole machine's put together? That's like planning a road trip but forgetting to check if the car has gas. ???? It’s all about nailing those details early. And avoiding that scope creep? Absolutely crucial. Because nobody wants to end up with a vision system that’s more of a decorative piece than a useful tool.