Ease of use is only one piece of the machine-vision puzzle
A discussion with Brian Durand of BD Automation
A discussion with Brian Durand of BD Automation
BRIAN DURAND is cofounder of BD Automation (Burnsville, MN, USA; ww.bdautomation.com) and president of its Vision Solutions Group. He has a B.S. from the University of Minnesota Institute of Technology. With 15 years of industry experience, he leads development of turnkey machine-vision solutions. Editor in chief Conard Holton talked to him about trends in systems integration.
VSD: How is each OEM component that you use more or less important for applications you serve?
Durand: One of BD Automation’s strengths is in selecting the best off-the-shelf components for each project. Since we are not tied to any vendors, contractually or otherwise, our staff has gained experience using a variety of hardware and software and is positioned to independently recommend the best components for a customer’s needs.
The first thing that new vision-system users are told is that it is all about the lighting. Select a better light and the vision system will give you better results. While this is certainly true, many types of lighting still are not correctly packaged for dusty or washdown conditions. Lighting is sometimes a compromise between the ideal light source and what is available for a harsh environment, and software is asked to make up the difference.
The image-processing software selected for a given application can be just as critical as lighting. A common fallacy is that if a human can distinguish between good and bad images, most any software can do the same. In reality, each vendor’s image-processing library has its own unique strengths and weaknesses. A few software vendors have introduced what we view as the next generation of image-processing algorithms. These tools have helped us to greatly increase the reliability of our solutions, and we view our expertise in their application as a differential advantage.
VSD: What market changes are driving the implementation of new technologies that you choose for these applications?
Durand: First and foremost, customers are asking for better inspection results. Installing a machine-vision system is no longer a novel idea. Typical manufacturing plants now have many vision systems installed. They know that some systems were designed better than others. We always keep system performance in mind as we evaluate new technologies.
Second, everyone wants equipment to be easier to use. Companies implementing lean manufacturing need rapid product changeover and do not want to have valued maintenance technicians wasting time with tasks an operator should be able to perform.
Last, the introduction of smart cameras has changed what customers expect to pay for a turnkey vision system. An example of how BD Automation has addressed this challenge-while still delivering top performance and ease of use-is the integration of IEEE 1394 [FireWire] industrial cameras. We avoid the cost of a frame grabber while delivering the benefits of high-speed, high-quality images.
VSD: How do you integrate industrial control systems and material handling into these applications?
Durand: Customers prefer buying a machine-vision solution complete with related electrical controls and material handing from one vendor. Rather than having to micromanage several companies, most customers prefer that one vendor assume project responsibility.
At BD Automation, we prefer this, as well. Because part presentation and illumination are so interrelated, there are often opportunities to design a better solution by having the machine-vision engineer work very closely with the mechanical engineer. The engineers work best together when they both have the same goals and the same boss.
VSD: What are your approaches to marking and coding products, and how do you expect them to change in the future?
Durand: Recognizing that product marking and coding go hand-in-hand with machine vision, we have built informal affiliations with several companies that manufacture related products. While we are always free to select the component that best meets a customer’s needs, we recognize that our customers can benefit from the specialized expertise of these affiliates. As an independent integrator, we see it as our role to help bring together the components and companies that can best solve a problem.
VSD: Have you considered using a “system” supplier that has already integrated components into a single “vision solution” system instead of off-the-shelf components?
Durand: Ten years ago there were few standards that defined component interfaces. It could take a considerable amount of time to configure a frame grabber to communicate with a particular camera, or even with a strobe controller. We therefore found value in purchasing systems complete with frame grabber, camera, light controllers, and related software from a single vendor. Two disadvantages of this approach were high cost and relatively few hardware choices available.
All that changed about five years ago. The advent of standards such as Camera Link and IEEE 1394 DCAM greatly expedited integration and testing. We are now free to select the camera that best fits our customers’ needs from any one of a dozen quality camera manufacturers. We can match a PC frame grabber to the project’s requirements and even build 100% digital systems without any frame grabber at all. We can now build lower-cost systems more rapidly while delivering performance optimized for the customer’s exact needs.
VSD: Are PC-based vision systems obsolete?
Durand: PC-based vision systems are anything but obsolete, at least in the FDA-regulated industries BD Automation serves. But let’s first consider “smart cameras”.
A smart camera basically shoehorns an image processor into the same physical housing as an image sensor. This is good for some applications, as the package is small and the customer doesn’t need to know anything about how to integrate a camera with an image processor. But smart cameras also have limitations. The knowledgeable user has few hardware choices. For example, if you need an image sensor with good sensitivity at a certain light frequency, or a high-resolution image sensor that delivers high frame rates, you will have difficulty finding an appropriate smart camera.
The processing power of smart cameras is also very limited, as least when compared with other alternatives. While some smart-camera manufacturers advertise high inspection rates, the full story is that these rates can only be achieved in the simplest of applications. Moreover, selecting a platform with greater processing power enables the use of better software algorithms. These better algorithms will accommodate real-world applications in which the lighting and part presentation vary. In short, a PC will usually give you more reliable results.
At BD Automation we apply smart cameras when appropriate-that is, when the application does not require a lot of horsepower, permanent image or data archiving is not needed, and the operator interface functionality provided by a PC would be overkill. In all other cases, we will use an industrial PC.
VSD: When do you recommend that a vision system include an operator interface?
Durand: We recommend operator interfaces for nearly all vision installations. Without an operator interface, a maintenance technician must be called to troubleshoot the simplest of issues, creating unnecessary downtime. The addition of a new product type, or the redesign of an existing type, would require a highly trained technician to reprogram the system. On the other hand, a well-designed user interface can reduce down time and expedite setup of new product types.
VSD: How do you envision the future of imaging in the industries you serve?
Durand: BD Automation primarily serves FDA-regulated manufacturers. These companies are truly focused on delivering the best possible products to their customers. With this in mind, the future looks bright for machine vision. We see inspection, verification, and robot-guidance systems being more deeply embedded in all manufacturing processes. Industry standards for data exchange continue to evolve, lowering hardware and integration costs. Lighting technology is catching up, though we still need better packaging for industrial environments. The general-purpose vision system will become less common as task-specific appliances are developed and adopted. Systems will continue to become easier to use even as performance expectations rise.