Vision & Sensors - USB 3.0
The Interface of Steel
It’s a bird, it’s a plane, it’s “Superspeed”
July 8, 2013
USB 3.0 technology, which represents the second significant revision of the Universal Serial Bus standard for computer connectivity, is 10 times faster than the USB 2.0 iteration, as it has transmission speeds as high as five gigabits. It’s also five times faster than the popular Gigabit Ethernet (GigE) interface. That’s why it is also called “Superspeed.”
And that’s also why it has also generated great enthusiasm. Look at USB 3.0 camera technology: It represents a versatile digital solution that serves a broad range of customers, as it’s applicable to a range of needs.
For instance, as it combines speed with optimal resolution and sensitivity, the technology supports the transportation sector, providing advanced surveillance for vehicles that pass through toll booths. High-speed cameras are required to capture images of cars and trucks. USB 3.0 provides the required speed.
But capabilities are applicable in other areas, such as the medical arena and the entertainment sector. In life science applications, this sophisticated piece of equipment proves valuable in pathology and live-cell imaging, as well as gait analysis (a systematic study used to assess, plan and treat patients’ locomotive problems). The USB 3.0 CMOSIS senor-based camera supports technology designed for high-speed streaming video and image capture, with optimal resolution. This recently introduced technology will have considerable impact on diagnosis.
In the entertainment area, the technology provides lifelike imagery for the creation of gaming and movie product. It vividly recreates movement of human forms, which makes the video game experience much more realistic. Further, the technology, when used in movie animation, imbues images with a degree of visual verisimilitude that astonishes. With this advancement, cartoons are no longer just schematic drawings; character movements are as realistic as possible.
That points to another—and more practical—purpose: crash testing. Indeed, the visual capabilities offered can help saves lives.
All of this addresses the challenges once faced by users of machine vision systems. System efficiency is the end goal, as it translates into higher productivity levels. Bringing the technology further down into the weeds—that is, the factory floor—the technology’s increased speed directly connects to increased profit.
Indeed, USB 3.0 offers considerable performance improvements over the previous iteration: USB 2.0, one of the most widely used data interfaces. Development came in response to demand for higher speed and higher bandwidth. With its increased bandwith, USB 3.0 uses two unidirectional data paths: one receives, the other transmits. The most immediate—for sure, the most apparent— advantage relates the high data transfer capability. USB 3.0 also offers better power management and improved bus utilization.
Greater efficiency correlates to the higher speeds of imaging systems. Machine vision tasks require high-quality, high-resolution images and more compact systems, but faster imaging speed was the need most expressed. On the factory floor, machine vision increased product quality and company output, as it delegated repetitive inspection tasks to computer-based systems. However, the benefits found application in many other areas. “For instance, transportation has unique challenges,” says Dany Longval, director of product management for Lumenera Corporation, which is actively involved in producing USB technology. “Machine vision systems faced uncontrolled lighting conditions and have tight physical restraints, operating over a wide range of condition.”
Hence, the need for more sophisticated—and faster—technology: Longval looks at specific benefits of USB 3.0 (compared to machine vision):
- Transfer – the higher speed and higher bandwidth particularly serves the users who work with very large files. Items such as movies or huge collections of high-resolution images (such as you find in the medical arena) require need the high bandwidth required to accomplish fast data transfers for enormous files. “Integrators looking to build a high speed, high-resolution machine vision system can also benefit from this technology,” relates Longval. Indeed, several industrial cameras manufacturers acknowledged this trend and have already developed or will soon release USB 3.0-based camera product lines to address new needs. In addition unlike similar technology (i.e., Camera Link or CoaXPress) USB 3.0 needs no special interface cards or frame grabber in the host computer, Longval points out.
- Increased efficiency – The USB 3.0 protocol enables more efficient, resource-friendly data transmission, Longval indicates. Here’s one way how that works: Via Direct Memory Access (DMA), USB 3.0 host controllers can retrieve image data from USB camera with minimal CPU involvement. This reduces computer loading and frees up resources for critical algorithm processing, according to Longval.
- Power management – USB 3.0 offers a device that boasts 4.5 watts of power (about twice that of USB 2.0). This increase is coupled with more efficient power management techniques – for example, the elimination of the power-wasting polling mechanism. “USB 3.0 has enough power to drive most machine vision cameras right off of the USB port power,” reveals Longval.
- Support of technology – USB 3.0 technology is supported by most new computers and is transferring into embedded machines, observes Longval. “USB 3.0 support is now native in the newest chipsets from Intel and AMD,” he says, adding that, in the next two years, it is expected that all computers will support the technology. More specifically, in operating system terms, Windows 8 will provide native support, while computer manufacturers are currently providing their own USB 3.0 drivers for their Windows 7-based computers. The specification can now even be found on some Mac and Linux systems. “That offers a wide choice of options to the system designer,” Longval points out.
- Ubiquitous technology – Certainly, USB 3.0 isn’t esoteric. As Longval also points out, the ubiquity, or the omnipresence, of USB 3.0 means that this standard is mature, solid and reliable – providing access to a wide-ranging section of computer devices.
As Longval indicates, it didn’t take long for the machine vision industry to embrace USB 3.0. Following acceptance, the industry went another step beyond: developing a “machine vision specific” standardized framework for the transfer of those high-speed images and videos, as well as the related camera controls.
“USB3 Vision is similar to the popular GigE Vision standard used over Gigabit Ethernet [GigE] cameras,” he says.
USB3 Vision, he continues, relies on the GenICam programming interface to model cameras and their controls. Its standard enables interoperability of cameras, accessories, and software from different manufacturers, and componentry provides plug-and-play compatibility. Interchangeability has almost no effect on the overall system, he says.
The Future is Now
USB 3.0 pushes the envelope of what can be achieved with a machine vision system, he succinctly states.
The specification delivers a high-speed data interface with the ease of use of a consumer-oriented technology. The USB 3.0 setup eliminates specialized frame grabbers, exotic cabling, or tedious software installation.
By providing higher speed, plug-and-play operations, and high device power, USB 3.0 effectively enables new applications while making vision systems better and cheaper. Many of these applications are on the factory floors, including automated optical inspection of semiconductors and electronics, and more exist outside of the factory floor like transportation or medical instrumentation.
When looking at other digital interfaces, it’s apparent that USB 3.0 resides at the intersection of high data rate and power/data transmission over a single cable. Further, the technology is not just cost-efficient but easy to use. Gone are frame grabbers, overly complex cabling, and too-complex software installation.
Looking ahead, USB 3.0 represents potential for more new applications in machine and computer vision – and in whatever market it is deployed in. Expect to see broad embracement, as the previous iteration (USB 2.0) has enjoyed widespread acceptance.
USB 3.0, industry observers say, should expand the parameters of what is possible with a machine vision system – via higher speed, plug-and-play capabilities and increased power. Users in the transportation, medical, commercial and industrial sectors stand to benefit.
For more information, please visit www.lumenera.com