The birth of modern vision industry happened during the 90s computer boom . With personal computer becoming cheaper and faster during that era, running machine vision algorithm no longer requires expensive investment in hardware development such as DSP and FPGA. Back then machine vision related companies were mushrooming in every corner of the developed world.
The digital
evolution of industrial camera is fuelled by the ever growing appetite for higher
resolution and faster frame rate. The machine vision industry looks towards
digital interface when traditional analogue standards can no longer coped with
the increasing demand.
During that period, with
no single standard digital format, interoperability was near impossible. In October 2000, the very first digital standard known as Camera Link was
introduced. It was, and still is, an expensive technology, but semiconductor
equipment makers embraced it quickly as the need for quality inspection technologies
exceed the cost it incurred. Unnoticeable by some, the Camera Link standard has
actually fired off the first servo in the race for dominance in the digital age
of modern machine vision .
Within a year
after the induction of Camera Link, Pointgrey and AVT pioneered the firewire
standard (1394A) developing range of successful low cost digital format cameras
for the industry. The salient of this new technological front are AVT’s Dolphin
series and Pointgrey’s Firefly series. Almost immediately, these cameras enter the
industry like a welcoming storm from a long drought, shaking up the mainstream
and low end machine market. Applications that require higher resolution and yet
at a lower speed now have an alternative solution, Firewire instead of Camera Link.
With the success of Firewire, industry innovators are now in two camps. With one
camp tirelessly looking into high end dedicated imaging interfaces (deriving
today HS-link and Coaxpress standard), predicting that this is the future industry
needs. While the other believes that there
should be a low cost solution and ploughs ahead with commercial standards.
In 2006,
the GigE Vision standard was inaugurated; it provided a much larger bandwidth and
at the same time eliminated the limitation of cabling distance of firewire
technology. Among the early adopters of this technology was Basler. The Basler Pilot
series with Kodak sensor together with their Scout series with Sony sensor was first
introduced in 2006. The impact of GigE Vision became apparent when Basler launches
her Ace product near the end of 2009. Its success lies not only in her
indigenous design but also the strategic alliances with major industry partners
such as National Instruments and Cognex .
Today, USB3
Vision emerged as the new mainstream digital standard. Unlike its predecessors
(GigE Vision and Firewire), USB3 Vision is more than a replacement technology
for the earlier mainstream market. It has the great potential to penetrate into
the untouchable high end area scan market that had been continuously dominated
by Camera Link technology for the last 10 years.
Camera Link
Base interfaces with a bandwidth of 255Mbyte/sec makes up the major demand for area
scan Camera Link market. USB3 Vision with its 400Mbyte/sec bandwidth provides a
competitive alternative to Camera Link Base. There is one major drawback in
earlier technology such as GigE or Firewire, CPU loading for camera acquisition
gets significant with increasing amount of data steamed to PC. USB3 is different
from such earlier consumer technology, thanks to the use of DMA (Direct Memory
Access), CPU loading becomes negligible.
Camera Link Base
|
Firewire
|
GigE Vision
|
USB3 Vision
|
|
Bandwidth
|
255MB/s
|
80MB/s
|
100MB/s
|
400MB/s
|
CPU Loading
|
Low
|
High
|
High
|
low
|
Triggering Concurrency on multiple cameras
|
High
|
Low*
|
Low
|
Low
|
Most OEM equipment
makers are now keeping a keen eye on this technology and are seeking for the perfect
moment to adopt the change. In 2 to 3 years time, the proliferation of USB 3.0
hardware on PC will become prevalence and in tandem, development in the consumers
industry is working towards an overwhelming bandwidth of 10GB/s with USB 3.5. Already
a Taiwanese chip maker, ASMedia, has planned to release her first USB 3.5 host
controller by 2014. There are definitely plenty of rooms for improvement in the
USB vision technology. A whole new world will emerge for machine vision as the
evolution of USB technology in the consumer industry continues to advance. It
is indeed an exciting time for the future of the industry.