To compete on a global scale and meet the growing
demands for increased throughput, higher
quality, and greater yield, the way the machine
industry builds machines has evolved. The
industry is enhancing purely mechanical systems, based on
gears and cams, with electromechanical systems, which combine
mechanical elements with advanced technologies such as
electronic controls and motor drives into a single system.
These software-controlled electromechanical machines
offer better accuracy and flexibility for increased throughput
and yield. They also increase energy efficiency, resulting in both
environmental and economical benefits. Yet electromechanical
machines are difficult to design and manufacture.
Today’s designers must be familiar with a number of application
areas and development tools, including mechanical design,
embedded hardware, and software development. Meeting this
multidisciplinary challenge requires improved development
techniques, design tools, and embedded control technology.
Multiple Hardware Platforms Required
There are three traditional platforms used for embedded
machine control: programmable logic controllers (PLCs), single-
board computers (SBCs), and custom-designed hardware.
Each of these platforms has unique strengths and weaknesses.
PLCs, for instance, are extremely rugged and reliable. They
are programmed with an industry standard, are great for digital
I/O, and have first-class connectivity to industrial networks,
making it easy to connect to a variety of devices, such as motor
drives. On the other hand, PLCs are unable to perform highspeed
control and measurements, they don’t have very flexible
software, and they’re a closed platform.
SBCs, which use a PC architecture and come in a variety of
sizes and options, have the benefit of a large ecosystem with an
extensive selection of products, such as I/O, that can be made
to work with them. On the downside, these complementary
products do not work out of the box and often require a significant
integration effort. In addition, SBCs aren’t very packaged
and often require custom enclosures.
Custom-designed hardware is a great option for applications
requiring complete control over cost of goods or form factor.
Designers use only the components that are necessary for
the machine, optimizing performance and deployment costs.
Unfortunately, custom hardware requires significant development
time and resources for board bring-up. They also are
much harder to maintain due to component ends-of-life.
Programmable automation controllers (PACs) combine the
reliability and ruggedness of PLCs with the processing power
and flexibility of PCs to provide a single platform that is optimized
for machine control, monitoring, and logging. In addition,
some PACs include programmable FPGAs, so machine
builders benefit from custom hardware performance without
having to build custom hardware.
By combining the strengths of all three traditional machine
control platforms, PACs give machine designers a single-box
solution for their complex machines, saving time and money
on hardware development and integration.
Large Development Teams
As today’s machines become more complex, the development
teams that design and build them are required to do more
and know additional, disjointed design tools. With budget
pressures, increasing the pool of engineers that work on the
machine is not always an option.
The emergence of system-level development tools has
allowed domain experts to perform tasks, such as programming
an FPGA, that have typically required a hardware design engineer
to complete. By abstracting the low-level implementation
details and providing a common environment to develop all
aspects of machine design, development teams can accomplish
more with significantly fewer people and in less time.
Considering the various facets of embedded machine design,
the domain expert traditionally develops the user interface,
application algorithms, and hardware-based custom sensors
and transducers. This leaves low-level tasks, such as developing
drivers for operating systems, incorporating I/O hardware, and
implementing buses to share data between multiple embedded
systems, to the career embedded engineers.
With a system-level tool, however, the low-level tasks traditionally
performed by career embedded engineers are abstracted
and automated by high-level tools. Using software design
tools that are tightly integrated with hardware platforms,
incorporating real-time operating systems and I/O capabilities,
domain experts can complete embedded machine designs
without relying on specialized engineers, facilitating greater
output with fewer people.
Graphical system design is an example of a system-level tool
that is increasing productivity by providing the necessary
approach and tools to expand the pool of engineers and scientists
capable of embedded machine design. By standardizing on
a single tool that spans so many application areas and hardware
platforms, machine builders can focus on application development
rather than spending valuable time on low-level programming
and learning multiple development tools.