vendor organizations have announced the release of the energy profile
specification for SERCOS III. The goal of the Energy Profile is to use
intelligent control algorithms and Ethernet networking to monitor and manage
energy usage on automated machines.
are already under development and will be available in 2011," says Peter Lutz, managing
director of SERCOS International.
Energy is an application layer profile that defines parameters and commands for
reducing energy consumption in a uniform vendor-independent manner. The control
reads out parameters for each SERCOS Energy component on a SERCOS III network,
receiving status information and detailed consumption values. Depending on the
situation (such as scheduled or unscheduled breaks), the control can switch
connected components such as drives, I/O and sensors into energy-saving
conditions up to a complete shut-down, considerably reducing their energy
consumption. †††††† †
is already doing work on an energy profiler for its MTX series of CNCs.† The software looks at the energy consumption
of a given cycle, and then comes back with recommendations on how to alter the
cycle.† With or without that energy
analysis, it can selectively reduce energy usage or shut down completely the
energy consumption of devices on a machine.
of that functionality requires pieces of the SERCOS Energy Profile standard to
get information from peripheral devices on the energy they are consuming, and
to selectively control energy consumption," says Scott Hibbard, vice president
of technology for Bosch-Rexroth. "With a pump, for example, you may not want to
put current sensors on every pump. But you may be able to embed information in
the pump on the energy required to get up-to-speed, energy usage to pump or
recycle coolant, and energy used to start or stop operation."
says that data available to the control system will allow it to intelligently
determine if the pump is required and if it is possible to shut down or idle
pump operation for a specific timeframe. To control the peripherals on-the-fly,
the system needs information on energy consumption under full load, idle mode
and the energy required to both get up to speed and stop the device. With that
information, the control system can do its calculations, and then also be able to
command the device to run at full speed, shut down or go into a low power
consumption mode to optimize energy usage.
the end, the goal is to manufacture parts with the least amount of cost and
energy usage as possible, and still be productive which is a third variable in
the equation," says Hibbard. "There is a need to find out the total amount of
production and the piece cost in energy for each of the components
using function blocks in our controls, we estimate how much energy a coolant,
lube or hydraulic pump consumes in terms of energy. We have very accurate data
from the drives because we have used existing IDENTS or sets of parameters that
we will be able to switch over later to the Energy Profile," he adds.
developed at this point require participation by the end user to analyze and
intelligently look at the machine cycle. Often there are decisions on whether,
for example, making a part faster will actually consume less energy per part. Often
energy consumption is reduced by upping the productivity of the machine,
especially on metal cutting machines with significant energy usage during the
idle periods. But the quick win is to not allow these machines to idle for too
long: either make parts or completely shut down the machine.
says the standard is written so that the peripherals don't require a high level
of intelligence. The ideal for the main control software is that every device has
current or voltage measurement capabilities, and power calculation capabilities
available on-the-fly. But he acknowledges that is probably unrealistic on very small
pumps, for example.
testing, a manufacturer can know what each device consumes in terms of energy. If
manufacturers test each component and provide average consumption data while
running or idling and embed that into the device itself, the intelligence
required in the device is limited. The idea is that devices with memory would
be hooked to a SERCOS network which would find devices active on the network
and determine if they support the Energy Profile.
work is being done on perfecting the software at the control level, there is a
limited amount of data available from the peripherals. The more devices that
come online that can provide data, the more accurate assessment that can be
made on the machine's energy consumption and energy used to produce a given
we know the energy consumption of SERCOS drives while they are operating or
idling," says Hibbard. "With hydraulic pumps which we manufacture, we can measure
or make accurate estimates as well. But for other devices, it is uncertain
whether we can derive any meaningful information from them or not, and often
can't exploit any type of idle capabilities and don't have an accurate or automated
way to assess energy usage," he adds. "But we want to get to a point where a
machine builder or packaging company looks for devices that conform to the
SERCOS Energy Profile. The controller software would detect these devices on
the machine, and use the energy usage data to make more intelligent decisions
on machine operation.
that point, there is less work for the machine builder to optimize the energy
consumption of the machine."
discrete manufacturing, there is a significant opportunity to save by limiting
energy usage during idle time. As much as 20-25 percent of the total power
consumption on discrete manufacturing machines occurs during idle time. That time
is not just limited to sitting and waiting for parts, but also during part
transfers and waiting for tooling changes.
continuous process machines, there is not as much of an opportunity because
they are typically running 24/7. But there are opportunities to line-up and
level off energy consumption by seeing what the energy consumption is for the
various devices and making recommendations to optimize efficiency.
8-page whitepaper describing SERCOS Energy can be downloaded from http://www.sercos.com/literature/pdf/SERCOS_Energy_Whitepaper_V10.pdf