[Technology Report]
Tools Make Motion-Control Design A Snap
Motion control may seem like a mechanical problem, but new software moves it further into the digital realm.
Mat Dirjish
ED Online ID #19757
October 2, 2008
Copyright © 2006 Penton Media, Inc., All rights reserved. Printing of this document is for personal use only.
Reprints
One of the most challenging
and widespanning
areas of
design work involves
motors and motion
control. Choosing
the right motor and
related control circuitry
is one thing. Getting it all to fit into the end
product and work accurately is another. And, as with
any mechanical component, the opportunities for
error are many. Fortunately, motor makers offer users
many powerful tools to take the vinegar out of their
design chores. More often than not, these tools are
available at no extra charge.
Design, Analyze, and Optimize
When it comes to design tools, particularly software,
nothing instills confidence like versatility and
longevity. One example is the Pro-
Motion motion-control software from
Performance Motion Devices, which
takes users through a complete cycle
from design to analysis and through
optimization. Available for several
years now, it’s constantly evolving to
accommodate the repetitive and tedious
tasks motion designers must perform.
“Motion design requires phases of
configuration, setup, testing, and modification
that require repetitive iterations
and tuning to optimize a motion
system,” says Chuck Lewin, president
and CEO of Performance Motion
Devices. “Pro-Motion is designed specifically
with that need in mind and
will continue to advance to meet future
requirements.”
Retaining its initial attributes, the
easy-to-use Windows-based application
accelerates motion-system development.
It includes an axis wizard for
configuring and testing motion architectures, as well
as an auto-tuning feature for both current and position
looping of servo motors.
The software also allows the creation and saving
of separate projects. Recent enhancements include
multiple and simultaneous connectivity to a variety
of controllers, a multidrop over serial networks and
controller-area networks (CANs), and oscilloscope
tracing of motion parameters (Fig. 1).
Overall, the Pro-Motion software is a prototyping
tool for developing motion-processor-based
systems using one of the company’s Magellan
processors, Prodigy motion card, and/or ION digital
drives. Of note, its instruction sets don’t dictate
motor type. Users are free to mix dc-brush, dcbrushless,
and stepper motors within multi-axis
configurations. And speaking of “free,” Pro-Motion
comes with Magellan-based developer’s kits at no
extra charge. A user manual is available online at
www.motion-control.pmdcorp.com/downloads/Pro-Motion_Users_Guide.pdf.
Need Speed?
The unique approach taken by Motion Console
software from Intuitive Motion Systems promises to
reduce software-development times in motion-system
automation apps. Enlisting a design philosophy not
based on electronics and protocols, users can expect
to configure and define their motion systems and
operation parameters in several minutes. Currently,
the application supports Faulhaber MCDC 3006S,
3003S, 2805, and NAI MCCQ dc-motor controllers,
with Galil support appearing in the near future.
The Motion Console architecture quickly integrates
a motion controller and drive electronics,
communication hardware, motors, stages, cameras,
and human-machine interface (HMI) devices. It
provides a spreadsheet interface for entering, calculating,
and storing motion parameters,
which users can copy and paste from an
Excel file (Fig. 2).
Axes can represent velocities rather
than positions via formatting. Buttons in
the user interface and on a wireless or
wired control pad initiate storage of a system’s
current position in the spreadsheet.
Run buttons, also within the interface and
on the control pad, initiate execution of
motion sequences defined in the spreadsheet.
Extra columns are on tap for annotation,
execution flow control, pauses, and
timed delays.
For system scaling, a configuration
window lets designers enter a value for
displacement per encoder count or by
computing this value in the application’s
resolution calculator. Radio buttons and
drop-down boxes enable hardware assignment
and serial port selection, respectively.
A video interface connects to DirectShow
and DCAM-compatible cameras.
The software also can write data to, and retrieve data from, any serial
device and store it in the spreadsheet. It offers port configuration and message
formatting capabilities, as well as automatic backlash compensation,
enabled after position-mode moves, velocity-mode jogs, or both. The company
can modify Motion Console for use with most motion-controller types
at no charge. For a free test spin, visit www.imotionsys.com/free_trial.htm.
Taking a Different Route
Providing an ActiveX programming environment for the company’s
XMP motion controllers, the MPX software from Motion Engineering,
now a part of Danaher Motion, offers an alternative way of accomplishing
motion and I/O tasks. Eliminating the need for C/C++ programming, users
can create custom motion interfaces with LabVIEW, VisualBasic, Excel,
VBScript, and other applications supporting ActiveX controls.
Including motion-application development, the tool is also viable for
developing test and production applications plus specialized utilities. It
includes ActiveX controls, device drivers, documentation, sample projects,
and MotionConsole and MotionScope, the company’s Windows utilities.
In addition to allowing users to perform their programming tasks in any
environment that supports both ActiveX controls and SynqNet controllers,
central features of the application include support for up to 32 axes of
motion; support for both servo motors and stepper motors; operation across
TCP/IP networks; a data recorder; scale interpolation; position capture;
on-the-fly trajectory modification; CANOpen support; quadrature encoders
and SSI encoders; drive feedback; and point-to-point, trapezoidal, S-curve,
S-curve jerk, velocity, velocity-jerk, and coordinated motions.
In the near future, the company will be adding several enhancements that
will include compare outputs, SynqNet I/O, and analog-to-digital converter
(ADC) inputs. Naturally, there will be upgrades and accommodations supporting
new developments and designer demands. For a complete MPX
datasheet, visit www.motioneng.com/pdf/MEI_MPX.pdf.
More Enhanced Motion Tools
Recently, ACS Motion Control extended the capabilities of its application
development kit, the ADK 6.0, by adding support for the IEC61131-3
programming language. Users can now program using any of the five
languages in addition to ACSPL+. The software’s fully variable mapping
enables bidirectional interfacing, mutual synchronization, and functionality
exchanges between ACSPL+ and IEC 61131-3 programs.
The upgrade’s full CANOpen support now allows for the configuration
of SPiiPlus motion controllers as a CANOpen master, according to
the DS-402 specification. Other features include advanced two-phase step
motor operation in both open- and closed-loop modes when using the internal
amplifiers in the SPiiPlus CM and MC4U controllers and support for a
second TCP/IP Ethernet port on all MC4U components.
Noting that Motor Industry Software Reliability Association (MISRA)
standards are seeping into software projects falling outside the requirements
and definitions of the automotive industry, LDRA Technology’s motor/
motion tool suite now includes capabilities for compliance with the emerging
MISRA-C++:2008 standard.
Already within the scope of the C++ language, LDRA has worked
together with Lockheed Martin to develop the JSF AV C++ coding standard.
Additionally, the company has been very active in enforcing the
high-integrity C++ coding standard and the LM Train Control Program
(LMTCP) standard.
Said to be highly anticipated in the industry, MISRA-C++:2008 is the
newest coding standard to be published by MISRA and is expected to be
adopted across the software industry. Compliance with the standard further
complements the LRDA suite’s existing support for MISRA-C:1998 and
MISRA-C:2004, HIS (Herstellerinitiative Software), and GJB (Chinese
Military Standard) standards for the C programming language.
Assuming widespread acceptance of MISRA-C as the industry’s bestpractice
solution, LRDA Technology foresees escalating adoption of
numerous safety-related and safety-critical software-development projects
and applications in a wide variety of other industries, including the rail,
aerospace, military, and medical sectors.
For further information on MISRA-C++:2008 compliance and
related issues, visit www.ldra.com/downloads/MISRA-CPP_2008_Standard_050608_UK.pdf and http://www.ldra.com/misracpp.asp.
|