INSUBCONTINENT EXCLUSIVE:
Performance Motion Devices’ N-series motion controller-drives help the Dusty AMR avoid obstacles, ledges, and other dangers
| Source: Dusty RoboticsThe construction industry is under pressure
Labor shortages, rising material costs, and demand for speed and precision are pushing builders to seek automated solutions that boost
efficiency, safety, and sustainability
Dusty Robotics hopes to use its technology to change this.In most cases, plans are marked in physical spaces using old-fashioned means:
Depending on the site, personnel might use a total station (a surveying instrument integrating several measurement tools) or perhaps just
tape measures and chalk lines to mark where things go
The approach largely unchanged from those used centuries ago.Huge stacks of blueprint hard copies detailing each floor and system are slowly
yielding to digital communications, but information is still manually communicated onsite, explained Mike Thompson, principal engineer at
So too often, a building’s 3D model isn’t what gets built
As various trades lay out their plans, mistakes and outdated information often lead to incorrect layouts, rework, and delays.Dusty Robotics
designs the FieldPrinter 2The ION/CME N-series motion-control drive imparts the Dusty design with the control needed for precise automated
| Source: Performance Motion DevicesMountain View, Calif.-based startup Dusty Robotics has designed an autonomous mobile robot (AMR) called
the FieldPrinter 2 to independently map and mark 3D building designs onto 2D construction floors with 0.0625-in
With it, construction teams no longer have to constantly check their laptops, iPads, and paper plans to know what must be built and
where.Core to the AMR’s function are two off-the-shelf motion control components from Performance Motion Devices (PMD)
The ION/CME N-series drives provide control and power for the AMR’s two front wheels, and more specifically, the two brushless DC electric
motors (BLDCs) driving the wheels
The AMR’s rear wheel has no active drive.The controller drives position the robot, along with a suite of onboard sensors that provide
precise location information, including trackers, encoders, and inertial measurement unit gyroscopes.“We want continuous motion between
all the objects that we print,” said Ryan Dimick, controls engineer at Dusty Robotics
The system must allow for constant profile changes as the robot switches between navigating and printing.”In fact, the new FieldPrinter 2
AMR improves on a previous iteration with the help of the PMD controller-drives
The first iteration’s use of another vendor’s motion controllers created challenges for the startup‘s developers, including an
inability to understand and rectify errors without workarounds
The new controller-drive solution addresses these issues and fits into the existing platform.More specifically, the PCB-mountable
single-axis controller imparts high-performance motion control, network connectivity, and amplification for an all-in-one drive with a
So, the robot can download and run code
Plus, the controller-drives give Dusty Robotics visibility and customizability.“When we ran into an issue, it was always something we
“We overcame any latencies we had in the past and really set our own timing characteristics for the motors and motor control.”For
example, Dusty wanted to be able to modify the control loop and field-oriented control loop parameters, he added.“[Dimick] is constantly
pulling data into spreadsheets, graphing it, and looking at all the inputs and outputs to the motor controller — and understanding what
small tweaks we need,” Thompson explained
“That ability to bring graphs into alignment with his expectations — that was a big challenge before.”Dimick added, “We’re working
on a millisecond-level time scale
Getting information very quickly is important for all the tuning and high-level controls, and we were not able to reach that prior to
PMD.”PMD’s ION/CME N-series motion control drive is instrumental to the robot’s position accuracy
PMD’s N-series drives also give the engineers access to internal control parameters to customize and troubleshoot the design
| Source: Dusty RoboticsPMD helps Dusty solve edge casesDusty Robotics closely collaborated with the controller-drive supplier to resolve
“Anytime I was integrating the controller into the product and had questions, they were quick to jump on a call, and they even released a
custom debug version for me to temporarily use for diagnosing an issue,” said Dimick.This collaboration also informed the AMR
manufacturer’s industrial-communication choice.The controller drive supports communication via Ethernet, CAN, RS-232, RS-485, and serial
Dusty wanted certain communications coming in a slightly later version of the controller-drive.“So, we waited, and I think we were one of
the first to really use it,” he recalled
“Then we helped [the supplier] debug the firmware, and they quickly returned new versions for us to use.”A black diagram of the PMD
| Source: Performance Motion DevicesThe Dusty FieldPrinter 2 has a laser tracker that continuously reports AMR position — but often the
tracker doesn’t have a view of the robot, so operation is blind
But the controller-drive (in conjunction with the robot’s sensors) keeps the AMR on track.“When the robot is printing within a blind
spot, not visible to the tracker, it’s relying on the inertial measurement unit and encoders that are coming through the controller
It’s relying on all the other sensors for five, 10, 15 seconds of continuous printing,” Thompson explained
“Then, when it comes out of the blind spot, it tells the tracker exactly where it is
We need to give that tracker the accuracy so it can very quickly and precisely acquire the signal.”Here, sub-millisecond timing precision
helps the AMR handle blind spots so common at cluttered jobsites
“That information and smooth predictable motion lets the AMR accurately estimate its location and continue printing without line-of-sight
to the laser tracker,” said Dimick
This blind-spot printing is the biggest improvement of the new AMR version.The controller-drive can also apply an electronic brake to the
A bit of Dusty’s own software, running on one of the controller’s chips, serves as a watchdog
If it loses communication to the robot, it powers down the motors.As the company name implies, Dusty Robotics’ system must operate in
dirty environments and in all kinds of weather — in the Arizona sun, as well as the 14th floor of a Chicago building under construction
when it’s -20° F — and with unknown obstacles and spotty Internet connectivity.Unlike competing solutions that leave sensitive
electronics exposed, PMD said the controller-drive used in the FieldPrinter 2 comes standard with an enclosed package to protect internal
Future iterations of the robot could see higher levels of integration.“PMD provides a pathway for us,” Thompson said
“They provide the controllers themselves and can open their controllers and give us access to the independent parts to let us create a
highly integrated solution.”“It’s something that we haven’t really pursued but lets us preserve the investment that the engineers
have made … and still make the system faster and lighter than it is today,” he added.About the authorChuck Lewin is the founder and CEO
of Performance Motion Devices
Launched in 1992, PMD is headquartered near Boston
It is a developer of motion control technology for life sciences, robotics, and industrial automation
PMD delivers a broad range of advanced electronic motion control products, including integrated circuits, digital amplifiers, digital
drives, and boards to a worldwide customer base.Editor’s note: This article was syndicated from The Robot Report sibling site, Motion
Control Tips. Save now with early bird discountThe post Dusty Robotics designs FieldPrinter 2 robot with PMD motion controllers appeared
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