Twin vise for Industry 4.0; Motion control for robots, drives, motors.

Geisel Software, a Massachusetts-based custom software development firm, is partnering with North Carolina-based Fayetteville State University (NCFSU) to perform research funded by NASA’s Minority University Research and Education Project (MUREP) Space Technology Artemis Research (M-STAR) grant. It will fund active and on-demand multi robot perception (AOMRP) research to develop multi-robot perception, a technology that uses highly specialized image sensors to support NASA’s use of autonomous multi-robot systems for scouting missions on the moon or other planets.

“Partnering with Fayetteville State is a natural fit,” comments Brian Geisel, Geisel Software CEO. “We both bring strong backgrounds in computer science and software with an especially strong focus on robotics. Our unique background in ground-based robotics, swarming robotics, mobility, and sensors adds experience from both DOD and commercial companies that are advancing the state of the art.”

Dr. Sambit Bhattacharya, professor of computer science in the Department of Mathematics and Computer Science at NCFSU and his team will work with Geisel Software engineers to develop technologies that provide situational awareness for exploration robots, human-assistive robots, and autonomous spacecraft.

The fully automated compact PTP/PTH series twin vise provides pneumatic and hydraulic clamping force with standard jaw stroke, long stroke, or one fixed jaw stroke control.

Ideal for automation, the self-centering PTP pneumatic and PTH hydraulic twin vises are for tombstone and storage solutions as well as 4- and 5-axis multi-pallet machining centers with or without robot loading.

The twin vises feature a compact design, failsafe clamping force up to 60kN, and case hardened components for high precision and long life. Suitable for O.D. and I.D. clamping, the spring-loaded twin vises can be used with industry standard or engineered top jaws. A series of solid carbide serrated inserts grip the workpiece securely, minimizing vibration, allowing for higher cutting speed and feed rates, meaning more metal removed in less machining time.

Supporting up to 64 interpolated axes, the softMC 703 compact controller delivers high-performance motion control capabilities to robots, drives, and motors via any major original equipment manufacturer (OEM) programmable logic controller (PLC).

When used with the stepIM integrated closed loop stepper, CDHD2 servo drive, and PRHD2 servo motor, the softMC 703 controller creates a complete and cost-effective motion control solution for dynamic applications in industrial automation.

The softMC 703 controller provides Industry 4.0 machine-to-machine communication while reducing overall cost of motion control system design and configuration. Extensive programming options allow designers to create flexible motion programs with support for preemptive multitasking and asynchronous event response. The softMC 703 includes an open, real-time programming language, C/C++, and the robot operating system (ROS). The controller also features ControlStudio, an integrated program development environment.

Drive System Design’s open platform inverter may be a key component for future electric aircraft enabling quick and efficient development of motor control systems.

A key component for electrified, fuel-efficient aircraft is motor control technology to increase efficiency and decrease dependency on carbon-based fuels.

Drive System Design (DSD), a company specializing in the rapid engineering and development of electrified propulsion systems and associated technologies, is demonstrating a new solution that places these capabilities within reach. The company’s open platform inverter enables quick and efficient development of motor control systems from initial concept to first prototype. Users gain access to every aspect of the inverter, including the hardware, drivers, and software.

The inverter solution also features reliable and customizable hardware paired with a flexible, modular plug-and-play software for aerospace, automotive, commercial vehicle, defense, and marine industries.

“We’ve found that aerospace has picked up the baton from automotive in pushing motor speeds and getting power density in this way. Defense is the big catalyst for many power distribution and generation considerations,” says Ben Chiswick, DSD’s director of engineering and business development.

Chiswick explains the inverter initially was developed to support and lower the risk of prototype motor testing. While it was in development, the company realized it would be a good enabler for a broader range of customers. As more companies approached DSD to engage in electronics design and development projects, they realized they had a good building block to support other industries, such as aerospace and defense. The inverter’s DNA can be designed to meet customers’ specific needs and is woven through their products.

“We’re having conversations with electric vertical take-off and landing (eVTOL) companies, often startups or conventional take-off and landing (CTOL) for ground testing,” Chiswick says. “We can get them through their initial tests. There’s no flight certification needed and it’s helping get people up and running.”

“As we see the emergence of not only strong market players in eVTOL and eCTOL, the next step is electrified propulsion on a larger scale for aerospace, with higher altitude requirements driving a lot of the certification difficulties that must be faced,” Chiswick explains.

While the team designs the open platform inverter to be a speed enabler and risk mitigator, its core is used to support customers with their own inverter development efforts.

The inverter also plays a critical role in meeting efficiency and mass requirements for aircraft. In development, the two important factors to consider are the core inverter technology being used [insulated-gate bipolar transistor (IGBT) power module or silicon carbide] and the inverter’s role in the complete system’s thermal management. The core inverter technology drives improved efficiency – enabling higher motor speeds and power densities. For relatively low motor speeds near 12,000rpm, IGBT technology is perfectly suitable. However, going at faster rates (20,000rpm and possibly 30,000rpm) the switching frequencies get so high that IGBT just dissipates heat.

“We won’t see IGBT in aerospace propulsion for very long as with higher switching frequencies needed to support higher motor speeds, the power losses can be significant. Silicon carbide will become more common, and we can expect aerospace to increase rpm rates and be a driving force behind developments such as gallium nitride semiconductors.”

Thermal management of the inverter and overall system is key to reducing mass. If inverter losses are lower, a smaller, lighter thermal management system can be used.

Another area that DSD focuses on is reducing the number of fluid circuits in the electrified propulsion system. More users turning to oil cooling for their motors has allowed DSD to push development of fluid management tools to refine existing smoothed particle hydrodynamic (SPH) techniques. They can model where oil splash is going, which ensures they are getting to all the bearings. It also eliminates the need for a water refill glycol system.

Sharing fluids with existing systems offers advantages for reduced system complexity, fewer components, and eliminates the need for further fluid systems being carried on the aircraft. This improves mass and failure mechanisms and could ease certification processes, letting startups bring products to market faster.

As the future unveils more electric and fuel-cell powered aircraft, inverter demand will increase and play a considerable role powering critical on-board electric systems. DSD is evolving their traction inverter capability into on-board power generation and off-board power distribution systems, such as low voltage AC output inverters and DC-DC converters. Chiswick believes that to develop these systems further and increase power capabilities, the industry needs a more flexible approach. The chip shortage may force designers to be more open minded in their choice of chips or power boards. Chiswick says DSD is finding that many people have fully grasped the low voltage side of power electronics, and many suppliers offer low voltage DC converters and lower voltage AC inverters for power takeoffs for ancillary drives, which are common in defense and aerospace.

What eVTOL designers don't have is the complex knowledge that goes behind the motor inverter, which is what DSD’s open platform inverter is designed to enable.

“There are two distinct supply chains, two distinct systems right now, as everything moves toward being more closely integrated as a complete electrified propulsion system, a complete electrification network. There’ll be that crossover we must meet in the middle. This is key, as I think overall demand for those systems is only going to increase because electrification is here to stay and is continuously growing,” Chiswick concludes.

About the author: Michelle Jacobson is the assistant editor of AM&D. She can be reached at 216.393.0323 or mjacobson@gie.net

Drive System Design (DSD) is already working with a major player in the field to incorporate their open platform inverter. One of the first projects they’ve been involved with is InCEPTion consortium through the UK technical center. Integrated Flight Control, Energy Storage and Propulsion Technologies for Electric Aviation is led by Blue Bear Systems Research and will be delivered by the consortium of organizations with specialized skills and infrastructure for design, analysis, and testing. The companies are working together to develop a modular and highly integrated electric propulsion unit, which will be complete with electric motor and power electronics. The units are for manned and unmanned aerial vehicles (UAVs), vertical take-off and landing (VTOL) and conventional take-off and landing (CTOL) aircraft for up to 30 passengers.

Ben Chiswick, DSD’s director, engineering business development, finds developing a stand-alone electric propulsion system for the aircraft industry could help solve many challenges.

“Our motor and inverter will play a critical role in meeting the efficiency and mass requirements. The level of integration in the unit and the modular construction means we’ll need to work very closely with our partners to ensure the project is successful.”

The team will soon complete the detailed design and present it to consortium members to ensure that it meets all requirements. If they attain approval, they’ll proceed with prototype procurement, prototype assembly, test, and development.

To improve predictive engine maintenance, Rolls-Royce and IFS link usage data and engineering forecasts through the digital Blue Data Thread.

Ninety-eight million terabytes may seem like a lot of data, but that’s what the global fleet of commercial aircraft could generate per year by 2026, according to an Oliver Wyman MRO Survey.1 There’s now huge interest among big aviation players – original equipment manufacturers (OEMs); airlines; and maintenance, repair, and overhaul (MRO) operators – to gather data and use it with predictive maintenance and health monitoring systems.

Due to the pandemic, the commercial aviation industry is going through major disruptions and airlines, OEMs, and MROs alike must adapt business models, including capitalizing on new technologies to introduce time, resource, and cost efficiencies. Digital twins, artificial intelligence (AI), the Internet of Things (IoT), and other technologies are now key components of the new generation of predictive maintenance solutions that make business processes more agile and adaptive. These technologies gather key data insights and are paving the way for greater strides in predictive maintenance in the coming years.

Predictive maintenance isn’t new – in the 1990s, the IFS Maintenix team worked with the U.S. Navy to crunch through engine health monitoring data to model and predict engine component failure. Today, Rolls-Royce is using AI forecasting, supported by IFS, to help airline customers automatically update predicted maintenance deadlines for every life-limited component inside their engines – a key part of the Rolls-Royce Blue Data Thread strategy, a digital information thread connecting every Rolls-Royce powered aircraft, airline operation, maintenance shop, and factory. This is all part of the Rolls-Royce vision for the IntelligentEngine.

“The IntelligentEngine is a form of cyber-physical service where the physical engine, the services surrounding that digital engine, and the Rolls-Royce digital capability are indivisible,” explains Nick Ward, vice president of digital systems, Rolls-Royce “The IntelligentEngine forms a digital twin of a physical engine, with both connected by data. It’s contextually aware of its own operating conditions, the environment it’s flying in, the rest of the fleet it’s part of, and it’s consolidating that information to make smart decisions to maximize availability while minimizing maintenance costs and disruption.”

The benefits of this approach are huge in terms of aircraft availability and engine time on wing, which should translate into fewer delays and improved service. Rolls-Royce’s mission is that every Rolls-Royce powered aircraft flies on time, every time, with an availability as close as possible to 100%. This is where the confluence of predictive maintenance incentives comes together for all parties involved in flying.

“The Blue Data Thread contributes significantly to Rolls-Royce’s strategies to eliminate unplanned failures,” Ward says. “A jet engine is an incredibly complex example of high-engineering but being in-tune with the specific maintenance requirements and performance allows Rolls-Royce to accomplish feats such as powering an A330 to fly the equivalent of to the moon and back 50 times between overhauls.”

The Rolls-Royce Blue Data Thread is a two-way maneuver. The engine supplier collects data from multiple sources, such as engine health monitoring and information from airline maintenance management systems and contextual real-time engine flying condition and MRO data from Rolls-Royce engine facilities.

IFS Maintenix automated data sharing is critical for Rolls-Royce to re-life its engine parts, but also to allow airlines and Rolls-Royce to collaborate and share more information about engine status – for example, which engine parts have been switched or inspected and if any other aircraft systems have been impacted by engine behavior. The result of this two-way exchange is a more complete picture of engine performance – a higher resolution digital twin and a way to deliver digital insights to improve physical part use while in-service.

Participating airlines were confidently expecting improvements in overall engine performance and cost from the IntelligentEngine and the Blue Data Thread initiatives. However, what perhaps wasn’t anticipated was weaving new predictive maintenance results into day-to-day processes.

“A Rolls-Royce Trent engine can, on average, fly around the world more than 1,000 times between significant engine events. Through multi-variable forecasting, IFS can map the data on how an airline expects to fly a particular engine and combine it with Rolls-Royce data on expected part life to provide a very accurate predictive maintenance deadline, right down to individual part numbers,” Ward says.

“Now accurate maintenance information is presented to airlines daily and is seamlessly consumed by their maintenance scheduler. Initial anecdotal reports show huge progress to extend the life cycle of engines and components, increasing the time to first engine removal by 48%.

“When you have this level of monitoring and data exchange, it indicates step change in predictive maintenance. So many engine components and their details are being dynamically monitored that previous preventative maintenance approaches are obsolete. With this level of tracking, most failures are detected on an individual level before they are likely to occur, well before planned maintenance cycles. Rolls-Royce has extreme faith in its predictive analytics strategy with a goal of zero false predictions and 100% success rate.”

As the aviation industry moves toward a greener future, digitalization and predictive maintenance will be an important element for engineering, and both IFS and Rolls-Royce have made strong sustainability commitments as part of their long-term business planning.2 The Blue Data Thread program aligns with these priorities. Reducing maintenance interventions, part replacements, and overhauls also lessens manufacturing energy use and resources and minimizes the emissions footprint of part and engine logistics.

From a technical perspective, airlines can be up and running on the Blue Data Thread through the IFS Maintenix plug-in in as little as two months. This requires a quick technology installation followed by specifying key modelling information such as engine utilization. It’s the accessibility and sovereignty of data which can bring up potential roadblocks.

Airlines running other maintenance management systems must ensure they can extract, store, and analyze critical data profiles from their supporting software. Some that are running legacy maintenance software may not be able to provide enough data to feed their engine’s Blue Data Thread and digital twin.

Airlines may have some data security reservations about certain lines of data, such as part leasing and ownership, so IFS and Rolls-Royce have designed controls to manage the level of data lines specific for each airline.

Underpinning the bilateral transfer of data from manufacturer to airline and back again is an interface/dashboard to parse the aggregated data points. The difference between data and information is the ability to translate raw data into actionable insights and meaningful information.

Airlines face a digital imperative to make their operations more efficient, maximize engine life, and minimize delays – they need a data backbone. The Blue Data Thread provides this backbone to allow exchange of critical engine health and maintenance information and offer analytical insights to truly realize the potential of predictive maintenance – translating into daily improvements, significantly fewer unexpected failures, and maximum time on wing.

About the author: James Elliot is principal business architect for aerospace and defense, IFS. He can be reached at https://www.linkedin.com/in/james-elliott-ottawa-on.

1. https://www.oliverwyman.com/our-expertise/insights/2016/apr/mro-survey-2016.html

2. https://www.ifs.com/news-and-events/newsroom/2021/04/22/ifs-outlines-multiyear- sustainability-strategy; https://www.rolls-royce.com/sustainability/approach.aspx

Plastic materials are seeing increased use in aircraft and spacecraft to reduce weight, improve quality, and lower manufacturing and maintenance costs.

Due to the COVID-19 pandemic, aircraft interior surfaces are being cleaned and disinfected in ways that can quickly degrade traditional plastic materials. New antimicrobial and disinfectant-resistant plastics initially developed for use in hospitals are now being specified for aircraft interiors. These materials are formulated to meet the stringent flame, smoke, toxicity, and heat-release standards required for commercial aircraft.

Aerospace structures requiring high strength and stiffness have traditionally been made from metals or thermoset composites. However, these materials have some significant limitations. Metals are heavy, limiting their use for aerospace applications where light weight is desired. Thermoset composites tend to be brittle, often having poor chemical resistance. Thermoset manufacturing is labor-intensive, with most thermoset composite materials not suitable for temperatures above 100°C.

A new class of thermoplastic composites developed by Ensinger has strength and modulus (stiffness) values comparable to metals and thermosets. The technology involves continuous glass fibers or carbon fibers embedded in a thermoplastic polymer matrix, usually consisting of polyetheretherketone (PEEK) or Ultem PEI (polyetherimide). Since the matrix is made from high-performance, thermally stable plastics, these composites can be used at elevated temperatures.

Thermoplastic composites offer many advantages associated with thermoplastics including ductility, fatigue resistance, and vibration damping characteristics, as well as resistance to fuels, lubricants, and cleaning chemicals. Sheet stock made from these materials can be quickly formed into finished parts using heated metal tooling, lowering manufacturing costs.

The proliferation of unmanned aerial vehicles (UAVs), drones, and satellites that rely on RF signals to control flight operations has increased demand for highly reliable antennas. Optimum antenna function requires plastic radomes that won’t significantly attenuate RF signals at the desired frequency and throughout the device’s operating temperature range. Specialized engineering plastics with low dielectric constants and low dissipation factors as well as enhanced toughness, ultra-violet (UV) resistance, and thermoformability are becoming more widely specified for use as protective antenna radomes.

Metal-to-metal connections are often points of failure in aircraft assemblies due to inherent problems when mated metal surfaces are subjected to vibration and/or sliding wear. Increasingly, designers are specifying ductile, high-performance polyimide materials for applications such as spline couplings and the anti-rotation elements of locking fasteners to separate metal parts. Introducing the polymer element into the assembly increases service life and extends time between required maintenance cycles.

For spline connections that transmit power to various aircraft systems through connected rotating metal shafts, high-temperature couplings made from DuPont Vespel polyimide are installed between mating metal splines for smoother operation and longer life. The approach reduces spline wear when the rotating metal shafts are slightly misaligned. Ductility of the polymer allows for shaft misalignment without creating excessive stress on the metal shafts, bearings, or drive motors.

In aerospace locking fasteners, DuPont Vespel polyimide is used as a ductile locking element in a nut or a bolt to prevent unwanted rotation without damaging the mating metal fastener during assembly or disassembly for maintenance. This polymer element prevents the galling associated with all metal locking fastener designs.

For both examples, ductility and wear performance of the polymer mitigates problems associated with metal- on-metal contact.

Plastics have long been the prefered material for applications requiring electrical insulating properties. Electrical systems for modern military and civilian aircraft can be particularly challenging since – in addition to having good dielectric strength and resistance to electrical arcing – polymer insulators must be resistant to aircraft fuels and lubricants; withstand vibration, wear, and fatigue; and have outstanding flammability properties. Plastic insulators in aircraft may also have to operate throughout a broad temperature range – from extremely cold at cruising altitudes to extremely hot near jet engines.

Aircraft electrical system designers are now specifying fluoropolymers such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy alkanes (PFA) as well as high performance thermoplastics including PEEK, Ultem PEI, and DuPont Vespel for demanding aerospace electrical applications including standoff insulators, shrink tubing, and flexible wire wrap insulation.

Commercial aircraft are becoming increasingly more upscale, with interiors rivaling luxury hotel lobbies. Printed graphics have traditionally been problematic for aircraft interiors since high-traffic areas are exposed to wear and repeated cleaning that can quickly degrade printing.

Newer technologies such as Infused Imaging with KYDEX thermoplastics allow designers to create customized environments using imagery that’s in the material not on it.

There have also been significant advances in the plastic lens material used to manage and transmit light on commercial aircraft. New polymer formulations allow for high light transmission, excellent diffusion, and precise color control of LED lamps. Light management using high-performance plastics is positively impacting the aesthetics of aircraft interior spaces.

About the author: Keith Hechtel, DBA, is senior director of business development for Curbell Plastics Inc. He can be reached at 716.667.3377 x7413.

Improvements in technology now make grinding an option for finishing exotic materials and 3D-printed parts.

Aerospace parts manufacturers face numerous machining and finishing challenges, one being the introduction of new alloyed materials. To increase fuel efficiency and produce lighter planes, incorporating materials that are lighter, stronger, and can better manage heat is crucial. While these alloys have amazing characteristics, they can sometimes be difficult to process, resulting in the need for grinding expertise and the latest technologies. Without optimizing the grinding process, parts made with these new alloys may have poor surface quality, internal metallurgical damage, increased part cycle times, and higher manufacturing costs.

Another challenge is bottlenecks on the manufacturing floor. Some customers use wire electric discharge machining (EDM) to carve profiles and shapes into various aerospace components. While EDM is effective for parts with faces that are tough to access, grinding may be a better option for many operations. Wire EDM machining is initially less expensive than grinding, however, using EDM can take a long time to complete a part. Grinding is much faster in removing material, and while it may be more expensive upfront, the benefits of grinding – saving production time, unclogging bottlenecks, and having a smooth-running line – almost always offset the cost and result in a substantially more efficient process.

Aerospace components generally have very low Ra surface finish requirements and tighter dimensional tolerances, as well as precise complex shapes and forms. Grinding is much better at producing these precision parts and holding necessary shape and dimensional tolerances due to the way the material is removed. During grinding and machining, the material ground off is removed as chips. In grinding, much smaller chips are created which allows for more precise shapes and smoother surface finishes, while machining produces significantly larger chip formations.

Due to the larger chips and aggressive cuts of material, traditionally, machining has generated higher material removal rates (MMR) than grinding. With newer grinding technology, this isn’t necessarily true. For example, new Norton TQX grain technology has been able to hit Q’ (Q- prime specific material removal rate) values of >3in3/min/in in creepfeed grinding of aerospace components, which is usually the max Q’ achieved with ceramic grain bonded wheels. These values rival those of machining processes. Figure A (pg. 30) shows the improvement of TQX versus other ceramic grains. With the other ceramic grains, as Q’ is increased, G-ratio (the volume of material removed from the work per unit volume of wheel wear) declines and eventually bottoms out at about 3.5in3/min/in. Alternatively, TQX can increase G-ratio with increased Q’ up to 2.5in3/min/in and maintain this high G-ratio at Q’s over 2.5in3/min/in, but in this case, TQX reaches a Q’ of 5.5in3/min/in. This new technology challenges machining processes, producing parts with improved quality and eliminating the need for further finishing processes.

Different material types affect grinding processes, depending on the material hardness, variety of material properties (especially newer alloys), and behavior of the material once it heats up (among other operational factors). This means one grinding wheel type or specification may not work for all materials or it may not work for various material types within similar applications. It depends on many factors, so consult with a grinding expert to determine grinding wheel requirements based on material type, and how to consolidate specifications and wheel sizes to keep inventory levels low.

One issue often seen with some newer alloys and more exotic materials, typically used for turbine blades, is they become gummy or act soft upon grinding, especially prior to heat treatment. Examples include Rene 108 and Inconel. Grinding gummy materials can load up a grinding wheel, which will result in heat generation, burn, poor surface quality, and the need for additional dressing. In this scenario, generally a softer grade, porous grinding wheel is needed with a friable abrasive that’ll fracture a bit easier and produce new, sharp cutting points to continue grinding through the soft material.

Additive manufacturing (AM) for aerospace components adds simplicity to making complex parts, including those with intricate internal shapes and channels. It also gives the ability to produce parts with different metals or materials that weren’t in use before due to difficulty in grinding, machining, etc. With AM growing, grinding is still relevant. For example, an abrasive cut-off wheel can separate 3D-printed parts from their build plate. Afterward, a grinding wheel can grind down this metal plate, flattening it, removing any additive material, and ensuring the appropriate surface finish so the plate can be reused for the next part.

Abrasives are also used in AM finishing steps such as improving dimensional tolerances and surface quality. Although the growing use of AM overall will decrease the need for creepfeed grinding of aerospace components, new requirements will move toward deburring and finish grinding. Parts with precision features will require finish grinding regardless of how they are initially produced. The main difference with finishing 3D-printed parts compared with finishing traditionally made parts may just be that additively manufactured parts need less stock removed to get to the final geometry and surface finish.

About the author: Arianna Smith is corporate application engineer for Norton Saint-Gobain Abrasives. She can be reached at arianna.smith@saint-gobain.com.

Norton’s TQX ceramic grain allows creepfeed grinding at high infeed rates for tough-to-grind materials with high Q’ values. Additionally, Norton’s Quantum grain, NQX, is popular in aerospace component creepfeed grinding as it has a microcrystalline structure that cuts through gummy materials including Rene 108 and Inconel parts such as turbine blades. NQX often results in less dressing amounts/frequency and increased infeed rates compared to other ceramic and aluminum oxide wheels.

Norton’s IDeal Prime ID grinding wheels have an even smaller microcrystalline structure that handles high contact areas in ID grinding for aerospace components requiring bore grinding. The enhanced microcrystalline structure produces improved surface finishes, requires lower machine power draw, and results in cooler cutting during grinding.

In superabrasives, Norton Vitron7 vitrified bonded cBN wheels provide exceptional results in aerospace manufacturing for various applications such as O.D. and I.D. grinding. The enhanced Vitron7 bond is for high volume parts where surface finish and quality are of utmost importance. This bond allows for superior wheel life compared to other vitrified bonded cBN wheels.

A range of Norton abrasive products, such as plated, Vitron7 cBN, NQN grain, and more are available to finish additively manufactured parts. For more information, download the Norton Application Guide for Finishing 3D Printed Parts at https://tinyurl.com/yf4cby7c.