With the right tools, developers can build a software platform that adds a higher level of automation, machine vision, and connectivity to smart factories.
Today's discussion of industry usually focuses on the huge potential of the Industrial Internet of Things (IIoT). It promises to significantly increase productivity, operational efficiency, and bottom-line revenue, but only if the supply chain provides reliability, stability, and longevity. As manufacturers and system integrators adopt more automation, connectivity, and autonomy, these values will become more important-faster design cycles and more competition increase the pressure to enter the market quickly. The interaction between these requirements will define the industrial market and the innovation that developers contribute to it.
Industry 4.0 reveals how IIoT can upgrade the factory floor. With the right functions, it can make any industrial environment smarter, using connections to collect sensor information, and turning yesterday's big data into today's insights.
The industry's need for efficiency is very urgent, so connectivity and efficiency are crucial for developers and organizations to consider throughout the design process.
Supply and price stability ensure that manufacturers can continue to develop, build, deliver, and maintain their systems for a longer period of time. This usually requires component suppliers to guarantee supply continuity for up to 15 years and provide corresponding price guarantees for up to 4 years.
In order to balance connectivity, efficiency, and reliability, developers must choose the right technology for each application.
Take ON Semiconductor's Intelligent Power Module (IPM) series as an example, which uses Insulated Metal Substrate Technology (IMST). This technology integrates many active components on a metal substrate to achieve high integration and excellent thermal conductivity.
Starting with IPM, motor drivers (brushless DC motors, stepper motors, brushed motors), load drivers and relay drivers-a large number of semiconductor technologies-are all used in industrial robots and other IIoT applications. These are supported by more and more optimized metal oxide semiconductor field effect transistor (MOSFET) and insulated gate bipolar transistor (IGBT) drivers and high-performance optocouplers, enabling engineers to develop reliable industrial drive systems that use low-voltage Application of any combination of motor and high current load.
For efficiency and reliability, machine vision temperature, motion, ambient light, and image sensors must be optimized for electrical noise conditions. Then need to filter and amplify the small signal of the sensor, and then convert it into digital data and pass it to the central processing unit. Combined with this is the circuit protection of electrostatic discharge (ESD) protection diodes.
Control components for industrial automation usually involve power semiconductors made using MOSFETs or IGBTs and silicon carbide (SiC) transistors. Manufacturers of switches and power semiconductors now provide equipment that meets the requirements of power inverter circuits and motor drives. Many industries must comply with international standards, so many manufacturers develop parts that meet international quality standards, including ISO 90001:2015 and IATF 16949:2016.
Does your company have a concept for a new product, or an idea to transform an existing product using IIoT technology?
For information on how to get started, please visit https://tinyurl.com/qm4cu88.
The seemingly opposite need to develop more complex circuits in shorter time windows and generally lower budgets is prolific in IIoT, which puts pressure on development teams to bring machines invented before the Internet era. To the forefront of future technology.
For engineers developing and optimizing new products, they must be provided with the tools they need to make the process as simple as possible.
For the design team, the interactive block diagram provides engineers with reference designs for specific applications. Each diagram provides a series of potential solutions for each key functional block in the design. More detailed information of each component can be accessed from the block diagram and added to a custom worksheet to quickly develop design concepts.
When moving to an early evaluation program, developers can now use ON Semiconductor’s Strata Developer Studio cloud connectivity platform as a starting point. Once connected to the host PC, the software will automatically identify the evaluation board, then retrieve the latest design information and automatically configure the evaluation board, allowing engineers to quickly get up and running. Combined with Avnet's global expertise, these designs can go from napkin ideas to design products with manufacturability, strong supply chain and regulatory considerations.
IIoT will cover a wide range of technologies from sensors to the cloud. Robotics and automation are safety-critical applications that require the best solutions. Developers need partners who can provide parts and services to transform ideas into products and products into markets. Avnet and ON Semiconductor have created a product development ecosystem and software platform to reduce design time for developers and speed time to market.
Avnet https://www.avnet.com
ON Semiconductor https://www.onsemi.com
TM Robot integrates traditional machines and advanced artificial intelligence vision (AI) in a single robot system. Elimination of additional controllers reduces integration time. TM Robots' built-in machine vision is integrated with light, industrial cameras and sensing elements to capture images. Deep learning AI technology accurately perceives the shape, type and color of objects to improve detection efficiency in automated production and improve quality and accuracy. Inspection data can guide manufacturing.
TMmanager graphics control software intelligently manages factory processes and equipment in real time. The arm management system is connected to TM's collaborative arm to monitor the operation of the robotic arm in real time. It also manages factory automation equipment, such as shop floor control systems.
The 381LL series snap-in aluminum electrolytic capacitors have an expected life of 8,000 hours under full-rated conditions and demonstrated the stability of capacitance and DC leakage current during the test.
The capacitance range is 740µF to 100,000µF, the operating voltage is 16VDC to 250VDC, and the ripple current rating is as high as 10A at 105°C. The snap-in series is available in a smaller diameter 2-pin configuration, as well as larger diameter 4 and 5-pin options.
General applications include any circuit that requires high capacitance, low equivalent series resistance (ESR), high ripple current, and long life. This includes switching power supplies, uninterruptible power supply (UPS) systems, solar and other high-power inverters.
The MR 30 Monorail 30mm guide rail and cross roller bracket can move workpieces weighing up to 150 tons in a milling machine, lathe, drilling machine or grinding machine.
It provides higher processing speed, enhanced geometric accuracy and improved surface quality of processed workpieces.
This series has an O-shaped geometry, which can achieve extremely high positioning accuracy. Other series features include high rigidity for improved vibration control, greater dynamic and static load-carrying capacity, track straightness and optimized roller and transition path geometry to ensure smooth running, and a complete car shell. Available sizes include 25mm, 30mm, 35mm, 45mm, 55mm, 65mm and 100mm, and can be configured to meet any application specifications, including G3 (standard), G2, G1 and G0.
FreeFlight Systems' 1203C SBAS/GNSS sensor has been approved for installation with the Honeywell TRA-100B Mode S transponder on Boeing 717 aircraft. This Supplemental Type Certificate (STC) provides a single solution for the B717 aircraft to meet EU ADS-B requirements on June 7, 2020. FAA verification is in progress to support U.S. compliance.
This sensor is a certified high-integrity location source. It is paired with a certified Mode S Extended Squitter transponder (such as TRA-100B in transportation aircraft) to provide a regulated ADS-B Out system.
Steps to identify and solve the pollution problem of military aircraft.
Fiber optic connectors in military aircraft applications must be very durable because they are often exposed to severe temperatures, high humidity, strong winds, and excessive shock and vibration. However, although these connectors are strong, they still need to be carefully cleaned before connecting the end faces.
End-face pollution may come from salt spray residue, hydraulic oil, jet fuel, atmospheric dust, penetrating oil, and vehicle emissions. Even removing the dust cap covering the end face from the factory may cause contamination. If these contaminants are left between the paired terminal pairs, they will usually spread to the end surface, changing the signal path and changing the refractive index, resulting in signal attenuation. Severe pollution may cause the entire system to malfunction.
A common source of end-face contamination is wear debris generated when the aircraft is in motion. Sustained vibration will cause surface-to-surface wear between the various components of the mating connector, resulting in dust and contaminants. Commonly used MIL 38999 cylindrical connectors with MIL 29504 terminals are most commonly used in cable-to-panel input/output (I/O) applications in the aerospace industry. When exposed to high vibration, shock, and shock motion, the spring-loaded terminal maintains physical contact. However, the strong contact force that connects the paired terminals together can also grind dust particles to the surface of the ferrule, scratching the end surface.
Due to the accumulation of static charges on the ceramic and composite ferrule materials, end-face contamination will worsen. The ferrule and glass fiber are dielectrics, which act as electrical insulators and maintain static charges. The charged dust particles will be attracted by the oppositely charged fibers and ferrules. MIL 38999 and MIL 29504 allow the end face geometry to be a convex curve, concentrate static charges on the apex of the mating connector, and physically attract dust contamination to physical contact. The lower the humidity, the greater the problem of static electricity.
The MIL 38999 connector is designed to withstand the extreme mechanical stress and harsh environment of military aircraft combat. Its depth is too deep to be cleaned with traditional optical fiber cleaning tools, and it is time-consuming and expensive to remove the adapter and connector to clean the fiber end face . Special tools and methods are needed to clean them effectively. In order to achieve the best performance of the aircraft optical network, fiber optic technicians should:
Prepare for cleaning-if possible, clean in a closed area, such as an airplane hangar. Cleaning the fiber on the ramp of the aircraft exposes the connector to dust and debris.
Before disconnecting the end face, thoroughly clean the outside of the mating optical fiber connector with an aerosol dust collector and general cleaning wipes. However, do not use the dust collector product directly on the end face after disconnecting, because the movement of the dust collector gas will generate static electricity and draw dust and other pollutants into the end face.
Clean inspection tools and adapters to prevent cross-contamination.
Choose the right cleaning fluid-optical-grade cleaning fluid designed specifically for fiber end faces is the best. Choose ultra-pure, non-flammable, and residue-free cleaning fluids that are safe for glass, ceramic and plastic surfaces. The fluid should be contained in a sealed (non-refillable) container to prevent cross-contamination and spillage. The fast-drying, static dissipative fluid also eliminates additional drying, thereby saving time.
Avoid using water-based cleaners because they dry slowly and freeze at low temperatures. In addition, avoid the use of isopropyl alcohol (IPA). Although it is cheap, alcohol is flammable and must be kept away from sources of ignition. IPA also easily absorbs moisture from the air, thereby polluting it.
Use wet/dry cleaning to dissipate static electricity-During wet/dry cleaning, use a section of optical grade cleaning cloth and soak it with static dissipative cleaning fluid. Wipe the end face of the connector from the wet area, moving in one direction toward the dry area of the cleaning cloth. This step removes pollution and dissipates static electricity. The port cleaning stick or the click device should be soaked with cleaning fluid first, and then used to clean the end surface.
Choose high-end optical wipes-Cheaper paper towels rarely remove microscopic contaminants from optical connectors because they tend to tear easily. When they degrade, they leave lint and debris. They usually generate high electrostatic charges, making their use counterproductive. High-quality optical wipes that do not shed hair or generate static charges are the first choice. Buy smaller wipes to reduce waste and save money. Use the wet wipes in the package to minimize static charge when dispensing individual wipes. Leaving the wipes in the packaging until they are ready to use ensures that they stay clean and prevent waste. Use the wiping cloth only once to prevent cross-contamination of the network end face.
Use a cleaning stick for better cleaning-although mechanical clickers are usually great for cleaning connectors, their size is not always suitable for cleaning terminals in hardened connector housings. Use a combination of cleaning rods and static dissipative cleaning fluid to clean connectors installed in difficult-to-clean positioning sleeves. The cleaning rod conforms to the end face geometry, and the entire end face can be cleaned without disassembling the connector or adapter. They clean the terminal surface and eliminate problems associated with contaminants migrating into the signal path. The cleaning fluid will also increase the local humidity and create a dissipation path to remove any existing static charges.
When cleaning, first moisten the cleaning rod with cleaning fluid. After inserting the rod into the connector, rotate it about six times in the same direction. Avoid excessive force and do not scrub the end face excessively, as this can cause scratches, pits, or scars. The design of the cleaning rod should match the configuration of the end face, and it will not shed hair to achieve the best cleaning effect. The well-designed cleaning rod will accidentally contact the side wall of the alignment sleeve, so that the cleaning fluid can eliminate the static charge, so during the insertion process, any debris on the alignment sleeve will not jump to the clean connector end surface superior. The cleaning stick should be kept in the packaging until it is ready to be used to prevent soiling or damage.
Inspect-clean-inspect-Before mating, always inspect, clean and re-inspect all terminals at both ends of the connector pair. Visual inspection can identify permanent defects, scratches, pitting, and contamination that may interfere with or damage the surface of the optical terminal.
Take the time to visually inspect the terminal to identify possible sources of contamination and try to eliminate the underlying problem. Only when the surface of the terminal is not contaminated, the connector pair can be paired. Careful cleaning and inspection of both ends before pairing will ensure the reliability and longevity of military aircraft fiber optic networks.
The frequency required to clean the fiber optic connectors on the aircraft will vary, but technicians should implement a maintenance plan.
The cleaning procedure is simple. Personnel should strictly abide by the technical manual in order to properly clean and maintain the fiber optic system. If the technician is not in a hurry to complete the process, the connection will have a higher integrity throughout the life cycle of the fiber optic system.
In addition to regular maintenance, if the system shows any communication signal degradation, the fiber optic connections should be cleaned.
When choosing fiber cleaning fluids, tools, and methods, technicians should seek help from experienced suppliers who specialize in military fiber cleaning. Suppliers can recommend specific products designed for military use that can effectively clean unique military connectors used in harsh environments.
About the author: Jay Tourigny is the senior vice president of MicroCare Corp. You can contact him at techsupport@microcare.com or 800.638.0125.
CAM technology keeps pace with the challenges of aerospace manufacturing.
Advances in materials and engine efficiency have created obvious benefits for replacing old aircraft. The demand is so great that machine tool manufacturers are facing the challenge of providing aircraft manufacturers and their suppliers with sufficiently fast equipment. Increasing the number of spindles is difficult and expensive, so some manufacturers are responding by increasing the productivity of tooling, workpiece clamping, and CAM software solutions. The enhancement of supporting technology can increase the productivity of existing equipment and reduce the need for new machines.
Many CAM systems focus on processes such as 5-axis milling, turning and milling, wire EDM, or mold applications. Therefore, the ideal CAM software for aerospace must be good at removing large amounts of aluminum from structural components and used in conjunction with high-precision, high-temperature resistant titanium or nickel-based superalloy compressors and turbines.
High-performance rough machining enables aluminum blocks or plates to reach a near-net shape, where 90% or more of the block weight may be removed. This is important in typical 3-axis structural parts, and crucial in 5-axis parts. Many CAM programs have high-performance roughing modules that use cycloid technology. Open Mind's hyperMILL MAXX Machining roughing module has been expanded to be suitable for 5-axis roughing. For formed structural parts (wing segments or doors), 5-axis roughing facilitates the subsequent processing.
The surface of standard structure parts is processed by side edge milling, and the side of the tool is aligned with the side of the part, which can achieve good performance, but it is limited to the wall surface with a height of 50 mm. For larger walls, chip milling may cause tool or wall vibration. Multiple steps with overlapping and inconsistent deflection patterns are also possible. The next best option is to perform point milling in many paths by using the tip of a ball nose end mill with a small step. Unfortunately, point milling can significantly increase cutting time.
Open Mind's hyperMILL MAXX Machining uses tapered barrel milling cutters (also called arc segment or arc segment end mills) with a barrel contact radius of 1,000 mm or more, which can produce 10 larger than ball end mills To a 15 times wider step. This can reduce cutting time by 90% or more. Compared with the traditional barrel knives, the conical barrel knives have a large barrel radius on the tapered feature, and the large radius of the traditional barrel knives merges into a tangent to the handle.
The taper allows the tool axis to be pulled away from the surface being cut. The result is a shorter, harder tool without interference from the tool holder. Although tangent barrel knives provide some benefits, tapered barrel knives can achieve a larger barrel radius to allow shorter knives without interference from the tool holder.
The tapered barrel knife has a long life and consistent processing performance. In addition, the ball head at the tip of the tapered barrel cutter can be used to clean fillets and mixed surfaces with the same cutter.
A single blade of a turbine engine can be machined from rectangular blocks, cylindrical blanks or near-net forgings. Rough machining is a key task for cost control and preparation of finishing operations. Due to various starting blank shapes and irregular finishing shapes, blank tracking is essential in the roughing process to avoid wasteful air cutting. Since the insert can be twisted, multiple cutting directions should be used during roughing in order to leave minimal inventory for finishing.
Single-edge finishing is usually performed with a ball end mill, especially on twisted surfaces and close to the connecting platform. The open area of the blade surface is usually cut with an inclined bullnose knife. Compared with ball end mills, this cutting method provides a larger effective radius of curvature, and can produce fine surface finishes in fewer passes. Recent developments also include the application of large-angle tapered barrel knives on single-blade components.
Due to the tight blade pitch and the requirement for high aspect ratio tools, finishing multi-blade components—turbine blisks (blisks)—brings additional challenges. CAM collision detection and avoidance technology can find a solution in the close spacing between the blades.
The small tool radius imposed by blade spacing, fillet geometry, and fine surface finish specifications may require hundreds of machining around the blade with a ball end mill. Applying long path lengths to hard metals is time consuming and can cause tool wear and manufacturing consistency issues. Some engine manufacturers change the tool for each subsequent blade surface to ensure uniform wear and reduce the unbalance of the machined parts.
Distorted multi-blade surfaces usually do not allow chip milling. The tapered barrel knife solution is also used to achieve cycle time and quality improvement. Compared with ball end mills, larger steps can reduce the total path length and tool wear.
Single-blade and multi-blade components can be classified by programming based on features and part families (macro). The repeated geometric selection of curves and surfaces is more complicated than typical holes and cavities, but can be represented by feature definitions. When programming multiple parts, it is very useful to use the best practices of materials and tools, including feedrate and spindle speed, tool holder, step and step distance. The comprehensive part series strategy reduces the programming effort of many parts while achieving high productivity.
CAM has a great influence on machine tool performance, so users can benefit by choosing the right software for the application. The most advantageous CAM software will continue to evolve with each new version released to provide enhancements and innovations that keep up with the requirements of aerospace manufacturing.
About the author: Alan Levine is the managing director of Open Mind Technologies USA Inc. You can contact him at alan.levine@openmind-tech.com.
Optimized flash memory technology can ensure host architecture compatibility while meeting application workload requirements.
Technology based on the Industrial Internet of Things (IIoT) is growing exponentially, and Industry 4.0 has triggered a wave of change that is rapidly changing the way aerospace manufacturers operate.
One challenge is to manage the massive amounts of data generated by IoT systems in the aerospace industry. A jet aircraft can generate hundreds of gigabytes of data per minute. And data storage devices must operate in extreme environments. For IIoT applications to capture, store, analyze, and share information, they need multifunctional storage devices that can withstand high and low temperatures, humidity, and vibration.
The ruggedness of industrial flash memory devices provides solutions for applications such as helicopter black box recording, jet mission data collection, drone base stations and flight data recording, and in-flight entertainment and WiFi services.
Industrial flash memory devices must be able to handle large amounts of data and operate in the temperature range of -40°C to 85°C for long periods of time without failure. The ruggedized device uses a single-level cell non-and (SLC NAND) architecture because it is more reliable for IIoT uses.
Unfortunately, many aerospace manufacturers treat flash memory as a commodity and purchase commercial off-the-shelf (COTS) parts that meet the type, memory capacity, and form factor. They may ignore considerations such as workload (the frequency of reading/writing large amounts of data), power management (dirty power, power cycling, power failure), and environmental conditions (temperature, vibration). These factors may damage data and cause other errors, thereby reducing storage reliability and service life.
"Many aerospace manufacturers purchase flash memory devices through the Internet, but found unexpected problems due to inaccurate assumptions about the environment and workload requirements when the product was released," said the product manager of Delkin Devices-Volatile Flash Solid State Drives (SSD), cards and modules.
In the aerospace sector, this can lead to unexpected failure of mission-critical data and compromise safety functions. Considering the important role of storing mission-critical data, Diaz said that most industrial flash storage devices require some customization to meet real-world workload requirements.
The life span of all-flash storage is limited, depending on its management and workload requirements. To optimize and extend the lifespan of flash memory devices, carefully consider how data is written.
New data cannot be saved to the flash memory before the old data is erased, and a limited number of program/erase cycles can only be performed before wear makes the flash memory unreliable. Some flash media are used unevenly, further shortening the service life of the device.
Options for extending the life of flash memory devices include reducing unnecessary file copying or data downloading, integrated writing, wear leveling technology, and choosing whether data is written sequentially or randomly.
"If aerospace manufacturers misjudge or misunderstand the workload requirements, it will have an impact on storage," Diaz explained. "It may be as simple as an unexplainable error on the spot, or it may be that they run out of flash memory much faster than they realize."
When customizing flash memory, consider mechanical robustness. Q. Is the application subject to abnormal amounts of vibration? Does the typical operating environment exceed standard industrial storage parameters?
Despite the rugged design, each industrial flash memory application has different operating requirements. Custom mechanical robustness can alleviate concerns about failures related to operating conditions.
To ensure that storage devices work as expected, please cooperate with manufacturers that provide reliability testing services. Delkin Devices provides design verification testing, continuous reliability testing, and accelerated ramp-up testing at its manufacturing facility in San Diego, California to simulate long-term operating conditions.
If the data is not completely saved, power failure during the write operation may result in data loss. Even a small amount of data loss during a power failure can cause serious persistent problems, including fatal damage to the entire system. It may also lead to inefficient use of memory capacity, thereby greatly shortening the service life of embedded flash memory.
Reducing the source of external power loss can reduce the risk of power failure. However, power failures may still occur, so internal protection is essential to reduce the risk of data loss. For flash memory systems that handle critical data, this means built-in power failure control, including systems for monitoring power and the ability to recover data after a power failure during write operations.
Dirty power caused by power outages, insufficient power, power surges, and power spikes is another problem. When direct current (DC) falls below the required threshold, equipment critical to the operation of an aircraft or spacecraft may experience errors.
How manufacturers purchase parts, cooperate with suppliers, and ensure that purchased parts are available throughout the product life cycle are important issues.
The bill of materials (BOM) of commercial-grade flash memory is often updated without warning. While this helps consumer manufacturers maximize functionality while minimizing prices, aerospace manufacturers need consistency and reliability.
Diaz said that when parts are under control and locked in configuration, manufacturers can achieve higher standards.
"Once qualified, as long as the part number is valid, the flash memory, controller, and firmware will not change. If anything needs to be changed, changing the part number basically guarantees that the customer will be notified and the BOM updated," Diaz explained.
COTS flash memory may have the correct specifications and cost less than the supplier's custom parts, but there are always hidden costs and risks.
Diaz said that manufacturers should work with suppliers from the very beginning of the design process to ensure they get what they need for the entire life cycle of the product.
"Aerospace manufacturers may not spend too much time thinking about flash memory," Diaz added. "But given the critical nature of data in today's devices, taking industrial flash memory for granted is too risky."
How compliance and collaboration can electrify aircraft.
Power conversion is a unique challenge when designing converters for critical applications such as engines or flight control systems. Since manufacturers usually do not redesign these complex systems, most commercial aircraft today will be equipped with power sources in the engine control system designed 25 years ago—proven and clockwork-like performance.
However, if aerospace original equipment manufacturers (OEMs) plan to use newer technologies to improve efficiency, then the mentality of “if it’s not broken, don’t fix it” will change. Where the old converter design may have an efficiency of 70% to 75%, the newly designed version should provide more than 90% performance efficiency while ensuring safety compliance. To develop smarter technologies for today and make breakthroughs in tomorrow's electric aircraft, progress and performance must be free from resistance to change.
Since production is dominated by a few large industry players, existing power converters (such as autotransformer rectifier units (ATRU)) are based on decades-old technology and usually do not meet the latest airframe harmonic requirements. Used to connect electronic devices to the power source of the fuselage, non-compliant ATRUs usually must obtain performance exemptions from the OEM; these exemptions essentially recognize small interruptions in performance. ATRU is safe, but non-compliance with the standard will result in greater thermal effects on the aircraft, and greater restrictions on the systems and functions that can be designed into the fuselage. As aircraft changes and technology advances, these restrictions will no longer be accepted. In order to obtain the best performance and competitive value, there is a new push for ATRU technology that fully meets the harmonic requirements of advanced aircraft.
At the same time, because ATRUs are an integral part of electronic aircraft systems, they have become a key driver of manufacturers’ revenue even if manufacturers lack a deep understanding of how their own equipment is designed. Because these companies generally do not have the on-site expertise to implement power conversion designs in their facilities, a new market is emerging for products that are fully compliant and implement safety-critical functions from the earliest design stage.
The system must be safe under any circumstances, but just because the system is effective does not mean that it fully complies with safety standards. Innovators are responding to this challenge by developing a powerful, safety-critical series of converters to power the brains of aircraft systems such as engine control or fly-by-wire control systems. To ensure optimal power generation, energy must be drawn from the generator in a sinusoidal manner to reduce the negative effects of harmonics and heat on the wiring. However, this design is complex, so expertise must focus on the safety-critical aspects of performance. Consider a simple power converter input filter. Even if the paired voltage converters seem to work properly, they may not be able to solve the quirks and quirks of this basic circuit. Complex systems have potential particularities—such as abnormal voltages on a single rail—require specific design talent to avoid system failures.
Compliance and safety lay the foundation for smart design and achieve superior performance, including the improvements needed to drive engineering breakthroughs in modern aircraft design. For example, meeting input current harmonic specifications can ensure safety and protect the interests of aircraft manufacturers, while also positioning the industry to unleash the potential of multi-electric aircraft (MEA). This is a key entry point for future aircraft design, because as aircraft become more electrified, more electrical systems will be added. All-electric aircraft will require tighter and lower system input current harmonics, and manufacturers will face an ever-evolving goal of drawing higher levels of power from generators in use.
In January 2020, TT Electronics acquired a business unit in Covina, California from Excelitas Technologies Corp of Waltham, Massachusetts, which designs and manufactures power electronics for the aerospace and defense (A&D) market.
This acquisition strengthens TT's American influence in the field of A&D power electronics, and provides an opportunity to obtain a growth plan with exclusive source status. This position holds several major US defense giants.
In this case, companies with a global footprint and deep expertise are also playing a role in driving overall industry innovation and technological breakthroughs—not to mention helping aerospace leaders stay relevant to future engineering systems. By recruiting talents from system manufacturing and design engineering, innovators are forming teams with rich experience in developing power electronic systems. This has created a major industry shift, filling a gap in companies that can provide a wide range of solutions, and enabling industry participants to redirect design resources to the next level of aircraft integration.
The autotransformer rectifier unit (ATRU) converts the alternating current generated by the generator into direct current. There may be hundreds of ATRUs on an airplane, which can handle various power demands from 1kW to 250kW. These simple and reliable devices use polyphase transformers, power diodes, and electromagnetic interference (EMI) filters to provide quality power.
However, traditional ATRU introduces unwanted harmonics into the system instead of providing the required smooth sine wave current drawn from the sine wave voltage. This does not meet the acceptable harmonic levels defined by the comprehensive DO-160X industry specification and requires aircraft manufacturers to grant exemptions for any ATRU design that does not meet the specifications. Although the exemption does not mean that the equipment is unsafe, it acknowledges that less efficient equipment being used will generate more heat, thereby limiting the number and types of electrical systems that can be added to the aircraft.
Compliance changes this situation: compliance with the DO-160 standard provides manufacturers with a way to fully utilize the power potential of their designs in the same or even smaller ATRU footprint. This is a big win for advanced aircraft systems that rely on the generation and transmission of fixed power—allowing competitive differences.
Compliance exemptions are coming to an end, creating a virtuous circle of innovation, which is essential for improving safety compliance and developing breakthroughs to drive the growth of electric aircraft. The industry should recognize this tremendous change and develop a greater awareness of the challenges, possibilities, choices, and leadership opportunities driven by superior power conversion.
About the author: Julian Thomas is the director of engineering for the power and hybrid business unit of TT Electronics. Contact him via julian.thomas@ttelectronics.com or LinkedIn.