Raytheon Technologies (Poland)

This chapter covers each of the ROIC functions shown in Fig. 5.1, including preamplifier, signal processor, multiplexer, and video amplifier sections. These functions are addressed in terms of major design drivers such as noise, dynamic range, and power. Since the signal-to-noise ratio (SNR) is the major driver in most sensor designs, each ofthe circuits is detailed in this context. The simplest circuits are introduced first to provide the basis for more advanced circuits. The resistor trans impedance amplifier (RTIA), which is most common in discrete configurations but also utilized in ROIC configurations, will be addressed initially to introduce many of the basic signal and noise concepts required for analysis of other preamplifier circuits in subsequent sections.

Abstract The safe and reliable operation of insulation material used in key high voltage components under extreme environmental conditions represents the major concerns for manufacturers and operators of More Electric Aircrafts (MEA). Surface discharge occurring in high current carrying components in DC power system diminishes the insulation material’s performance and life, especially at high‐temperature conditions. Here, the surface discharge behaviour of two commonly used high‐temperature insulation materials, ethylene‐tetrafluoroethylene (ETFE) and polyetheretherketone (PEEK) is studied at different temperatures under ramp and DC voltages. Extracted partial discharge (PD) features are presented and the impact of voltage polarity on surface discharge propagation is discussed. Our studies reveal that, while both materials exhibit non‐linear PD behaviour with respect to their electrical conductivity, ETFE generally shows PDs with higher intensity at high temperature above 100°C with a higher possibility of surface discharge due to its lower permittivity. Overall, the PD mechanism in high‐temperature, DC voltage applications is explored, and a basis for the selection of high‐temperature PD suppressing materials is developed.

Abstract A micromechanics‐based modeling approach that allows for the simultaneous consideration of deformation, damage, and oxidation associated with each constituent of silicon carbide (SiC)‐based ceramic matrix composites (CMC), including the fiber, fiber coating, and matrix, is described. Chemical kinetics models from the literature are combined with a progressive damage model. Rupture predictions of unnotched and notched stress‐hold (creep) specimens are compared with experimental measurements from a SiC/SiC CMC to assess the efficacy of the modeling approach. Techniques of improving creep rupture life are explored using the model.

A reinforcement learning-enabled microgrids interconnection (RL-MIN) control strategy is presented to interconnect microgrids through automatically adjusting the control of distributed energy resources (DERs). RL-MIN is trained to gain the generic knowledge of microgrids and generate corresponding controls for DERs with an aim towards interconnecting systems in a seamless fashion. Using RL-MIN, microgrids can be smoothly connected to form a more stable system when necessary or to energize a large region after a black out occurs. Therefore, the power grid resilience can be significantly enhanced. Numerical results validate the effectiveness of RL-MIN in gaining system operational knowledge, generate corresponding controls for DERs, and interconnect microgrids seamlessly. These salient features make RL-MIN a powerful tool for operating future microgrid systems and contributing to the resilient operations of the bulk power grids.

Abstract The paper presents a novel application of the State Dependent Riccati Equation (SDRE) guidance approach with state constraints for a chaser spacecraft in the close proximity of a passive target. The dynamics are described by full 6 degree of freedom rigid-body relative motion. The final trajectory is defined by a passively safe approaching cone, which acts as path constraint and follows the attitude motion of target. A Near Rectilinear Halo Orbit in the Earth-Moon system is the selected rendezvous scenario to fully validate the proposed solution, even though the parameters related to the constraints and weighting functions are kept as general as possible, thus applicable to other similar missions.

Raytheon Technologies Research Center (RTRC) is currently developing a high power-density motor (12kW/kg) under the ARPA-E ASCEND program. In this paper, we present innovative and unique aspects of a "triple rotor" tightly coupled with a planetary gearbox (GB). The rotor design is unique and makes full use of the electromagnetic potential of permanent magnets (PM). The high speed of the motor is reduced to the target application speed by a planetary GB embedded within the profile of the "inner rotor". The design is guided by the stress and rotordynamics analysis and the GB modeling. Also presented is the risk reduction hardware built to validate the manufacturing process. The program is continuing and in the next 2 years, the RTRC team, supported by Collins Aerospace, will build and test a full 250kW demo. The test results will be presented in a paper on the demonstration.

As Computer Mediated Communications (CMCs) advance, businesses have sought alternatives to face-to-face (F2F) meetings to increase productivity for geographically dispersed teams while saving time and money. However, critical differences between CMCs and F2F impact multiple aspects of communication performance. In order to investigate these variations, the current research investigated the communication effectiveness in three distinct scenarios: video conferencing (VC), virtual reality (VR), and face-to-face (F2F). The study involved an electrical circuit repair task and the administration of multiple surveys to gather data from a total of 104 participants, focusing on four dependent variables: shared situational awareness, usability, mental workload, and performance confidence. For all the variables, results showed significantly better scores in VR and F2F conditions than in VC, but there was no significant difference between the VR and F2F conditions. These findings can inform technology developers in improving communication performance in computer mediated contexts, especially by using VR.

Over-approximated Worst-Case Execution Time (WCET) estimations for multi-cores lead to safe, but over-provisioned, systems and underutilized cores. To reduce WCET pessimism, interference-sensitive WCET (isWCET) estimations are used. Although they provide tighter WCET bounds, they are valid only for a specific schedule solution. Existing approaches have to maintain this isWCET schedule solution at run-time, via time-triggered execution, in order to be safe. Hence, any earlier execution of tasks, enabled by adapting the isWCET schedule solution, is not possible. In this paper, we present a dynamic approach that safely adapts isWCET schedules during execution, by relaxing or completely removing isWCET schedule dependencies, depending on the progress of each core. In this way, an earlier task execution is enabled, creating time slack that can be used by safety-critical and mixed-criticality systems to provide higher Quality-of-Services or execute other best-effort applications. The Response-Time Analysis (RTA) of the proposed approach is presented, showing that although the approach is dynamic, it is fully predictable with bounded WCET. To support our contribution, we evaluate the behavior and the scalability of the proposed approach for different application types and execution configurations on the 8-core Texas Instruments TMS320C6678 platform, obtaining significant performance improvements compared to static approaches.

We propose a novel robust decentralized graph clustering algorithm that is provably equivalent to the popular spectral clustering approach. Our proposed method uses the existing wave equation clustering algorithm that is based on propagating waves through the graph [1], [2]. However, instead of using a fast Fourier transform (FFT) computation at every node, our proposed approach exploits the Koopman operator framework. Specifically, we show that propagating waves in the graph followed by a local dynamic mode decomposition (DMD) computation at every node is capable of retrieving the eigenvalues and the local eigenvector components of the graph Laplacian, thereby providing local cluster assignments for all nodes. We demonstrate that the DMD computation is more robust than the existing FFT based approach and requires 20 times fewer steps of the wave equation to accurately recover the clustering information and reduces the relative error by orders of magnitude. We demonstrate the decentralized approach on a range of graph clustering problems.

Due to the COVID-19 pandemic and compulsory social distancing, researchers in educational fields started to investigate alternatives to face-to-face (F2F) training methods with greater focus, such as video conferencing (VC) and virtual reality (VR) applications. This study investigated the differences between VC, VR and F2F training conditions by evaluating the level of body ownership and agency perceived by trainees. An electrical circuit repair task and multiple surveys were used to gather data from 106 participants in the form of four dependent variables: a circuit knowledge test, task completion rate, number of the subtasks completed by failing participants, and test phase duration. The study included two visits by each participant to measure knowledge retention while there were no training and surveys in Visit 2. Results showed significantly higher circuit learning and knowledge retention scores in F2F and VR conditions than in VC. Also, regarding the retention of knowledge, participants had significantly better knowledge retention in Visit 1 than Visit 2. The authors hope the results of this study enable training developers to enhance the learning process in computer mediated communications.

End item deliveries to government customers are usually accompanied by a multitude of required documents, typically in print-ready formats such as Microsoft Word or Adobe Portable Document Format (PDF). Preparing these documents requires tedious manual collation and re-formatting of data from a multitude of data sources, which takes a significant amount of labor, is error-prone, and incurs lengthy review and approval cycles.How can we modernize our document preparation to support continuous release and delivery? Continuous Documentation (CDoc)! By leveraging the Authoritative Sources of Truth (ASOTs) for data already within our DevSecOps pipelines, we can extend the concept of “Documents as Code” (DaC) to reliably and repeatably automate document preparation using a suite of Free and Open-Source Software (FOSS) tools. Continuous Documentation ensures documents are ready for delivery and release in the print-ready formats customers expect at the same time as the software they accompany.

The development and implementation of silicon carbide (SiC) devices is steadily increasing facilitating the electrification of air carriers. In this paper, a print circuit board (PCB) based heavy copper busbar design and verification are introduced for a SiC based 250 kW multiphase drive system operated at 40,000 ft. Finite-element analysis (FEA) simulation studies of the PCB busbar are conducted to optimize the electric field intensity. Busbar modeling technic is also discussed to derive the current distribution and extract the loss. The measured partial discharge inception voltage (PDIV), switching transients and converter-level validations are provided for insulation, thermal and commutation loop verifications.

I present an innovative registration algorithm using the particle flow filter. The particle flow filter is a Bayesian filter that uses particles to represent probability densities. The particle flow filter is not constrained to the highly restrictive unimodal, linear, and Gaussian assumptions of many Bayesian filters such as the Kalman filter. Additionally, the particle flow filter is computationally more efficient than other multimodal filters such as the better-known particle filter (PF). Unlike the PF, the particle flow filter does not require particle resampling or importance weight updates. Rather, the proposal density is formed by flowing the prior probability to the posterior using the Fokker–Planck equation. The particle flow filter algorithms were implemented using MATLAB. Both 2D and 3D rigid body point-set registration were conducted using the Gromov particle flow filter variant. Additionally, the PF method and iterative closest point (ICP) algorithms were implemented for comparison. For the same alignment accuracy, the new particle flow filter approach was 244% faster than the PF for certain challenging problems. For the same alignment time, the particle flow filter reduced misalignment by as much as 35% over that of the PF. The particle flow filter achieved 100% alignment with enough particles, and reduced misalignment by as much as 75% over that of ICP. These results demonstrate that image registration via the particle flow filter significantly outperforms the PF and ICP algorithms in the presence of noise and for a high degree of initial misalignment.

Abstract In this work, TiO 2 thin films deposited by the atomic layer deposition (ALD) method were treated with a special N 2 O plasma surface treatment and used as the gate dielectric for AlGaN/GaN metal insulator semiconductor high electron mobility transistors (MISHEMTs). The N 2 O plasma surface treatment effectively reduces defects in the oxide during low-temperature ALD growth. In addition, it allows oxygen atoms to diffuse into the device cap layer to increase the barrier height and thus reduce the gate leakage current. These TiO 2 films exhibit a dielectric constant of 54.8 and a two-terminal current of 1.96 × 10 −10 A mm −1 in 2 μ m distance. When applied as the gate dielectric, the AlGaN/GaN MISHEMT with a 2 μ m-gate-length shows a high on/off ratio of 2.59 × 10 8 and a low subthreshold slope (SS) of 84 mV dec −1 among all GaN MISHEMTs using TiO 2 as the gate dielectric. This work provides a feasible way to significantly improve the TiO 2 film electrical property for gate dielectrics, and it suggests that the developed TiO 2 dielectric is a promising high- κ gate oxide and a potential passivation layer for GaN-based MISHEMTs, which can be further extended to other transistors.

During the past 15 years, Adaptable Systems Engineering or Adaptive Systems Engineering (ASE), has been establishing itself as a systems engineering discipline, especially since the breakthrough of concept and methodology in the development of the Adaptable Vehicle Make (AVM) portfolio of programs of the Defense Advanced Research Projects Agency (DARPA), the central research and development organization for the US Department of Defense. In ASE, systems engineers use the concept of system adaptability and adaptation techniques in solving systems engineering issues. In this paper, we review ASE’s perspective for Complex Adaptive Systems (CAS), by summarizing the research progress in this area during the past 15 years. We look at ASE’ building blocks which span fundamental modeling factors, measures, missions and requirements, switching costs, etc. and show the applicability of these to CAS. The review will help system engineers and researchers quickly capture the major results and state-of-art methods in CAS engineering, and provide many opportunities for future research and industrial applications.

In this paper, we discuss an analysis method to describe the human and automation roles in increasingly autonomous aviation systems. Specifically, we discuss the relationship between humans and automation in the performance of individual functions in two dimensions, related to their responsibility and authority for the control loops associated with an individual intended function. This work builds upon concepts and terminology proposed by ASTM International in Autonomy Design and Operations in Aviation: Terminology and Requirements Framework (TR1) published in 2019 and is based in part on the on-going work of an ASTM Working Group (WK76044) under F39 Aircraft Systems. TR1 presented a Contextual Framework for analysis of automated aviation functions, and the working group is developing a practice for its implementation.The role of the human vs. the role of automation, which has been extensively discussed in the past, is fundamental to the implementation of the Contextual Framework. As such, it is worth a fresh look, particularly against the backdrop of the Contextual Framework. Our work has led to an analysis of the system state, which at any given time is defined by the role of the human and the role of automation in a two-dimensional space. We refer to this as Dimensional Role Analysis which uses a directed graph approach to clearly depict the nominal operating mode, the revisionary modes, and the triggering events that would cause transition. The analysis approach helps to establish clear delineations as to the responsibility and authority of humans and automation in the performance of individual intended functions. This work makes a clear distinction between authority, responsibility, and accountability consistent with the work of ASTM.Using the concepts and language presented in this paper could add clarity to discussions in the aviation community, as proponents seek to certify and obtain operational approval for increasingly autonomous systems in aviation. While this paper focuses on aircraft control, these approaches could also apply to other safety critical systems.

This paper presents thermal design of a 1kV, 500A T-type modular DC circuit breaker. Along with the thermal design, which determines the trip/protection curve of the breaker, experimental results of the breaker are also presented in this paper. The breaker is over 99.5% efficient that is evaluated using both thermal measurements and millivolt meter for improving the accuracy of measurements. In addition, experimental results shows that T-breaker can break a fault current of up to 4.24 kA, which is approximately equal to 8.5 times its rated current.

This paper presents the study of microstructure and properties of 8 mol% yttrium stabilized zirconia coating fabricated by Plasma Spray Physical Vapor Deposition technique on commercial pure titanium. The coating was characterized by X-ray diffraction, high resolution scanning electron microscope, profilometer, nanoindentation and nanomachining tests. The X-ray phase analysis exhibit the tetragonal Zr0.935Y0.065O1.968, TiO and α-Ti phases. The Rietveld refinement technique were indicated the changes of crystal structure of the produced coatings. The characteristic structure of columns were observed in High Resolutions Scanning Electron Microscopy. Moreover, the obtained coating had various development of surfaces, thickness was equal to 3.1(1) µm and roughness 0.40(7) µm. Furthermore, the production coatings did not show microcracks, delamination and crumbing. The performed experiment encourages carried out us to tests for osseointegration.

Conversion coatings containing hexavalent chromium are currently used in aerospace and defense manufacturing on various aluminum alloys to provide corrosion protection and enhanced adhesion of subsequent coatings. However, hexavalent chromium is toxic to humans with negative health effects from acute and chronic exposure. Regulatory mandates have accelerated a global effort to replace hexavalent chromium-containing materials because of their toxicity. A consortium was established to evaluate safer conversion coating materials, including the chemical processing of the surfaces prior to applying the conversion coatings. Four conversion coatings without hexavalent chromium were compared against a hexavalent chromium-based conversion coating for the following tests: coating weight, electrical contact resistance, paint adhesion, bare and painted neutral salt fog corrosion tests, painted SO2 salt fog corrosion test, and painted outdoor beachfront corrosion test. The test results for the four conversion coatings without hexavalent chromium were encouraging since several candidates exceeded some of the specification requirements or consortium expectations. In particular, the Socosurf TCS/PACS conversion coating performed well in the coating weight, electrical contact resistance, paint adhesion, and corrosion tests. The results of this evaluation provide significant progress toward providing a replacement material for a traditionally hexavalent chromium material application on aluminum.

Abstract A core challenge in modern systems engineering is executing the Digital Transformation to produce Digital Engineering (DE) products that meet traditional program needs. Model Based Systems Engineering (MBSE) focuses the formal application of models to support the systems engineering process, but is often difficult to apply in practice due to a lack of a well‐defined methodology. This paper first introduces an openly available MBSE methodology concentrating on a development process for system architecture models, a style guide defining how the process steps are executed, and a validation suite which serves as a tool to help execute development. Then, this paper describes the experience in applying this process to a DoD program developing a space‐based sensor system to a Critical Design Review (CDR) level of maturity. Real‐life successes and lessoned learned are described through model metric data pulled directly from the SysML development model. This paper concludes by identifying opportunities for future research/work from which to further build the DE/MBSE capabilities of the model.