Your Selections

UTC Aerospace Systems
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Methodology for Formal Requirements Validation and Automatic Test Generation and Application to Aerospace Systems

UTC Aerospace Systems-Eelco Scholte, Rob North
United Technologies Research Center-Orlando Ferrante, Simone Rollini, Luca Manica, Valerio Senni
Published 2018-10-30 by SAE International in United States
Automation on Validation and Verification (V&V) leveraging Formal Methods, and in particular Model Checking, is seeing an increasing use in the Aerospace domain. In recent years, Formal Methods have been used to verify systems and software and its correctness as a way to augment traditional methods relying on simulation and testing. Recent updates to the relevant Aerospace regulations (e.g. DO178C, DO331 and DO333) now have explicit provisions for utilization of models and formal methods. In a previous paper a compositional methodology for the verification of Aerospace Systems has been described with application to Electrical Power Generation and Distribution Systems. In this paper we present an expansion of the previous work in two directions. First, we describe the application of the methodology to the validation of Proximity Sensing Systems (PSS) requirements showing the effectiveness of the method to a new aerospace domain. Second, both the methodology and technology components have been expanded and applied to the PSS to enable automatic generation of test cases from the validated requirements models showing a novel application of formal models…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Power Dissipation Optimization for Solid State Power Control Modules in the Aircraft Secondary Power Distribution System

UTC Aerospace Systems-Neno Novakovic, Milorad Manojlovic
Published 2018-10-30 by SAE International in United States
In the last two decades, an aerospace industry trend in the secondary power distribution concept has been dominated by power electronics technology which includes power converters and Power Control Modules based on Solid State Power Control (SSPC) switching elements. These Power Control Modules, grouped around microprocessor based controllers and combined in a single electronic chassis, have become a backbone of electrical power distribution systems on all major commercial and military transport aircraft. Due to the resistive properties of the semiconductor-based SSPC devices, whose behaviors can be described as nonlinear functions of ambient operating temperature, power distribution system integration with SSPCs is challenged and heavily affected by operating temperatures and power dissipation limits. Although aircraft compartments where Power Control Modules are located are considered temperature and pressure controlled, high ambient operating temperatures are possible and expected. For that reason, Power Control Modules with multiple SSPC channels, at room ambient operating temperature, cannot utilize maximum power capacity, which means that a certain number of power control channels cannot be used for power distribution. As a result of…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Systematic Evaluation of Sulfur Poisoning and Desulfation Behavior for HD Diesel Oxidation Catalysts

UTC Aerospace Systems-Douglas Ummel
Umicore Autocat USA Inc.-Kenneth S. Price, Thomas Pauly
Published 2018-04-03 by SAE International in United States
To enable better matching of Diesel Oxidation Catalyst (DOC) properties to aftertreatment system and application requirements, a systematic evaluation of the effects of sulfur poisoning and desulfation was undertaken on a number of Heavy Duty DOC formulations at representative Platinum Group Metal (PGM) loadings. Uniformly coated DOCs having PGM ratios from 1/0 Pt/Pd to 0/1 Pt/Pd with commercial HDD DOC washcoats were evaluated on a Tier 3 Non-Road engine. In addition, a new DOC formulation intended for reduced sulfur sensitivity, a DOC containing zeolite for hydrocarbon (HC) adsorption, and a layered DOC containing both high and low Pt/Pd ratio layers were compared. Two levels of PGM loading were included for three of the uniform sample formulations. The primary evaluation was through a series of light - off tests under which the NO2 make by oxidation of NO, and the HC and CO oxidation efficiency were observed, quantifying the expected increased sensitivity to poisoning as the Pt/Pd ratio decreases. The catalysts were evaluated as hydrothermally aged to a full useful life reference aging, after being sulfur…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Data Fusion Techniques for Object Identification in Airport Environment

UTC Aerospace Systems-Kiran Thupakula
Published 2017-09-19 by SAE International in United States
Airport environments consist of several moving objects both in the air and on the ground. In air moving objects include aircraft, UAVs and birds etc. On ground moving objects include aircraft, ground vehicles and ground personnel etc. Detecting, classifying, identifying and tracking these objects are necessary for avoiding collisions in all environmental situations. Multiple sensors need to be employed for capturing the object shape and position from multiple directions. Data from these sensors are combined and processed for object identification.In current scenario, there is no comprehensive traffic monitoring system that uses multisensor data for monitoring in all the airport areas. In this paper, for explanation purposes, a hypothetical airport traffic monitoring system is presumed that uses multiple sensors for avoiding collisions. The referenced system employs multiple types of sensors for object data collection in different situations, wherein the collected multi object data is combined to classify and identify the objects, and identified objects are accurately tracked for collision prediction.This paper discusses a data fusion model of multisensor data for object identification in an airport environment…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Method of Reporting and Prioritizing Faults for Aircraft Downtime Reduction

UTC Aerospace Systems-Mohammad Barkat, Vivek Karan, Pradeep N
Published 2017-09-19 by SAE International in United States
The exponential increase in the number of aircrafts and air travelers has triggered new innovations which aim to make airline services more reliable and consumer friendly. Quick and efficient maintenance actions with minimum downtime are the need of the hour. Areas that have a large potential for improvement in this regard are the real time use of diagnostic data, filtering/elimination of nuisance faults and machine learning capabilities with respect to maintenance actions.Although, numerous LRUs installed on the aircraft generate massive amounts of diagnostic data to detect any possible issue or LRU failure, it is seldom used in real time. The turnaround time for LRU maintenance can be greatly reduced if the results of the diagnostics conducted during LRU normal operation is relayed to ground stations in real-time. This enables the maintenance engineers to plan ahead and initiate maintenance actions well before the aircraft lands and becomes available for maintenance. Handling nuisance faults generated during the LRU diagnostic tests is another area with scope for improvement. The advancements in predictive analytics can be harnessed to identify…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Adopting Model-Based Software Design and Verification for Aerospace Systems

UTC Aerospace Systems-Ashutosh Kumar Jha, Prakash Choudhary
Published 2017-09-19 by SAE International in United States
The complexity of software development is increasing unprecedentedly with every next generation of aircraft systems. This requires to adopt new techniques of software design and verification that could optimize the time and cost of software development. At the same time these techniques need to ensure high quality of software design and safety compliance to regulatory guidelines like DO-178C [1] and its supplements DO-330[2] and DO-331[3].To arrive at new technologies one has to evaluate the alternate methods available for software design by developing models, integration of models, auto-code generation, auto test generation and also the performance parameters like time, effort, reuse and presentation needs to be evaluated. We have made an attempt to present summary of alternate design concept study, and edge of MBD over other design techniques.The new techniques have challenges in managing the software development processes through conventional means and showing their compliance to stringent industry standards and guidelines. We have present process compliance to aerospace software development guideline DO-178C.This paper has discussed requirements of DO-178C and its associated supplement DO-331 for model based…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Electromagnetic Compatibility and Interference - Design Methodology, Challenges and Guidelines for Avionics Product and Systems

UTC Aerospace Systems-Prashant S Vadgaonkar, Diptar banik
Published 2017-09-19 by SAE International in United States
Avionics industry is moving towards more electric & lightweight aircrafts. Electromagnetic effects becomes significantly challenging as materials starts moving towards composite type. Traditional methods for controlling EMC will not be sufficient. This shift increases the complexity of in-flight hardware elements for EMI/EMC control.This paper discusses the need for EMI/EMC Control and brings out the analysis & applicability of various EMI/EMC standards in aerospace, commercial and industrial electronic products, provides comparative study with respect to levels. The study include various sections of DO-160 and applicable guidelines for controlling EMI/EMC with respect to LRU (Line Replaceable Unit) & wire/cable harnesses. Also presents guidelines with respect to shielding of components, selection of components, grounding schemes, filter topologies and layout considerations.It provides comparative study made for different filters, good layout examples, generic simulation examples and lessons learnt from the failures. An attempt is made to propose the design methodology to be adapted for successful design for Electromagnetic effects.This paper puts forth the various challenges like size constraints, isolation requirements, component shielding, cost of EMI filters, weight, layout of- high…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Framework and Platform for Next Generation Aircraft Health Management System

UTC Aerospace Systems-Ashutosh Kumar Jha, Gaurav Sahay, Adishesha Sivaramasastry
Published 2017-09-19 by SAE International in United States
In aerospace industry, the concept of Integrated Vehicle Health Management (IVHM) has gained momentum and is becoming need of the hour for entire value chain in the industry. The expected benefits of lesser time for maintenance reduced operating cost and ever busy airports are motivating aircraft manufacturers to come up with tools, techniques and technologies to enable advanced diagnostic and prognostic systems in aircrafts.At present, various groups are working on different systems and platforms for health monitoring of an aircraft e.g. SHM (Structural Health Monitoring), PHM (Prognostics Health Monitoring), AHM (Aircraft Health Monitoring), and EHM (Engine Health Monitoring) and so on. However, these approaches are mostly restricted to federated architecture where faults and failures for standalone line replaceable units (LRUs) are logged inside the unit in fault storage area and are retrieved explicitly using maintenance based applications for fault and failure diagnostics. With the transformational growth in computing technology, one can easily visualize the possibilities of moving from present federated architecture to integrated architecture for health monitoring of aircraft in near future.The advanced analytical methods…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Method for Analytical Calculation of Harmonic Content of Auto-Transformer Rectifier Units

UTC Aerospace Systems-Joshua Parkin
RWTH Aachen University-Rolf Loewenherz
Published 2016-09-20 by SAE International in United States
Auto transformer rectifier units (ATRUs) are commonly used in aircraft applications such as electric actuation for harmonic mitigation due to their high reliability and relative low cost. However, those components and the magnetic filter components associated to it are the major contributors to the overall size and weight of the system. Optimization of the magnetic components is essential in order to minimize weight and size, which are major market drivers in aerospace industry today. This requires knowledge of the harmonic content of the current. This can be obtained by simulation, but the process is slow. In order to enable fast and efficient design space exploration of optimal solutions, an algebraic calculation process is proposed in this paper for multi-pulse ATRUs (e.g. 12-pulse and 18-pulse rectifiers), starting from existing solution proposed for 6 pulse rectifier in the literature. The method consists of mapping AC and DC sides of a balanced 6N-Pulse system into the sum of equivalent 6-Pulse systems. This problem can then be solved with available methods, and then the AC and DC currents are…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Lightweight Spatio-Temporally Partitioned Multicore Architecture for Concurrent Execution of Safety Critical Workloads

UTC Aerospace Systems-Christopher Noll, Eelco Scholte
University of Connecticut-Qingchuan Shi, Kartik Lakshminarashimhan
Published 2016-09-20 by SAE International in United States
Modern aircraft systems employ numerous processors to achieve system functionality. In particular, engine controls and power distribution subsystems rely heavily on software to provide safety-critical functionality, and are expected to move toward multicore architectures. The computing hardware-layer of avionic systems must be able to execute many concurrent workloads under tight deterministic execution guarantees to meet the safety standards. Single-chip multicores are attractive for safety-critical embedded systems due to their lightweight form factor. However, multicores aggressively share hardware resources, leading to interference that in turn creates non-deterministic execution for multiple concurrent workloads. We propose an approach to remove on-chip interference via a set of methods to spatio-temporally partition shared multicore resources. Our proposed partitioning scheme is bounded within the worst case execution, and ensures efficient performance and deterministic execution.
Annotation ability available