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SCR Deactivation Study for OBD Applications

2012-06-18
Selective catalytic reduction (SCR) catalysts will be used to reduce oxides of nitrogen (NOx) emissions from internal combustion engines in a number of applications [1,2,3,4]. Southwest Research Institute® (SwRI)® performed an Internal Research & Development project to study SCR catalyst thermal deactivation. The study included a V/W/TiO2 formulation, a Cu-zeolite formulation and an Fe-zeolite formulation. This work describes NOx timed response to ammonia (NH3) transients as a function of thermal aging time and temperature. It has been proposed that the response time of NOx emissions to NH3 transients, effected by changes in diesel emissions fluid (DEF) injection rate, could be used as an on-board diagnostic (OBD) metric. The objective of this study was to evaluate the feasibility and practicality of this OBD approach.
Journal Article

Driving Simulator Performance in Charcot-Marie-Tooth Disease Type 1A

2019-05-10
Abstract Introduction: This study evaluates driving ability in those with Charcot Marie Tooth Disease Type 1A, a hereditary peripheral neuropathy. Methods: Individuals with Charcot Marie Tooth Disease Type 1A (n = 18, age = 42 ± 7) and controls (n = 19; age = 35 ± 10) were evaluated in a driving simulator. The Charcot Marie Tooth Neuropathy Score version 2 was obtained for individuals. Rank Sum test and Spearman rank correlations were used for statistical analysis. Results: A 74% higher rate of lane departures and an 89% higher rate of lane deviations were seen in those with Charcot Marie Tooth Disease Type 1A than for controls (p = 0.005 and p < 0.001, respectively). Lane control variability was 10% higher for the individual group and correlated with the neuropathy score (rS = 0.518, p = 0.040), specifically sensory loss (rS = 0.710, p = 0.002) and pinprick sensation loss in the leg (rS = 0.490, p = 0.054).
Standard

Standard Scenarios and Examples of Operation of Airborne Wake Vortex Safety Systems

2013-11-26
WIP
AIR6288
This document describes operational scenarios and examples of system operation based on the experience of different developers of airborne wake vortex safety systems. This information is intended to supplement the recommendations and guidance given in ARP 6267 “Airborne Wake Vortex Safety Systems” as well as facilitate the application of other wake vortex standards and guidance documents generated by SAE and RTCA.
Standard

Display Latency Evaluation Procedures

2012-12-03
WIP
ARP6238
This Aerospace Recommended Practice will identify the problem with latency in the pilot's instrument control of an aircraft. Recommended evaluation techniques to characterize control problems will be documented.
Standard

AIRBORNE WAKE VORTEX SAFETY SYSTEMS

2013-03-26
WIP
ARP6267
This document recommends criteria for Airborne Wake Vortex Information Systems, including operational objectives, characteristics, and functional requirements. The recommendations in this document apply to transport aircraft, and describe the operational objectives of wake vortex information systems, situational displays, guidance systems, and avoidance/detection systems.
Standard

Human Engineering Considerations with Implementation of Aided Flight Vision forVertical Flight Platforms All Weather Operations

2018-12-14
WIP
ARP8459
Identify the phase of flights that can take benefit of Aided Visual Flight for the various missions of helicopters both VFR and IFR such as: Commercial Air Transport Operations offshore and onshore, EMS (Air ambulance), Law enforcement (Operations with Specific Approvals),Search and Rescue (SAR) operations both in Maritime and Mountainous operations The Aided Flight should be considered with various levels of on-boarded sensor technology and its performance such as, but not limited to: NVG, Addition of Axial IR Sensor (with minimum performance to define), Potential use of orientable search light (night VFR) and other situation awareness means like HTAWS, SVS, and sensor like Radio Altimeter including the display mean head-down or head worn that influence operational aspects.
Journal Article

Development of Vehicle HMI Module Using Model-Based Design and RCP

2009-04-20
2009-01-1415
LCDs are effective to display abundant information in a compact space. Therefore, the use of TFT or DOT metric displays in dashboard instrument display is getting popular in recent years. However, it is important issue for car makers how to let users know information about vehicle functions or outside environment and manage plentiful information. In this paper, the Rapid Control Prototyping (RCP) tool is proposed to design and standardize HMI logic associated with display contents in TFT or dot type LCD applied to an instrument cluster. In addition, it is possible to estimate HMI logic in advance by using this RCP. By this process, we can minimize the design and validation time of the vehicle specific HMI logic and improve the quality. As a result, we can dramatically reduce the total period of developing an instrument cluster.
Journal Article

Reconstruction of Time-Resolved Vehicle Emissions Measurements by Deconvolution

2009-04-20
2009-01-1513
A thorough understanding of vehicle exhaust aftertreatment system performance requires time-resolved emissions measurements that accurately follow driving transients, and that are correctly time-aligned with exhaust temperature and flow measurements. The transient response of conventional gas analyzers is characterized by both a time delay and an attenuation of high-frequency signal components. The distortion that this imposes on transient emissions measurements causes significant errors in instantaneous calculations of aftertreatment system efficiency, and thus in modal mass analysis. This creates difficulties in mathematical modeling of emissions system performance and in optimization of powertrain control strategies, leading to suboptimal aftertreatment system designs. A mathematical method is presented which improves the response time of emissions measurements. This begins with development of a model of gas transport and mixing within the sampling and measurement system.
Journal Article

Thermal Analysis of Urea Tank Solution Warm Up for Selective Catalytic Reduction (SCR)

2009-04-20
2009-01-0971
Due to the stringent requirements to reduce the tail pipe emissions of NOx, Selective Catalytic Reduction (SCR) systems are used to remove NOx using ammonia. When a urea solution is injected into the exhaust system, urea will undergo hydrolysis and decomposition reaction that produces ammonia. At the catalyst surface, ammonia will react with the exhaust gases to convert NOx into nitrogen, N2 and water, H2O. One of the challenging problems is to make sure the urea solution is available for the SCR system at cold start conditions. At extreme cold temperatures, the urea solution will begin to freeze at −12°C. At the start up of a vehicle under such low ambient temperatures, a heating system is used to provide the heat required for melting the frozen urea. Therefore, there will be a time lag between the vehicle start up and the availability of urea solution to the SCR system.
Standard

Statement on Requirements for Real-Time Communication Protocols (RTCP)

2011-11-15
HISTORICAL
AIR4886
The purpose of this document is to establish the requirements for Real-Time Communication Protocols (RTCP). Systems for real-time applications are characterized by the presence of hard deadlines where failure to meet a deadline must be considered a system fault. These requirements have been driven predominantly, but not exclusively, by aerospace type military platforms and commercial aircraft, but are generally applicable to any distributed, real-time, control systems. These requirements are primarily targeted for the Transport and Network Layers of peer to peer protocols, as referenced in the Open System Interconnect Reference Model (2.2.1 and 2.2.2), developed by the International Standards Organization (ISO). These requirements are intended to complement SAE AS4074 (2.1.1) and AS4075 (2.1.2), and future SAE communications standards.
Standard

Statement on Requirements for Real-Time Communication Protocols (RTCP)

2016-10-21
CURRENT
AIR4886A
The purpose of this document is to establish the requirements for Real-Time Communication Protocols (RTCP). Systems for real-time applications are characterized by the presence of hard deadlines where failure to meet a deadline must be considered a system fault. These requirements have been driven predominantly, but not exclusively, by aerospace type military platforms and commercial aircraft, but are generally applicable to any distributed, real-time, control systems. These requirements are primarily targeted for the Transport and Network Layers of peer to peer protocols, as referenced in the Open System Interconnect Reference Model (2.2.1 and 2.2.2), developed by the International Standards Organization (ISO). These requirements are intended to complement SAE AS4074 (2.1.1) and AS4075 (2.1.2), and future SAE communications standards.
Journal Article

Practical Approach to Develop Low Cost, Energy Efficient Cabin Heating for Extreme Cold Operating Environment

2011-04-12
2011-01-0132
In cold climatic regions (25°C below zero) thermal comfort inside vehicle cabin plays a vital role for safety of driver and crew members. This comfortable and safe environment can be achieved either by utilizing available heat of engine coolant in conjunction with optimized in cab air circulation or by deploying more costly options such as auxiliary heaters, e.g., Fuel Fired, Positive Temperature Coefficient heaters. The typical vehicle cabin heating system effectiveness depends on optimized warm/hot air discharge through instrument panel and foot vents, air directivity to occupant's chest and foot zones and overall air flow distribution inside the vehicle cabin. On engine side it depends on engine coolant warm up and flow rate, coolant pipe routing, coolant leakage through engine thermostat and heater core construction and capacity.
Journal Article

Design and Characterization of an E-booster Driven by an High Speed Brushless DC Motor

2013-04-08
2013-01-1762
Engine downsizing has become one of the main strategies to reduce C02 emission. Turbochargers are well-adapted to this purpose but one of their biggest drawbacks is the turbo-lag which reduces the driving comfort especially during acceleration. Electrically driven compressors also known as E-compressor or E-booster could be a well-adapted solution to boost the engine intake pressure in order to reduce the turbo-lag. Since centrifugal compressors operate at high rotational speeds, high speed electric machines are therefore required. To achieve a significant reduction of the turbo-lag, a very fast response time is needed leading to the development of electric machines able to typically spin from idle to 75kRPM in less than 300ms. With 20 years of expertise in the development of innovative brushless DC motors for automotive applications, MMT has recently investigated the design of such high power-high rotation speed motors.
Journal Article

Modeling, Experimentation and Sensitivity Analysis of a Pneumatic Brake System in Commercial Vehicles

2014-04-01
2014-01-0295
The main purpose of this research is to investigate the optimal design of pipeline diameter in an air brake system in order to reduce the response time for driving safety using DOE (Design of Experiment) method. To achieve this purpose, this paper presents the development and validation of a computer-aided analytical dynamic model of a pneumatic brake system in commercial vehicles. The brake system includes the subsystems for brake pedal, treadle valve, quick release valve, load sensing proportional valve and brake chamber, and the simulation models for individual components of the brake system are established within the multi-domain physical modeling software- AMESim based on the logic structure. An experimental test bench was set up by connecting each component with the nylon pipelines based on the actual layout of the 4×2 commercial vehicle air brake system.
Journal Article

Self-Regulation Minimizes Crash Risk from Attentional Effects of Cognitive Load during Auditory-Vocal Tasks

2014-04-01
2014-01-0448
This study reanalyzes the data from a recent experimental report from the University of Utah investigating the effect on driving performance of auditory-vocal secondary tasks (such as cell phone and passenger conversations, speech-to-text, and a complex artificial cognitive task). The current objective is to estimate the relative risk of crashes associated with such auditory-vocal tasks. Contrary to the Utah study's assumption of an increase in crash risk from the attentional effects of cognitive load, a deeper analysis of the Utah data shows that driver self-regulation provides an effective countermeasure that offsets possible increases in crash risk. For example, drivers self-regulated their following distances to compensate for the slight increases in brake response time while performing auditory-vocal tasks. This new finding is supported by naturalistic driving data showing that cell phone conversation does not increase crash risk above that of normal baseline driving.
Journal Article

Impact of Control Methods on Dynamic Characteristic of High Speed Solenoid Injectors

2014-04-01
2014-01-1445
Accurate control of both the timing and quantity of injection events is critical for engine performance and emissions. The most serious problem which reduces the accuracy of the control operation in such systems is a time delay of the responsiveness for the opening and closing operation of the electromagnetic valve. Modern electronic control systems should be capable of driving high speed solenoid injectors at a very fast switch frequency with high efficiency and acceptable power requirements. In this paper, the dynamic characteristic of a high speed servo-hydraulic solenoid injector for diesel engine, with different driving circuits and control methods, is investigated. A pre-energizing control strategy based on a dual power supply is applied to speed up the opening response time of the injectors.
Technical Paper

Prediction of Biodiesel Production from Sardine Fish Oil Methyl Ester Using Microwave Assisted Transesterification Method Using Response Surface Methodology

2021-09-21
2021-01-1202
This study presents a demonstration of generating biodiesel from fish oil utilising microwave with a significant reduction in the amount of catalyst needed during the reaction and the time of reaction. Various factors such as microwave power, catalyst concentration, reaction duration, and molar ratio were tested experimentally. The response surface approach was used to improve the reaction parameters. As reaction parameters, four levels were chosen: molar ratio, catalyst concentration, and reaction time. According to the RSM model results, molar ratio has a crucial role in the transesterification of fish oil to bio diesel. Confirmatory tests were carried out to validate the acquired data, and they proved to be worthwhile.
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