Air Control System Research Articles

Building cabin air control system with Green Hills Software

Building cabin air control system with Green Hills Software

Responsiveness Improvement of Idling Speed Control for Automotive Using SMC

To improve the responsiveness of engine speed control to disturbances, robust controls were investigated by simulation. The intake air control system of a gasoline engine is a typical nonlinear system, and the disturbances and parameter perturbations are generally regarded as being the unstable factors with regard to engine control. In this paper, a Mean-Value Engine Model (MVEM) with disturbances and parameter perturbations is investigated using Sliding Mode Control (SMC), which is a form of variable structure control, with a view to address instability in the idle speed control process. The simulation results confirmed that, compared with a conventional PI (Proportional-Integral) controller, the stability of the idle speed for an engine that is being subjected to disturbances, parameter variations and background noise is greatly improved by the application of SMC.

Fuel Injection Systems of Marine Large Low Speed Diesel Engines

The fuel injection system is one of the most important parts of the diesel engine. In this paper, it reports the history and features of fuel injection systems which were installed on the modem typed marine large two strokes cycle low speed diesel engines. The famous recent three brands have been adopted different typed fuel injection systems on their diesel engines. One is good controllable type, another is simple construction. What did the engineers consider when they developed them?Recently, the fuel injection is controlled by electronic devices. The control ability is increased and we can control not only fuel injection but also fuel oil consumption, NOx emission and smoke. The electronic control fuel injection system removed mechanical devices such as gear train, cam and roller, camshaft, linkage and governor from the diesel engine. This movement is influenced to the exhaust valve driving system, starting air control system and cylinder lubricating system which were moved by the camshaft. The diesel engine will change more from the fuel injection system.

Dissection of the high velocity air control (HVAC) system serving the in vitro fertilization (IVF) laboratory: the impact of ultraviolet-c band (UVC) irradiation on clinical pregnancy rates (CPR)

Successful preimplantation embryogenesis (pe) is critically dependent upon the culture environment and changing organic chemistry of the ambient air (aa) provided by the IVF laboratory. The HVAC system serving the IVF laboratory plays a key role in controlling aa quality. Its design and maintenance is critical as it can serve as both the source of and perfect conduit for the spread of embryotoxic bioaersols and microorganisms. Placement of UVC light sources within the HVAC system will kill pathogens threatening the aa.

Design of a Smart Gas Sensor System for Room Air-Cleaner of Automobile (Thick-Film Metal Oxide Semiconductor Gas Sensor)

It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

Conducting large-scale multi-user user tests on the United Kingdom air defence command and control system

IBM was contracted to provide a new Air Defence Command and Control (ADCC) system for the Royal Air Force. The IBM Human Factors (HF) team was responsible for the design of the operations room, wor...

레이더 자료를 이용한 항적추적관리시스템 설계 및 구현

Radars are used to detect the motion of the low flying enemy planes in the military. Radar-detected raw data are first processed and then inserted into the ground tactical C4I system. Next, these data we analyzed and broadcasted to the Shooter system in real time. But the accuracy of information and time spent on the displaying and graphical computation are dependent on the operator`s capability. In this paper, we propose the Flying Object Tracking Management System that allows the displaying of the objects` trails in real time by using data received from the radars. We apply the coordinate system translation algorithm, existing communication protocol improvements with communication equipment, and signal and information computation process. Especially, radar signal duplication computation and synchronization algorithm is developed to display the objects` coordinates and thus we can improve the Tactical Air control system`s reliability, efficiency, and easy-of-usage.

Wärtsilä - Haldor Topsøe SOFC Test System

In this paper, the design and construction of a 1 - 5 kW SOFC test system is presented together with initial test results obtained during the first 1080 hours of operation. The main purpose of the test system is to analyse and demonstrate a complete SOFC system including fuel and air supply systems, heat exchangers, fuel processing units, power electronics etc., as well as be a platform for testing and evaluation of individual BoP components. The study describes basic design criteria and properties of the test system. Characteristics of major sub-systems such as fuel and air supply, steam supply, purge gas, exhaust heat-recovery, power electronics and control system are also explained. The system will be used for system testing and modelling purposes for several years to come. It will also support product development and designing of an upcoming alpha-prototype and other prototype units.

Potential Contributions of Rough Sets Data Analysis to Training Evaluations

Effective training evaluation presents many challenges to the researcher and practitioner. We introduce rough sets theory and analysis as an analytic tool that can be employed to evaluate training systems effectively. The technique is especially helpful if any of the following situations exist in evaluating the training context: Data are discrete, relations among or between predictor and criterion variables are nonlinear, it is important to be able to determine the relative importance of predictor variables, or the concept describing the training criterion changes one or more times throughout the training pipeline. The technique is applied to data taken from a high-fidelity training simulator used by Air Force Airborne Warning and Control System (AWACS) teams. Both team- and position-level findings are presented. The discussion highlights the strengths and limitations of the approach.

Clean Stocker내 새로운 방식의 기류제어에 관한 해석

Clean stockers are being used by semiconductor and TFT-LCD manufacturers to store and buffer work in process. The only way to keep the stored product clean is to provide constant clean airflow the product and through stocker. Up to now, stockers typically have been configured to receive their laminar airflow from fan filter units that are located on the side of the stocker. This type of stocker may have such problems as complexity of structure, increment of temperature, mechanical vibration, initial investment and running cost. In this study, in order to solve the above mentioned problems, new air control system in stocker is proposed, which is to control open ratios of exits that are located on the side of the stocker without fan filter units. In this study, static pressure regain was used for the analysis of the open ratios of exits theoretically and experiment was also conducted using actual clean stocker for TFT-LCD manufacturers and CFDesign, was used for simulating airflow in stocker. As a result, open ratios of exits can be obtained by the analysis of static pressure regain and was verified by experiment and simulation results. Therefore, new air control system in stocker can be used by the semiconductor and TFT-LCD manufacturers.

Single unit responses of human cutaneous mechanoreceptors to air-puff stimulation

Objective: To investigate responsiveness of human cutaneous mechanoreceptor to selective tactile stimuli produced by brief air-puff stimulation. Methods: Using percutaneous microneurography, activities of single sensory units innervating glabrous skin of the hand were recorded, and air-puff stimuli with a short rise time (0.5 ms), generated by a high-speed air control system, were applied to the receptive field. Receptor activation time was estimated as the latency difference between electrically and air-puff evoked responses. Results: Thirty units were analyzed: all 4 kinds of mechanoreceptors of human glabrous skin (fast adapting type 1 [FA I, n=7], fast adapting type 2 [FA II, n=4], slowly adapting 1 [SA I, n=5] and slowly adapting 2 [SA II, n=14]) were activated by air-puff stimulation. Estimated receptor activation times were 0.6–6.2 ms (mean 2.2 ms). FA II units occasionally responded twice or more to a single air-puff stimulus. Conclusions: Brief air-puffs can activate all 4 human cutaneous mechanoreceptors, and the receptor transduction time is estimated as approximately 2.0 ms. Properties of human mechanoreceptors can be studied using air-puff stimulation and microneurography.

Analytical Method for the Prediction of Reliability and Maintainability Based Life-Cycle Labor Costs

An analytical method for predicting life-cycle maintainability labor costs is developed. The purpose of the analytical method is to allow the evaluation of products, based on life-cycle labor costs, early in the design process. The Boeing 737-300/400/500 Bleed Air Control System is used as a test model, and the results of the analysis are compared with historical data for this system. Four prospective design changes to the Bleed Air Control system are analyzed to demonstrate the ability of the analytical method to evaluate and compare differing designs or design changes.

Influence of the Nuclei on the Cavitation Inception for Different Types of Cavitation on Ship Propellers

In order to relate nuclei size distributions with inception cavitation in cavitation facilities, a test program was conducted at the Grand Tunnel Hydrodynamique (GTH) of the Bassin d’Essais des Care`nes. The GTH, which has a complete air control system including dissolved gas and nuclei (microbubbles) control, offers the opportunity to answer this question. The tests were conducted on the three 34 mm diameter propellers used by Kuiper (1981), each of these propellers being characterized by a different cavitation type: bubble, sheet and vortex cavitation. The water nuclei content correspond to strong degassed water (maximum tension), low injection of medium size nuclei (medium tension-low content), large injection of medium size nuclei (medium tension-high content) and large injection of large nuclei (minimum tension). By injecting medium size nuclei for a low content and a high content, we can examine the influence of the number of nuclei on the cavitation inception characteristic. During all the tests, the dissolved air content was kept constant. The GTH online Cavitation Nuclei Counter (Centerbody Venturi) was used to measure both the water nuclei distribution and the liquid tension. Comparisons are made with the calibrated Centerbody Venturi, a Phases Doppler Particles Analyzer (PDPA) and Holographic measurements.

Reliability centered prediction technique for diagnostic modeling and improvement

A diagnosability prediction metric is developed for system modeling of component failure rates and unjustified removals. The metric emphasizes ambiguity of system component indications as well as system structure. The metric is evaluated using historical data from the bleed air control system (BACS) on the Boeing737-300. Four design changes are suggested based on improving system diagnosability by changing component functions, modifying indications, and adding or changing sensors. The resulting designs are compared via Boeing's life cycle cost mechanism, DEPCOST model, based on cost improvements. It is shown that system improvements based on this prediction technique will increase the quality of a product since increased diagnosability decreases life cycle costs.

Diagnostic Modeling and Diagnosability Evaluation of Mechanical Systems

Consideration of diagnosability in product design promises to increase product quality by reducing maintenance time without increasing cost or decreasing reliability. Methods for investigating the diagnosability of mechanical and electro-mechanical systems are described and are applied to the Bleed Air Control System (BACS) on the Boeing 747-400. The BACS is described and a diagnostic model is developed using information from the system Failure Modes and Effects Analysis. Emphasis is placed on the relationships between the system’s functions and its components. Two metrics for the evaluation of system diagnosability and two metrics for the evaluation of component diagnosability are defined. These metrics emphasize diagnostic ambiguity and are combined with the probability of different system failures to weight the effects of each failure. Three modified systems are produced by reassigning functions from one component to another. The resulting effects on the system and component diagnosability are evaluated. We show that by changing these relationships system diagnosability can be improved without adding sensors or other components.

Specification and validation of a security policy model

The paper describes the development of a formal security policy model in Z for the NATO Air Command and Control System (ACCS): a large, distributed, multilevel-secure system. The model was subject to manual validation, and some of the issues and lessons in both writing and validating the model are discussed. >

DGPSによる空港面監視システムの基礎実験

Conventional air traffic control system have great difficulties in surveying aircraft and vehicles that are moving on the airport surface under bad weather conditions, for example in thick fog, or at night. To solve this problem, the authors have been studying the possibility of introducing differential GPS (DGPS) for air control systems. We have completed an experimental system to verify the positioning accuracy of a control system with DGPS. An experiment was carried out on vehicles incorporating this system at Sendai Airport. The experiment showed that the DGPS positioning accuracy at a fixed point was 0.7m (1-sigma) , and lateral deviation on a moving-test along a straight line was 0.6m (1-sigma). Experimental results also revealed that positioning errors increased when satellites were masked by buildings or other obstacles.

Automation and Supervisory Control: A Perspective on Human Performance, Training, and Performance Aiding

This paper is based on results from an on-going effort sponsored by the US Army Research Institute (ARI) concerned with human performance and training issues in automated, near-real-time air defense command and control systems. Air defense command and control is the specific applications context, but the paper's implications extend to many contemporary process control settings. Topics that are addressed in the paper include: (1) human performance problems associated with automation, (2) a new look at human performance requirements in near-real-time process control, (3) and training and job performance support requirements for supervisory controllers. The “new look” portion describes a reasonable and evolving concept for human participation in automated processing, designated Rule-Based Supervisory Control. The paper is intended to introduce these topics to concept developers, system designers, and trainers dealing with automated process control technology.

The US Army's New Air Defense Command and Control System: The Human Factors Design Process

TRW is currently under contract to produce the US Army's new Command, Control, and Intelligence (C2I) system for its forward areas air defense elements. The system design is characterized by automatic dissemination of tactical aircraft data as well as battlefield intelligence information. The Human Factors Engineering effort on this program has been responsible for all aspects of the design of the operator interface. The effort has focused attention on the value of interactive prototypes for the purpose of detailed design. This paper describes the Human Factors design process on this program and presents a two-phase approach to a rapid prototyping effort. Future plans to use objective data collected from prototype work in conjunction with a formal task analysis are also discussed.

Trigeminal evoked potentials following brief air puff: enhanced signal-to-noise ratio.

Trigeminal somatosensory evoked potentials (TSEPs) were studied by using fast-rising air puffs generated by a high-speed air control system. Within 100 ms, air puff stimulation of the face elicited three negative and three positive components over the contralateral, as well as the ipsilateral, sensory area. The air puff TSEPs showed a uniform change in peak latencies and amplitudes as a function of stimulus intensity. The bilateral distribution of the TSEPs stands in sharp contrast to the exclusively contralateral distribution of the SEPs to stimulation of the hand. Air puffs evoked a larger response than electrical stimulation, although the latency remained the same. Unlike electrical stimuli, air puff induces neither stimulus nor muscle artifacts. This, combined with the higher amplitude of the recorded response, enhances the signal-to-noise ratio.