Airborne Electronic Equipment Research Articles

A LIFE CYCLE MODEL FOR THE DEVELOPMENT OF AIRBORNE ELECTRONIC EQUIPMENT

This paper describes a life cycle model for the development of electronic equipment for use on board military aircraft in the South African context. The life cycle model presented consolidates the activities of systems engineering, safety and certification, and quality assurance. The life cycle model provides a clear-cut and comprehensive framework for the development process in order to streamline planning and control. Concepts fundamental to the definition of a development process are identified and explained, and a generalised life cycle model is derived. Applications of this life cycle model in the description of development processes for airborne electronic equipment are presented.

Flight experiments and failure analysis of FPGA for anti-SEU at aviation altitudes

With the development of microelectronics technology, small size, high integration density and low voltage devices are increasingly used in avionics. Many researchers found that the particle radiation caused by the charged particles in upper atmosphere have a significant impact on avionic devices. In consideration of the potential safety hazard by single event upsets and the urgent demand of airborne equipment localization, this paper reports the research and analysis of the single event upset problems of FPGA devices applied in the airborne electronic equipment. Firstly, the flight experimental data of mainstream FPGAs at the aviation flight altitudes are analyzed. Then, further demonstration is made about whether these FPGA devices meet the needs of civil aviation. The analysis results show that single event upset is an indispensable problem according to the conditions of mainstream FPGA chip with the small size and working voltage. Even the FPGA devices are working at the air flight altitude or near the ground, the failure caused by single event upset would make them unable to meet the safety requirements of civil aviation equipment.

Dynamics Simulation Analysis of an Airborne Electronic Equipment Based on Ansys and Modal Test

In order to conduct dynamics simulation analysis on an airborne electronic equipment, total mass equivalent method is used to simplify the finite element model of electronic building brick. Considering this method’s disadvantage that it does not take into account the effect which the components have on stiffness of the printed circuit board(PCB), the modal test technique is carried out to recify the model and generate the equivalent stiffness of the substrate. Then the modal analysis and random vibration analysis are performed on the complete machine, calculating more accurate dynamics simulation results which provide a reliable qualitative basis for improving the vibration-proof design of the equipment.

Research on the Applications of Heat Pipes in Cooling Aircraft Electrical Equipment

In order to ensure proper temperatures for electronic equipment and to meet the increasing heat dissipation capacity needs of airborne electronic equipment, a suitable heat-pipe for use in aircraft equipment needs to be found. Considering both the acceleration and the changes in tilt angle of the aircraft, performance analysis of five main types of heat-pipes showed that dual compensation chamber loop heat pipe and micro-channel plate heat pipe were the most suitable for use in airborne electrical equipment.

Virtual Maintenance Training System of Airborne Electronic Equipment

Maintenance training of airborne electronic equipment is the guarantee of working orderly for the airplane. The best choice of maintenance training is using real electronic equipment so that high training cost and potential damage to normally working equipment exist. To reduce the training cost and risk, a virtual maintenance training system of airborne electronic equipment is designed and implemented using virtual reality technology. The architecture of this virtual training system is given. In this architecture, three-dimensional model of electronic equipment is implemented by 3DMax software, and GL Studio software is used to create the operation response of all manipulations. Signal models based on multi signals flaw graph is used to simulate various faults. Finally, the application of this virtual maintenance training system in daily aircraft maintenance training show good training efficiency.

Designing and Realizing of Universal Test and Analysis System of Avionics Data Bus

In modern combat aircrafts, avionics integrated systems play an increasingly important role. Bus test and analysis system is used as a testing platform for the testing, debugging, maintenance and monitoring of airborne electronic equipment, which could rapidly detect and identify the working status of the bus. This paper discusses the general avionics data bus test system design and implementation, which focuses on the test system design, system management, software development, and the bus information flow management of the whole system. The universal test and analysis system is based on the bus test analysis platform of ICD database that can effectively test ARINC429 bus and 1553B bus. Through integrating the platform into the simulation system, it can complete the closed-loop test of the integrated avionics simulation test system, analyze the state changes of various information flows during the process of bus communication, test and verify the active status and logical sequence of avionic fire control test systems, which has achieved very good results in the practical engineering applications.

An Airborne Electronic Equipment Life Prediction Method Based on Normal Distribution Fitting

 Abstract—According to the current status that the Civil Aviation Industry lack of effective method for airborne electronic equipment life prediction. Based on studying characteristic parameters of the airborne electronic equipment lifecycle, this paper analyzes some real service data of airborne electronic equipment, and then use airborne electronic equipment life prediction method which based on normal distribution fitting, study the life distribution of series components with the same part number, and gives the confidence interval of the overall mean and variance in the 0.9 confidence level. Index Terms—Airborne electronic equipment, life prediction, normal distribution fitting, confidence interval Airborne electronic equipment is repairable product, It can be used in the cycle of use-repair-use, and most of the components are no depletion period. Most of the failures in the service life are randomly. If the airborne electronic equipment faults, it will cause great economic loss and casualty, even a major accident. Life is an important indicator of the airborne equipment running condition, and the current civil aviation industry lack of an effective method for airborne electronic equipment life prediction. Broadly speaking, according to the theory of reliability engineering, life is one of the reliability parameters of the product. It involves the safe, reliable, economic, and other factors. Due to the longer life of airborne electronic equipment, and most of the products does not exist a significant depletion period, life prediction of no suitable can be monitored depletion parameters and performance degradation parameters, while the airborne electronic products is repairable products, does not give the total life, but only gives the mean time between failures(MTBF) generally. Therefore, this paper analyzes some real service data of airborne electronic equipment, then use airborne electronic equipment life prediction method which based on normal distribution fitting.

Numerical Simulation of Coupling Heat Transfer in Sealed Airborne Electronic Equipments

For shielding radio frequency and electromagnetic interference, the sealed case is usually used for airborne electronic equipment. As electronic products become faster and incorporate greater functionality, their thermal characters must be well analyzed and designed. Three-dimensional thermal numerical simulations from inside to outside of the sealed case were performed to get a clear sight of the coupling heat transfer in conduction, natural convection, and radiation. Temperature field, fluid flow field, and local heat transfer coefficient layout outside the wall were got, which were compared with the outcomes of the empirical method. The results of numerical simulation showed that in sealed case conduction was the dominant way, and natural convection had the comparative ratio with radiation, both of them were less than 25%. The maximum error of no radiation including could get to 43.2%.

2D transient natural convection in diode cavities containing an electronic equipment with discrete active bands under constant heat flux

The thermal behavior of airborne electronic equipment submitted to natural convection in closed parallelogrammic air-filled cavities is examined in this study. The cold active wall of the enclosure is maintained isothermal. The hot wall, representing the electronic device, is composed of three parallel discrete bands generating a constant heat flux, separated by two adiabatic bands of equal dimensions. Both walls remain always vertical. The channel is considered adiabatic and the aspect ratio of the cavity is equal to unity. Many configurations are examined while varying the inclination angle of the top and bottom walls of the channel. When the angle is positive the convective heat transfer is favored in comparison with the case of the right cavity, but, on the contrary, it is reduced for negative angles. The resultant enclosures are so called diode cavities in the convective heat transfer sense of the word. The experimental part of the study is achieved with a setup based on electrical data and temperature measurements on the walls. The numerical approach using the finite volume method allows to complete the experimental results with the thermal and dynamical characteristics of the 2D flow. The temperature fields show the thermal behavior of the device during the transient phase after switching it on. The convective results concerning the imposed heat flux treated in this study differ from those corresponding to impose the temperature on the hot bands. The distribution and evolution of the Nusselt number allow to characterize the natural convection occurring in the cavity. The results of this work are consistent with previous studies and allow to predict the thermal behavior of the electronic equipment during the transient phase.

The Design for Airborne Electronic Equipment Fault Diagnostic System Base on IPC

The Design for Airborne Electronic Equipment Fault Diagnostic System Base on IPC

Research on a New Cooling System of Airborne Electronic Equipment

In order to solve centralized installation and cooling problems of airborne electronic equipment with big power and high heat flow density in aircraft, the paper put forward an innovative closed-loop forced ventilation cooling system, expatiated system compositions and operation principles, and also took a cabinet system for example to introduce new cooling system design method and simulation results.

Aircraft EWIS Electromagnetic Interference wiring Research

A majority of EMI of airborne electronic equipment result from serious electromagnetic coupling caused by improper wiring of aircraft EWIS [1]. Based on detailed analysis of the theory of cable electromagnetic coupling and forecasting simulation, this paper summarized several factors that affect the electromagnetic coupling, such as distension between wires, height from the reference ground and impedance matching, and several related suggestions were given to reduce electromagnetic interference between cables or wires. In order to meet the airworthiness standards of EWIS composed in subpart H, FAR part 25, those suggestions can be as a reference of the design of aircraft EWIS wiring to improve the electromagnetic compatibility of aircraft electronic systems.

Transient thermal characteristics of airborne electronic equipment with discrete hot bands in square cavities

This study is concerned with the thermal regulation of electronic circuits confined in a closed cubical air-filled cavity. The hot active wall, which represents the electronic equipment, is composed of three parallel discrete heat source bands subjected to a constant heat flux, separated by two adiabatic bands. The second active wall is an isothermal cold plate and is facing the hot wall. The cavity channel is considered adiabatic. Transient heat exchanges through 2D natural convection are analysed for several configurations obtained through varying the inclination angle of the active wall with respect to gravity. The numerical approach conducted with the finite volumes method allowed the derivation of the thermal and dynamic characteristics of the cavity. The thermal evolution of the sources does not show any local temperature peaks that could exceed the maximum allowable temperature set by the electronic components manufacturers. This guarantees the normal operation of the equipment. The numerical analysis is complemented by experimental measurements that validate the used model and allow the correct sizing of the airborne electronic circuits.

A Study on Failure Prediction of Airborne Electronic Equipment

The mostly working time of airborne electronic equipment is under preliminary depletion failure phase, and inspection & maintenance at intervals can’t lower the failure probability. In this paper, the law of airborne electronic equipment failure is introduced firstly. Then, methods for failure prediction are summarized and analyzed. Finally, an example for predicting the airborne radar failure using the Auto-Regressive (AR) and Support Vector Regression (SVR) model is presented. On this basis, it is possible to achieve the goal that increases the reliability in working phase and establish a more scientific maintenance system and to assure the safety of airborne electronic equipment.

Computing transient electromagnetic fields radiated from lightning

The effect of lightning on airborne electronic equipment and powerlines can be severe and a study requires the solution of electromagnetic fields radiated by the lightning flash. We model the return stroke by simple dipolelike line elements with resident charges prior to the return stroke. The resulting computations are from simple closed-form expressions and permit the modeling of branched lightning. For the first time, computations bear out the observed bipolar electric fields very near the flash.

Optimal maintenance schedules of systems subject to stochastic failure

Almost all operational and standby systems need maintenance, yet this is often overlooked in the stages of design and development. Lately, maintenance has been emphasized by several factors such as rising costs of labor and material, increased complexity of systems and increased quality requirements. The aim of this paper is to develop new algorithms and analysis techniques that can be used in a general way to handle optimization of various types of inspection and maintenance schedules of systems subject to stochastic failure. Physical problems of systems in active operation with increasing failure rate are treated. Examples of such systems are: airborne electronic equipment, radio receivers, aircraft engines, etc. The optimal maintenance schedule incorporates the effects of inspection, maintenance, delayed detection, uptime and downtime costs. The techniques of classical differential calculus and dynamic programming are applied for the development of the optimal maintenance schedule.

Maintainability Prediction Revisited: Diagnostic Behavior, System Complexity, and Repair Time

If repair time for complex svstems and equipment could be related to simple overriding equipment characteristics, then prediction of repair time could be used as an equipment design tool. However, available prediction techniques have beeii shown to be inadequate for new technology. Repair time data from several thousand repairs of various types of electronics equipment, when plotted on Weibull cumulative probability paper, showed remarkablv similar characteristics, including a large skew toward longer repair times for data taken under field conditions. It was hypothesized that the skewed tail of the distribution wvas related to the way in which the maintenance technician interacted with the equipment and the environment in the diagnostic process. A three-parameter interaction model wvas developed from which the tail of the distribution and its expected value could be calculated. Measured active repair time distributions for 11 ground-based and one airborne electronic equipment wvere then compared with a family of curses computed from the model; "best-visual-fit" estimates of the three parameters were found to fall within fairly narrow ranges. The were then substituted in the expected value formula to obtain estimates of mean time to repair for the 12 equipments. While these computed estimates were found to correspond closely (r=0.98) with the actual measured values in both field and laboratorv ensvironimlenits, the validit) of the interaction model and its underlying assumptions needs to be tested further.

At the crossroads in air-traffic control III. View from the cockpit - reactions of some pilots, automatic flight management, flight-control systems, airborne CAS, 'moving map' displays, 'three-dimensional' area navigation, and others

Control of air traffic from the ground is only half the story-the airborne electronic equipment, displays, instrumentation, and human response are necessary to complete the loop in any practicable system. A few versions of collision-avoidance systems are entirely under airborne control. Based upon experience, pilots are wary of the hazards at certain major airports; in approaching other terminals, however, they have a sense of confidence that is inspired by the existence of the latest ATC equipment and facilities that afford a high degree of safety to pilots, passengers, and aircraft.

An engineering approach to hazard rate distribution functions.

A method is presented for deriving an empirical function of component hazard rates from unit time and failure histories. The probability distribution of the mean hazard rate over a selected interval is derived, together with an excellent approximation which may be used for obtaining confidence statements or conducting simulation studies. The method has been reduced to practice, including computer programs for the analysis of data and graphical display of the results. The method is applied to an item of airborne electronic equipment and the results discussed. Nomenclature X = estimator of X E(X) = expected value of X F(X) = cumulative distribution function of X H(t) = sample hazard integral Hk = increment of H(t) N(t) = sample size at unit age t Nk = mean sample size over the A;th interval C(T) = measure of hazard rate variation h(t) = unit hazard integral hk = increment of h(t) rk = number of failures occurring at the fcth failure point r(t) = cumulative number of failures occurring in the sample t = unit age tk = unit age at /bth failure point \(t) = unit hazard rate at age t T = unit age measured from beginning of useful life

Closed loop thermal process control of airborne electronic equipment.

Closed loop thermal process control of airborne electronic equipment.