scholarly journals Design of Intelligent and Open Avionics System Onboard

Author(s):  
Changqing Wu ◽  
Xiaodong Han ◽  
Yakun Wang

The continuous development of space missions has put forward requirements for high performance, high reliability, intelligence, effective integration, miniaturization, and quick turn around productization of the electronic system of satellites. The complexity of satellites has continued to increase, and the focus of satellite competition has shifted from the launch of success shifts to communication capacity, performance indicators, degree of flexibility, and continuous service capabilities. So, the importance of onboard avionics system is becoming increasingly prominent. In the future, the advanced avionics system integrates most of the platform’s electronic equipment. The design level of the system largely determines the performance of the satellite platform. This chapter focuses on the application requirements of the new generation of intelligent avionics system for future communication satellites and adopts an “open” architecture of “centralized management, distributed measurement and drive, and software and hardware ‘modular’ design” to build a universal, standardized, and scalable intelligent avionics system.

2014 ◽  
Vol 217-218 ◽  
pp. 471-480
Author(s):  
Ivano Gattelli ◽  
Gian Luigi Chiarmetta ◽  
Marcello Boschini ◽  
Renzo Moschini ◽  
Mario Rosso ◽  
...  

This paper concerns with the optimisation of the innovative rheocasting process to produce a new generation of brake callipers, characterised by very high reliability and strength. The attained very promising properties favoured their use on a very high performance car and the presented technique can be further extended for other important challenging applications. The prototype components are produced using T6 heat treated A357 alloy. Results on the samples machined directly from the produced callipers are in detail described and analysed. Pieces exhibiting some small defects, individuated by non-destructive tests, as well as defectless pieces have been underlined to severe industrial tests, e.g. high pressure tight, as well as severe bench tests, and it has been observed that the proposed technological process assure the fulfilment of the requirements contained in standards.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 327
Author(s):  
Morwenna J. Spear ◽  
Simon F. Curling ◽  
Athanasios Dimitriou ◽  
Graham A. Ormondroyd

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.


2018 ◽  
Vol 199 ◽  
pp. 09001
Author(s):  
Renaud Franssen ◽  
Serhan Guner ◽  
Luc Courard ◽  
Boyan Mihaylov

The maintenance of large aging infrastructure across the world creates serious technical, environmental, and economic challenges. Ultra-high performance fibre-reinforced concretes (UHPFRC) are a new generation of materials with outstanding mechanical properties as well as very high durability due to their extremely low permeability. These properties open new horizons for the sustainable rehabilitation of aging concrete structures. Since UHPFRC is a young and evolving material, codes are still either lacking or incomplete, with recent design provisions proposed in France, Switzerland, Japan, and Australia. However, engineers and public agencies around the world need resources to study, model, and rehabilitate structures using UHPFRC. As an effort to contribute to the efficient use of this promising material, this paper presents a new numerical modelling approach for UHPFRC-strengthened concrete members. The approach is based on the Diverse Embedment Model within the global framework of the Disturbed Stress Field Model, a smeared rotating-crack formulation for 2D modelling of reinforced concrete structures. This study presents an adapted version of the DEM in order to capture the behaviour of UHPFRC by using a small number of input parameters. The model is validated with tension tests from the literature and is then used to model UHPFRC-strengthened elements. The paper will discuss the formulation of the model and will provide validation studies with various tests of beams, columns and walls from the literature. These studies will demonstrate the effectiveness of the proposed modelling approach.


Information ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Christoph Fischer ◽  
Dennis Krummacker ◽  
Michael Karrenbauer ◽  
Hans Dieter Schotten

The use of wireless communication systems in industrial environments is gaining international importance. The requirements, which are placed thereby on the communication systems, are manifold depending on the specific use. In the field of industrial manufacturing, however, many applications are characterized by high reliability requirements and hard real-time demands. The latter requires a time-deterministic handling of processed transmissions and therefore requires the use of Time-Sensitive Networking (TSN) solutions. In this paper, we briefly describe which functionalities characterize a wireless TSN system and which approaches have already been pursued in the literature and standardization. Subsequently, we present a concept for a toolbox that allows one to combine the required functionalities into a working solution, which can be used as a guideline for software-based implementation. Additionally, since reliability of transmissions is one of the key challenges, especially in wireless communication, to achieve a performance comparable to wired systems, we provide some further design considerations to improve.


2021 ◽  
Vol 6 (51) ◽  
pp. eaaz5796
Author(s):  
I. D. Sîrbu ◽  
G. Moretti ◽  
G. Bortolotti ◽  
M. Bolignari ◽  
S. Diré ◽  
...  

Future robotic systems will be pervasive technologies operating autonomously in unknown spaces that are shared with humans. Such complex interactions make it compulsory for them to be lightweight, soft, and efficient in a way to guarantee safety, robustness, and long-term operation. Such a set of qualities can be achieved using soft multipurpose systems that combine, integrate, and commute between conventional electromechanical and fluidic drives, as well as harvest energy during inactive actuation phases for increased energy efficiency. Here, we present an electrostatic actuator made of thin films and liquid dielectrics combined with rigid polymeric stiffening elements to form a circular electrostatic bellow muscle (EBM) unit capable of out-of-plane contraction. These units are easy to manufacture and can be arranged in arrays and stacks, which can be used as a contractile artificial muscle, as a pump for fluid-driven soft robots, or as an energy harvester. As an artificial muscle, EBMs of 20 to 40 millimeters in diameter can exert forces of up to 6 newtons, lift loads over a hundred times their own weight, and reach contractions of over 40% with strain rates over 1200% per second, with a bandwidth over 10 hertz. As a pump driver, these EBMs produce flow rates of up to 0.63 liters per minute and maximum pressure head of 6 kilopascals, whereas as generator, they reach a conversion efficiency close to 20%. The compact shape, low cost, simple assembling procedure, high reliability, and large contractions make the EBM a promising technology for high-performance robotic systems.


2014 ◽  
Vol 971-973 ◽  
pp. 143-147 ◽  
Author(s):  
Ping Dai ◽  
Shuang Xiu Li

The development of a new generation of high performance gas turbine engines requires gas turbines to be operated at very high inlet temperatures, which are much higher than the allowable metal temperatures. Consequently, this necessitates the need for advanced cooling techniques. Among the numerous cooling technologies, the film cooling technology has superior advantages and relatively favorable application prospect. The recent research progress of film cooling techniques for gas turbine blade is reviewed and basic principle of film cooling is also illustrated. Progress on rotor blade and stationary blade of film cooling are introduced. Film cooling development of leading-edge was also generalized. Effect of various factor on cooling effectiveness and effect of the shape of the injection holes on plate film cooling are discussed. In addition, with respect to progress of discharge coefficient is presented. In the last, the future development trend and future investigation direction of film cooling are prospected.


1988 ◽  
Vol 110 (4) ◽  
pp. 572-577
Author(s):  
D. J. Folenta

This paper presents a brief description and several illustrations of a new concept of marine reversing gears that utilize high-performance differentially driven epicyclic gear arrangements. This new marine power transmission has the potential to offer high reliability, simplicity, light weight, high mechanical efficiency, compactness, and technological compatibility with aircraft derivative marine gas turbine engines. Further, this new reversing gear minimizes the danger of driving the free turbine in reverse as might be the case with conventional parallel shaft reversing gear arrangements. To illustrate the weight reduction potential, a modern naval ship propulsion system utilizing an aircraft derivative gas turbine engine as the prime mover in conjunction with a conventional parallel shaft reversing gear can be compared to the subject reversing gear differential. A typical 18,642 kW (25,000 hp) marine gas turbine engine might weigh approximately 5000 kg (11,000 lb) and a conventional marine technology parallel shaft reversing gear might weigh on the order of 90,000 to 136,000 kg (200,000 to 300,000 lb). Using gear technology derived from the aircraft industry, a functionally similar differentially driven marine reversing gear might weigh approximately 13,600 kg (30,000 lb).


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