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impact of architectural choices and increase confidence through early verification/validation of the model assumptions. This design methodology is well suitable for a European project (SmartFuel) that proposes a distributed control strategy for aircraft fuel systems. During the first SmartFuel phase, the verification and validation of the aforementioned avionics system was successfully carried out through prototype-based simulations. The future second project phase develops models and tools to analyze, synthesize, and preverify/prevalidate the avionics system architecture at early development stages. This paper addresses the latter project phase by focusing on the prediction of system quality characteristics and the automatic code generation for the system components. It presentsasoftwaredevelopmentframeworktodealwiththeavionicssystemspecificationsbymeansofarchitectural representationsthatfacilitatetheearlyevaluationofthesystem.Theproposedmodelingmethodologyisevaluatedin simulations and prototypes, and it is compared with the results obtained from the first project phase. The experimental outcomes from two case studies (helicopter and airplane fuel systems) are also presented.

A new distributed control system for fuel management and other avionics applications is introduced. The system consists of a network of smart components such as sensors, valves, and pumps which are connected via a controlled area network bus (CANbus). Thus, no central fuel management computer is required, wiring is simplified, and the weight decreases. The heart of each smart component is a CAN-enabled microcontroller. All smart components share a copy of the same code inside its microcontroller, for easier certification. A distribution methodology has been developed based on a set of automata and on the employment of CANbus (as the communication protocol) for global state broadcasting.

This paper describes the development of a graphic computer tool that facilitates the generation of control software for a new distributed fuel management system for aircraft. The system has been the result of a three-year European Community Research Project. The goal was to move from a centralized control architecture to a fully distributed one, where each component of the system makes a decision by itself and the control of the whole system is a shared task. The interchange of information between components is performed via fieldbuses. The graphic computer tool developed is able to perform an automatic code generation starting from a graphic description of the system provided by the user. Thus, different aircraft fuel system configurations can be considered. According to the specific aircraft under study, they can include more or less tanks and components in the system. For each case, the control code of the distributed system can be quickly modified. It can, then, be integrated in each component device to operate in the system. This paper describes the main ideas of the new distributed avionic system and the graphical tool. Some experimental results in a laboratory plant simulator are also shown.

Aircrafts usually have several fuel tanks, and there are fuel transfers among these tanks along a flight. These transfers are controlled with valves, and may follow several alternative paths, since structural fuel system redundancies are provided for evident reasons. An on board program for the management and reconfiguration of the fuel system must be developed and tested. The article introduces an aircraft fuel management system simulation, which provides a platform for the study of the fuel system logic and sequencing that the on board program must implement for normal flights and for malfunction cases. The simulation environment can be easily modified and extended, for instance to consider the use of new components. A specific example is considered: an aircraft with six tanks in the wings and a tail tank. The article presents a two-layer model, the use of the model for simulation experiments, and some illustrative examples.

Model-based approaches for control software architectures reduce risks and costs in the development process of embedded systems. They allow seeing the system-wide analysis impacts of architectural choices, and increases confidence through early verification/validation of the model assumptions. This representation technique is well suitable for a European project named “SmartFuel” which proposes a distributed control strategy for aircraft fuel systems. It is an embedded system with open architecture which allows aircraft-parts manufactures to develop their own commercial off-the-shelf (COTS) fuel components, i.e. networked mechatronic devices. Within the first SmartFuel phase, the verification and validation of the above avionics system has been successfully carried out through prototype-based simulations. The second project phase aims to develop models and tools to analyze, synthesize, and pre-verify/pre-validate by model simulation the avionics system architecture at early development stages. The results expected from the modeling (i.e. prediction of key system features and the automatic code generation for the COTS components) benefit to the development process. This paper presents a Model-Based Development Framework (MBDF) to deal with the avionics system specifications, and the creation of embedded system models. In addition, the experimental outcomes when the MBDF is applied to two case studies (helicopter and airplane fuel systems) are presented.

This papers introduces a current research on avionic distributed control systems, using smart components. The research focus on fuel management systems. The nearest experimental target is real flight testing into three years. For safety reasons the new distributed system has to react with pertinent reconfigurations when there are problems in the system, as detected by the smart components. Likewise, it is possible that the fuel plant changes, for instance when extra tanks are added, so the distributed control system has to reconfigure its functionality. The specific experimental platform for the research is an helicopter. The paper describes the control problem, the control distribution concept, the smart components, and the present research for reconfiguration.

Current development processes of complex safety-critical embedded systems basically demand integrated engineering tools, and a better way to predict software-intensive performance at early design phases by focusing on nonfunctional features such as dependability, safety, etc. A suitable approach for the integration of engineering tools is the model-based system engineering (MBSE). Within this development process framework, the case study in this research work is an avionic fuel distributed control system (AFDCS) with autonomous controllers embedded in conventional mechanical fuel components. The approach comes from a European Research Project named SmartFuel which already was successfully implemented, tested and validated at laboratory, and real-scaled prototypes. From these experimental results, this paper reviews and reanalyzes the proposed AFDCS architecture design, by focusing on the final business target that is the control software certification for the creation of interoperable commercial off-the-shelf (COTS) fuel components. The information gathered from the testing and validation impacts directly on the initial phases; requirements and design. The architecture analysis & design language (AADL) was selected as description language for modeling the AFDCS architecture. It is a standard which supports MBSE. Besides, AADL is perfectly suitable for AFDCSs since it allows deploying software models on different computer resources. This paper presents the AFDCS architecture refinement of a particular helicopter fuel system by reviewing and reanalyzing its integrated AADL model. It includes a summary of the main ADFCS architecture concepts, a description of the design analysis methodology based on AADL, the key architecture points analyzed on helicopter fuel distributed control system (HFDCS), and the results obtained.

A current methodology for modeling distributed control systems (DCSs) is the standard IEC 61499. This technology is mainly applied in modern manufacturing industrial automation but it has begun to extend to other application areas. This paper proposes, in the framework of a European Research Project, a widespread use of IEC 61499, modeling an avionic distributed fuel control system (ADFCS) with smart components. The main Project target is to change the actual centralized system architecture to a full distributed one. This new system architecture includes fieldbuses and intelligence on the system components which are automata with holonic behavior. According to these new fuel system characteristics, IEC 61499 is perfectly suitable to develop it and at a time, it is interesting to spread the development of this kind of system. The paper objective is to propose a graphic modeling representation methodology to create an ADFCS with smart components. Thus, the generalization and systematization of ADFCS developments is achieved. This paper presents the main ideas of the new distributed avionic system and the control modeling of this system with IEC 61499 function blocks (FBs). Also, a particular example of ADFCS is presented; a helicopter fuel system.

A novel graphic computer tool to generate decentralized fuel control system for avionics is introduced. As a result of a European Community Research Project, a new distributed fuel management system involving fieldbus has been proposed, implemented and tested. Some different target fuel system configurations for aircrafts can be considered and according to their mission, could have more or less tanks and components in the system. For each case, the control code of the distributed system must be quickly modified. Then it can be injected into each field device to operate in the system. This paper focuses on a graphic computer tool that makes easy the control software development together with automatic code generation. This paper describes the main ideas of the new distributed avionic system and the graphical tool. Some experimental results in a laboratory physical simulator are also shown.

After some years of development, a new fuel management distributed system has been proposed by a European Research Project. The system is based on new smart components connected via a fieldbus. All components have the same microcontroller with the same control code. The smart components are valves, pumps, and sensors. A laboratory physical simulator has been implemented, to support the development of the control code. The simulator includes scaled tanks and pipes, and smart components. Fuel management functions can be reproduced, and the fieldbus behavior can be monitored. In parallel, a computer simulation has been developed, using two interconnected computers. One of the computers simulates the physical plant: fuel, tanks, valves, pumps, etc. The other computer simulates in realtime the microcontroller network. Both computers are connected via analog signals, the same signals as in the laboratory physical simulator. Now computers and physical simulator can be mixed, by switching the origin of signals, form computer or from physical plant. In this way, malfunctions and problems can be studied with non destructive tests. The paper describes the research context, and focus on the development and functionality of the hardware in the loop simulation.

A new distributed control system for fuel management and other avionics applications is introduced. The system consists in a network of smart components such as sensors, valves and pumps. They are connected via CANbus. No central fuel management computer is required. Wiring is simplified and has less weight. The heart of each smart component is a CAN-enabled microcontroller. All smart components have the same code in their microcontroller, for easier certification. BIT is implemented in each smart component. A protocol is defined for the action sequences and for message exchanging among components. This paper presents first results of an European project joining the efforts of six industry partners and three universities.

In this paper a new avionic system based on the CANbus is introduced. Fieldbuses offer less weight, standardised technology and simpler system architecture. This appears in contrast with conventional avionic systems. The paper describes main approaches and results of a European research project. The research proposes a completely distributed control, using smart components connected with a CANbus. The research focuses on the fuel management system of helicopters and aeroplanes. The paper describes the monitoring and control problem to be solved, the distributed control architecture and software, the smart components, and development steps till verification on experimental rigs.