scholarly journals Results of a Feasibility Study of a Prognostic System for Electro-Hydraulic Flight Control Actuators

Author(s):  
Sylvain Autin ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Jérôme Socheleau ◽  
George Vachtsevanos

Electro-Hydraulic Servo-Actuators (EHSA) are currently the most used actuation technology for primary flight control systems of civil and military aircrafts. Although some alternatives have emerged in the last decade, such as electromechanical or electro-hydrostatic solutions, electrohydraulic systems are still considered the most effective technology in flight-critical application of new commercial aircrafts. Moreover, the vast majority of aircraft currently in service are equipped with this technology. Considering the number of actuators typically employed in a primary flight control system and the expected service life of a commercial aircraft, the development of an effective PHM system could provide significant benefits to fleet operators and aircraft maintenance. This paper presents the results of a feasibility study of such a system for electro-hydraulic actuators used in fly-by-wire primary flight control systems, considering the actuator of a wide body commercial aircraft as use case. Aim of the research is the implementation of a PHM system without the addition of dedicated sensors, solution which would allow for the application of the proposed prognostic solution on both new and existing platforms. This paper describes the methodology and the results of the feasibility study through simulation and experimental activities, which shows how the novel PHM technologies proposed for a PHM system for the EHSAs of primary flight control actuators can allow the migration from scheduled to condition-based maintenance.

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 215
Author(s):  
Antonio Carlo Bertolino ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli

Electro-hydraulic servo-actuators (EHSAs) are currently considered the state-of-the art solution for the control of the primary flight control systems of civil and military aircraft. Combining the expected service life of a commercial aircraft with the fact that electro-hydraulic technology is employed in the vast majority of currently in-service aircraft and is planned to be used on future platforms as well, the development of an effective Prognostic and Health Management (PHM) system could provide significant advantages to fleet operators and aircraft maintenance, such as the reduction of unplanned flight disruptions and increased availability of the aircraft. The occurrence of excessive internal leakage within the EHSAs is one of the most common causes of return from the field of flight control actuators, making this failure mode a priority in the definition of any dedicated PHM routine. This paper presents a case study on the design of a prognostic system for this degradation mode, in the context of a wider effort toward the definition of a prognostic framework suitable to work on in-flight data. The study is performed by means of a high-fidelity simulation model supported by experimental activities. Results of both the simulation and the experimental work are used to select a suitable feature, then implemented within the prognostic framework based on particle filtering. The algorithm is at first theoretically discussed, and then tested against several degradation patterns. Performances are evaluated through state-of-the-art metrics, showing promising results and providing the basis towards future applications on real in-flight data.


2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Sylvain Autin ◽  
Jérôme Socheleau ◽  
Andrea Dellacasa ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
...  

Electro-Hydraulic Servo-Actuators (EHSA) are by far the mostly used type of actuators in aircraft primary flight control systems. Though electrical actuation is been considered since long as a possible replacement of hydraulic actuation for aircraft systems, EHSAs are still the technology of choice in the primary flight control systems of new commercial aircrafts. Considering that 10 or more EHSAs are typically used in an aircraft flight control system, the development of an effective PHM system for this equipment could provide large benefits and be of great interest for the OEMs and for the air fleet operators. This paper presents the results of a feasibility study making up the first part of an ongoing research activity focused on the development of a PHM system for EHSAs used in fly-by-wire primary flight control systems and takes as a use case the primary flight control actuator of a wide body commercial aircraft. One of the key features of the research is the implementation of a PHM system without the addition of new sensors, taking advantage of the available signals. This offers the possibility of implementation of the PHM system on the existing platforms and not only as a proposition for new aircrafts designed with a complement of additional sensors. The enabling technologies for this PHM system borrow from the area of Bayesian estimation theory and specifically particle filtering and the information acquired from EHSA in-flight and during pre-flight check is processed by appropriate algorithms in order to obtain relevant features, detect the degradation and estimate the Remaining Useful Life (RUL). The results are evaluated through appropriate metrics in order to assess the performance and effectiveness of the implemented PHM. This paper describes the methodology of the feasibility study, which shows how the novel PHM technologies proposed for a PHM system for the EHSAs of primary flight control actuators can allow the migration from unscheduled / on-condition maintenance to condition based maintenance targeting the perceived objectives of the OEM and of the aircraft operator.


1965 ◽  
Vol 180 (1) ◽  
pp. 246-259
Author(s):  
R. Ruggles

The author discusses some of the problems of failure-survival automatic flight control systems and suggests some basic ground rules as design criteria. The advantages and disadvantages of some of the main types of system are discussed: duplex, triplex, triple component, duplicate-monitored and quadruplex systems being covered. In particular, a quadruplex actuator is described which has been designed and developed mainly for automatic flight control system applications where a very high degrees of failure-survival capability is required. A detailed failure analysis of the various systems is carried out and the importance of the electrical and hydraulic supply system configurations and failure rates is brought out.


10.2514/1.807 ◽  
2004 ◽  
Vol 41 (6) ◽  
pp. 1336-1346 ◽  
Author(s):  
Gjoko Apostolovski ◽  
Yiannis Andreopoulos

Author(s):  
Min Huang ◽  
Zhong-wei Wang ◽  
Zhen-yun Guo ◽  
Yao-bin Niu

In order to provide a method for evaluating flight control systems with the wind tunnel based virtual flight testing and provide a guide for building virtual flight testing systems, the virtual flight testing evaluation method was researched. The virtual flight testing evaluation method consisted of three parts: virtual flight testing method, virtual flight testing data processing method, and flight control system performance determination method, which were respectively designed for a pitching control system. Then, the hardware-in-the-loop simulation evaluation method was presented, and comparisons between the virtual flight testing and hardware-in-the-loop simulation evaluation method were conducted to highlight the characteristics of virtual flight testing evaluation method. Finally, virtual flight testing simulation models of a sample air vehicle were built and virtual flight testing were simulated to demonstrate the virtual flight testing evaluation method, which is helpful for the understanding of the virtual flight testing evaluation method with more sensibility. The evaluation results show that the virtual flight testing evaluation method designed can be used for flight control system evaluation.


Aerospace ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 139
Author(s):  
Nunzio Natale ◽  
Teresa Salomone ◽  
Giuliano De Stefano ◽  
Antonio Piccolo

Computational fluid dynamics is employed to predict the aerodynamic properties of the prototypical trailing-edge control surfaces for a small, regional transport, commercial aircraft. The virtual experiments are performed at operational flight conditions, by resolving the mean turbulent flow field around a realistic model of the whole aircraft. The Reynolds-averaged Navier–Stokes approach is used, where the governing equations are solved with a finite volume-based numerical method. The effectiveness of the flight control system, during a hypothetical conceptual pre-design phase, is studied by conducting simulations at different angles of deflection, and examining the variation of the aerodynamic loading coefficients. The proposed computational modeling approach is verified to have good practical potential, also compared with reference industrial data provided by the Leonardo Aircraft Company.


2013 ◽  
Vol 284-287 ◽  
pp. 1883-1887
Author(s):  
Ji Hui Pan ◽  
Xiao Lin Zhang ◽  
Sheng Bing Zhang ◽  
Hao Ma

In complex systems like flight control systems etc., reliability is as important as performance. In order to improve the reliability of flight control system (FCS), the fault- tolerant technique was adopted. Three parts of the FCS which are Flight Control Fault Tolerant Computer, Redundancy sensor and Servo-actuator have been explored. The key techniques have been solved, such as Redundant Disposition, Synchronism of the Redundant Channels, Data link and Communication of Channels, etc. The experimental results show that the system meets with the fly control system’s demand of reliability.


2009 ◽  
Vol 147-149 ◽  
pp. 231-236 ◽  
Author(s):  
Tomasz Rogalski ◽  
Andrzej Tomczyk ◽  
Grzegorz Kopecki

At the Department of Avionics and Control Systems problems of aeronautical control systems have been dealt with for years. Several different kinds of aeronautical control systems have been designed, prototyped and tested. These control systems are intended for general aviation aircraft and unmanned aircraft. During all research projects computer simulations and laboratory tests were made. However, since in some cases such tests were insufficient, in-flight tests were conducted leading to a series of reliable results. The in-flight tests were made with the use of M-20 Mewa aircraft (autopilot for a GA aircraft) and PZL-110 Koliber aircraft (control system for UAV and indirect flight control system for a GA aircraft). Nevertheless, in-flight testing is very expensive and problematic. To avoid some problems appearing during in-flight tests and their preparation, a simulator – which is normally used for professional pilot training – can be used. The Aviation Training Center of the Rzeszów University of Technology possesses the ALSIM AL-200 MCC flight simulator. We have started preparing this simulator for the research. It is possible to control the simulated aircraft with the use of an external control system. The solution proposed enables testing the aircraft control algorithms, indirect control laws (e.g. control laws modifying handling qualities), as well as testing and assessment of the students’ pilotage skills. Moreover, the solution makes it possible to conduct tests connected with aircraft control, crew management, crew cooperation and flight safety. The simulator allows us to test dangerous situations, which – because of safety reasons – is impossible during in-flight testing. This paper presents modifications to the simulator’s hardware and additional software, which enable the described research.


2001 ◽  
Vol 105 (1051) ◽  
pp. 543-549 ◽  
Author(s):  
C. Fielding

The design of an advanced flight control system (FCS) is a technically challenging task for which a range of engineering disciplines have to align their skills and efforts in order to achieve a successful system design. This paper presents an overview of some of the factors which need to be considered and is intended to serve as an introduction to this stimulating subject. Specific aspects covered are: flight dynamics and handling qualities, mechanical and fly-by-wire systems, control laws and air data systems, stores carriage, actuation systems, flight control computer implementation, flexible airframe dynamics, and ground and flight testing. The flight control system challenges and expected future developments are reviewed and a comprehensive set of references is provided for further reading.


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