scholarly journals Feasibility Study of a PHM System for Electro-hydraulic Servo-actuators for Primary Flight Controls

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Sylvain Autin ◽  
Jérôme Socheleau ◽  
Andrea Dellacasa ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
...  
Keyword(s):  
Control Systems ◽  
Feasibility Study ◽  
Flight Control ◽  
Particle Filtering ◽  
Remaining Useful Life ◽  
Research Activity ◽  
Ongoing Research ◽  
Flight Controls ◽  
Aircraft Flight Control ◽  
Hydraulic Servo

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.

Manœuvre Demand Control for Aircraft

1970 ◽  
Vol 23 (4) ◽  
pp. 492-504
Author(s):  
G. T. Shanks
Keyword(s):  
Control Systems ◽  
Flight Control ◽  
Control Techniques ◽  
Aircraft Flight ◽  
Flight Controls ◽  
Aircraft Flight Control ◽  
Manual Handling ◽  
Work Done ◽  
Demand Control ◽  
Automatic Pilot

The coverage of this paper, which was presented at an Ordinary Meeting of the Institute held in London on 18 March 1970, includes:(1) A brief review of current aircraft flight control systems.(2) A discussion of the benefits to be gained in terms of manual handling and full automatic pilot modes, in using feedback control techniques in the primary flight controls (Manœuvre Demand Control).(3) A description of the work done on Manœuvre Demand Control at the Royal Aircraft Establishment, Farnborough, in the Avro 707C aircraft and in the Hunter Mk. 12 aircraft.

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

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Sylvain Autin ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Jérôme Socheleau ◽  
George Vachtsevanos
Keyword(s):  
Control Systems ◽  
Feasibility Study ◽  
Flight Control ◽  
The Novel ◽  
Flight Control System ◽  
Commercial Aircraft ◽  
Prognostic System ◽  
Effective Technology ◽  
Hydraulic Servo ◽  
Commercial Aircrafts

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.

scholarly journals A Case Study on the Detection and Prognosis of Internal Leakages in Electro-Hydraulic Flight Control Actuators

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 215
Author(s):  
Antonio Carlo Bertolino ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Flight Control ◽  
Particle Filtering ◽  
Health Management ◽  
State Of The Art ◽  
Commercial Aircraft ◽  
Flight Data ◽  
Prognostic System ◽  
Hydraulic Servo ◽  
Definition Of

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.

EHSA Primary Flight Controls Seals Wear Degradation Model

2018 ◽  
Author(s):  
Antonio C. Bertolino ◽  
Rocco Gentile ◽  
Giovanni Jacazio ◽  
Francesco Marino ◽  
Massimo Sorli
Keyword(s):  
Power Systems ◽  
Health Management ◽  
Research Activity ◽  
Degradation Model ◽  
Cross Section Area ◽  
Section Area ◽  
Starting Point ◽  
Flight Controls ◽  
Servo Actuator ◽  
Hydraulic Servo

Seals are widely used in hydraulic power systems to prevent fluid leakages. However, several types of degradation can decrease the performance of these components such as wear, which induces changes in the geometry of the cross-section area, influencing their sealing capability. Over the years, their behaviour has been primarily investigated with several theoretical and experimental researches. All these valuable results can be considered as a starting point for further investigations on the interaction between seals and the complete hydraulic equipment and on the root of seals degradation. This article proposes a physical model of performance degradation acting on dynamic seals of an electro-hydraulic servo-actuator (EHSA) ram for primary flight controls. In this article, a dynamic non-linear seals degradation model has been developed, based on the Hart-Smith hyperelasticity model, which physically describes the stress and strain of “rubber-like” materials. Similarly, wearing has been assessment by using the Archard’s equation. Furthermore, different operating temperatures have been considered to analyze the effect on seals performances. The integration between the mentioned seals degradation model and the high-fidelity model of the complete EHSA allows to evaluate the influence of various wear levels on the actuator behaviour. This research activity is inserted into a more extensive project of Prognostic and Health Management (PHM) of EHSAs. The results of the proposed simulations reveal how the performance of an EHSA can be affected by seals degradations.

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