A Simulation Survey on the Effects of Progressing Faults Within the SCAS of a Flight Control Actuator for Helicopters

2021 ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli ◽  
Giuseppe Vitrani
Keyword(s):  
Flight Control ◽  
Health Management ◽  
Risk Mitigation ◽  
Selection Process ◽  
Stability Control ◽  
Features Selection ◽  
Vertical Walls ◽  
Low Altitude ◽  
Definition Of ◽  
Rotary Wing

Abstract Stability Control Augmentation Systems (SCAS) are widely adopted to enhance the flight stability of rotary-wing aircraft operating in difficult aerodynamic conditions, such as low altitude missions, stationary flight nearby vertical walls or in presence of heavy gusts. Such systems are based upon small electro-hydraulic servosystems controlled in position through a dedicated servovalve. The SCAS operates with limited authority over the main control linkage translating the pilot input in the movement of the main flight control actuator. Being critical for the operability of the helicopter, the definition of a Prognostics and Health Management (PHM) framework for the SCAS systems would provide significant advantages, such as better risk mitigation, improved availability, and a reduction in the occurrences of unpredicted failures which still represent one of the most known downsides of helicopters. This paper provides the results of a preliminary analysis on the effects of the inception and progression of several degradation types within a simulated SCAS system. Signals usually available within such devices are hence combined with measurements provided by additional sensors to check the feasibility of a PHM system with and without dedicated sensors. The resulting features selection process shows that although the dedicated measurements are required to design a complete PHM system, it appears nonetheless possible to obtain valuable information on the health status of the SCAS system without resorting to additional sensors.

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.

scholarly journals Design of a PHM system for electro-mechanical flight controls: a roadmap from preliminary analyses to iron-bird validation

2019 ◽  
Vol 304 ◽  
pp. 04018 ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Fault Diagnosis ◽  
Control Systems ◽  
Flight Control ◽  
Management System ◽  
Health Management ◽  
Prognostics And Health Management ◽  
Case Scenario ◽  
Flight Controls ◽  
Definition Of ◽  
New Algorithms

Literature on PHM is focused on research dedicated to the definition of new algorithms to achieve better failures prognosis or earlier and more accurate fault diagnosis, but lacks of examples on the design of novel PHM frameworks and the practical issues related with their implementation. This paper describes a roadmap for the design of a novel Prognostics and Health Management system while making reference to a real-case scenario applied to electro-mechanical actuators for flight control systems.

scholarly journals Preliminary study towards the definition of a PHM framework for the hydraulic system of a fly-by-wire helicopter

2020 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Flight Control ◽  
Hydraulic System ◽  
Preliminary Analysis ◽  
Failure Modes ◽  
Health Management ◽  
Management Approach ◽  
Critical System ◽  
Wide Range ◽  
The Subject ◽  
Definition Of

On-board hydraulic systems are tasked to provide a number of critical functions to ensure the in-flight operability of rotary-wings vehicles; the hydraulic plant is required to supply power to the flight control actuators and utilities, as well as condition the hydraulic fluid, under a wide range of possible in-service conditions. Being a flight-critical system, the definition of a Prognostics and Health Management framework would provide significant advantages to the users, such as better risk mitigation, improved availability and a reduction in the occurrences of unpredicted failures which still represent one of the more known downsides of helicopters. A preliminary analysis on the effects of the inception and progression of several degradation types is the first step towards assessing if such PHM system is feasible, and which failure modes are more likely to be observed. Moreover, since several key components are frequently provided by different suppliers to the airframer, this preliminary analysis would allow to better assess if an Integrated Vehicle Health Management approach, integrating signals coming from different components, could be beneficial. To pursue this study, a complete model of the hydraulic system for a fly-by-wire helicopter has been prepared. Then, an in-depth simulation campaign was pursued with the aim of studying the interactions between different failure modes, the effects that the propagating degradations have on the system performances and which signals can be used to define a robust set of features. The paper introduces the case-study under analysis, a general configuration for fly-by-wire helicopters, presenting the most prominent peculiarities of the system and the effect of such peculiarities on the definition of health monitoring schemes. The model is then used to describe the behavior of the system under nominal and degraded conditions is introduced. Between the possible failure modes, the interaction between wear in several mechanical components and the occlusion of the hydraulic lines filters was chosen as the subject of this study; motivations are provided and the degradation model described in detail. Hence, results of a wide-ranging simulation campaign are presented, where the time-domain response of the system is used to guide in the definition of a proper set of features able to characterize the selected fault cases. Selected features are presented, chosen according to significant metrics such as correlation with the simulated degradations, signal-to-noise ratio and accuracy. Two different approaches with a varying degree of integration between system signals are proposed and compared. Prognostics is then pursued through well-known particle filter algorithms. The analysis provides promising results on the capability of successfully detecting, isolating and identifying the selected fault mode; laying the foundations for further and more comprehensive studies on the subject.

ANALYSIS OF SPACECRAFT TELEMETRY INFORMATION USING THE KNOWLEDGE BASE, REPLENISHED DURING THEIR OPERATION

2021 ◽  
pp. 12-17
Author(s):  
S. V. Soloviev
Keyword(s):  
Time Series ◽  
Flight Control ◽  
Control Process ◽  
State Control ◽  
Mathematical Apparatus ◽  
Analysis Algorithm ◽  
Intelligent Analysis ◽  
Flight Controls ◽  
Basic Concepts ◽  
Definition Of

The method for intellectualizing the analysis of telemetric information from spacecraft arriving at ground-based flight controls is discusses. The features of state control during the spacecraft operation are formulated. The basic concepts, terms and basic properties of time series are presented, the definition of the physical meaning of the characteristic quantities for the spacecraft flight control process is given. The use of the mathematical apparatus for the analysis of time radars is substantiated in solving problems of telemetry support in the process of controlling the flight of spacecraft. A mathematical apparatus for analyzing time series is proposed to identify the actual trend. An approach to solving the problem of predicting the state of a spacecraft based on a comparative version is presented. Requirements for the intelligent analysis algorithm are presented and an integrated algorithm is proposed, a method based on time series.

Algorithmic support of low-altitude aircraft flight based on the hazard analysis of the flight situation

2021 ◽  
Author(s):  
V.A. Malyshev ◽  
A.S. Leontyev ◽  
S.P. Poluektov ◽  
Е.М. Volotov
Keyword(s):  
Adaptive Control ◽  
Flight Control ◽  
Control Algorithm ◽  
Hazard Analysis ◽  
Critical Value ◽  
Control Mode ◽  
Manual Control ◽  
Flight Safety ◽  
Low Altitude ◽  
Adaptive Control Algorithm

Low-altitude flight of an aircraft is an effective, but at the same time, a very complex tactical technique, during which the crew does not always have the opportunity to timely recognize the occurrence of an abnormal case, determine the way out of it and counteract an aviation accident development. Despite many advantages of the automatic mode of low-altitude flight performing, its practical implementation is associated with a number of features and disadvantages, which determined the preference for the manual mode of low-altitude flight control. These are the presence of telltale factors, limited ability of performing flights at night and in difficult weather conditions, insufficient reliability etc. The considered features determined the relevance of the of low-altitude flight safety ensuring problem in relation to the manual control mode. As a result of an experimental study of the low-altitude flight performing process in a manual control mode, it was found that when performing manually-controlled low-altitude flight, a hazard assessment of the flight situation becomes pivotal. However the crew being under such conditions is not always able to correctly assess the flight situation hazard due to a combination of objective reasons. The current state of the adaptive and on-board flight safety systems theory makes it possible to increase the safety of the manuallycontrolled low-altitude flight by using adaptive control algorithms based on the flight situation hazard assessment. To solve this problem an adaptive control algorithm is proposed that ensures the formation of a security corridor in the longitudinal control channel, where the upper limit is determined by the critical value of the aircraft detection hazard, and the lower limit is determined by the critical value of the error in maintaining a given flight altitude. For a continuous assessment of the flight situation hazard and the timely formation of control signals the complex information about the current true flight altitude and the foreground is needed. Taking into account the peculiarities of low-altitude flight a digital terrain map containing data on natural and artificial obstacles along the flight route is a more rational source of information, that will make it possible to predict the development of the flight situation hazard. The above reasoning makes it possible to form an aircraft low-altitude flight adaptive control algorithm. A distinctive feature of the proposed algorithm is the implementation of a combined control variety where the pilot is provided with ample manual control opportunities within the security corridor, and the automatic flight control system is assigned the role of a safety subsystem that ensures control and timely return of the flight situation to normal flight conditions. The presented algorithm will allow to increase the crew logical-analytical activity information support during continuous analysis of the existing flight situation due to the formation of protective control actions based on the current flight situation hazard analysis.

scholarly journals Definition of Reference Models for Power, Weight, Working Width, and Price for Seeding Machines

Agriculture ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 186 ◽  
Author(s):  
Tatevik Yezekyan ◽  
Francesco Marinello ◽  
Giannantonio Armentano ◽  
Samuele Trestini ◽  
Luigi Sartori
Keyword(s):  
Environmental Performance ◽  
Selection Process ◽  
List Price ◽  
Power Weight ◽  
Technical Parameters ◽  
Functional Parameters ◽  
Fleet Composition ◽  
Reference Equations ◽  
Definition Of ◽  
Perceived Choice

Machine functional parameters define fleet composition and management and, thus, play an important role in economic and environmental performance. Large availability of programming methods and decision support systems are available in the market, however, there is still a lack of applicative tools to forecast the perceived and necessary technical parameters and machinery price options to complete tasks. In the current research, most correlated functional parameters for four group of seeding machines were determined with the application of linear and multiple linear regression analyses. Power, weight, working width, number of rows, and list price were studied, and reference equations were developed for seed drills, precision, combined and no-tillage planters. Two statistical analyses models were, therefore, developed for each of the groups in order to allow evaluation and prediction of performance and cost, thus contributing to the selection process optimisation and perceived choice of the needed implement.

scholarly journals A simplified monitoring model for PMSM servoactuator prognostics

2019 ◽  
Vol 304 ◽  
pp. 04013 ◽  
Author(s):  
Pier Carlo Berri ◽  
Matteo D.L. Dalla Vedova ◽  
Paolo Maggiore ◽  
Francesco Viglione
Keyword(s):  
Failure Modes ◽  
Position Control ◽  
Health Management ◽  
Risk Mitigation ◽  
Fuel Efficiency ◽  
Computational Cost ◽  
Weight Ratio ◽  
Safety Critical ◽  
Aircraft Systems ◽  
Fidelity Model

Electromechanical actuators (EMAs) based on Permanent Magnet Synchronous Motors (PMSMs) are currently employed on various aircraft systems, and are becoming more and more widespread in safety critical applications. Compared to other electrical machines, PMSM offer a high power to weight ratio and low cogging: this makes them suited for position control and actuation tasks. EMAs offer several advantages over hydraulic servoactuators, in terms of modularity, mechanical simplicity, overall weight and fuel efficiency. At the same time, their basic reliability is inherently lower compared to hydraulic actuators. Then, the use of EMAs for safety critical aircraft systems requires the adoption of risk mitigation techniques to counter this issue. In this framework, diagnostic and prognostic strategies can be used for the system health management, to monitor its behaviour in search of the early signs of the most common or dangerous failure modes. We propose a low fidelity model of a PMSM based EMA, intended for model-based diagnostic and prognostic monitoring. The model features low computational cost, allowing the execution in nearly real-time, combined with suitable accuracy in the simulation of faulty system operations. This simplified emulator is validated by comparing its behaviour to a higher fidelity model, employed as a simulated test bench.

Sign in / Sign up

Export Citation Format

Share Document