The detection of pilot‐induced oscillations

Fly‐by‐wire systems enable superior control of chosen flight parameters. A pilot can modify stabilized parameters by adequate movement of control inceptors such as a side‐stick or trust lever. Fly‐by‐wire control reduces the load on a pilot and allows a pilot to focus on the main tasks. Unfortunately, the use of more complicated interfaces between human and machine can cause incorrect pilot behavior and in many cases lead to erroneous interactions between the operator and effective aircraft dynamics. The structure of control laws and dynamics of electromechanical actuators are especially important factors. They can influence unfavorable aircraft‐pilot coupling and can lead to pilot‐induced oscillations (PIO) in certain cases. The automatic detection of PIOs is presented in this paper. The practical realization of a PIO‐detector and examples of diagnostics of human‐machine systems are reported on in this article. First published online: 14 Oct 201

Detection of aircraft touchdown using longitudinal acceleration and continuous wavelet transformation

The paper presents a methodology enabling the detection of aircraft touchdowns based on data obtained from accelerometers attached to the structural parts of the airframe in the cockpit or passenger compartment. Precise determination of the moment and place of touchdown of the main landing gear is challenging when analysing parameters such as height, flight speed and rate of descent. During the tests of the I-31T aircraft, it turned out that vibrations of the aircraft structure caused by the contact of the front and main landing gear with the ground have a repetitive character. In particular, this applies to longitudinal acceleration. The use of continuous wavelet analysis (CWT) allowed finding unique periodic features of the landing phenomenon that distinguish it from other forms of vibration occurring in individual flight phases. Ground and flight observations of experimental aeroplane MP-02 Czajka verified the proposed method of virtual touchdown detection. The results presented in this paper justify that this method may find broader application, especially for the light aircraft class

Controllers for fault tolerant actuators

The Fly‐by‐Wire technology enables flexible shaping of both effective dynamics and handling qualities of aircraft. This solution extends aircraft possibilities and supports the pilot by use of high‐level control laws. Application of FBW for aircraft would make flying both safer, and more popular. On the other hand the FBW system must be highly reliable. Advanced indirect flight control technology requires the use of actuators characterized by fault tolerant architecture. It should enable improvement of reliability of the aircraft control system and safety of performed flights effectively. The Electromechanical Actuator (EMA) consists of the electric motor, gearbox and controller. The actuator controller should be made intrinsically reliable and should be insensitive to other equipment failure. The conception of fault tolerant control algorithms as well as practical realization of it has been presented in this work. Tests of reliability of the complete EMA unit have also been presented herein. First published online: 14 Oct 201

Right ventricle to pulmonary artery coupling as a predictor of perioperative outcome in patients with secondary mitral valve insufficiency

Background: The aim of the study was to assess some parameters of right ventricle (RV) function aspredictors of short-term mortality in patients with severe secondary mitral regurgitation (SMR) aftermitral valve surgery.Methods: We conducted a retrospective analysis of 112 consecutive patients with severe SMR whohad undergone mitral valve repair or replacement with or without concomitant coronary artery bypasssurgery. We assessed RV to pulmonary artery coupling by calculating the ratio of tricuspid annularplane systolic excursion (TAPSE) to non-invasively estimated RV systolic pressure (RVSP). The studyendpoint was 30 days post-procedural mortality.Results: Overall, the 30-day mortality was 6%. TAPSE/RVSP ratio < 0.42 mm/mmHg was a significantpredictor of mortality and remained so after adjusting for age and sex. The Kaplan-Meier survivalanalysis showed that patients with RVSP > 55 mmHg and those with TAPSE/RVSP ratio < 0.42 mm/mmHg had a lower survival probability.Conclusions: TAPSE/RVSP < 0.42 mm/mmHg is a strong predictor of short-term mortality in patientswith SMR when considered for valve surgery

Monitoring and data acquisition system for experimental general aviation fly‐by‐wire aircraft

A CAN data bus was used in a project of an experimental Fly‐by‐Wire control system (SPS‐1) mounted on board a PZL‐110 “Koliber” general aviation aircraft. This solution allows the free communication between flight control computers and individual modules of the system. The monitoring of the bus state and data frames is useful during particular hardware tests, system integration, laboratory and in‐flight tests. This report intends to present the specific monitor tool developed with the to SPS‐1. The main part of the CAN monitoring system is software. It realizes acquisition, visualization and conversion of stored data. The monitoring software operates with devices used by an experimental control system and connected to the bus. Particular devices are assigned to separate windows. The operator can control the SPS‐1 system through specialized windows or by virtual cockpit. Apart from this, the CAN monitor controls and simulates selected modules of the SPS‐1 system and works as the bus diagnostics tool. First Published Online: 14 Oct 201

Estimation of Atmospheric Gusts Using Integrated On-Board Systems of a Jet Transport Airplane—Flight Simulations

Currently, quite accurate measurements of atmospheric gusts are carried out by airport systems only in the vicinity of the runways. There is a still open issue of availability of information about real wind gusts at cruising altitudes and during approach at a considerable distance from the airfield. Standard on-board systems of a jet transport airplane provide some information which is desirable to have knowledge of how flight parameters reflect real gust parameters and their impact on the aircraft dynamics. The paper proposes an algorithm for headwind gust magnitude estimation in relation to aircraft response. The analysed estimation algorithms assume the use of data available from the existing on-board systems only without the employment of any extra sensors or ground and satellite systems. In this way, many problems caused by different structures, configurations, and ways of installation of additional sensors and structural changes are rejected. The algorithms use the classical method for estimation of wind parameters as well as a linear longitudinal model of aircraft dynamics, taking into account the influence of wind gusts. Data fusion was realised with the use of three filtration methods. Results were evaluated to select the most accurate method of the estimation. Test data were obtained from advanced flight simulation. The experimental scenario considered a flight of a passenger twin-engine jet airplane through a layer of programmed gusts. The results of the flight simulations allowed us to determine the accuracy of the proposed gust estimation algorithms in reference to the ideal wind-speed data analysis obtained directly from the simulation environment (with the accuracy of the simulation process). The use of the proposed gust estimation algorithms may provide more accurate signal for integrated on-board systems, especially for wind shear detection and sped-up response time of flight control systems, protecting aircrafts against the adverse impact of encountered wind shear or gusts, e.g., auto-thrust or auto-throttle systems. The dedicated algorithm presented in the paper may increase the safety level of take-off and approach phases in gusty conditions and also during significant changes in wind speed at cruising altitudes in the case of crossing the area of jet stream occurrence

Estimation of Atmospheric Gusts Using Integrated On-Board Systems of a Jet Transport Airplane—Flight Simulations

Currently, quite accurate measurements of atmospheric gusts are carried out by airport systems only in the vicinity of the runways. There is a still open issue of availability of information about real wind gusts at cruising altitudes and during approach at a considerable distance from the airfield. Standard on-board systems of a jet transport airplane provide some information which is desirable to have knowledge of how flight parameters reflect real gust parameters and their impact on the aircraft dynamics. The paper proposes an algorithm for headwind gust magnitude estimation in relation to aircraft response. The analysed estimation algorithms assume the use of data available from the existing on-board systems only without the employment of any extra sensors or ground and satellite systems. In this way, many problems caused by different structures, configurations, and ways of installation of additional sensors and structural changes are rejected. The algorithms use the classical method for estimation of wind parameters as well as a linear longitudinal model of aircraft dynamics, taking into account the influence of wind gusts. Data fusion was realised with the use of three filtration methods. Results were evaluated to select the most accurate method of the estimation. Test data were obtained from advanced flight simulation. The experimental scenario considered a flight of a passenger twin-engine jet airplane through a layer of programmed gusts. The results of the flight simulations allowed us to determine the accuracy of the proposed gust estimation algorithms in reference to the ideal wind-speed data analysis obtained directly from the simulation environment (with the accuracy of the simulation process). The use of the proposed gust estimation algorithms may provide more accurate signal for integrated on-board systems, especially for wind shear detection and sped-up response time of flight control systems, protecting aircrafts against the adverse impact of encountered wind shear or gusts, e.g., auto-thrust or auto-throttle systems. The dedicated algorithm presented in the paper may increase the safety level of take-off and approach phases in gusty conditions and also during significant changes in wind speed at cruising altitudes in the case of crossing the area of jet stream occurrence

Układ wizyjny wspomagający pilota w warunkach zmiennego oświetlenia

The aim of this study is to demonstrate the applicability of contemporary optoelectronic systems supported by image processing algorithms in aviation. Optoelectronic systems can support the pilot’s work or the work of an Unmanned Aerial Vehicle (UAV) operator after being installed in the cockpit of the pilot or in a ground station. The origin of the problem is related to the aspects of safe operation of the aircraft in the conditions of dynamically changing ambient light observed by the aircraft pilot or operator monitoring the monitor at the ground station and observing the image from the camera installed on the UAV. The proposed solution is to help avoid situations in which the pilot’s/operator’s situational awareness deteriorates due to strong optical phenomena.Celem niniejszego opracowania jest zademonstrowanie możliwości zastosowania współczesnych układów optoelektronicznych wspomaganych przez algorytmy przetwarzania obrazu w lotnictwie. Układy optoelektroniczne mogą wspomóc pracę pilota lub pracę operatora bezzałogowego statku powietrznego (BSP) po zainstalowaniu w kabinie pilota bądź w stacji naziemnej. Geneza problemu jest związania z aspektami bezpiecznej eksploatacji statku powietrznego w warunkach dynamicznie zmieniającego się oświetlenia otoczenia obserwowanego przez pilota samolotu lub operatora śledzącego monitor w stacji naziemnej i obserwującego obraz z kamery zainstalowanej na BSP. Zaproponowane rozwiązanie ma pomóc uniknąć sytuacji, w których świadomość sytuacyjna pilota/operatora pogarsza się na skutek silnych zjawisk optycznych