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Article
Publication date: 19 June 2018

Chingiz Hajiyev and Ahmet Sofyali

The purpose of this paper is to present a two-stage approach for estimation of spacecraft’s position and velocity by indirect linear measurements from a single antenna.

Abstract

Purpose

The purpose of this paper is to present a two-stage approach for estimation of spacecraft’s position and velocity by indirect linear measurements from a single antenna.

Design/methodology/approach

In the first stage, direct nonlinear antenna measurements are transformed to linear x-y-z coordinate measurements of spacecraft’s position, and statistical characteristics of orbit determination errors are analyzed. Variances of orbit parameters’ errors are chosen as the accuracy criteria. In the second stage, the outputs of the first stage are improved by the designed Extended Kalman Filter for estimation of the spacecraft’s position and velocity on indirect linear x-y-z measurements.

Findings

The complex content of the measurement matrix in the conventional method causes periodic singularities in simulation results. In addition, the convergence of the filter using direct measurements is highly dependent on the initialization parameters’ values due to the nonlinear partial derivatives in the Jacobian measurement matrix. The comparison of the accuracy of both methods shows that the estimation by using indirect measurements reduces the absolute estimation errors. The simulation results show that the proposed two-stage procedure performs both with better estimation accuracy and better convergence characteristics. The method based on indirect measurements provides an unnoticeably short transient duration.

Practical implications

The proposed method can be recommended for satellite orbit estimation regarding its presented superiorities.

Originality/value

Inputting the single antenna measurements to the filter indirectly results in a quite simpler measurement matrix. As a result, the convergence of the filter is faster and estimation errors are lower.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Content available
Article
Publication date: 23 March 2010

Chingiz Hajiyev

563

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 82 no. 2
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 April 2005

Chingiz Hajiyev and Fikret Caliskan

The purpose of the paper is to present an approach to detect and isolate the aircraft sensor and control surface/actuator failures affecting the mean of the Kalman filter…

1722

Abstract

Purpose

The purpose of the paper is to present an approach to detect and isolate the aircraft sensor and control surface/actuator failures affecting the mean of the Kalman filter innovation sequence.

Design/methodology/approach

The extended Kalman filter (EKF) is developed for nonlinear flight dynamic estimation of an F‐16 fighter and the effects of the sensor and control surface/actuator failures in the innovation sequence of the designed EKF are investigated. A robust Kalman filter (RKF) is very useful to isolate the control surface/actuator failures and sensor failures. The technique for control surface detection and identification is applied to an unstable multi‐input multi‐output model of a nonlinear AFTI/F‐16 fighter. The fighter is stabilized by means of a linear quadratic optimal controller. The control gain brings all the eigenvalues that are outside the unit circle, inside the unit circle. It also keeps the mechanical limits on the deflections of control surfaces. The fighter has nine state variables and six control inputs.

Findings

In the simulations, the longitudinal and lateral dynamics of an F‐16 aircraft dynamic model are considered, and the sensor and control surface/actuator failures are detected and isolated.

Research limitations/implications

A real‐time detection of sensor and control surface/actuator failures affecting the mean of the innovation process applied to the linearized F‐16 fighter flight dynamic is examined and an effective approach to isolate the sensor and control surface/actuator failures is proposed. The nonlinear F‐16 model is linearized. Failures affecting the covariance of the innovation sequence is not considered in the paper.

Originality/value

An approach has been proposed to detect and isolate the aircraft sensor and control surface/actuator failures occurred in the aircraft control system. An extended Kalman filter has been developed for the nonlinear flight dynamic estimation of an F‐16 fighter. Failures in the sensors and control surfaces/actuators affect the characteristics of the innovation sequence of the EKF. The failures that affect the mean of the innovation sequence have been considered. When the EKF is used, the decision statistics changes regardless the fault is in the sensors or in the control surfaces/actuators, while a RKF is used, it is easy to distinguish the sensor and control surface/actuator faults.

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

Content available
430

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

Content available

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 76 no. 6
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 16 March 2010

Chingiz Hajiyev and Ali Okatan

The purpose of this paper is to design the fault detection algorithm for multidimensional dynamic systems using a new approach for checking the statistical characteristics…

Abstract

Purpose

The purpose of this paper is to design the fault detection algorithm for multidimensional dynamic systems using a new approach for checking the statistical characteristics of Kalman filter innovation sequence.

Design/methodology/approach

The proposed approach is based on given statistics for the mathematical expectation of the spectral norm of the normalized innovation matrix of the Kalman filter.

Findings

The longitudinal dynamics of an aircraft as an example is considered, and detection of various sensor faults affecting the mean and variance of the innovation sequence is examined.

Research limitations/implications

A real‐time detection of sensor faults affecting the mean and variance of the innovation sequence, applied to the linearized aircraft longitudinal dynamics, is examined. The non‐linear longitudinal dynamics model of an aircraft is linearized. Faults affecting the covariances of the innovation sequence are not considered in the paper.

Originality/value

The proposed approach permits simultaneous real‐time checking of the expected value and the variance of the innovation sequence and does not need a priori information about statistical characteristics of this sequence in the failure case.

Details

Kybernetes, vol. 39 no. 1
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 1 February 2004

Chingiz Hajiyev and Remzi Saltoglu

In this study, the integrated navigation system, consisting of radio and inertial navigation system (INS) altimeters, is presented. INS and the radio altimeter have…

Abstract

In this study, the integrated navigation system, consisting of radio and inertial navigation system (INS) altimeters, is presented. INS and the radio altimeter have different benefits and drawbacks. The integration is achieved by using an indirect Kalman filter. Hereby, the error models of the navigators are used by the Kalman filter to estimate vertical channel parameters of the navigation system. In the open loop system, INS is the main source of information, and radio altimeter provides discrete aiding data to support the estimations. At the next step of the study, in case of abrupt faults, the performance of the integrated system is examined. The optimal Kalman filter reacts with abnormal estimates to this situation as expected. To recover such a possible malfunctioning, the robust Kalman filter algorithm is suggested.

Details

Aircraft Engineering and Aerospace Technology, vol. 76 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 April 2004

Sait N. Yurt, İbrahim Ozkol and Chingiz Hajiyev

A flight simulator must be designed to generate the correct acceleration cues, attitudes and vibrations to the flight compartment to provide an extra degree of realism for…

1012

Abstract

A flight simulator must be designed to generate the correct acceleration cues, attitudes and vibrations to the flight compartment to provide an extra degree of realism for the pilots. Therefore, such a system, which has six degrees of freedom (dof), should enable to produce pitch, roll, yaw, heave, forward and lateral movement simultaneously. However, such a complex dynamic system can be modeled as a Stewart platform with pneumatic actuators, having six dof. During the simulations, on the position and orientation of moving platform, motion determination parameters and their absolute, relative errors and standard deviations are outlined. Simulation results, which are obtained, when closely examined reveal that the developed motion determination algorithm for the considered parallel dynamic mechanism is highly accurate. Additionally, a technique is introduced for the motion determination and its deviation from the given task.

Details

Aircraft Engineering and Aerospace Technology, vol. 76 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 February 2005

Rahmi Aykan, Chingiz Hajiyev and Fikret Çalişkan

The purpose of this paper is to maintain safe flight and to improve existing deicing (in‐flight removal of ice) and anti‐icing (prevention of ice accretion) systems under…

1291

Abstract

Purpose

The purpose of this paper is to maintain safe flight and to improve existing deicing (in‐flight removal of ice) and anti‐icing (prevention of ice accretion) systems under in‐flight icing conditions.Design/methodology/approach – A recent academic research on aircraft icing phenomenon is presented. Several wind tunnel tests of an experimental aircraft provided by NASA are used in the neural network training. Five ice‐affected parameters are chosen in the light of these experiments and researches. An offline artificial neural network is used as an identification technique. The Kalman filter is used to increase the state measurement's accuracy such that neural network training performance gets better. A linear A340 dynamic model is selected in cruise conditions. This linear model is simulated in time varying manner in terms of changing icing parameters in a system dynamic matrix. The obtained data are used in neural network training and testing.Findings – Airframe icing can grow in many ways and many points on aircraft. In this research, wing leading edge ice occurrence is only considered at the same level in both left and right wings. During ice growth other faults or anomalies are ignored.Originality/value – Existing icing sensors can only provide an indication about possible ice presence. They cannot give information of the exact level of ice. However, the efficiency of current control system of changed model decreases. The proposed technique offers a method to find out the model changes under icing conditions.

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

Content available
Article
Publication date: 24 May 2013

92

Abstract

Details

Kybernetes, vol. 42 no. 5
Type: Research Article
ISSN: 0368-492X

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