LOES Derivation of Non-Linear Actuation System for Flight Control Synthesis Purpose

The article deals with the architecture, performance, and experimental tests of a test bench for servo-actuators used in flight controls. After the state of the art on the subject, the innovative architecture of the built bench is described, in which flight control actuator under test and load actuator are not in line but mounted perpendicularly. The model of the bench actuating systems is then presented, consisting of the servo-controlled hydraulic actuator, load cell, speed transducer, angular position transducer of the coupling and pressure transducers. For each of these components the nonlinear multi-physics mechatronic model is described, according to the adopted solutions. The adopted force control algorithm is discussed, showing the integrative compensation on the action line and proportional-derivative on the feedback, with speed feedforward. The experimental tests carried out on the bench under stalled conditions are also presented, whose results concerning time and frequency responses are compared with those obtained through the linearized and non-linear numerical model. Finally, the non-linear models of the flight control actuator under test, controlled in position, and of the loading servo-actuator of the bench are joined together, and the results of various simulations are described.

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Feedback linearization and backstepping: an equivalence in control design of strict-feedback form

IMA Journal of Mathematical Control and Information ◽

10.1093/imamci/dnz024 ◽

2019 ◽

Vol 37 (4) ◽

pp. 1049-1069 ◽

Cited By ~ 2

Author(s):

Thanh T Tran

Keyword(s):

Flight Control ◽

Feedback Linearization ◽

High Performance ◽

Control Design ◽

Backstepping Control ◽

Analytical Models ◽

Linear Feedback ◽

Specific Class ◽

Feedback Form ◽

Non Linear

Abstract This paper investigates an equivalence between feedback linearization and backstepping control. Implications from equivalence are that stability and performance properties of one method are the same for another method. Thus, a property known to exist only for one method could be used to prove property also holds for another. Also, a suspected advantage of one method over the other could be proven to be a false conjecture. Control laws in both approaches are achieved by coordinate transformations and non-linear feedbacks. Further, resulting non-linear feedback control law achieved by feedback linearization method matches exactly with non-linear controller achieved by the backstepping control design. This equivalence is a general analytical match within the specific class of non-linear dynamic systems under investigation. Demonstrations are considered and validated via flight control of longitudinal dynamics of a high performance aircraft simulation model. Algorithms are tested and evaluated with analytical models and non-linear closed-loop simulation.

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Fly-By-Wire Dual-Dual Flight Control Actuation System

10.4271/981252 ◽

1998 ◽

Author(s):

Carlton Y. Ma

Keyword(s):

Flight Control ◽

Actuation System

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A new active asymmetry monitoring and control technique applied to critical aircraft flap control system failures

MATEC Web of Conferences ◽

10.1051/matecconf/201930404011 ◽

2019 ◽

Vol 304 ◽

pp. 04011

Author(s):

Dario Belmonte ◽

Matteo Davide Lorenzo Dalla Vedova ◽

Gaetano Quattrocchi

Keyword(s):

Control System ◽

Flight Control ◽

Angular Position ◽

Control Technique ◽

Monitoring And Control ◽

Active Monitoring ◽

Actuation System ◽

Left And Right ◽

And Control ◽

Current Monitoring

Asymmetry limitation requirements between left and right wing flap surfaces play an important role in the design of the implementation of the secondary flight control system of modern airplanes. In fact, especially in the case of sudden breaking of one of the torsion bars of the flap transmission line, the huge asymmetries that can rapidly develop could compromise the lateral-directional controllability of the whole aircraft (up to cause catastrophic occurrences). Therefore, in order to guarantee the aircraft safety (especially during take-off and landing flight phase in which the effects of asymmetries could generate uncontrollable aircraft attitudes), it is mandatory to timely detect and neutralize these asymmetries. The current monitoring techniques generally evaluate the differential angular position between left and right surfaces and, in most the events, limit the Flaps Control System (FCS) asymmetries, but in severe fault conditions (e.g. under very high aerodynamic loads), unacceptable asymmetries could be generated, compromising the controllability of the aircraft. To this purpose, in this paper the authors propose a new active monitoring and control technique capable of detecting the increasing angular error between the different flap surfaces and that, after stopping the whole actuation system, acts on the portion of the actuation line still connected to the PDU to minimize the FCS asymmetries.

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Structured Control Design for a Highly Flexible Flutter Demonstrator

Aerospace ◽

10.3390/aerospace6030027 ◽

2019 ◽

Vol 6 (3) ◽

pp. 27 ◽

Cited By ~ 10

Author(s):

Manuel Pusch ◽

Daniel Ossmann ◽

Tamás Luspay

Keyword(s):

Control System ◽

Flight Control ◽

Optimization Problems ◽

Linear Optimization ◽

Longitudinal Axis ◽

Flight Control System ◽

Flutter Suppression ◽

Model Based ◽

Non Linear ◽

Linear Optimization Problems

The model-based flight control system design for a highly flexible flutter demonstrator, developed in the European FLEXOP project, is presented. The flight control system includes a baseline controller to operate the aircraft fully autonomously and a flutter suppression controller to stabilize the unstable aeroelastic modes and extend the aircraft’s operational range. The baseline control system features a classical cascade flight control structure with scheduled control loops to augment the lateral and longitudinal axis of the aircraft. The flutter suppression controller uses an advanced blending technique to blend the flutter relevant sensor and actuator signals. These blends decouple the unstable modes and individually control them by scheduled single loop controllers. For the tuning of the free parameters in the defined controller structures, a model-based approach solving multi-objective, non-linear optimization problems is used. The developed control system, including baseline and flutter control algorithms, is verified in an extensive simulation campaign using a high fidelity simulator. The simulator is embedded in MATLAB and a features non-linear model of the aircraft dynamics itself and detailed sensor and actuator descriptions.

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Multi-Fault Diagnosis Approach Based on Updated Interacting Multiple Model for Aviation Hydraulic Actuator

Information ◽

10.3390/info11090410 ◽

2020 ◽

Vol 11 (9) ◽

pp. 410

Author(s):

Xiaozhe Sun ◽

Xingjian Wang ◽

Siru Lin

Keyword(s):

Fault Diagnosis ◽

Flight Control ◽

Failure Modes ◽

Physical Parameters ◽

Interacting Multiple Model ◽

Multiple Model ◽

Hydraulic Actuator ◽

Multiple Faults ◽

Actuation System ◽

Diagnosis Method

The aviation hydraulic actuator (HA) is a key component of the flight control system in an aircraft. It is necessary to consider the occurrence of multiple faults under harsh conditions during a flight. This study designs a multi-fault diagnosis method based on the updated interacting multiple model (UIMM). The correspondence between the failure modes and the key physical parameters of HA is found by analyzing the fault mode and mechanism. The key physical parameters of HA can be estimated by employing a series of extended Kalman filters (EKF) related to the different modes of HA. The models in UIMM are updated once the fault is determined. UIMM can reduce the number of fault models and avoid combinatorial explosion in the case of multiple faults. Simulation results indicate that the multi-fault diagnosis method based on UIMM is effective for multi-fault diagnosis of electro-hydraulic servo actuation system.

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