scholarly journals CONTROLLERS FOR FAULT TOLERANT ACTUATORS

Aviation ◽  
2007 ◽  
Vol 11 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Bogusław Dołega ◽  
Paweł Rzucidło

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.

2009 ◽  
Vol 147-149 ◽  
pp. 231-236 ◽  
Author(s):  
Tomasz Rogalski ◽  
Andrzej Tomczyk ◽  
Grzegorz Kopecki

At the Department of Avionics and Control Systems problems of aeronautical control systems have been dealt with for years. Several different kinds of aeronautical control systems have been designed, prototyped and tested. These control systems are intended for general aviation aircraft and unmanned aircraft. During all research projects computer simulations and laboratory tests were made. However, since in some cases such tests were insufficient, in-flight tests were conducted leading to a series of reliable results. The in-flight tests were made with the use of M-20 Mewa aircraft (autopilot for a GA aircraft) and PZL-110 Koliber aircraft (control system for UAV and indirect flight control system for a GA aircraft). Nevertheless, in-flight testing is very expensive and problematic. To avoid some problems appearing during in-flight tests and their preparation, a simulator – which is normally used for professional pilot training – can be used. The Aviation Training Center of the Rzeszów University of Technology possesses the ALSIM AL-200 MCC flight simulator. We have started preparing this simulator for the research. It is possible to control the simulated aircraft with the use of an external control system. The solution proposed enables testing the aircraft control algorithms, indirect control laws (e.g. control laws modifying handling qualities), as well as testing and assessment of the students’ pilotage skills. Moreover, the solution makes it possible to conduct tests connected with aircraft control, crew management, crew cooperation and flight safety. The simulator allows us to test dangerous situations, which – because of safety reasons – is impossible during in-flight testing. This paper presents modifications to the simulator’s hardware and additional software, which enable the described research.


Author(s):  
Muhammad Tayyeb ◽  
Umar Riaz ◽  
Arslan Ahmed Amin ◽  
Omer Saleem ◽  
Muhammad Arslan ◽  
...  

Elevators are surfaces of flight control, typically at the rear of an aircraft to control the pitch of the plane, the angle of attack and the wing lift. The most critical actuation device is longitudinal aircraft control, and its failures will result in a catastrophic aircraft crash. This paper proposes a Highly Redundant Fault Tolerant Control (HRFTC) policy for the aircraft to accommodate faults in the critical sensors and actuators. Modified Triple Modular Redundancy (MTMR) has been proposed for the sensors and Dual Redundancy (DR) has been proposed for the actuators.  The working of control laws, pilot order, signal conditioning, and failure are elaborated. Furthermore, the PID controller is used for the adjustment of the position of the elevator by comparing it with a set point. The results show that when a fault occurs, the system detects it successfully and tolerates it quickly without disturbing the flight of aircraft. The study is significant for the avionics industry for manufacturing highly reliable machines for human and environmental safety.


Author(s):  
Ali Bouchaib ◽  
Rachid Taleb ◽  
Ahmed Massoum ◽  
Saad Mekhilef

The traditional quadcopter control systems should deal with two common problems. Namely, the singularities related to the inverse kinematics and the ambiguity linked to the quaternion representation of the dynamic model. Moreover, the stability problem due to the system nonlinearity and high degree of coupling. This paper provides a solution to the two issues by employing a geometrical integral-backstepping control system. The integral terms were added to improve system ability to track desired trajectories. The high-level control laws are considered as a virtual control and transmitted to the low-level to track the high-level commands. The proposed control system along with the quadcopter dynamic model were expressed in the special Euclidean group SE(3). Finally, the control system robustness against mismatching parameters was studied while tracking various paths.


2011 ◽  
Vol 115 (1165) ◽  
pp. 163-174 ◽  
Author(s):  
D. Saussié ◽  
C. Bérard ◽  
O. Akhrif ◽  
L. Saydy

AbstractClassic flight control systems are still widely used in the industry because of acquired experience and good understanding of their structure. Nevertheless, with more stringent constraints, it becomes difficult to easily fulfil all the criteria with these classic control laws. On the other hand, modern methods can handle many constraints but fail to produce low order controllers. The following methodology proposed in this paper addresses both classic and modern flight control issues, to offer a solution that leverages the strengths of both approaches. First, anH∞synthesis is performed in order to get controllers which satisfy handling qualities and are robust with respect to mass and centre of gravity variations. These controllers are then reduced and structured by using robust modal control techniques. In conclusion, a self-scheduling technique is described that will schedule these controllers over the entire flight envelope.


2001 ◽  
Vol 105 (1051) ◽  
pp. 543-549 ◽  
Author(s):  
C. Fielding

The design of an advanced flight control system (FCS) is a technically challenging task for which a range of engineering disciplines have to align their skills and efforts in order to achieve a successful system design. This paper presents an overview of some of the factors which need to be considered and is intended to serve as an introduction to this stimulating subject. Specific aspects covered are: flight dynamics and handling qualities, mechanical and fly-by-wire systems, control laws and air data systems, stores carriage, actuation systems, flight control computer implementation, flexible airframe dynamics, and ground and flight testing. The flight control system challenges and expected future developments are reviewed and a comprehensive set of references is provided for further reading.


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