Fault tolerant control for partial loss of control authority in aircraft using piecewise affine slab models

In this paper, a new fault tolerant control methodology is proposed for partial loss of control authority in aircraft using piecewise affine (PWA) slab models while minimizing an upper bound on a quadratic cost function. The proposed controller stabilizes and satisfies performance bounds for both the nominal and faulty systems. The controller design criteria are cast as a set of Linear Matrix Inequalities (LMIs) that can be solved efficiently. The new technique is illustrated in a numerical example for the Beechcraft 99 aircraft model

Fault tolerant control for bimodal piecewise affine systems

This thesis addresses the design of fault-tolerant controllers and a fault identification technique for bimodal piecewise affine systems. A new fault-tolerant control methodology is presented. Fault-tolerant, state feedback controllers are synthesized for piecewise-affine (PWA) systems while minimizing an upper bound on the expected value of a quadratic cost function. The controllers are designed to deal with partial loss of control authority in the closed loop PWA system. The proposed controller design technique stabilizes and satisfies performance bounds for both the nominal and faulty systems. Another contribution is the development of a fault identification technique for bimodal piecewise affine (PWA) systems. A Luenberger-based observer structure is applied to estimate partial loss of control authority in PWA systems. More specifically, the unknown value of the fault parameter is estimated by an observer equation obtained from a Lyapunov function. The design procedure is formulated as a set of linear matrix inequalities (LMIs) and guarantees asymptotic stability of the estimation error, provided the norm of the input is upper and lower bounded by positive constants. The new PWA identification method is illustrated in a numerical example. Asa third contribution, an active fault-tolerant controller structure is proposed for bimodal PWA systems. The new active fault-tolerant controller structure is illustrated in a numerical example

Development and Evaluation of an Integral Sliding Mode Fault Tolerant Control Scheme on the RECONFIGURE Benchmark

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.This paper describes the development, application and evaluation of a linear parameter-varying integral sliding mode control allocation scheme to the RECONFIGURE benchmark model to deal with an actuator failure/fault scenario. The proposed scheme has the capability to maintain close to nominal (fault free) load factor control performance in the face of elevator failures/faults, by including a retro-fitted integral sliding mode term and then re-routing (via control allocation) the augmented control signal to healthy elevators without reconfiguring the baseline controller. In order to mitigate any chattering appearing in the elevator demands, the retro-fitted signal is based on a super-twisting sliding mode structure. This produces a control signal which is continuous and does not have the discontinuous switching nature of traditional sliding mode schemes. The scheme is evaluated using an industrial Functional Engineering Simulator developed as part of the RECONFIGURE project. Monte-Carlo campaign results are shown to demonstrate the performance of the proposed scheme.The work in this paper is supported by EU-FP7 Grant (FP7-AAT-2012-314544): RECONFIGUR

Immunity-Based Accommodation of Aircraft Subsystem Failures

This thesis presents the design, development, and flight-simulation testing of an artificial immune system (AIS) based approach for accommodation of different aircraft subsystem failures.;Failure accommodation is considered as part of a complex integrated AIS scheme that contains four major components: failure detection, identification, evaluation, and accommodation. The accommodation part consists of providing compensatory commands to the aircraft under specific abnormal conditions based on previous experience. In this research effort, the possibility of building an AIS allowing the extraction of pilot commands is investigated.;The proposed approach is based on structuring the self (nominal conditions) and the non-self (abnormal conditions) within the AIS paradigm, as sets of artificial memory cells (mimicking behavior of T-cells, B-cells, and antibodies) consisting of measurement strings, over pre-defined time windows. Each string is a set of features values at each sample time of the flight including pilot inputs, system states, and other variables. The accommodation algorithm relies on identifying the memory cell that is the most similar to the in-coming measurements. Once the best match is found, control commands corresponding to this match will be extracted from the memory and used for control purposes.;The proposed methodology is illustrated through simulation of simple maneuvers at nominal flight conditions, different actuators, and sensor failure conditions. Data for development and demonstration have been collected from West Virginia University 6-degrees-of-freedom motion-based flight simulator. The aircraft model used for this research represents a supersonic fighter which includes model following adaptive control laws based on non-linear dynamic inversion and artificial neural network augmentation.;The simulation results demonstrate the possibility of extracting pilot compensatory commands from the self/non-self structure and the capability of the AIS paradigm to address the problem of accommodating actuator and sensor malfunctions as a part of a comprehensive and integrated framework along with abnormal condition detection, identification, and evaluation

Aeronautical engineering: A continuing bibliography with indexes (supplement 195)

This bibliography lists 389 reports, articles and other documents introduced into the NASA scientific and technical information system in December 1985

Aeronautical engineering: A continuing bibliography with indexes (supplement 203)

This bibliography lists 449 reports, articles and other documents introduced into the NASA scientific and technical information system in July 1986