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Scholten, Pepijn A. (author), van Paassen, M.M. (author), Chu, Q. P. (author), Mulder, Max (author)
A variable stability in-flight simulator has the capabilities to change the response of an aircraft in-flight, often without changing the physical properties of the aircraft. The ability to adjust the aircraft response characteristics and handling qualities has various purposes, such as pilot training, control system development, and handling...
journal article 2020
document
Sun, L.G. (author), De Visser, C.C. (author), Chu, Q.P. (author), Mulder, J.A. (author)
Avoiding high computational loads is essential to online aerodynamic model identi- fication algorithms, which are at the heart of any model-based adaptive flight control system. Multivariate simplex B-spline (MVSB) methods are excellent function approximation tools for modeling the nonlinear aerodynamics of high performance aircraft. However,...
journal article 2013
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Sun, L.G. (author), De Visser, C.C. (author), Chu, Q.P. (author), Mulder, J.A. (author)
The optimality of the kernel number and kernel centers plays a significant role in determining the approximation power of nearly all kernel methods. However, the process of choosing optimal kernels is always formulated as a global optimization task, which is hard to accomplish. Recently, an algorithm, namely improved recursive reduced least...
journal article 2012
document
De Weerdt, E. (author), Van Kampen, E. (author), Chu, Q.P. (author), Mulder, J.A. (author)
Trajectory optimization has been a large field of research for many years. The drawback is that for non-convex, constrained problems practically all available solvers cannot guarantee that the globally optimal trajectory is found. Interval analysis based solvers however can provide this guarantee. Interval analysis has been applied to trajectory...
conference paper 2011
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Van Oort, E.R. (author), Sonneveldt, L. (author), Chu, Q.P. (author), Mulder, J.A. (author)
In this paper nonlinear adaptive flight control laws based on the backstepping approach are proposed which are applicable to over-actuated nonlinear systems. Instead of solving the control allocation exactly, update laws for the desired control effector signals are defined such that they converge to the optimal solution. Stability and...
conference paper 2011
document
De Visser, C.C. (author), Chu, Q.P. (author), Mulder, J.A. (author)
The ability to perform online model identification for nonlinear systems with unknown dynamics is essential to any adaptive model-based control system. In this paper, a new differential equality constrained recursive least squares estimator for multivariate simplex splines is presented that is able to perform online model identification and...
journal article 2011
document
Sieberling, S. (author), Chu, Q.P. (author), Mulder, J.A. (author)
This paper presents a flight control strategy based on nonlinear dynamic inversion. The approach presented, called incremental nonlinear dynamic inversion, uses properties of general mechanical systems and nonlinear dynamic inversion by feeding back angular accelerations. Theoretically, feedback of angular accelerations eliminates sensitivity to...
journal article 2010
document
Lombaerts, T.J.J. (author), Looye, G.H.N. (author), Chu, Q.P. (author), Mulder, J.A. (author)
This paper describes how the previously developed concept of Pseudo Control Hedging (PCH) can be integrated in a Fault Tolerant Flight Controller (FTFC) as a safe flight envelope protection system of the first degree. This PCH algorithm adapts the reference model for the system output in case of unachievable commands due to control input...
conference paper 2010
document
Van Kampen, E. (author), Chu, Q.P. (author), Mulder, J.A. (author)
This paper applies interval optimization to the fixed-time multiple impulse rendezvous and docking problem. Current methods for solving this type of optimization problem include for example genetic algorithms and gradient based optimization. Unlike these methods, interval methods can guarantee that the globally best solution is found for a given...
conference paper 2010
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Verveld, M.J. (author), Chu, Q.P. (author), De Wagter, C. (author), Mulder, J.A. (author)
This work addresses the problem of indoor state estimation for autonomous flying vehicles with an optic flow approach. The paper discusses a sensor configuration using six optic flow sensors of the computer mouse type augmented by a three-axis accelerometer to estimate velocity, rotation, attitude and viewing distances. It is shown that the...
conference paper 2010
document
Lombaerts, T.J.J. (author), Smaili, M.H. (author), Stroosma, O. (author), Chu, Q.P. (author), Mulder, J.A. (author), Joosten, D.A. (author)
A high fidelity aircraft simulation model, reconstructed using the Digital Flight Data Recorder (DFDR) of the 1992 Amsterdam Bijlmermeer aircraft accident (Flight 1862), has been used to evaluate a new Fault-Tolerant Flight Control Algorithm in an online piloted evaluation. This paper focuses on the piloted simulator evaluation results....
conference paper 2010
document
Sonneveldt, L. (author), Van Oort, E.R. (author), Chu, Q.P. (author), Mulder, J.A. (author)
In this paper a theoretical framework for nonlinear adaptive flight control is developed and applied to a simplified, over-actuated nonlinear fighter aircraft model. The framework is based on a modular adaptive backstepping scheme with a new type of nonlinear estimator. The nonlinear estimator is constructed using an invariant manifold based...
conference paper 2010
document
Van Oort, E.R. (author), Sonneveldt, L. (author), Chu, Q.P. (author), Mulder, J.A. (author)
A new adaptive nonlinear flight controller is designed for a high fidelity, six degrees of freedom F-16 model for the entire flight envelope. The design is based on a modular approach which separates the design of the control law and the online identifier. The control law design is based on backstepping with nonlinear damping terms to robustify...
conference paper 2010
document
De Visser, C.C. (author), Chu, Q.P. (author), Mulder, J.A. (author)
A new methodology for creating highly accurate, static nonlinear maps from scattered, multivariate data is presented. This new methodology uses the B-form polynomials of multivariate simplex splines in a new linear regression scheme. This allows the use of standard parameter estimation techniques for estimating the B-coefficients of the...
journal article 2009
document
Zaal, P.M.T. (author), Pool, D.M. (author), Chu, Q.P. (author), Van Paassen, M.M. (author), Mulder, M. (author), Mulder, J.A. (author)
This paper presents a new method for estimating the parameters of multi-channel pilot models that is based on maximum likelihood estimation. To cope with the inherent nonlinearity of this optimization problem, the gradient-based Gauss-Newton algorithm commonly used to optimize the likelihood function in terms of output error is complemented with...
journal article 2009
document
De Weerdt, E. (author), Chu, Q.P. (author), Mulder, J.A. (author)
The problem of output optimization within a specified input space of neural networks (NNs) with fixed weights is discussed in this paper. The problem is (highly) nonlinear when nonlinear activation functions are used. This global optimization problem is encountered in the reinforcement learning (RL) community. Interval analysis is applied to...
journal article 2009
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