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Stalls and Splines: Current Trends in Flight Testing and Aerodynamic Model Identification

de Visser, C.C. (author), Pool, D.M. (author)

Aerodynamic model identification remains essential for simulator operations and control system design and operations. In this paper, state-of-the-art methodologies for aerodynamic model identification and validation are presented, together with a number of novel applications of the identified models that were recently investigated and developed...

journal article 2023

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Loss-of-Control Prediction of a Quadcopter Using Recurrent Neural Networks

Altena, A. (author), van Beers, J.J. (author), de Visser, C.C. (author)

Loss of control (LOC) is a prevalent cause of drone crashes. Onboard prevention systems should be designed requiring low computing power, for which data-driven techniques provide a promising solution. This study proposes the use of recurrent neural networks (RNNs) for LOC prediction. Four architectures were trained in order to identify which RNN...

journal article 2023

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Development of a quasi-linear parameter varying model for a tiltrotor aircraft

Nabi, H.N. (author), de Visser, C.C. (author), Pavel, M.D. (author), Quaranta, Giuseppe (author)

The research presented in this paper focuses on the development of a quasi-Linear Parameter Varying (qLPV) model for the XV-15 tiltrotor aircraft. The specific category of qLPV modeling technique, known as the model stitching technique, is employed to model the time-varying dynamics of XV-15 tiltrotor aircraft over the entire flight envelope....

journal article 2021

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Adaptive real-time clustering method for dynamic visual tracking of very flexible wings

Mkhoyan, T. (author), de Visser, C.C. (author), De Breuker, R. (author)

Advancements in aircraft controller design, paired with increasingly flexible aircraft concepts, create the need for the development of novel (smart) adaptive sensing methods suitable for aeroelastic state estimation. A potentially universal and noninvasive approach is visual tracking. However, many tracking methods require manual selection...

journal article 2021

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Incremental Nonlinear Fault-Tolerant Control of a Quadrotor With Complete Loss of Two Opposing Rotors

Sun, Sihao (author), Wang, Xuerui (author), Chu, Q. P. (author), de Visser, C.C. (author)

In order to further expand the flight envelope of quadrotors under actuator failures, we design a nonlinear sensor-based fault-tolerant controller to stabilize a quadrotor with failure of two opposing rotors in the high-speed flight condition (>8 m/s). The incremental nonlinear dynamic inversion approach which excels in handling model...

journal article 2020

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Horizontal and vertical thermospheric cross-wind from GOCE linear and angular accelerations

Visser, T. (author), March, G. (author), Doornbos, E.N. (author), de Visser, C.C. (author), Visser, P (author)

Thermospheric wind measurements obtained from linear non-gravitational accelerations of the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite show discrepancies when compared to ground-based measurements. In this paper the cross-wind is derived from both the linear and the angular accelerations using a newly developed...

journal article 2019

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Modelling wing wake and tail aerodynamics of a flapping-wing micro aerial vehicle

Armanini, S.F. (author), Caetano, J. V. (author), de Visser, C.C. (author), Pavel, M.D. (author), de Croon, G.C.H.E. (author), Mulder, Max (author)

Despite significant interest in tailless flapping-wing micro aerial vehicle designs, tailed configurations are often favoured, as they offer many benefits, such as static stability and a simpler control strategy, separating wing and tail control. However, the tail aerodynamics are highly complex due to the interaction between the unsteady...

journal article 2019

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In-flight model parameter and state estimation using gradient descent for high-speed flight

Li, S. (author), de Wagter, C. (author), de Visser, C.C. (author), Chu, Q. P. (author), de Croon, G.C.H.E. (author)

High-speed flight in GPS-denied environments is currently an important frontier in the research on autonomous flight of micro air vehicles. Autonomous drone races stimulate the advances in this area by representing a very challenging case with tight turns, texture-less floors, and dynamic spectators around the track. These properties hamper...

journal article 2019

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Pressure Output Feedback Control of Tollmien–Schlichting Waves in Falkner–Skan Boundary Layers

Tol, H.J. (author), Kotsonis, M. (author), de Visser, C.C. (author)

This paper investigates the use of point wall pressure measurements for output feedback control of Tollmien–Schlichtingwaves in Falkner–Skan boundary layers.Anewapproach is presented for input–outputmodeling of the linear dynamics of the fluid system and the integration withH2∕Linear Quadratic Gaussian reduced-order control design. The pressure...

journal article 2019

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Characterization of Thermospheric Vertical Wind Activity at 225- to 295-km Altitude Using GOCE Data and Validation Against Explorer Missions

Visser, T. (author), March, G. (author), Doornbos, E.N. (author), de Visser, C.C. (author), Visser, P.N.A.M. (author)

Recently, the horizontal and vertical cross wind at 225- to 295-km altitude were derived from linear acceleration measurements of the Gravity field and steady-state Ocean Circulation Explorer satellite. The vertical component of these wind data is compared to wind data derived from the mass spectrometers of the Atmosphere Explorer C and E and...

journal article 2019

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Safe Exploration Algorithms for Reinforcement Learning Controllers

Mannucci, T. (author), van Kampen, E. (author), de Visser, C.C. (author), Chu, Q. P. (author)

Self-learning approaches, such as reinforcement learning, offer new possibilities for autonomous control of uncertain or time-varying systems. However, exploring an unknown environment under limited prediction capabilities is a challenge for a learning agent. If the environment is dangerous, free exploration can result in physical damage or in...

journal article 2018

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Torque model verication for the GOCE satellite

Visser, T. (author), Doornbos, E.N. (author), de Visser, C.C. (author), Visser, P.N.A.M. (author), Fritsche, Bent (author)

journal article 2018

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GPU implementation for spline-based wavefront reconstruction

Brunner, A.E. (author), de Visser, C.C. (author), Vuik, Cornelis (author), Verhaegen, M.H.G. (author)

This paper presents an adaptation of the distributed-spline-based aberration reconstruction method for Shack–Hartmann (SH) slope measurements to extremely large-scale adaptive optics systems and the execution on graphics processing units (GPUs). The introduction of a hierarchical multi-level scheme for the elimination of piston offsets between...

journal article 2018

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Effects of structural failure on the safe flight envelope of aircraft

Nabi, H.N. (author), Lombaerts, T.J.J. (author), Zhang, Y. (author), van Kampen, E. (author), Chu, Q. P. (author), de Visser, C.C. (author)

The research presented in this paper focuses on the effects of structural failures on the safe flight envelope of an aircraft, which is the set of all the states in which safe maneuver of the aircraft can be assured. Nonlinear reachability analysis basedonan optimal control formulation is performed to estimate the safe flight envelope using...

journal article 2018

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Aircraft Damage Identification and Classification for Database-driven Online Safe Flight Envelope Prediction

Zhang, Y. (author), de Visser, C.C. (author), Chu, Q. P. (author)

Safe flight-envelope prediction is essential for preventing aircraft loss of control after the occurrence of sudden structural damage and aerodynamic failures. Considering the unpredictable nature of such failures, many challenges remain in the process of implementing such a prediction system. In this paper, an approach to online safe flight...

journal article 2018

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Global Linear Parameter-Varying Modeling of Flapping-Wing Dynamics Using Flight Data

Armanini, S.F. (author), Karasek, M. (author), de Visser, C.C. (author)

Taking full advantage of the favorable flight properties of biologically inspired flapping-wing micro aerial vehicles requires having insight into their dynamics and providing adequate control in all flight conditions. Because of the high complexity of flapping flight and limited availability of accurate flight data, however, global models are...

journal article 2018

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High-Speed Flight of Quadrotor Despite Loss of Single Rotor

Sun, Sihao (author), Sijbers, Leon (author), Wang, Xuerui (author), de Visser, C.C. (author)

In order to achieve high-speed flight of a damaged quadrotor with complete loss of a single rotor, a multiloop hybrid nonlinear controller is designed. By fully making use of sensor measurements, the model dependence of this control method is reduced, which is conducive to handling disturbance from the unknown aerodynamic effects. This...

journal article 2018

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Localised estimation and control of linear instabilities in two-dimensional wall-bounded shear flows

Tol, H.J. (author), Kotsonis, M. (author), de Visser, C.C. (author), Bamieh, B. (author)

A new framework is presented for estimation and control of instabilities in wall-bounded shear flows described by the linearised Navier-Stokes equations. The control design considers the use of localised actuators/sensors to account for convective instabilities in an optimal control framework. External sources of disturbances are assumed to...

journal article 2017

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Onboard/Offboard Sensor Fusion for High-Fidelity Flapping-Wing Robot Flight Data

Armanini, S.F. (author), Karasek, M. (author), de Croon, G.C.H.E. (author), de Visser, C.C. (author)

journal article 2017

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Framework for Simultaneous Sensor and Actuator Fault-Tolerant Flight Control

Lu, P. (author), van Kampen, E. (author), de Visser, C.C. (author), Chu, Q. P. (author)

journal article 2017