Sophie F. Armanini
Delft University of Technology
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Publication
Featured researches published by Sophie F. Armanini.
Journal of Guidance Control and Dynamics | 2016
Sophie F. Armanini; C. C. de Visser; G. C. H. E. de Croon; M. Mulder
A time-varying model for the forward flight dynamics of a flapping-wing micro aerial vehicle is identified from free-flight optical tracking data. The model is validated and used to assess the validity of the widely applied time-scale separation assumption. Based on this assumption, each aerodynamic force and moment is formulated as a linear addition of decoupled time-averaged and time-varying submodels. The resulting aerodynamic models are incorporated in a set of linearized equations of motion, yielding a simulation-capable full dynamic model. The time-averaged component includes both the longitudinal and the lateral aerodynamics and is assumed to be linear. The time-varying component is modeled as a third-order Fourier series, which approximates the flapping dynamics effectively. Combining both components yields a more complete and realistic simulation. Results suggest that while in steady flight the time-scale separation assumption applies well during maneuvers the time-varying dynamics are not fully ...
AIAA Atmospheric Flight Mechanics Conference | 2015
Sophie F. Armanini; Coen C. de Visser; Guido C. H. E. de Croon
This paper presents the development of black-box linear state-space models for the flight dynamics of a flapping-wing micro aerial vehicle (FWMAV), the DelFly. The models were obtained by means of system identification techniques applied to flight data recorded in a motion tracking chamber and describe the time-averaged dynamics of the vehicle in the proximity of specific stationary points in forward flight. Ordinary least squares and maximum likelihood-based estimation approaches were applied in the time domain, and decoupled models were identified for the longitudinal and the lateral dynamics. The availability of several different datasets additionally allowed for validation and for the estimation and comparison among each other of several separate models. Adequate models were obtained for both the longitudinal and the lateral dynamics. These reproduce the estimation data well and are also capable of predicting the response to validation inputs with a reasonable degree of accuracy, thus allowing for a simulation of the DelFly near the stationary points considered. The identified dynamics are stable and thus in agreement with the observed behaviour of the DelFly in the considered flight regime.
intelligent robots and systems | 2016
Matej Karasek; Andries Koopmans; Sophie F. Armanini; B. D. W. Remes; Guido C. H. E. de Croon
Despite an intensive research on flapping flight and flapping wing MAVs in recent years, there are still no accurate models of flapping flight dynamics. This is partly due to lack of free flight data, in particular during manoeuvres. In this work, we present, for the first time, a comparison of free flight forces estimated using solely an on-board IMU with wind tunnel measurements. The IMU based estimation brings higher sampling rates and even lower variation among individual wingbeats, compared to what has been achieved with an external motion tracking system in the past. A good match was found in comparison to wind tunnel measurements; the slight differences observed are attributed to clamping effects. Further insight was gained from the on-board rpm sensor, which showed motor speed variation of ± 15% due to load variation over a wingbeat cycle. The IMU based force estimation represents an attractive solution for future studies of flapping wing MAVs as, unlike wind tunnel measurements, it allows force estimation at high temporal resolutions also during manoeuvres.
Bioinspiration & Biomimetics | 2016
Sophie F. Armanini; J V Caetano; G. C. H. E. de Croon; C. C. de Visser; M. Mulder
Flapping-wing aerodynamic models that are accurate, computationally efficient and physically meaningful, are challenging to obtain. Such models are essential to design flapping-wing micro air vehicles and to develop advanced controllers enhancing the autonomy of such vehicles. In this work, a phenomenological model is developed for the time-resolved aerodynamic forces on clap-and-fling ornithopters. The model is based on quasi-steady theory and accounts for inertial, circulatory, added mass and viscous forces. It extends existing quasi-steady approaches by: including a fling circulation factor to account for unsteady wing-wing interaction, considering real platform-specific wing kinematics and different flight regimes. The model parameters are estimated from wind tunnel measurements conducted on a real test platform. Comparison to wind tunnel data shows that the model predicts the lift forces on the test platform accurately, and accounts for wing-wing interaction effectively. Additionally, validation tests with real free-flight data show that lift forces can be predicted with considerable accuracy in different flight regimes. The complete parameter-varying model represents a wide range of flight conditions, is computationally simple, physically meaningful and requires few measurements. It is therefore potentially useful for both control design and preliminary conceptual studies for developing new platforms.
2018 AIAA Atmospheric Flight Mechanics Conference | 2018
Frank G. Rijks; Matej Karasek; Sophie F. Armanini; Coen C. de Visser
The effects of the horizontal tail surface on the longitudinal dynamics of an or- nithopter were studied by systematically varying its surface area, aspect ratio and its longitudinal position. The objective is to improve the understanding of the tail effect on the behaviour of the ornithopter and to assess if simple models based on tail geometry can predict steady-state conditions and dynamic behaviour. A data- driven approach was adopted since no suitable theoretical models for ornithopter tail aerodynamics are available. Data was obtained through wind tunnel and free-flight experiments. Fourteen tail geometries were tested, at four positions with respect to the fl apping wings. Linearised models were used to study the effects of the tail on dynamic behaviour. The data shows that, within the tested ranges, increasing surface area or aspect ratio increases the steady-state velocity of the platform and improves pitch damping. Results also suggest that the maximum span width of the tail significantly influences the damping properties, especially when the distance between the tail and the flapping wings is large, which likely relates to the induced velocity profile of the flapping wings. Steady-state conditions can be predicted accurately based on tail geometry even when extrapolated slightly outside the original measurement range. Some trends were identified between model parameters and tail geometry, but more research is required before these trends can be applied as a design tool.
2018 AIAA Modeling and Simulation Technologies Conference | 2018
Sophie F. Armanini; Matej Karasek; Coen C. de Visser
Biologically-inspired flapping-wing micro aerial vehicles are characterised by nonlinear, unsteady aerodynamics and complex dynamics, both highly challenging to model. To take full advantage of the flight capabilities of such vehicles, it is necessary to obtain insight into their dynamics in the different flyable conditions, and to provide adequate control in all of these conditions. Nonetheless, the dynamics are typically only considered in a single flight regime, and controllers are frequently tuned for a particular flight condition. Due to the high complexity of flapping flight and limited availability of accurate free-flight data, global models are not yet readily available, particularly models based on free-flight data and suitable for practical applications. This paper demonstrates an approach to obtain a global dynamic model for a flapping-wing micro aerial vehicle. To allow for standard linear control and systems theory to be applied, the nonlinear dynamics are approximated using a linear parameter-varying (LPV) approach based on a set of local linear models. The scheduling parameters, and the parameters in the underlying local models, are determined using system identification methods applied to free-flight data collected on a real test platform, and covering a significant part of the flight envelope. The proposed approach allows for modelling of the vehicle and prediction of the dominant dynamic properties across the considered part of the flight envelope, using a total of 16 parameters, as opposed to the starting point of 46 local models with 12 parameters each. The use of a single model adapting to the flight condition provides flexibility and continuous coverage, and is therefore highly useful for simulation and control applications. While in the explored part of the flight envelope the nonlinearity was found to be limited, such that a weighted average model may be sufficient for some applications, the LPV model provides a higher accuracy and more consistent performance across the conditions considered. Additionally, the approach is shown to be promising and is expected to be adaptable to cover more significant variation. Improvements could be obtained through more extensive flight envelope coverage, more accurate measurement and more informative identification data.
2018 AIAA Information Systems-AIAA Infotech @ Aerospace | 2018
Menno Goedhart; Erik-Jan Van Kampen; Sophie F. Armanini; Coen C. de Visser; Q Ping Chu
Flight control of Flapping Wing Micro Air Vehicles is challenging, because of their complex dynamics and variability due to manufacturing inconsistencies. Machine Learning algorithms can be used to tackle these challenges. A Policy Gradient algorithm is used to tune the gains of a Proportional-Integral controller using Reinforcement Learning. A novel Classification Algorithm for Machine Learning control (CAML) is presented, which uses model identification and a neural network classifier to select from several predefined gain sets. The algorithms show comparable performance when considering variability only, but the Policy Gradient algorithm is more robust to noise, disturbances, nonlinearities and flapping motion. CAML seems to be promising for problems where no single gain set is available to stabilize the entire set of variable systems.
international conference on unmanned aircraft systems | 2017
J.V. Caetano; Sophie F. Armanini; M. Karasek
Although flapping-wing micro aerial vehicles have become a hot topic in academia, the knowledge we have of these systems, their force generation mechanisms and dynamics is still limited. Recent technological advances have allowed for the development of free flight test setups using on-board sensors and external tracking systems, for system identification purposes. Nevertheless, there is still little knowledge about the system requirements, as well as on how to perform free flight test experiments, and process the collected data. The present article presents the guidelines for flapping-wing micro aerial vehicle free flight testing. In particular, it gathers information produced by different studies and provides the best practices for the proper system dimensioning, system setup, on-board sensors, maneuver input design, error analyses and data post-processing, for the reconstruction of the forces and moments that act during free flight of a flapping-wing robot, for system identification and modeling purposes. Furthermore, this article compares the results obtained using external optical position tracking systems with on-board and external sensor fusion, and provides suitable solutions and methods for data fusion and force reconstruction.
IMAV 2014: International Micro Air Vehicle Conference and Competition 2014, Delft, The Netherlands, August 12-15, 2014 | 2014
Sophie F. Armanini; J.L. Verboom; G. C. H. E. de Croon; C. C. de Visser
This paper presents the results of a series of flight tests conducted in order to assess the steady-state flight characteristics and basic control behaviour of the DelFly, a flapping-wing micro aerial vehicle (FWMAV). Flights were conducted in an indoor motion tracking facility and included steady-level flight at a range of different velocities and turn manoeuvres. A number of different trim points were determined and approximate trim curves constructed to describe elevator effectiveness. Aileron effectiveness was then evaluated in terms of resulting turn radii and turn rates. The results provide insight into some of the basic flight properties of the DelFly and represent a starting point for further modelling work. The flight testing process also highlighted some of the major issues to be addressed in order to obtain meaningful experimental results.
AIAA Atmospheric Flight Mechanics Conference | 2017
Sophie F. Armanini; Matej Karasek; Coen C. de Visser; Guido C. H. E. de Croon; Max Mulder