Pilot modelling for airframe loads analysis

The development of large lightweight airframes has resulted in what used to be high frequency structural dynamics entering the low frequency range associated with an aircraft’s rigid body dynamics. This has led to the potential of adverse interactions between the aeroelastic effects and flight control, especially unwanted when incidents involving failures or extreme atmospheric disturbances occur. Moreover, the pilot’s response in such circumstances may not be reproducible in simulators and unique to the incident. The research described in this thesis describes the development of a pilot model suitable for the investigation of the effects of aeroelasticity on manual control and the study of the resulting airframe loads. After a review of the state-ofthe- art in pilot modelling an experimental approach involving desktop based pilot-in-the-loop simulation was adopted together with an optimal control based control-theoretic pilot model. The experiments allowed the investigation of manual control with a nonlinear flight control system and the derivation of parameter bounds for single-input-single-output pilot models. It was found that pilots could introduce variations of around 15 dB at the resonant frequency of the open loop pilot-vehicle-system. Sensory models suitable for the simulation of spatial disorientation effects were developed together with biomechanical models necessary to capture biodynamic feedthrough effects. A detailed derivation and method for the application of the modified optimal control pilot model, used to generate pilot control action, has also been shown in the contexts of pilot-model-in-the-loop simulations of scenarios involving an aileron failure and a gust encounter. It was found that manual control action particularly exacerbated horizontal tailplane internal loads relative to the limit loads envelope. Although comparisons with digital flight data recordings of an actual gust encounter showed a satisfactory reproduction and highlighted the adverse affects of fuselage flexibility on manual control, it also pointed towards the need for more incident data to validate such simulations

Relating biodynamic feedthrough to neuromuscular admittance

Biodynamic feedthrough (BDFT) refers to a phenomenon where accelerations cause involuntary limb motions which, when coupled to a control device, can result in unintentional control inputs. The goal of this study is to increase the understanding of biodynamic feedthrough, with a focus on the influence of the neuromuscular system. Biodynamic feedthrough has been studied for many years, but its fundamental processes are only poorly understood. Many factors were reported to play a role in the occurrence of biodynamic feedthrough and many of these show mutual interactions. In several studies it was mentioned that the parameters of the neuromuscular system influence the occurrence of BDFT and that these can differ from person to person (inter-subject variability). However, only very little studies have recognized the variability in neuromuscular settings that a single person can express (intra-subject variability) and no known research was devoted to investigating this relation to date. In this study, it was hypothesized that BDFT is strongly influenced by the setting of the neuromuscular system, i.e. the neuromuscular admittance. This hypothesis was tested by performing an experiment in which both the neuromuscular admittance and the biodynamic feedthrough were measured using a motion-based simulator. The neuromuscular admittance was varied using three control tasks, each requiring a different level of admittance. The simultaneous measurement of admittance and biodynamic feedthrough was made possible by offering two disturbance signals that were separated in the frequency domain. The results show a strong dependency of biodynamic feedthrough (BDFT) on neuromuscular admittance. The obtained experimental data was used to develop a biodynamic feedthrough model, capable of describing BDFT for various settings of the neuromuscular system. The BDFT model was constructed by augmenting a neuromuscular model to account for the effect of motion disturbances. An advantage of the proposed modeling approach is that it considerably simplifies the process of parameterization of the BDFT model. In comparison to the measured data, the model proved to describe BDFT dynamics correctly for different subjects and different settings of the neuromuscular system, both in the frequency and in the time domain. However, the parameter values do not readily agree with results that were expected based on theory. Further research is required to investigate the implications of the model approach to the model's physical interpretability

Relating biodynamic feedthrough to neuromuscular admittance

When an operator in a moving vehicle is performing a manual control task, the accelerations to which the operator is subjected can result in unintentional control inputs. This biodynamic feedthrough (BDFT) depends on the properties of the control device and of the control limb. Humans can adjust the dynamics properties of their limbs, effectively changing the limb admittance. Previous studies of BDFT did not consider the effect of this adjustment. This paper describes a model for BDFT and an experiment in a moving base simulator with subjects performing a control task with a side stick. During the experiment the neuromuscular admittance was varied by using different control tasks, each requiring a different neuromuscular setting. The non-parametric results of this experiment show that the level of feedthrough is strongly dependent on both the frequency of the disturbance and the neuromuscular admittance. The results furthermore suggest that a relationship can be established between admittance and biodynamic feedthrough

Aerospace Medicine and Biology: A cumulative index to the 1982 issues

This publication is a cumulative index to the abstracts contained in the Supplements 229 through 240 of Aerospace Medicine and Biology: A continuing Bibliography. It includes three indexes: subject, personal author, and corporate source

Multibody dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politècnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version

Relating biodynamic feedthrough to neuromuscular admittance: Understanding the effect of acceleration disturbances on manual control performance

Biodynamic feedthrough (BDFT) refers to a phenomenon where accelerations cause involuntary limb motions which, when coupled to a control device, can result in unintentional control inputs. The goal of this study is to increase the understanding of biodynamic feedthrough, with a focus on the influence of the neuromuscular system. Biodynamic feedthrough has been studied for many years, but its fundamental processes are only poorly understood. Many factors were reported to play a role in the occurrence of biodynamic feedthrough and many of these show mutual interactions. In several studies it was mentioned that the parameters of the neuromuscular system influence the occurrence of BDFT and that these can differ from person to person (inter-subject variability). However, only very little studies have recognized the variability in neuromuscular settings that a single person can express (intra-subject variability) and no known research was devoted to investigating this relation to date. In this study, it was hypothesized that BDFT is strongly influenced by the setting of the neuromuscular system, i.e. the neuromuscular admittance. This hypothesis was tested by performing an experiment in which both the neuromuscular admittance and the biodynamic feedthrough were measured using a motion-based simulator. The neuromuscular admittance was varied using three control tasks, each requiring a different level of admittance. The simultaneous measurement of admittance and biodynamic feedthrough was made possible by offering two disturbance signals that were separated in the frequency domain. The results show a strong dependency of biodynamic feedthrough on neuromuscular admittance. The obtained experimental data was used to develop a biodynamic feedthrough model, capable of describing BDFT for various settings of the neuromuscular system. The BDFT model was constructed by augmenting a neuromuscular model to account for the effect of motion disturbances. An advantage of the proposed modeling approach is that it considerably simplifies the process of parameterization of the BDFT model. In comparison to the measured data, the model proved to describe BDFT dynamics correctly for different subjects and different settings of the neuromuscular system, both in the frequency and in the time domain. However, the parameter values do not readily agree with results that were expected based on theory. Further research is required to investigate the implications of the model approach to the model’s physical interpretability.Aerospace EngineeringControl & Operation