@Poster{ SymeonidouOVBC2016, title = {EEG oscillatory modulations (10-12 Hz) discriminate for voluntary motor control and limb movement}, year = {2016}, month = {11}, day = {13}, number = {156.07}, abstract = {The oscillatory suppression of sensorimotor-mu power (i.e., 10-12 Hz) is a robust EEG correlate of motor control. Simply imagining voluntary limb movement can result in consistent suppression of mu-power, especially in contralateral electrode sites. This is typically exploited by neuroprostheses (e.g., BCI-controlled wheelchairs; Huang et al., 2012) that seek to restore movement to spinal-cord injury patients. In some examples, levels of mu-suppression have also been treated as an index of motor control effort (e.g., Mann et al., 1996). However, mu-suppression in contralateral sites can also be observed during passive limb movements, namely in the absence of voluntary control effort (Formaggio et al., 2013). In this study, we investigate whether patterns of oscillatory EEG activity across contralateral (C3) and ipsilateral (C4) sites discriminate for voluntary control and limb movement. In our study, EEG measurements were taken of ten participants who were required to either actively follow or resist the deflections of a control-loaded side-stick, this respectively required voluntary control in the presence and absence of limb movement. In contrast, they were also tested in conditions with passive or no limb movements, which respectively required them to simply hold on to a moving or stationary side-stick. A repeated-measures 2 x 2 x 2 ANOVA for the factors of electrode site (contralateral vs. ipsilateral), control (active vs. passive), and movement (movement vs stationary) revealed the following. To begin, there was a significant main effect of lateralized mu-suppression. Suppression of mu-power is larger in the contralateral site compared to the ipsilateral site (F(1,9)=5.10, p=0.05). More importantly, three significant interactions were found, movement x control (F(1,9)=13.1, p<0.01), electrode x movement (F(1,9)=5.78, p=0.04) and for electrode x control (F(1,9)=5.81, p=0.039). Limb movement resulted in selective mu-suppression of only the contralateral electrode. Voluntary control resulted in mu-suppression in both contralateral and ipsilateral electrodes, albeit to a lesser extent in the ipsilateral site. Overall, active resistance against side-stick deflections resulted in the largest levels of mu-suppression. The current results suggest that active voluntary resistance can result in high levels of mu-suppression that do not exhibit strong lateralization. This might go unnoticed in brain-computer-interface and experimental paradigms that estimate control effort by contrasting contralateral to ipsilateral mu-suppression.}, web_url = {http://www.abstractsonline.com/pp8/index.html#!/4071/presentation/29083}, event_name = {46th Annual Meeting of the Society for Neuroscience (Neuroscience 2016)}, event_place = {San Diego, CA, USA}, state = {published}, author = {Symeonidou ER{esymeonidou}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Inproceedings{ D039IntinoOGVIBP2016, title = {Evaluation of Haptic Support System for Training Purposes in a Tracking Task}, year = {2016}, month = {10}, pages = {002169-002174}, abstract = {Haptic guidance has previously been employed to improve human performance in control tasks. This paper presents an experiment to evaluate whether haptic feedback can be used to help humans learn a compensatory tracking task. In the experiment, participants were divided into two groups: the haptic group and the no-aid group. The haptic group performed a first training phase with haptic feedback and a second evaluation phase without haptic feedback. The no-aid group performed the whole experiment without haptic feedback. Results indicated that haptic group achieved better performance than the no aid group during the training phase. Furthermore, performance of haptic group did not worsen in the evaluation phase when the haptic feedback was turned off. On the other hand, the no-aid group needed more experimental trials to achieve similar performance to the haptic group. These findings indicate that haptic feedback helped participants learn the task quicker.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7844560}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2016)}, event_place = {Budapest, Hungary}, state = {published}, ISBN = {978-1-5090-1897-0}, DOI = {10.1109/SMC.2016.7844560}, author = {D'Intino G{gdintino}{Department Human Perception, Cognition and Action}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; Innocenti M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Thesis{ D039Intino2016, title = {Design and Experimental Evaluation of Haptic Support Systems for Pilot Training}, year = {2016}, month = {9}, day = {29}, web_url = {https://etd.adm.unipi.it/t/etd-09072016-131529/}, state = {published}, type = {PhD}, author = {D'Intino G{gdintino}{Department Human Perception, Cognition and Action}} } @Article{ DropPVMB2016, title = {Objective Model Selection for Identifying the Human Feedforward Response in Manual Control}, journal = {IEEE Transactions on Cybernetics}, year = {2016}, month = {9}, volume = {Epub ahead}, abstract = {Realistic manual control tasks typically involve predictable target signals and random disturbances. The human controller (HC) is hypothesized to use a feedforward control strategy for target-following, in addition to feedback control for disturbance-rejection. Little is known about human feedforward control, partly because common system identification methods have difficulty in identifying whether, and (if so) how, the HC applies a feedforward strategy. In this paper, an identification procedure is presented that aims at an objective model selection for identifying the human feedforward response, using linear time-invariant autoregressive with exogenous input models. A new model selection criterion is proposed to decide on the model order (number of parameters) and the presence of feedforward in addition to feedback. For a range of typical control tasks, it is shown by means of Monte Carlo computer simulations that the classical Bayesian information criterion (BIC) leads to selecting models that contain a feedforward path from data generated by a pure feedback model: “false-positive” feedforward detection. To eliminate these false-positives, the modified BIC includes an additional penalty on model complexity. The appropriate weighting is found through computer simulations with a hypothesized HC model prior to performing a tracking experiment. Experimental human-in-the-loop data will be considered in future work. With appropriate weighting, the method correctly identifies the HC dynamics in a wide range of control tasks, without false-positive results.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7571161}, state = {published}, DOI = {10.1109/TCYB.2016.2602322}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; van Paassen MM; Mulder M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ VenrooijOB2016, title = {Biodynamic Feedthrough: Current Status and Open Issues}, journal = {IFAC-PapersOnLine}, year = {2016}, month = {8}, volume = {49}, number = {19}, pages = {120–125}, abstract = {Biodynamic feedthrough (BDFT) occurs when vehicle accelerations feed through the body of a human operator, causing involuntary limb motions, which in turn result in involuntary control inputs. Manual control of many different vehicles is known to be vulnerable to BDFT effects, such as that of helicopters, aircraft, electric wheelchairs and hydraulic excavators. This paper provides a brief review of BDFT literature, which serves as a basis for identifying the fundamental challenges that remain to be addressed in future BDFT research. One of these challenges, time-variant BDFT identification, is discussed in more detail. Currently, it is often assumed that BDFT dynamics are (quasi)linear and time-invariant. This assumption can only be justified when measuring BDFT under carefully crafted experimental conditions, which are very different from real-world situations. As BDFT dynamics depend on neuromuscular dynamics, they are typically time-varying. This paper investigates the suitability of a recently developed time-variant identification approach, based on a recursive least-squares algorithm, which has been successfully used to identify time-varying neuromuscular dynamics.}, file_url = {fileadmin/user_upload/files/publications/2016/IFAC-2016-Venrooij.pdf}, web_url = {http://www.sciencedirect.com/science/article/pii/S2405896316320626}, editor = {Sawaragi, T.}, publisher = {Elsevier}, address = {Frankfurt a.M., Germany}, event_name = {13th IFAC/IFIP/IFORS/IEA Symposium on Analysis, Design, and Evaluation of Human-Machine Systems (HMS 2016)}, event_place = {Kyoto, Japan}, state = {published}, DOI = {10.1016/j.ifacol.2016.10.472}, author = {Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ DropPMB2016, title = {Constraints in Identification of Multi-Loop Feedforward Human Control Models}, journal = {IFAC-PapersOnLine}, year = {2016}, month = {8}, volume = {49}, number = {19}, pages = {7-12}, abstract = {The human controller (HC) can greatly improve target-tracking performance by utilizing a feedforward operation on the target signal, in addition to a feedback response. System identification methods are used to determine the correct HC model structure: purely feedback or a combined feedforward/feedback model. In this paper, we investigate three central issues that complicate this objective. First, the identification method should not require prior assumptions regarding the dynamics of the feedforward and feedback components. Second, severe biases might be introduced by high levels of noise in the data measured under closed-loop conditions. To address the first two issues, we will consider two identification methods that make use of linear ARX models: the classic direct method and the two-stage indirect method of van den Hof and Schrama (1993). Third, model complexity should be considered in the selection of the ‘best’ ARX model to prevent ‘false-positive’ feedforward identification. Various model selection criteria, that make an explicit trade-off between model quality and model complexity, are considered. Based on computer simulations with a HC model, we conclude that 1) the direct method provides more accurate estimates in the frequency range of interest, and 2) existing model selection criteria do not prevent false-positive feedforward identification.}, web_url = {http://www.sciencedirect.com/science/article/pii/S2405896316320328}, editor = {Sawaragi, T.}, publisher = {Elsevier}, address = {Frankfurt a.M., Germany}, event_name = {13th IFAC/IFIP/IFORS/IEA Symposium on Analysis, Design, and Evaluation of Human-Machine Systems (HMS 2016)}, event_place = {Kyoto, Japan}, state = {published}, DOI = {10.1016/j.ifacol.2016.10.444}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; Mulder M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ PolliniROBMPPNIB2016, title = {Design, Realization and Experimental Evaluation of a Haptic Stick for Shared Control Studies}, journal = {IFAC-PapersOnLine}, year = {2016}, month = {8}, volume = {49}, number = {19}, pages = {78–83}, abstract = {Shared control is becoming widely used in many manual control tasks as a mean for improving performance and safety. Designing an effective shared control system requires extensive testing and knowledge of how operators react to the haptic sensations provided by the control device shared with the support system. Commercial general purpose haptic devices may be unfit to reproduce the operational situation typical of the control task under study, like car driving or airplane flying. Thus specific devices are needed for research on specific task; this market niche exists but is characterized by expensive products. This paper presents the development of a complete low cost haptic stick, of its initial characterization and inner loop and impedance control systems design, and finally proposes an evaluation with two test cases: pilot admittance identification with the classical tasks, and an entire haptic experiment. In particular this latter experiment tries to study what happens when a system failure happens in a pilot support system built using a classical embedded controller, compared to a system built following the haptic shared control paradigm.}, web_url = {http://www.sciencedirect.com/science/article/pii/S2405896316320559}, editor = {Sawaragi, T.}, publisher = {Elsevier}, address = {Frankfurt a.M., Germany}, event_name = {13th IFAC/IFIP/IFORS/IEA Symposium on Analysis, Design, and Evaluation of Human-Machine Systems (HMS 2016)}, event_place = {Kyoto, Japan}, state = {published}, DOI = {10.1016/j.ifacol.2016.10.465}, author = {Pollini L; Razzanelli M; Olivari M{molivari}{Department Human Perception, Cognition and Action}; Brandimarti A; Maimeri M; Pazzaglia P; Pittiglio G; Nuti R; Innocenti M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ DropDMB2016, title = {The Predictability of a Target Signal Affects Manual Feedforward Control}, journal = {IFAC-PapersOnLine}, year = {2016}, month = {8}, volume = {49}, number = {19}, pages = {177–182}, abstract = {In the manual control of a dynamic system, the human controller (HC) is often required to follow a visible and predictable reference path. Using the predictable aspect of a reference signal, through applying feedforward control, the HC can significantly improve performance as compared to a purely feedback control strategy. A proper definition of a signal’s predictability, however, is never given in literature. This paper investigates the predictability of a sum-of-sinusoids target signal, as a function of the number of sinusoid components and the fact whether the sinusoid frequencies are harmonic, or not. A human-in-the-loop experiment was done, with target signals varying for these two signal characteristics. A combined feedback-feedforward HC model was identified and parameters were estimated. It was found that for all experimental conditions, subjects used a feedforward strategy. Results further showed that subjects were able to perform better for harmonic signals as compared to non-harmonic signals, for signals with roughly the same frequency content.}, web_url = {http://www.sciencedirect.com/science/article/pii/S2405896316320729}, editor = {Sawaragi, T.}, publisher = {Elsevier}, address = {Frankfurt a.M., Germany}, event_name = {13th IFAC/IFIP/IFORS/IEA Symposium on Analysis, Design, and Evaluation of Human-Machine Systems (HMS 2016)}, event_place = {Kyoto, Japan}, state = {published}, DOI = {10.1016/j.ifacol.2016.10.482}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; De Vries R{rdevries}{Department Human Perception, Cognition and Action}; Mulder M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ RoggenkamperPDvM2016, title = {Objective ARX Model Order Selection for Multi-Channel Human Operator Identification}, year = {2016}, month = {6}, day = {16}, pages = {787-803}, abstract = {Fundamental research carried out by McRuer et al. 1, 2 in the 1960s still forms the basis for the mathematical representation of pilot-vehicle systems today. Expressing human skills in the same control engineering terms as the vehicle to be controlled enables scientists to quantitatively evaluate human operators' manual control behavior. Decades of research have not only proven the validity of functional models as accurate descriptions of human tracking behavior during compensatory tracking tasks, 2–5 but also the suitability of ...}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2016-4299}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference: Held at the AIAA Aviation Forum 2016}, event_place = {Washington, DC, USA}, state = {published}, ISBN = {978-1-5108-2734-9}, DOI = {10.2514/6.2016-4299}, author = {Roggenk\"amper N; Pool DM{dpool}{Department Human Perception, Cognition and Action}; Drop FM{fdrop}{Department Human Perception, Cognition and Action}; van Paassen MM; Mulder M} } @Thesis{ Olivari2016, title = {Measuring Pilot Control Behavior in Control Tasks with Haptic Feedback}, year = {2016}, month = {6}, web_url = {https://etd.adm.unipi.it/t/etd-06012016-151319/}, state = {published}, type = {PhD}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}} } @Inproceedings{ PicardiGOB2016, title = {L1-based Model Following Control of an Identified Helicopter Model in Hover}, year = {2016}, month = {5}, pages = {1770-1777}, abstract = {The aim of this study is to augment the uncertain dynamics of the helicopter in order to resemble the dynamics of a new kind of vehicle, the so called Personal Aerial Vehicle. To achieve this goal a two step procedure is proposed. First, the helicopter model dynamics is augmented with a PID-based dynamic controller. Such controller implements a model following on the nominal helicopter model without uncertainties. Then, an L1 adaptive controller is designed to restore the nominal responses of the augmented helicopter when variations in the identified parameters are considered. The performance of the adaptive controller is evaluated via Montecarlo simulations. The results show that the application of the adaptive controller to the augmented helicopter dynamics can significantly reduce the effects of uncertainty due to the identification of the helicopter model. For implementation reasons the adaptive controller was applied to a subset of the outputs of the system. However, the under actuation typical of helicopters makes the tracking of the nominal responses good also on the not directly adapted outputs.}, web_url = {https://vtol.org/store/product/l1based-model-following-control-of-an-identified-helicopter-model-in-hover-11466.cfm}, publisher = {Curran}, address = {Red Hook, NY, USA}, booktitle = {Leveraging Emerging Technologies for Future Capabilities}, event_name = {72nd American Helicopter Society International Annual Forum (AHS 2016)}, event_place = {West Palm Beach, FL, USA}, state = {published}, ISBN = {978-1-5108-2506-2}, author = {Picardi G{gpicardi}{Department Human Perception, Cognition and Action}; Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GerboniVNJF2016, title = {Control Augmentation Strategies for Helicopters used as Personal Aerial Vehicles in Low-speed Regime}, year = {2016}, month = {1}, pages = {1002-1012}, abstract = {In this paper an augmentation strategy is implemented with the goal of making the behavior of an actual helicopter similar to that of a new class of aerial systems called Personal Aerial Vehicles (PAVs). PAVs are meant to be own by flight-naïve pilots, i.e., pilots with minimal flight experience. One feature required for achieving this goal, is to have a Translation Rate Command (TRC) response type in the hover and low-speed regime. In this paper, a TRC response type is obtained for a UH-60 helicopter simulation model in hover and low-speed regime through the implementation of nonlinear back stepping control. The responses of the rotorcraft with TRC response type are evaluated with the metrics defined in the Aeronautical Design Standard ADS-33. E-PRF. Simulations show the efficiency of the control scheme in tracking the reference velocities and the achievement of the requirements to have level 1 Handling Qualities (HQ) for the TRC response type.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2016-2137}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference: Held at the AIAA SciTech Forum 2016}, event_place = {San Diego, CA, USA}, state = {published}, ISBN = {978-1-5108-2065-4}, DOI = {10.2514/6.2016-2137}, author = {Gerboni CA{cgerboni}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Joos A; Fichter W; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OlivariVNPB2016, title = {Identifying Time-Varying Pilot Responses: A Regularized Recursive Least-Squares Algorithm}, year = {2016}, month = {1}, pages = {385-399}, abstract = {Methods for identifying pilot's responses commonly assume time-invariant dynamics. However, humans are likely to vary their responses during realistic control scenarios. In this work an identification method is developed for estimating time-varying responses to visual and force feedback during a compensatory tracking task. The method describes pilot's responses with finite impulse response filters and use a Regularized Recursive Least Squares (RegRLS) algorithm to simultaneously estimate filter coefficients. The method was validated in a Monte-Carlo simulation study with different levels of remnant noise. With low levels of remnant noise, estimates were accurate and tracked the time-varying behaviour of the simulated responses. On the other hand, estimates showed high variability in case of large remnant noise. However, parameters of the RegRLS could be further optimized to improve robustness to large remnant noise. Taken together, these findings suggest that the novel RegRLS algorithm could be used to estimate time-varying pilot's responses in real human-in-the-loop experiments.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2016-1182}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference: Held at the AIAA SciTech Forum 2016}, event_place = {San Diego, CA, USA}, state = {published}, ISBN = {978-1-5108-2065-4}, DOI = {10.2514/6.2016-1182}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Pollini L; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ GerboniNB2016, title = {Implementation and Validation of a 6 Degrees-of-Freedom Nonlinear Helicopter Model}, year = {2016}, month = {1}, pages = {1027-1040}, abstract = {The paper describes the implementation and validation of a nonlinear model of the UH-60 helicopter. The implemented model is based on a physical vehicle and includes various important subsystems in order to increase the model fidelity. The validation is carried out through a Handling Qualities (HQ) evaluation and a comparison with flight data. Various standardized tests have been performed in the time and frequency domain for hover and the forward flight condition. Results obtained have been analyzed according to the criteria defined by the Aeronautical Design Standard ADS-33E-PRF. The behavior of our helicopter model is very similar to flight test data of the UH-60 in hover and in forward flight, although some coupling effects are not well described. Overall the model provides a reliable basis for use in motion-base simulators and as framework for conducting studies on control augmentation systems.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2016-2139}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference: Held at the AIAA SciTech Forum 2016}, event_place = {San Diego, CA, USA}, state = {published}, ISBN = {978-1-5108-2065-4}, DOI = {10.2514/6.2016-2139}, author = {Gerboni CA{cgerboni}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ MaimeriOBP2016, title = {On Effects of Failures in Haptic and Automated Pilot Support Systems}, year = {2016}, month = {1}, pages = {373-384}, abstract = {External aids are required to increase safety and performance during the manual control of an aircraft. Automated systems allow to surpass the performance usually achieved by pilots. However, they suffer from several issues caused by pilot unawareness of the control command from the automation. Haptic aids can overcome these issues by showing their control command through forces on the control device. It is possible to design Haptic aids that allow pilots to improve performance compared with the baseline condition, even if these are usually outperformed by automation. It is not very well understood yet however, what happens to performance in the event of a failure of the Pilot support system. To investigate how and if a pilot can recovery its performance after a failure of the haptic or automated support system, a quantitative comparison is needed. An experiment was conducted in which pilots performed a compensatory tracking task with haptic aids and with automation. Half of the runs were affected by a failure of the support system, resulting in complete removal of the support action. The haptic aid and the automation were designed to be equivalent when the pilot was out-of-the-loop, i.e., to provide the same control command. Pilot performance and control effort were then evaluated with pilots in-the-loop and compared to a baseline condition without external aids. As expected pilots performance is better with the automated support system, than with Haptic when no failure happens. When a Failure happens, pilots experience a sudden decrease of performance in both cases, but loss of performance is much higher in the automation case. In addition and somehow surprisingly, after the initial loss of performance, pilots flying with the Haptic aid return approximately to the performance level they had just before the failure, while pilots flying with Automation cannot re-gain pre-failure levels of performance, at least in the time span of the experiment.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2016-1181}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference: Held at the AIAA SciTech Forum 2016}, event_place = {San Diego, CA, USA}, state = {published}, ISBN = {978-1-5108-2065-4}, DOI = {10.2514/6.2016-1181}, author = {Maimeri M; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Book{ Drop2016, title = {Control-Theoretic Models of Feedforward in Manual Control}, year = {2016}, pages = {300}, abstract = {Understanding how humans control a vehicle (cars, aircraft, bicycles, etc.) enables engineers to design faster, safer, more comfortable, more energy efficient, more versatile, and thus better vehicles. In a typical control task, the Human Controller (HC) gives control inputs to a vehicle such that it follows a particular reference path (e.g., the road) accurately. The HC is simultaneously required to attenuate the effect of disturbances (e.g., turbulence) perturbing the intended path of the vehicle. To do so, the HC can use a control organization that resembles a closed-loop feedback controller, a feedforward controller, or a combination of both. Previous research has shown that a purely closed-loop feedback control organization is observed only in specific control tasks, that do not resemble realistic control tasks, in which the information presented to the human is very limited. In realistic tasks, a feedforward control strategy is to be expected; yet, almost all previously available HC models describe the human as a pure feedback controller lacking the important feedforward response. Therefore, the goal of the research described in this thesis was to obtain a fundamental understanding of feedforward in human manual control. First, a novel system identification method was developed, which was necessary to identify human control dynamics in control tasks involving realistic reference signals. Second, the novel identification method was used to investigate three important aspects of feedforward through human-in-the-loop experiments which resulted in a control-theoretical model of feedforward in manual control. The central element of the feedforward model is the inverse of the vehicle dynamics, equal to the theoretically ideal feedforward dynamics. However, it was also found that the HC is not able to apply a feedforward response with these ideal dynamics, and that limitations in the perception, cognition, and action loop need to be modeled by additional model elements: a gain, a time delay, and a low-pass filter. Overall, the thesis demonstrated that feedforward is indeed an essential part of human manual control behavior and should be accounted for in many human-machine applications.}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=4354&lng=deu&id=}, publisher = {Logos Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 46}, state = {published}, ISBN = {978-3-8325-4354-9}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}} } @Book{ Geluardi2016, title = {Identification and augmentation of a civil light helicopter: transforming helicopters into Personal Aerial Vehicles}, year = {2016}, pages = {198}, abstract = {The research described in this thesis was inspired by the results of the myCopter project, a European project funded by the European Commission in 2011. The myCopter project's aim was to identify new concepts for air transport that could be used to achieve a Personal Aerial Transport (PAT) system in the second half of the 21st century. Although designing a new vehicle was not among the project's goal, it was considered important to assess vehicle response types and handling qualities that Personal Aerial Vehicles (PAVs) should have to be part of a PAT. In this thesis it is proposed to consider civil light helicopters as possible PAVs candidates. The goal of the thesis is to investigate whether it is possible to transform civil light helicopters into PAVs through the use of system identification methods and control techniques. The transformation here is envisaged in terms of vehicle dynamics and handling qualities. To achieve this goal, three main steps are considered. The first step focuses on the identification of a Robinson R44 Raven II helicopter model in hover. The second step consists of augmenting the identified helicopter model to achieve response types and handling qualities defined for PAVs. The third step consists of assessing the magnitude of discrepancy between the two implemented augmented systems and the PAV reference model. An experiment is conducted for this purpose, consisting of piloted closed-loop control tasks performed in the MPI CyberMotion Simulator by participants without any prior flight experience. Results, evaluated in terms of objective and subjective workload and performance, show that both augmented control systems are able to resemble PAVs handling qualities and response types in piloted closed-loop control tasks. This result demonstrates that it is possible to transform helicopter dynamics into PAVs dynamics.}, web_url = {http://www.logos-verlag.de/cgi-bin/engbuchmid?isbn=4366&lng=deu&id=}, publisher = {Logos Verlag}, address = {Berlin, Germany}, series = {MPI Series in Biological Cybernetics ; 47}, state = {published}, ISBN = {978-3-8325-4366-2}, author = {Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}} } @Article{ OlivariNVBP2013, title = {Methods for Multiloop Identification of Visual and Neuromuscular Pilot Responses}, journal = {IEEE Transactions on Cybernetics}, year = {2015}, month = {12}, volume = {45}, number = {12}, pages = {2780 - 2791}, abstract = {In this paper, identification methods are proposed to estimate the neuromuscular and visual responses of a multiloop pilot model. A conventional and widely used technique for simultaneous identification of the neuromuscular and visual systems makes use of cross-spectral density estimates. This paper shows that this technique requires a specific noninterference hypothesis, often implicitly assumed, that may be difficult to meet during actual experimental designs. A mathematical justification of the necessity of the noninterference hypothesis is given. Furthermore, two methods are proposed that do not have the same limitations. The first method is based on autoregressive models with exogenous inputs, whereas the second one combines cross-spectral estimators with interpolation in the frequency domain. The two identification methods are validated by offline simulations and contrasted to the classic method. The results reveal that the classic method fails when the noninterference hypothesis is not fulfilled; on the contrary, the two proposed techniques give reliable estimates. Finally, the three identification methods are applied to experimental data from a closed-loop control task with pilots. The two proposed techniques give comparable estimates, different from those obtained by the classic method. The differences match those found with the simulations. Thus, the two identification methods provide a good alternative to the classic method and make it possible to simultaneously estimate human's neuromuscular and visual responses in cases where the classic method fails.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7045541}, state = {published}, DOI = {10.1109/TCYB.2014.2384525}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Inproceedings{ GeluardiNPB2013, title = {Data Collection for Developing a Dynamic Model of a Light Helicopter}, year = {2015}, month = {10}, pages = {419-433}, abstract = {At the Max Planck Institute for Biological Cybernetics the influence of an augmented system on helicopter pilots with limited flight skills is being investigated. This study would provide important contributions in the research field on personal air transport systems. In this project, the flight condition under study is the hover. The first step is the implementation of a rigid-body dynamic model. This could be used to perform handling qualities evaluations for comparing the pilot performances with and without augmented system. This paper aims to provide a lean procedure and a reliable measurement setup for the collection of the flight test data. The latter are necessary to identify the helicopter dynamic model. The mathematical and technical tools used to reach this purpose are described in detail. First, the measurement setup is presented, used to collect the piloted control inputs and the helicopter response. Second, a description of the flight maneuvers and the pilot training phase is taken into consideration. Finally the flight test data collection is described and the results are showed to assess and validate the setup and the procedure presented.}, file_url = {fileadmin/user_upload/files/publications/2013/ERF-2013-Geluardi.pdf}, web_url = {https://vtol.org/events/39th-european-rotorcraft-forum-erf}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {39th European Rotorcraft Forum (ERF 2013)}, event_place = {Moskva, Russia}, state = {published}, ISBN = {978-1-5108-1007-5}, author = {Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Pollini L; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OlivariNBP2015_2, title = {Identifying Time-Varying Neuromuscular Response: a Recursive Least-Squares Algorithm with Pseudoinverse}, year = {2015}, month = {10}, pages = {3079-3085}, abstract = {Effectiveness of hap tic guidance systems depends on how humans adapt their neuromuscular response to the force feedback. A quantitative insight into adaptation of neuromuscular response can be obtained by identifying neuromuscular dynamics. Since humans are likely to vary their neuromuscular response during realistic control scenarios, there is a need for methods that can identify time-varying neuromuscular dynamics. In this work an identification method is developed which estimates the impulse response of time-varying neuromuscular system by using a Recursive Least Squares (RLS) method. The proposed method extends the commonly used RLS-based method by employing the pseudo inverse operator instead of the inverse operator. This results in improved robustness to external noise. The method was validated in a human in-the-loop experiment. The neuromuscular estimates given by the proposed method were more accurate than those obtained with the commonly used RLS-based method.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7379667}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2015)}, event_place = {Hong Kong, China}, state = {published}, ISBN = {978-1-4799-8696-5}, DOI = {10.1109/SMC.2015.535}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Inproceedings{ GerboniGONBP2014, title = {Development of a 6 dof nonlinear helicopter model for the MPI Cybermotion Simulator}, year = {2015}, month = {7}, pages = {615-626}, abstract = {This paper describes the different phases of realizing and validating a helicopter model for the MPI CyberMotion Simulator (CMS). The considered helicopter is a UH-60 Black Hawk. The helicopter model was developed based on equations and parameters available in literature. First, the validity of the model was assessed by performing tests based on ADS-33E-PRF criteria using closed loop controllers and with a non-expert pilot. Results on simulated data were similar to results obtained with the real helicopter. Second, the validity of the model was assessed with a helicopter pilot in-the-loop in both a fixed-base simulator and the CMS. The pilot performed a vertical remask maneuver defined in ADS-33E-PRF. Most metrics for performance were reached adequately with both simulators. The motion cues in the CMS allowed for improvements in some of the metrics. The pilot was also asked to give a subjective evaluation of the model by answering the Israel Aircraft Industries Pilot Rating Scale (IAI PRS). Similarly to results of ADS-33E-PRF, pilot responses confirmed that the motion cues provided more realistic flight experience.}, file_url = {fileadmin/user_upload/files/publications/2014/ERF-2014-Gerboni.pdf}, web_url = {http://www.ati.org.uk/event/40th-european-rotorcraft-forum-2014/}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {40th European Rotorcraft Forum (ERF 2014)}, event_place = {Southampton, UK}, state = {published}, ISBN = {978-1-5108-0256-8}, author = {Gerboni CA{cgerboni}{Department Human Perception, Cognition and Action}; Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Inproceedings{ GeluardiNPB2015, title = {Augmented Systems for a Personal Aerial Vehicle Using a Civil Light Helicopter Model}, year = {2015}, month = {5}, day = {6}, pages = {1428-1436}, abstract = {This paper presents the implementation of classic augmented control stategies applied to an identified civil light heli- copter model in hover. Aim of this study is to enhance the stability and controllability of the helicopter model and to improve its Handling Qualities (HQs) in order to meet those defined for a new category of aircrafts, Personal Aerial Vehicles (PAVs). Two control methods were used to develop the augmented systems, H-control and m-synthesis. The resulting augmented systems were compared in terms of achieved robust stability, nominal performance and robust performance. The robustness was evaluated against parametric uncertainties and external disturbances modeled as real atmospheric turbulences that might be experienced in hover and low speed flight. The main result achieved in this work is that classical control techniques can augment a linear helicopter model to match PAVs responses at low frequencies. As a consequence, the achieved HQs performance resemble those defined for PAVs pilots. However, both control techniques performed poorly for some specific uncertainty conditions demonstrating unsatisfactory per- formance robustness. Differences, advantages and limitations of the implemented control architectures with respect to the considered requirements are described in the paper.}, web_url = {https://vtol.org/store/product/augmented-systems-for-a-personal-aerial-vehicle-using-a-civil-light-helicopter-model-10174.cfm}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {71st American Helicopter Society International Annual Forum (AHS 2015)}, event_place = {Virginia Beach, VA, USA}, state = {published}, ISBN = {978-1-5108-0378-7}, author = {Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Pollini L; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Poster{ SymeonidouOBC2015, title = {Direct haptic feedback benefits control performance during steering}, year = {2015}, month = {3}, day = {10}, pages = {249-250}, abstract = {Haptic feedback can be introduced in control devices to improve steering performance, such as in driving and flying scenarios. For example, direct haptic feedback (DHF) can be employed to guide the operator towards an optimal trajectory. It remains unclear how DHF magnitude could interact with user performance. A weak DHF might not be perceptible to the user, while a large DHF could result in overreliance. To assess the influence of DHF, five naive participants performed a compensatory tracking task across different DHF magnitudes. During the task, participants were seated in front of an artificial horizon display and were asked to compensate for externally induced disturbances in the roll dimension by manipulating a control joystick. Our results indicate that haptic feedback benefits steering performance across all tested DHF levels. This benefit increases linearly with increasing DHF magnitude. Interestingly, shared control performance was always inferior to the same DHF system without human input. This could be due to involuntary resistance that results from the arm-dynamics.}, web_url = {https://www.teap.de/memory/TeaP_2015_Program2015-03-13.pdf}, event_name = {57th Conference of Experimental Psychologists (TeaP 2015)}, event_place = {Hildesheim, Germany}, state = {published}, author = {Symeonidou E-R{esymeonidou}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OlivariNBP2015, title = {Identifying Time-Varying Neuromuscular Response: Experimental Evaluation of a RLS-based Algorithm}, year = {2015}, month = {1}, pages = {284-298}, abstract = {Methods for identifying neuromuscular response commonly assume time-invariant neuromuscular dynamics. However, neuromuscular dynamics are likely to change during realistic control scenarios. In a previous paper we presented a method for identifying time-varying neuromuscular dynamics based on a Recursive Least Squares (RLS) algorithm. To date, this method has only been validated in a Monte Carlo simulation study. This paper presents an experimental validation of the same method. In the experiment, three different disturbance-rejection tasks were performed: a position task with the human instructed to minimize the stick deflection in front of an external force disturbance, a relax task with the instruction to relax the arm, and a time-varying task with the instruction to alternate between position and relax tasks. The position and relax tasks induce different time-invariant neuromuscular dynamics, whereas the time-varying task induces time-varying neuromuscular dynamics. The RLS-based method was used to estimate neuromuscular dynamics in the three tasks. The neuromuscular estimates were reliable both in time-invariant and time-varying tasks. These findings indicate that the RLS-based method can be used to estimate time-varying neuromuscular responses in human-in-the loop experiments.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2015-0658}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2015: Held at the SciTech Forum 2015}, event_place = {Kissimmee, FL, USA}, state = {published}, ISBN = {978-1-5108-0111-0}, DOI = {10.2514/6.2015-0658}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Article{ OlivariNBP2014_2, title = {Pilot Adaptation to Different Classes of Haptic Aids in Tracking Tasks}, journal = {Journal of Guidance, Control, and Dynamics}, year = {2014}, month = {11}, volume = {37}, number = {6}, pages = {1741-1753}, abstract = {Haptic aids have been largely used in manual control tasks to complement the visual information through the sense of touch. To analytically design a haptic aid, adequate knowledge is needed about how pilots adapt their visual response and the biomechanical properties of their arm (i.e., admittance) to a generic haptic aid. In this work, two different haptic aids, a direct haptic aid and an indirect haptic aid, are designed for a target tracking task, with the aim of investigating the pilot response to these aids. The direct haptic aid provides forces on the control device that suggest the right control action to the pilot, whereas the indirect haptic aid provides forces opposite in sign with respect to the direct haptic aid. The direct haptic aid and the indirect haptic aid were tested in an experimental setup with nonpilot participants and compared to a condition without haptic support. It was found that control performance improved with haptic aids. Participants significantly adapted both their admittance and visual response to fully exploit the haptic aids. They were more compliant with the direct haptic aid force, whereas they showed stiffer neuromuscular settings with the indirect haptic aid, as this approach required opposing the haptic forces.}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/1.G000534}, state = {published}, DOI = {10.2514/1.G000534}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen F{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Inproceedings{ OlivariNBP2014_3, title = {Identifying Time-Varying Neuromuscular System with a Recursive Least-Squares Algorithm: a Monte-Carlo Simulation Study}, year = {2014}, month = {10}, pages = {3573-3578}, abstract = {A human-centered design of haptic aids aims at tuning the force feedback based on the effect it has on human behavior. For this goal, a better understanding of the influence of haptic aids on the pilot neuromuscular response becomes crucial. In realistic scenarios, the neuromuscular response can continuously vary depending on many factors, such as environmental factors or pilot fatigue. This paper presents a method that online estimates time-varying neuromuscular dynamics during force-related tasks. This method is based on a Recursive Least Squares (RLS) algorithm and assumes that the neuromuscular response can be approximated by a Finite Impulse Response filter. The reliability and the robustness of the method were investigated by performing a set of Monte-Carlo simulations with increasing level or remnant noise. Even with high level of remnant noise, the RLS algorithm provided accurate estimates when the neuromuscular dynamics were constant or changed slowly. With instantaneous changes, the RLS algorithm needed almost 8s to converge to a reliable estimate. These results seem to indicate that RLS algorithm is a valid tool for estimating online time-varying admittance.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6974484}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man and Cybernetics (SMC 2014)}, event_place = {San Diego, CA, USA}, state = {published}, ISBN = {978-1-4799-3840-7}, DOI = {10.1109/SMC.2014.6974484}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Poster{ SymeonidouOBC2014, title = {The Role of Direct Haptic Feedback in a Compensatory Tracking Task}, journal = {Cognitive Processing}, year = {2014}, month = {9}, volume = {15}, number = {Supplement 1}, pages = {S71}, abstract = {Haptic feedback systems can be designed to assist vehicular steering by sharing manual control with the human operator. For example, direct haptic feedback (DHF) forces, that are applied over the control device, can guide the operator towards an optimized trajectory, which he can either augment, comply with or resist according to his preferences. DHF has been shown to improve performance (Olivari et al. submitted) and increase safety (Tsoi et al. 2010). Nonetheless, the human operator may not always benefit from the haptic support system. Depending on the amount of the haptic feedback, the operator might demonstrate an over- reliance or an opposition to this haptic assistance (Forsyth and MacLean 2006). Thus, it is worthwhile to investigate how different levels of haptic assistance influence shared control performance. The current study investigates how different gain levels of DHF influence performance in a compensatory tracking task. For this purpose, 6 participants were evenly divided into two groups according to their previous tracking experience. During the task, they had to compensate for externally induced disturbances that were visualized as the difference between a moving line and a horizontal reference standard. Briefly, participants observed how an unstable aircraft symbol, located in the middle of the screen, deviated in the roll axis from a stable artificial horizon. In order to compensate for the roll angle, participants were instructed to use the control joystick. Meanwhile, different DHF forces were presented over the control joystick for gain levels of 0, 12.5, 25, 50 and 100 %. The maximal DHF level was chosen according to the procedure described in (Olivari et al. 2014) and represents the best stable performance of skilled human operators. The participants’ performance was defined as the reciprocal of the median of the root mean square error (RMSE) in each condition. Figure 1a shows that performance improved with in- creasing DHF gain, regardless of experience levels. To evaluate the operator’s contribution, relative to the DHF contribution, we calculated the ratio of overall performance to estimated DHF performance without human input. Figure 1b shows that the subject’s contribution in both groups decreased with increasing DHF up to the 50 % condition. The contribution of experienced subjects plateaued between the 50 and 100 % DHF levels. Thus, the increase in performance for the 100 % condition can mainly be attributed to the higher DHF forces alone. In contrast, the inexperienced subjects seemed to completely rely on the DHF during the 50 % condition, since the operator’s contribution approximated 1. However, this changed for the 100 % DHF level. Here, the participants started to actively contribute to the task (operator’s contribution [1). This change in behavior resulted in performance values similar to those of the experienced group Our findings suggest that the increase of haptic support with our DHF system does not necessarily result in over-reliance and can improve performance for both experienced and inexperienced subjects.}, web_url = {http://link.springer.com/content/pdf/10.1007%2Fs10339-014-0632-2.pdf}, event_name = {12th Biannual Conference of the German Cognitive Science Society (KogWis 2014)}, event_place = {Tübingen, Germany}, state = {published}, DOI = {10.1007/s10339-014-0632-2}, author = {Symeonidou E-R{esymeonidou}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Poster{ SymeonidouOBC2014_2, title = {The Role of Direct Haptic Feedback in a Compensatory Tracking Task}, year = {2014}, month = {6}, web_url = {http://brain.korea.ac.kr/bce2014/?m=program}, event_name = {6th International Conference on Brain and Cognitive Engineering (BCE 2014)}, event_place = {Tübingen, Germany}, state = {published}, author = {Symeonidou E-R{esymeonidou}; Olivari M{molivari}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Chuang LL{chuang}{Department Human Perception, Cognition and Action}} } @Article{ CaitiCGGM2014, title = {Switching control of an underwater glider with independently controllable wings}, journal = {Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment}, year = {2014}, month = {5}, volume = {228}, number = {2}, pages = {136-145}, abstract = {The dynamic, control-oriented model of an underwater glider with independently controllable wings is presented. The onboard vehicle's actuators are a ballast tank and two hydrodynamic wings. A control strategy is proposed to improve the vehicle's maneuverability. In particular, a switching control law, together with a backstepping feedback scheme, is designed to limit the energy-inefficient actions of the ballast tank and hence to enforce efficient maneuvers. The case study considered here is an underwater vehicle with hydrodynamic wings behind its main hull. This unusual structure is motivated by the recently introduced concept of the underwater wave glider, which is a vehicle capable of both surface and underwater navigation. The proposed control strategy is validated via numerical simulations, in which the simulated vehicle has to perform three-dimensional path-following maneuvers.}, web_url = {http://pim.sagepub.com/content/228/2/136.abstract}, state = {published}, DOI = {10.1177/1475090213502001}, author = {Caiti A; Calabr{\`o} V; Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Grammatico S; Munaf{\`o} C} } @Inproceedings{ GeluardiNPB2014, title = {Frequency Domain System Identification of a Light Helicopter in Hover}, year = {2014}, month = {5}, pages = {1721-1731}, abstract = {This paper presents the implementation of a Multi-Input Single-Output fully coupled transfer function model of a civil light helicopter in hover. A frequency domain identification method is implemented. It is discussed that the chosen frequency range of excitation allows to capture some important rotor dynamic modes. Therefore, studies that require coupled rotor/body models are possible. The pitch-rate response with respect to the longitudinal cyclic is considered in detail throughout the paper. Different transfer functions are evaluated to compare the capability to capture the main helicopter dynamic modes. It is concluded that models with order less than 6 are not able to model the lead-lag dynamics in the pitch axis. Nevertheless, a transfer function model of the 4th order can provide acceptable results for handling qualities evaluations. The identified transfer function models are validated in the time domain with different input signals than those used during the identification and show good predictive capabilities. From the results it is possible to conclude that the identified transfer function models are able to capture the main dynamic characteristics of the considered light helicopter in hover.}, file_url = {fileadmin/user_upload/files/publications/2014/AHS-2014-Geluardi.pdf}, web_url = {https://vtol.org/store/product/frequency-domain-system-identification-of-a-light-helicopter-in-hover-9579.cfm}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {70th American Helicopter Society International Annual Forum (AHS 2014)}, event_place = {Montréal, QC, Canada}, state = {published}, ISBN = {978-1-63266-691-8}, author = {Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Pollini L; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ WiskemannDPvMB2014, title = {Subjective and Objective Metrics for the Evaluation of Motion Cueing Fidelity for a Roll-Lateral Reposition Maneuver}, year = {2014}, month = {5}, pages = {1706-1720}, abstract = {This paper describes an experiment conducted to investigate the effects of roll-lateral motion cueing algorithm settings on motion fidelity for helicopter roll-lateral repositioning tasks. A total of 13 motion conditions, comprising two roll gain settings, two degrees of roll-lateral coordination and three roll washout intensities, were tested by four pilots on the CyberMotion Simulator at the Max Planck Institute for Biological Cybernetics. An emphasis was put on the use of objective measurements for motion fidelity determination, in addition to collected subjective handling quality ratings (HQR) and motion fidelity ratings (MFS). Higher roll gains were found to have a beneficial effect on both the subjective and the objective metrics, which is in line with previous findings. Reducing the degree of coordination had a negative effect on subjective ratings, but did not show a consistent negative effect for the considered objective metrics. Stronger roll washout had a large and consistent negative effect on the subjective ratings. This is confirmed by the obtained objective measurements, which show high control activity and less realistic vehicle trajectories during the deceleration and stabilization phase of the maneuver for conditions with strong roll washout. We conclude that roll and lateral gain are more effective than roll washout to attenuate the simulated motion.}, file_url = {fileadmin/user_upload/files/publications/2014/AHS-2014-Drop.pdf}, web_url = {https://vtol.org/store/product/subjective-and-objective-metrics-for-the-evaluation-of-motion-cueing-fidelity-for-a-rolllateral-reposition-maneuver-9573.cfm}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {70th American Helicopter Society International Annual Forum (AHS 2014)}, event_place = {Montréal, QC, Canada}, state = {published}, ISBN = {978-1-63266-691-8}, author = {Wiskemann CM{mwiskemann}{Department Human Perception, Cognition and Action}; Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; van Paassen MM; Mulder M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Article{ CarpiFGGD2014, title = {Enabling variable-stiffness hand rehabilitation orthoses with dielectric elastomer transducers}, journal = {Medical Engineering & Physics}, year = {2014}, month = {2}, volume = {36}, number = {2}, pages = {205–211}, abstract = {Patients affected by motor disorders of the hand and having residual voluntary movements of fingers or wrist can benefit from self-rehabilitation exercises performed with so-called dynamic hand splints. These systems consist of orthoses equipped with elastic cords or springs, which either provide a sustained stretch or resist voluntary movements of fingers or wrist. These simple systems are limited by the impossibility of modulating the mechanical stiffness. This limitation does not allow for customizations and real-time control of the training exercise, which would improve the rehabilitation efficacy. To overcome this limitation, ‘active’ orthoses equipped with devices that allow for electrical control of the mechanical stiffness are needed. Here, we report on a solution that relies on compact and light-weight electroactive elastic transducers that replace the passive elastic components. We developed a variable-stiffness transducer made of dielectric elastomers, as the most performing types of electromechanically active polymers. The transducer was manufactured with a silicone film and tested with a purposely-developed stiffness control strategy that allowed for electrical modulations of the force–elongation response. Results showed that the proposed new technology is a promising and viable solution to develop electrically controllable dynamic hand orthoses for hand rehabilitation.}, web_url = {http://www.sciencedirect.com/science/article/pii/S1350453313002361}, state = {published}, DOI = {10.1016/j.medengphy.2013.10.015}, author = {Carpi F; Frediani G; Gerboni C{cgerboni}; Gemignani J; De Rossi D} } @Poster{ Geluardi2014, title = {Augmented Systems for Personal Air Vehicles}, year = {2014}, month = {1}, day = {9}, abstract = {Congestion problems in the transportation system have led to regulators considering implementing drastic changes in methods of transportation for the general public. A possible solution would be to combine the best of ground-based and air-based transportation and produce a personal air transport system. This project aims to investigate the interaction between a pilot with limited flying skills and augmented vehicles, that are part of the personal air transport system, and to verify if it is possible to reach similar performance to a highly-trained pilot, also in dangerous environmental or demanding conditions.}, web_url = {https://sites.google.com/a/dici.unipi.it/poster/2014/Poster_Geluardi.pdf}, event_name = {Presentazione attività anno 2013: Scuola di Ingegneria: Università di Pisa Dottorati di Ricerca in Automatica, Robotica e Bioingegneria, Ingegneria Meccanica, Ingegneria Chimica, Ingegneria Aerospaziale, Ingegneria Nucleare}, event_place = {Pisa, Italy}, state = {published}, author = {Geluardi S{sgeluardi}{Department Human Perception, Cognition and Action}} } @Poster{ Olivari2014, title = {Human-Centered Design of Haptic Aids for Aerial Vehicles}, year = {2014}, month = {1}, day = {9}, abstract = {Haptic aids have been largely used in manual control tasks to complement the visual information through the sense of touch. To analytically design the haptic aid, adequate knowledge is needed about how pilots adapt their visual response and the biomechanical properties of their arm to a generic haptic aid. Two novel identification methods were proposed to estimate the pilot dynamic responses. The two methods were applied to experimental data from closed-loop control tasks with pilots, with the aim of estimating the pilot responses to different external aids. Different haptic aids were designed and tested during the experiments: a Direct Haptic Aid (DHA) and an Indirect Haptic Aid (IHA). Furthermore, an automated system was designed to be equivalent to the haptic aids when the pilot was out-of-the-loop, i.e., to provide the same control command as the haptic aid. All the experimental conditions with the external aids were contrasted to a baseline condition without external aids.}, web_url = {https://sites.google.com/a/dici.unipi.it/poster/2014/Olivari_poster.pdf}, event_name = {Presentazione attività anno 2013: Scuola di Ingegneria: Università di Pisa Dottorati di Ricerca in Automatica, Robotica e Bioingegneria, Ingegneria Meccanica, Ingegneria Chimica, Ingegneria Aerospaziale, Ingegneria Nucleare}, event_place = {Pisa, Italy}, state = {published}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}} } @Inproceedings{ OlivariNBP2014, title = {An Experimental Comparison of Haptic and Automated Pilot Support Systems}, year = {2014}, month = {1}, pages = {163-173}, abstract = {External aids are required to increase safety and performance during the manual control of an aircraft. Automated systems allow to surpass the performance usually achieved by pilots. However, they suffer from several issues caused by pilot unawareness of the control command from the automation. Haptic aids can overcome these issues by showing their control command through forces on the control device. To investigate how the transparency of the haptic control action in uences performance and pilot behavior, a quantitative comparison between haptic aids and automation is needed. An experiment was conducted in which pilots performed a compensatory tracking task with haptic aids and with automation. The haptic aid and the automation were designed to be equivalent when the pilot was out-of-the-loop, i.e., to provide the same control command. Pilot performance and control effort were then evaluated with pilots in-the-loop and contrasted to a baseline condition without external aids. The haptic system allowed pilots to improve performance compared with the baseline condition. However, automation outperformed the other two conditions. Pilots control effort was reduced by the haptic aid and the automation in a similar way. In addition, the pilot open-loop response was estimated with a non-parametric estimation method. Changes in the pilot response were observed in terms of increased crossover frequency with automation, and decreased neuromuscular peak with haptics.}, file_url = {fileadmin/user_upload/files/publications/2014/SCITECH-2014-Olivari.pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2014-0809}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2014: Held at the SciTech Forum 2014}, event_place = {National Harbor, MD, USA}, state = {published}, ISBN = {978-1-63266-933-9}, DOI = {10.2514/6.2014-0809}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Thesis{ Gerboni2014, title = {Development of a 6 dof nonlinear helicopter model for the MPI Cybermotion Simulator}, year = {2014}, state = {published}, type = {Master}, author = {Gerboni CA{cgerboni}} } @Article{ DropPDVM2012, title = {Identification of the Feedforward Component of Manual Control in Tasks with Predictable Target Signals}, journal = {IEEE Transactions on Cybernetics}, year = {2013}, month = {12}, volume = {43}, number = {6}, pages = {1936-1949}, abstract = {In the manual control of a dynamic system, the human controller (HC) often follows a visible and predictable reference path. Compared with a purely feedback control strategy, performance can be improved by making use of this knowledge of the reference. The operator could effectively introduce feedforward control in conjunction with a feedback path to compensate for errors, as hypothesized in literature. However, feedforward behavior has never been identified from experimental data, nor have the hypothesized models been validated. This paper investigates human control behavior in pursuit tracking of a predictable reference signal while being perturbed by a quasi-random multisine disturbance signal. An experiment was done in which the relative strength of the target and disturbance signals were systematically varied. The anticipated changes in control behavior were studied by means of an ARX model analysis and by fitting three parametric HC models: two different feedback models and a combined feedforward and feedback model. The ARX analysis shows that the experiment participants employed control action on both the error and the target signal. The control action on the target was similar to the inverse of the system dynamics. Model fits show that this behavior can be modeled best by the combined feedforward and feedback model.}, web_url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6425447}, state = {published}, DOI = {10.1109/TSMCB.2012.2235829}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; Damveld HJ; van Paassen MM; Mulder M} } @Inproceedings{ DropPvMB2013, title = {Feedforward and Feedback Control Behavior in Helicopter Pilots during a Lateral Reposition Task}, year = {2013}, month = {5}, pages = {1797-1811}, abstract = {Pure feedback and pure open-loop feedforward helicopter pi lot models are currently applied for predicting the performance of pilot-helicopter systems. We argue that feedback models are likely to underestimate performance in many realistic helicopter maneuvers, whereas inverse simulation models, which have an open-loop feedforward structure, are likely to overestimate performance as they neglect typical human-in-the-loop characteristics. True verification of feedback and feedforward elements in helicopter pilot control behavior was never performed, however. This paper proposes a pilot model containing a feedback and feedforward controller acting simultaneously and presents a method to identify the hypothesized feedforward action from human-in-the-loop data collected in a simulator experiment. The results of the human-in-the-loop experiment show that actual human performance is better than predicted by a pure feedback model and worse than predicted by an (inverse dynamics) feedforward model. The identification results suggest that the human pilot indeed utilizes feedforward strategies, but it was not possible to either confirm or refute the model by means of the collected data and the developed analysis method.}, file_url = {fileadmin/user_upload/files/publications/2013/AHS-2013-Drop.pdf}, web_url = {http://vtol.org/publications/proceedings/ahs-forum-69-best-papers}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {69th American Helicopter Society International Annual Forum (AHS 2013)}, event_place = {Phoenix, AZ, USA}, state = {published}, ISBN = {978-1-62748-651-4}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; van Paassen MM; Mulder M; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}} } @Inproceedings{ DropPDVM2012_2, title = {Identification of the Transition from Compensatory to Feedforward Behavior in Manual Control}, year = {2012}, month = {10}, pages = {2008-2013}, abstract = {The human in manual control of a dynamical system can use both feedback and feedforward control strategies and will select a strategy based on performance and required effort. Literature has shown that feedforward control is used during tracking tasks in response to predictable targets. The influence of an external disturbance signal on the utilization of a feedforward control strategy has never been investigated, however. We hypothesized that the human will use a combined feedforward and feedback control strategy whenever the predictable target signal is sufficiently strong, and a predominantly feedback strategy whenever the random disturbance signal is dominant. From the data of a human-in-the-loop experiment we conclude that feedforward control is used in all the considered experimental conditions, including those where the disturbance signal is dominant and feedforward control does not deliver a marked performance advantage.}, web_url = {http://www.smc2012.org/}, publisher = {IEEE}, address = {Piscataway, NJ, USA}, event_name = {IEEE International Conference on Systems, Man, and Cybernetics (SMC 2012)}, event_place = {Seoul, South Korea}, state = {published}, ISBN = {978-1-4673-1713-9}, DOI = {10.1109/ICSMC.2012.6378033}, author = {Drop FM{fdrop}{Department Human Perception, Cognition and Action}; Pool DM{dpool}{Department Human Perception, Cognition and Action}; Damveld HJ; van Paassen MM; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Mulder M} } @Inproceedings{ OlivariNVBP2012, title = {Multi-loop Pilot Behavior Identification in Response to Simultaneous Visual and Haptic Stimuli}, year = {2012}, month = {8}, pages = {892-914}, abstract = {The goal of this paper is to better understand how the neuromuscular system of a pilot, or more generally an operator, adapts itself to di erent types of haptic aids during a pitch control task. A multi-loop pilot model, capable of describing the human behaviour during a tracking task, is presented. Three di erent identi cation techniques were investigated in order to simultaneously identify neuromuscular admittance and the visual response of a human pilot. In one of them, the various frequency response functions that build up the pilot model are identi ed using multi-inputs linear time-invariant models in ARX form. A second method makes use of cross-spectral densities and diagram block algebra to obtain the desired frequency response estimates. The identi cation techniques were validated using Monte Carlo simulations of a closed-loop control task. Both techniques were compared with the results of another identi cation method well known in literature and based on cross-spectral density estimates. All those methods were applied in an experimental setup in which pilots performed a pitch control task with di erent haptic aids. Two di erent haptic aids for tracking task are presented, a Direct Haptic Aid and an Indirect Haptic Aid. The two haptic aids were compared with a baseline condition in which no haptic force was used. The data obtained with the proposed method provide insight in how the pilot adapts his control behavior in relation to di erent haptic feedback schemes. From the experimental results it can be concluded that humans adapt their neuromuscular admittance in relation with di erent haptic aids. Furthermore, the two new identi cation techniques seemed to give more reliable admittance estimates.}, file_url = {fileadmin/user_upload/files/publications/2012/Olivari2012.pdf}, web_url = {http://arc.aiaa.org/doi/abs/10.2514/6.2012-4795}, publisher = {Curran}, address = {Red Hook, NY, USA}, event_name = {AIAA Modeling and Simulation Technologies Conference 2012}, event_place = {Minneapolis, MN, USA}, state = {published}, ISBN = {978-1-62410-183-0}, DOI = {10.2514/6.2012-4795}, author = {Olivari M{molivari}{Department Human Perception, Cognition and Action}; Nieuwenhuizen FM{fmnieuwenhuizen}{Department Human Perception, Cognition and Action}; Venrooij J{jvenrooij}{Department Human Perception, Cognition and Action}; B\"ulthoff HH{hhb}{Department Human Perception, Cognition and Action}; Pollini L} } @Poster{ CarpiFGGD2011, title = {Towards variable‐stifness dynamic hand splints based on dielecric elastomer transducers}, year = {2011}, month = {6}, number = {2.3.16}, abstract = {Patients who are affected by motor disorders of the hand and have residual voluntary movements of fingers can benefit of self-rehabilitation programs to be performed by means of so-called dynamic hand splints. These systems consist of orthoses equipped with elastic bands or springs which exert a passive resistance to voluntary elongations of one or more fingers. So, such systems allow for rehabilitation of fingers that still can voluntarily be moved against the recovery force of the counteracting elastic component. Although attractively simple, this approach is limited by the impossibility of modulating the counteracting action in real time. This does not allow for customized training and real-time control of the rehabilitation exercise, which might desirable to improve the rehabilitation efficacy. To solve this problem, electromechanically active versions of dynamic hand splints are needed. To address this issue with a solution relying on compact and light-weight devices, we are currently studying possible benefits of using dielectric elastomer (DE) transducers as variable-stiffness devices. The transducer is connected to a tendon wire, to be pulled and released by the user, and to a load cell. A processing unit controls the stiffness, so as to train the patient according to desired rehabilitation plans. This presentation shows the current stage of implementation of this concept using a multilayer transducer made of the PolyPower DE film.}, file_url = {fileadmin/user_upload/files/publications/2014/EuroEAP-2011-Gerboni.pdf}, web_url = {http://win.euroeap.eu/proceedings/ProceedingsShow.aspx?Event_ID=3}, event_name = {First International Conference on Electromechanically Active Polymer Transducers & Artificial Muscles (EuroEAP 2011)}, event_place = {Pisa, Italy}, state = {published}, author = {Carpi F; Frediani G; Gerboni CA{cgerboni}; Gemignani J; De Rossi D} }