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The recent development of motorcycle simulators has made it possible to study rider behavior in safe conditions. However, their use still raises validity issues. Our study examined how riders' steering and gaze behaviors and subjective experience are influenced by motorcycle roll tilt and reverse steering, which are considered to be essential factors in real-life motorcycle riding. The results revealed that tilting the motorcycle in the roll plane did not lead to significant changes in rider behavior, gaze sampling, or perceived realism. The steering control strategy adopted by riders did, however, significantly influence these results. A direct steering control strategy meant that riders took a racing path and scanned the road far in advance. When reverse steering was implemented, however, riders chose to take a "safety path", as recommended by training manuals. Reverse steering also received the highest realism score. However, steering control was more difficult, as shown by the larger number of lane departures recorded and a change in the trade-off between guiding and look-ahead fixations. This suggests that although reverse steering matches riders' real control behavior and improves the subjective experience of simulator riding, it is hindered by an inadequate internal model of vehicle dynamics. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

21st Congress of the International Ergonomics Association (IEA 2021), VANCOUVER, CANADA, 14-/06/2021 - 18/06/2021; International audience; Using an integrative user-centered approach, the research project aimed at designing and assessing an adaptive HMI to improve the safety and the quality of the take-over in a level-3 automated vehicle. Future autonomous driving users confirmed the need for the monitoring systems to improve safety as long as they are simple and not intrusive. They request specific information to understand and initiate appropriated actions in case of a critical situation. However, to avoid overloading and detri-mental effects, it is important that the system limits the amount of infor-mation at the right moment.

When manually steering a car, the driver’s visual perception of the driving scene and his or her motor actions to control the vehicle are closely linked. Since motor behaviour is no longer required in an automated vehicle, the sampling of the visual scene is affected. Autonomous driving typically results in less gaze being directed towards the road centre and a broader exploration of the driving scene, compared to manual driving. To examine the corollary of this situation, this study estimated the state of automation (manual or automated) on the basis of gaze behaviour. To do so, models based on partial least square regressions were computed by considering the gaze behaviour in multiple ways, using static indicators (percentage of time spent gazing at 13 areas of interests), dynamic indicators (transition matrices between areas) or both together. Analysis of the quality of predictions for the different models showed that the best result was obtained by considering both static and dynamic indicators. However, gaze dynamics played the most important role in distinguishing between manual and automated driving. This study may be relevant to the issue of driver monitoring in autonomous vehicles.

International audience; During highly automated driving, drivers no longer physically control the vehicle but they might need to monitor the driving scene. This is true for SAE level 2, where monitoring the external environment is required; it is also true for level 3, where drivers must react quickly and safely to a take-over request. Without such monitoring, even if only partial, drivers are considered out-of-the-loop (OOTL) and safety may be compromised. The OOTL phenomenon may be particularly important for long automated driving periods during which mind wandering can occur. This study scrutinized drivers’ visual behaviour for 18 min of highly automated driving. Intersections between gaze and 13 areas of interest (AOIs) were analysed, considering both static and dynamic indicators. An estimation of self-reported mind wandering based on gaze behaviour was performed using partial least squares (PLS) regression models. The outputs of the PLS regressions allowed defining visual strategies associated with good monitoring of the driving scene. This information may enable online estimation of the OOTL phenomenon based on a driver’s spontaneous visual behaviour.

International audience; Understanding a driver's behavior in a steering task is essential to the development of haptic guidance systems. This paper aims to predict driver torque control, especially when haptic guidance is part of haptic feedback. A new cybernetic driver model with an improved neuromuscular system is proposed and identified. It is assumed that the driver converts a target steering-wheel angle into torque by both indirect and direct control. Indirect control refers to the adaptation of the parameters of an internal model of steering compliance as perceived by the driver. Direct control accounts for the driver's corrective action through direct haptic feedback. The parameters of the model were identified with data collected from experiments conducted with a driving simulator. The results of identification were satisfactory and led to good representation of the driver's action, with or without haptic guidance. The model accurately predicted driver torque output. It can be used to study driver adaptation to haptic guidance systems.

International audience; This paper presents a methodology for the systematic synthesis of haptic shared control (HSC) of a car. This HSC design is based on a two-part architecture. The first part is a trajectory generator that provides a reference trajectory to the second part, which is a static output feedback. In this paper, the haptic shared control is used as an lane keeping assist system (LKA); hence, the reference trajectory is chosen to fulfill this function. The main contribution of this article is related to the combination of the H2/H∞ feedback synthesis. This, involves an H2 criterion quantifying the sharing level and quality as an objective function, and H2/H∞ constraints for lane-keeping performance, driver comfort and robustness. The control design relies on a driver cybernetic model, which decreases conflicts between the assistance and the driver. A systematic method to tune criterion and constraints is described, enabling the attainment of desired lane-following and shared-control performance. The proposed methodology facilitates the design of lateral assistance, ensuring stability and guaranteed performance regardless of the prescribed level of sharing between the actions of the driver and the automaton. The shared control between human driver and automation for the lane keeping task over the Satory test track with the sharing level adaptation is then shown for the validation of the proposed architecture. This work introduces perspectives on smooth transitioning between manual and autonomous driving modes.

International audience; Driver modeling is essential in the development of haptic guidance systems. A new cybernetic driver model designed to account for the cooperation between the driver and haptic guidance systems has recently been proposed. This paper aims to validate this model in situations of interaction with different levels of haptic guidance on a driving simulator. Two experiments have been performed for this purpose. The first experiment consisted of implementing the driver model in the driving simulator and evaluating its lateral control performance when interacting with a haptic guidance system. The results reveal that the model can be adapted to different sharing levels by adjusting only the gain of an internal model of the steering wheel compliance. The second experiment consisted of estimating the evolution of the gain of this internal model using the unscented Kalman filter. The results reveal consistency between the evolution of the identified parameter and the level of sharing of the haptic guidance system. The driver model represents the process of human driver adaptation to variations in the level of sharing in haptic guidance systems.

International audience; In autonomous cars, the automation systems assume complete operational control. In this situation, it is essential that passengers always feel comfort-able with the vehicle's decisions. In this project, we are specifically inter-ested in risk assessment by the passenger of an autonomous car navigating among pedestrians in a shared space. A driving simulator experiment was conducted with 27 participants. The challenge was twofold: on the one hand, to find a link between the pedestrians' avoidance behavior of the ve-hicle and the risk felt by the passenger; and on the other hand, to try to pre-dict this perceived risk in real time. The study revealed a significant effect of two factors on the risk assessed by the participants: (1) the value of the TTC at the moment the vehicle begins a pedestrian avoidance maneuver; (2) the lateral distance it leaves to the pedestrian. The proposed real-time pre-diction model is based on the principle of impulse response operation. This new paradigm assumes that the passenger's risk assessment is the result of a quantifiable unconscious internal phenomenon that has been estimated us-ing the dynamics of the perceived pedestrian approach. The results showed that this approach was predictive of risk for isolated avoidance maneuvers, but was insufficient to explain the variability in the risk assessment behav-ior of the participants.

International audience; This article presents an activity analysis carried out in an aeronautical factory. The representation of the real process and the operators’ representations were identified. The representation of the real process was elaborated using an abstraction hierarchy, as described by the ecological interface design framework. The operators’ representations were extracted through interviews and observations and described in terms of schemes. The analysis revealed that operators in the studied factory used misleading schemes (i.e., false representations) to organize their activities, resultingin poor performance.We conclude by offering possible remedies, including training aimed at inhibiting the misleading scheme and a simulation tool to convey a more accurate representation.

International audience; When sharing virtual collaborative environments, operators exchange spatial statements that refer to the objects’ positions in the virtual space. If operators are to understand each other, they need to develop a common spatial frame of reference and then choose a space coding to describe the objects’ positions. In this paper, we consider how the content of a virtual environment can influence communication between users. We designed two studies in which one participant (the speaker) had to indicate the position of one object to another participant (the addressee). The virtual environment was sometimes enriched by additional (proximal and distal) visual cues. In study 1, we considered statements production. We observed that the speakers most often used the avatar of their partner as a spatial reference to indicate a localization in the virtual space (i.e., Addressee-Centered coding) despite it increases their mental workload. Nevertheless, in complex situations, they also used distal cues to speak to the addressees (i.e., Exocentric coding of the space). In study 2, we considered statements comprehension. Addressee-Centered coding and Exocentric coding were used by the speakers in various spatial configurations to indicate the object position. We observed that Exocentric coding is the most difficult to manage for the addressee. These results indicate that speakers implemented the principle of less collaborative effort by adopting a way of exchanging information based on an asymmetrical cognitive cost, taking into consideration each other’s difficulties. This allows a balanced mental workload to be maintained between the two operators throughout the task.

International audience; Advanced Driver-Assistance Systems (ADAS) have become an essential part of modern cars. Among the solutions proposed, haptic shared control of the steering wheel is increasingly being studied. A fundamental question is how drivers adapt their behavior to these systems. This article proposes to use the Unscented Kalman Filter (UKF) to identify the variation over time in the psychological and neuromuscular parameters of a driver structured model. The goal here is to understand how the driver adapts to changes, whether regarding the behavior of the steering system, the visibility or the road conditions. The LPV system considered for identification is known as the cybernetic driver model. Two experiments carried out respectively with Simulink© and on a driving simulator provide the data. The methodology proposed for tuning the UKF is studied from the results obtained with those data. A multi-UKF strategy is also considered. The methodology reveals useful when a compromise between rapidity and precision has to be achieved for parameters estimation. It opens the way to a detailed analysis of the driver's parameter variations within the multi-UKF framework.

International audience; Haptic shared control is a consistent way to design an assistance for the lateral control of a vehicle. The most important problem raised by haptic shared control is to minimize useless conflicts between the driver and the assistance. To deal with, this paper proceeds in two stages. The first is concerned with feedforward synthesis in a new way, by identifying mainly the geometric part of driving from real driver data. The torque to apply to the steering wheel and more generally the reference trajectory is thus obtained from a second order model fed by the road curvature. Then, the feedback is designed based on a driver-vehicle-road model, using a mixed í µí°» 2 /í µí°» ∞ control synthesis involving both lane following performance and sharing capabilities indicators. Finally, the shared control strategy is simulated on Matlab/Simulink using a vehicle-road model. The results obtained show good features both in terms of lane following and sharing performances. This control strategy seems then to be an interesting candidate for haptic shared control.

International audience; The study presented here follows a former study, lead in a real aeronautical factory where operators control a semi-automated process of metallic frames stretching. The observations and interviews from this first study conducted to the identification of a misleading scheme. This misleading scheme consists in programming a stretching machine according to the results obtained on a precedent frame instead of using the inner frame characteristics. However, since studying this misleading scheme turned out to be complicated in the real factory, a micro-world, reproducing the factory activity was developed. This new article present the results obtained on this micro-world. First, the activity of twelve participants, who had never worked in the factory, was similar to the operator activity as they used the misleading scheme. Moreover, the micro-world showed that the misleading scheme brings a decrease in the performance of participants who were given more time on the micro-world. On the contrary, participant with little training always performed badly, whenever they used the misleading scheme or not. The results showed that the micro-world granted the access to a specific cognitive criterion, the misleading scheme, which was not easily accessible in the real factory. This results lead to two main recommendations: the first one states the importance to give the operator inhibition training against the misleading scheme; the second is with regard to the features an interface helping with the fabrication process should have. ACM Classification Keywords H.5.m. Information interfaces and presentation (e.g., HCI): Laboratory experiments. J.4: Social and behavioral sciences; L'étude présentée ici fait suite à une étude de terrain réalisée dans un atelier d'aéronautique où des opérateurs contrôlent un procédé semi-automatisé d'étirage de cadres métalliques. Des observations et entretiens avaient permis d'identifier un schème trompeur, qui se manifeste par l'utilisation des résultats obtenus sur un cadre afin de paramétrer une machine d'étirage pour un cadre suivant, alors que les propriétés physiques des cadres diffèrent entre eux. L'étude de ce schème s'étant révélée difficile dans l'atelier réel, un micromonde, reprenant les caractéristiques principales de l'atelier, a été développé. Ce nouvel article décrit les résultats obtenus sur ce micromonde. Le micromonde a permis de reproduire l'activité observée dans l'atelier chez douze participants tout-venants : ils ont mis en oeuvre le schème trompeur comme les opérateurs de l'atelier. De plus, dans le micromonde, le schème trompeur provoque une diminution des performances mais uniquement chez des participants ayant bénéficié de plus de temps d'entrainement sur le micromonde, les autres participants ayant dans tous les cas des résultats faibles. Les résultats montrent que l'utilisation du micromonde a permis dans ce cas d'étudier un élément cognitif spécifique, ici le schème trompeur, alors qu'il était difficile d'accès dans l'atelier. En outre, ces résultats aboutissent à deux préconisations principales : l'une concerne la nécessité d'une formation spécifique incitant les opérateurs à inhiber le schème trompeur, l'autre concerne le type d'interface à mettre en oeuvre dans un assistant au procédé de fabrication.

International audience; In the context of a remote collaboration task in virtual reality, this study aimed to analyze the effects of task distribution on the processing of spatial information and mental workload in spatial dialogs. Pairs of distant participants with specific roles (a guide and a manipulator) had to collaboratively move a virtual object in a plane factory mock-up. The displays allowed the participants to be immersed together in the virtual environment. We analyzed the dialogs that took place according to the frames of reference and the mental transformations required to produce the spatial statements. We also measured the associated mental workload. Results showed that when participants took a perspective, the manipulator’s point of view was preferred. Perspective-taking only yielded a moderate increase in mental rotations, which may explain a specifically high mental demand score for the guides’ NASA-TLX. Overall, this is in accordance with the least collaborative effort principle. This study reinforces the idea that, in collaboration, operators do not need the same aids as each other. Thus, it is not necessary to develop symmetrical tools, i.e., the same tools for all co-workers; instead, the needs of each operator should be taken into account, according to the task he has to perform. In our case, the guides would be helped with perspective-taking aids, while the manipulators would be helped with action-oriented tools.

International audience; Background: When guiding a remote collaborator in a virtual environment, people often take an addressee-perspective, which may have a high cognitive cost. In order to improve collaborative virtual environments, a better understanding of how operators share spatial information is needed.Aims: This work aimed to study the cognitive workload linked to spatial statements production in situations in which the relative positions of speaker, addressee and target were varied.Method: Twenty-two participants were asked to give - in one go - instructions to a virtual collaborator on how to find a target in a 3D environment. The scene showed an avatar in the center of eight tables. Sixty-four configurations of avatar orientation (eight possibilities) and target location (on the eight tables) were tested. We measured the delay in starting the instruction once the target appeared, the instruction duration, and the subjective evaluation of mental demand. Each instruction was classified according to the spatial reference frame used.Results: The delay was influenced by the processing of spatial information in ego-centered and addressee-centered reference frames. All subsequent measures were determined by mental transformations in addressee-centered coordinates. One condition in particular, when the target was situated diagonally behind the addressee, gave rise to a higher mental demand for the speaker, which points to the investment made by the speaker in achieving the least collaborative effort.Conclusions: Further work should seek to develop efficient tools to facilitate spatial communication in situations that induce the most mental workload.

International audience; Although the benefits of haptic shared control of the steering wheel have been repeatedly demonstrated, longitudinal studies of how drivers adapt to this kind of system are still lacking. The present study addressed this question by comparing two groups of participants in a driving simulator for an extended time period; one group drove with a shared control system and the other drove without. After the practice, all participants drove a final trial with shared control during which a failure of the system occurred. The results show that the evolution of driving performance and the way in which drivers monitored their performance was similar for the two groups. This suggests that the drivers quickly updated their internal model of the steering system dynamics at the sensorimotor level, without further behavioural adaptation afterwards. However, it appears that the internal model was consolidated with repeated use of the system, which translated as a difficulty to compensate for the system's failure. In addition, it appears that drivers did not attempt to maintain a level of task difficulty when steering was facilitated.

International audience; It has long been long held that steering a vehicle is subserved by two distinct visual processes, a compensatory one for maintaining lane position and an anticipatory one for previewing the curvature of the upcoming road. In this study we investigated the robustness of these two steering control processes by systematically degrading their visual inputs. Performance was measured at the level of vehicle position and at the level of the actions on the steering wheel. The results show that the compensatory process is more robust to visual degradation than the anticipatory process. The results are also consistent with the idea that steering is under the supervision of a combination of compensatory and anticipatory mechanisms, although they suggest that the quality of the sensory information will determine how information is combined.

International audience; Current theories on the role of visuomotor coordination in driving agree that active sampling of the road by the driver informs the arm-motor system in charge of performing actions on the steering wheel. Still under debate, however, is the nature of visual cues and gaze strategies used by drivers. In particular, the tangent point hypothesis, which states that drivers look at a specific point on the inside edge line, has recently become the object of controversy. An alternative hypothesis proposes that drivers orient gaze toward the desired future path, which happens to be often situated in the vicinity of the tangent point. The present study contributed to this debate through the analyses of the distribution of gaze orientation with respect to the tangent point. The results revealed that drivers sampled the roadway in the close vicinity of the tangent point rather than the tangent point proper. This supports the idea that drivers look at the boundary of a safe trajectory envelop near the inside edge line. Furthermore, the study investigated for the first time the reciprocal influence of manual control on gaze control in the context of driving. This was achieved through the comparison of gaze behavior when drivers actively steered the vehicle or when steering was performed by an automatic controller. The results showed an increase in look-ahead fixations in the direction of the bend exit and a small but consistent reduction in the time spent looking in the area of the tangent point when steering was passive. This may be the consequence of a change in the balance between cognitive and sensorimotor anticipatory gaze strategies. It might also reflect bidirectional coordination control between the eye and arm-motor systems, which goes beyond the common assumption that the eyes lead the hands when driving.

International audience; The work described in this paper is part of a larger research program named Partage whose goal is to appropriately share lateral control between the driver and an electronic copilot or assistance. The present study is looking for a cybernetic model of a driver steering road vehicle, which makes the sensorimotor dynamics explicit. The proposed model takes into account both visual and kinesthetic perception, and includes compensatory and anticipatory processes. As such, it extends previous works. Starting from simulated car trajectories, the unknown parameters of the model are identified using the grey box identification concept. The driver-vehicle system is then analyzed with respect to the parameter sensitivity.

International audience; This study investigated the link between drivers' gaze positioning and steering behavior when negotiating bends. This was conducted by directing the driver's point of gaze toward a target situated in the vicinity of the tangent point (TP), a region known to attract a significant amount of ocular fixations and thought to provide some useful input for anticipatory steering (M. F. Land & D. N. Lee, 1994). The orientation of gaze relative to the TP was manipulated and the resulting steering behavior was compared to that obtained with a free-gaze strategy. The data revealed that constraining eye movements did not impair steering behavior. On the contrary, the continuous tracking of the fixation point promoted smoother steering control, irrespective of the position of that point. This confirms that previewing the road curvature by tracking a distant point contributes to the stability of steering. The direction of the TP does not appear to be an essential parameter in that process (D. D. Salvucci & R. Gray, 2004). The results also indicate that continuously looking at the TP or further inside the bend yielded a deviation of the trajectory. This is consistent with the hypothesis that drivers look inside the lane boundaries to determine the future path (R. M. Wilkie & J. P. Wann, 2006).

International audience; Car driver modeling is a well-known research topic, with significant existing contributions. In contrast, important questions related to motorcyclist modeling remain unanswered. This study focuses on identifying a motorcyclist model that can predict the steering angle and the rider roll angle. A black box rider model in the form of a time delay neural network is presented. This model was developed using experimental data recorded with an instrumented motorcycle from the VIROLO++ research project. It is used for three main issues. First, the selection of input signals and their impact on prediction performance is discussed. Next, the model’s ability to predict the behavior of a variety of motorcyclists is demonstrated. Finally, the nonlinearity of the model is analyzed. These results pave the way to the development of a cybernetic rider model.