SAM

The role of motion platform on postural instability and head vibration exposure at driving simulators

AYKENT, Baris — Tue, 01 Jan 2013 00:00:00 GMT

The role of motion platform on postural instability and head vibration exposure at driving simulators AYKENT, Baris; PAILLOT, Damien; KEMENY, Andras; MERIENNE, Frédéric This paper explains the effect of a motion platform for driving simulators on postural instability and head vibration exposure. The sensed head level-vehicle (visual cues) level longitudinal and lateral accelerations (ax,sensed = ax_head and ay,sensed = ay_head, ayv = ay_veh and ayv = ay_veh) were saved by using a motion tracking sensor and a simulation software respectively. Then, associated vibration dose values (VDVs) were computed at head level during the driving sessions. Furthermore, the postural instabilities of the participants were measured as longitudinal and lateral subject body centre of pressure (XCP and YCP, respectively) displacements just after each driving session via a balance platform. The results revealed that the optic-head inertial level longitudinal accelerations indicated a negative non-significant correlation (r = −.203, p = .154 > .05) for the static case, whereas the optic-head inertial longitudinal accelerations depicted a so small negative non-significant correlation (r = −.066, p = .643 > .05) that can be negligible for the dynamic condition. The XCP for the dynamic case indicated a significant higher value than the static situation (t(47), p < .0001). The VDVx for the dynamic case yielded a significant higher value than the static situation (U(47), p < .0001). The optic-head inertial lateral accelerations resulted a negative significant correlation (r = −.376, p = .007 < .05) for the static platform, whereas the optic-head inertial lateral accelerations showed a positive significant correlation (r = .418, p = .002 < .05) at dynamic platform condition. The VDVy for the static case indicated a significant higher value rather than the dynamic situation (U(47), p < .0001). The YCP for the static case yielded significantly higher than the dynamic situation (t(47), p = .001 < 0.05).

Influence of a new discrete-time LQR-based motion cueing on driving simulator

AYKENT, Baris — Tue, 01 Jan 2013 00:00:00 GMT

Influence of a new discrete-time LQR-based motion cueing on driving simulator AYKENT, Baris; PAILLOT, Damien; KEMENY, Andras; MERIENNE, Frédéric This study proposes a method and an experimental validation to analyze dynamics response of the simulator's cabin and platform with respect to the type of the control used in the hexapod driving simulator. In this article, two different forms of motion platform tracking control are performed as a classical motion cueing algorithm and a discrete-time linear quadratic regulator (LQR) motion cueing algorithm. For each situation, vehicle dynamics and motion platform level data are registered from the driving simulation software. In addition, the natural frequencies of the roll accelerations are obtained in real-time by using FFT. The data are denoised by using wavelet 1D transformation. The results show that by using discrete-time LQR algorithm, the roll acceleration amplitudes that correspond to the natural frequencies and the total roll jerk have decreased at the motion platform level. Also, the natural frequencies have increased reasonably by using the discrete LQR motion cueing (1.5–2.2 Hz) compared with using the classical algorithm (0.4–1.5 Hz) at the motion platform, which is an indicator of motion sickness incidence avoidance. The literature shows that lateral motion (roll, yaw, etc.) in the frequency range of 0.1–0.5 Hz induces motion sickness. Furthermore, using discrete-time LQR motion cueing algorithm has decreased the sensation error (motion platform–vehicle (cabin) levels) two times in terms of total roll jerk. In conclusion, discrete-time LQR motion cueing has reduced the simulator sickness more than the classical motion cueing algorithm depending on sensory cue conflict theory.

Test-bench for evaluating navigation and interaction in large virtual databases

MIRZAEI, Mohammad Ali — Sun, 01 Jan 2012 00:00:00 GMT

Test-bench for evaluating navigation and interaction in large virtual databases MIRZAEI, Mohammad Ali; PÈRE, Christian; MERIENNE, Frédéric; CHARDONNET, Jean-Rémy 3D systems due to its complicated electronical, mechanical and vision accessories have enormous degree of complexity both in design and evaluation. Navigation system usually plays an important role in most 3D systems. Therefore, having an efficient navigation system and evaluation of the system has great deal of importance. 3D systems have a lot of parameters, inputs and outputs thus; evaluation process requires a complete test bench to collect and analyse maximum possible efficient parameters and variables. This paper will propose a test bench based on a tracker, navigation device status, and some biological and motion feedback from end-user to analyse a 3D system and associated navigation system performance. An original test procedure will be provided for evaluating navigation in 3D scenes by focusing on experimental aspects such as metric variable definition for measurement, case selection criteria and test-bed design. The novelty in our approach is the use of information given by the brain to understand the human perception in VE and to improve navigation in 3D scenes and interaction with virtual reality.

Influence of Inertial Stimulus on Visuo-Vestibular Cues Conflict for Lateral Dynamics at Driving Simulators

AYKENT, Baris — Tue, 01 Jan 2013 00:00:00 GMT

Influence of Inertial Stimulus on Visuo-Vestibular Cues Conflict for Lateral Dynamics at Driving Simulators AYKENT, Baris; PAILLOT, Damien; KEMENY, Andras; MERIENNE, Frédéric This paper explains the effect of having an inertial stimulus (motion platform) for driving simulators on proximity to the reality for the sensed lateral dynamics with respect to the measurements and the perceptual fidelity using a questionnaire technique. To assess this objectively, the vestibular and vehicle level lateral accelerations (ay,sensed=ay_ vest, ayv =ay_veh ) were saved by using a motion tracking sensor and SCANeR studio software respectively. A confidence interval of 95% was chosen to test the correlations (Pearson’s correlation) and to fit models for the distributions of the visual-vestibular lateral accelerations with the multiple linear regression between the conditions of static (N=16) and dynamic (N=21) platform cases in terms of visuo-vestibular level lateral accelerations for the group of subjects (N=37). The results showed that the dynamic platform provides a higher lateral dynamics reality (positive correlation with an incidence of 90.48% for N=21) compared to the static configuration (negative correlation with an incidence of 50% for N=16) from Pearson’s correlation and a better fitted model and a lower visuo-vestibular cues’ conflict for the dynamic (R2 =0.429, the model is positive sloped, N=21) condition comparing to the static one (R2 =0.072, the model is negative sloped, N=16) from the multiple linear regression models. A two-tailed Mann Whitney U test yielded that the Ucomputed (2139)>Uexpected (1300.5) as p<0.0001, there was a significant difference between the sensed lateral acclerations for the static and dynamic platform cases. Disorientation related perception had positive correlations with the vestibular sensed lateral accelerations for the static condition whereas they were negatively correlated in the dynamic case. As conclusion, the dynamic platform presented a reduced level of motion sickness depending on the sensory conflict theory and the perception fidelity studies approved that dizziness was found to have a significant positive correlation with the vestibular level measured lateral acceleration in the static platform (r=0.293, p=0.037<0.05). Version éditeur de cet article : Aykent B, Merienne F, Paillot D, Kemeny A (2013) Influence of Inertial Stimulus on Visuo-Vestibular Cues Conflict for Lateral Dynamics at Driving Simulators. J Ergonomics 3: 113. doi:10.4172/2165-7556.1000113

Designing a 3D Navigation System Using Cognitive Factors

MIRZAEI, Mohammad Ali — Sun, 01 Jan 2012 00:00:00 GMT

Designing a 3D Navigation System Using Cognitive Factors MIRZAEI, Mohammad Ali; PÈRE, Christian; MERIENNE, Frédéric; CHARDONNET, Jean-Rémy This paper focuses on the measurement and the mathematical definition of cognitive parameters of designing a navigation systembased on these parameters. The nausea level due to different velocities of a 3D scene, the user head rotation around Yaw, Roll and Pitch axes, the delay between navigation device stimuli and the 3D display movement are measured. Appropriate mathematical functions are ﬁtted to the measurements. A sickness level is deﬁned as an accumulation of a nausea level due to the velocity and the delay. Assigning an analog control button on the navigation device will help the user to adjust the speed. The records of the test-bed and practical experiments prove the effectiveness of this kind of design. Moreover, due to the parametric design of the system, any maloperation can be readjusted with further inquiries over the speciﬁc applications. In addition, any amendment or modiﬁcation performance can be compared with the parametric criteria.

A LQR washout algorithm for a driving simulator equipped with a hexapod platform : the relationship of neuromuscular dynamics with the sensed illness rating

AYKENT, Baris — Sun, 01 Jan 2012 00:00:00 GMT

A LQR washout algorithm for a driving simulator equipped with a hexapod platform : the relationship of neuromuscular dynamics with the sensed illness rating AYKENT, Baris; PAILLOT, Damien; KEMENY, Andras; MERIENNE, Frédéric This study proposes a method and an experimental validation to analyze dynamics response of the drivers with respect to the type of the control used in the hexapod driving simulator. In this article, two different forms of motion platform tracking control have been performed: - Classical motion cueing algorithm - LQR motion cueing algorithm For each situation, the EMG (electromyography) data have been registered from arm muscles of the drivers (flexor carpi radialis, brachioradialis). In addition, the acceleration based illness ratings (IR) have been computed. In order to process the data of the EMG and IR, the linear regression with a significance level of 0.05 has been assigned. Three cases have been evaluated: 1) Time exposure neuromuscular dynamics and vestibular–vehicle level conflict illness ratings 2) Time exposure neuromuscular dynamics and vestibular level sensed illness ratings 3) Impulse dynamics effect between the neuromuscular (EMG) and the vestibular dynamics (IR) The results have showed that: a) The vibration exposure condition: When the total RMS acceleration frequency weighted average IR increases, the EMG average total power increases too by driving the classical motion cueing algorithm. However, in contrast to this, the EMG average RMS total power decreases while the IR increases during the LQR motion cueing algorithm. b) Impulse effect condition: As the IR augments; the EMG average RMS total power also increases for the optimal motion cueing algorithm but it decreases for the classical algorithm.

Evaluation of Smartphone-based interaction techniques in a CAVE in the context of immersive digital project review

GEORGE, Paul — Wed, 01 Jan 2014 00:00:00 GMT

Evaluation of Smartphone-based interaction techniques in a CAVE in the context of immersive digital project review GEORGE, Paul; KEMENY, Andras; COLOMBET, Florent; MOUTTAPA THOUVENIN, Indira; MERIENNE, Frédéric; CHARDONNET, Jean-Rémy Immersive digital project reviews consist in using virtual reality (VR) as a tool for discussion between various stakeholders of a project. In the automotive industry, the digital car prototype model is the common thread that binds them. It is used during immersive digital project reviews between designers, engineers, ergonomists, etc. The digital mockup is also used to assess future car architecture, habitability or perceived quality requirements with the aim to reduce using physical mockups for optimized cost, delay and quality efficiency. Among the difficulties identified by the users, handling the mockup is a major one. Inspired by current uses of nomad devices (multi-touch gestures, IPhone UI look’n’feel and AR applications), we designed a navigation technique taking advantage of these popular input devices: Space scrolling allows moving around the mockup. In this paper, we present the results of a study we conducted on the usability and acceptability of the proposed smartphone-based interaction metaphor compared to traditional technique and we provide indications of the most efficient choices for different use-cases accordingly. It was carried out in a traditional 4-sided CAVE and its purpose is to assess a chosen set of interaction techniques to be implemented in Renault’s new 5-sides 4K x 4K wall high performance CAVE. The proposed new metaphor using nomad devices is well accepted by novice VR users and future implementation should allow an efficient industrial use. Their use is an easy and user friendly alternative of the existing traditional control devices such as a joystick.

Distance Perception During Cooperative Virtual Locomotion

MARSH, William Eric — Thu, 01 Jan 2015 00:00:00 GMT

Distance Perception During Cooperative Virtual Locomotion MARSH, William Eric; MERIENNE, Frédéric; CHARDONNET, Jean-Rémy Virtual distances are often misperceived, though most past research ignores co-located cooperative systems. Because active locomotion plays a role in spatial perception, cooperative viewpoint control may impact perceived distances. Additionally, the center of projection is generally optimized for a single tracked user, meaning that a single action will result in different visual feedback for each user. We describe a study investigating the effect of a co-located cooperative locomotion interface on virtual distance perception. Results indicate that a slight center-of-projection offset did affect distance estimates for the untracked user, but that the cooperation actions themselves did not play a role. This study brings new insights to designing interfaces which facilitate accurate spatial perception in cooperative applications.

Study of the Influence of Different Washout Algorithms on Simulator Sickness for a Driving Simulation Task

AYKENT, Baris — Sat, 01 Jan 2011 00:00:00 GMT

Study of the Influence of Different Washout Algorithms on Simulator Sickness for a Driving Simulation Task AYKENT, Baris; PAILLOT, Damien; FANG, Zhou; KEMENY, Andras; MERIENNE, Frédéric This paper deals with the effects of different washout algorithms used for Stewart platforms on subjective and objective ratings. Washout algorithms are used to represent vehicle dynamics in a restricted spatial place. An adaptive washout algorithm was realized to control the hexapod platform, depending on the specific force error in longitudinal, lateral and vertical directions, in order to compare user‟s experience with those in the case of classical algorithm. In this study, the simulator sickness has been evaluated for three algorithms in dynamic driving simulator situation in objective and subjective way.

Institut Image – Le2i

MARSH, William Eric — Thu, 01 Jan 2015 00:00:00 GMT

Institut Image – Le2i MARSH, William Eric; AYKENT, Baris; MARTINEZ, Jean-Luc; MERIENNE, Frédéric Institut Image is a department of Arts et Métiers ParisTech developing virtual reality (VR) for teaching, research, and innovation. The research team is composed of 30 people (teacher- researchers, engineers, PhD students) and is part of Le2i laboratory (CNRS lab). Institut Image hosts a master research program (15 students) and innovates through its technological platform PeTRiiV. Research activities are developed in strong relationship with industry. Several collaborative research programs are performed, including the VARI3 and Si2M projects presented briefly in this paper.