The contribution of closed loop tracking control of motion platform on laterally induced postural instability of the drivers at SAAM dynamic simulator

This paper explains the effect of a motion platform closed loop control comparing to the static condition for driving simulators on postural instability. The postural instabilities of the participants (N=18, 15 male and 3 female subjects) were measured as lateral displacements of subject body centre of pressure (YCP ) just before and after each driving session via a balance platform. After having completed the experiments, the two-tailed Mann-Whitney U test was applied to analyze the objective data for merely the post-exposure cases. The objective data analysis revealed that the YCP for the dynamic case indicated a significant lower value than the static situation (U(18), p < 0,0001). It can be concluded that the closed loop tracking control of the hexapod platform of the driving simulator (dynamic platform condition) decreased significantly the lateral postural stability compared to the static operation condition. However the two-tailed Mann-Whitney U test showed that no significant difference was obtained between the two conditions in terms of psychophysical perception

A robotic mobile platform for service tasks in cultural heritage

Recently, the preservation and survey of cultural heritage goods is attracting increasing interest from the media. Several famous historical sites seem to require an increased effort to maintain their preservation. Nevertheless, it is very difficult to find sufficient funds and human resources to fulfil these needs. Accordingly, this paper outlines a specific application of service robotics to cultural heritage, with the aim to reduce the required time and costs for surveying and maintaining cultural heritage goods. These applications require careful attention paid to the proper design of a robotic mobile platform with the features necessary to fulfil tasks of architectonic survey and preservation. To this end, specific operation scenarios have been carefully described in order to identify the specific design requirements and constraints that are raised by, for example, the necessity of operation over delicate surfaces, or the presence of unevenness or obstacles. The authors then propose a design solution for a service robot fit for the analysis, survey and conservation of historical sites, as based on the characteristics of the outlined scenarios. A preliminary prototype is also described herewith, in order to show its engineering feasibility in relation to the simulated operation scenarios

Expectation Management in a Global Collaboration Project Using a Deterministic Design Approach

Expectation management in product engineering design aims at setting achievable goals for both customers and designers, while leaving room for creativity and passion. This is especially challenging in the global workplace. Using an example of a design project, the Dental Headrest project (DHR), this paper reviews how expectations were managed in a successful, collaborative project between the University of Tokushima (UT) and Massachusetts Institute of Technology (MIT). The goal of the project was to design an innovative mechanism for the positioning a dental chair headrest so satisfy both the needs of a patient for comfort and a clinician for flexibility and access. The design team was formed with six students from the MIT MechE’s Precision Machine Design class, while the challenge proposed by a UT team of dentists and design engineers. The team followed a deterministic design procedure inducing understating the challenge and reviewing prior art, strategy and concept generation, detailed module design and fabrication and testing, culminating in presentation and documentation. Through the process was coordinated by online communication and collaborative working spaces which ensured real-time information transfer between the continents. The conclusion was a face-to-face meeting between the two institutions. This DHR project resulted in an innovative design of headrest adjusting mechanism that was implemented in a prototype. Moreover, the students, faculty and clinicians benefitted from the experience of innovative design collaboration in a multidisciplinary, global team.CIMIT: Center for Integration of Medicine and Innovative TechnologyJ. Morita Corporatio

Motion sickness evaluation and comparison for a static driving simulator and a dynamic driving simulator

This paper deals with driving simulation and in particular with the important issue of motion sickness. The paper proposes a methodology to evaluate the objective illness rating metrics deduced from the motion sickness dose value and questionnaires for both a static simulator and a dynamic simulator. Accelerations of the vestibular cues (head movements) of the subjects were recorded with and without motion platform activation. In order to compare user experiences in both cases, the head-dynamics-related illness ratings were computed from the obtained accelerations and the motion sickness dose values. For the subjective analysis, the principal component analysis method was used to determine the conflict between the subjective assessment in the static condition and that in the dynamic condition. The principal component analysis method used for the subjective evaluation showed a consistent difference between the answers given in the sickness questionnaire for the static platform case from those for the dynamic platform case. The two-tailed Mann–Whitney U test shows the significance in the differences between the self-reports to the individual questions. According to the two-tailed Mann–Whitney U test, experiencing nausea (p = 0.019 < 0.05) and dizziness (p = 0.018 < 0.05) decreased significantly from the static case to the dynamic case. Also, eye strain (p = 0.047 < 0.05) and tiredness (p = 0.047 < 0.05) were reduced significantly from the static case to the dynamic case. For the perception fidelity analysis, the Pearson correlation with a confidence interval of 95% was used to study the correlations of each question with the x illness rating component IRx, the y illness rating component IRy, the z illness rating component IRz and the compound illness rating IRtot. The results showed that the longitudinal head dynamics were the main element that induced discomfort for the static platform, whereas vertical head movements were the main factor to provoke discomfort for the dynamic platform case. Also, for the dynamic platform, lateral vestibular-level dynamics were the major element which caused a feeling of fear

Locomotion Control of Hexapod Walking Robot with Four Degrees of Freedom per Leg

V této práci představujeme nového šestinohého robota jménem HAntR, kterého jsme vytvořili dle potřeb Laboratoře výpočetní robotiky Centra umělé inteligence fakulty Elektrotechnické Českého vysokého učení technického v Praze. Jeho hlavním účelem jest vylepšit schopnosti pohybu v těžkém terénu původního robotu přidáním čtvrtého stupně volnosti každé noze. Na základě nově navržené nohy jsme také přepracovali celé tělo robotu tak, aby splnilo i další požadavky, jako například menší rozměry, či možnost osazení alespoň šesti Lithium-Iontovými monočlánky. V práci pečlivě popisujeme motivace a úvahy, které nás k výslednému návrhu vedly. Uvádíme řešení přímé i inverzní kinematické úlohy řešené pomocí podmínky na ideální orientaci konce nohy a uvažující i důležité kinematické singularity. Navržený robot byl vyzkoušen v několika experimentech, při kterých byl použit námi navržený řídicí systém napsaný v jazyce C++. Ukázalo se, že HAntR vydrží díky zvýšené energetické hustotě a lepšímu rozkladu sil v končetinách autonomně fungovat přes hodinu. Robot je také schopen jít rychlostí až 0.42m/s, což předčí mnohé srovnatelné roboty. Při experimentu, kdy robot stál na nakloněné rovině, bylo prokázáno zlepšení oproti předchozímu robotu. A také jsme dle pokynů této práce potvrdili, že i HAntR je schopen adaptivní chůze spoléhající pouze na poziční zpětnou vazbu.In this thesis a novel six-legged robot called HAntR is presented. The robot was developed according to needs of the Robotics Laboratory, at the Artificial Intelligent Center, Faculty of Electrical Engineering, Czech Technical University in Prague. Its main purpose is enhancing rough-terrain movement capabilities by upgrading a former design by adding fourth degree of freedom to each leg. We also revised robot torso to fit new leg design and incorporate other requirements such as smaller dimensions with space for at least six Lithium-Ion cells. We thoroughly describe motivations and considerations that led us to the presented particular solution. Further, the solutions of forward and inverse kinematic tasks with partial orientation constraint and important singularities avoidance are presented. The proposed design has been evaluated in several experimental deployments, which utilised developed software controller written in C++. Endurance tests showed, that HAntR is able to remotely operate for over an hour thanks to increased energy density. Maximal speed test resulted to 0.42m/s during tripod gait, which outpaces most of the comparable robotic platforms. Experiment where HAntR stood on platform with varying inclination showed qualitative improvement against former robot. Finally, in accord with the thesis assignment, we proved that HAntR is able to perform walking with adaptive gait using positional feedback only

An Internet Robot Tele-operating System

Abstract-A server-decentralized internet model based on Jabber for robot tele-operation with P2P stream media transfer supplement based on JXTA is proposed. The system is composed of four components: operators, robots, transfer servers and datakeeper. The robot-controlling data/robot state data are packed with XML stanzas and delivered to the resolved robot/operator through XML streams. The locale audio/video media streams of the robot are sent directly through P2P pipes to the operators. In order to test its availability and performance, the model is implemented and instanced as remote control systems for Virtual Puma560 robot and the Hexapod Monster robot. Experiments of the systems and network tests are carried out to evaluate the instances; the results show that the systems are suitable for many kinds of robot tele-operation scenarios despite the tough network environment