New Ergonomic Study of the railway driving cabins and comparison with the norm UIC 651

L. Ciuffi1, V. Pascuzzi1, P. Pignato1, E. Maestrini2, E. Mingozzi2, G. Roattino2, G. Casini2,

1Carcerano, Turin, Italy; 2Trenitalia S.p.A., Florence, Italy

Abstract

This research’s objective is creating a scientific and repeatable method for ergonomic analysis of the driving lay-out, in order to: • analyse and define technical solutions based on a “User Centered” approach for the trains’ driving cabin in the whole Trenitalia’s rolling stocks, using virtual prototyping; • verify the norm UIC 651 [1] applied on a sample of Trenitalia vehicles and the integration, if necessary, of current indications with ergonomics’ guidelines; • the definition of new cabins’ layout. • The method studied for such objectives is made by 4 steps; sequentially: euristics, analysis and field test, synthesis and elaboration in virtual environment ,engineering project, field experimentation. 1. At first the euristic analysis and field test: basing the study on the indications collected from the bibliography, we evaluate the driver’s activity observing the driving Tasks in their real contest of use. The method proposes two kind of observations: one in ‘static’ where a number of drivers simulates the driving activity; the second in ‘dynamic’ during the daily activity; both of them are due to highlight when and how the machinist incurs an uneasiness accomplishing his work’s tasks. The analysis in static are supported by interviews to the drivers (the observer follows always the same outline) and by measurements of postural angles; both the analysis make use of videotapes recording by three video-cameras set perpendicularly to the driver inside the cabin and questionnaires of evaluation of the working space. In the meantime the anthropometrical identification of each machinist is developed without any connection with the personal information. This anthropometrical survey is held inside the Trenitalia rolling Stocks and on the machinists who are due to be videotaped during the ride. These data will be elaborated in digital during the Phase of Synthesis and Elaboration. Building the Avatars, the norm UIC 651 is a reference: maximum is a subject 1900 mm tall, minimum limit is referred to Trenitalia’s acceptance: 1550 mm [2]. The percentiles used for the simulation are the subject 1900 mm tall, an avatar 1550 mm tall and 5° female percentile and 95° male percentile have exactly the dimensions in relief from Trenitalia’s personal. During the analytics phase, the collected data are observed. Comments expressed in questionnaires and interviews are summed to subjective indications about the user activity, the environment perception, the commands’ use and proposal of changes. The recorded videotapes give a feedback about the actual driving habits that are due to be associated to the anthropometrical dimensions in relief and the opinion expressed about the contest of use. 2. The synthesis and elaboration in virtual environment phase starts from the data input (2D drawings) received by Trenitalia. Starting from these input it is possible to: reconstruct the cabin in a Virtual Environment, introduce the Trenitalia’s Population Avatars inside the simulation, analyse the results coming from the application of the UIC norm 651 [1].

Proceeding with the postural ergonomic analysis, the visibility conditions (external signals and instruments) , reachable and use of controls, the dashboard layout and the posture analysis are considered priority.

Figure 1: Verification of visibility’s condition based on norm UIC 651 indications

It’s also possible to reproduce different typologies of driver and then verify usability conditions for machinists clusters, different from the interviewed ones. This methodology defines postural comfort’s parameters comparing ranges indicated by Ergonomics’ bibliography [3] with angular taken during driving activity.

Figure 2: Postural Comfortable Excursions - Side View.

Figure 3: Postural Comfortable Excursions – Top and Front View. “The Task Analysis is the first step to the project of the work” (EN614-2). Leading to this target it’s necessary to observe or suppose the actions that constitute each task; describe their critical aspects; analyse space, environment and the work organization; evaluate the necessary posture to accomplish the task. Thanks to the support of the Virtual Simulation, the method lets to • describe the static and dynamic simulation of the real mission,

• define how the actual posture has to change, qualitatively and quantitatively: all the chosen postural parameters are transferred inside the Virtual Environment applying them to the Avatars; it’s evaluated how, from the imposed comfortable posture the driver develops the tasks using each device of the system; 3. Project engineering • describe all the possible corrective interventions and the consequent technical solutions realizing them inside the 3Dmodel; • evaluate between different possible technical solutions, which one is the most usable; • propose the elimination of inconveniences’ elements or the introduction of ameliorative measures. • realize technical drawings as support to the production and installation.

Figure 4: Simulation of the driver’s activities 4. Field experimentation This methodology uses the Virtual Reality as a valid instrument to take the first basic decision inside a project but it is always necessary a confirmation inside the real working environment. Starting from this critic point of view, the Project of Train cabins is followed by a experimentation phase during which there is • the presentation of the Project and the instructions of ergonomic use for each new device; • a test of use on a static cabin, during which each machinist experiences the new working environment; • a test of use on a running cabin, during which each machinist experiences the new practice of driving; • the compilation of an evaluation questionnaire in which, after experiencing the cabin in a static and dynamics test, the drivers can express his impressions about the project; • a debriefing phase to collect all these feedbacks. Future development Starting from a deep analysis of the existing cabin, it’s possible to find ergonomic common parameters and needs to provide design guidelines for the interiors of new driving cabin. Ideal postures of use are related to the devices’ dashboard to give univocal answers to the industrial design. The ergonomic optimisation obtained by the described method’ is an integration and implementation of the norm UIC 651.

Figure 5: Driving dashboard – Reachable Area – Comparison with the UIC norm specifications [3].

"what's new?"

The individuation of an ergonomic investigation method, objective and retrievable in time; adequate to the peculiarities of Trenitalia, but completely replicable, developed integrating work analysis and virtual analysis’ techniques and with an engineering improvement of solutions. All this contributes to adequate the norm to the real necessities of comfort for the drivers’ activity.

References [1] CODE UIC 651, “Constitution des cabines de conduite des locomotives, automotrices, rames automotrices et voitures-pilotes”. 4e édition, (juillet 2002). [2] “Comunicazione per il Certificato di Sicurezza“ (CCS) n° 4/AD Trenitalia S.p.A. (2001) [3] Vittorio Pascuzzi, “Aspetti ergonomici nella progettazione delle cabine motrici ferroviarie.”, COREP, Torino, 2005. [4] Other general references: ISO DIS 9355-4 Safety of machinery — “Ergonomic requirements for the design of displays and control actuators“ — Part 4: Location and arrangement of displays and control actuators K.H.E. Kroemer e E: Grandjean: “Fitting the task to the man“ , Taylor & Francis, London, (1997) Pheasant S: “Bodyspace: anthropometry, ergonomics and the design of work “, Taylor & Francis, London, (1996).

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