ATEV-Automatic spreadsheeT for the Ergonomic eValuation Development and Application of a software tool for the automatic ergonomic analysis in the industrial environment

The work described in the following thesis has been developed during an 8-month internship at FCA (FCA Italy S.p.A.) in Turin, under the supervision of Sebastiano Lamacchia. Dr. Lamacchia has worked for several years at the Fiat Research Centre as an expert of ergonomics applied to the industrial processes. He is currently covering multiple roles in World Class Manifacturing (WCM) and World Class Manifacturing Accademy (WCMA), both of which are FCA agencies. He is responsible for ergonomics standard applications training and works for contact and relationship with universities as well as in the development of technologies and application of virtual reality within the automotive industrial field. Alongside him, eng Lidia Ghibaudo, PhD, responsible for the Ergonomic Laboratory of FCA Italy in Turin, and engineer Maria Pia Cavatorta, professor of machine design and applied ergonomics at the Politecnico di Torino, have participated and given their support. The project is aimed at the optimization, debugging and evolution of an existing tool based on Microsoft Excel and visual basic programming language, performing an automatic ergonomics assessment. The human operator is wearing position sensors, which are usually employed for animation or recording purpose, during the working task. The activity is recorded, and data are imported into the Excel tool in which they are properly manipulated to reconstruct a wireframe virtual manikin and fill a given, thus not fixed, ergonomic standard worksheet. In order to achieve the expected result, several steps have been taken: the study of the position sensor system, the structure of the data and the way they have to be imported, and the wireframe reconstruction alongside with the computation of the correct ergonomic variables according to norms and ISO standards. Emphasis is given to the hands of the operator, which have been reconstructed and animated in an indirect way since the hands compound of sensor’s system was not available. Indeed, the posture of the hand is a key topic of the ergonomic analysis and its importance cannot be neglected. Once a standard hand wireframe scheme is created, the information regarding the orientation of the wrist in the space is extracted from the sensors database and a kinematic direct chain is applied to obtain the correct motion. Then, all the ergonomic variables are analysed and, if necessary, corrected. The most important variable is arguably the elbow pronation and supination, which represent critical points in this assessment. Once the basic tool has been optimized, a second development phase has been carried out trying to obtain the same result with a cheaper sensor system capable of recording a consistently lower amount of information. The obtained spreadsheet can be considered as flexible since it is possible to select a given output, which is not fixed, and implement the desired ergonomic worksheet. As a result of this feature, the second chapter of the project can proceed. The tool is used to analyse a working task and evaluate a different set of parameters. The goal is now to evaluate, on the basis of a given protocol, if the studied activity is appropriate from an objective point of view. This task will allow for the introduction of an Upper-limb exoskeleton device in the real working station inside the industrial production plant. The focus is thus shifted to a set of experimental procedures and trials aimed to the better understanding of the exoskeleton