José Solaz

Kinematics of the trunk in sitting posture: an analysis based on the instantaneous axis of rotation.

This paper presents a new approach for analysing trunk kinematics in sitting posture based on the characterisation of thorax and pelvis motion by means of ranges of motion and instantaneous axes of rotation (IAR). These variables are estimated from videophotogrammetric data. An experiment was carried out in order to analyse three motions associated with the flexion–extension movement: the absolute motions of the pelvis and thorax and the relative motion between the thorax and pelvis. The results obtained suggest a sequential activation of lumbar vertebrae in the flexion–extension motion. On the other hand, the location of the pelvis IAR shows that the movement of the pelvis on the seat is not just a rolling motion but a rolling with some level of sliding. Finally, the location of the IAR in the thorax-pelvis relative motion shows a mismatch between the trunk IAR and the backrest axis of rotation in several office chairs. The proposed technique provides a new approach for the kinematic analysis of sitting posture. The results can be applied to the improvement of biomechanical models of seated posture as well as to define some design criteria of work seats based on the fit between the trunk and backrest movements.

A Methodological Approach to the Determination of the Cause-Effect Relations in Automotive Seating Comfort

Comfort in automobile seats is multifactorial and extremely complex problem. Many of the current sophisticated measuring tools are underexploited if they are not framed into a clear methodological approach. The goal of this paper is to present the application of the user oriented methodology for the generation of design criteria in automobile seats design. With this purpose, each tool is set in a conceptual cause-effect scheme in the seat analysis process, from an ergonomic point of view. As a practical application, three different nowadays driver seats are evaluated using this model by means of laboratory testing and an experimental set with 6 people in a long-term driving simulation test.

A Car-Seat Example of Automated Anthropomorphic Testing of Fabrics Using Force-Controlled Robot Motions

For the last years, automation is widely used to relieve humans from repetitive tasks, primarily and firstly within manufacturing. However, for products with less ideal (or hard to model) properties, and when forces depends on human interaction, auto mated testing has not been explored until now. This work presents the analysis of the (human-dependent) motions/forces based on a fully implemented test case for car-seat testing. For emulation of the corresponding mechanical wear, an experimental test bench was developed. A sensor mat with a pressure gauge net was used in the test bench to determine the relevant loads, and the corresponding movements performed by the humans when sitting in a car seat were acquired by means of a photogrammetry system. Finally, to automate the reproduction of such movements by means of a dummy held by a robot, several controllers have been developed to regulate the force applied by the dummy on the seat. Simplicity and force-control performance for the human replication was also investigated in this work, showing the benefit of freely programmable (open) force control. The developed system has many practical applications, as allowing the analysis of the wearing caused by these movements on the seat upholstery. Thus, force controlled testing of fabrics using robots is a viable option.

SIMON: Integration of ICT Solutions for Mobility and Parking

Mobility and parking in urban areas are often difficult for people with disabilities. Obstacles include lack of accessible information on routes, transport alternatives and parking availability, as well as fraud in the use of the specific services intended for these citizens. The SIMON project aims to improve this situation through the integration of different ICT solutions, including a new model for the European Parking Card for disable people with contactless technologies to support user unique identification in existing parking areas whilst preserving privacy. SIMON has also developed solutions for mobility including information, navigation and access to restricted areas.

Experimental procedure for measuring and comparing head–neck–trunk posture and movements caused by different progressive addition lens designs

This study demonstrates that appropriate measurement procedures can detect differences in head movement in a near reading task when using three different progressive addition lenses (PALs). The movements were measured using an anatomical reference system with a biomechanical rationale. This reference system was capable of representing rotations for comparing head flexion relative to trunk, head flexion relative to neck, head rotation relative to trunk and trunk flexion. The subject sample comprised 31 volunteers and three PAL designs with different viewing zones were selected. Significant differences were found between the lenses for three of the seven movement parameters examined. The differences occurred for both vertical and horizontal head movements and could be attributed to aspects of the PAL design. The measurement of the complete kinematic trunk–neck–head chain improved the number of differences that were found over those in previous studies. Statement of Relevance: The study proposes a methodology based on a biomechanical rationale able to differentiate head–neck–trunk posture and movements caused by different progressive addition lens designs with minimum invasiveness. This methodology could also be applied to analyse the ergonomics of other devices that restrict the users field of view, such as helmets, personal protective equipment or helmet-mounted displays for pilots. This analysis will allow designers to optimise designs offering higher comfort and performance.

Desarrollo de un Banco de Pruebas Experimental mediante Control de Fuerza con Robot Industrial para el Análisis de la Respuesta Mecánica de Asientos de Coche

Los autores desean expresar su agradecimiento al Plan Nacional de I+D, Comision Interministerial de Ciencia y Tecnologia (CICYT) y a la Conselleria de Educacio de la Generalitat Valenciana por la financiacion parcial de este trabajo bajo los proyectos DPI2005-08732-C02-02, DPI2005-09327-C02-01 y GVPRE/2008/375. Asi mismo, los autores agradecen la ayuda prestada por Anders Blomdell por su trabajo en el desarrollo de la arquitectura abierta de control de los controladores industriales de ABB.

Heuristic Models Applied to the Assessment and Redesign of Human Machine Interfaces Embedded in Light Rail Vehicles

Abstract This paper describes the utilization of a heuristic tool for analysing the intrinsic complexity and usability of an HMI (Human-Machine Interface) of the on board information system embedded into the light rail CITADIS (vehicle manufactured by Alstom Transport). The usefulness of this tool is assessing early designs of this kind of equipment, prior to its implementation in a functional platform, or even in the rolling stock.